JP2015090253A - Refrigerant recovery system and refrigerant recovery method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a refrigerant recovery system and a refrigerant recovery method that can perform refrigerant recovery work in a shorter time.SOLUTION: A refrigerant recovery system comprises a refrigerant recovery path 500 that recovers a gas refrigerant in a refrigeration air-conditioning device, a carrier gas introduction path 502 that introduces carrier gas into the refrigeration air-conditioning device, a pressure detection unit 5 that detects a pressure in the refrigeration air-conditioning device, and a control unit 11 that performs control on the basis of the pressure. The refrigerant recovery path 500 is provided with a compressor 40 that sucks the gas refrigerant to compress it, a condenser 41 that condenses the compressed gas refrigerant into a liquid refrigerant, and a refrigerant recovery container 42 that recovers the condensed liquid refrigerant. The carrier gas introduction path 502 is provided with a carrier gas supply unit 8 that supplies the carrier gas and flow rate adjustment means that adjusts a flow rate of the carrier gas to be introduced into the refrigeration air-conditioning device. The control unit 11 controls the flow rate adjustment means so that at least one of the pressure and a temperature is kept equal to or higher than a predetermined value.

Description

  The present invention relates to a refrigerant recovery system and a refrigerant recovery method.

  In general refrigeration and air-conditioning equipment typified by multi-air conditioners for buildings, an air-conditioning compressor that compresses refrigerant gas to high temperature and pressure and a high-temperature and high-pressure refrigerant on a circulation path of the refrigerant that conveys heat energy An air conditioning condenser that cools and liquefies gas with outside air, an expansion valve that expands and gasifies the liquefied refrigerant, a refrigerant recovery condenser that liquefies the refrigerant again, and stores liquid refrigerant And an accumulator. The refrigeration and air conditioning equipment releases heat to the outside in the air conditioning condenser, and cools and freezes them by receiving heat from outside air after passing through the expansion valve.

  However, since various refrigerants used in refrigeration and air conditioning equipment have a large global warming potential and ozone depletion potential, their emission into the atmosphere is regulated. Therefore, particularly when replacing the refrigerant or discarding the refrigeration and air conditioning equipment, it is obliged to suppress the leakage of the refrigerant to the atmosphere as much as possible and collect the refrigerant filled in the refrigeration and air conditioning equipment. At the same time, conversion to refrigerants with a low environmental load is also being promoted. From the CFCs (Chlorofluorocarbons) and HCFCs (Hydrofluorocarbons), which are called old refrigerants, recently, HFCs (Hydrofluorocarbons), especially mixed refrigerants, which are called new refrigerants. The use of R410A and R407C is the mainstream.

  For the recovery of the refrigerant, it is common to use a commercially available refrigerant recovery device. In this refrigerant recovery apparatus, gas refrigerant is sucked from the refrigeration air-conditioning equipment by a compressor in the refrigerant recovery apparatus, and the temperature and pressure are increased. The high-temperature and high-pressure gas refrigerant is liquefied by a condenser in the refrigerant recovery device, and filled and recovered as a liquid refrigerant in a recovery container. The recovered refrigerant amount is measured by a weigh scale, and the recovered amount and recovery rate are calculated. As described above, the refrigerant recovery operation itself is relatively easy because the refrigerant recovery apparatus automatically performs the operation. However, in such a conventional refrigerant recovery device, as the recovery proceeds, low-temperature condensation of the refrigerant, so-called refrigerant stagnation occurs, making recovery as a gas refrigerant difficult, contrary to the ease of refrigerant recovery work. It takes a lot of time as a problem. It is practically difficult to assign a long schedule as the recovery time in a defined work process, and such a trend can increase unrecovered refrigerant. Improvement of efficiency is recognized as a major problem.

  Patent Document 1 discloses a refrigerant recovery device that efficiently recovers a liquid refrigerant that lies in a refrigeration air conditioner. In this refrigerant recovery apparatus, the vaporized component of the liquid refrigerant once recovered in the recovery cylinder is sucked by a compressor, is increased in temperature and pressure, and is sent back to the refrigeration and air conditioning equipment. Thereby, the vaporization of the liquid refrigerant in the refrigeration air conditioner is promoted, and the refrigerant recovery efficiency is improved.

  Patent Document 2 discloses another refrigerant recovery device. In this refrigerant recovery device, a heat exchanger in the refrigerant recovery device is used to heat or cool the refrigerant, thereby imparting a fluid force to the refrigerant to facilitate recovery of the refrigerant. Moreover, vaporization of the liquid refrigerant in the apparatus to be collected is promoted by the generated hot gas.

JP 2004-53076 A JP 11-83245 A

  Refrigerant recovery is implemented within the framework of the Freon Recovery and Destruction Law, Home Appliance Recycling Law, and Automobile Recycling Law. However, for example, the refrigerant recovery rate at the time of disposal of refrigeration and air conditioning equipment is only about 30%, and there is a strong recognition that sufficient measures have not been taken. Of course, not only insufficient recovery but also air leakage of refrigerant due to slow leaks during use of the device is regarded as a problem. Government and industry groups are promoting public awareness activities to improve the recovery rate of refrigerants.

  Currently, in order to recover refrigerant from refrigeration and air-conditioning equipment such as commercial refrigeration and air-conditioning equipment typified by multi-air conditioners for buildings, home room air-conditioners, and car air-conditioners, it is common to use commercially available refrigerant recovery equipment. It is. However, in the above-described refrigerant recovery apparatus that sucks and collects refrigerant from the target device as a gas, there is a problem that the work time required for collection becomes extremely long. It is no exaggeration to say that such an adverse effect is one of the factors that hinder the improvement of the refrigerant recovery rate itself.

  Increasing the work time required for refrigerant recovery has been a problem that should be improved for many years in the industry. Although various measures have been taken to improve the efficiency of refrigerant recovery, mainly by refrigerant recovery equipment manufacturers, most of the measures are related to the improvement of refrigerant suction power and condensing capacity. The fact is that no direct measures have been taken.

  In refrigerating and air-conditioning equipment, a gas refrigerant is usually sucked and collected using a commercially available refrigerant recovery device. Since the refrigerant exists in a gas-liquid mixed phase state in the refrigeration air conditioner, the liquid refrigerant is recovered as a gas by vaporization accompanying a pressure drop in the refrigeration air conditioner due to suction. However, the refrigeration cycle (pipe) filled with the refrigerant has a small pipe diameter and a long pipe length. Furthermore, since the structure is complicated, if the suction of the refrigerant is continued, the refrigerant is condensed at a low temperature throughout the cycle, and the liquid refrigerant stagnates in the cycle, making it difficult to collect it as a gas refrigerant. In addition, the refrigerant is dissolved in the compressor oil in the refrigeration air conditioner and is generally present at the bottom of the accumulator in the refrigeration air conditioner, and the dissolved refrigerant separates from the compressor oil and evaporates as the temperature in the cycle decreases. It becomes difficult. Even if the inside of the cycle is sucked to a predetermined pressure, it gradually evaporates after a while. That is, when low-temperature condensation of the refrigerant occurs, the recovery rate of the gas refrigerant rapidly decreases, and the refrigerant recovery amount becomes dull with respect to the recovery time, resulting in a state where it can only be recovered little by little.

  The ministerial ordinance concerning refrigerant recovery stipulates that the pressure at the refrigerant recovery port is suctioned to be equal to or lower than the pressure specified in accordance with the pressure category of the refrigerant after a predetermined time has elapsed. Therefore, in order to reliably recover the refrigerant, the process of slowly sucking in at an appropriate pressure, once reaching a predetermined pressure, stops the recovery, and repeats the process of recovering again while confirming the pressure increase in the cycle. Instructed to do so. However, in this recovery method, since only the reliability of the recovery operation is regarded as important, it is not possible to avoid an increase in the operation time, and the refrigerant is surely recovered over time. In other words, the work efficiency is extremely low against the ease of work itself.

  Patent Document 1 proposes a refrigerant recovery device that promotes vaporization of a low-temperature condensed refrigerant and suppresses a decrease in the refrigerant recovery rate. This refrigerant recovery device has a mode in which the vaporized components of the liquefied and recovered refrigerant are fed back once, and the temperature is increased and increased by a compressor in the refrigerant recovery device and returned to the refrigeration and air conditioning equipment. Yes, it is considered that refrigerant recovery work on site is possible. It is considered that the gas having a calorific value is fed back into the refrigerating and air-conditioning equipment, and this is effective for promoting the vaporization of the refrigerant condensed at low temperature in the equipment. However, this refrigerant recovery device has a structure in which the refrigerant recovery and the vaporization promotion of the refrigerant condensed at low temperature cannot be performed at the same time, and the refrigerant recovery and the vaporization promotion of the refrigerant are alternately performed. Therefore, the working time cannot be shortened as compared with the prior art.

  In Patent Document 2, heating or cooling of a refrigerant to be collected in the refrigerant recovery device gives fluidity to the refrigerant, and makes it easy to convey the refrigerant in one direction in the recovery pipe for easy recovery. It is disclosed. It is also disclosed that the recovery rate is improved by evaporating the condensed refrigerant by using the heated refrigerant as a hot gas. However, Patent Document 2 only shows that the recovery rate is improved by facilitating the flow of the refrigerant, avoiding the low-temperature condensation of the refrigerant, which has been regarded as a problem, in a shorter time than conventional. The idea of completing the collection operation is not included. In addition, a large number of heat exchangers are required in the refrigerant recovery apparatus, and the configuration is extremely complicated. Therefore, it is considered that the refrigerant recovery apparatus is not suitable for on-site recovery work.

  The present invention has been made to solve the above-described problems, and provides a refrigerant recovery system and a refrigerant recovery method that can shorten the refrigerant recovery operation when recovering the refrigerant from the refrigerating and air-conditioning equipment. With the goal.

  The refrigerant recovery system according to the present invention includes a refrigerant recovery path for recovering a gas refrigerant in a refrigeration air conditioner, a carrier gas introduction path for introducing a carrier gas into the refrigeration air conditioner, and a pressure and temperature in the refrigeration air conditioner. A detection unit that detects at least one of the above and a control unit that performs control based on at least one of the pressure and temperature, and the refrigerant recovery path includes a compressor that sucks and compresses the gas refrigerant, and A condenser that condenses the gas refrigerant compressed by the compressor into a liquid refrigerant, and a refrigerant recovery container that recovers the liquid refrigerant condensed by the condenser are provided, and the carrier gas introduction path has A carrier gas supply unit for supplying the carrier gas, and a flow rate adjusting means for adjusting a flow rate of the carrier gas introduced into the refrigeration air conditioner, Control unit, at least one of said pressure and temperature is characterized in that for controlling the flow rate adjusting means so as to be maintained at or above a predetermined value.

  Further, the refrigerant recovery method according to the present invention includes a refrigerant recovery path for recovering a gas refrigerant in the refrigeration air conditioning equipment, a carrier gas introduction path for introducing a carrier gas into the refrigeration air conditioning equipment, and a pressure in the refrigeration air conditioning equipment. And a detecting unit that detects at least one of temperature, and a compressor that sucks and compresses the gas refrigerant in the refrigerant recovery path, and the gas refrigerant compressed by the compressor is condensed into a liquid refrigerant. A condenser for collecting the liquid refrigerant condensed in the condenser, and a carrier gas supply section for supplying the carrier gas to the carrier gas introduction path; A flow rate adjusting means for adjusting the flow rate of the carrier gas introduced into the refrigerating and air-conditioning equipment, and a refrigerant recovery method used in a refrigerant recovery system provided with the pressure and At least one of the time is characterized in introducing said carrier gas into the refrigerating and air-conditioning equipment to be maintained above a predetermined value.

  According to the present invention, when recovering the refrigerant from the refrigerating and air-conditioning equipment, it is possible to suppress the occurrence of low-temperature condensation of the refrigerant in the refrigerating and air-conditioning equipment and prevent a reduction in the recovery speed as a gas refrigerant. Can be shortened.

It is a graph which shows the time change of the refrigerant | coolant collection amount at the time of refrigerant | coolant collection | recovery by the conventional refrigerant | coolant collection | recovery apparatus, and the internal pressure of refrigeration air conditioning equipment. It is a graph which shows the time change of the accumulator bottom part temperature at the time of refrigerant | coolant collection | recovery, and the refrigerating air-conditioning apparatus internal pressure. It is a graph which shows the time change of the refrigerant | coolant collection | recovery amount at the time of refrigerant | coolant collection | recovery by the refrigerant | coolant collection system of this invention, and the pressure in refrigeration air conditioning equipment. It is a system diagram which shows the apparatus structure, control system, flow system, etc. of the refrigerant | coolant collection | recovery system which concern on Embodiment 1 of this invention. It is a system diagram which shows the apparatus structure, control system, flow system, etc. of the refrigerant | coolant collection | recovery system which concern on Embodiment 2 of this invention. It is a system diagram which shows the apparatus structure, control system, flow system, etc. of the refrigerant | coolant collection | recovery system which concern on Embodiment 3 of this invention. It is a systematic diagram which shows the apparatus structure of the refrigerant | coolant collection system which concerns on Embodiment 4 of this invention, a control system, a flow system, etc. It is a systematic diagram which shows the apparatus structure, control system, flow system, etc. of the refrigerant | coolant collection | recovery system which concern on Embodiment 5 of this invention. It is a system diagram which shows the apparatus structure, control system, flow system, etc. of the refrigerant | coolant collection | recovery system which concern on Embodiment 6 of this invention. It is a systematic diagram which shows the structure of the gas separation part 43 of the refrigerant | coolant collection | recovery system which concerns on Embodiment 6 of this invention. It is a system diagram which shows the apparatus structure of the refrigerant | coolant collection system which concerns on Embodiment 7 of this invention, a control system, a flow system, etc. It is a system diagram which shows the apparatus structure, control system, flow system, etc. of the refrigerant | coolant collection | recovery system which concern on Embodiment 8 of this invention. It is a system diagram which shows the apparatus structure of the refrigerant | coolant collection system which concerns on Embodiment 9 of this invention, a control system, a flow system, etc. It is a system diagram which shows the apparatus structure, control system, flow system, etc. of the refrigerant | coolant collection system which concern on Embodiment 10 of this invention. It is a timing chart which shows an example of the time series operation | movement of the pressure in the refrigeration air conditioning apparatus in Embodiment 10 of this invention, and the valve | bulb 106,107,102,103,101 of a refrigerant | coolant collection | recovery system. It is a system diagram which shows the apparatus structure of the refrigerant | coolant collection system which concerns on Embodiment 11 of this invention, a control system, a flow system, etc. It is a systematic diagram which shows the structure of the gas separation part 43 of the refrigerant | coolant collection | recovery system which concerns on Embodiment 12 of this invention. It is a system diagram which shows the apparatus structure of the refrigerant | coolant collection system which concerns on Embodiment 13 of this invention, a control system, a flow system, etc. It is a systematic diagram which shows the apparatus structure, control system, flow system, etc. of the refrigerant | coolant collection system which concern on Embodiment 14 of this invention. It is a system diagram which shows the apparatus structure, control system, flow system, etc. of the refrigerant | coolant collection system which concern on Embodiment 15 of this invention. It is a system diagram which shows the apparatus structure of the refrigerant | coolant collection system which concerns on Embodiment 16 of this invention, a control system, a flow system, etc. It is a systematic diagram which shows the structure of the gas separation part 43 of the refrigerant | coolant recovery system which concerns on Embodiment 16 of this invention. It is a system diagram which shows an example of a structure of the gas separation part 43 of the refrigerant | coolant recovery system which concerns on Embodiment 17 of this invention. It is a systematic diagram which shows the other example of a structure of the gas separation part 43 of the refrigerant | coolant recovery system which concerns on Embodiment 17 of this invention. It is a system diagram which shows the apparatus structure of the refrigerant | coolant collection system which concerns on Embodiment 20 of this invention, a control system, a flow system, etc. FIG.

First, the outline of the present invention will be described in comparison with the prior art.
When the refrigerant in the refrigeration air conditioner is recovered using a conventional refrigerant recovery device, the pressure of the gas-liquid mixed phase refrigerant present in the refrigeration air conditioner decreases with the progress of recovery, and the liquid refrigerant gradually increases. Vaporize. On the other hand, when the refrigerant is vaporized, the amount of heat corresponding to the latent heat of vaporization is taken away from the surroundings, so that the temperature in the refrigeration air conditioner decreases. As the recovery progresses, the pressure and temperature are further reduced, so that the refrigerant mainly dissolved in the compressor oil is prevented from evaporating and is condensed at low temperature (generally referred to as “sleeping”). Recovery as is impossible. That is, the low-temperature condensation of the refrigerant that causes a reduction in the efficiency of the refrigerant gas recovery starts with a pressure drop associated with the recovery operation by the refrigerant recovery device.

  In a commercially available refrigerant recovery apparatus, as an improvement in recovery speed, there are many cases where attention is paid to an improvement in the capacity of a compressor to be mounted and a reduction in pressure loss in a recovery path. However, when the suction force of the refrigerant recovery device is increased or the pressure loss in the recovery path is reduced, the amount of gas refrigerant recovered per hour at the beginning of the refrigerant recovery operation can be increased. The pressure drop only occurs earlier in the recovery, and the low temperature condensation of the refrigerant itself cannot be avoided. That is, in the second half of the refrigerant recovery operation in which low temperature condensation of the refrigerant occurs, the amount of gas refrigerant recovered per hour cannot be increased, and thus the recovery speed cannot be increased. Therefore, as long as the conventional refrigerant recovery method of recovering the refrigerant in the refrigeration air conditioner by suction of the refrigerant recovery device is adopted, the longer recovery time becomes an unavoidable event.

  FIG. 1 is a graph showing temporal changes in refrigerant recovery amount and refrigeration and air-conditioning equipment internal pressure (pressure at the refrigerant recovery port) during refrigerant recovery by a conventional refrigerant recovery apparatus. In the figure, the vertical axis represents the refrigerant recovery amount and the internal pressure of the refrigeration and air conditioning equipment, and the horizontal axis represents the recovery time. As shown in FIG. 1, at the initial stage (points A to B in the figure) of the conventional refrigerant recovery operation, the refrigerant recovery amount increases substantially linearly with respect to the recovery time, and the pressure increases substantially linearly. It is falling. The inclinations of these straight lines indicate the refrigerant recovery speed that is substantially determined by the conductance of the flow path of the refrigeration air conditioner and the refrigerant recovery apparatus and the capacity of the compressor of the refrigerant recovery apparatus. The fact that the refrigerant recovery amount and the pressure change linearly indicates an ideal recovery state in which there are no other obstacles to refrigerant recovery. Therefore, if all the steps of refrigerant recovery can be performed at this recovery speed, the recovery ends at point B 'in the figure. In this case, by increasing the refrigerant suction capability of the compressor, the recovery speed increases, the gradient of increase in the recovery amount and the pressure decrease becomes larger, and it is conceivable that the recovery ends before the point B ′.

  However, in practice, collection does not end at point B '. In the latter period of recovery (after point B), changes in the refrigerant recovery amount and the pressure in the refrigeration air conditioner start to slow down with respect to the recovery time, and change gradually. That is, after point B, the amount of gas refrigerant recovered per hour is extremely small, and the recovery operation is stagnant, and it takes a lot of time to reach point C, which is the actual end point of recovery. This is due to the fact that the vaporization of the liquid refrigerant in the circuit is promoted by the pressure in the refrigeration air-conditioning equipment being lowered. The vaporization of the liquid refrigerant itself is a very advantageous event in gas refrigerant recovery. However, since the refrigerant takes away the amount of heat around it when vaporized, the temperature in the circuit decreases. That is, the phenomenon after the point B in FIG. 1 is a state where the presence of the gas refrigerant is restricted in a state below a certain pressure, in other words, the remaining refrigerant is condensed at a low temperature to become a liquid refrigerant, and recovery by the gas refrigerant is not possible. Indicates impossible. That is, as long as refrigerant recovery is performed using a conventional refrigerant recovery device that causes such a change in refrigerant state, a decrease in the recovery rate in the late recovery period is an unavoidable event. Moreover, even if the capacity of the compressor is improved, only the recovery speed at the initial stage of recovery is improved, and it is impossible to shorten the entire recovery process. In the conventional recovery method, it can also be seen that it is difficult to recover the entire amount of refrigerant due to the stagnation of the recovery operation even at point C, which is the end point of recovery.

  FIG. 2 is a graph showing temporal changes in accumulator bottom temperature and refrigeration air conditioning equipment pressure during refrigerant recovery. In the figure, the vertical axis represents the accumulator bottom temperature and the pressure inside the refrigeration air conditioning equipment, and the horizontal axis represents the recovery time. It is known that the low-temperature condensation of the refrigerant accompanying the refrigerant recovery operation mainly occurs at the bottom of the accumulator. As shown in FIG. 2, it can be seen that the temperature at the bottom of the accumulator shows almost the same change as the pressure in the refrigerating and air-conditioning equipment. A decrease in the temperature at the bottom of the accumulator indicates that low-temperature condensed refrigerant accumulates, and when the pressure change in the refrigeration air conditioning equipment decreases, the change in the temperature at the bottom of the accumulator is low, even if the absolute value is low. The amount is getting smaller. Furthermore, since the pressure change in the refrigeration air conditioner is reduced immediately before the end of the recovery, the temperature at the bottom of the accumulator does not decrease any more, but rather tends to increase under the influence of outside air. That is, the low-temperature condensation of the refrigerant can be confirmed not only by the pressure in the refrigerating and air-conditioning equipment but also by the temperature drop at the bottom of the accumulator.

