JP6385044B2 - Absorption refrigeration system - Google Patents

Description

  The present invention relates to an absorption refrigeration system.

  Conventionally, a solar heat utilization system including a solar heat collector that heats a heat medium by receiving sunlight and a heat storage tank that stores heat by introducing a heat medium heated by the solar heat collector has been proposed. . Also, in such a solar heat utilization system, a dilute solution is heated in a regenerator of an absorption refrigerator by connecting a pipe between the heat storage tank and the absorption refrigerator and circulating a heat medium between them. Also, an absorption refrigeration system used for the above has been proposed (see Patent Document 1).

  According to this absorption refrigeration system, the dilute solution can be heated using renewable energy called solar heat, and the fuel cost required for heating the dilute solution can be reduced. Furthermore, a heat storage tank is interposed between the solar heat collector and the absorption refrigerator, and this acts as a buffer. Can be supplied to an absorption refrigerator. That is, when the amount of solar radiation is small, if a heat medium is supplied directly from the solar heat collector to the absorption refrigerator, the heat medium having a low temperature will be supplied to the absorption refrigerator, and efficient operation will be performed. However, since a heat medium having a stable temperature can be supplied to the absorption refrigeration machine by providing the heat storage tank, an efficient operation can be performed.

JP 2012-127574 A

  In the absorption refrigeration system as described above, the absorption refrigeration unit is connected to the indoor unit by piping, and coolant is supplied to the indoor unit. Here, a cold storage tank for storing cold is provided on the pipe from the absorption chiller to the indoor unit.For example, when the solar radiation environment is good, the cold storage operation is performed in the absorption chiller and cold storage is performed by the cold storage tank. The following problems occur when trying to cool using cold energy stored in a cold storage tank when it is bad.

  First, when performing cooling using the cold energy of the cold storage tank, considering that heat is radiated in the cold storage tank after the cold storage until the cold heat is used, when performing cold storage, during normal cooling It is necessary to perform cold storage at a temperature lower than the temperature of the coolant in For this reason, the target temperature of the coolant in the piping from the absorption refrigerator to the indoor unit (cold storage tank) is lowered. However, if the target temperature of the coolant is lowered, the temperature of the coolant becomes lower than necessary during normal cooling, and it cannot be said that an efficient operation is performed.

  Furthermore, if the temperature of the coolant becomes lower than necessary, condensation may occur on the indoor unit side.

  Note that the above problem is not limited to the method of heating the heat medium by solar heat, but a system that heats the heat medium by using exhaust heat to store the heat medium, or by using renewable energy such as geothermal or biomass. This is a common problem even in an absorption refrigeration system having a system for storing heat by heating.

  Furthermore, the above problem is not limited to an absorption refrigeration system including an absorption chiller connected to an indoor unit, but an absorption refrigeration system including an absorption chiller connected to another external device such as an industrial cooling device. This is a common problem.

  The present invention has been made to solve such a conventional problem, and the object of the present invention is to enable more efficient operation and reduce the possibility of condensation. The object is to provide an absorption refrigeration system.

The absorption refrigeration system of the present invention comprises a heat collector that heats a heat medium with renewable energy that can be permanently used as an exhaust heat or energy source from equipment, and a heat medium that is heated by the heat collector. An absorption refrigerator that introduces and heats a dilute solution in a regenerator and obtains a cooling liquid by a circulation cycle of the regenerator, condenser, evaporator, and absorber, and cooling obtained by the absorption refrigerator The circulation flow path for circulating the liquid between the evaporator of the absorption refrigeration machine and the external device, the branch flow path branched from the circulation flow path, and the flow direction of the coolant flowing through the circulation flow path are switched. A switching valve that flows into the branch flow path, and a cold storage that is provided on the branch flow path, introduces the cooling liquid obtained by the absorption chiller , stores the cold, and supplies the stored cold heat to the external device. When the tank and the specified conditions are met, A cool storage operation signal is transmitted to the absorption refrigerator, and the controller prohibits transmission of the cool storage operation signal when the predetermined condition is not satisfied, and when the controller transmits the cool storage operation signal, The switching valve is controlled to cause the coolant from the absorption chiller to flow into the branch flow path, and the absorption chiller receives the cold storage operation signal from the controller and transfers the coolant to the branch flow path. to supply the cold storage tank via, than the case of supplying the cooling liquid not received the cold-storage operation signal from the controller to the external apparatus without passing through the branch flow path, the target temperature of the cooling liquid It is characterized by lowering.

  According to the absorption refrigeration system of the present invention, when a predetermined condition is satisfied, a cold storage operation signal is transmitted to the absorption refrigerator, and when the predetermined condition is not satisfied, transmission of the cold storage operation signal is prohibited, When the cold storage operation signal is received from the controller, the target temperature of the coolant in the flow path from the absorption chiller to the external device is lowered than when the cold storage operation signal is not received from the controller. For this reason, when performing a cold storage operation, the target temperature of the coolant can be lowered, preventing the coolant temperature from becoming lower than necessary during normal cooling operation and deteriorating the operation efficiency. can do. Furthermore, when performing a cold storage operation, the target temperature of the coolant is lowered, so that the coolant having a temperature lower than necessary during normal cooling is not supplied to the external device, and condensation may occur in the external device. Will be reduced. Therefore, it is possible to provide an absorption refrigeration system that enables more efficient operation and can reduce the possibility of condensation.

