JP2009085480A - Absorption type refrigerating device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the efficiency of a cold use-side device by lowering a temperature of a cooled fluid at an outlet of an evaporator to a limit while preventing the freezing of a refrigerant, in an absorption type refrigerating device driven by the exhaust heat of an engine by lowering the temperature of the cooled fluid at the outlet of the evaporator to the limit while preventing the freezing of the refrigerant. <P>SOLUTION: In this exhaust heat-driven absorption type refrigerating device, a refrigerating capacity is controlled by changing a temperature of a supercooled solution flowing to an absorber and/or a flow rate of the supercooled solution, the flow of the refrigerant to the evaporator is stopped when the temperature of the cooled fluid at the outlet of the evaporator reaches a prescribed temperature or lower, the refrigerant is allowed to flow into the evaporator when the temperature reaches the prescribed temperature or higher, and the refrigerant directly flows to a dilute solution reservoir at a lower portion of the absorber during the stop of the flow of the refrigerant. According to this constitution, the temperature of the cooled fluid can be lowered to the limit and the performance of the cold use-side device can be improved to the maximum while preventing the freezing of the refrigerant. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an absorption refrigeration apparatus driven by engine exhaust heat.

  The conventional air-cooled absorption refrigeration system is a direct air-cooling method in which the solution is cooled by air-cooling fins while absorbing the refrigerant vapor by the absorber, and the absorber absorbs the refrigerant vapor and cools the absorbed solution at the same time. Expansion of the gas-liquid interface is important for performance improvement. However, for that purpose, large-diameter heat transfer tubes for reducing the pressure loss of the refrigerant vapor absorbed by the solution flowing on the upper and lower absorber headers and the wall of the absorber heat transfer tube, and the large size of the refrigerant vapor communication tube with the evaporator are used. It is necessary to reduce the diameter of the device, and there is a great restriction on downsizing the device.

  On the other hand, the solution flowing into the absorber is supercooled by an air-cooled cooler, and the refrigerant heat is simply absorbed in the absorber, and the absorbed heat is removed by sensible heat of the supercooled solution (solution The separation cooling method is considered to be the most advantageous method for a small air-cooled absorption refrigeration apparatus because the absorber is made smaller than before.

  If this indirect air-cooled air-cooled absorption refrigeration system is driven by using exhaust heat from the engine, the size and cost of the apparatus can be reduced. It can be easily changed to a form to be converted to use, the effective use of exhaust heat is promoted, and it can be considered that it can greatly contribute to energy saving and CO2 reduction.

  By the way, as a conventional example of this indirect air cooling type air cooling absorption refrigeration apparatus, for example, there is one disclosed in Patent Document 1, but in this conventional example, an absorber is a type that sprays a solution. Although it is adopted, it is a conventional direct-fire method in which a solution is heated by a burner with a double-effect cycle, and there is no example using exhaust heat.

  Also, the compression refrigeration unit is driven by the engine, the absorption refrigeration unit is driven by the exhaust heat, and the refrigerant of the compression refrigeration unit is supercooled by the cold heat so that the performance of the compression refrigeration unit is improved. As a conventional example of a refrigeration system in which an absorption refrigeration apparatus and a compression refrigeration apparatus are combined, there are many examples such as that shown in Patent Document 2, for example.

JP-A-7-98163 JP-A-9-53864

  By the way, in a system combining a compression refrigeration apparatus driven by an engine and an absorption refrigeration apparatus driven by the exhaust heat, in the above-described conventional example, the cooling heat of the absorption refrigeration apparatus that simply uses the exhaust heat. Thus, the refrigerant of the compression refrigeration apparatus is supercooled.

  However, when the outside air temperature decreases or when the compression refrigeration apparatus becomes a partial load, the refrigerant temperature (that is, the condensation temperature) at the condenser outlet of the compression refrigeration apparatus decreases. When the temperature drop and the partial load of the compression refrigeration unit overlap, the refrigerant temperature drop at the outlet of the condenser of this compression refrigeration unit becomes large. The temperature range in which the refrigerant can be supercooled is reduced, and the performance improvement rate of the compression refrigeration apparatus by supercooling the refrigerant of the compression refrigeration apparatus is greatly reduced. As a result, there is a problem that the running cost of the engine-driven compression refrigeration apparatus is less effective than the initial cost of the absorption refrigeration apparatus in the cold utilization period (that is, the cooling operation period of the compression refrigeration apparatus). There is.

  Furthermore, when the generator is driven by the engine and the absorption refrigeration device is driven by the exhaust heat to use the cold heat, in particular, the compression refrigeration device is driven by the engine as described above and absorbed by the exhaust heat. In a system or the like that drives a refrigerating device and supercools the refrigerant of the compression refrigerating device with the cold heat obtained by the absorption refrigerating device to improve the performance of the refrigerating device, it is discharged from the heat source side Stopping heat exhaust just for the equipment side that uses exhaust heat (exhaust heat absorption refrigeration system) has a large effect on the heat source side (engine use side equipment). It is also a difficult thing to have, except in an emergency.

  In addition, as control of the amount of exhaust heat, the output of the absorption refrigeration system is detected by the temperature difference between the outlet and the outlet of the cooled fluid in the evaporator, and the amount of hot water flowing into the generator of the absorption refrigeration system (exhaust heat amount) The conventional system that controls the three-way valve in accordance with the output (refrigeration load) of the absorption refrigeration system requires that a three-way valve, etc. be built into the heat source side device from the beginning, and is more expensive. Before that, it is not the control with the evaporator or the absorber that is directly linked to the capacity control of the absorption refrigeration system, but the control with the generator, so there is only a time lag in the control. However, the control of the refrigerating capacity of the absorption refrigeration system under a condition where the refrigerant condensing temperature of the compression refrigeration system is low, such as when the outside air temperature is low or when the compression refrigeration apparatus is partially loaded, requires a considerable temperature margin. Therefore, the temperature of the cooled fluid of the evaporator of the absorption refrigeration system (that is, the supercooling temperature of the refrigerant of the compression refrigeration system) must be set to the limit value (that is, LiBr as the absorption liquid and water as the refrigerant). Therefore, the temperature range at which the refrigerant of the compression refrigeration system can be supercooled is reduced by the amount set higher, and the absorption type The performance improvement effect of the compression refrigeration apparatus due to the supercooling of the refrigerant of the compression refrigeration apparatus by the cold heat of the refrigeration apparatus has also been a factor that diminishes.

  From these facts, it can be said that it is effective to reduce the degree of supercooling of the refrigerant to the limit in order to improve the efficiency of the compression refrigeration apparatus.

  However, if the degree of supercooling of the refrigerant of the compression refrigeration system is reduced to the limit and the efficiency of the compression refrigeration system is improved as much as possible, the outside air temperature and the load of the engine driven compression refrigeration system will decrease. In such a case, even if the capacity of the absorption refrigeration system is controlled to the minimum, the refrigeration capacity of the time lag or the absorption refrigeration system may be excessive and the refrigerant (water) flowing into the evaporator may freeze. Therefore, it is necessary to quickly reduce the capacity of the absorption refrigeration apparatus, and this point needs to be taken into consideration.

  Accordingly, the present invention is an absorption refrigeration apparatus driven by engine exhaust heat so that the temperature of the fluid to be cooled at the evaporator outlet can be lowered to the limit while avoiding freezing of the refrigerant, thereby absorbing the absorption refrigeration. It was made for the purpose of improving the efficiency of the cold energy utilization side equipment that utilizes the cold energy of the apparatus.

  In the present invention, the following configuration is adopted as a specific means for solving such a problem.