  FIG. 3 is a graph showing temporal changes in the refrigerant recovery amount and the pressure in the refrigeration / air conditioning equipment during refrigerant recovery by the refrigerant recovery system of the present invention. In the figure, the vertical axis represents the refrigerant recovery amount and the internal pressure of the refrigeration and air conditioning equipment, and the horizontal axis represents the recovery time. FIG. 3 also shows temporal changes in the refrigerant recovery amount and the pressure in the refrigeration air-conditioning equipment when the refrigerant is recovered by the conventional refrigerant recovery apparatus.

  In the refrigerant recovery system of the present invention, carrier gas is introduced from the outside into the refrigeration air conditioner before the low temperature condensation of the refrigerant becomes significant, and at least one of the pressure and temperature in the refrigeration air conditioner is maintained at a predetermined value or more. To be controlled. As a result, as shown in FIG. 3, the pressure (and temperature) in the refrigeration air-conditioning equipment is not extremely reduced, and the low-temperature condensation of the refrigerant in the refrigeration air-conditioning equipment is suppressed. Therefore, throughout the entire recovery process, the recovery of the refrigerant in the gas state is smoothly performed, and the low-temperature condensation of the refrigerant and the refrigerant recovery operation are performed simultaneously (in parallel). In addition, in FIG. 3, the case where it controls so that the pressure in refrigeration air-conditioning equipment may become fixed with the pressure just before low-temperature condensation of a refrigerant | coolant becomes remarkable is illustrated. Refrigerant recovery by the refrigerant recovery system of the present invention ends at point D earlier than that at which the refrigerant recovery by the conventional refrigerant recovery device ends at point C. Therefore, according to the refrigerant recovery system of the present invention, the refrigerant recovery can be completed in a short time. Further, according to the refrigerant recovery system of the present invention, the recovery operation can be completed in a short time, so that the amount of refrigerant recovered can be approached as much as the total amount recovery.

  In the refrigerant recovery system, at least one of the pressure and temperature in the refrigeration air conditioner is monitored so that the refrigerant in the refrigeration air conditioner does not cause low-temperature condensation, and the refrigeration is performed so that the value maintains a predetermined value or more. A carrier gas supply unit that introduces carrier gas from the outside of the air conditioner is provided. Therefore, the stagnation of the liquid refrigerant, which is the cause of the reduction in the recovery speed, is suppressed in the refrigeration and air-conditioning equipment, and the recovery speed of the gas refrigerant can be improved as compared with the conventional refrigerant recovery apparatus in the late recovery period. Refrigerant recovery and suppression of stagnation refrigerant can be performed at the same time. As a result, it is possible to reduce the time required for refrigerant recovery, which has been a long-standing problem.

  In the refrigerant recovery system according to the present invention, the switching from the first refrigerant recovery path to the second refrigerant recovery path is performed before the low-temperature condensation of the refrigerant becomes significant. Subsequently, the carrier gas is introduced from the outside of the refrigeration / air conditioning equipment so that at least one of the pressure and temperature in the refrigeration / air conditioning equipment is maintained at a predetermined value or higher, and is mixed with the remaining refrigerant. Furthermore, the gas separation unit provided in the second refrigerant recovery path can selectively separate and recover the refrigerant component from the mixed gas of the carrier gas and the gas refrigerant. Therefore, the pressure and temperature in the refrigeration air conditioner will not be extremely reduced. Therefore, the stagnation of the liquid refrigerant in the refrigeration air conditioner is suppressed, and the refrigerant is smoothly collected in the gas state. Further, the refrigerant stagnation suppression and the refrigerant recovery operation are performed simultaneously.

  In the refrigerant recovery system, at least one of the pressure and temperature in the refrigeration air conditioner is monitored so that the refrigerant in the refrigeration air conditioner does not cause low temperature condensation, and the value is maintained at a predetermined value or more. Select a collection route. Furthermore, it has a carrier gas supply part which introduces carrier gas from the outside of the refrigerating and air-conditioning equipment, and has a gas separation part which selectively separates the refrigerant from the mixed gas. Therefore, the stagnation of the liquid refrigerant, which is the cause of the reduction in the recovery speed, is suppressed in the refrigeration and air-conditioning equipment, and the recovery speed of the gas refrigerant can be improved as compared with the conventional refrigerant recovery apparatus in the late recovery period. Refrigerant recovery and suppression of stagnation refrigerant can be performed at the same time. As a result, it is possible to reduce the time required for refrigerant recovery, which has been a long-standing problem.

  In the refrigerant recovery system of the present invention, the refrigerant concentration is reduced using the bypass path before recovery, and then the switching to the refrigerant recovery path is performed. Subsequently, a carrier gas is introduced from the outside of the refrigeration and air conditioning equipment so that at least one of the pressure and temperature in the refrigeration and air conditioning equipment is maintained at a predetermined value or more, mixed with the remaining refrigerant, and the refrigerant is further reduced in concentration. Is done. That is, it can respond to a slightly flammable or flammable refrigerant. Furthermore, the refrigerant component can be selectively separated and recovered from the mixed gas of the carrier gas and the gas refrigerant by the gas separation unit provided in the refrigerant recovery path. Therefore, the pressure and temperature in the refrigeration air conditioner will not be extremely reduced. Therefore, the stagnation of the liquid refrigerant in the refrigeration air conditioner is suppressed, and the refrigerant is smoothly collected in the gas state. Further, the refrigerant stagnation suppression and the refrigerant recovery operation are performed simultaneously.

  In the refrigerant recovery system, a carrier gas supply unit that monitors at least one of the pressure and temperature in the refrigeration air conditioner and introduces a carrier gas from the outside of the refrigeration air conditioner so that the value maintains a predetermined value or more. Have. After reducing the concentration of the refrigerant using the bypass path before recovery, switch to the refrigerant recovery path, and the pressure and temperature in the refrigeration air conditioning equipment will not cause low temperature condensation in the refrigeration air conditioning equipment. At least one of these is monitored, and the introduction of the carrier gas from the outside of the refrigeration / air-conditioning equipment is continued so that the value is maintained at a predetermined value or more. Therefore, the stagnation of the liquid refrigerant, which is the cause of the reduction in the recovery speed, is suppressed in the refrigeration and air-conditioning equipment, and the recovery speed of the gas refrigerant can be improved as compared with the conventional refrigerant recovery apparatus in the late recovery period. Refrigerant recovery and suppression of stagnation refrigerant can be performed at the same time. As a result, it is possible to reduce the time required for refrigerant recovery, which has been a long-standing problem.

  Further, in the refrigerant recovery method of the present invention, by monitoring at least one of the pressure and temperature in the refrigeration air conditioning equipment, the pressure or temperature is compared with a predetermined value, and the carrier gas is introduced into the refrigeration air conditioning equipment. Make it work. In the initial stage of refrigerant recovery, a normal recovery mode, which is the same recovery method as before, is performed, and in the latter stage of refrigerant recovery, a separation recovery mode in which carrier gas is introduced into the refrigeration air conditioner is performed. By continuously performing the refrigerant recovery in the normal recovery mode and the refrigerant recovery in the separation recovery mode, an extreme decrease in pressure and temperature in the refrigeration air conditioner is avoided. Therefore, the stagnation of the liquid refrigerant in the refrigeration air conditioner is suppressed, and the refrigerant is smoothly collected in the gas state. Further, the refrigerant stagnation suppression and the refrigerant recovery operation are performed simultaneously.

  In the above refrigerant recovery method, the initial refrigerant recovery method is substantially the same as the conventional refrigerant recovery method, but at least one of the pressure and temperature in the refrigeration air conditioner is set so that the refrigerant in the refrigeration air conditioner does not cause low temperature condensation. Monitor and shift to the separation and recovery mode in which the carrier gas is introduced from the outside of the refrigerating and air-conditioning equipment so that the value is maintained above the predetermined value. Therefore, the stagnation of the liquid refrigerant, which is the cause of the decrease in the recovery speed, is suppressed in the refrigeration and air conditioning equipment, and the recovery speed of the gas refrigerant can be improved as compared with the conventional refrigerant recovery apparatus. Refrigerant recovery and suppression of stagnation refrigerant can be performed at the same time. As a result, it is possible to reduce the time required for refrigerant recovery, which has been a long-standing problem.

  In the refrigerant recovery method according to the present invention, at least one of the pressure and temperature in the refrigeration air-conditioning equipment is monitored, and the pressure or temperature is compared with a predetermined value, and the refrigerant recovery path is switched. In the initial stage of refrigerant recovery, the normal recovery mode using the first refrigerant recovery path is performed, and in the latter stage of refrigerant recovery, the second refrigerant recovery path and the separation recovery mode using the carrier gas are performed. By continuously performing the refrigerant recovery in the normal recovery mode and the refrigerant recovery in the separation recovery mode, an extreme decrease in pressure and temperature in the refrigeration air conditioner is avoided. Therefore, the stagnation of the liquid refrigerant in the refrigeration air conditioner is suppressed, and the refrigerant is smoothly collected in the gas state. Further, the refrigerant stagnation suppression and the refrigerant recovery operation are performed simultaneously.

  In the above refrigerant recovery method, the initial stage of refrigerant recovery is the normal recovery mode using the first refrigerant recovery path that is almost the same as the conventional one, but in the refrigeration air conditioning equipment, the refrigerant in the refrigeration air conditioning equipment does not generate low-temperature condensation. Separation and recovery mode in which at least one of the pressure and temperature is monitored, the refrigerant recovery path is shifted to the second refrigerant recovery path, and the carrier gas is introduced from the outside of the refrigeration air conditioner so that the value is maintained at a predetermined value or more Migrate to Therefore, the stagnation of the liquid refrigerant, which is the cause of the decrease in the recovery speed, is suppressed in the refrigeration and air conditioning equipment, and the recovery speed of the gas refrigerant can be improved as compared with the conventional refrigerant recovery apparatus. Refrigerant recovery and suppression of stagnation refrigerant can be performed at the same time. As a result, it is possible to reduce the time required for refrigerant recovery, which has been a long-standing problem.

  Further, in the refrigerant recovery method according to the present invention, before recovery, at least one of the pressure and temperature of the refrigeration air-conditioning equipment is monitored using a bypass path, and the carrier gas is refrigerated and air-conditioned by comparing the pressure or temperature with a predetermined value. Operate to be introduced into equipment. In addition, the concentration of the slightly flammable or flammable refrigerant that is the target refrigerant is reduced. Refrigerant recovery is performed by continuously collecting the refrigerant in the separation and recovery mode in which the carrier gas is introduced into the refrigeration air conditioner, thereby reducing the pressure and temperature in the refrigeration air conditioner while reducing the concentration of the refrigerant. To avoid. Therefore, the stagnation of the liquid refrigerant in the refrigeration air conditioner is suppressed, and the refrigerant is smoothly collected in the gas state. Further, the refrigerant stagnation suppression and the refrigerant recovery operation are performed simultaneously.

  In the refrigerant recovery method, before the refrigerant is recovered, the bypass mode in which the carrier gas is introduced from the outside of the refrigerating and air-conditioning equipment to reduce the concentration of the refrigerant to be recovered is performed, and the refrigerant is reduced when the refrigerant concentration becomes a predetermined concentration or less. Switch the collection path and switch to the separation collection mode. In the separation / recovery mode, at least one of the pressure and temperature in the refrigeration / air conditioning equipment is monitored so that the refrigerant in the refrigeration / air conditioning equipment does not cause low-temperature condensation, and the value is maintained above a predetermined value by introducing carrier gas. To do. Therefore, the stagnation of the liquid refrigerant, which is the cause of the decrease in the recovery speed, is suppressed in the refrigeration and air conditioning equipment, and the recovery speed of the gas refrigerant can be improved as compared with the conventional refrigerant recovery apparatus. Refrigerant recovery and suppression of stagnation refrigerant can be performed at the same time. As a result, it is possible to reduce the time required for refrigerant recovery, which has been a long-standing problem.

  Hereinafter, each embodiment of the present invention will be described.

Embodiment 1 FIG.
A refrigerant recovery system and a refrigerant recovery method according to Embodiment 1 of the present invention will be described. FIG. 4 is a system diagram showing a device configuration, a control system, a flow system, and the like of the refrigerant recovery system according to the present embodiment. In the figure, a solid line indicates a pipe through which a fluid flows, and a broken line indicates a part of an input / output control line through the control unit 11.

  First, the configuration of the refrigerant recovery system according to the present embodiment will be described. Here, a multi air conditioning system for buildings will be described as an example of a refrigeration air conditioner that is a target for refrigerant recovery. Needless to say, this embodiment and each of the following embodiments can be applied not only to the building multi-air conditioner but also to the recovery of refrigerants for all devices that use refrigerant.

  As shown in FIG. 4, the building multi-air conditioner for which refrigerant is to be collected has an indoor unit 1 and an outdoor unit 2. The outdoor unit 2 includes a compressor 22, a four-way valve 20, an outdoor heat exchanger 23, and an accumulator 21. The indoor unit 1 includes an expansion device (not shown) and an indoor heat exchanger. The compressor 22, the four-way valve 20, the outdoor heat exchanger 23, the expansion device, the indoor heat exchanger, and the accumulator 21 constitute a refrigeration cycle. The outdoor unit 2 and the indoor unit 1 are connected by, for example, two refrigerant pipes (gas pipe and liquid pipe). Note that the expansion device may be provided in the outdoor unit 2.

  The refrigerant recovery system in the present embodiment includes a manifold 3, a refrigerant recovery unit 4, a pressure detection unit 5, a refrigerant concentration detection unit 6, a leak concentration detection unit 7, a carrier gas supply unit 8, a flow rate adjustment unit 9, and a carrier gas. An introduction pipe 10, a control unit 11, and valves 100 and 101 are provided. The refrigerant recovery unit 4 includes a compressor 40, a condenser 41, and a refrigerant recovery container 42.

  In addition, the refrigerant recovery system in the present embodiment includes a refrigerant recovery path 500, a non-condensed gas discharge path 501 and a carrier gas introduction path 502 (carrier gas introduction pipe 10). The refrigerant recovery path 500 is for recovering the refrigerant in the building multi-air conditioner and filling the refrigerant recovery container 42. In the refrigerant recovery path 500, the manifold 3, the pressure detection unit 5, the refrigerant concentration detection unit 6, the valve 100, the compressor 40, the condenser 41, and the refrigerant recovery container 42 are provided in this order in the flow direction during refrigerant recovery. ing. The non-condensed gas discharge path 501 is for discharging the non-condensed gas in the refrigerant recovery container 42 to the outside. The non-condensed gas discharge path 501 is provided with the refrigerant recovery container 42, the leak concentration detector 7 and the valve 104 in this order in the flow direction when discharging the non-condensed gas. The carrier gas introduction path 502 is for introducing the carrier gas into the building multi-air conditioner. In the carrier gas introduction path 502, a carrier gas supply unit 8, a flow rate adjustment unit 9, and a valve 101 are provided in this order in the flow direction when introducing the carrier gas. Here, the flow rate adjusting unit 9 and the valve 101 constitute flow rate adjusting means for adjusting the flow rate of the carrier gas supplied from the carrier gas supply unit 8 and introduced into the building multi-air conditioner.

  The control unit 11 is a microcomputer including a CPU, a ROM, a RAM, and an input / output port. Based on detection signals output from various sensors (for example, the pressure detection unit 5, the refrigerant concentration detection unit 6, the leak concentration detection unit 7, etc.), the control unit 11 performs various devices (for example, a compressor) in the refrigerant recovery system. 40, valves 100, 101, 104, a refrigerant inlet valve 420, a non-condensable gas outlet valve 421, etc., which will be described later).

  When implementing refrigerant recovery, shut off the power supply of the building multi-air conditioner so that it is not energized during recovery. This is from the viewpoint of ensuring safety during work. In general, from the viewpoint of improving the efficiency of collection work, it is necessary to pump down without shutting off the power supply of the building multi-air conditioner and collect the refrigerant to be collected on the outdoor unit side before collection. It is carried out as work. However, since the refrigerant in the building multi-air conditioner is in a gas-liquid mixed phase state, the liquid refrigerant is introduced into the compressor 22 in the building multi-air conditioner in the recovery operation while operating the pump down or the building multi-air conditioner. Liquid compression occurs. Liquid compression is an overload state in the compressor 22 and often leads to failure such as seizure. Further, from the viewpoint of improving the efficiency of the recovery work, liquid refrigerant may be recovered in advance by inserting piercing into the piping in the building multi-air conditioner. However, it is not realistic in consideration of piping processing and subsequent use. Therefore, in the present embodiment and each of the following embodiments, it is assumed that the building multi-air conditioner is de-energized and that the recovery operation is performed in a state where pump down or liquid refrigerant recovery is not performed.

  A multi air conditioner for buildings is usually provided with a high pressure side (liquid side) service port 200 and a low pressure side (gas side) service port 201. In this example, the high-pressure side service port 200 is provided in the high-pressure pipe between the compressor in the outdoor unit 2 and the four-way valve, and the low-pressure side service port 201 is between the four-way valve in the outdoor unit 2 and the accumulator. Of low pressure piping. The refrigerant recovery operation is generally performed through the high-pressure side service port 200 and the low-pressure side service port 201. Similarly, in the present embodiment, the manifold 3 is connected to each of the high-pressure side service port 200 and the low-pressure side service port 201, and the output of the manifold 3 is passed through the pressure detection unit 5 and the refrigerant concentration detection unit 6. Connected to the refrigerant recovery unit 4. Thereby, the multi air conditioning system for buildings and the refrigerant recovery unit 4 are connected via the refrigerant recovery path.

  A carrier gas supply unit 8 is connected to the building multi-air conditioner via a carrier gas introduction pipe 10, a valve 101, and a flow rate control unit 9. In the configuration of this example, the leading end side of the carrier gas introduction pipe 10 is bifurcated, and the two branched tip portions are respectively a gas pipe and a liquid pipe connecting the indoor unit 1 and the outdoor unit 2. Connected to.

  Next, the refrigerant recovery operation in the present embodiment will be described. Details of the configuration of the refrigerant recovery system will also be described. First, the power supply of the building multi-air conditioner is shut off, and the high-pressure side service port 200 and the low-pressure side service port 201 are connected to the refrigerant recovery unit 4 via the refrigerant recovery path. The refrigerant recovery unit 4 includes a compressor 40, a condenser 41, and a refrigerant recovery container 42. The gas refrigerant sucked from the building multi-air conditioner is heated to a high temperature and a high pressure by the compressor 40, is liquefied and condensed in the condenser 41, and is recovered in the refrigerant recovery container 42 as a liquid refrigerant.

  The refrigerant recovery container 42 is provided with a refrigerant inlet valve 420 and a non-condensed gas outlet valve 421. The refrigerant inlet valve 420 is provided in the middle of a refrigerant introduction pipe (a part of the refrigerant recovery path) from the condenser 41 to the bottom of the refrigerant recovery container 42. By providing the refrigerant introduction pipe to the bottom of the refrigerant recovery container 42, the liquid refrigerant flowing from the condenser 41 is filled from the bottom of the refrigerant recovery container 42. The non-condensed gas outlet valve 421 is provided in the middle of a non-condensed gas outlet pipe that connects the upper part of the refrigerant recovery container 42 and the outside via the leak concentration detector 7. The refrigerant recovery container 42 is previously evacuated to about -0.1 MPa (gauge pressure). Further, in the refrigerant recovery container 42, particularly when the collection target is a mixed refrigerant such as R410A and R407C, low-boiling R32, which is a component of the mixed refrigerant, is collected at a high concentration at the beginning of the collection. For this reason, the pressure in the refrigerant recovery container 42 may increase rapidly, and the recovery speed may be significantly reduced. Therefore, in order to suppress the vaporization of the recovered refrigerant and suppress the increase in the internal pressure of the refrigerant recovery container 42, it is better to allow the outer surface to be cooled and to suppress the temperature increase. Further, the pressure in the refrigerant recovery container 42 may be adjusted by appropriately opening the non-condensed gas outlet valve 421 according to the pressure in the refrigerant recovery container 42.

  As described above, the refrigerant recovery mode in which the gas refrigerant sucked from the building multi-air conditioner is recovered as the liquid refrigerant in the refrigerant recovery container 42 through the compressor 40 and the condenser 41 is referred to as “normal recovery mode”. In the normal recovery mode, the valve 100 and the refrigerant inlet valve 420 are in an open state, the valve 101 is in a closed state, and the non-condensed gas outlet valve 421 is in a closed state in principle. That is, in the normal recovery mode, the gas refrigerant in the building multi-air conditioner is recovered without introducing the carrier gas.

  As the refrigerant recovery in the normal recovery mode proceeds, the amount of refrigerant remaining in the building multi-air conditioner decreases, so the pressure in the building multi-air conditioner gradually decreases. The pressure in the multi air conditioner in the building is detected by the pressure detector 5, and in the present embodiment, the pressure value is maintained in the system so as to be maintained at a predetermined value or higher. Be controlled. That is, the pressure detection unit 5 is configured to issue an output signal to the control unit 11 when the pressure once falls below a predetermined value. The control unit 11 performs control to change the refrigerant recovery mode of the refrigerant recovery system from the normal recovery mode to a separation recovery mode to be described later in accordance with the input signal. Note that the pressure detection unit 5 may be configured to output a detected pressure signal to the control unit 11 at any time, and the control unit 11 side determines whether or not the detected pressure falls below a predetermined value. Of course. The transition to the refrigerant recovery mode is basically irreversible, and the transition from the normal recovery mode to the separation / recovery mode is made, but the transition from the separation / recovery mode to the normal recovery mode is not basically performed. Further, as the trigger for changing the refrigerant recovery mode, in addition to the determination based on the pressure value described above, the time change of the pressure, that is, the slope of the pressure curve shown in FIG. 3 may be used.