  In the absorption refrigeration system of the present invention, the absorption refrigeration system further includes a cold storage tank temperature sensor that detects a cold storage temperature of the cold storage tank, and the absorption refrigerator is receiving the cold storage operation signal, the cold storage tank When the cold storage temperature detected by the temperature sensor is equal to or higher than the first predetermined value, a cold storage operation is started in which the cooling liquid is introduced into the cold storage tank for cold storage, and the cold storage temperature detected by the cold storage tank temperature sensor is It is preferable that the cold storage operation is stopped when the temperature is equal to or lower than a second predetermined value lower than the predetermined value.

  According to this absorption refrigeration system, when the absorption chiller receives a cold storage operation signal, the absorption chiller is installed in the cold storage tank when the cold storage temperature detected by the cold storage tank temperature sensor is equal to or higher than the first predetermined value. The cold storage operation for introducing the coolant and storing the cold is started. Further, the cold storage operation is stopped when the cold storage temperature detected by the cold storage tank temperature sensor is equal to or lower than a second predetermined value lower than the first predetermined value. For this reason, the cold storage operation is performed in a state where sufficient cold heat cannot be secured in the cold storage tank, and the cold storage operation is stopped when sufficient cold heat is secured in the cold storage tank, preventing unnecessary cold storage operation. can do.

Further, the control method of the absorption refrigeration system according to the present invention includes a heat collector that heats a heat medium by renewable energy that can be permanently used as an exhaust heat or energy source from the device, and a heating by the heat collector. An absorption refrigerator that heats the diluted solution in the regenerator by introducing the heated heat medium and obtains a cooling liquid by a circulation cycle of the regenerator, the condenser, the evaporator, and the absorber, and the absorption refrigerator A circulation flow path for circulating the obtained cooling liquid between the evaporator of the absorption chiller and an external device, a branch flow path branched from the circulation flow path, and a cooling liquid flowing through the circulation flow path A switching valve that switches the flow direction of the refrigerant to flow into the branch flow channel, and is provided on the branch flow channel, introduces a cooling liquid obtained by the absorption refrigeration machine , stores the cold, and stores the stored heat. a cold storage tank to supply the equipment, the absorption cold A control method for an absorption refrigeration system comprising: a controller for transmitting a cold storage operation signal to the machine; and a controller for prohibiting the transmission, from the controller to the absorption chiller when a predetermined condition is satisfied The first step of transmitting a cold storage operation signal to the second step, the second step of prohibiting transmission of the cold storage operation signal when the predetermined condition is not satisfied, and the switching when the cold storage operation signal is transmitted in the first step. A cool storage operation signal is transmitted from the controller to the absorption refrigerator in the third step of controlling the valve to allow the coolant from the absorption refrigerator to flow into the branch flow path, and in the first step. when supplying cooling liquid to the cold storage tank through the branch flow path, the branch flow coolant not cold-storage operation signal is transmitted to the absorption chiller from the controller in the second step Than the case of supplying to the external device without using, characterized in that it comprises a fourth step of lowering the target temperature of the cooling liquid.

  According to this control method for an absorption refrigeration system, when a predetermined condition is satisfied, a cold storage operation signal is transmitted to the absorption chiller, and when the predetermined condition is not satisfied, transmission of the cold storage operation signal is prohibited. When the cold storage operation signal is received from the controller, the target temperature of the coolant in the flow path from the absorption refrigerator to the external device is lowered as compared with the case where the cold storage operation signal is not received from the controller. For this reason, when performing a cold storage operation, the target temperature of the coolant can be lowered, preventing the coolant temperature from becoming lower than necessary during normal cooling operation and deteriorating the operation efficiency. can do. Furthermore, when performing a cold storage operation, the target temperature of the coolant is lowered, so that the coolant having a temperature lower than necessary during normal cooling is not supplied to the external device, and condensation may occur in the external device. Will be reduced. Therefore, it is possible to provide an absorption refrigeration system that enables more efficient operation and can reduce the possibility of condensation.

  According to the present invention, it is possible to provide an absorption refrigeration system that enables more efficient operation and can reduce the possibility of condensation.