  In the first invention of the present application, a generator driven by exhaust heat of the engine, a condenser, a falling liquid film type absorber, an air-cooled supercooler for supercooling the absorbing solution entering the absorber, In an exhaust heat-driven absorption refrigeration apparatus including an evaporator that is housed in a housing integral with the absorber and evaporates the refrigerant in a transient manner, the temperature and / or excess temperature of the supercooled solution flowing into the absorber. The refrigeration capacity of the absorption refrigeration system is controlled by changing the flow rate of the cooling solution, and when the temperature of the fluid to be cooled at the outlet of the evaporator is equal to or lower than a predetermined temperature, the condenser is changed to the evaporator. The refrigerant solenoid valve provided in the piping to be closed is closed to stop the flow of refrigerant into the evaporator, and when the temperature exceeds a predetermined temperature, the refrigerant solenoid valve is opened and the evaporator is connected to the evaporator from the condenser. The refrigerant solenoid valve allows the refrigerant to flow in. During the closing operation is characterized in that to flow into the reservoir dilute solution directly to the absorber bottom of the refrigerant from the condenser.

According to this configuration,
(1) Since the refrigeration capacity of the absorption refrigeration system is controlled by changing the supercooling temperature and / or flow rate of the supercooled absorption solution flowing into the absorber, There is no time lag in the control like the control that increases or decreases the refrigerant generation amount in the generator by the heat input control and increases or decreases the refrigerating capacity of the absorption refrigeration system, and the control of increasing or decreasing the refrigerating capacity is quick with good responsiveness (2) When the temperature of the fluid to be cooled at the outlet of the evaporator is controlled to a low temperature by the absorption refrigeration apparatus, and further falls below a predetermined temperature, the evaporator The refrigerant flowing into the refrigerant may freeze, but at this time, the refrigerant electromagnetic valve provided in the pipe from the condenser to the evaporator is closed to stop the refrigerant from flowing into the evaporator. It is possible to prevent the refrigerant from rapidly freeing and freezing the refrigerant, and when the temperature is equal to or higher than a predetermined temperature and there is no possibility that the refrigerant freezes, the refrigerant electromagnetic valve is opened and the evaporator is connected to the evaporator. Refrigeration capacity can be improved by injecting refrigerant from
As a synergistic effect, it is possible to reduce the temperature of the fluid to be cooled to the limit while preventing the refrigerant from freezing, and to improve the performance of the cold energy utilization side device to the maximum extent.

  Further, while the refrigerant solenoid valve is closed, the refrigerant from the condenser is caused to flow into the dilute solution reservoir below the absorber, thereby preventing change in the concentration of the solution and increasing the absorption capacity in the absorber. This prevents the refrigerant from freezing more easily.

  In the second invention of the present application, in the absorption refrigeration apparatus according to the first invention, the refrigeration capacity of the absorption refrigeration apparatus is calculated by calculating the deviation between the temperature of the fluid to be cooled and the target temperature at the outlet of the evaporator, or It is characterized by the deviation between the temperature difference of the fluid to be cooled at the outlet and the inlet of the evaporator and the target temperature difference.

  Here, the “target temperature” or “target temperature difference” is the temperature or temperature difference based on the operating state of the cold energy utilization side device (for example, the outside air temperature when the cold energy utilization side device is a compression refrigeration apparatus). The temperature after the supercooling of the compression refrigerant set according to the operating load or the temperature difference of the supercooling). Therefore, the refrigerating capacity of the absorption refrigeration system is restricted to the capacity corresponding to this "deviation between the temperature of the fluid to be cooled and the target temperature" or "deviation between the temperature difference of the fluid to be cooled and the target temperature difference". Thus, the excessive refrigeration capacity can reliably prevent, for example, the temperature of the fluid to be cooled further lower than the target temperature and freezing of the refrigerant.

  In a third invention of the present application, in the absorption refrigeration apparatus according to the first or second invention, the predetermined temperature is equal to or lower than a target temperature of a fluid to be cooled at an outlet of the evaporator. It is characterized by being set to.

  Here, the “target temperature” is a target temperature at the time of operation of the cold energy utilization side device, and the “temperature lower than the target temperature” is a limit temperature that is lower than the target temperature. Therefore, the above-mentioned “predetermined temperature”, that is, the limit temperature that may cause the refrigerant to freeze is “set to a temperature that is equal to or lower than the target temperature”, so that the capacity of the cold-use side device is used to the limit. can do.

  According to a fourth invention of the present application, in the absorption refrigeration apparatus according to the first, second or third invention, the air flows into the absorber by the start / stop of a fan provided in the air-cooled supercooler or the increase / decrease of the air volume. The refrigerating capacity is controlled by changing the temperature of the supercooled solution.

  According to such a configuration, the control of the refrigerating capacity by changing the temperature of the supercooled solution can be performed very easily and quickly by making use of the characteristics of the indirect air cooling system and by the start / stop of the fan or the increase / decrease of the air volume. The capacity control range of the absorption refrigeration apparatus can be reduced to the minimum capacity, and as a result, the capacity of the cold energy utilization side equipment can be utilized to the limit.

  According to a fifth aspect of the present invention, in the absorption refrigeration apparatus according to the first, second or third aspect of the present invention, the flow-in control valve provided on the inlet side or the outlet side of the air-cooled supercooler flows into the absorber. The refrigeration capacity is controlled by changing the flow rate of the supercooled solution, or the refrigeration capacity is controlled by changing the flow rate of the supercooled solution by the flow rate adjusting valve and simultaneously changing the flow rate of the fan. It is characterized by.

  According to such a configuration, the refrigerating capacity can be controlled very easily and quickly by adjusting the flow rate of the supercooled solution using the flow rate adjusting valve, or by starting / stopping the fan or increasing / decreasing the air volume. The capability control range can be reduced to the minimum capability, and as a result, the capability of the cold energy utilization side device can be utilized to the limit.

  According to a sixth invention of the present application, in the absorption refrigeration apparatus according to the first, second or third invention, the refrigerant vapor is generated by the diluted solution from the absorber which has absorbed the refrigerant vapor and the generator, and This is a mixture of concentrated solution whose temperature has decreased due to heat exchange in the solution heat exchanger, and the flow rate of the supercooled solution flowing into the absorber by increasing or decreasing the flow rate of the solution pump that sucks and discharges these mixed solutions. The refrigeration capacity is controlled by changing the refrigeration capacity, or the refrigeration capacity is controlled by increasing or decreasing the flow rate of the solution pump and simultaneously increasing or decreasing the flow rate of the fan.

  According to such a configuration, the refrigeration capacity can be controlled easily and quickly by increasing or decreasing the flow rate of the solution pump, or by increasing or decreasing the flow rate of the solution pump and simultaneously increasing or decreasing the flow rate of the fan. The capacity control range of the absorption refrigeration apparatus can be reduced to the minimum capacity, and as a result, the capacity of the cold-use side device can be utilized to the limit.

  In the seventh invention of the present application, a generator driven by exhaust heat of the engine, a condenser, a falling liquid film type absorber, an air-cooled supercooler for supercooling the absorbing solution entering the absorber, In an exhaust heat-driven absorption refrigeration apparatus including an evaporator that is contained in a housing integrated with the absorber and evaporates while circulating the refrigerant by a refrigerant pump, the temperature of the supercooled solution flowing into the absorber and / or Alternatively, the refrigeration capacity of the absorption refrigeration system is controlled by changing the flow rate of the supercooled solution, and the refrigerant pump is stopped when the temperature of the fluid to be cooled at the outlet of the evaporator falls below a predetermined temperature. The refrigerant pump is operated to circulate the refrigerant when the temperature exceeds a predetermined temperature.