  When receiving the output signal from the pressure detection unit 5, the control unit 11 opens the valve 101 and supplies the carrier gas supplied from the carrier gas supply unit 8 via the flow rate adjustment unit 9 and the carrier gas introduction pipe 10. To be introduced into the multi air conditioner for use. At the same time, the control unit 11 opens the non-condensed gas outlet valve 421 of the refrigerant recovery container 42. The control unit 11 adjusts the pressure in the building multi-air conditioner according to the opening degree of the valve 100 and the flow rate of the carrier gas defined by the flow rate adjusting unit 9. Furthermore, the control part 11 implements rotation speed control of the compressor 40 and opening degree adjustment of the non-condensable gas outlet valve 421 as needed. In this refrigerant recovery mode, the carrier gas is introduced into the building multi-air conditioner so that the remaining refrigerant is a mixed gas of the refrigerant and the carrier gas (hereinafter sometimes referred to as “refrigerant mixed gas”). Further, the refrigerant mixed gas maintains the pressure in the building multi-air conditioner at a predetermined value or higher. That is, the refrigerant mixed gas is recovered to the refrigerant recovery unit 4 by forming a pressure space that suppresses the low-temperature condensation of the remaining refrigerant without reducing the pressure in the building multi-air conditioner more than necessary.

  As described above, the refrigerant recovery mode for recovering the gas refrigerant while controlling the pressure (or temperature) in the building multi-air conditioner by introducing the carrier gas is referred to as “separation recovery mode”. In this example, the carrier gas introduction pipe 10 is connected to both the gas pipe and the liquid pipe of the building multi-air conditioner, but may be connected to either the gas pipe or the liquid pipe. Further, in the outdoor unit 2, a four-way valve 20 that changes the fluid flow between the cooling operation and the heating operation of the building multi-air conditioner (the refrigerant flow path in the air conditioner between the cooling operation and the heating operation). To change the valve). This four-way valve is preferably configured to be able to operate independently during manual operation or by an external power source other than the building multi-air conditioner during the refrigerant recovery operation, and may be appropriately switched during the separation and recovery mode. By this switching operation, the carrier gas reaches every part in the multi air conditioner for buildings.

  As the carrier gas, an inert gas is used, and for example, nitrogen, argon, or helium is used. Since air contains oxygen which is a combustion-supporting component, use as a carrier gas is not preferable. The non-condensable gas indicates a mixed gas of a vaporized component of the refrigerant stored as a liquid refrigerant and a carrier gas component that is not condensed in the refrigerant mixed gas. The vaporized component of the refrigerant recovered in the refrigerant recovery container 42 can be reduced by controlling the temperature of the refrigerant recovery container 42 and appropriately cooling the refrigerant recovery container 42. The carrier gas supply unit 8 is installed outside the building multi-air conditioner, and may be a gas generation facility for generating the carrier gas or a general high-pressure gas cylinder.

  In the separation and recovery mode, as described above, since the carrier gas is introduced into the building multi-air conditioner, the remaining refrigerant in the building multi-air conditioner becomes a mixed gas with the carrier gas. That is, the gas to be collected becomes a refrigerant mixed gas that is diluted with the carrier gas and has a reduced concentration. The refrigerant mixed gas is sucked and compressed by the compressor 40 and introduced into the condenser 41. The refrigerant mixed gas introduced into the condenser 41 acts so that only the refrigerant component is condensed and the carrier gas component is not condensed. That is, among the refrigerant mixed gas introduced from the refrigerant inlet valve 420, only the refrigerant component is stored in the refrigerant recovery container 42 in a liquid state, and the other components (mainly carrier gas components) are not condensed as gas. The gas is discharged from the gas recovery valve 42 through the gas outlet valve 421. In the separation and recovery mode, as the recovery proceeds, the gas composition in the building multi-air conditioner becomes richer in the carrier gas component. For this reason, as the recovery time elapses, the concentration of the refrigerant introduced into the refrigerant recovery unit 4 tends to decrease, and the non-condensed gas flow rate tends to increase.

  Further, the pressure in the building multi-air conditioner set as the predetermined value in the separation / recovery mode only needs to be higher than the pressure at which low temperature condensation is conventionally generated. Conventionally, the recovery reference pressure is set to −0.01 MPa (gauge pressure) or less, but suction is performed until it becomes substantially −0.1 MPa (gauge pressure). For this reason, low-temperature condensation of the refrigerant has occurred. In the present embodiment, for example, the low-temperature condensation of the refrigerant can be suppressed by maintaining the pressure in the building multi-air conditioner at least at a pressure that does not become negative, that is, a pressure equal to or higher than atmospheric pressure. However, if the pressure in the building multi-air conditioner is set too high, the operation of the compressor 40 is burdened. Therefore, the upper limit value of the pressure needs to be set to a value according to the capacity of the compressor 40.

  In the recovery of the refrigerant, the initial charge amount of the building multi-air conditioner is compared with the weight of the refrigerant recovered in the refrigerant recovery container 42, and the recovery is performed when the recovered weight reaches at least 90% of the initial charge amount. It is common to end. This is carried out by measuring the weight of the refrigerant recovery container 42. Also in the present embodiment, since the recovery of the refrigerant is performed in the refrigerant recovery container 42, the end of the recovery operation may be determined based on the recovered weight in the same manner as described above.

  In addition to weight management, a recovery reference pressure (suction pressure at the refrigerant recovery port) is set for each type of refrigerant as a guideline for a recovery amount (so-called recovery rate) with respect to the refrigerant charging amount to be 90% or more. In some cases, the end of recovery is determined by the refrigerant suction pressure. For example, a refrigerant (R410A, R407C, R22, etc.) corresponding to a high-pressure gas that fills the refrigerating and air-conditioning equipment with 2 kg or more needs to be sucked until it becomes −0.01 MPa (gauge pressure) or less. However, as described above, the actual situation is that suction is performed to −0.1 MPa (gauge pressure) or less. However, in this embodiment, in order to maintain the pressure in the building multi-air conditioner at a high pressure that does not cause a decrease in the suction pressure that causes the low-temperature condensation of the refrigerant, for example, a pressure higher than the atmospheric pressure, the above guidelines The end of recovery cannot be determined based on the recovery reference pressure shown in.

In the present embodiment, the refrigerant concentration detector 6 detects the refrigerant concentration in the building multi-air conditioner. From the refrigerant concentration detector 6, a refrigerant concentration detection signal is output to the controller 11. Thereby, in the control part 11, the completion | finish determination of collection | recovery can be performed with a residual refrigerant | coolant density | concentration or a residual refrigerant | coolant amount. In this end determination, a collection operation with higher accuracy than conventional can be expected. When the refrigerant concentration is used for the end determination, the residual refrigerant concentration is equal to or less than the refrigerant atmospheric emission limit (for example, 0.30 kg / m ^{3 in} the case of R410A or R407C), and the remaining refrigerant amount is used for the end determination. For example, it is possible to easily realize a stricter end determination than the conventional case where the remaining refrigerant amount is 1% or less of the initial refrigerant charging amount (the recovery rate is 99% or more). In conventional collection work, the above-described high-accuracy collection was impossible in practice due to the lengthening of the work time, but by realizing the shortening of the collection work according to the present embodiment, Realization of a high recovery rate that suppresses the amount of refrigerant released to the atmosphere as much as possible is also expected.

  In addition, it is conceivable that the non-condensable gas discharged from the non-condensable gas outlet valve 421 is slightly mixed with the refrigerant component to be collected. In this case, an adsorbent such as activated carbon is disposed downstream of the leak concentration detection unit 7 so that a slightly mixed refrigerant is adsorbed and removed so as not to be released into the atmosphere.

  As described above, in the present embodiment, when the refrigerant is sucked and collected from the refrigeration air conditioner, the carrier gas is introduced from the outside of the refrigeration air conditioner so that the pressure in the refrigeration air conditioner becomes a predetermined value or more. Control. In addition, based on the pressure in the refrigeration and air-conditioning equipment, the refrigerant recovery mode is basically based on the normal recovery mode, which is almost the same as before, and the separation recovery mode, in which the pressure is controlled by introducing carrier gas, in the latter stage of recovery. Switch irreversibly. As a result, it is possible to suppress the low-temperature condensation of the refrigerant that has occurred in the second half of the refrigerant recovery operation and to suppress a decrease in the recovery rate of the gas refrigerant. Therefore, it is possible to reduce the time for collecting the refrigerant compared to the conventional case. In addition, the refrigerant recovery mode can be shifted continuously, and the recovery of the refrigerant and the promotion of vaporization of the remaining refrigerant can be performed simultaneously. Therefore, it is possible to achieve a significantly shortened time for refrigerant recovery work as compared with the prior art. Furthermore, the determination of the end of recovery is not limited to the conventional determination based on the recovery weight of the refrigerant, but also the determination based on the refrigerant concentration or the amount of refrigerant that is the target of recovery. This can be realized and the amount of refrigerant leakage to the atmosphere can be suppressed as much as possible.

Embodiment 2. FIG.
A refrigerant recovery system and a refrigerant recovery method according to Embodiment 2 of the present invention will be described. FIG. 5 is a system diagram showing a device configuration, a control system, a flow system, and the like of the refrigerant recovery system according to the present embodiment. In addition, about the component which has the function and effect | action same as Embodiment 1, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  The refrigerant recovery system according to the present embodiment has substantially the same configuration as that of the first embodiment and operates in substantially the same manner, but mainly the gas flow from the non-condensed gas outlet valve 421 in the refrigerant recovery container 42. The difference is that the path merges with the carrier gas introduction pipe 10 via the circulation pump 12. That is, this embodiment is characterized in that the non-condensed gas and the carrier gas are circulated through the building multi-air conditioner and the refrigerant recovery unit 4 and recycled. Specifically, in the non-condensed gas discharge path 501 through which the exhaust gas from the refrigerant recovery container 42 circulates, the branch part 300 provided between the leak concentration detector 7 and the valve 104, and the carrier gas introduction pipe 10. A container exhaust gas recirculation path 503 is provided to connect between the merging section 301 provided on the downstream side (tip end side) of the valve 101 in the (carrier gas introduction path 502). The container exhaust gas recirculation path 503 is provided with a circulation pump 12 and a valve 105 located on the upstream side (branch unit 300 side) of the circulation pump 12. A valve 102 and a flow rate sensor 13 are provided in this order on the downstream side of the junction 301 in the carrier gas introduction pipe 10. A mixed gas discharge path 504 is branched from the junction 301 of the carrier gas introduction pipe 10. A valve 103 is provided in the mixed gas discharge path 504.

  In the normal recovery mode, the valve 100 and the refrigerant inlet valve 420 are open, the valves 101, 102, 103, 105 are closed, the non-condensed gas outlet valve 421 and the valve 104 are in principle fully closed, and the circulation pump 12 is stopped. State. During refrigerant recovery in the normal recovery mode, the pressure in the building multi-air conditioner detected by the pressure detection unit 5 is maintained at a predetermined value or higher. That is, in the normal recovery mode, the pressure detection unit 5 is configured to issue an output signal to the control unit 11 when the pressure once falls below a predetermined value. The control unit 11 performs control to change the refrigerant recovery mode from the normal recovery mode to the separation recovery mode according to the output signal. In the normal recovery mode, the non-condensed gas outlet valve 421 and the valve 104 may be appropriately opened and closed in order to avoid an increase in the pressure of the refrigerant recovery container 42.

  When receiving the output signal from the pressure detection unit 5, the control unit 11 performs the transition to the separation and recovery mode. In the separation and recovery mode, the valves 101 and 102 are opened. As a result, the carrier gas is supplied from the carrier gas supply unit 8 to the carrier gas introduction pipe 10. At the same time, the non-condensed gas outlet valve 421 and the valve 105 are opened, and the circulation pump 12 is operated. As a result, the non-condensable gas in the refrigerant recovery container 42 is discharged through the non-condensed gas outlet valve 421 and merges with the carrier gas in the carrier gas introduction pipe 10. Therefore, since the carrier gas from the carrier gas supply unit 8 and the non-condensable gas from the refrigerant recovery container 42 are introduced into the building multi-air conditioner via the carrier gas introduction pipe 10, The refrigerant becomes a refrigerant mixed gas mixed with the carrier gas and the non-condensable gas. That is, the non-condensed gas discharged from the non-condensed gas outlet valve 421 and the carrier gas introduced from the carrier gas supply unit 8 are circulated through the building multi-air conditioner and the refrigerant recovery unit 4 and recycled. The flow rates of the carrier gas and the non-condensable gas are managed by the flow rate sensor 13.

  In the separation and recovery mode, the opening degree of the valve 100 and the flow rate of the mixed gas of the carrier gas and the non-condensed gas (for example, the opening degree of the valves 101, 102, and 105, the flow rate of the flow rate adjusting unit 9) are controlled. Thus, the pressure in the building multi-air conditioner is adjusted to be maintained at a predetermined value or higher. Furthermore, you may implement the rotation speed control of the compressor 40 and the circulation pump 12, and the opening degree control of the non-condensable gas outlet valve 421 as needed.

  In the refrigerant recovery unit 4, the refrigerant mixed gas is sucked and compressed by the compressor 40 and introduced into the condenser 41. The refrigerant mixed gas introduced into the condenser 41 acts so that only the refrigerant component is condensed and the carrier gas component is not condensed. That is, of the refrigerant mixed gas introduced from the refrigerant inlet valve 420, only the refrigerant component is stored in the refrigerant recovery container 42 in a liquid state. Other components (mainly, carrier gas components) in the refrigerant mixed gas are sucked as a gas from the non-condensable gas outlet valve 421 by the circulation pump 12 and recycled. In the present embodiment, since the gas discharged from the refrigerant recovery container 42 is recycled to the system, the amount of carrier gas newly supplied from the carrier gas supply unit 8 can be reduced, which is economical. The circulation pump 12 may be a circulation fan, and the type of equipment is not limited as long as gas can be circulated. In the case where the gas can be sufficiently circulated only by the pressure difference in the refrigerant recovery system, the circulation pump 12 is not particularly required to be installed.

  The control unit 11 is continuously input with the pressure value detected by the pressure detection unit 5 and the flow value detected by the flow sensor 13. The control unit 11 transmits a control signal to the flow rate adjusting unit 9 and the valve 100 to adjust the introduction flow rate of the carrier gas in order to maintain the pressure in the building multi-air conditioner at a predetermined value or higher. That is, from the carrier gas supply unit 8 so as to compensate for the shortage of the gas flow rate recirculated from the refrigerant recovery container 42 with respect to the gas flow rate necessary to maintain the pressure in the building multi-air conditioner. Introduce new carrier gas. The necessary gas flow rate is stored in the flow rate sensor 13 or the control unit 11, and the flow rate value detected by the flow rate sensor 13 is constantly compared with the necessary gas flow rate. In the separation and recovery mode, as the recovery proceeds, the gas composition in the building multi-air conditioner becomes richer in the carrier gas component. For this reason, it is characteristic that the concentration of the refrigerant introduced into the refrigerant recovery unit 4 tends to decrease as the recovery time elapses.

  When the flow rate of the mixed gas of the carrier gas and the non-condensed gas is too large to maintain a predetermined pressure, the control unit 11 controls the flow rate adjusting unit 9 so as to reduce the flow rate of the carrier gas. When the flow rate needs to be greatly reduced, the control unit 11 opens the valve 103 as appropriate, and discharges the mixed gas of the carrier gas and the non-condensed gas to the outside through the mixed gas discharge path 504. Thereby, the gas flow rate which ventilates the carrier gas introduction pipe 10 can be reduced.

  Note that when the valve 103 or the valve 104 is opened, the refrigerant component may slightly leak to the atmosphere. Therefore, leakage of the refrigerant to the atmosphere can be suppressed by connecting an adsorbent such as activated carbon to each subsequent stage of the valve 103 and the valve 104.

  As described above, in the present embodiment, when the refrigerant is sucked and collected from the refrigeration air conditioner, the carrier gas is introduced from the outside of the refrigeration air conditioner so that the pressure in the refrigeration air conditioner becomes a predetermined value or more. Control. Further, based on the pressure in the refrigeration air conditioner, the refrigerant recovery mode is basically irreversibly switched, such as a normal recovery mode in the initial recovery period and a separation recovery mode in which pressure control is performed by introducing carrier gas in the latter recovery period. As a result, it is possible to suppress the low-temperature condensation of the refrigerant that has occurred in the second half of the refrigerant recovery operation and to suppress a decrease in the recovery rate of the gas refrigerant. Therefore, it is possible to reduce the time for collecting the refrigerant compared to the conventional case. In addition, the non-condensable gas and carrier gas responsible for pressure control in the refrigeration and air conditioning equipment are discharged from the refrigerant recovery container and then circulated again to the refrigeration and air conditioning equipment, thus reducing the flow rate of newly introduced carrier gas. Can be economical.

Embodiment 3 FIG.
A refrigerant recovery system and a refrigerant recovery method according to Embodiment 3 of the present invention will be described. FIG. 6 is a system diagram showing a device configuration, a control system, a flow system, and the like of the refrigerant recovery system according to the present embodiment. In addition, about the component which has the function and effect | action same as Embodiment 1 and 2, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  The refrigerant recovery system according to the present embodiment has substantially the same configuration as that of the second embodiment and operates in substantially the same manner, but differs in that the gas heating unit 14 is installed in the carrier gas introduction pipe 10. . The gas heating unit 14 contributes to suppression of temperature decrease in the building multi-air conditioner. Specifically, the gas heating unit 14 is provided on the downstream side of the flow rate sensor 13 in the carrier gas introduction pipe 10. The gas heating unit 14 has a function of heating the carrier gas and the non-condensable gas introduced into the building multi-air conditioner via the carrier gas introduction pipe 10.

  Due to the pressure drop associated with the refrigerant recovery, the temperature in the building multi-air conditioner decreases, and low-temperature condensation of the refrigerant occurs. In order to suppress the decrease in the recovery rate due to low-temperature condensation, in addition to the suppression of the pressure drop in the multi-air conditioner for buildings due to the introduction of the carrier gas and the recycling of the non-condensed gas shown in the first and second embodiments, It is effective to give heat from the outside so that the temperature in the multi-air conditioner does not decrease reliably.

  The gas heating unit 14 gives heat to the mixed gas of the non-condensable gas and the carrier gas introduced into the building multi-air conditioner via the carrier gas introduction pipe 10 and converts it into hot gas. The hot gas that has received the amount of heat is introduced into the building multi-air conditioner and acts to give heat to the refrigerant in the building multi-air conditioner. In the present embodiment, as shown in the first and second embodiments, the pressure in the building multi-air conditioner detected by the pressure detection unit 5 is monitored so that the pressure is maintained at a predetermined value or more. In the separation and recovery mode in which the recovery of refrigerant is performed while controlling the flow rate of the carrier gas and the equipment in the system, the above hot gas is used as the gas to compensate for the pressure drop, and the temperature in the building multi-air conditioner does not decrease reliably. Like that.

  The gas heating unit 14 indirectly heats the mixed gas flowing through the inside of the carrier gas introduction pipe 10 by heating. For example, the carrier gas introduction pipe 10 is heated by a heater installed on the outer periphery of the carrier gas introduction pipe 10, a heat source such as hot water or steam, and heat exchange with the exhaust heat of the compressor 40 or the condenser 41 of the refrigerant recovery unit 4. Can give heat. Further, the amount of heat can be directly given to the gas by a gas heating heater installed inside the carrier gas introduction pipe 10. However, when heating the gas directly, considering that the refrigerant to be recovered is slightly flammable, the structure where the refrigerant does not come into direct contact with the heat source, for example, the structure where the heat source is coated with an insulator, etc. It is good to use things.

  The gas heating unit 14 receives an output signal from the control unit 11 and acts to heat the mixed gas of the carrier gas and the non-condensed gas. In the refrigerant recovery system in the present embodiment, the temperature of the refrigerant recovery container 42 may be 60 ° C. or lower, preferably 40 ° C. or lower. This is because, when the refrigerant recovery container 42 is a refrigerant recovery cylinder, the melting plug melting temperature installed in the cylinder is 60 ° C., and the pressure in the refrigerant recovery container 42 as the temperature rises. This is because the pressure difference between the secondary pressure of the compressor 40 of the refrigerant recovery unit 4 and the refrigerant recovery container 42 is reduced due to the rise, and the recovery operation is prevented from becoming difficult. Naturally, since the refrigerant recovery container 42 can be cooled, it is necessary to suppress the temperature rise as much as possible. Therefore, in the gas heating unit 14, the gas temperature introduced into the refrigerant recovery unit 4 needs to determine the temperature to be heated in consideration of the gas temperature rise in the compressor 40, the above viewpoint, and the ambient temperature. There is. When low-temperature condensation occurs in a building multi-air conditioner, the temperature in the building multi-air conditioner, particularly the bottom of the accumulator, becomes below freezing point. Therefore, for example, it is preferable to control the gas heating unit 14 so that the temperature at the bottom of the accumulator is reliably 0 ° C. or higher.

  As described above, in the present embodiment, when the refrigerant is sucked and collected from the refrigeration air conditioner, hot gas is introduced from the outside of the refrigeration air conditioner so that the pressure in the refrigeration air conditioner becomes a predetermined value or more. Control. Further, based on the pressure in the refrigeration air conditioner, the refrigerant recovery mode is basically irreversibly switched, such as a normal recovery mode in the initial recovery period and a separation recovery mode in which pressure control is performed by introducing hot gas in the latter recovery period. As a result, it is possible to suppress the low-temperature condensation of the refrigerant that has occurred in the second half of the refrigerant recovery operation and to suppress a decrease in the recovery rate of the gas refrigerant. Therefore, it is possible to reduce the time for collecting the refrigerant compared to the conventional case. In addition, the hot gas responsible for pressure control in the refrigeration and air conditioning equipment can reliably suppress not only the pressure drop in the refrigeration and air conditioning equipment but also the temperature drop, and promote the vaporization of the low-temperature condensed refrigerant in the refrigeration and air conditioning equipment. It becomes possible.