1 is a schematic configuration diagram of an absorption refrigeration system according to an embodiment of the present invention. It is a schematic block diagram which shows an example of an absorption refrigerator. It is a figure which shows control of the heat collecting pump which concerns on this embodiment. It is a figure explaining operation of an absorption refrigerating machine at the time of normal cooling operation. It is a figure explaining operation | movement of the absorption refrigeration system at the time of cool storage operation, (a) shows operation | movement of an absorption refrigeration machine, (b) has shown operation | movement of the whole system. It is a flowchart which shows the process in the system controller of the absorption refrigeration system which concerns on this embodiment, Comprising: The process of transmission of a cool storage operation signal and prohibition is shown. It is a flowchart which shows the process in the system controller of the absorption refrigeration system which concerns on this embodiment, Comprising: The process of the switching valve is shown.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the drawings. FIG. 1 is a schematic configuration diagram of an absorption refrigeration system according to an embodiment of the present invention. As shown in FIG. 1, an absorption refrigeration system 1 according to the present embodiment heats a diluted solution of an absorption refrigeration machine 21 using solar heat, and includes a first system 10 and a second system 20. And a third system 30.

  The first system 10 heats a heat medium using solar heat, and includes a solar heat collector (heat collector) 11, a heat storage tank 12, a heat collection channel 13, and a heat collection pump 14. I have. In the present embodiment, the first system 10 heats the heat medium using solar heat, but is not limited thereto, and may heat the heat medium using exhaust heat. Further, the heating medium may be heated using renewable energy (one that can be permanently used as an energy source) such as geothermal or biomass.

  The solar heat collector 11 heats the heat medium by receiving sunlight, and is installed at a position where it is easy to receive sunlight, such as on a roof. As the heat medium, water, antifreeze, propylene glycol aqueous solution, or the like is used.

  The heat storage tank 12 introduces a heat medium heated by the solar heat collector 11 and stores heat. The heat storage tank 12 may be a tank that stores the heat medium therein, or may be one that stores heat of the introduced heat medium using a heat storage material.

  In addition, when the heat storage tank 12 stores heat with a heat storage material, for example, magnesium hydroxide is used as the heat storage material, but is not limited thereto. Furthermore, when the heat medium is water and the heat storage tank 12 is a tank that stores water therein, the heat storage tank 12 may function as a so-called hot water storage tank, and hot water may be supplied to a home or the like. In addition, the heat storage tank 12 may be of a type including a heat exchanger.

  The heat collection channel 13 is a pipe that circulates the heat medium from the heat storage tank 12 through the solar heat collector 11 to the heat storage tank 12 again. Among these, the flow path from the heat storage tank 12 to the solar heat collector 11 is referred to as a first heat collection flow path 13a, and the flow path from the solar heat collector 11 to the heat storage tank 12 is referred to as a second heat collection flow path 13b.

  The heat collection pump 14 is provided in the first heat collection flow path 13a of the heat collection flow path 13, and serves as a power source for circulating the heat medium from the heat storage tank 12 through the solar heat collector 11 to the heat storage tank 12 again. It is.

  In such a first system 10, the heat medium circulates through the heat collecting flow path 13 by operating the heat collecting pump 14. The heat medium is heated by the solar heat collector 11, reaches the heat storage tank 12 through the second heat collection flow path 13 b, and is stored in the heat storage tank 12.

  The second system 20 supplies a heat medium heated in a heat storage tank 12 and a heat medium heated through a heat storage material to the absorption refrigeration machine 21, and includes the absorption refrigeration machine 21 and the heat medium. A flow path 22 and a heat medium pump 23 are provided.

  The absorption refrigerator 21 heats a dilute solution in a regenerator, and obtains a cooling liquid by a circulation cycle of the regenerator, a condenser, an evaporator, and an absorber.

  FIG. 2 is a schematic configuration diagram illustrating an example of the absorption refrigerator 21. Specifically, the regenerator 101 includes, for example, water serving as a refrigerant (hereinafter, the refrigerant vaporized is referred to as refrigerant vapor, and the refrigerant liquefied is referred to as liquid refrigerant), and lithium bromide (absorbent liquid) ( A dilute solution (solution having a low concentration of the absorbing solution) mixed with LiBr) is heated. The regenerator 101 is provided with a heat medium flow path 22, and a dilute solution is sprayed on the heat medium flow path 22 and heated. The regenerator 101 generates a refrigerant vapor and a concentrated solution (a solution having a high concentration of absorption liquid) by releasing the vapor from the dilute solution by this heating.

  The condenser 102 liquefies the refrigerant vapor supplied from the regenerator 101. A first cold water heat transfer tube 102a is inserted into the condenser 102. Cooling water is supplied to the first cold water heat transfer tube 102a from a cooling tower or the like, and the evaporated refrigerant vapor is liquefied by the cooling water in the first cold water heat transfer tube 102a. Further, the liquid refrigerant liquefied by the condenser 102 is supplied to the evaporator 103.

  The evaporator 103 evaporates the liquid refrigerant. In this evaporator 103, the 2nd cold water heat exchanger tube (circulation flow path) 31 connected to an indoor unit (an example of an external device) is provided. The second cold water heat transfer tube 31 is connected to, for example, an indoor unit, and water warmed by cooling by the indoor unit flows. Further, the inside of the evaporator 103 is in a vacuum state. For this reason, the evaporating temperature of the water which is a refrigerant | coolant will be about 5 degreeC. Therefore, the liquid refrigerant sprayed on the second cold water heat transfer tube 31 evaporates depending on the temperature of the second cold water heat transfer tube 31. Further, the temperature of the water in the second cold water heat transfer tube 31 is deprived of the temperature by evaporation of the liquid refrigerant. Thereby, the water of the 2nd cold water heat exchanger tube 31 will be supplied to an indoor unit as cold water (an example of a cooling fluid), and an indoor unit will supply cold air indoors using cold water.

