JP2010078298A - Absorption refrigerator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an absorption refrigerator capable of improving an average of COP during low load operation of less than 20 percent. <P>SOLUTION: The absorption refrigerator includes at least a high temperature regenerator 1, a low temperature regenerator 3, a condenser 4, an evaporator 5 passing cold and hot water to be supplied to a load via a cold and hot water pipe 17, an absorber 6, a refrigerant pump 14, and absorbent pumps 20, 22. During a low load of cooling operation, a temperature of cold water switching OFF combustion of a burner 2 of the high temperature regenerator 1 is set higher than a set temperature for just a predetermined temperature. Alternatively, during a low load of heating operation, a temperature of hot water switching OFF the combustion of the burner 2 of the high temperature regenerator 1 is set lower than the set temperature for just a predetermined temperature. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an absorption chiller designed to improve COP (coefficient of performance) particularly during low-load operation.

  In general, absorption chillers used for building air conditioners and large store refrigeration and refrigeration systems are widely known. A typical example is a double-effect absorption chiller (hereinafter simply called absorption refrigeration). May be referred to as a machine). This absorption refrigerator usually includes a high temperature regenerator, a low temperature regenerator, a condenser, an evaporator, and an absorber, and includes a refrigerant pump, an absorption liquid pump, a low temperature heat exchanger, a high temperature heat exchanger, and the like. A circulation path is configured by connecting the pipes. For example, an aqueous lithium bromide solution is used as the absorbing solution, and water is used as the refrigerant.

The conventional absorption refrigerator as described above is disclosed in, for example, Patent Document 1.
JP 2006-170569 A

  In air conditioning in hospitals, nursing homes, hotels, etc., the fact that the operation time of the absorption chiller in a low load state with a load factor of 20% or less is much longer than the time to operate at other load factors. Reported to the Society for Air Conditioning Hygiene. In an absorption chiller, a burner is usually burned in a high-temperature regenerator to heat the rare absorbent, and the refrigerant vapor separated from the rare absorbent is supplied to the low-temperature regenerator through the refrigerant pipe and becomes a medium concentration. The absorbed liquid (hereinafter referred to as intermediate absorbent) is allowed to pass through the low temperature regenerator through the absorbent liquid tube.

  It is designed so that the combustion rate of the burner in the high-temperature regenerator is adjusted by a control valve or the like in accordance with the fluctuation of the air conditioning load, and proportional control can be performed within a load factor range of 20 to 100%. However, within a range where the load factor is less than 20%, proportional control of the burner combustion amount by a control valve or the like becomes mechanically difficult. For this reason, when the load factor is less than 20%, the burner combustion switch is turned ON / OFF (hereinafter referred to as combustion ON-OFF control) to adjust the burner combustion amount and cope with low load operation. I am letting.

  In the above combustion ON-OFF control method, when the temperature of the chilled water supplied to the load falls below the rated temperature at the time of low load in the cooling operation, the combustion of the burner is turned OFF so that the cooling does not become excessive. I have control. However, even if combustion of the burner is stopped when the temperature falls below the rated temperature of the cold water, the temperature of the cold water tends to decrease too much. For this reason, in the process of switching the burner combustion to ON and returning the temperature of the cold water to the rated temperature after a lapse of a certain time from the time of combustion OFF, there is a problem that the average COP is lowered because the burner combustion amount increases. .

  Further, at the time of low load in the heating operation, when the temperature of the hot water becomes equal to or higher than the rated temperature, combustion of the burner is turned off, and thereby control is performed so as not to overheat. However, even if combustion of the burner is stopped when the temperature exceeds the rated temperature of the hot water, the temperature of the hot water tends to increase too much. For this reason, it is necessary to control appropriately so that the temperature of warm water does not rise too much. Control that results in excessive heating results in a decrease in the average COP due to an increase in the amount of burner burn.

  The present invention has been made to solve the problems of the conventional absorption refrigerator as described above, and an object of the invention is to provide an absorption refrigerator that can improve the average COP especially during low-load operation. To do.