Embodiment 4 FIG.
A refrigerant recovery system and a refrigerant recovery method according to Embodiment 4 of the present invention will be described. FIG. 7 is a system diagram showing a device configuration, a control system, a flow system, and the like of the refrigerant recovery system according to the present embodiment. In addition, about the component which has the function and effect | action same as Embodiment 1-3, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  The refrigerant recovery system according to the present embodiment has substantially the same configuration as that of the second and third embodiments and operates in substantially the same manner, but the trigger required for transition to the refrigerant recovery mode is the pressure in the building multi-air conditioner. It is different in that it is temperature.

  In the first to third embodiments, the pressure in the building multi-air conditioner is monitored, and when the pressure once falls below a predetermined value, the refrigerant recovery mode is shifted from the normal recovery mode to the separation recovery mode. On the other hand, in the present embodiment, the refrigerant recovery mode is shifted based on the temperature in the building multi-air conditioner detected by the accumulator temperature detection unit 210. That is, in the present embodiment, the accumulator 21 in the outdoor unit 2 detects the temperature of the casing portion of the accumulator 21 or the temperature of the refrigerant in the accumulator 21 as the internal temperature of the refrigeration air conditioner, and sends a detection signal to the control unit 11. An accumulator temperature detector 210 for outputting is provided.

  In the building multi-air conditioner, the low-temperature condensation of the refrigerant mainly occurs at the bottom of the accumulator 21. At that time, the refrigerant is generally dissolved in the compressor oil and cannot be vaporized from the compressor oil due to a temperature drop. Therefore, as a matter of course, in addition to the accumulator 21, the refrigerant may fall in the same state at the bottom of the compressor 22 where the compressor oil is accumulated. However, a crankcase heater is usually installed at the bottom of the compressor 22 to protect the compressor 22. Even if the building multi-air conditioner is stopped, the crankcase heater is turned on if the air-conditioning power breaker is on. The case heater is designed to operate. It is usually recommended that the power receiving breaker is always on. For this reason, the temperature at the bottom of the compressor 22 immediately before the start of the recovery operation is higher than the ambient temperature and is maintained at a somewhat high temperature during the recovery operation, so that it is considered that the refrigerant stagnation at the bottom of the compressor 22 is relatively suppressed. Therefore, it may be considered that the stagnation of the refrigerant occurs only in the accumulator 21. Moreover, the stagnation of the refrigerant accompanying the low temperature condensation can be confirmed by detecting the temperature of the casing bottom of the accumulator 21. In fact, when low temperature condensation occurs, the casing bottom temperature is below freezing, and frost begins to adhere to the casing bottom.

  In the present embodiment, the temperature signal in the building multi-air conditioner detected by the accumulator temperature detection unit 210 is transmitted to the control unit 11, and once this temperature falls below a predetermined value, the normal recovery mode is switched to the separation recovery mode. Is set to migrate. Here, the predetermined value of temperature needs to be a temperature at which accumulation of the refrigerant can be suppressed as much as possible in the accumulator 21. For this reason, for example, the predetermined value is set to 0 ° C., and the mode shift is preferably performed when the temperature at the bottom of the accumulator 21 once falls below 0 ° C. Further, whether or not to change the mode may be determined based on the temperature value as described above, or may be determined based on the time change of the temperature decrease. That is, the predetermined value of the temperature can be appropriately selected and adjusted by the operator according to the ambient temperature at the time of the collection work, the scheduled collection time, and the like. When the separation and recovery mode is entered, hot gas (mixed gas of non-condensed gas and carrier gas) is introduced into the building multi-air conditioner. Since the amount of heat is given to the building multi-air conditioner by the hot gas, the temperature of the remaining refrigerant and its surroundings rises, and the temperature drop due to refrigerant recovery can be suppressed.

  In the present embodiment, the example in which the temperature measured at the casing portion of the accumulator 21 is used as the temperature in the building multi-air conditioner has been described. However, the refrigerant in the building multi-air conditioner or the refrigerant of the refrigerant recovery system You may utilize the refrigerant | coolant temperature measured in the collection | recovery path | route (for example, piping part from the manifold 3 to the refrigerant | coolant collection | recovery part 4) as the temperature in the multi air conditioner for buildings.

  In the present embodiment, the pressure detected by the pressure detector 5 is applied to an interlock operation when the pressure in the building multi-air conditioner becomes an abnormal value. When the temperature of the refrigerant rises, the pressure also rises. In particular, the mixed refrigerant tends to increase in pressure as compared with a single refrigerant. Since the rise in pressure affects the operation of the compressor 40 of the refrigerant recovery unit 4, the abnormal value may be determined in consideration of the specifications of the compressor 40 and the pressure resistance of the multi air conditioner for buildings.

  As described above, in the present embodiment, when the refrigerant is sucked and collected from the refrigeration air conditioner, hot gas is introduced from the outside of the refrigeration air conditioner so that the temperature in the refrigeration air conditioner becomes a predetermined value or more. Control. Further, based on the temperature in the refrigeration air conditioner, the refrigerant recovery mode is basically irreversibly switched, such as a normal recovery mode in the initial recovery period and a separation recovery mode in which temperature control is performed by introducing hot gas in the latter recovery period. Thereby, vaporization of the liquid refrigerant can be promoted, and a decrease in the recovery rate of the gas refrigerant can be suppressed. Therefore, it is possible to reduce the time for collecting the refrigerant compared to the conventional case.

Embodiment 5 FIG.
A refrigerant recovery system and a refrigerant recovery method according to Embodiment 5 of the present invention will be described. FIG. 8 is a system diagram showing a device configuration, a control system, a flow system, and the like of the refrigerant recovery system according to the present embodiment. In addition, about the component which has the same function and effect | action as Embodiment 1-4, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  The refrigerant recovery system according to the present embodiment has substantially the same configuration as that of the second to fourth embodiments and operates in substantially the same manner, but the pressure in the building multi-air conditioner as a trigger required for the transition to the refrigerant recovery mode and It differs in that both temperatures are adopted.

  In the present embodiment, both the pressure and temperature in the building multi-air conditioner are monitored, and when at least one of the pressure and temperature once falls below a predetermined value, the refrigerant recovery mode is changed from the normal recovery mode to the separation recovery mode. Transition. That is, in the normal recovery mode, the control unit 11 compares the pressure detected by the pressure detection unit 5 and the temperature detected by the accumulator temperature detection unit 210 with respective predetermined values. When at least one of the pressure and temperature once falls below a predetermined value, the control unit 11 shifts to the separation and recovery mode, opens the valves 101, 102, and 105, and operates the circulation pump 12 and the gas heating unit 14. Let As a result, the hot gas in which the amount of heat is given to the mixed gas of the carrier gas and the non-condensable gas is supplied and circulated in the building multi-air conditioner. During the separation and recovery mode, the control unit 11 monitors the pressure detected by the pressure detection unit 5 and the temperature detected by the accumulator temperature detection unit 210, and the flow rate adjustment unit 9 determines the pressure and temperature based on the pressure and temperature. Adjustment of the flow rate of the carrier gas, control of the capacity of the gas heating unit 14, adjustment of the opening of the valves 100, 103, 104, etc., control of the rotational speed of the compressor 40 and the circulation pump 12, and the like are executed. This maintains the pressure and temperature in the system.

  As described above, in the present embodiment, when the refrigerant is sucked and collected from the refrigeration air-conditioning equipment, hot gas is introduced from the outside of the refrigeration air-conditioning equipment, and both the pressure and temperature in the refrigeration air-conditioning equipment are equal to or higher than a predetermined value. Control to be Also, based on the pressure and temperature in the refrigeration and air-conditioning equipment, the refrigerant recovery mode is basically irreversible, such as the normal recovery mode at the beginning of recovery and the separation recovery mode that controls the pressure and temperature by introducing hot gas in the latter period of recovery. Switch. As a result, it is possible to suppress the low-temperature condensation of the refrigerant that has occurred in the second half of the refrigerant recovery operation and to suppress a decrease in the recovery rate of the gas refrigerant. Therefore, it is possible to reduce the time for collecting the refrigerant compared to the conventional case. Further, as compared with the conventional case, since the refrigerant recovery mode is changed when at least one of the pressure and temperature in the refrigeration air conditioner falls below a predetermined value, the low-temperature condensation of the refrigerant can be greatly suppressed, and the sleeping refrigerant The existence of can be avoided. Therefore, an extremely high refrigerant recovery rate can be realized.

Embodiment 6 FIG.
A refrigerant recovery system and a refrigerant recovery method according to Embodiment 6 of the present invention will be described. FIG. 9 is a system diagram showing a device configuration, a control system, a flow system, and the like of the refrigerant recovery system according to the present embodiment. In addition, about the component which has the function and effect | action same as Embodiment 1-5, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  The configuration of the refrigerant recovery system according to the present embodiment will be described. The refrigerant recovery system according to the present embodiment has a plurality of refrigerant recovery modes in order to monitor the state of the building multi-air conditioner and suppress a decrease in the recovery rate due to the low-temperature condensation of the refrigerant. It is almost the same as 5. However, the refrigerant recovery system according to the present embodiment changes the refrigerant recovery path when the refrigerant recovery mode shifts from the normal recovery mode to the separation recovery mode. The difference is that the gas separation unit 43 provided is used. The trigger required for the transition to the refrigerant recovery mode is the pressure in the building multi-air conditioner.

  In the refrigerant recovery system according to the present embodiment, the refrigerant recovery path 500 is branched into the first refrigerant recovery path 400 and the second refrigerant recovery path 401 at the rear stage (discharge side and secondary side) of the compressor 40. doing. The first refrigerant recovery path 400 has substantially the same configuration as in the first to fifth embodiments, and includes a condenser 41 and a refrigerant recovery container 42. However, in the first refrigerant recovery path 400, a valve 106 is provided in front of the condenser 41. The second refrigerant recovery path 401 is provided with a valve 107, a gas separation unit 43, and a valve 108 in this order. The rear stage side of the valve 108 is connected to the carrier gas introduction pipe 10 via the separation part exhaust gas recirculation path 505 provided with the leak concentration detection part 7, the valve 105 and the circulation pump 12. The valves 106 and 107 function as path switching means for switching the path between the first refrigerant recovery path 400 and the second refrigerant recovery path 401. As the path switching means, a three-way valve or the like can be used instead of the valves 106 and 107.

  Next, the refrigerant recovery operation in the present embodiment will be described. Before the recovery operation, the valves 100 and 106 to 108 in the refrigerant recovery unit 4 connected to the manifold 3 are closed. When starting the refrigerant recovery, the refrigerant recovery mode is set to the normal recovery mode, the compressor 40 is operated, and the valves 100 and 106 are opened. The gas refrigerant sucked into the refrigerant recovery unit 4 from the building multi-air conditioner is introduced into the first refrigerant recovery path 400. The gas refrigerant introduced into the first refrigerant recovery path 400 is increased in temperature and pressure by the compressor 40, passes through the condenser 41, and is recovered as a liquid refrigerant in the refrigerant recovery container 42. At this time, as a matter of course, the refrigerant inlet valve 420 is opened, and the non-condensed gas outlet valve 421 is closed in principle. The refrigerant recovery container 42 can be appropriately cooled, and the rise in temperature and pressure in the refrigerant recovery container 42 can be suppressed. The non-condensed gas outlet valve 421 may be appropriately opened and closed to be used for releasing the pressure in the refrigerant recovery container 42. The refrigerant recovery mode using the first refrigerant recovery path 400 corresponds to the normal recovery mode.

  As the refrigerant recovery in the normal recovery mode proceeds, the amount of refrigerant remaining in the building multi-air conditioner decreases, so the pressure in the building multi-air conditioner gradually decreases. The pressure detection unit 5 is configured to issue an output signal to the control unit 11 once the pressure detected by the pressure detection unit 5 falls below a predetermined pressure value. In the control unit 11, the refrigerant recovery mode is shifted from the normal recovery mode to the separation recovery mode in accordance with the output signal. Note that the mode transition described above is basically irreversible, and after shifting to the separation and recovery mode, the normal recovery mode is not returned until the recovery is completed.

  When receiving the output signal from the pressure detection unit 5, the control unit 11 opens the valves 105, 107, and 108, closes the valve 106, the refrigerant inlet valve 420, and the non-condensed gas outlet valve 421, and sets the refrigerant recovery path. Is switched from the first refrigerant recovery path 400 to the second refrigerant recovery path 401. At the same time, the circulation pump 12 is operated, the valves 101 and 102 are opened, and the carrier gas is introduced into the building multi-air conditioner from the carrier gas supply unit 8. The refrigerant recovery mode using the second refrigerant recovery path 401 and the carrier gas corresponds to the separation recovery mode.

  In the initial stage of the separation and recovery mode, carrier gas is introduced into the building multi-air conditioner. For this reason, the refrigerant | coolant which remains in the multi air conditioner for buildings turns into a mixed gas with carrier gas. That is, the gas to be collected is diluted with the carrier gas and becomes a refrigerant mixed gas having a reduced concentration. The refrigerant mixed gas is sucked from the building multi-air conditioner by the compressor 40 and introduced into the gas separation unit 43. The refrigerant mixed gas introduced into the gas separation unit 43 is adsorbed and collected by the adsorbent provided in the gas separation unit 43, and the remaining components are discharged as non-adsorbed gas to the secondary side of the gas separation unit 43. Is done. As described above, in the separation and recovery mode, unlike the normal recovery mode, the refrigerant to be recovered is recovered not in the refrigerant recovery container 42 but in the adsorbent of the gas separation unit 43.

  The non-adsorbed gas discharged from the gas separation unit 43 is sucked by the circulation pump 12, mixed with the carrier gas, and returned to the building multi-air conditioner via the carrier gas introduction pipe 10. That is, when the separation and recovery mode proceeds, the mixed gas of the carrier gas and the non-adsorbed gas is recirculated into the building multi-air conditioner. For this reason, the remaining refrigerant in the building multi-air conditioner becomes a refrigerant mixed gas diluted with a mixed gas of the carrier gas and the non-adsorbed gas. By introducing the mixed gas of the carrier gas and the non-adsorbed gas, the pressure in the building multi-air conditioner does not drop more than necessary, so that the low-temperature condensation of the refrigerant accompanying the pressure drop in the building multi-air conditioner is suppressed. In the configuration shown in FIG. 9, the carrier gas introduction pipe 10 is connected to both the gas pipe and the liquid pipe of the building multi-air conditioner. However, the carrier gas introduction pipe 10 is a gas pipe or a liquid pipe of the building multi-air conditioner. You may connect to either one of these.

  The control unit 11 is continuously input with the pressure value detected by the pressure detection unit 5 and the flow value detected by the flow sensor 13. The control unit 11 transmits a control signal to the flow rate adjusting unit 9 and the valve 100 to adjust the introduction flow rate of the carrier gas in order to maintain the pressure in the building multi-air conditioner at a predetermined value or higher. That is, the carrier gas supply unit 8 is configured to make up for the shortage of the gas flow rate recirculated from the second refrigerant recovery path 401 with respect to the gas flow rate required to maintain the pressure in the building multi-air conditioner. To introduce a new carrier gas. The necessary gas flow rate is stored in the flow rate sensor 13 or the control unit 11, and the flow rate value detected by the flow rate sensor 13 is constantly compared with the necessary gas flow rate. In the separation and recovery mode, as the recovery proceeds, the gas composition in the building multi-air conditioner becomes richer in the carrier gas component. For this reason, it is characteristic that the concentration of the refrigerant introduced into the gas separation unit 43 tends to decrease and the non-adsorbed gas flow rate tends to increase as the recovery time elapses.

  FIG. 10 is a system diagram showing the configuration of the gas separation unit 43 of the refrigerant recovery system according to the present embodiment. The gas separation unit 43 includes an adsorbent 430 that adsorbs and collects refrigerant components, an adsorption tower 431 filled with the adsorbent 430, an adsorption pressure adjustment unit 432 that adjusts the pressure in the adsorption tower 431, and an adsorption tower 431. An adsorption temperature adjusting unit 433 for adjusting the temperature. Further, the control unit 11 stores in advance as a table the relationship between the type of refrigerant, the refrigerant concentration, and the adsorption operation (temperature and pressure conditions). The control unit 11 receives the signal of the refrigerant concentration detected by the refrigerant concentration detection unit 6 and controls the adsorption pressure adjustment unit 432 and the adsorption temperature adjustment unit 433 according to the signal. Thereby, it is possible to maintain optimum adsorption operation conditions during the separation and recovery mode. That is, it is possible to continuously and automatically follow the adsorption operation condition with respect to the refrigerant concentration that changes from moment to moment, and always realize high adsorption efficiency.

  The adsorption pressure adjustment unit 432 is installed at the rear stage of the adsorption tower 431. The adsorption pressure adjustment unit 432 adjusts the opening of the valve in the adsorption pressure adjustment unit 432 so that the pressure in the adsorption tower 431 is constant. The adsorption temperature adjustment unit 433 is connected to the adsorption tower 431. The adsorption temperature adjusting unit 433 supplies a medium such as water adjusted to a predetermined temperature to the adsorption tower 431 for circulation. In the adsorption of the refrigerant, it is generally beneficial to increase the pressure and decrease the temperature. In the separation and recovery mode, the refrigerant concentration decreases as the recovery time elapses, so that the adsorption efficiency inevitably decreases when the adsorption conditions remain constant. Therefore, the adsorption pressure adjustment unit 432 acts to increase the pressure in the adsorption tower 431 according to the refrigerant concentration detected by the refrigerant concentration detection unit 6 or the elapse of the recovery time, and the adsorption temperature adjustment unit 433 It acts to lower the temperature in the tower 431.

  In this example, the pressure adjustment of the adsorption tower 431 is performed using the adsorption pressure adjustment unit 432, but the pressure adjustment of the adsorption tower 431 is controlled by controlling the rotational speed of at least one of the compressor 40 and the circulation pump 12. May be implemented. In this example, the temperature of the adsorption tower 431 is adjusted using the adsorption temperature adjusting unit 433. However, the temperature of the adsorption tower 431 is adjusted using heat exchange with exhaust heat in the system, air cooling equipment, or the like. You may implement.

  As the adsorbent 430 used in the gas separation unit 43, at least one of silica gel, porous silica, activated alumina, activated carbon, molecular sieve (so-called zeolite), and molecular sieve carbon is employed. In the separation and recovery mode, the refrigerant mixed gas introduced into the gas separation unit 43 is separated into the refrigerant and the carrier gas by the adsorbent 430. The adsorbent 430 can be appropriately selected based on the composition to be collected, that is, the refrigerant species and the carrier gas species, the adsorption temperature control range, the pressure control range, and the like. In the present embodiment, since the adsorption target gas is passed through the filled adsorbent 430, the adsorbent 430 particles preferably have a small particle size and a bead shape.

The refrigerant concentration detection unit 6 transmits a signal of the detected refrigerant concentration to the control unit 11. In the control unit 11, it is possible to determine the remaining refrigerant concentration or the remaining refrigerant amount based on the refrigerant concentration signal, and to determine the end of the collection operation. In the separation and recovery mode in the present embodiment, unlike the normal recovery mode, the refrigerant is not recovered in the refrigerant recovery container 42 but is recovered in the adsorbent 430 provided in the gas separation unit 43. Therefore, the completion of the refrigerant recovery operation cannot be determined only by the weight management of the refrigerant recovery container 42 as in the prior art. When the refrigerant concentration is used for the end determination, the residual refrigerant concentration is, for example, not more than the atmospheric release limit amount of the refrigerant (for example, 0.30 kg / m ^{3 in} the case of R410A or R407C), or when the refrigerant amount is used for the end determination. The termination condition can be set such that the remaining refrigerant amount is, for example, 1% or less (the recovery rate is 99% or more) of the initial refrigerant charging amount. In the conventional collection work, the above-described high-accuracy collection is practically impossible due to the long work time. However, according to the present embodiment, the collection work can be shortened. Realization of a high recovery rate that suppresses the amount of refrigerant released to the atmosphere as much as possible is also expected.

  In addition, when the adsorbent 430 of the gas separation unit 43 breaks through, the refrigerant to be collected may slightly leak to the outlet side of the adsorption tower 431. That is, the refrigerant component is mixed in the non-adsorbed gas. When the separation / recovery mode is executed, the non-adsorbed gas is recirculated to the building multi-air conditioner and introduced again into the refrigerant recovery unit 4. In an extreme case, there is no problem even if the refrigerant leaks from the adsorption tower 431 to the outlet side. Absent. However, when determining the end of the recovery operation, the leakage concentration detection unit 7 is installed at the subsequent stage of the gas separation unit 43 from the viewpoint of strictly managing the amount of refrigerant released into the atmosphere and clarifying the recovery rate of the refrigerant. Measures such as exchanging the adsorbent 430 are performed at the stage where the refrigerant leak is confirmed, and the refrigerant is thoroughly collected.

  The adsorbent 430 that has adsorbed the refrigerant differs in disposal processing depending on the type of adsorbent. When the adsorbent is activated carbon, the entire adsorbent can be processed by combustion, as in the conventional refrigerant destruction process. Since the activated carbon itself is extremely low-cost, the disposal process is more reasonable than considering the reuse of the refrigerant. On the other hand, in the case of molecular sieves or the like, the refrigerant can be reused by desorption. When it is discarded without being reused, it becomes industrial waste, so a predetermined procedure is required.