According to this configuration,
(1) Since the refrigeration capacity of the absorption refrigeration system is controlled by changing the supercooling temperature and / or flow rate of the supercooled absorption solution flowing into the absorber, for example, as in the conventional example, The control for increasing or decreasing the refrigeration capacity does not cause a time lag like the control for increasing or decreasing the refrigerant generation amount in the generator by the input control of exhaust heat and increasing or decreasing the refrigeration capacity of the absorption refrigeration system, and the refrigeration capacity increase or decrease control is quick with good responsiveness. Can be done on the
(2) When the temperature of the fluid to be cooled at the outlet of the evaporator is controlled to a low temperature by the absorption refrigeration system and becomes lower than a predetermined temperature, the refrigerant flowing into the evaporator Although there is a possibility of freezing, at this time, the refrigerant pump can be stopped to stop the inflow of the refrigerant to the evaporator, thereby rapidly reducing the refrigeration capacity and preventing the refrigerant from being frozen. When the temperature is equal to or higher than the predetermined temperature and there is no possibility that the refrigerant freezes, the refrigerant pump can be operated to circulate the refrigerant to improve the refrigerating capacity.
As a synergistic effect, it is possible to reduce the temperature of the fluid to be cooled to the limit while preventing the refrigerant from freezing, and to improve the performance of the cold energy utilization side device to the maximum extent.

  In the eighth invention of the present application, in the absorption refrigeration apparatus according to the seventh invention, the refrigeration capacity of the absorption refrigeration apparatus is calculated by calculating a deviation between the temperature of the fluid to be cooled at the outlet of the evaporator and the target temperature, or It is defined by the deviation between the temperature difference of the fluid to be cooled at the outlet and the inlet of the evaporator and the target temperature difference.

  Here, the “target temperature” or “target temperature difference” is the temperature or temperature difference based on the operating state of the cold energy utilization side device (for example, the outside air temperature when the cold energy utilization side device is a compression refrigeration apparatus). It is the refrigerant temperature after the supercooling of the compression refrigeration system or the temperature difference between the supercooling) set according to the operating load. Therefore, the refrigerating capacity of the absorption refrigeration system is restricted to the capacity corresponding to this "deviation between the temperature of the fluid to be cooled and the target temperature" or "deviation between the temperature difference of the fluid to be cooled and the target temperature difference". Thus, for example, the excessive refrigeration capacity reliably prevents the temperature of the fluid to be cooled from lowering below the target temperature and causing the refrigerant to freeze.

  In a ninth invention of the present application, in the absorption refrigeration apparatus according to the seventh or eighth invention, the predetermined temperature is equal to or lower than a target temperature of a fluid to be cooled at an outlet of the evaporator. It is characterized by being set to.

  Here, the “target temperature” is a target temperature at the time of operation of the cold energy utilization side device, and the “temperature lower than the target temperature” is a limit temperature lower than the above target temperature. Therefore, the above-mentioned “predetermined temperature”, that is, the limit temperature that may cause the refrigerant to freeze is “set to a temperature that is equal to or lower than the target temperature”, so that the capacity of the cold-use side device is used to the limit. can do.

  According to a tenth aspect of the present invention, in the absorption refrigeration apparatus according to the seventh, eighth or ninth aspect of the present invention, the air flows into the absorber by the start / stop of a fan provided in the air-cooled supercooler or the increase / decrease of the air volume. The refrigerating capacity is controlled by changing the temperature of the supercooled solution.

  According to such a configuration, the control of the refrigerating capacity by changing the temperature of the supercooled solution can be performed very easily and quickly by making use of the characteristics of the indirect air cooling system and by the start / stop of the fan or the increase / decrease of the air volume. The capacity control range of the absorption refrigeration apparatus can be reduced to the minimum capacity, and as a result, the capacity of the cold energy utilization side equipment can be utilized to the limit.

  According to an eleventh aspect of the present invention, in the absorption refrigeration apparatus according to the seventh, eighth or ninth aspect of the present invention, the absorption refrigeration apparatus flows into the absorber by a flow rate adjusting valve provided on the inlet side or the outlet side of the air-cooled supercooler. The refrigeration capacity is controlled by changing the flow rate of the supercooled solution, or the refrigeration capacity is controlled by changing the flow rate of the supercooled solution by the flow rate adjusting valve and simultaneously changing the flow rate of the fan. It is characterized by.

  According to such a configuration, the refrigerating capacity can be controlled very easily and quickly by adjusting the flow rate of the supercooled solution using the flow rate adjusting valve, or by starting / stopping the fan or increasing / decreasing the air volume. The capability control range can be reduced to the minimum capability, and as a result, the capability of the cold energy utilization side device can be utilized to the limit.

  According to a twelfth aspect of the present invention, in the absorption refrigeration apparatus according to the seventh, eighth, or ninth aspect of the invention, the refrigerant vapor is generated by the diluted solution from the absorber that has absorbed the refrigerant vapor and the generator, and This is a mixture of concentrated solution whose temperature has decreased due to heat exchange in the solution heat exchanger, and the flow rate of the supercooled solution flowing into the absorber by increasing or decreasing the flow rate of the solution pump that sucks and discharges these mixed solutions. The refrigeration capacity is controlled by changing the refrigeration capacity, or the refrigeration capacity is controlled by increasing or decreasing the flow rate of the solution pump and simultaneously increasing or decreasing the flow rate of the fan.

  According to such a configuration, the refrigeration capacity can be easily and quickly controlled by increasing or decreasing the flow rate of the solution pump, or by increasing or decreasing the flow rate of the solution pump and simultaneously increasing or decreasing the flow rate of the fan. The capacity control range of the absorption refrigeration apparatus can be reduced to the minimum capacity, and as a result, the capacity of the cold-use side device can be utilized to the limit.

  As a result, according to the absorption refrigeration apparatus of the present invention, the temperature of the fluid to be cooled can be lowered to the limit while preventing the refrigerant from freezing, and the performance of the cold-use equipment can be improved to the maximum extent. It becomes. In particular, a compression refrigeration apparatus is employed as the cold heat utilization side device, and the refrigerant from the condenser of the compression refrigeration apparatus is supercooled by the cold heat obtained by the evaporator of the absorption refrigeration apparatus. Can improve the performance of the compression refrigeration apparatus.

  Hereinafter, the present invention will be specifically described based on preferred embodiments.

I: First Embodiment FIG. 1 shows a refrigeration system according to a first embodiment of the present invention. This refrigeration system is configured by combining an exhaust heat driven absorption refrigeration apparatus Z and a compression refrigeration apparatus X.

The absorption refrigeration apparatus Z employs water (H ₂ O) as a refrigerant, lithium bromide (LiBr) as an absorption liquid, and an exhaust heat-driven air-cooled absorption refrigeration apparatus that uses exhaust hot water as a heating source. In the heat exchanger 1a, the absorption dilute solution is heated with exhaust warm water to generate the refrigerant vapor and the absorption concentrated solution, and the refrigerant vapor flowing from the generator 1 through the pipe 51 is condensed. The refrigerant to be cooled and the fluid to be cooled (that is, the refrigerant that is discharged from the condenser 23 of the compression refrigeration apparatus X described below) inside the refrigerant liquid flowing in from the condenser 2 through the pipe line 52 are contained inside. The evaporator 3 that is sprayed on the plate surface of the flowing plate heat exchanger 3a and temporarily evaporates it, and the refrigerant generated in the evaporator 3 with respect to the absorbed concentrated solution from the generator 1 A stream that absorbs vapor to form an absorbing dilute solution The plate-type heat exchanger 5a exchanges heat between the liquid film type absorber 4, the absorbing dilute solution flowing into the generator 1 through the pipe 53 and the absorbing concentrated solution flowing out of the generator 1 through the pipe 54. The mixed solution of the solution heat exchanger 5, the absorption concentrated solution from the solution heat exchanger 5 and the absorption dilute solution in the dilute solution reservoir 16 provided in the lower part of the absorber 4 is caused to flow through the line 55. An air-cooled solution cooler 6 provided with a fan 7 that is supercooled and flows into the absorber 4, and an absorbed diluted solution from the absorber 4 flows into the generator 1 through the solution heat exchanger 5. A solution pump 9 is provided.