  The absorber 104 absorbs the refrigerant evaporated in the evaporator 103. A concentrated solution is supplied from the regenerator 101 into the absorber 104, and the evaporated refrigerant is absorbed by the concentrated solution to generate a diluted solution. The absorber 104 is inserted with a third cold water heat transfer tube 104a. The cooling water flows through the third cold water heat transfer tube 104a, and the absorbed heat generated by the absorption of the refrigerant of the concentrated solution is removed by the cooling water of the third cold water heat transfer tube 104a. The third cold water heat transfer tube 104a is connected to the first cold water heat transfer tube 102a. Moreover, the absorber 104 supplies the regenerator 101 with the dilute solution whose density | concentration fell by absorption of the refrigerant | coolant by the pump 104b.

  In addition, although the 2nd cold water heat exchanger tube 31 is connected to the indoor unit in the above, it is not restricted to this, You may connect with an industrial cooling device etc. In the following description, an indoor unit will be described as an example of an external device.

  Further, the absorption chiller 21 includes a control unit 105. The control unit 105 includes a CPU (Central Processing Unit) and controls the entire absorption refrigerator 21. The control unit 105 is configured to change the control content based on a signal from a system controller 44 described later.

  Refer to FIG. 1 again. The heat medium flow path 22 is a pipe that circulates the heat medium from the heat storage tank 12 through the regenerator 101 of the absorption refrigerator 21 to the heat storage tank 12 again. Among these, the flow path from the heat storage tank 12 to the regenerator 101 of the absorption chiller 21 is referred to as a first heat medium flow path 22a, and the flow path from the regenerator 101 of the absorption refrigeration machine 21 to the heat storage tank 12 is the first. This is referred to as two heat medium flow path 22b.

  The heat medium pump 23 is provided in the first heat medium flow path 22 a of the heat medium flow path 22, and circulates the heat medium from the heat storage tank 12 to the heat storage tank 12 again through the regenerator 101 of the absorption refrigerator 21. It becomes a power source to be made.

  The third system 30 is a part that sends out the coolant obtained by the absorption refrigerator 21 to the indoor unit or performs cold storage using the coolant, and the second cold water heat transfer pipe 31 (hereinafter referred to as circulation). In addition to the flow path 31, a regenerator 32, first and second switching valves 33 a and 33 b, first to fourth branch flow paths 34 a to 34 d, and a circulation pump 35 are provided.

  The above-described circulation flow path 31 is a flow path for circulating cold water obtained by the absorption chiller 21 between the evaporator 103 of the absorption chiller 21 and the indoor unit. Among the circulation channels 31, a channel from the absorption chiller 21 to the indoor unit is referred to as a first circulation channel 31a, and a channel from the indoor unit to the absorption chiller 21 is referred to as a second circulation channel 31b. Called.

  The cold storage tank 32 is provided on a flow path (first and second branch flow paths 34 a, 34 b) branched from the first circulation flow path 31 a among the circulation flow paths 31, and obtained by the absorption refrigerator 21. Cold water is introduced to store cold.

  The cold storage tank 32 may be a tank that stores cold water therein, or may store cold heat of the introduced cold water using a cold storage material. In addition, when the cool storage tank 32 is what cools with a cool storage material, the cool storage material is, for example, a mixture of water and a gel agent (natural polymer), but is not particularly limited thereto. In addition, the cold storage tank 32 may be of a type including a heat exchanger.

  The first switching valve 33a is a three-way valve provided on the first circulation channel 31a, and the first and second ports A and B are located on the first circulation channel 31a. One end of the first branch channel 34 a is connected to the third port C of the first switching valve 33 a, and the other end is connected to the inlet of the regenerator 32. For this reason, the 1st switching valve 33a will switch the route (AB) which supplies the cold water from the absorption refrigeration machine 21 to an indoor unit, and the route (AC) which supplies the cool storage tank 32.

  The second switching valve 33 b is a three-way valve provided on the outlet side of the cold storage tank 32. The second branch channel 34b has one end connected to the outlet of the regenerator 32 and the other end connected to the first port D of the second switching valve 33b. The third branch channel 34c has one end connected to the second port E of the second switching valve 33b and the other end connected to the second circulation channel 31b. The fourth branch pipe 34d has one end connected to the third port F of the second switching valve 33b and the other end connected to the downstream side of the first switching valve 33a of the first circulation channel 31a. For this reason, the 2nd switching valve 33b will switch the route (D-E) which returns the cold water from the cool storage tank 32 to the 2nd circulation flow path 31b, and the route (DF) which supplies an indoor unit.