  As described above, in the present embodiment, when the refrigerant is sucked and collected from the refrigeration air conditioner, the carrier gas is introduced from the outside of the refrigeration air conditioner so that the pressure in the refrigeration air conditioner becomes a predetermined value or more. Control. In addition, based on the pressure in the refrigeration and air-conditioning equipment, the normal recovery mode using the first refrigerant recovery path is used in the initial stage of recovery, and the pressure control is performed by introducing carrier gas in the latter stage of recovery. As in the mode, the refrigerant recovery mode and the refrigerant recovery path are basically irreversibly switched. As a result, it is possible to suppress the low-temperature condensation of the refrigerant that has occurred in the second half of the refrigerant recovery operation and to suppress a decrease in the recovery rate of the gas refrigerant. In addition, the refrigerant recovery mode can be continuously shifted, and the recovery of the refrigerant and the promotion of vaporization of the remaining refrigerant can be performed simultaneously. Therefore, it is possible to achieve a significantly shortened time for refrigerant recovery work as compared with the prior art. Furthermore, since the judgment based on the refrigerant concentration or quantity of refrigerant to be collected can be adopted for the judgment of the end of collection, a higher refrigerant recovery rate can be realized with higher accuracy and the amount of refrigerant leakage to the atmosphere can be suppressed as much as possible. be able to.

Embodiment 7 FIG.
A refrigerant recovery system and a refrigerant recovery method according to Embodiment 7 of the present invention will be described. FIG. 11 is a system diagram showing a device configuration, a control system, a flow system, and the like of the refrigerant recovery system according to the present embodiment. In addition, about the component which has the same function and effect | action as Embodiment 1-6, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  The refrigerant recovery system according to the present embodiment has substantially the same configuration as that of the sixth embodiment and operates in substantially the same manner, but differs in that a gas heating unit 14 is installed in the carrier gas introduction pipe 10. . The gas heating unit 14 contributes to suppression of temperature decrease in the building multi-air conditioner. Due to the pressure drop associated with the refrigerant recovery, the temperature in the building multi-air conditioner decreases, and low-temperature condensation of the refrigerant occurs. In order to suppress the reduction in the recovery rate due to the low temperature condensation, in addition to the suppression of the pressure drop in the building multi-air conditioner by introducing the carrier gas and recycling the non-adsorbed gas shown in the sixth embodiment, It is effective to give heat from the outside so that the temperature inside does not decrease reliably. The trigger required for the transition to the refrigerant recovery mode in the present embodiment is the pressure in the building multi-air conditioner as in the sixth embodiment.

  The gas heating unit 14 shown in FIG. 11 gives heat to the mixed gas of the non-adsorbed gas and the carrier gas introduced into the building multi-air conditioner via the carrier gas introduction pipe 10 and turns it into a hot gas. The hot gas that has received the amount of heat is introduced into the building multi-air conditioner and acts to give heat to the refrigerant in the building multi-air conditioner. In the present embodiment, the pressure in the building multi-air conditioner detected by the pressure detector 5 is monitored, and the refrigerant is controlled while controlling the flow rate of the carrier gas and the devices in the system so that the pressure does not fall below a predetermined value. In the separation and recovery mode in which the recovery is performed, the above hot gas is used as a gas to compensate for the pressure drop so that the temperature in the building multi-air conditioner does not decrease reliably.

  The gas heating unit 14 indirectly heats the mixed gas flowing through the inside of the carrier gas introduction pipe 10 by heating. For example, the carrier gas introduction pipe 10 is heated by a heater installed on the outer periphery of the carrier gas introduction pipe 10, a heat source such as hot water or steam, and heat exchange with the exhaust heat of the compressor 40 or the condenser 41 of the refrigerant recovery unit 4. Can give heat. Further, the amount of heat can be directly given to the gas by a gas heating heater installed inside the carrier gas introduction pipe 10. However, when heating the gas directly, considering that the refrigerant to be recovered is slightly flammable, the structure where the refrigerant does not come into direct contact with the heat source, for example, the structure where the heat source is coated with an insulator, etc. It is good to use things.

  The gas heating unit 14 receives an output signal from the control unit 11 and acts to heat the mixed gas of the non-adsorbed gas and the carrier gas. In the separation and recovery mode using the gas heating unit 14, the refrigerant recovery container 42 is not used for refrigerant recovery, so there is no temperature limitation due to the refrigerant recovery container 42 or the like as described in the third embodiment. In the refrigerant recovery system in the present embodiment, pressure and temperature abnormalities are monitored, and the pressure and temperature are applied to the interlock operation. For this reason, the upper limit of the gas temperature in the gas heating unit 14 may be equal to or lower than the maximum temperature in the building multi-air conditioner, and can be appropriately selected and adjusted by the operator according to the ambient environment temperature, the scheduled recovery time, and the like.

  As described above, in the present embodiment, when the refrigerant is sucked and collected from the refrigeration air conditioner, hot gas is introduced from the outside of the refrigeration air conditioner so that the pressure in the refrigeration air conditioner becomes a predetermined value or more. Control. Also, based on the pressure in the refrigeration and air-conditioning equipment, the normal recovery mode using the first refrigerant recovery path is used in the initial stage of recovery, and the pressure control is performed by introducing hot gas in the latter stage of recovery. As in the mode, the refrigerant recovery mode and the refrigerant recovery path are basically irreversibly switched. As a result, it is possible to suppress the low-temperature condensation of the refrigerant that has occurred in the second half of the refrigerant recovery operation and to suppress a decrease in the recovery rate of the gas refrigerant. In addition, the refrigerant recovery mode can be continuously shifted, and the recovery of the refrigerant and the promotion of vaporization of the remaining refrigerant can be performed simultaneously. Therefore, it is possible to achieve a significantly shortened time for refrigerant recovery work as compared with the prior art. In addition, compared to the conventional case, the stagnation refrigerant can be significantly suppressed, and thus an extremely high refrigerant recovery rate can be realized.

Embodiment 8 FIG.
A refrigerant recovery system and a refrigerant recovery method according to Embodiment 8 of the present invention will be described. FIG. 12 is a system diagram showing a device configuration, a control system, a flow system, and the like of the refrigerant recovery system according to the present embodiment. In addition, about the component which has the function and effect | action same as Embodiment 1-7, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  The refrigerant recovery system according to the present embodiment has substantially the same configuration as that of the sixth and seventh embodiments and operates in substantially the same manner. However, the trigger required for transition to the refrigerant recovery mode is the pressure in the building multi-air conditioner. It is different in that it is temperature.

  In Embodiments 6 and 7, the pressure in the building multi-air conditioner is monitored, and when this pressure once falls below a predetermined value, the refrigerant recovery mode is shifted from the normal recovery mode to the separation recovery mode. On the other hand, in the present embodiment, the refrigerant recovery mode is shifted based on the temperature in the building multi-air conditioner detected by the accumulator temperature detection unit 210.

  When the refrigerant recovery in the normal recovery mode proceeds and the pressure in the building multi-air conditioner decreases, low-temperature condensation of the refrigerant occurs in the building multi-air conditioner. Low temperature condensation occurs mainly at the bottom of the accumulator 21. At that time, the refrigerant is generally dissolved in the compressor oil, and cannot be vaporized from the compressor oil due to a temperature drop. That is, the stagnation of the refrigerant accompanying the low temperature condensation can be confirmed by detecting the temperature of the casing bottom of the accumulator 21.

  In the present embodiment, the temperature signal detected by the accumulator temperature detection unit 210 is transmitted to the control unit 11, and once this temperature falls below a predetermined value, the normal recovery mode is set to shift to the separation recovery mode. Has been. Here, the predetermined value of the temperature needs to be a temperature that can suppress the stagnation of the refrigerant as much as possible at the bottom of the accumulator 21. For this reason, for example, the predetermined value is set to 0 ° C., and the mode shift is preferably performed when the temperature at the bottom of the accumulator 21 once falls below 0 ° C. Further, whether or not to change the mode may be determined based on the temperature value as described above, or may be determined based on the time change of the temperature decrease. That is, the predetermined value of the temperature can be appropriately selected and adjusted by the operator according to the ambient temperature at the time of the collection work, the scheduled collection time, and the like. When the separation and recovery mode is entered, hot gas (a mixed gas of non-adsorbed gas and carrier gas) is introduced into the multi air conditioner for buildings. Since the amount of heat is given to the building multi-air conditioner by the hot gas, the temperature of the remaining refrigerant and its surroundings rises, and the temperature drop due to refrigerant recovery can be suppressed.

  In the present embodiment, the pressure detected by the pressure detector 5 is applied to an interlock operation when the pressure in the building multi-air conditioner becomes an abnormal value. When the temperature of the refrigerant rises, the pressure also rises. In particular, the mixed refrigerant tends to increase in pressure as compared with a single refrigerant. Since the rise in pressure affects the operation of the compressor 40 of the refrigerant recovery unit 4, the abnormal value may be determined in consideration of the specifications of the compressor 40 and the pressure resistance of the multi air conditioner for buildings.

  As described above, in the present embodiment, when the refrigerant is sucked and collected from the refrigeration air conditioner, hot gas is introduced from the outside of the refrigeration air conditioner so that the temperature in the refrigeration air conditioner becomes a predetermined value or more. Control. In addition, based on the temperature in the refrigeration and air-conditioning equipment, a normal recovery mode using the first refrigerant recovery path is in the initial stage of recovery, and a separation recovery mode using the second refrigerant recovery path that performs pressure control by hot gas introduction in the late stage of recovery. Thus, the refrigerant recovery mode and the refrigerant recovery path are basically irreversibly switched. Thereby, vaporization of the liquid refrigerant can be promoted, and a decrease in the recovery rate of the gas refrigerant can be suppressed. In addition, the refrigerant recovery mode can be continuously shifted, and the recovery of the refrigerant and the promotion of vaporization of the remaining refrigerant can be performed simultaneously. Therefore, it is possible to achieve a significantly shortened time for refrigerant recovery work as compared with the prior art.

Embodiment 9 FIG.
A refrigerant recovery system and a refrigerant recovery method according to Embodiment 9 of the present invention will be described. FIG. 13 is a system diagram showing a device configuration, a control system, a flow system, and the like of the refrigerant recovery system according to the present embodiment. In addition, about the component which has the function and effect | action same as Embodiment 1-8, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  The refrigerant recovery system according to the present embodiment has substantially the same configuration as that of the sixth to eighth embodiments and operates in substantially the same manner, but the pressure in the building multi-air conditioner as a trigger required for the transition to the refrigerant recovery mode and It differs in that both temperatures are adopted.

  In the present embodiment, both the pressure and temperature in the building multi-air conditioner are monitored, and when at least one of the pressure and temperature once falls below a predetermined value, the refrigerant recovery mode is changed from the normal recovery mode to the separation recovery mode. Transition. The transition from the normal recovery mode to the separation recovery mode is an irreversible operation. In the normal recovery mode, the control unit 11 compares the pressure detected by the pressure detection unit 5 and the temperature detected by the accumulator temperature detection unit 210 with respective predetermined values. When at least one of the pressure and the temperature once falls below a predetermined value, the control unit 11 shifts to the separation and recovery mode, and controls each valve, the gas heating unit 14 and the like to supply hot gas into the building multi-air conditioner. To be circulated. After shifting to the separation and recovery mode, the control unit 11 monitors the pressure detected by the pressure detection unit 5 and the temperature detected by the accumulator temperature detection unit 210, and the flow rate adjustment unit based on the pressure and temperature. 9, adjustment of the carrier gas introduction flow rate, capacity control of the gas heating unit 14, adjustment of the opening degree of the valves 100 and 103, rotation speed control of the compressor 40 and the circulation pump 12, and the like. This maintains the pressure and temperature in the system.

  As described above, in the present embodiment, when the refrigerant is sucked and collected from the refrigeration air-conditioning equipment, hot gas is introduced from the outside of the refrigeration air-conditioning equipment, and both the pressure and temperature in the refrigeration air-conditioning equipment are equal to or higher than a predetermined value. Control to be In addition, based on the pressure and temperature in the refrigeration and air-conditioning equipment, a normal recovery mode using the first refrigerant recovery path at the initial stage of recovery, and a second refrigerant recovery path for controlling the pressure and temperature by introducing hot gas in the late stage of recovery. The refrigerant recovery mode and the refrigerant recovery path are basically irreversibly switched, such as a separation recovery mode using. As a result, it is possible to suppress the low-temperature condensation of the refrigerant that has occurred in the second half of the refrigerant recovery operation and to suppress a decrease in the recovery rate of the gas refrigerant. Therefore, it is possible to reduce the time for collecting the refrigerant compared to the conventional case. Further, as compared with the conventional case, since the refrigerant recovery mode is changed when at least one of the pressure and temperature in the refrigeration air conditioner falls below a predetermined value, the low-temperature condensation of the refrigerant can be greatly suppressed, and the sleeping refrigerant The existence of can be avoided. Therefore, an extremely high refrigerant recovery rate can be realized.

Embodiment 10 FIG.
A refrigerant recovery system and a refrigerant recovery method according to Embodiment 10 of the present invention will be described. FIG. 14 is a system diagram showing a device configuration, a control system, a flow system, and the like of the refrigerant recovery system according to the present embodiment. In addition, about the component which has the function and effect | action same as Embodiment 1-9, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  Although the basic configuration and operation of the present embodiment are the same as those of the sixth to ninth embodiments, a mixed gas or hot gas recirculated into the building multi-air conditioner through the carrier gas introduction pipe 10 is continuously used. It differs in that it is supplied intermittently rather than intentionally.

  Here, FIG. 14 shows a configuration in the case where the gas heating unit 14 is installed in the carrier gas introduction pipe 10, but in the present embodiment, the case where the gas heating unit 14 is not installed is also shown. It is valid. Further, in the present embodiment, the valve 102 installed in the carrier gas introduction pipe 10 repeats opening and closing operations according to a predetermined pressure or time, and the gas flow recirculated to the building multi-air conditioner is Be controlled. In the present embodiment, the buffer tank 15 is connected to the subsequent stage of the valve 103 in the mixed gas discharge path 504, and the valve 109 is connected to the subsequent stage of the buffer tank 15.

  The refrigerant recovery mode is changed from the normal recovery mode to the separation recovery mode, triggered by at least one of the pressure and temperature in the building multi-air conditioner. In the separation and recovery mode, the non-adsorbed gas and the carrier gas supply unit that are discharged from the gas separation unit 43 so as to maintain at least one of the pressure and temperature in the building multi-air conditioner (pressure in this example) at or above a predetermined value. The mixed gas composed of the carrier gas supplied from 8 or the hot gas obtained by applying a heat amount to the mixed gas is recirculated into the building multi-air conditioner. In the present embodiment, the pressure (or temperature) in the building multi-air conditioner is set to a predetermined value or more, but the pressure (or temperature) is provided with a fluctuation tolerance within a predetermined range with respect to the recovery time. Therefore, the operation of introducing the mixed gas or hot gas into the building multi-air conditioner (for example, the opening / closing operation of the valves 101, 102, 103) is controlled to suppress the new introduction amount of the carrier gas.

  In the separation and recovery mode of the present embodiment, introduction of mixed gas or hot gas so that at least one of the pressure and temperature in the building multi-air conditioner is within a predetermined range equal to or greater than a predetermined value with respect to the recovery time. The opening / closing operation of the valve 102 for adjusting the amount is repeated. When the valve 102 is open, the valve 101 is open and the valves 103 and 109 are closed. In this case, the introduction flow rate of the mixed gas or hot gas is adjusted according to the pressure or temperature of the building multi-air conditioner. When at least one of the pressure and temperature in the building multi-air conditioner (pressure in this example) reaches the upper limit of the predetermined range, the valves 101 and 102 are closed, and the mixed gas or hot gas into the building multi-air conditioner Is blocked. At this time, the gas heating operation in the gas heating unit 14 may also be stopped. At the same time, the valve 103 is opened, and the non-adsorbed gas discharged from the gas separation unit 43 is accumulated in the buffer tank 15. From the viewpoint of filling the buffer tank 15, a compressor may be employed as the circulation pump 12.

  While the buffer tank 15 is filled with the non-adsorbed gas, the separation and recovery mode is continued, and the recovery of the refrigerant in the building multi-air conditioner is progressing. Decreases. When at least one of the pressure and temperature (pressure in this example) reaches the lower limit of the predetermined range, the valve 102 is opened again, and the gas heating unit 14 operates again. As a result, the non-adsorbed gas accumulated in the buffer tank 15 is converted into hot gas and then introduced into the building multi-air conditioner so that at least one of the pressure and temperature in the building multi-air conditioner becomes equal to or higher than a predetermined value. Is done.

  The refrigerant recovery is continued by repeating the above operation during the separation recovery mode. By such an operation, the flow rate of the newly supplied carrier gas and the power of the gas heating unit 14 can be reduced, and the running cost associated with the recovery operation can be reduced. In the above operation, the valve 109 may be appropriately opened when the pressure in the buffer tank 15 increases excessively, and may be used for releasing the pressure in the system. FIG. 15 is a timing chart showing an example of the time-series operation of the pressure in the refrigeration air conditioner (building multi-air conditioner) and the valves 106, 107, 102, 103, 101 of the refrigerant recovery system in the present embodiment.

  As described above, in the present embodiment, when the refrigerant is sucked and collected from the refrigeration air conditioner, hot gas is introduced from the outside of the refrigeration air conditioner, and at least one of the pressure and temperature in the refrigeration air conditioner is a predetermined value. Control is performed as described above. Further, based on at least one of the pressure and temperature in the refrigeration air-conditioning equipment, the initial recovery is the normal recovery mode using the first refrigerant recovery path, and the late recovery is the pressure or temperature in the building multi-air conditioner by introducing hot gas. The refrigerant recovery mode and the refrigerant recovery path are basically irreversibly switched as in the separation recovery mode using the second refrigerant recovery path. As a result, it is possible to suppress the low-temperature condensation of the refrigerant that has occurred in the second half of the refrigerant recovery operation and to suppress a decrease in the recovery rate of the gas refrigerant. Therefore, it is possible to reduce the time for collecting the refrigerant compared to the conventional case. In addition, by setting a permissible fluctuation range for the pressure or temperature controlled in the separation and recovery mode and providing the buffer tank 15 in the system, the mixed gas to be recirculated into the building multi-air conditioner is intermittently supplied. Can do. Therefore, the amount of carrier gas newly introduced can be reduced, which is economical.

Embodiment 11 FIG.
A refrigerant recovery system and a refrigerant recovery method according to Embodiment 11 of the present invention will be described. FIG. 16 is a system diagram showing a device configuration, a control system, a flow system, and the like of the refrigerant recovery system according to the present embodiment. In addition, about the component which has the same function and effect | action as Embodiment 1-10, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  The refrigerant recovery system according to the present embodiment has the same basic configuration and operation as those of the sixth to tenth embodiments, but the mixed gas that is recirculated into the building multi-air conditioner via the carrier gas introduction pipe 10 or The difference is that the hot gas introduction direction is appropriately switched.

  Here, FIG. 16 shows the configuration in the case where the gas heating unit 14 is installed in the carrier gas introduction pipe 10, but in the present embodiment, the case where the gas heating unit 14 is not installed is also shown. It is valid. In the present embodiment, two branched ends of the carrier gas introduction pipe 10 are connected to the liquid pipe 25 and the gas pipe 26 of the building multi-air conditioner, respectively. A valve 111 is provided at the tip connected to the liquid pipe 25, and a valve 110 is provided at the tip connected to the gas pipe 26. During the separation / recovery mode, both the valves 110 and 111 perform reverse opening / closing operations, so that the flow direction of the mixed gas flowing back into the building multi-air conditioner is appropriately switched. That is, by alternately opening and closing the valves 110 and 111 under the control of the control unit 11, the mixed gas or hot gas is alternately introduced into the building multi-air conditioner from the liquid pipe 25 side or from the gas pipe 26 side. The timing for switching between opening and closing of the valves 110 and 111 may be determined based on a preset time interval, or may be determined based on the refrigerant concentration detected by the refrigerant concentration detector 6. For example, if the refrigerant recovery is continued in a state where the valve 110 is open and the valve 111 is closed, the refrigerant concentration detected by the refrigerant concentration detector 6 decreases with time. When the refrigerant concentration decreases to a predetermined concentration, the valve 110 is preferably closed and the valve 111 is switched to open.

  As described above, it is expected that the contact efficiency between the remaining liquid refrigerant or the compressor oil in which the refrigerant is dissolved and the introduced mixed gas or hot gas will be improved by appropriately changing the gas flow state in the building multi-air conditioner. it can. In addition, the four-way valve 20 in the building multi-air conditioner can be operated manually or by an external power source other than the building multi-air conditioner so that the operation of the valves 110 and 111 can be performed by the switching operation of the four-way valve 20. It is possible to substitute, or both may be used in combination.

  As described above, in the present embodiment, when the refrigerant is sucked and collected from the refrigeration air conditioner, hot gas is introduced from the outside of the refrigeration air conditioner, and at least one of the pressure and temperature in the refrigeration air conditioner is a predetermined value. Control is performed as described above. Further, based on at least one of the pressure and temperature in the refrigeration air-conditioning equipment, the initial recovery is the normal recovery mode using the first refrigerant recovery path, and the late recovery is the pressure or temperature in the building multi-air conditioner by introducing hot gas. The refrigerant recovery mode and the refrigerant recovery path are basically irreversibly switched as in the separation recovery mode using the second refrigerant recovery path. As a result, it is possible to suppress the low-temperature condensation of the refrigerant that has occurred in the second half of the refrigerant recovery operation and to suppress a decrease in the recovery rate of the gas refrigerant. Therefore, it is possible to reduce the time for collecting the refrigerant compared to the conventional case. In addition, by appropriately changing the flow direction of the hot gas to be introduced in the building multi-air conditioner, the hot gas reaches everywhere in the building multi-air conditioner, and the remaining liquid refrigerant or the surface of the compressor oil in which the refrigerant is dissolved Is effectively irradiated with hot gas. Thereby, the presence of the stagnation refrigerant can be suppressed, and the recovery rate of the gas refrigerant recovery can be improved.