  Here, the evaporator 3 and the absorber 4 are housed in an integral housing 15, and the unevaporated refrigerant flowing down to the lower part of the evaporator 3 flows through the bottom wall of the housing 15 as it is. It flows into the dilute solution reservoir 16 provided at the lower part of the slag and is mixed with the absorbed dilute solution in the dilute solution reservoir 16. As a result, the solution concentration is prevented from greatly changing due to an increase or decrease in the amount of refrigerant generated in the generator 1.

  The conduit 52 connecting the condenser 2 and the evaporator 3 is provided with a refrigerant electromagnetic valve 10, and the refrigerant from the condenser 2 is transferred to the absorber by opening the refrigerant electromagnetic valve 10. 4 is supplied, and the supply of the refrigerant to the evaporator 3 side is stopped by the closing operation of the refrigerant electromagnetic valve 10.

  Further, an intermediate position between the condenser 2 and the refrigerant solenoid valve 10 in the pipe 52 and the dilute solution reservoir 16 in the absorber 4 are connected via a bypass pipe 56, and the refrigerant solenoid valve 10 is closed. During operation, the refrigerant from the condenser 2 flows directly into the dilute solution reservoir 16 via the bypass line 56.

  The compression refrigeration apparatus X is configured by connecting a compressor 21, an evaporator 22, a condenser 23, an expansion valve 24, and a four-way valve 25 that are driven by an engine 26 through a pipeline. Then, the liquid refrigerant condensed and flowing out in the condenser 23 flows into the plate heat exchanger 3a of the evaporator 3 on the absorption refrigeration apparatus Z side from the lower end side through the pipe 61, The refrigerant flows out from the upper end side to the evaporator 22 side through the pipe line 62. At that time, it is supercooled in the plate heat exchanger 3a of the evaporator 3 of the absorption refrigeration apparatus.

  In order to drive the absorption refrigeration apparatus Z using the exhaust water of the engine 26 of the compression refrigeration apparatus X as a heat source, the cooling water circulation system of the engine 26 and the heat exchanger 1a of the generator 1 are connected to each other by a pipe. 57 and 58 are connected.

  The refrigeration system configured as described above operates as follows.

  First, in the compression refrigeration apparatus X, the compressor 26 of the compression refrigeration apparatus X is driven by the engine 26, and the gas refrigerant discharged from the compressor 21 is condensed in the condenser 23 to be liquid refrigerant. In addition, the liquid refrigerant is further supercooled in the evaporator 3 on the absorption refrigeration apparatus Z side, and the supercooled refrigerant is evaporated in the evaporator 22 to cool the room. In this case, the refrigeration capacity can be improved by supercooling the liquid refrigerant from the condenser 23.

  On the other hand, in the absorption refrigeration apparatus Z, the generator 1 receives the hot water from the engine 26, and the generator 1 heats the absorption dilute solution from the absorber 4 to generate refrigerant vapor and the absorption concentrated solution. . The refrigerant vapor generated in the generator 1 is condensed in the air-cooled condenser 2 provided with a fan 8 to be a liquid refrigerant.

  Here, when the refrigerant solenoid valve 10 is in an open operation, the liquid refrigerant from the condenser 2 flows into the upper part of the evaporator 3 and is supplied from the spreader (not shown) to the plate heat exchanger. It spreads evenly over the top of 3a and evaporates while flowing down along the surface of the heat exchanger 3a to generate refrigerant vapor. At this time, the refrigerant on the compression refrigeration apparatus X side flowing in the plate heat exchanger 3a is supercooled by the heat of evaporation. On the other hand, during the closing operation of the refrigerant solenoid valve 10, the liquid refrigerant from the condenser 2 flows directly into the dilute solution reservoir 16 on the absorber 4 side, and enters the evaporator 3 side. Supply is stopped.

  On the other hand, in the absorber 4, the absorption dilute solution supercooled in the air-cooled supercooler 6 is evenly sprayed from the sprayer (not shown) to the plate 4a and flows down along the plate 4a. The refrigerant vapor from the evaporator 3 is absorbed to form an absorbing diluted solution, which is stored in the diluted solution reservoir 16.

  In the dilute solution reservoir 16, the absorbed dilute solution that has absorbed the refrigerant vapor in the absorber 4, the non-evaporated refrigerant flowing in from the evaporator 3, and the bypass conduit 56 during the closing operation of the refrigerant solenoid valve 10. A mixed solution composed of refrigerant from the condenser 2 flowing in through the reservoir is stored, and the mixed solution is supplied to the generator 1 side by the solution pump 9. At this time, in the solution heat exchanger 5, heat recovery is performed by heat exchange between the absorption diluted solution from the absorber 4 side and the absorption concentrated solution generated in the generator 1.

  In the absorption refrigeration apparatus Z, the refrigeration capacity is increased or decreased by adjusting the absorption capacity in the absorber 4. That is, by increasing the absorption capacity of the absorber 4 and increasing the absorption of refrigerant vapor into the absorption diluted solution, the evaporation capacity in the evaporator 3 (that is, the supercooling capacity for the refrigerant on the compression refrigeration apparatus X side). As a result, the refrigerating capacity of the absorption refrigeration apparatus Z as a whole is enhanced.

  By the way, as described above, the refrigeration capacity of the compression refrigeration apparatus X varies depending on the degree of supercooling of the refrigerant discharged from the condenser 23, and the refrigeration capacity increases as the degree of supercooling increases. Therefore, in terms of improving the capacity of the compression refrigeration apparatus X, the refrigerant on the compression refrigeration apparatus X side needs to be supercooled as much as possible by the cold heat of the absorption refrigeration apparatus Z. What is necessary is just to combine the absorption refrigeration apparatus Z of the capability which can achieve the supercooling temperature corresponding to the refrigerating capacity of the refrigeration apparatus X.

  However, when the outside air temperature decreases or when the compression refrigeration apparatus X becomes a partial load, the refrigerant temperature (that is, the condensation temperature) at the outlet of the condenser 23 of the compression refrigeration apparatus X decreases. In particular, when the decrease in the outside air temperature and the partial load of the compression refrigeration apparatus X overlap, the absorption refrigeration apparatus has a large decrease in the refrigerant temperature at the outlet of the condenser 23 of the compression refrigeration apparatus X. The temperature range in which the refrigerant on the compression refrigeration apparatus X side can be supercooled by the cold heat of Z is reduced, and the performance improvement rate of the compression refrigeration apparatus by subcooling the refrigerant of the compression refrigeration apparatus X is greatly reduced. become. As a result, the effect of reducing the running cost of the engine-driven compression refrigeration apparatus X is less than the initial cost of the absorption refrigeration apparatus Z during the cold utilization period (that is, the cooling operation period of the compression refrigeration apparatus). .