  The circulation pump 35 is provided at a position downstream of the connection point between the second circulation channel 31 b and the third branch channel 34 c in the second circulation channel 31 b, and the evaporator 103 of the absorption chiller 21. To the power source for circulating cold water to the evaporator 103 of the absorption refrigerator 21 again through the indoor unit. In addition, when the first and second switching valves 33a and 33b are controlled and the AC route and the DE route are selected, the circulation pump 35 does not supply cold water to the indoor unit without absorbing it. It becomes a power source for circulating cold water through the refrigerator 21 and the cold storage tank 32.

  Furthermore, the absorption refrigeration system 1 according to the present embodiment includes a collector temperature sensor 41, a heat storage tank temperature sensor 42, a cold storage tank temperature sensor 43, and a system controller (controller) 44.

  The heat collector temperature sensor 41 detects the temperature of the heat medium from the solar heat collector 11, and transmits a signal corresponding to the heat medium temperature to the system controller 44. The heat storage tank temperature sensor 42 detects the temperature of the heat medium in the heat storage tank 12 (heat storage temperature), and transmits a signal corresponding to the heat medium temperature to the system controller 44. The cold storage tank temperature sensor 43 detects the temperature of the cold water in the cold storage tank 32 (cold storage temperature), and transmits a signal corresponding to the cold water temperature to the system controller 44.

  The system controller 44 includes a CPU and controls the entire absorption refrigeration system 1. In particular, the system controller 44 according to the present embodiment has a function of transmitting a cold storage operation signal to the control unit 105 of the absorption chiller 21 or prohibiting the transmission. When the cold storage operation signal is received, the target temperature of the coolant (hereinafter referred to as the outlet) in the flow path from the absorption chiller 21 to the indoor unit (that is, the first circulation flow path 31a) is greater than when the cold storage operation signal is not received. Reduce target temperature.

  Next, a control method of the absorption refrigeration system 1 according to the present embodiment will be described. FIG. 3 is a diagram illustrating control of the heat collecting pump 14 according to the present embodiment.

  First, it is assumed that the heat collection pump 14 is stopped. In this state, the system controller 44 inputs a signal from the heat collector temperature sensor 41 and a signal from the heat storage tank temperature sensor 42. Next, the system controller 44 calculates the differential temperature based on these signals. This differential temperature is obtained by subtracting the temperature detected by the heat storage tank temperature sensor 42 from the temperature detected by the heat collector temperature sensor 41. Next, the system controller 44 determines whether or not the temperature difference is equal to or higher than T1 ° C. shown in FIG. 3. When it is determined that the temperature difference is equal to or higher than T1 ° C., the heat collecting pump 14 is operated (ON) and is determined not to be higher than T1 ° C. In this case, the heat collecting pump 14 is kept stopped (OFF).

  After the operation of the heat collecting pump 14, the system controller 44 inputs signals from the heat collector temperature sensor 41 and the heat storage tank temperature sensor 42 and calculates a differential temperature. Then, the system controller 44 determines whether the temperature difference is equal to or lower than T2 ° C. shown in FIG. When the system controller 44 determines that the temperature is equal to or lower than T2 ° C., the system controller 44 stops the heat collecting pump 14 (OFF). When the system controller 44 determines that the temperature is not lower than T2 ° C., the system controller 44 keeps the heat collecting pump 14 in an operating state (ON).

  In addition, about the said temperature difference, you may employ | adopt values, such as a moving average.

  Moreover, the absorption refrigerator 21 performs a normal cooling operation and a cold storage operation. When the normal cooling operation and the cold storage operation are performed, that is, when the absorption refrigeration machine 21 is not stopped, the system controller 44 operates the heat medium pump 23 to transfer the heat medium from the heat storage tank 12. The refrigerating machine 101 of the absorption refrigerator 21 is supplied. Thereby, the heat medium from the heat storage tank 12 is used for heating the dilute solution in the regenerator 101.

  Further, the absorption refrigeration system 1 operates as follows during normal cooling operation. FIG. 4 is a diagram for explaining the operation of the absorption refrigerator 21 during the normal cooling operation. As shown in FIG. 4, the control unit 105 of the absorption refrigerator 21 stores a temperature adjustment stop temperature T3 ° C. and a temperature adjustment start temperature T4 ° C. during normal cooling operation. Further, the third system 30 includes a temperature sensor (not shown) that detects the temperature of the coolant in the flow path from the absorption chiller 21 to the indoor unit (hereinafter referred to as outlet temperature). The absorption refrigerator 21 is controlled based on the signal from the temperature sensor.

  That is, when the outlet temperature detected by the temperature sensor during the normal cooling operation of the absorption refrigerator 21 becomes equal to or lower than the temperature adjustment stop temperature T3 ° C., the control unit 105 temporarily stops the operation. Further, the control unit 105 resumes the operation when the outlet temperature becomes equal to or higher than the temperature adjustment start temperature T4 ° C. during the temporary stop. During the temporary stop, the circulation pump 35 is operating and the cold water is circulated.