Embodiment 12 FIG.
A refrigerant recovery system and a refrigerant recovery method according to Embodiment 12 of the present invention will be described. FIG. 17 is a system diagram showing the configuration of the gas separation unit 43 of the refrigerant recovery system according to the present embodiment. In addition, about the component which has the same function and effect | action as Embodiment 1-11, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  The refrigerant recovery system according to the present embodiment has the same basic configuration and operation as those of Embodiments 6 to 11, but the gas heating unit 14 uses the amount of heat generated by the gas separation unit 43 as a heat source. It is different.

  In the gas separation unit 43, only the refrigerant component is selectively adsorbed and separated from the refrigerant mixed gas in the separation and recovery mode. The adsorption operation is an exothermic reaction and generates heat of adsorption. The present embodiment is characterized in that the amount of heat of this adsorption heat is given to the mixed gas that is ventilated through the carrier gas introduction pipe 10 via the heat exchanger 16, and the mixed gas is turned into a hot gas.

  As shown in the sixth embodiment, the temperature of the adsorption tower 431 in the gas separation unit 43 is adjusted by the adsorption temperature adjustment unit 433. In the present embodiment, the heat exchanger 16 corresponds to the adsorption temperature adjustment unit 433. On the primary side of the heat exchanger 16, heat generated in the adsorption tower 431 is removed by circulating a primary fluid such as water. On the secondary side of the heat exchanger 16, the amount of heat obtained by the primary side fluid is transferred to the gas heating unit 14 by a secondary side fluid such as water. That is, the secondary fluid of the heat exchanger 16 acts on the heating of the mixed gas of the non-adsorbed gas and the carrier gas supplied to the building multi-air conditioner in the separation and recovery mode.

  As described above, in the present embodiment, when the refrigerant is sucked and collected from the refrigeration air conditioner, hot gas is introduced from the outside of the refrigeration air conditioner, and at least one of the pressure and temperature in the refrigeration air conditioner is a predetermined value. Control is performed as described above. Further, based on at least one of the pressure and temperature in the refrigeration air-conditioning equipment, the initial recovery is the normal recovery mode using the first refrigerant recovery path, and the late recovery is the pressure or temperature in the building multi-air conditioner by introducing hot gas. The refrigerant recovery mode and the refrigerant recovery path are basically irreversibly switched as in the separation recovery mode using the second refrigerant recovery path. As a result, it is possible to suppress the low-temperature condensation of the refrigerant that has occurred in the second half of the refrigerant recovery operation and to suppress a decrease in the recovery rate of the gas refrigerant. Therefore, it is possible to reduce the time for collecting the refrigerant compared to the conventional case. In addition, since the mixed gas of the non-adsorbed gas and the carrier gas is converted into hot gas using the adsorption heat generated in the gas separation unit, another heat source is not required, which is economical.

Embodiment 13 FIG.
A refrigerant recovery system and a refrigerant recovery method according to Embodiment 13 of the present invention will be described. FIG. 18 is a system diagram showing a device configuration, a control system, a flow system, and the like of the refrigerant recovery system according to the present embodiment. In addition, about the component which has the same function and effect | action as Embodiment 1-12, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  The configuration of the refrigerant recovery system according to the present embodiment will be described. The refrigerant recovery system according to the present embodiment has a plurality of refrigerant recovery modes in order to monitor the state of the building multi-air conditioner and suppress a decrease in the recovery rate due to the low-temperature condensation of the refrigerant. 12 is almost the same. However, the refrigerant recovery system according to the present embodiment is different in that a commercially available refrigerant recovery device is used for the refrigerant recovery path used in the normal recovery mode. The trigger required for the transition to the refrigerant recovery mode is at least one of pressure and temperature in the building multi-air conditioner. FIG. 18 shows an example in which the present embodiment is applied to the configuration of the ninth embodiment. Note that this embodiment can be applied not only in Embodiment 9 but also in combination with the configurations of all the embodiments in the present invention.

  The refrigerant recovery unit 4 of the refrigerant recovery system in the present embodiment includes a first refrigerant recovery path 400 that uses a commercially available refrigerant recovery device 44 and a second refrigerant recovery path 401 that includes a gas separation unit 43. In the first refrigerant recovery path 400, a valve 112, a commercially available refrigerant recovery device 44, and a refrigerant recovery container 42 are installed in this order. In the second refrigerant recovery path 401, a valve 113, a compressor 40, a valve 107, a gas separation unit 43, and a valve 108 are installed in this order. The further downstream side of the valve 108 is connected to the carrier gas introduction pipe 10 via a separation part exhaust gas recirculation path 505 provided with the leak concentration detection part 7, the valve 105 and the circulation pump 12.

  In the normal recovery mode in the present embodiment, that is, when at least one of the pressure and temperature in the building multi-air conditioner is larger than a predetermined value, the commercial refrigerant recovery device 44 installed in the first refrigerant recovery path 400 uses the gas refrigerant. Is collected in the refrigerant recovery container 42 as a liquid refrigerant. That is, in the normal recovery mode, the valve 112 and the refrigerant inlet valve 420 are open, the valve 113 is closed, and the non-condensed gas outlet valve 421 is closed in principle. The commercial refrigerant recovery device 44 includes a compressor, a condenser disposed at the rear stage of the compressor, and a control system that controls the entire commercial refrigerant recovery device 44. The refrigerant recovery mode shifts from the normal recovery mode to the separation recovery mode when at least one of the pressure and temperature in the building multi-air conditioner once falls below a predetermined value. When the separation and recovery mode is entered, the control of the control unit 11 switches the refrigerant recovery path from the first refrigerant recovery path 400 to the second refrigerant recovery path 401. That is, the valve 112 is closed and the valve 113 is opened. The commercial refrigerant recovery device 44 continues to operate for several minutes after the refrigerant recovery mode is switched to the separation recovery mode, and is stopped after the remaining refrigerant in the downstream path of the valve 112 is completely recovered. Thereafter, the refrigerant inlet valve 420 is preferably closed.

  In the separation and recovery mode, the non-adsorbed gas discharged from the gas separation unit 43 and the carrier supplied from the carrier gas supply unit 8 so as to maintain at least one of the pressure and temperature in the building multi-air conditioner at a predetermined value or more. The mixed gas consisting of gas is recirculated into the building multi-air conditioner. This mixed gas is given a heat quantity by the gas heating unit 14 and becomes a hot gas. In addition, this Embodiment is effective also when the gas heating part 14 is not installed.

  As described above, in the present embodiment, when the refrigerant is sucked and collected from the refrigeration air-conditioning equipment, the mixed gas or hot gas is introduced from the outside of the refrigeration air-conditioning equipment, and at least one of the pressure and temperature in the refrigeration air-conditioning equipment. Is controlled to be equal to or greater than a predetermined value. In addition, based on at least one of the pressure and temperature in the refrigeration and air conditioning equipment, the initial recovery stage is a normal recovery mode using a commercially available refrigerant recovery device provided in the first refrigerant recovery path, and a mixed gas or hot gas is introduced in the latter stage of recovery. The refrigerant recovery mode and the refrigerant recovery path are basically irreversibly switched, such as a separation / recovery mode using the second refrigerant recovery path, which controls the pressure or temperature by. As a result, it is possible to suppress the low-temperature condensation of the refrigerant that has occurred in the second half of the refrigerant recovery operation and to suppress a decrease in the recovery rate of the gas refrigerant. Therefore, it is possible to reduce the time for collecting the refrigerant compared to the conventional case. In addition, since a commercially available refrigerant recovery device can be used in the normal recovery mode, the user only needs to add equipment to be applied in the separation recovery mode shown in the present embodiment to the current recovery facility, which is economical. It is.

Embodiment 14 FIG.
A refrigerant recovery system and a refrigerant recovery method according to Embodiment 14 of the present invention will be described. FIG. 19 is a system diagram showing a device configuration, a control system, a flow system, and the like of the refrigerant recovery system according to the present embodiment. In addition, about the component which has the function and effect | action same as Embodiment 1-13, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  The refrigerant recovery system according to the present embodiment monitors the state of the building multi-air conditioner, and includes a plurality of recovery modes in order to suppress a decrease in the recovery speed due to the low-temperature condensation of the refrigerant. Is almost the same. However, in the refrigerant recovery system according to the present embodiment, in the separation and recovery mode, the circulation pump 12 acting on the circulation of the non-condensed gas or the non-adsorbed gas shown in the second to thirteenth embodiments is the ejector 120. It is different. The trigger required for the transition to the refrigerant recovery mode is at least one of pressure and temperature in the building multi-air conditioner. FIG. 19 shows an example in which the present embodiment is applied to the configuration of the ninth embodiment. Note that this embodiment can be applied not only in Embodiment 9 but also in combination with the configurations of all the embodiments in the present invention.

  In the separation / recovery mode, the non-adsorbed gas separated in the gas separation unit 43 is mixed with the carrier gas by the ejector 120 and returned to the building multi-air conditioner. The non-adsorbed gas is sucked from the gas separation unit 43 by the suction force of the ejector 120 using the carrier gas as the driving gas. Therefore, an electric drive source such as a circulation pump is not required, and a mixed gas of non-adsorbed gas and carrier gas can be supplied to the carrier gas introduction pipe 10.

  As described above, in the present embodiment, when the refrigerant is sucked and collected from the refrigeration air-conditioning equipment, the mixed gas or hot gas is introduced from the outside of the refrigeration air-conditioning equipment, and at least one of the pressure and temperature in the refrigeration air-conditioning equipment. Is controlled to be equal to or greater than a predetermined value. In addition, based on at least one of the pressure and temperature in the refrigeration and air conditioning equipment, the normal recovery mode using the first refrigerant recovery path is used in the initial stage of recovery, and the pressure or temperature is controlled by introducing mixed gas or hot gas in the late stage of recovery. The refrigerant recovery mode and the refrigerant recovery path are basically irreversibly switched as in the separation recovery mode using the second refrigerant recovery path. As a result, it is possible to suppress the low-temperature condensation of the refrigerant that has occurred in the second half of the refrigerant recovery operation and to suppress a decrease in the recovery rate of the gas refrigerant. Therefore, it is possible to reduce the time for collecting the refrigerant compared to the conventional case. Further, since the non-adsorbed gas or the non-condensed gas is recirculated into the building multi-air conditioner by the ejector using the carrier gas as the driving gas, the power for circulating the mixed gas is unnecessary, which is economical.

Embodiment 15 FIG.
A refrigerant recovery system and a refrigerant recovery method according to Embodiment 15 of the present invention will be described. FIG. 20 is a system diagram showing a device configuration, a control system, a flow system, and the like of the refrigerant recovery system according to the present embodiment. In addition, about the component which has the function and effect | action same as Embodiment 1-14, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  The refrigerant recovery system according to the present embodiment monitors the state of the building multi-air conditioner, and includes a plurality of recovery modes in order to suppress a decrease in the recovery rate due to the low-temperature condensation of the refrigerant. Is almost the same. However, in the refrigerant recovery system according to the present embodiment, in the separation and recovery mode, the circulation pump 12 acting on the circulation of the non-condensed gas or the non-adsorbed gas shown in the embodiments 2 to 14 becomes the circulation compressor 121. The difference is that the gas heating unit 14 is not provided. The trigger required for the transition to the refrigerant recovery mode is at least one of pressure and temperature in the building multi-air conditioner. FIG. 20 shows an example in which the present embodiment is applied to the configuration of the ninth embodiment. Note that this embodiment can be applied not only in Embodiment 9 but also in combination with the configurations of all the embodiments in the present invention.

  In the separation / recovery mode, the non-adsorbed gas separated in the gas separation unit 43 is mixed with a newly introduced carrier gas and is returned to the building multi-air conditioner. In the present embodiment, the non-adsorbed gas is recirculated by the circulation compressor 121. The non-adsorbed gas is sucked from the gas separation unit 43 by the suction force of the circulation compressor 121, and the sucked non-adsorbed gas is increased in temperature and pressure in the circulation compressor 121. Therefore, in this Embodiment, it becomes possible to produce | generate a hot gas, without providing a gas heating part in the carrier gas introduction pipe 10, and can give calorie | heat amount to the refrigerant | coolant in the multi air conditioner for buildings.

  As described above, in the present embodiment, when the refrigerant is sucked and collected from the refrigeration air conditioner, hot gas is introduced from the outside of the refrigeration air conditioner, and at least one of the pressure and temperature in the refrigeration air conditioner is a predetermined value. Control is performed as described above. In addition, based on at least one of the pressure and temperature in the refrigeration air conditioner, the normal recovery mode using the first refrigerant recovery path is performed in the initial recovery period, and the pressure or temperature is controlled by introducing hot gas in the second recovery period. The refrigerant recovery mode and the refrigerant recovery path are basically irreversibly switched as in the separation recovery mode using the two refrigerant recovery paths. As a result, it is possible to suppress the low-temperature condensation of the refrigerant that has occurred in the second half of the refrigerant recovery operation and to suppress a decrease in the recovery rate of the gas refrigerant. Therefore, it is possible to reduce the time for collecting the refrigerant compared to the conventional case. In addition, by increasing the temperature and pressure of the non-adsorbed gas in a compressor that circulates the non-adsorbed gas, the mixed gas of the non-adsorbed gas and the carrier gas can be turned into a hot gas. Is.

Embodiment 16 FIG.
A refrigerant recovery system and a refrigerant recovery method according to Embodiment 16 of the present invention will be described. FIG. 21 is a system diagram showing a device configuration, a control system, a flow system, and the like of the refrigerant recovery system according to the present embodiment. In addition, about the component which has the function and effect | action same as Embodiment 1-15, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  The configuration of the refrigerant recovery system according to the present embodiment will be described. The refrigerant recovery system according to the present embodiment monitors the state of the building multi-air conditioner, and is provided with a plurality of recovery modes in order to suppress a decrease in the recovery rate due to the low-temperature condensation of the refrigerant. Is almost the same. However, in the refrigerant recovery system according to the present embodiment, when the refrigerant recovery mode shifts from the normal recovery mode to the separation recovery mode, the refrigerant recovery path is also changed, and the gas separation provided in the refrigerant recovery unit The difference is that the part has a gas separation membrane. The trigger required for the transition to the refrigerant recovery mode is at least one of pressure and temperature in the building multi-air conditioner.

  In the refrigerant recovery system in the present embodiment, the refrigerant recovery path 500 is branched into two parts, a first refrigerant recovery path 400 and a second refrigerant recovery path 401, at the subsequent stage of the compressor 40. The first refrigerant recovery path 400 has substantially the same configuration as in the sixth to fifteenth embodiments, and includes a condenser 41, a refrigerant recovery container 42 and a valve 106. The second refrigerant recovery path 401 branches from the first refrigerant recovery path 400 at the front stage of the valve 106 (discharge side of the compressor 40), and the first refrigerant recovery path at the rear stage of the valve 106 (front stage of the condenser 41). 400 has joined again. In the second refrigerant recovery path 401, a valve 107, a gas separation unit 43, and a valve 108 are provided in this order in the flow direction during refrigerant recovery.

  FIG. 22 is a system diagram showing the configuration of the gas separation unit 43 of the refrigerant recovery system according to the present embodiment. The gas separation unit 43 includes a gas separation membrane 434, a separation pressure adjustment unit 435, and a separation temperature adjustment unit 436. The gas separation membrane 434 is provided with a gas inlet port 4340, a permeate gas outlet port 4341, and a non-permeate gas outlet port 4342.

  The gas inlet port 4340 of the gas separation membrane 434 is a port through which the refrigerant mixed gas sucked from the building multi-air conditioner flows, and is connected to the discharge side of the compressor 40 in the first refrigerant recovery path 400 via the valve 107. Has been. The refrigerant mixed gas flowing in through the gas inlet port 4340 is introduced into the gas separation membrane 434.

  The refrigerant mixed gas introduced into the gas separation membrane 434 is separated into a permeate gas that permeates the gas separation membrane 434 and a non-permeate gas that does not permeate the gas separation membrane 434. The permeate gas is a gas rich in the carrier gas component, and the non-permeate gas is a gas rich in the gas refrigerant component. That is, the gas separation membrane 434 has a function of separating the refrigerant mixed gas into a carrier gas component and a gas refrigerant component. The permeate gas, that is, mainly the carrier gas component, is discharged from the permeate gas outlet port 4341, and the non-permeate gas, that is, mainly the gas refrigerant component, is discharged from the non-permeate gas outlet port 4342.

  The gas separation membrane 434 has a configuration in which the separation membrane is accommodated in a metal cylindrical container. As the gas separation membrane 434, it is preferable to use a so-called molecular sieve membrane made of an inorganic material that separates substances based on a difference in molecular diameter. Although it is possible to use a separation membrane made of an organic polymer material that utilizes the difference in the permeation rate of molecules, the practical separation rate is relatively small because the difference in permeation rate between the target gas refrigerant and carrier gas in the present invention is relatively small. Can't hope. As the molecular sieve membrane, for example, one formed of alumina or zeolite is used.

  The permeated gas outlet port 4341 is a port for discharging the permeated gas that has permeated through the gas separation membrane 434, that is, a carrier gas component, and is a separation unit exhaust gas recirculation path provided with the leak concentration detection unit 7, the valve 105, and the circulation pump 12. It is connected to the carrier gas introduction pipe 10 through 505. The carrier gas component discharged from the permeate gas outlet port 4341 is sucked by the circulation pump 12 and mixed with a new carrier gas, and also inside the building multi-air conditioner via the carrier gas introduction pipe 10 and the gas heating unit 14. To be recycled. However, the gas heating unit 14 is not necessarily installed.

  The non-permeate gas outlet port 4342 is a port for discharging a non-permeate gas that does not permeate the gas separation membrane 434, that is, a gas refrigerant component, and is connected to the front stage of the condenser 41 of the first refrigerant recovery path 400 via the valve 108. Has been. The gas refrigerant component discharged from the non-permeate gas outlet port 4342 is recovered into the refrigerant recovery container 42 via the condenser 41. That is, in the present embodiment, the recovered refrigerant is accumulated only in the refrigerant recovery container 42 even when the refrigerant recovery mode is shifted.

  The separation pressure adjusting unit 435 monitors the differential pressure between the gas inlet port 4340 and the permeated gas outlet port 4341 of the gas separation membrane 434 and outputs a differential pressure detection signal to the control unit 11. The control unit 11 to which the detection signal is input controls the rotational speed of at least one of the compressor 40 and the circulation pump 12 so that a predetermined differential pressure can be maintained. For example, in order to increase the differential pressure, an operation may be performed so that one or both of the discharge pressure of the compressor 40 and the suction force of the circulation pump 12 increase. However, since the operation of the compressor 40 also affects the pressure control and the amount of carrier gas introduced in the building multi-air conditioner, it is necessary to set the operation in consideration of the entire system.

  The separation temperature adjustment unit 436 adjusts the temperature of the gas separation membrane 434 or the temperature of the gas introduced into the gas separation membrane 434. Since the gas separation membrane 434 has a structure in which the separation membrane is housed in a metal cylindrical container, the gas separation can be achieved by installing a pipe for a fluid that can flow steam or hot water, or a heater on the outer periphery of the cylindrical container. The temperature of the film 434 can be adjusted. In addition, the temperature from the gas introduced into the gas separation membrane 434 can be increased by heating the piping from the compressor 40 to the gas inlet port 4340 with the outside air or heat insulation or with a heater, and further insulating the cylindrical container with the outside air. Can also be raised. In gas separation using a separation membrane, it is generally beneficial to set the concentration, pressure and temperature of the separation target high. In the separation and recovery mode, the refrigerant concentration decreases with the recovery time, so that the separation efficiency is inevitably lowered when the gas separation conditions remain constant. Accordingly, the separation pressure adjustment unit 435 and the separation temperature adjustment unit 436 increase at least one of the pressure and the temperature via the control unit 11 according to the passage of the refrigerant concentration or the recovery time detected by the refrigerant concentration detection unit 6. Act on.

  Next, the refrigerant recovery operation in the present embodiment will be described. Before the recovery operation, the valves 100 and 106 to 108 in the refrigerant recovery unit 4 connected to the manifold 3 are closed. When starting the refrigerant recovery, the refrigerant recovery mode is set to the normal recovery mode, the compressor 40 is operated, and the valves 100 and 106 are opened. The gas refrigerant sucked into the refrigerant recovery unit 4 from the building multi-air conditioner is introduced into the first refrigerant recovery path 400. The gas refrigerant introduced into the first refrigerant recovery path 400 is increased in temperature and pressure by the compressor 40, passes through the condenser 41, and is recovered as a liquid refrigerant in the refrigerant recovery container 42. At this time, as a matter of course, the refrigerant inlet valve 420 is opened, and the non-condensed gas outlet valve 421 is closed in principle. The refrigerant recovery container 42 can be appropriately cooled, and the rise in temperature and pressure in the refrigerant recovery container 42 can be suppressed. The non-condensed gas outlet valve 421 may be appropriately opened and closed to be used for releasing the pressure in the refrigerant recovery container 42. The refrigerant recovery mode using the first refrigerant recovery path 400 corresponds to the normal recovery mode.