  As means for achieving the above object, claim 1 of the present invention includes a high temperature regenerator, a low temperature regenerator, a condenser, and an evaporator through which cold / hot water supplied to a load passes through a cold / hot water pipe. An absorption refrigerator having at least an absorber, a refrigerant pump, and an absorption liquid pump, and when the cooling operation is under a low load, the temperature of the cold water for switching off the combustion of the high-temperature regenerator is set to a predetermined temperature from the set temperature. It is characterized by being set high.

  According to a second aspect of the present invention, in the absorption refrigeration machine according to the first aspect, the temperature of the cold water for switching off the refrigerant pump is set lower by a predetermined temperature than the set temperature.

  A third aspect of the present invention is the absorption refrigerator according to the first aspect, wherein a difference between an evaporator inlet temperature and an outlet temperature of the cold water passing through the evaporator through the cold / hot water pipe is equal to or lower than a predetermined temperature, and When the state below the predetermined temperature continues for a predetermined time, the combustion of the high-temperature regenerator during the cooling operation low load is switched to OFF.

  According to a fourth aspect of the present invention, in the absorption refrigerator according to the first aspect, the combustion of the high-temperature regenerator is switched to OFF by combining the second and third aspects.

  According to a fifth aspect of the present invention, in the absorption chiller of the first aspect, when the cooling capacity is equal to or less than a predetermined ratio of the rating, and the state of the predetermined ratio or less continues for a predetermined time, the cooling operation is performed at a low load. The combustion of the high-temperature regenerator is switched off.

  According to a sixth aspect of the present invention, in the absorption refrigerator according to the first aspect, both the number of times of combustion OFF of the high-temperature regenerator per predetermined time and the number of times of OFF of the refrigerant pump connected to the evaporator are both. The combustion of the high-temperature regenerator is switched to OFF when the cooling operation is under a low load when the predetermined number of times is reached.

  Claim 7 of the present invention is the absorption refrigerator of claim 1, wherein two or more of claims 3, 5 and 6 are combined to turn off combustion of the high-temperature regenerator at the time of the cooling operation low load, Alternatively, the operation of the refrigerant pump is switched off.

  Claim 8 of the present invention is a high temperature regenerator, a low temperature regenerator, a condenser, an evaporator through which cold / hot water supplied to a load passes through a cold / hot water pipe, an absorber, a refrigerant pump and an absorption liquid pump. The temperature of the hot water for switching off the combustion of the high-temperature regenerator is set lower than the set temperature by a predetermined temperature when the heating operation is under a low load.

  A ninth aspect of the present invention is the absorption refrigerator according to the eighth aspect, wherein a difference between an evaporator inlet temperature and an outlet temperature of hot water passing through the evaporator through the cold / hot water pipe is not less than a predetermined temperature, and The combustion of the high-temperature regenerator is switched off when the state of the predetermined temperature or higher continues for a predetermined time.

  According to a tenth aspect of the present invention, in the absorption refrigerator according to the eighth aspect, the combustion of the high-temperature regenerator is performed when the heating capacity is equal to or higher than a predetermined ratio of the rating and the predetermined ratio or higher continues for a predetermined time. Is switched to OFF.

  According to an eleventh aspect of the present invention, in the absorption chiller according to the eighth aspect, the number of times of combustion OFF of the high temperature regenerator per unit time and the number of times of OFF of the refrigerant pump connected to the evaporator are both greater than or equal to the predetermined number. In this case, the combustion of the high-temperature regenerator is switched off.

  According to a twelfth aspect of the present invention, in the absorption refrigerator of the eighth aspect, the combustion of the high-temperature regenerator is switched to OFF by combining two or more of the ninth, tenth, and eleventh aspects. .

  A thirteenth aspect of the present invention is the absorption refrigerator according to the first or eighth aspect, wherein the high-temperature regenerator uses steam or hot water as a heat source in place of combustion of the burner.