  Further, during the cold storage operation, the absorption refrigeration system 1 operates as follows. FIG. 5 is a diagram for explaining the operation of the absorption refrigeration system 1 during the cold storage operation, where (a) shows the operation of the absorption refrigeration machine 21 and (b) shows the operation of the entire system 1. As shown in FIG. 5A, the control unit 105 of the absorption refrigerator 21 stores a temperature adjustment stop temperature T5 ° C. and a temperature adjustment start temperature T6 ° C. during the cold storage operation. Here, the temperature adjustment stop temperature T5 ° C. during the cold storage operation is lower than the temperature adjustment stop temperature T3 ° C. during the normal cooling operation, and the temperature adjustment start temperature T6 ° C. during the cold storage operation is the temperature adjustment start during the normal cooling operation. The temperature is lower than T4 ° C.

  When the outlet temperature detected by the temperature sensor during the cold storage operation of the absorption refrigerator 21 is equal to or lower than the temperature adjustment stop temperature T5 ° C., the control unit 105 temporarily stops the operation. In addition, when the outlet temperature becomes equal to or higher than the temperature adjustment start temperature T6 ° C. during the temporary stop, the control unit 105 resumes the operation. During the temporary stop, the circulation pump 35 is operating and the cold water is circulated.

  Further, the system controller 44 stores a cold storage operation end temperature T7 ° C. (second predetermined value) and a cold storage operation start temperature T8 ° C. (first predetermined value) shown in FIG. Here, the cool storage operation end temperature T7 ° C is higher than the temperature control stop temperature T5 ° C during the cool storage operation. The cold storage operation start temperature T8 ° C. is the same as the temperature adjustment start temperature T6 ° C. during the cold storage operation, and is lower than the temperature control start temperature T4 ° C. during the normal cooling operation.

  When the cold storage temperature detected by the cold storage tank temperature sensor 43 during the cold storage operation becomes equal to or lower than the cold storage operation end temperature T7 ° C., the system controller 44 stops the entire system 1 (except for the operation of the heat collection pump 14). That is, the operation of the heat medium pump 23 and the circulation pump 35 stops, and the absorption refrigerator 21 stops the production of cold water by the circulation cycle.

  Further, the system controller 44 starts the operation of the entire system when the cold storage temperature detected by the cold storage tank temperature sensor 43 becomes equal to or higher than the cold storage operation start temperature T8 ° C. while the entire system is stopped. That is, the heat medium pump 23 and the circulation pump 35 start operation, and in the absorption refrigerator 21, cold water is obtained by the circulation cycle.

  Further, the system controller 44 determines whether or not to perform a cold storage operation, and outputs a cold storage operation signal to the control unit 105 of the absorption chiller 21 when it is determined to perform the cold storage operation. When receiving the cold storage operation signal, the control unit 105 of the absorption refrigerator 21 shifts the control content from the one shown in FIG. 4 to the one shown in FIG. That is, when the control unit 105 receives the cold storage operation signal, the control unit 105 lowers the target outlet temperature than when the cold storage operation signal is not received.

  Whether or not the cool storage operation signal can be transmitted is referred to a timer in the system controller 44, and if the cool storage operation date or the cool storage operation time zone (an example of a predetermined condition), the cool storage operation signal is transmitted and the normal air conditioning day or normal Transmission of the cold storage operation signal is prohibited during the air conditioning time period.

  In addition, the system controller 44 also executes control of the first and second switching valves 33a and 33b. That is, the system controller 44 controls the first switching valve 33a to select the A-B route during the normal cooling operation, and controls the second switching valve 33b to select the D-E route. Further, the system controller 44 controls the first switching valve 33a to select the A-C route during the cold storage operation, and controls the second switching valve 33b to select the D-E route.

  Furthermore, the indoor unit can also be cooled by cold water supplied from the cold storage tank 32. For this reason, when performing cooling operation using the cold water in the cold storage tank 32, the system controller 44 controls the first switching valve 33a to select the AC route and also controls the second switching valve 33b. To select the DF route.

  FIG. 6 is a flowchart showing processing in the system controller 44 of the absorption refrigeration system 1 according to the present embodiment, and shows processing for transmitting and prohibiting a cold storage operation signal. 6 is executed until the entire system 1 is stopped.

  First, the system controller 44 makes a timer determination (S1). As a result of the timer determination, when the current time is the cold storage operation day or the cold storage operation time zone (an example of the predetermined condition) (S1: the cold storage operation date or the cold storage operation time zone), the system controller 44 absorbs the cold storage operation signal. 21 (S2), and then the processing shown in FIG. 6 proceeds to step S1.

  On the other hand, if the result of the timer determination indicates that the current time is a normal air conditioning day or a normal air conditioning time zone (S1: normal air conditioning date or normal air conditioning time zone), the system controller 44 has a current air conditioning load, that is, a cooling operation from the user. Is judged (S3). If there is currently no air conditioning load (S3: NO), the system controller 44 transmits a cold storage operation signal to the absorption chiller 21 (S2), and then the processing shown in FIG. 6 proceeds to step S1.