  As the refrigerant recovery in the normal recovery mode proceeds, the amount of refrigerant remaining in the building multi-air conditioner decreases, so the pressure in the building multi-air conditioner gradually decreases and the temperature also decreases. The pressure detection unit 5 is configured to issue an output signal to the control unit 11 once the detected pressure falls below a predetermined value. The accumulator temperature detection unit 210 is configured to issue an output signal to the control unit 11 once the detected temperature falls below a predetermined value. Note that the pressure detection unit 5 and the accumulator temperature detection unit 210 may be configured to output a detection pressure or detection temperature signal to the control unit 11 at any time, and whether the detection pressure or detection signal has fallen below a predetermined value, respectively. Of course, the controller 11 may determine whether or not. The control unit 11 performs control to change the refrigerant recovery mode of the refrigerant recovery system from the normal recovery mode to the separation recovery mode according to the input signal. Note that the transition to the refrigerant recovery mode is basically irreversible, and after changing to the separation recovery mode, the normal recovery mode is not returned until the recovery is completed.

  When receiving an output signal from at least one of the pressure detection unit 5 and the accumulator temperature detection unit 210, the control unit 11 opens the valves 107 and 108, closes the valve 106 and the refrigerant inlet valve 420, and sets the refrigerant recovery path. Is switched from the first refrigerant recovery path 400 to the second refrigerant recovery path 401. At the same time, the circulation pump 12 is operated to open the valves 101, 102, and 105, and the carrier gas is introduced from the carrier gas supply unit 8 into the building multi-air conditioner. The refrigerant recovery mode using the second refrigerant recovery path 401 and the carrier gas corresponds to the separation recovery mode.

  Since the carrier gas is introduced into the building multi-air conditioner at the start of the separation and recovery mode, the refrigerant remaining in the building multi-air conditioner becomes a mixed gas with the carrier gas. That is, the gas to be collected is diluted with the carrier gas and becomes a refrigerant mixed gas having a reduced concentration. The refrigerant mixed gas is sucked from the building multi-air conditioner by the compressor 40 and introduced into the gas separation unit 43 of the second refrigerant recovery path 401. The refrigerant mixed gas introduced into the gas separation unit 43 is separated into a gas refrigerant component (non-permeate gas) and a carrier gas component (permeate gas) by the gas separation membrane 434. The gas refrigerant component discharged from the gas separation unit 43 is recovered in the refrigerant recovery container 42 via the condenser 41. On the other hand, the carrier gas component discharged from the gas separation unit 43 is sucked by the circulation pump 12 and mixed with a new carrier gas, and is returned to the building multi-air conditioner via the carrier gas introduction pipe 10.

  That is, when the separation and recovery mode proceeds, the mixed gas of the carrier gas and the permeating gas, or the hot gas in which the mixed gas is heated through the gas heating unit 14 is recirculated into the building multi-air conditioner. It will be. Thereby, the residual refrigerant | coolant in the multi air conditioner for buildings turns into the refrigerant | coolant mixed gas diluted with the said mixed gas or hot gas. By introducing the mixed gas or hot gas, the pressure and temperature in the building multi-air conditioner do not decrease more than necessary, that is, low-temperature condensation of the refrigerant in the building multi-air conditioner is suppressed. The carrier gas introduction pipe 10 may be connected to either the gas pipe or the liquid pipe of the building multi-air conditioner, or may be connected to both the gas pipe and the liquid pipe.

  Further, the control unit 11 stores in advance as a table the relationship between the type of refrigerant, the refrigerant concentration, and the gas separation operation (temperature and pressure conditions). The control unit 11 receives the signal of the refrigerant concentration detected by the refrigerant concentration detection unit 6, and controls the separation pressure adjustment unit 435 and the separation temperature adjustment unit 436 according to the signal. Thereby, the optimal gas separation operation conditions can be maintained during the separation and recovery mode. In other words, the gas separation operation condition can be continuously and automatically followed with respect to the refrigerant concentration in the building multi-air conditioner that changes every moment by the introduction of the carrier gas, and a high gas separation rate can always be realized.

  As described above, in the present embodiment, when the refrigerant is sucked and recovered from the refrigeration air-conditioning equipment, the refrigerant recovery mode is shifted according to at least one of the pressure and temperature in the refrigeration air-conditioning equipment. Low temperature condensation accompanying suction of the refrigerant can be suppressed. Therefore, the refrigerant in the refrigerating and air-conditioning apparatus can be recovered extremely efficiently and at high speed using the gas refrigerant, and the work time related to refrigerant recovery can be greatly shortened. In addition, since a gas separation membrane is used for the gas separation unit, unlike the case where an adsorbent is used, the refrigerant in the refrigeration air conditioner can be collected in a refrigerant collection container.

Embodiment 17. FIG.
A refrigerant recovery system and a refrigerant recovery method according to Embodiment 17 of the present invention will be described. FIG. 23 is a system diagram showing an example of the configuration of the gas separation unit 43 of the refrigerant recovery system according to the present embodiment. In addition, about the component which has the function and effect | action same as Embodiment 1-16, the same code | symbol is attached | subjected and the description is abbreviate | omitted. The refrigerant recovery system according to the present embodiment is substantially the same in configuration and operation as in the sixteenth embodiment, but a plurality of gas separation membranes constituting the gas separation unit 43 are installed, and a plurality of gas separation membranes are connected in multiple stages Different in that it is.

  In the configuration shown in FIG. 23, the gas separation unit 43 has a configuration in which a first gas separation membrane 434a and a second gas separation membrane 434b are connected in two stages via a compressor 40b. In FIG. 23, the configuration in which the gas separation membranes are connected in two stages is taken as an example, but the gas separation membranes may be connected in three or more stages.

  The first gas separation membrane 434a has the same configuration as the gas separation membrane 434 of the sixteenth embodiment. That is, the first gas separation membrane 434a is provided with a gas inlet port 4340a, a permeate gas outlet port 4341a, and a non-permeate gas outlet port 4342a. Further, the first gas separation membrane 434a is provided with a separation pressure adjustment unit 435a and a separation temperature adjustment unit 436a. The gas inlet port 4340a is connected to the discharge side of the compressor 40 (see FIG. 21) via the valve 107. The non-permeate gas outlet port 4342a is connected to the upstream side of the condenser 41 via the valve 108.

  Similarly, the second gas separation membrane 434b has the same configuration as the gas separation membrane 434 of the sixteenth embodiment. That is, the second gas separation membrane 434b is provided with a gas inlet port 4340b, a permeate gas outlet port 4341b, and a non-permeate gas outlet port 4342b. In addition, the second gas separation membrane 434b is provided with a separation pressure adjustment unit 435b and a separation temperature adjustment unit 436b. The gas inlet port 4340b is connected to the permeate gas outlet port 4341a of the first gas separation membrane 434a via the compressor 40b. The non-permeate gas outlet port 4342b merges with the output side of the non-permeate gas outlet port 4342a of the first gas separation membrane 434a and is connected to the upstream side of the condenser 41 via the valve 108. The permeate gas outlet port 4341b is connected to the carrier gas introduction pipe 10 via the separation part exhaust gas recirculation path 505 provided with the leak concentration detection part 7, the valve 105 and the circulation pump 12. In the configuration shown in FIG. 23, the separation temperature adjustment unit 436a and the separation temperature adjustment unit 436b are individually provided for the first gas separation membrane 434a and the second gas separation membrane 434b. You may adjust the temperature of several gas separation membrane in an adjustment part.

  In the above configuration, the permeated gas of the first gas separation membrane 434a is an input gas that is input to the second gas separation membrane 434b through the compressor 40b. The permeated gas of the second gas separation membrane is returned to the building multi-air conditioner via the circulation pump 12. Further, the non-permeating gas of the first gas separation membrane 434a and the non-permeating gas of the second gas separation membrane 434b are merged, introduced into the condenser 41 via the valve 108, and recovered in the refrigerant recovery container 42. It has become. Since the input gas of the second gas separation membrane 434b in the second stage is the permeated gas of the first gas separation membrane 434a, the gas pressure is near atmospheric pressure. Therefore, the compressor 40b is installed before the second gas separation membrane 434b to increase the pressure of the input gas. In this system, when the refrigerant component is mixed in the permeated gas that has passed through the first gas separation membrane 434a, gas separation purification is performed again in the second gas separation membrane 434b. For this reason, mixing of the refrigerant | coolant component in permeation | transmission gas is suppressed as much as possible, and the refrigerant | coolant density | concentration in the gas introduce | transduced in the multi air conditioner for buildings can be reduced. That is, it acts to increase the purity of the refrigerant in the non-permeating gas, and the refrigerant can be recovered with higher purity.

  FIG. 24 is a system diagram showing another example of the configuration of the gas separation unit 43 of the refrigerant recovery system according to the present embodiment. In the configuration shown in FIG. 24, the gas separation unit 43 has a configuration in which a first gas separation membrane 434c and a second gas separation membrane 434d are connected in two stages. The configuration shown in FIG. 24 differs from the configuration shown in FIG. 23 in the way of connecting a plurality of gas separation membranes, but is the same in that a plurality of gas separation membranes are connected in a plurality of stages. In FIG. 24, the configuration in which the gas separation membranes are connected in two stages is taken as an example, but the gas separation membranes may be connected in three or more stages.

  The first gas separation membrane 434c and the second gas separation membrane 434d have the same configuration as the first gas separation membrane 434a and the second gas separation membrane 434b shown in FIG. The gas inlet port 4340c of the first gas separation membrane 434c is connected to the discharge side of the compressor 40 via the valve 107. The permeate gas outlet port 4341c is connected to the carrier gas introduction pipe 10 via the separation part exhaust gas recirculation path 505 provided with the leak concentration detection part 7, the valve 105 and the circulation pump 12.

  The gas inlet port 4340d of the second gas separation membrane 434d is connected to the non-permeate gas outlet port 4342c of the first gas separation membrane 434c. The permeate gas outlet port 4341d merges with the permeate gas outlet port 4341c of the first gas separation membrane 434c, and is connected to the carrier gas introduction pipe 10 via the separation part exhaust gas recirculation path 505. The non-permeate gas outlet port 4342 d is connected to the upstream side of the condenser 41 via the valve 108.

  In the configuration of this example, the separation temperature adjustment unit 436c and the separation temperature adjustment unit 436d are individually provided for the first gas separation membrane 434c and the second gas separation membrane 434d. You may adjust the temperature of several gas separation membrane. In the configuration of this example, the separation pressure adjusting unit 435c is provided only in the first gas separation membrane 434c. In the configuration of this example, since the input gas of the second gas separation membrane 434d in the second stage is a non-permeating gas of the first gas separation membrane 434c, the gas inlet port 4340d of the second gas separation membrane 434d; The non-permeate gas outlet port 4342c of the first gas separation membrane 434c is connected without a compressor or the like.

  In the above configuration, the non-permeating gas of the first gas separation membrane 434c is the input gas of the second gas separation membrane 434d. The permeated gas of the first gas separation membrane 434c and the permeated gas of the second gas separation membrane 434d are combined and recirculated into the building multi-air conditioner via the circulation pump 12. Further, the non-permeating gas of the second gas separation membrane 434d is introduced into the condenser 41 through the valve 108 and is recovered in the refrigerant recovery container 42. In this system, when the carrier gas component is mixed in the non-permeating gas that does not pass through the first gas separation membrane 434a, the gas separation purification is performed again in the second gas separation membrane 434b. For this reason, mixing of the carrier gas component into the non-permeating gas is suppressed as much as possible, and the purity of the refrigerant recovered in the refrigerant recovery container 42 can be further increased.

  As described above, in the present embodiment, when the refrigerant is sucked and recovered from the refrigeration air-conditioning equipment, the refrigerant recovery mode is shifted according to at least one of the pressure and temperature in the refrigeration air-conditioning equipment. Low temperature condensation accompanying suction of the refrigerant can be suppressed. Therefore, the refrigerant in the refrigerating and air-conditioning apparatus can be recovered extremely efficiently and at high speed using the gas refrigerant, and the work time related to refrigerant recovery can be greatly shortened. Further, by connecting gas separation membranes used in the gas separation section in multiple stages, extremely high-precision gas separation can be realized, and high-purity recovery of the refrigerant becomes possible.

Embodiment 18 FIG.
A refrigerant recovery system and a refrigerant recovery method according to Embodiment 18 of the present invention will be described. In the first to seventeenth embodiments, at least one of the determination based on the weight of the recovered refrigerant in the refrigerant recovery container or the determination based on the concentration of the refrigerant to be recovered is employed for determining whether the refrigerant recovery operation is finished. However, in Embodiments 6 to 15 using the adsorbent 430 as the gas separation unit 43, the determination method shown in the present embodiment is also effective in addition to the above-described determination method.

  In the refrigerant recovery system according to the present embodiment, the breakthrough phenomenon of the adsorbent 430 is used to determine the end of refrigerant recovery. In the separation and recovery of the refrigerant by the adsorbent 430 described in Embodiments 6 to 15, the adsorption tower 431 installed in the gas separation unit 43 is initially filled with the building multi-air conditioner to be recovered in advance. An adsorbent 430 having a weight capable of adsorbing all the refrigerant is installed. Since the adsorption amounts of various refrigerants under the individual adsorbents and adsorption conditions are determined as physical phenomena, an object to be collected is grasped in advance, and an adsorbent having a weight necessary for collecting the entire amount is prepared.

  When the adsorption of the refrigerant is dominant in the adsorbent 430, the refrigerant concentration is hardly detected by the leak concentration detector 7 that detects the refrigerant concentration leaking from the outlet of the adsorption tower 431. However, when the amount of refrigerant adsorbed on the adsorbent 430 increases and the adsorbent 430 begins to break through, the leak concentration detection unit 7 starts detecting the refrigerant concentration, and the refrigerant that could not be gradually adsorbed outside the adsorption tower 431. Leak out. Naturally, the refrigerant concentration (the refrigerant concentration leaking from the adsorption tower 431) detected by the leak concentration detector 7 is equal to or less than the atmospheric emission limit amount. In the present embodiment, since the adsorbent according to the weight of the refrigerant to be collected is installed in advance, it can be determined that the refrigerant collection operation is completed when the refrigerant concentration is detected by the leak concentration detector 7. .

  As described above, in the present embodiment, when the refrigerant is sucked and recovered from the refrigeration air-conditioning equipment, the refrigerant recovery mode is shifted according to at least one of the pressure and temperature in the refrigeration air-conditioning equipment. Low temperature condensation accompanying suction of the refrigerant can be suppressed. Therefore, the refrigerant in the refrigerating and air-conditioning apparatus can be recovered extremely efficiently and at high speed using the gas refrigerant, and the work time related to refrigerant recovery can be greatly shortened. Furthermore, since the end of the refrigerant recovery operation is determined based on the breakthrough phenomenon of the adsorbent, an extremely high refrigerant recovery rate can be achieved.

Embodiment 19. FIG.
A refrigerant recovery system and a refrigerant recovery method according to Embodiment 19 of the present invention will be described. In the above-described eighteenth embodiment, the refrigerant concentration leaking from the adsorption tower 431 is used for judging the end of refrigerant recovery by utilizing the breakthrough phenomenon of the adsorbent 430. However, in Embodiments 6 to 15 using the adsorbent 430 as the gas separation unit 43, the determination method shown in the present embodiment is also effective in addition to the above-described determination method. In the refrigerant recovery system according to the present embodiment, the heat generation phenomenon of the adsorption section in the adsorption tower 431 is used for determining the end of refrigerant recovery.

  In the separation and recovery of the refrigerant by the adsorbent 430 shown in the sixth to fifteenth embodiments, the adsorption tower 431 installed in the gas separation unit 43 is preliminarily filled with the building multi-air conditioner to be collected. An adsorbent with a weight that can absorb all of the above is installed. Since the adsorption amounts of various refrigerants under the individual adsorbents and adsorption conditions are determined as physical phenomena, an object to be collected is grasped in advance, and an adsorbent having a weight necessary for collecting the entire amount is prepared.

  The adsorption process of the refrigerant is an exothermic reaction, and in order to maintain or improve the adsorption efficiency, it is preferable to remove the generated heat and lower the temperature as much as possible. In the sixth to fifteenth embodiments, the adsorption temperature of the adsorption tower 431 is optimized by circulating a refrigerant such as water by the adsorption temperature adjusting unit 433.

  Since the adsorption of the refrigerant is an exothermic reaction, the heat generation stops when the adsorbent 430 breaks through and the adsorption reaction stops. When the adsorption temperature adjusting unit 433 as described above is used, the progress of the adsorption reaction is monitored by monitoring the refrigerant temperature difference ΔT between the outgoing line and the return line connecting the adsorption temperature adjusting unit 433 and the adsorption tower 431. Or a stop can be judged. That is, when the temperature difference ΔT falls below a predetermined value, it can be determined that the adsorption is completed, that is, the refrigerant recovery is finished.

  As described above, in the present embodiment, when the refrigerant is sucked and recovered from the refrigeration air-conditioning equipment, the refrigerant recovery mode is shifted according to at least one of the pressure and temperature in the refrigeration air-conditioning equipment. Low temperature condensation accompanying suction of the refrigerant can be suppressed. Therefore, the refrigerant in the refrigerating and air-conditioning apparatus can be recovered extremely efficiently and at high speed using the gas refrigerant, and the work time related to refrigerant recovery can be greatly shortened. Furthermore, since the end of the refrigerant recovery operation is determined based on the heat generation phenomenon of the adsorbent, an extremely high refrigerant recovery rate can be achieved.

Embodiment 20. FIG.
A refrigerant recovery system and a refrigerant recovery method according to Embodiment 20 of the present invention will be described. FIG. 25 is a system diagram showing a device configuration, a control system, a flow system, and the like of the refrigerant recovery system according to the present embodiment. In addition, about the component which has the function and effect | action same as Embodiment 1-19, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  The refrigerant recovery system according to the present embodiment has substantially the same configuration and operation as those of Embodiments 6 to 19, except that the refrigerant to be recovered is a slightly flammable or combustible refrigerant.

  When the refrigerant to be collected is slightly flammable or flammable, it is preferable not to use an electric / mechanical device such as a compressor in order to prevent an accident such as a fire. However, in order to condense or separate the recovered gas refrigerant, it is essential to increase the pressure of the gas refrigerant sucked from the building multi-air conditioner. Of course, as a compressor, there is no problem if a so-called gas compressor used for boosting corrosive gas or combustible gas is used as the compressor, but the gas compressor is extremely expensive and the apparatus size is large. Therefore, it is not suitable for refrigerant recovery work on site.

  In Embodiments 6 to 19, low temperature condensation of the refrigerant in the building multi-air conditioner is suppressed by shifting the refrigerant recovery mode according to at least one of the pressure and temperature in the building multi-air conditioner. Yes. In these embodiments, the refrigerant in the building multi-air conditioner is sucked in the normal recovery mode, and in the separation and recovery mode, the carrier gas is introduced and mixed with the refrigerant to be recovered to reduce the concentration of the refrigerant. . In other words, when the refrigerant to be collected is slightly flammable or flammable, if the refrigerant is reduced in concentration by the carrier gas that is an inert gas as in the above separation and recovery mode, the flammability of the gas collected by suction is recovered. Or it will reduce flammability and it will be possible to use a compressor.

  FIG. 25 shows an example in which the present embodiment is applied to a configuration in which a gas separation unit 43 using an adsorbent is provided. In the refrigerant recovery system shown in FIG. 25, the refrigerant recovery path 500 is branched after the refrigerant concentration detector 6. One refrigerant path is a bypass path 402 and is connected to the ejector 120 via a valve 114. Here, the ejector 120 is more preferably made of resin. The other refrigerant path is a refrigerant recovery path 403, and is connected to the compressor 40 of the refrigerant recovery unit 4 via the valve 100. That is, the bypass path 402 branches off from the refrigerant recovery paths 500 and 403 at the front stage of the compressor 40. The downstream side of the compressor 40 in the refrigerant recovery path 403 joins the downstream side of the valve 114 in the bypass path 402 via the valve 107, the gas separation unit 43, the valve 108, the leak concentration detection unit 7, and the valve 105. Yes. The valves 100 and 114 function as route switching means for switching the route between the bypass route 402 and the refrigerant recovery route 403. As the path switching means, a three-way valve or the like can be used instead of the valves 100 and 114.

  Refrigerant recovery begins by using the bypass path 402 to lower the concentration of the refrigerant in the building multi-air conditioner with the carrier gas. The mixed gas of the refrigerant and the carrier gas is sucked and circulated by the ejector 120. This mode is referred to as “bypass mode”. In the bypass mode, the valve 114 of the bypass path 402 is open, the valves 100, 107, 108, and 105 of the refrigerant recovery path 403 are closed, and the compressor 40 is stopped. In the bypass mode, the flow rate adjusting unit 9 and the gas heating unit 14 are controlled such that at least one of the pressure and temperature in the building multi-air conditioner is maintained at a predetermined value or more. In the bypass mode, when the carrier gas is introduced, the refrigerant concentration of the refrigerant mixed gas in the building multi-air conditioner decreases. After the refrigerant concentration detected by the refrigerant concentration detection unit 6 falls below a predetermined concentration, the mode shifts from the bypass mode to the separation recovery mode (refrigerant recovery mode).