  According to the first aspect of the present invention, when cooling with an absorption refrigerator, the temperature of the chilled water for switching off the combustion of the high-temperature regenerator during low load operation is set higher than the set temperature by a predetermined temperature. Temperature drop can be suppressed. As a result, the temperature of the chilled water can be prevented from excessively decreasing, and the burner combustion amount in the process of switching the burner combustion to ON and returning the chilled water temperature to the rated temperature after a certain period of time has elapsed since the combustion was turned off. As a result, the average COP can be improved. In particular, when applied at low load operation, such as hospitals and nursing homes where cooling is performed for a long time with a load factor of 20% or less, the effect of significantly improving the average COP is achieved.

  According to the second aspect of the present invention, combustion of the burner in the high-temperature regenerator 1 can be reduced by extending the operation of the refrigerant pump to lower the cold water take-out temperature as much as possible. Thereby, it can contribute to the improvement of average COP at the time of low load operation.

  According to the third aspect of the present invention, the difference between the evaporator inlet temperature and the outlet temperature of the cold water passing through the evaporator via the cold / hot water pipe is equal to or lower than the predetermined temperature, and the state equal to or lower than the predetermined temperature is the predetermined time. When continuing, by switching off the combustion of the high-temperature regenerator at the time of the cooling operation low load, it is possible to appropriately determine when the combustion is switched off.

  According to the fourth aspect of the invention, by combining the second and third aspects, the combustion of the high-temperature regenerator can be appropriately switched off and the average COP can be improved efficiently.

  According to the fifth aspect of the present invention, when the cooling capacity is equal to or less than a predetermined ratio of the rating and the state equal to or less than the predetermined ratio continues for a predetermined time, the combustion of the high temperature regenerator at the time of the cooling operation low load is turned off. By switching, it is possible to appropriately determine when the combustion is switched off.

  According to the sixth aspect of the present invention, when both the number of times of combustion OFF of the high temperature regenerator per predetermined time and the number of times of OFF of the refrigerant pump connected to the evaporator are equal to or greater than the predetermined number, By switching the combustion of the high-temperature regenerator at the time of cooling operation low load to OFF, it is possible to appropriately determine when the combustion is switched off.

  According to the seventh aspect of the invention, by combining two or more of the third, fifth and sixth aspects, the combustion of the high-temperature regenerator at the time of the cooling operation low load is turned off, or the operation of the refrigerant pump is turned off. It is possible to reduce the combustion of the burner in the high-temperature regenerator by switching the combustion OFF more appropriately, or by reducing the cold water extraction temperature as much as possible by extending the operation of the refrigerant pump. it can.

  According to the eighth aspect of the present invention, when heating with an absorption refrigerator, the temperature of the cold water for switching off the combustion of the high-temperature regenerator during low load operation is set lower than the set temperature by a predetermined temperature. Temperature rise can be suppressed. Thereby, it can prevent that the temperature of warm water rises excessively, and since the combustion amount of a burner is decreased compared with the past, average COP can be improved. In particular, when applied at low load operation in a hospital or a nursing home where heating is performed for a long time with a load factor of 20% or less, the average COP is significantly improved.

  According to the ninth aspect of the present invention, the difference between the evaporator inlet temperature and the outlet temperature of the hot water passing through the evaporator through the cold / hot water pipe is equal to or higher than a predetermined temperature, and the state equal to or higher than the predetermined temperature is predetermined. When the time is continued, by switching the combustion of the high-temperature regenerator to OFF, it is possible to appropriately determine the switching time of the combustion OFF.

  According to the invention of claim 10, when the heating capacity is equal to or higher than a predetermined ratio of the rating and the state exceeding the predetermined ratio continues for a predetermined time, the combustion of the high-temperature regenerator is switched to OFF, It is possible to appropriately determine when the combustion is switched off.

  According to the eleventh aspect of the invention, the high temperature regeneration is performed when the number of times of combustion OFF of the high temperature regenerator per unit time and the number of times of turn off of the refrigerant pump connected to the evaporator are both equal to or greater than the predetermined number. By switching the combustion of the chamber to OFF, it is possible to appropriately determine when the combustion is switched off.