  If there is a current air conditioning load (S3: YES), the system controller 44 prohibits transmission of the cold storage operation signal (S4), and then the processing shown in FIG. 6 proceeds to step S1.

  FIG. 7 is a flowchart showing processing in the system controller 44 of the absorption refrigeration system 1 according to this embodiment, and shows processing of the switching valves 33a and 33b. 7 is executed until the entire system 1 is stopped.

  First, the system controller 44 determines whether it is during a cold storage operation (S11). Whether or not it is during the cold storage operation may be determined based on whether or not the cold storage operation signal is transmitted in step S2 of FIG. 6, or may be determined in the same manner as the timer determination as in step S1 of FIG. May be.

  When it is determined that the cold storage operation is being performed (S11: YES), the system controller 44 controls the first switching valve 33a to select the AC route, and controls the second switching valve 33b to control D-E. A route is selected (S12). That is, by selecting the above route, the system controller 44 circulates between the absorption chiller 21 and the cold storage tank 32 without supplying cold water to the indoor unit. Then, the processing shown in FIG. 7 proceeds to step S11.

  In this case, the control unit 105 of the absorption refrigeration machine 21 decreases the target outlet temperature as shown in FIGS. 4 and 5A.

  On the other hand, when it is determined that it is not during the cold storage operation (S11: NO), the system controller 44 determines whether it is during the normal cooling operation (S13). In this case, for example, based on a signal from the cold storage tank temperature sensor 43, the system controller 44 determines that the normal cooling operation is being performed when the cold storage temperature of the cold storage tank 32 exceeds a predetermined temperature (S13: YES). If not, it is determined that it is not during normal cooling operation (S13: NO).

  If it is determined that it is during normal cooling operation (S13: YES), the system controller 44 controls the first switching valve 33a to select the A-B route and also controls the second switching valve 33b. The DE route is selected (S14). That is, by selecting the above route, the system controller 44 circulates between the absorption refrigerator 21 and the indoor unit without supplying cold water to the cold storage tank 32. Then, the processing shown in FIG. 7 proceeds to step S11.

  When it is determined that it is not during normal cooling operation (S13: NO), the system controller 44 determines whether to perform cooling operation using the cold water in the cold storage tank 32 (S15). In this case, for example, based on a signal from the cold storage tank temperature sensor 43, the system controller 44 determines that the cooling using the cold water in the cold storage tank 32 is performed when the cold storage temperature of the cold storage tank 32 is equal to or lower than a predetermined temperature. (S15: YES), otherwise, it is determined not to perform cooling using the cold water in the cold storage tank 32 (S15: NO).

  If it is determined that the cooling using the cold water in the cold storage tank 32 is performed (S15: YES), the system controller 44 controls the first switching valve 33a to select the AC route and the second switching. The valve 33b is controlled to select the DF route (S16). That is, by selecting the above route, the system controller 44 circulates cold water between the absorption chiller 21 and the indoor unit through the cold storage tank 32. Then, the process shown in FIG. 7 ends.

  On the other hand, when it is determined not to perform cooling using the cold water in the cold storage tank 32 (S15: NO), the process proceeds to step S11.

  Thus, according to the absorption refrigeration system 1 according to the present embodiment, when a predetermined condition is satisfied, a cold storage operation signal is transmitted to the absorption refrigeration machine 21, and when the predetermined condition is not satisfied. In the case where the transmission of the cold storage operation signal is prohibited and the cold storage operation signal is received from the system controller 44, the absorption refrigerator 21 is directed to the indoor unit more than the case where the cold storage operation signal is not received from the system controller 44. The target temperature of the coolant in the 1 circulation channel 31a is lowered. For this reason, when performing a cold storage operation, the target temperature of the coolant can be lowered, preventing the coolant temperature from becoming lower than necessary during normal cooling operation and deteriorating the operation efficiency. can do. Furthermore, when performing the cold storage operation, the target temperature of the cooling liquid is lowered, so that the cooling liquid having a temperature lower than necessary during normal cooling is not supplied to the indoor unit, and condensation may occur in the indoor unit. Will be reduced. Therefore, it is possible to provide the absorption refrigeration system 1 that enables more efficient operation and can reduce the possibility of condensation.

  Moreover, when the absorption refrigerator 21 is receiving the cool storage operation signal, when the cool storage temperature detected by the cool storage tank temperature sensor 43 is equal to or higher than the cool storage operation start temperature T8 ° C., the absorption cooler 21 supplies the coolant to the cool storage tank 21. To start cold storage operation. Further, when the cold storage temperature detected by the cold storage tank temperature sensor 43 is equal to or lower than the cold storage operation stop temperature T7 ° C. lower than the cold storage operation start temperature T8 ° C., the cold storage operation is stopped. For this reason, the cold storage operation is performed in a state where sufficient cold heat cannot be secured in the cold storage tank 32, and the cold storage operation is stopped when sufficient cold heat is secured in the cold storage tank 32, and wasteful cold storage operation is performed. Can be prevented.