  In addition, the control of the refrigerating capacity of the absorption refrigeration apparatus Z under a condition where the refrigerant condensing temperature of the compression refrigeration apparatus X is low, such as when the external temperature is low or when the compression refrigeration apparatus X is partially loaded, Since a margin is required, the temperature of the cooled fluid of the evaporator 3 of the absorption refrigeration apparatus Z (that is, the supercooling temperature of the refrigerant of the compression refrigeration apparatus Z) is inevitably set to the limit value (that is, LiBr is used as the absorption liquid). Therefore, in the absorption refrigeration apparatus using water as the refrigerant, the temperature can be set higher than the limit temperature at which freezing of water as the refrigerant can be avoided. The width is reduced, and the performance improvement effect of the compression refrigeration apparatus X by supercooling the refrigerant of the compression refrigeration apparatus X with the cold heat of the absorption refrigeration apparatus Z is also a factor that diminishes.

  In view of the above, in order to improve the efficiency of the compression refrigeration apparatus X, it can be said that it is effective to reduce the supercooling degree of the refrigerant to the limit.

  On the other hand, if the supercooling degree of the refrigerant of the compression refrigeration apparatus X is reduced to the limit and the efficiency of the compression refrigeration apparatus X is improved as much as possible, the outside air temperature decreases and the engine driven compression refrigeration apparatus X In the case where the decrease in the load of the refrigerant is overlapped, the refrigerating capacity of the absorption refrigeration apparatus Z becomes excessive and the refrigerant (water) flowing into the evaporator 3 may be frozen. It is necessary to quickly reduce the capacity of the device Z.

  Therefore, in this embodiment, in consideration of these circumstances, the degree of supercooling of the refrigerant of the compression refrigeration apparatus X is reduced to the limit while avoiding freezing of the refrigerant in the evaporator 3 of the absorption refrigeration apparatus Z. Thus, the capacity of the compression refrigeration apparatus X is improved.

  In order to realize such control, in this embodiment, the refrigerant temperature at the outlet of the evaporator 3, that is, the supercooling temperature of the refrigerant of the compression refrigeration apparatus X is controlled, and the characteristics of the absorber 4 of the indirect air cooling system are controlled. The evaporator is used by changing the supercooling temperature or flow rate of the absorbing dilute solution flowing into the absorber 4 and when the refrigerant supercooling temperature of the compression refrigeration apparatus X reaches a limit value. 3 is stopped to prevent the refrigerant temperature at the outlet of the evaporator 3 from further decreasing and freezing of the refrigerant, thereby reducing the refrigerant subcooling temperature of the compression refrigeration apparatus X. The efficiency of the compression refrigeration apparatus X is increased to the limit by lowering the limit.

  Specifically, a temperature sensor 18 is provided on the outlet side of the evaporator 3 to detect the supercooling temperature of the refrigerant on the compression refrigeration apparatus X side on the outlet side, and this detected temperature is input to the controller 30. At the same time, the control signal from the controller 30 controls the opening and closing of the refrigerant solenoid valve 10 and the control of the solution pump 9 by starting and stopping and the number of rotations of the pump.

  The idea of these controls is as follows.

  That is, the refrigeration capacity of the absorption refrigeration apparatus Z (the refrigeration capacity required for the absorption refrigeration apparatus Z) is determined in the condenser 23 of the compression refrigeration apparatus X determined by the outside air temperature or the load state of the compression refrigeration apparatus X. It is defined by the deviation between the refrigerant subcooling temperature (that is, the target temperature) to be obtained in accordance with the refrigerant condensation temperature and the actual supercooling temperature detected by the temperature sensor 18.

  The refrigerating capacity required for the absorption refrigeration apparatus Z is determined by the start and stop of the fan 7 provided in the air-cooled supercooler 6 or by increasing or decreasing the air volume of the fan 7. This is realized by changing the temperature of the supercooled solution circulating through the air pump 6, or by increasing or decreasing the flow rate of the solution pump 9 to increase or decrease the flow rate of the supercooled solution circulating through the air-cooled supercooler 6. . By such control, the supercooling temperature of the refrigerant on the compression refrigeration apparatus X side can be lowered to the target temperature, and the operation efficiency of the compression refrigeration apparatus X can be increased to the limit.

  On the other hand, since the absorption refrigeration apparatus Z uses water as a refrigerant, if the evaporation temperature of the evaporator 3, that is, the supercooling temperature of the refrigerant on the compression refrigeration apparatus X side, is excessively reduced, The refrigerant may freeze. Therefore, in order to prevent such freezing of the refrigerant, a limit evaporating temperature at which the refrigerant may freeze is set as a “predetermined temperature”, and the outlet side of the evaporator 3 detected by the temperature sensor 18 is set. When the refrigerant temperature falls below the predetermined value, the refrigerant solenoid valve 10 is closed to stop the supply of the refrigerant from the condenser 2 to the evaporator 3 side, and the absorption refrigeration apparatus Z Decreases the refrigeration capacity and prevents the evaporation temperature from further decreasing. When the refrigerant temperature on the outlet side of the evaporator 3 recovers to the predetermined value or more, the refrigerant electromagnetic valve 10 is opened to supply the refrigerant from the condenser 2 to the evaporator 3 side, Increase the refrigeration capacity of the absorption refrigeration system Z.

  The refrigerant supply / stop control on the evaporator 3 side prevents the refrigerant in the evaporator 3 from being frozen.

  During the closing operation of the refrigerant solenoid valve 10, the refrigerant from the condenser 2 flows directly into the dilute solution reservoir 16 provided at the lower part of the evaporator 3 through the bypass pipe 56. This suppresses a large change in the solution concentration, stabilizes the refrigerating capacity, and at the same time prevents the solution concentration from becoming excessively high, thereby controlling the capacity of the absorber and enhancing the effect of preventing the refrigerant from freezing.

  As described above, in the refrigeration system of this embodiment, the operating efficiency of the compression refrigeration apparatus X can be increased to the limit while preventing the refrigerant from freezing on the absorption refrigeration apparatus Z side. .

  In this embodiment, the refrigeration capacity of the absorption refrigeration apparatus Z is controlled on the basis of the deviation between the refrigerant temperature at the outlet of the evaporator 3 and the target temperature. The capacity can be controlled based on, for example, the deviation between the temperature difference between the outlet and the inlet of the evaporator 3 and the target temperature difference.

II: Second Embodiment FIG. 2 shows a refrigeration system according to a second embodiment of the present invention. This refrigeration system has the same basic configuration as that of the refrigeration system according to the first embodiment, and is configured by combining an exhaust heat-driven absorption refrigeration apparatus Z and a compression refrigeration apparatus X.

  The refrigeration system according to this embodiment is different from the refrigeration system according to the first embodiment in that a flow rate adjustment valve 11 is provided on the upstream side of the air-cooled supercooler 6 or a flow rate adjustment valve 12 is provided on the downstream side. This is the point.

  By providing the flow rate adjusting valve 11 or the flow rate adjusting valve 12 in this way, the refrigerating capacity of the absorption refrigeration apparatus Z can be increased or decreased by the fan 7 provided in the air-cooled supercooler 6 or the fan 7. The absorption capacity is controlled by changing the temperature of the supercooled solution circulating in the air-cooled supercooler 6 by increasing or decreasing the amount of air, or the flow rate of the solution pump 9 is increased or decreased to circulate the air-cooled supercooler 6. Instead of or simultaneously with the control of the absorption capacity by increasing or decreasing the flow rate of the cooling solution, the flow rate of the supercooling solution circulating through the air-cooled supercooler 6 by the flow rate adjusting valve 11 or the flow rate adjusting valve 12 is adjusted. The absorption capacity can be controlled by adjusting the increase / decrease, and as a result, the refrigerating capacity of the absorption refrigeration apparatus Z can be controlled with higher accuracy and speed.