  According to the twelfth aspect of the present invention, by combining two or more of the ninth, tenth and eleventh aspects and switching the combustion of the high-temperature regenerator to OFF, the switching time of the combustion OFF can be made more appropriate. Can be determined.

  According to the thirteenth aspect of the present invention, the high-temperature regenerator can be similarly applied even to an absorption refrigerating machine in which steam or hot water is used as a heat source instead of combustion of a burner.

  Next, embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a configuration diagram showing a first embodiment of an absorption refrigerator according to the present invention.

  In FIG. 1, reference numeral 1 denotes a high-temperature regenerator, which includes a burner 2 as a heating source, and heats the rare absorbent returned from the absorber 6 to evaporate and separate the refrigerant vapor. The high-temperature refrigerant vapor evaporated and separated by the high-temperature regenerator 1 passes through the inside of the low-temperature regenerator 3 through the refrigerant pipe 7 and is supplied into the bottom of the condenser 4. Further, the intermediate absorbing liquid that has become a medium concentration by evaporating and separating the refrigerant vapor in the high temperature regenerator 1 is supplied to the low temperature regenerator 3 through the intermediate absorbing liquid pipe 8. A high temperature heat exchanger 9 is connected in the middle of the intermediate absorption liquid pipe 8, and the rare absorption liquid returned from the absorber 6 to the high temperature regenerator 1 through the rare absorption liquid pipe 10 and the intermediate absorption liquid are heated. Exchange.

  In the low-temperature regenerator 3, the intermediate absorption liquid supplied from the high-temperature regenerator 1 is heated by the high-temperature refrigerant vapor passing through the low-temperature regenerator 3 through the refrigerant pipe 7, and the refrigerant vapor is again evaporated and separated. . The evaporated and separated refrigerant vapor flows into the condenser 4, is cooled by the cooling water passing through the cooling water pipe 11 through the condenser 4, is condensed, and becomes a refrigerant liquid and accumulates at the bottom of the condenser 4. . Further, the refrigerant vapor in the refrigerant pipe 7 radiated by the low-temperature regenerator 3 is further radiated and condensed by the refrigerant drain heat recovery device 12, and is supplied to the bottom of the condenser 4 as a refrigerant liquid. It merges with the refrigerant liquid condensed inside. The cooling water pipe 11 passes through the condenser 4 after passing through the absorber 6, and the cooling water has an endothermic action in the absorber 6 and the condenser 4.

  The refrigerant liquid collected at the bottom of the condenser 4 is supplied to the evaporator 5 through the refrigerant liquid pipe 13, and the refrigerant liquid collected at the bottom of the evaporator 5 is passed through the refrigerant liquid pipe 15 by the refrigerant pump 14. It is sprayed to the cold / hot water pipe 17 from the refrigerant | coolant sprayer 16 arrange | positioned in the upper part in the evaporator 5. FIG. The cold / hot water pipe 17 is connected to a load (not shown) such as an indoor unit so as to pass through the evaporator 5. When the cold water returned from the load passes through the evaporator 5 during the cooling operation. Further, the refrigerant is cooled by evaporation of the refrigerant liquid sprayed from the refrigerant sprayer 16 and can be supplied to the load.

  The refrigerant vapor evaporated in the evaporator 5 flows into the absorber 6 and is absorbed by the concentrated absorbent sprayed from the absorbent sprayer 18 disposed in the upper portion and accumulates at the bottom of the absorber 6. The concentrated absorbent sprayed from the absorbent sprayer 18 is obtained by evaporating and separating the refrigerant vapor from the intermediate absorbent in the low-temperature regenerator 3 to form a concentrated absorbent. It is supplied to the absorbing liquid spreader 18 of the absorber 6 through the pipe 20. A low temperature heat exchanger 21 is connected in the middle of the concentrated absorbent pipe 20.