  In the separation and recovery mode, the valve 114 of the bypass path 402 is closed, the valves 100, 107, 108, and 105 of the refrigerant recovery path 403 are opened, and the refrigerant path is switched. In the separation and recovery mode, the compressor 40 operates. The refrigerant mixed gas whose concentration is reduced in the bypass mode is introduced into the refrigerant recovery unit 4 via the refrigerant recovery path 403, and refrigerant recovery is started. In the gas separation unit 43 provided in the refrigerant recovery unit 4, the refrigerant component and other components (non-adsorbed gas) are separated, and the refrigerant component is selectively adsorbed and recovered. The separated non-adsorbed gas is sucked by the ejector 120, mixed with a newly introduced carrier gas, and returned to the building multi-air conditioner. Therefore, in this embodiment, electric power is not required for circulation of the non-adsorbed gas and the carrier gas. If the refrigerant concentration detected by the refrigerant concentration detector 6 rises above the predetermined concentration during the separation / recovery mode, the process returns to the bypass mode, and the refrigerant concentration is reduced again. Again, the separation and recovery mode can be restored. That is, the transition from the bypass mode to the separation and recovery mode in the present embodiment is not necessarily irreversible. Although the case where an adsorbent is used as the gas separation unit 43 has been described here, the same effect can be obtained when a gas separation membrane is used. In addition, the present embodiment is extremely effective for a slightly flammable or combustible refrigerant, but it can be used for recovery of other refrigerants, that is, the refrigerants targeted in the first to the nineteenth embodiments. is there.

  As described above, in the present embodiment, when the refrigerant is sucked and collected from the refrigeration air conditioner, hot gas is introduced from the outside of the refrigeration air conditioner, and at least one of the pressure and temperature in the refrigeration air conditioner is a predetermined value. Control is performed as described above. Further, before the refrigerant to be collected is sucked into the refrigerant collecting unit and collected, the concentration of the refrigerant to be collected is reduced by the bypass mode. After the concentration of the refrigerant to be collected is reduced by the bypass mode, the mode is shifted to the separation and collection mode, and the refrigerant is collected. For this reason, it is possible to suppress the low-temperature condensation of the refrigerant that has occurred in the second half of the refrigerant recovery operation and to suppress the reduction in the recovery rate of the gas refrigerant. Therefore, it is possible to reduce the time for collecting the refrigerant compared to the conventional case. Further, since the non-adsorbed gas is mixed with the carrier gas by the ejector and recirculated into the building multi-air conditioner, power such as a pump is not required, which is economical. Further, since there is no electrical / mechanical device that contacts the high-concentration refrigerant in the recovery path, it can be used for a slightly flammable or flammable refrigerant.

  The refrigerant recovery system and the refrigerant recovery method according to each of the above embodiments are summarized as follows.

  The refrigerant recovery system according to the above embodiment includes a refrigerant recovery path 500 for recovering gas refrigerant in the refrigeration air conditioning equipment, a carrier gas introduction path 502 for introducing carrier gas into the refrigeration air conditioning equipment, and a pressure in the refrigeration air conditioning equipment. And a detection unit (for example, pressure detection unit 5) that detects at least one of temperature and a control unit 11 that performs control based on at least one of pressure and temperature, and the refrigerant recovery path 500 sucks gas refrigerant. A compressor 40 that compresses the gas refrigerant, a condenser 41 that condenses the gas refrigerant compressed by the compressor 40 into a liquid refrigerant, and a refrigerant recovery container 42 that recovers the liquid refrigerant condensed by the condenser 41. The carrier gas introduction path 502 includes a carrier gas supply unit 8 that supplies the carrier gas, and a flow rate adjustment that adjusts the flow rate of the carrier gas introduced into the refrigeration air conditioner. Means (for example, a valve 101 and a flow rate adjusting unit 9), and the control unit 11 controls the flow rate adjusting unit so that at least one of pressure and temperature is maintained at a predetermined value or more. And

  The refrigerant recovery system according to the above-described embodiment is provided between the refrigerant recovery container 42 and the carrier gas introduction path 502, and exhaust gas discharged from the refrigerant recovery container 42 is transferred to the carrier in the carrier gas introduction path 502. The apparatus further includes a container exhaust gas recirculation path 503 that joins the gas and recirculates the gas into the refrigeration air conditioner.

  Further, in the refrigerant recovery system according to the above-described embodiment, the refrigerant recovery path 500 is branched into the first refrigerant recovery path 400 and the second refrigerant recovery path 401 at the rear stage of the compressor 40, and the first refrigerant recovery path 400 includes a condenser 41 and a refrigerant recovery container 42, and the second refrigerant recovery path 401 separates the gas refrigerant component from the mixed gas containing the gas refrigerant compressed by the compressor 40, and the remainder. Is provided with a path switching means (for example, valves 106 and 107) for switching the path between the first refrigerant recovery path 400 and the second refrigerant recovery path 401. The unit 11 switches the path from the first refrigerant recovery path 400 to the second refrigerant recovery path 401 when at least one of the pressure and temperature falls below a predetermined value.

  The refrigerant recovery system according to the above embodiment is provided between the gas separation unit 43 and the carrier gas introduction path 502, and the remaining gas components discharged from the gas separation unit 43 are transferred to the carrier in the carrier gas introduction path 502. It is further characterized by further comprising a separation section exhaust gas recirculation path 505 that is combined with gas and recirculated into the refrigeration air conditioner.

  The refrigerant recovery system according to the above embodiment is characterized in that the gas separation unit 43 includes an adsorbent 430.

  The refrigerant recovery system according to the above embodiment is characterized in that the gas separation unit 43 includes a gas separation membrane 434.

  In addition, the refrigerant recovery system according to the above-described embodiment further includes a gas heating unit 14 that is provided in the carrier gas introduction path 502 and that heats the gas introduced into the refrigerating and air-conditioning equipment.

  In the refrigerant recovery system according to the above-described embodiment, the control unit 11 includes the normal recovery mode for recovering the gas refrigerant in the refrigeration air conditioner without introducing the carrier gas into the refrigeration air conditioner, and the refrigeration air conditioner. A separation recovery mode for recovering the gas refrigerant in the refrigerating and air-conditioning equipment while introducing the carrier gas, and the control unit 11 is normally triggered when at least one of the pressure and the temperature falls below a predetermined value. It is characterized by shifting from the recovery mode to the separation / recovery mode.

  The refrigerant recovery system according to the above embodiment includes refrigerant recovery paths 500 and 403 for recovering gas refrigerant in the refrigeration and air conditioning equipment, a carrier gas introduction path 502 for introducing carrier gas into the refrigeration and air conditioning equipment, and refrigeration and air conditioning. A detection unit (for example, pressure detection unit 5) that detects at least one of pressure and temperature in the device, a refrigerant concentration detection unit 6 that detects refrigerant concentration in the refrigeration air-conditioning device, at least one of pressure and temperature, and refrigerant concentration A control unit 11 that performs control based on the above, and the refrigerant recovery paths 500 and 403 include a compressor 40 that sucks and compresses the gas refrigerant, and a mixed gas containing the gas refrigerant compressed by the compressor 40. And a gas separation unit 43 that separates and collects the gas refrigerant component and discharges the remaining gas component. A carrier gas supply path 502 is provided with a key for supplying the carrier gas. The rear gas supply unit 8 and flow rate adjusting means (for example, the valve 101 and the flow rate adjusting unit 9) for adjusting the flow rate of the carrier gas introduced into the refrigeration and air conditioning equipment are provided. The former stage of the compressor 40 and the carrier gas introduction path 502 are connected, and the gas refrigerant in the refrigerating and air-conditioning equipment is merged with the carrier gas in the carrier gas introduction path 502 without passing through the compressor 40, thereby The apparatus further includes a bypass path 402 for refluxing into the device, and path switching means (for example, valves 100 and 114) for switching the path between the refrigerant recovery path 403 and the bypass path 402, and the control unit 11 includes at least a pressure and a temperature. The flow rate adjusting means is controlled so that one is maintained at a predetermined value or more, and the control unit 11 is configured so that the refrigerant concentration falls below the predetermined concentration. And it switches the path to the refrigerant collection path 403 from bypass passage 402.

  The refrigerant recovery system according to the above embodiment is characterized in that the refrigerant is slightly flammable or flammable.

  The refrigerant recovery method according to the above embodiment includes a refrigerant recovery path 500 that recovers gas refrigerant in the refrigeration air conditioning equipment, a carrier gas introduction path 502 that introduces carrier gas into the refrigeration air conditioning equipment, and the inside of the refrigeration air conditioning equipment. A detection unit (for example, pressure detection unit 5) that detects at least one of the pressure and the temperature of the gas, and a refrigerant recovery path 500 that includes a compressor 40 that sucks and compresses the gas refrigerant, and a compressor 40 that compresses the refrigerant. A condenser 41 for condensing the gas refrigerant into a liquid refrigerant, and a refrigerant recovery container 42 for recovering the liquid refrigerant condensed in the condenser 41. A carrier gas is introduced into the carrier gas introduction path 502. A carrier gas supply unit 8 to be supplied and a flow rate adjusting means (for example, a valve 101 and a flow rate adjusting unit 9) for adjusting the flow rate of the carrier gas introduced into the refrigeration air conditioner are provided. A refrigerant recovery method for use in a refrigerant recovery system are, at least one of pressure and temperature and introducing a carrier gas into the refrigeration and air conditioning equipment to be maintained above a predetermined value.

  In the refrigerant recovery method according to the above embodiment, the refrigerant recovery path 500 is branched into the first refrigerant recovery path 400 and the second refrigerant recovery path 401 after the compressor 40, and the first refrigerant recovery path 400 includes a condenser 41 and a refrigerant recovery container 42, and the second refrigerant recovery path 401 separates the gas refrigerant component from the mixed gas containing the gas refrigerant compressed by the compressor 40, and the remainder. The gas separation unit 43 for discharging the gas components of the refrigerant is provided, and the refrigerant recovery system is a path switching means (for example, valves 106 and 107) for switching the path between the first refrigerant recovery path 400 and the second refrigerant recovery path 401. And switching the path from the first refrigerant recovery path 400 to the second refrigerant recovery path 401 when at least one of the pressure and temperature falls below a predetermined value. To.

  In addition, the refrigerant recovery method according to the above embodiment includes refrigerant recovery paths 500 and 403 for recovering gas refrigerant in the refrigeration and air conditioning equipment, a carrier gas introduction path 502 for introducing carrier gas into the refrigeration and air conditioning equipment, and refrigeration and air conditioning. A refrigerant recovery path 500, 403 includes a detection unit (for example, a pressure detection unit 5) that detects at least one of pressure and temperature in the device, and a refrigerant concentration detection unit 6 that detects the refrigerant concentration in the refrigeration and air conditioning device. Includes a compressor 40 that sucks and compresses gas refrigerant, and a gas separation unit that separates and recovers the gas refrigerant component from the mixed gas containing the gas refrigerant compressed by the compressor 40 and discharges the remaining gas component 43, and the carrier gas introduction path 502 adjusts the flow rate of the carrier gas supplied into the refrigeration and air-conditioning equipment and the carrier gas supply unit 8 for supplying the carrier gas. An amount adjusting means (for example, a valve 101, a flow rate adjusting unit 9), and connecting between a stage before the compressor 40 of the refrigerant recovery paths 500 and 403 and the carrier gas introduction path 502, and A bypass path 402 that causes the gas refrigerant in the air conditioning equipment to merge with the carrier gas in the carrier gas introduction path 502 without passing through the compressor 40 and recirculates the refrigerant into the refrigeration air conditioning equipment. A refrigerant recovery method used in a refrigerant recovery system further comprising a path switching means (for example, valves 100 and 114) for switching between the refrigeration and air conditioning equipment so that at least one of pressure and temperature is maintained at a predetermined value or more. After the carrier gas is introduced and the refrigerant concentration falls below the predetermined concentration, the route is switched from the bypass route 402 to the refrigerant recovery route 403. And wherein the frog.

The present invention is not limited to the above embodiment, and various modifications can be made.
For example, in the above embodiment, the flow rate of the gas introduced into the building multi-air conditioner in the separation and recovery mode is adjusted based on the pressure in the building multi-air conditioner. It may be adjusted based on the above, or may be adjusted based on both the pressure and temperature in the building multi-air conditioner.

  In addition, the above embodiments and modifications can be implemented in combination with each other.

  1 indoor unit, 2 outdoor unit, 3 manifold, 4 refrigerant recovery unit, 5 pressure detection unit, 6 refrigerant concentration detection unit, 7 leak concentration detection unit, 8 carrier gas supply unit, 9 flow rate control unit, 10 carrier gas introduction pipe, DESCRIPTION OF SYMBOLS 11 Control part, 12 Circulation pump, 13 Flow sensor, 14 Gas heating part, 15 Buffer tank, 16 Heat exchanger, 20 Four-way valve, 21 Accumulator, 22 Compressor, 23 Outdoor heat exchanger, 25 Liquid piping, 26 Gas Piping, 40, 40b Compressor, 41 Condenser, 42 Refrigerant recovery container, 43 Gas separation unit, 44 Commercial refrigerant recovery device, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110 , 111, 112, 113, 114 Valve, 120 Ejector, 121 Compressor for circulation, 200 High-pressure side service port 201 low pressure side service port, 210 accumulator temperature detection unit, 300 branching unit, 301 junction, 400 first refrigerant recovery path, 401 second refrigerant recovery path, 402 bypass path, 403 refrigerant recovery path, 420 refrigerant inlet valve, 421 Non-condensed gas outlet valve, 430 adsorbent, 431 adsorption tower, 432 adsorption pressure adjustment unit, 433 adsorption temperature adjustment unit, 434 gas separation membrane, 434a, 434c first gas separation membrane, 434b, 434d second gas separation membrane, 435 435a, 435b, 435c separation pressure adjustment unit, 436, 436a, 436b, 436c, 436d separation temperature adjustment unit, 500 refrigerant recovery path, 501 non-condensable gas discharge path, 502 carrier gas introduction path, 503 container exhaust gas recirculation path, 504 Mixed gas discharge path, 505 Away portion exhaust gas recirculation passage, 4340,4340a, 4340b, 4340c, 4340d gas inlet port, 4341,4341a, 4341b, 4341c, 4341d permeate gas outlet port, 4342,4342a, 4342b, 4342c, 4342d non-permeate gas outlet port.

Claims (13)

A refrigerant recovery path for recovering the gas refrigerant in the refrigerating and air-conditioning equipment;
A carrier gas introduction path for introducing a carrier gas into the refrigeration air conditioner;
A detection unit for detecting at least one of pressure and temperature in the refrigeration air conditioner;
A control unit that performs control based on at least one of the pressure and temperature,
In the refrigerant recovery path,
A compressor that sucks and compresses the gas refrigerant;
A condenser for condensing the gas refrigerant compressed by the compressor into a liquid refrigerant;
A refrigerant recovery container for recovering the liquid refrigerant condensed by the condenser, and
In the carrier gas introduction path,
A carrier gas supply unit for supplying the carrier gas;
A flow rate adjusting means for adjusting the flow rate of the carrier gas introduced into the refrigeration air conditioner, and
The said control part controls the said flow volume adjustment means so that at least one of the said pressure and temperature may maintain more than predetermined value, The refrigerant | coolant collection system characterized by the above-mentioned.   Provided between the refrigerant recovery container and the carrier gas introduction path, the exhaust gas discharged from the refrigerant recovery container merges with the carrier gas in the carrier gas introduction path and is returned to the refrigeration air conditioner The refrigerant recovery system according to claim 1, further comprising a first exhaust gas recirculation path to be made. The refrigerant recovery path is branched into a first refrigerant recovery path and a second refrigerant recovery path after the compressor,
The first refrigerant recovery path is provided with the condenser and the refrigerant recovery container,
The second refrigerant recovery path is provided with a gas separation unit that separates a gas refrigerant component from a mixed gas containing the gas refrigerant compressed by the compressor and discharges the remaining gas component,
Path switching means for switching the path between the first refrigerant recovery path and the second refrigerant recovery path;
2. The control unit according to claim 1, wherein the control unit switches the path from the first refrigerant recovery path to the second refrigerant recovery path when at least one of the pressure and temperature falls below the predetermined value. The refrigerant recovery system described.   It is provided between the gas separation unit and the carrier gas introduction path, and the remaining gas component discharged from the gas separation part is merged with the carrier gas in the carrier gas introduction path into the refrigeration air conditioner. The refrigerant recovery system according to claim 3, further comprising a second exhaust gas recirculation path for recirculation.   The refrigerant recovery system according to claim 3 or 4, wherein the gas separation unit includes an adsorbent.   The refrigerant recovery system according to claim 3 or 4, wherein the gas separation unit includes a gas separation membrane.   The gas heater according to claim 1, further comprising a gas heating unit that is provided in the carrier gas introduction path and that heats the gas introduced into the refrigeration air conditioner. Refrigerant recovery system. The control unit is configured to recover the gas refrigerant in the refrigeration air conditioner without introducing the carrier gas into the refrigeration air conditioner, and to introduce the carrier gas into the refrigeration air conditioner. A second recovery mode for recovering the gas refrigerant in the refrigerating and air-conditioning equipment,
The control unit shifts from the first recovery mode to the second recovery mode when at least one of the pressure and temperature falls below the predetermined value. The refrigerant recovery system according to any one of the above. A refrigerant recovery path for recovering the gas refrigerant in the refrigerating and air-conditioning equipment;
A carrier gas introduction path for introducing a carrier gas into the refrigeration air conditioner;
A detection unit for detecting at least one of pressure and temperature in the refrigeration air conditioner;
A refrigerant concentration detector for detecting the refrigerant concentration in the refrigeration and air conditioning equipment;
A controller that performs control based on at least one of the pressure and temperature and the refrigerant concentration,
In the refrigerant recovery path,
A compressor that sucks and compresses the gas refrigerant;
A gas separation unit that separates and recovers a gas refrigerant component from the mixed gas containing the gas refrigerant compressed by the compressor and discharges the remaining gas component; and
In the carrier gas introduction path,
A carrier gas supply unit for supplying the carrier gas;
A flow rate adjusting means for adjusting the flow rate of the carrier gas introduced into the refrigeration air conditioner, and
The refrigerant recovery path is connected between the front stage of the compressor and the carrier gas introduction path, and the gas refrigerant in the refrigerating and air-conditioning apparatus is not routed through the compressor without passing through the compressor. A bypass path that merges with the carrier gas and recirculates into the refrigerating and air-conditioning equipment;
Path switching means for switching the path between the refrigerant recovery path and the bypass path; and
The control unit controls the flow rate adjusting means so that at least one of the pressure and temperature is maintained at a predetermined value or more,
The said control part switches a path | route from the said bypass path | route to the said refrigerant | coolant collection path | route after the said refrigerant | coolant density | concentration falls below predetermined density | concentration, The refrigerant | coolant collection system characterized by the above-mentioned.   The refrigerant recovery system according to claim 9, wherein the refrigerant is slightly flammable or flammable. A refrigerant recovery path for recovering the gas refrigerant in the refrigerating and air-conditioning equipment;
A carrier gas introduction path for introducing a carrier gas into the refrigeration air conditioner;
A detection unit that detects at least one of pressure and temperature in the refrigeration air conditioner,
In the refrigerant recovery path,
A compressor that sucks and compresses the gas refrigerant;
A condenser for condensing the gas refrigerant compressed by the compressor into a liquid refrigerant;
A refrigerant recovery container for recovering the liquid refrigerant condensed by the condenser, and
In the carrier gas introduction path,
A carrier gas supply unit for supplying the carrier gas;
A flow rate adjusting means for adjusting the flow rate of the carrier gas introduced into the refrigeration air conditioner, and a refrigerant recovery method used in a refrigerant recovery system provided with
A refrigerant recovery method, wherein the carrier gas is introduced into the refrigeration / air-conditioning apparatus so that at least one of the pressure and temperature is maintained at a predetermined value or more. The refrigerant recovery path is branched into a first refrigerant recovery path and a second refrigerant recovery path after the compressor,
The first refrigerant recovery path is provided with the condenser and the refrigerant recovery container,
The second refrigerant recovery path is provided with a gas separation unit that separates a gas refrigerant component from a mixed gas containing the gas refrigerant compressed by the compressor and discharges the remaining gas component,
The refrigerant recovery system further includes path switching means for switching a path between the first refrigerant recovery path and the second refrigerant recovery path,
The refrigerant recovery method according to claim 11, wherein the path is switched from the first refrigerant recovery path to the second refrigerant recovery path when at least one of the pressure and temperature falls below the predetermined value. . A refrigerant recovery path for recovering the gas refrigerant in the refrigerating and air-conditioning equipment;
A carrier gas introduction path for introducing a carrier gas into the refrigeration air conditioner;
A detection unit for detecting at least one of pressure and temperature in the refrigeration air conditioner;
A refrigerant concentration detector that detects the refrigerant concentration in the refrigeration air conditioner, and
In the refrigerant recovery path,
A compressor that sucks and compresses the gas refrigerant;
A gas separation unit that separates and recovers a gas refrigerant component from the mixed gas containing the gas refrigerant compressed by the compressor and discharges the remaining gas component; and
In the carrier gas introduction path,
A carrier gas supply unit for supplying the carrier gas;
A flow rate adjusting means for adjusting the flow rate of the carrier gas introduced into the refrigeration air conditioner, and
The refrigerant recovery path is connected between the front stage of the compressor and the carrier gas introduction path, and the gas refrigerant in the refrigerating and air-conditioning apparatus is not routed through the compressor without passing through the compressor. A bypass path that merges with the carrier gas and recirculates into the refrigerating and air-conditioning equipment;
A refrigerant recovery method for use in a refrigerant recovery system, further comprising: path switching means for switching between the refrigerant recovery path and the bypass path;
Introducing the carrier gas into the refrigeration air conditioner so that at least one of the pressure and temperature is maintained at a predetermined value or higher,
A refrigerant recovery method comprising switching the path from the bypass path to the refrigerant recovery path after the refrigerant concentration falls below a predetermined concentration.

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