  In addition, since the structure and the effect other than the above are the same as in the case of the first embodiment, the same reference numerals are given to the respective constituent members in FIG. 2 corresponding to the respective constituent members in FIG. Thus, the corresponding explanation in the first embodiment is used, and the explanation here is omitted.

III: Third Embodiment FIG. 3 shows a refrigeration system according to a third embodiment of the present invention. This refrigeration system is configured by combining an exhaust heat driven absorption refrigeration apparatus Z and a compression refrigeration apparatus X.

The absorption refrigeration apparatus Z employs water (H ₂ O) as a refrigerant, lithium bromide (LiBr) as an absorption liquid, and an exhaust heat-driven air-cooled absorption refrigeration apparatus that uses exhaust hot water as a heating source. In the heat exchanger 1a, the absorption dilute solution is heated with exhaust warm water to generate the refrigerant vapor and the absorption concentrated solution, and the refrigerant vapor flowing from the generator 1 through the pipe 51 is condensed. The refrigerant 2 flowing into the refrigerant reservoir 17 provided in the lower part of the evaporator 3 from the condenser 2 through the conduit 52 and the evaporator 3 is cooled with the fluid to be cooled (that is, the compression refrigeration described below). The refrigerant pump 13 is circulated so as to be sprayed on the plate surface of the plate heat exchanger 3a through which the refrigerant flowing out of the condenser 23 of the apparatus X flows, and the refrigerant liquid circulated by the refrigerant pump 13 is exchanged with the plate heat exchanger. Of the container 3a A recirculating evaporator 3 that is sprayed on the surface of the steam and evaporates it, and an absorbing concentrated solution from the generator 1 absorbs the refrigerant vapor generated in the evaporator 3 to generate an absorbing diluted solution. The plate-type heat exchanger 5a heats the falling film absorber 4 to be discharged, the absorption dilute solution flowing into the generator 1 through the pipe 53 and the absorption concentrated solution flowing out of the generator 1 through the pipe 54. The solution heat exchanger 5 to be exchanged, and the mixed solution of the absorption concentrated solution from the solution heat exchanger 5 and the absorption dilute solution in the dilute solution reservoir 16 provided in the lower part of the absorber 4 are caused to flow through the line 55. An air-cooled solution cooler 6 provided with a fan 7 that supercools this and flows into the absorber 4, and the absorbed dilute solution from the absorber 4 through the solution heat exchanger 6 and the generator 1. It is provided with a solution pump 9 that flows into the apparatus.

  Here, the evaporator 3 and the absorber 4 are housed in an integral housing 15, and the unevaporated refrigerant flowing down to the lower part of the evaporator 3 is circulated to the upper part of the evaporator 3 by the refrigerant pump 13. However, the non-evaporated refrigerant that has overflowed from the refrigerant pool 17 without flowing through it flows through the bottom wall of the casing 15 and flows into the dilute solution reservoir 16 provided at the lower part of the absorber 4. 16 is mixed with the absorbing dilute solution. As a result, the solution concentration is prevented from greatly changing due to an increase or decrease in the amount of refrigerant generated in the generator 1.

  The compression refrigeration apparatus X is configured by connecting a compressor 21, an evaporator 22, a condenser 23, an expansion valve 24, and a four-way valve 25 that are driven by an engine 26 through a pipeline. Then, the liquid refrigerant condensed and flowing out in the condenser 23 flows into the plate heat exchanger 3a of the evaporator 3 on the absorption refrigeration apparatus Z side from the lower end side through the pipe 61, It flows out from the upper end side to the evaporator 22 side through the pipe line 62, but at that time, it is supercooled in the plate heat exchanger 3 a of the evaporator 3.

  In order to drive the absorption refrigeration apparatus Z using the exhaust water of the engine 26 of the compression refrigeration apparatus X as a heat source, the cooling water circulation system of the engine 26 and the heat exchanger 1a of the generator 1 are connected to each other by a pipe. 57 and 58 are connected.

  The refrigeration system configured as described above operates as follows.

  First, in the compression refrigeration apparatus X, the compressor 26 of the compression refrigeration apparatus X is driven by the engine 26, and the gas refrigerant discharged from the compressor 21 is condensed in the condenser 23 to be liquid refrigerant. In addition, the liquid refrigerant is further supercooled in the evaporator 3 on the absorption refrigeration apparatus Z side, and the supercooled refrigerant is evaporated in the evaporator 22 to cool the room. In this case, the refrigeration capacity can be improved by supercooling the liquid refrigerant from the condenser 23.

  On the other hand, in the absorption refrigeration apparatus Z, the generator 1 receives the hot water from the engine 26, and the generator 1 heats the absorption dilute solution from the absorber 4 to generate refrigerant vapor and the absorption concentrated solution. . The refrigerant vapor generated in the generator 1 is condensed in the air-cooled condenser 2 provided with a fan 8 to be a liquid refrigerant.

  The liquid refrigerant from the condenser 2 flows into the refrigerant reservoir 17, and then flows into the upper part of the evaporator 3 by the refrigerant pump 13, and from the spreader (not shown) to the upper part of the plate heat exchanger 3a. And is vaporized while flowing down along the surface of the heat exchanger 3a to generate refrigerant vapor. At this time, the refrigerant on the compression refrigeration apparatus X side flowing in the plate heat exchanger 3a is supercooled by the heat of evaporation.

  On the other hand, in the absorber 4, the absorption dilute solution supercooled in the air-cooled supercooler 6 is evenly sprayed from the sprayer (not shown) to the plate 4a and flows down along the plate 4a. The refrigerant vapor from the evaporator 3 is absorbed to form an absorbing diluted solution, which is stored in the diluted solution reservoir 16.

  The dilute solution reservoir 16 stores a mixed solution composed of an absorbed dilute solution that has absorbed refrigerant vapor in the absorber 4 and an unevaporated refrigerant that flows in from the evaporator 3, and the mixed solution is stored in the solution pump. 9 to the generator 1 side. At this time, in the solution heat exchanger 5, heat recovery is performed by heat exchange between the absorption diluted solution from the absorber 4 side and the absorption concentrated solution generated in the generator 1.

  In the absorption refrigeration apparatus Z, the refrigeration capacity is increased or decreased by adjusting the absorption capacity in the absorber 4. That is, by increasing the supercooling temperature of the solution flowing into the absorber 4 and increasing the absorption capacity to enhance the absorption of the refrigerant vapor into the absorption solution, the evaporation capacity (that is, the compression refrigeration apparatus) in the evaporator 3 is increased. The supercooling capacity of the refrigerant on the X side) is increased, and as a result, the refrigerating capacity of the absorption refrigeration apparatus Z as a whole is increased.

  By the way, as described above, the refrigeration capacity of the compression refrigeration apparatus X varies depending on the degree of supercooling of the refrigerant discharged from the condenser 23, and the refrigeration capacity increases as the degree of supercooling increases. Therefore, in terms of improving the capacity of the compression refrigeration apparatus X, the refrigerant on the compression refrigeration apparatus X side needs to be supercooled as much as possible by the cold heat of the absorption refrigeration apparatus Z. What is necessary is just to combine the absorption refrigeration apparatus Z of the capability which can achieve the supercooling temperature corresponding to the refrigerating capacity of the refrigeration apparatus X.