  The rare absorbent that has absorbed the refrigerant vapor and accumulated at the bottom of the absorber 6 is supplied to the high-temperature regenerator 1 through the rare absorbent pipe 10 by the rare absorbent pump 22. Heat is passed through the heat exchanger 21 and the high-temperature heat exchanger 9, and is also warmed when branching from the rare absorption liquid pipe 10 and passing through the refrigerant drain heat recovery unit 12. The branch pipe 23 of the rare absorption liquid pipe 10 joins the rare absorption liquid pipe 10 on the downstream side of the refrigerant drain heat recovery device 12, and passes through the high-temperature heat exchanger 9 after the merge.

  In the absorption refrigerator configured as described above, the combustion amount of the burner 2 of the high-temperature regenerator 1 is adjusted according to the magnitude of the load. The combustion amount of the burner 2 is adjusted by changing the supply amount of fuel and air by the control valve 24. However, the proportional control can be appropriately performed corresponding to the load within a range where the load factor is 20% or more. In the low load range where the load factor is less than 20%, it has been difficult to respond appropriately. For this reason, regarding the control at a low load with a load factor of less than 20%, the combustion of the burner 2 is ON / OFF controlled without depending on the control valve 24.

  In the case of this combustion ON-OFF control of the burner 2, when the rated temperature at the cold water outlet of the cold / hot water pipe 17 is, for example, T ° C. during cooling operation, the burner 2 is turned off at a set temperature t1 ° C. lower than T ° C. When the combustion of the burner 2 is turned off at a set temperature t2 ° C. which is lower than T ° C. and slightly higher than the set temperature t1 ° C. (about 1 ° C.), a broken line in FIG. It will be in the state shown in.

  In a cooling operation, when the load is less than 20%, the temperature of the chilled water outlet can be kept low by setting the temperature higher by a predetermined temperature than the set temperature at the time of normal combustion OFF. The combustion amount of the burner required to turn on the combustion of this and return the cold water outlet temperature to the rated temperature can be kept low. Therefore, the average COP can be improved by the amount that can suppress the burner combustion amount.

  The refrigerant pump 14 can adjust the amount of refrigerant liquid sprayed from the refrigerant sprayer 16 to the cold / hot water pipe 17. At the time of low load in the cooling operation, there is often a simultaneous control for suppressing the amount of refrigerant liquid sent by the refrigerant pump 14 in conjunction with the control for suppressing the amount of refrigerant vapor generated in the high-temperature regenerator 1.

  For this reason, as shown in FIG. 4, the temperature of the cold water for switching the refrigerant pump 14 to OFF is set to a set temperature t4 ° C. indicated by a broken line that is lower by a predetermined temperature (for example, 1 ° C.) than the set temperature t3 ° C. indicated by the solid line. change. In this case, the minimum temperature of the cold water passing through the cold / hot water pipe 17 can be lowered by extending the operation of the refrigerant pump 14 during the low-load cooling operation of 20% or less. Thereby, by suppressing the combustion amount of the burner 2 of the high temperature regenerator 1 during the low load cooling operation to a low level, it is possible to contribute to the improvement of the average COP.

  As shown in FIG. 1, an inlet side temperature sensor 25 is installed on the evaporator inlet side of the cold / hot water pipe 17, and an outlet side temperature sensor 26 is installed on the evaporator outlet side, and returns to the evaporator 5 from a load not shown. The evaporator inlet temperature of the cold water is measured, and the evaporator outlet temperature of the cold water cooled by the evaporator 5 and supplied to the load is measured. When the difference between the cold water evaporator inlet temperature and the outlet temperature is equal to or lower than a predetermined temperature, and the state equal to or lower than the predetermined temperature continues for a predetermined time, when these data are input to a control device (not shown), The cooling operation has a low load and is determined to be during combustion ON-OFF control, and a signal for switching the combustion of the burner 2 of the high-temperature regenerator 1 to OFF is output.

  Also, the judgment method at the time of combustion ON-OFF control is that the difference between the evaporator inlet temperature and the outlet temperature of cold water is, for example, less than 15% of the rated temperature (guideline) and the duration is 30 minutes (guideline). it can. In this case, the state of less than 15% (standard) of the refrigeration capacity (cold water inlet / outlet temperature difference × cold water flow rate) may continue for 30 minutes (standard). FIG. 5 shows an example of the control chart. In the control chart, the cold water set temperature T1 is during cooling operation, and the cold water set temperature T1 + 1 ° C. is set higher by 1.0 ° C. than the cold water set temperature at low load. The warm water set temperature T2 is set during heating operation, and is set lower by 1.0 ° C. than the warm water set temperature T2 at a low load of 20% or less.

  In addition, the number of times the high temperature regenerator 1 is turned off and the number of times the refrigerant pump 14 connected to the evaporator 5 is turned off per predetermined time (standard 1 hour) is equal to or greater than the predetermined number (standard 3 times). In this case, it is possible to determine that the cooling operation has a low load and the combustion ON-OFF control is in progress. Further, by combining any of the above-described determination methods, it is possible to more appropriately determine the combustion ON-OFF control time during the cooling operation low load.

  On the other hand, at the time of heating operation, the open / close valve 28 provided in the middle of the refrigerant branch pipe 27 branched from the refrigerant pipe 7 and connected to the absorber 6 is opened and branched from the intermediate absorbent liquid pipe 8 to the absorber. The on-off valve 30 provided in the middle of the intermediate absorbing liquid branch pipe 29 connected to 6 is opened. Accordingly, the high-temperature refrigerant vapor evaporated and separated in the high-temperature regenerator 1 is supplied into the absorber 6 through the refrigerant branch pipe 27 having a low pressure, flows into the evaporator 5 side, and passes through the cold / hot water pipe 17. Hot water (hot water returned from the load) passing through the evaporator 5 is heated. The heated hot water is supplied to the load via the cold / hot water pipe 17 and used for heating.

  The refrigerant vapor radiated in the evaporator 5 condenses into a refrigerant liquid and accumulates at the bottom of the evaporator 5. The refrigerant liquid collected at the bottom of the evaporator 5 is branched in the middle of the refrigerant liquid pipe 15, and the open / close valve 32 provided in the middle of the refrigerant liquid branch pipe 31 connected to the absorber 6 is opened. Then, the refrigerant pump 14 supplies the refrigerant liquid branch pipe 31 to the bottom of the absorber 6.

  The intermediate absorbing liquid heated in the high temperature regenerator 1 and having an intermediate concentration is supplied to the absorber 6 through the intermediate absorbing liquid branch pipe 29 and collected at the bottom. The intermediate absorption liquid accumulated in the bottom part absorbs the refrigerant liquid supplied to the bottom part of the absorber 6 through the refrigerant liquid branch pipe 31 by the refrigerant pump 14 and becomes a rare absorption liquid. The rare absorbent is returned to the high temperature regenerator 1 via the rare absorbent pipe 10 by the rare absorbent pump 22 and is heated through the low temperature heat exchanger 21 and the high temperature heat exchanger 9 in the middle of the rare absorbent. . This is because the amount of combustion of the burner 2 in the high-temperature regenerator 1 is reduced by preheating the rare absorbent.

  Although the heating operation can be performed in this way, it is difficult to proportionally control the combustion amount of the burner 2 by the control valve 24 or the like when the heating load is within a low load range of 20% or less. For this reason, when the load factor is 20% or less, the combustion switch of the burner 2 is switched to ON-OFF control so as to cope with the low load heating operation.

  In the heating operation, particularly at a low load of 20% or less, the temperature is set lower by a predetermined temperature than the setting temperature at the time of conventional combustion OFF. This is because the average hot water outlet temperature when combustion is OFF tends to increase. By setting the set temperature at the time of combustion OFF low by a predetermined temperature (for example, about 1 ° C.), the burner combustion can be turned off early, and the rise in the hot water outlet temperature can be kept low. Thereby, improvement of average COP can be aimed at by suppressing the combustion amount of the burner 2 more than necessary.