  However, when the outside air temperature decreases or when the compression refrigeration apparatus X becomes a partial load, the refrigerant temperature (that is, the condensation temperature) at the outlet of the condenser 23 of the compression refrigeration apparatus X decreases. In particular, when the decrease in the outside air temperature and the partial load of the compression refrigeration apparatus X overlap, the absorption refrigeration apparatus has a large decrease in the refrigerant temperature at the outlet of the condenser 23 of the compression refrigeration apparatus X. The temperature range in which the refrigerant on the compression refrigeration apparatus X side can be supercooled by the cold heat of Z is reduced, and the performance improvement rate of the compression refrigeration apparatus by subcooling the refrigerant of the compression refrigeration apparatus X is greatly reduced. become. As a result, the effect of reducing the running cost of the engine-driven compression refrigeration apparatus X is less than the initial cost of the absorption refrigeration apparatus Z during the cold utilization period (that is, the cooling operation period of the compression refrigeration apparatus). .

  In addition, the control of the refrigerating capacity of the absorption refrigeration apparatus Z under a condition where the refrigerant condensing temperature of the compression refrigeration apparatus X is low, such as when the external temperature is low or when the compression refrigeration apparatus X is partially loaded, Since a margin is required, the temperature of the cooled fluid of the evaporator 3 of the absorption refrigeration apparatus Z (that is, the supercooling temperature of the refrigerant of the compression refrigeration apparatus Z) is inevitably set to the limit value (that is, LiBr is used as the absorption liquid). Therefore, in the absorption refrigeration apparatus using water as the refrigerant, the temperature can be set higher than the limit temperature at which freezing of water as the refrigerant can be avoided. The width is reduced, and the performance improvement effect of the compression refrigeration apparatus X by supercooling the refrigerant of the compression refrigeration apparatus X with the cold heat of the absorption refrigeration apparatus Z is also a factor that diminishes.

  In view of the above, in order to improve the efficiency of the compression refrigeration apparatus X, it can be said that it is effective to reduce the supercooling degree of the refrigerant to the limit.

  On the other hand, if the supercooling degree of the refrigerant of the compression refrigeration apparatus X is reduced to the limit and the efficiency of the compression refrigeration apparatus X is improved as much as possible, the outside air temperature decreases and the engine driven compression refrigeration apparatus X In the case where the decrease in the load of the refrigerant is overlapped, the refrigerating capacity of the absorption refrigeration apparatus Z becomes excessive and the refrigerant (water) flowing into the evaporator 3 may be frozen. It is necessary to quickly reduce the capacity of the device Z.

  Therefore, in this embodiment, in consideration of these circumstances, the degree of supercooling of the refrigerant of the compression refrigeration apparatus X is reduced to the limit while avoiding freezing of the refrigerant in the evaporator 3 of the absorption refrigeration apparatus Z. Thus, the capacity of the compression refrigeration apparatus X is improved.

  In order to realize such control, in this embodiment, the refrigerant temperature at the outlet of the evaporator 3, that is, the supercooling temperature of the refrigerant of the compression refrigeration apparatus X is controlled, and the characteristics of the absorber 4 of the indirect air cooling system are controlled. This is performed by changing the supercooling temperature of the absorbing dilute solution flowing into the absorber 4 and when the supercooling temperature of the refrigerant of the compression refrigeration apparatus X reaches a limit value, By changing the supercooling temperature and adjusting the amount of refrigerant supplied to the evaporator 3, the refrigerant temperature at the outlet of the evaporator 3 is further reduced and freezing of the refrigerant occurs. Thus, the supercooling temperature of the refrigerant of the compression refrigeration apparatus X is lowered to the limit, and the efficiency of the compression refrigeration apparatus X is increased to the limit.

  Specifically, a temperature sensor 18 is provided on the outlet side of the evaporator 3 to detect the supercooling temperature of the refrigerant on the compression refrigeration apparatus X side on the outlet side, and this detected temperature is input to the controller 30. At the same time, the operation of the fan 7, the refrigerant pump 13, and the solution pump 9 is controlled by a control signal from the controller 30.

  The idea of these controls is as follows.

  That is, the refrigeration capacity of the absorption refrigeration apparatus Z (the refrigeration capacity required for the absorption refrigeration apparatus Z) is determined in the condenser 23 of the compression refrigeration apparatus X determined by the outside air temperature or the load state of the compression refrigeration apparatus X. It is defined by the deviation between the refrigerant subcooling temperature (that is, the target temperature) to be obtained in accordance with the refrigerant condensation temperature and the actual supercooling temperature detected by the temperature sensor 18.

  The refrigerating capacity required for the absorption refrigeration apparatus Z is determined by the start and stop of the fan 7 provided in the air-cooled supercooler 6 or by increasing or decreasing the air volume of the fan 7. This is realized by increasing or decreasing the flow rate of the supercooled solution circulating through the air-cooled supercooler 6 by changing the temperature of the supercooled solution circulating through the air pump 6, or by increasing or decreasing the flow rate of the solution pump. By such control, the supercooling temperature of the refrigerant on the compression refrigeration apparatus X side can be lowered to the target temperature, and the operation efficiency of the compression refrigeration apparatus X can be increased to the limit.

  On the other hand, since the absorption refrigeration apparatus Z uses water as a refrigerant, if the evaporation temperature of the evaporator 3, that is, the supercooling temperature of the refrigerant on the compression refrigeration apparatus X side, is excessively reduced, The refrigerant may freeze. Therefore, in order to prevent such freezing of the refrigerant, a limit evaporating temperature at which the refrigerant may freeze is set as a “predetermined temperature”, and the outlet side of the evaporator 3 detected by the temperature sensor 18 is set. When the refrigerant temperature of the air-cooled supercooler 6 falls below the predetermined value, the fan 7 of the air-cooled supercooler 6 is stopped or the air volume is reduced to lower the temperature of the supercooled solution to suppress the absorption capacity, By stopping the refrigerant pump 13 and stopping the supply of the refrigerant to the evaporator 3 side, the refrigeration capacity of the absorption refrigeration apparatus Z is reduced, and the evaporation temperature is prevented from further decreasing. When the refrigerant temperature on the outlet side of the evaporator 3 recovers to the predetermined value or more, the operation of the refrigerant pump 13 is resumed, the refrigerant is supplied to the evaporator 3 side, and the fan 7 is operated. Alternatively, the refrigeration capacity of the absorption refrigeration apparatus Z is increased by increasing the air volume.

  The refrigerant supply / stop control on the evaporator 3 side and the temperature control of the supercooled solution on the absorber 4 side prevent the refrigerant from freezing in the evaporator 3 in advance.

  As described above, in the refrigeration system of this embodiment, the operating efficiency of the compression refrigeration apparatus X can be increased to the limit while preventing the refrigerant from freezing on the absorption refrigeration apparatus Z side. .

  In this embodiment, the refrigeration capacity of the absorption refrigeration apparatus Z is controlled on the basis of the deviation between the refrigerant temperature at the outlet of the evaporator 3 and the target temperature. The capacity can be controlled based on, for example, the deviation between the temperature difference between the outlet and the inlet of the evaporator 3 and the target temperature difference.

IV: Fourth Embodiment FIG. 4 shows a refrigeration system according to a fourth embodiment of the present invention. This refrigeration system has the same basic configuration as the refrigeration system according to the third embodiment, and is configured by combining an exhaust heat driven absorption refrigeration apparatus Z and a compression refrigeration apparatus X.

  The refrigeration system according to this embodiment differs from the refrigeration system according to the third embodiment in that a flow rate adjustment valve 11 is provided on the upstream side of the air-cooling supercooler 6 or a flow rate adjustment valve 12 is provided on the downstream side. This is the point.