  The determination method at the time of combustion ON-OFF control is that the difference between the evaporator inlet temperature and the outlet temperature of hot water passing through the evaporator 5 via the cold / hot water pipe 17 is equal to or higher than the predetermined temperature and equal to or higher than the predetermined temperature. The case where the state continues for a predetermined time, or the case where the heating capacity is equal to or higher than a predetermined ratio of the rating and the state exceeding the predetermined ratio continues for a predetermined time, or the high temperature regenerator 1 per predetermined time It is possible to adopt either the case where the number of times of combustion OFF is equal to or more than a predetermined number. Furthermore, it is possible to determine more appropriately by combining any of these determination methods.

  FIG. 2 is a block diagram showing a second embodiment of the absorption refrigerator according to the present invention. In the absorption refrigerator according to the second embodiment, the same components as those of the absorption refrigerator according to the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  The absorption refrigerator according to the second embodiment is different in that high-temperature (170 ° C. or higher) steam is used as a heat source for the high-temperature regenerator 33 instead of burner combustion. In this case, the steam pipe 34 is configured to pass through the inside of the high-temperature regenerator 33, and a steam control valve 35 is provided on the upstream side of the steam pipe 34. And the high temperature regenerator 33, the said low temperature regenerator 3, the condenser 4, the evaporator 5 through which the cold / hot water supplied to load passes through the cold / hot water pipe 17, the absorber 6, the refrigerant | coolant pump 14, and absorption At least liquid pumps 19 and 22 are provided.

  The absorption refrigerator configured as described above performs steam control valve ON / OFF control instead of burner combustion ON / OFF control in the absorption refrigerator of the first embodiment.

  Also in this case, similarly to the above, when the cooling operation is under a low load, the temperature of the chilled water for switching off the steam control valve 35 is set higher than the set temperature by a predetermined temperature, and the temperature of the chilled water for switching off the refrigerant pump 14 is also set. Setting a predetermined temperature higher than the set temperature, setting the temperature of the hot water for switching the combustion of the high-temperature regenerator OFF when the heating operation is under a low load, a predetermined temperature lower than the set temperature, etc. Can do.

  In addition, as a determination method of the ON / OFF control of the steam control valve 35, the difference between the evaporator inlet temperature and the outlet temperature of the cold water passing through the evaporator through the cold / hot water pipe is the predetermined temperature or less as described above. When the state below the predetermined temperature continues for a predetermined time, the cooling capacity becomes a predetermined ratio or less of the rated value, and when the state below the predetermined ratio continues for the predetermined time, the number of times of turning off the refrigerant pump per predetermined time is predetermined. The case where it becomes more than the number of times can be used.

  The present invention can improve the average COP when applied to a low-load operation with a load factor of 20% or less when air-conditioning is performed with an absorption refrigerator.

It is a lineblock diagram showing a 1st embodiment of an absorption refrigerating machine concerning the present invention. It is a block diagram which shows 2nd Embodiment of the absorption refrigerator which concerns on this invention. It is a graph which shows the cold water taking-out temperature at the time of combustion ON-OFF control of the burner of a high temperature regenerator at the time of cooling operation low load. It is a graph which shows the cold water taking-out temperature at the time of refrigerant pump ON-OFF control at the time of cooling operation low load. It shows an example of a control chart.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 High temperature regenerator 2 Burner 3 Low temperature regenerator 4 Condenser 5 Evaporator 6 Absorber 7 Refrigerant pipe 8 Intermediate absorption liquid pipe 9 High temperature heat exchanger 10 Rare absorption liquid pipe 11 Cooling water pipe 12 Refrigerant drain heat recovery device 13 Refrigerant liquid pipe DESCRIPTION OF SYMBOLS 14 Refrigerant pump 15 Refrigerant liquid pipe 16 Refrigerant spreader 17 Cold / hot water pipe 18 Absorbed liquid spreader 19 Concentrated liquid pump 20 Concentrated liquid pipe 21 Low temperature heat exchanger 22 Rare absorbent liquid pump 23 Branch pipe 24 Control valve 25 Inlet side temperature sensor 26 outlet side temperature sensor 27 refrigerant branch pipe 28 on-off valve 29 intermediate absorbing liquid branch pipe 30 on-off valve 31 refrigerant liquid branch pipe 32 on-off valve 33 high temperature regenerator 34 steam pipe 35 steam control valve

Claims (13)

  Absorption refrigerator comprising at least a high-temperature regenerator, a low-temperature regenerator, a condenser, an evaporator through which cold / hot water supplied to a load passes through a cold / hot water pipe, an absorber, a refrigerant pump and an absorption liquid pump An absorption chiller characterized in that the temperature of cold water for switching off the combustion of the high-temperature regenerator is set higher by a predetermined temperature than the set temperature when the cooling operation is under a low load.   The absorption chiller according to claim 1, wherein the temperature of the cold water for switching off the refrigerant pump is set lower than a set temperature by a predetermined temperature.   When the difference between the evaporator inlet temperature and the outlet temperature of the cold water passing through the evaporator through the cold / hot water pipe is equal to or lower than a predetermined temperature and the predetermined temperature or lower continues for a predetermined time, the cooling operation is reduced. The absorption refrigerator according to claim 1, wherein combustion of the high-temperature regenerator at the time of load is switched to OFF.   The absorption refrigerating machine according to claim 1, wherein combustion of the high-temperature regenerator is switched to OFF by combining claim 2 and claim 3.   The combustion of the high-temperature regenerator at the time of the cooling operation low load is switched to OFF when the cooling capacity is equal to or less than a predetermined ratio of the rating and the state of the predetermined ratio or less continues for a predetermined time. The absorption refrigerator described.   When the number of times of combustion OFF of the high-temperature regenerator per predetermined time and the number of times of turn-off of the refrigerant pump connected to the evaporator are equal to or more than a predetermined number of times, The absorption refrigerator according to claim 1, wherein combustion is switched off.   A combination of any two or more of claims 3, 5 and 6, wherein the combustion of the high-temperature regenerator at the time of the cooling operation low load is turned off or the operation of the refrigerant pump is turned off. The absorption refrigerator described.   Absorption refrigeration comprising at least a high temperature regenerator, a low temperature regenerator, a condenser, an evaporator through which cold / hot water supplied to a load passes through a cold / hot water pipe, an absorber, a refrigerant pump and an absorption liquid pump An absorption refrigeration machine, wherein the temperature of hot water for switching off combustion of the high-temperature regenerator is set lower than a set temperature by a predetermined temperature when the heating operation is under a low load.   When the difference between the evaporator inlet temperature and the outlet temperature of the hot water passing through the evaporator through the cold / hot water pipe is equal to or higher than a predetermined temperature, and the state of the predetermined temperature or higher continues for a predetermined time, the high temperature regenerator The absorption refrigerator according to claim 8, wherein the combustion of is switched to OFF.   9. The absorption refrigeration according to claim 8, wherein when the heating capacity is equal to or higher than a predetermined ratio of the rating and the state exceeding the predetermined ratio continues for a predetermined time, the combustion of the high-temperature regenerator is switched to OFF. Machine.   The combustion of the high temperature regenerator is switched off when both the number of times the high temperature regenerator burns off per predetermined time and the number of times the refrigerant pump connected to the evaporator turns off exceed a predetermined number. The absorption refrigerator according to claim 8, wherein   The absorption refrigerator according to claim 8, wherein two or more of any one of claims 9, 10, and 11 are combined to switch the combustion of the high-temperature regenerator to OFF.   The absorption refrigerating machine according to claim 1 or 8, wherein the high-temperature regenerator uses steam or hot water as a heat source instead of burner combustion.

Images