  By providing the flow rate adjusting valve 11 or the flow rate adjusting valve 12 in this way, the refrigerating capacity of the absorption refrigeration apparatus Z can be increased or decreased by the fan 7 provided in the air-cooled supercooler 6 or the fan 7. Instead of or simultaneously with the control of the absorption capacity by changing the temperature of the supercooled solution circulating in the air-cooled supercooler 6 by increasing or decreasing the air volume, the air-cooling is performed by the flow rate regulating valve 11 or the flow rate regulating valve 12. The absorption capacity can be controlled by increasing / decreasing the flow rate of the supercooled solution circulating through the supercooler 6, and as a result, the refrigerating capacity of the absorption refrigeration apparatus Z can be controlled with higher accuracy and speed. Is.

  In addition, since the structure and the effect other than the above are the same as in the case of the third embodiment, the same reference numerals are given to the respective constituent members in FIG. 4 corresponding to the respective constituent members in FIG. Thus, the corresponding explanation in the third embodiment is used, and the explanation here is omitted.

1 is a system diagram of an absorption refrigeration apparatus according to a first embodiment of the present invention. It is a system diagram of an absorption refrigeration apparatus according to a second embodiment of the present invention. It is a system diagram of the absorption refrigeration apparatus which concerns on 3rd Embodiment of this invention. It is a system diagram of an absorption refrigeration apparatus according to a fourth embodiment of the present invention.

Explanation of symbols

1 ·· Generator 2 ·· Condenser 3 ·· Evaporator 4 ··· Absorber 5 ·· Solution heat exchanger 6 ·· Air-cooled supercooler 7 ·· Fan 8 ·· Fan 9 ·· Solution pump 10 ··· Refrigerant solenoid valve 11 .. Flow rate adjusting valve 12 .. Flow rate adjusting valve 13 .. Refrigerant pump 15 .. Housing 16 .. Diluted solution reservoir 17 .. Refrigerant reservoir 18 .. Temperature sensor 21 .. Compressor 22 .. Evaporator 23 .. Condenser 24 .. Expansion valve 25 .. Four-way valve 26 .. Engine 30 .. Controller

Claims (12)

A generator driven by engine exhaust heat, a condenser, a falling film absorber, an air-cooled supercooler that supercools the absorbing solution entering the absorber, and a housing integrated with the absorber Is an exhaust heat driven absorption refrigeration apparatus equipped with an evaporator that temporarily evaporates the refrigerant,
The refrigeration capacity of the absorption refrigeration system shall be controlled by changing the temperature of the supercooled solution flowing into the absorber and / or the flow rate of the supercooled solution,
When the temperature of the fluid to be cooled at the outlet of the evaporator becomes equal to or lower than a predetermined temperature, the refrigerant solenoid valve provided in the pipe from the condenser to the evaporator is closed to stop the flow of the refrigerant into the evaporator. When the temperature exceeds a predetermined temperature, the refrigerant solenoid valve is opened to allow the refrigerant from the condenser to flow into the evaporator, and the refrigerant is removed from the condenser while the refrigerant solenoid valve is closed. An absorption refrigeration apparatus characterized in that it directly flows into a dilute solution reservoir below the absorber.   The refrigeration capacity of the absorption refrigeration system is the deviation between the temperature of the cooled fluid at the outlet of the evaporator and the target temperature, or the difference between the temperature difference of the cooled fluid at the outlet and the inlet of the evaporator and the target temperature difference. The absorption refrigeration apparatus according to claim 1, wherein the absorption refrigeration apparatus is provided.   The absorption refrigeration apparatus according to claim 1 or 2, wherein the predetermined temperature is equal to or lower than a target temperature of a fluid to be cooled at an outlet of the evaporator.   The refrigeration capacity is controlled by changing the temperature of the supercooled solution flowing into the absorber by the start / stop of a fan provided in the air-cooled supercooler or the increase / decrease of the air volume. The absorption refrigeration apparatus according to 1, 2, or 3. The refrigeration capacity is controlled by changing the flow rate of the supercooled solution flowing into the absorber by the flow rate adjusting valve provided on the inlet side or the outlet side of the air-cooled supercooler,
The absorption refrigeration apparatus according to claim 1, 2 or 3, wherein the refrigerating capacity is controlled by changing the flow rate of the supercooled solution by the flow rate adjusting valve and simultaneously increasing or decreasing the amount of air flow of the fan. . Mixing the dilute solution from the absorber that has absorbed the refrigerant vapor with the concentrated solution that has generated the refrigerant vapor in the generator and whose temperature has been reduced by heat exchange in the solution heat exchanger,
Control the refrigeration capacity by changing the flow rate of the supercooled solution flowing into the absorber by increasing or decreasing the flow rate of the solution pump that sucks and discharges these mixed solutions,
4. The absorption refrigeration apparatus according to claim 1, wherein the refrigeration capacity is controlled by increasing or decreasing the flow rate of the solution pump and simultaneously increasing or decreasing the fan flow rate. A generator driven by engine exhaust heat, a condenser, a falling film absorber, an air-cooled supercooler that supercools the absorbing solution entering the absorber, and a housing integrated with the absorber An exhaust-heat-driven absorption refrigeration apparatus equipped with an evaporator that evaporates while circulating the refrigerant by a refrigerant pump,
The refrigeration capacity of the absorption refrigeration system shall be controlled by changing the temperature of the supercooled solution flowing into the absorber and / or the flow rate of the supercooled solution,
The refrigerant pump is stopped when the temperature of the fluid to be cooled at the outlet of the evaporator becomes a predetermined temperature or lower, and the refrigerant pump is operated to circulate the refrigerant when the temperature becomes the predetermined temperature or higher. An absorption refrigeration apparatus characterized by the above.   The refrigerating capacity of the absorption refrigeration apparatus is a deviation between the temperature of the cooled fluid at the outlet of the evaporator and the target temperature, or a deviation between the temperature difference of the cooled fluid at the outlet and the inlet of the evaporator and the target temperature difference. The absorption refrigeration apparatus according to claim 7, characterized in that:   The absorption refrigeration apparatus according to claim 7 or 8, wherein the predetermined temperature is equal to or lower than a target temperature of a fluid to be cooled at an outlet of the evaporator.   8. The refrigerating capacity is controlled by changing the temperature of the supercooled solution flowing into the absorber by the start / stop of a fan provided in the air-cooled supercooler or the increase / decrease of the air volume. The absorption refrigeration apparatus according to claim 8 or 9. The refrigeration capacity is controlled by changing the flow rate of the supercooled solution flowing into the absorber by the flow rate adjusting valve provided on the inlet side or the outlet side of the air-cooled supercooler,
The absorption refrigeration apparatus according to claim 7, 8 or 9, wherein the refrigerating capacity is controlled by changing the flow rate of the supercooled solution by the flow rate adjusting valve and simultaneously increasing or decreasing the fan flow rate. . Mixing the dilute solution from the absorber that has absorbed the refrigerant vapor with the concentrated solution that has generated the refrigerant vapor in the generator and whose temperature has been reduced by heat exchange in the solution heat exchanger,
Control the refrigeration capacity by changing the flow rate of the supercooled solution flowing into the absorber by increasing or decreasing the flow rate of the solution pump that sucks and discharges these mixed solutions,
The absorption refrigeration apparatus according to claim 7, 8 or 9, wherein the refrigeration capacity is controlled by increasing or decreasing the flow rate of the solution pump and simultaneously increasing or decreasing the fan flow rate.

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