  As described above, the present invention has been described based on the embodiment, but the present invention is not limited to the above embodiment, and may be modified without departing from the gist of the present invention.

  For example, the above-described temperatures T1 to T8 ° C. can be appropriately changed, and the heights between the temperatures T1 to T8 ° C. can be appropriately changed. Needless to say, when the external device is not an indoor unit but an industrial cooling device, the normal cooling operation can be read as normal cooling operation. Furthermore, even when the external device is another device other than the indoor unit and the industrial cooling device, the various terms described above can be appropriately replaced.

  Further, in the above embodiment, the cold storage operation signal is transmitted assuming that the predetermined condition is satisfied when the current day is the cold storage operation day or the cold storage operation time zone, but the predetermined condition is not limited to the above, and can be appropriately changed. is there. For example, a predetermined condition may be that the cold storage operation instruction of the system controller 44 has been pressed or the like, and other conditions may be set as the predetermined condition.

DESCRIPTION OF SYMBOLS 1 ... Absorption-type refrigeration system 10 ... 1st system 11 ... Solar thermal collector (heat collector)
DESCRIPTION OF SYMBOLS 12 ... Heat storage tank 13 ... Heat collection flow path 14 ... Heat collection pump 20 ... 2nd system 21 ... Absorption type refrigerator 22 ... Heat medium flow path 23 ... Heat transfer medium pump 30 ... 3rd system 31 ... Circulation flow path 32 ... Cold storage tank 33a, 33b ... switching valves 34a-34d ... branch passage 35 ... circulation pump 41 ... heat collector temperature sensor 42 ... heat storage tank temperature sensor 43 ... cool storage tank temperature sensor 44 ... system controller (controller)

Claims (3)

A heat collector that heats the heat medium with renewable energy that is permanently available as waste heat or energy source from the equipment;
An absorption refrigerator that introduces a heat medium heated by the heat collector and heats a dilute solution in the regenerator, and obtains a cooling liquid by a circulation cycle of the regenerator, the condenser, the evaporator, and the absorber; ,
A circulation passage for circulating the coolant obtained by the absorption refrigerator between the evaporator of the absorption refrigerator and an external device;
A branch channel branched from the circulation channel;
A switching valve for switching the flow direction of the coolant flowing through the circulation flow path to flow into the branch flow path;
A cold storage tank that is provided on the branch flow path, cools the refrigerant obtained by the absorption chiller and cools it, and supplies the stored cold energy to the external device ;
A controller that transmits a cold storage operation signal to the absorption refrigerator when the predetermined condition is satisfied, and a controller that prohibits transmission of the cold storage operation signal when the predetermined condition is not satisfied,
When the controller transmits the cold storage operation signal, the controller controls the switching valve to flow the coolant from the absorption chiller into the branch flow path,
When the absorption refrigerator receives the cold storage operation signal from the controller and supplies the coolant to the cold storage tank via the branch flow path, the absorption refrigerator does not receive the cold storage operation signal from the controller. It said than that supplied to the external equipment, absorption refrigerating system and decreases the target temperature of the cooling fluid without passing through the branch flow path. A cold storage tank temperature sensor for detecting the cold storage temperature of the cold storage tank;
In the case where the absorption refrigerator receives the cold storage operation signal, the absorption refrigerator introduces coolant into the cold storage tank when the cold storage temperature detected by the cold storage tank temperature sensor is equal to or higher than a first predetermined value. The cold storage operation is started, and the cold storage operation is stopped when the cold storage temperature detected by the cold storage tank temperature sensor becomes equal to or lower than a second predetermined value lower than the first predetermined value. Item 6. The absorption refrigeration system according to Item 1. A heat collector that heats the heat medium with renewable energy that is permanently available as waste heat or energy source from the equipment;
An absorption refrigerator that introduces a heat medium heated by the heat collector and heats a dilute solution in the regenerator, and obtains a cooling liquid by a circulation cycle of the regenerator, the condenser, the evaporator, and the absorber; ,
A circulation passage for circulating the coolant obtained by the absorption refrigerator between the evaporator of the absorption refrigerator and an external device;
A branch channel branched from the circulation channel;
A switching valve for switching the flow direction of the coolant flowing through the circulation flow path to flow into the branch flow path;
A cold storage tank that is provided on the branch flow path, cools the refrigerant obtained by the absorption chiller and cools it, and supplies the stored cold energy to the external device ;
A controller for transmitting a cold storage operation signal to the absorption refrigerator and prohibiting the transmission;
An absorption refrigeration system control method comprising:
A first step of transmitting a cold storage operation signal from the controller to the absorption chiller when a predetermined condition is satisfied;
A second step of prohibiting transmission of a cold storage operation signal when the predetermined condition is not satisfied;
When the cold storage operation signal is transmitted in the first step, the third step of controlling the switching valve to flow the coolant from the absorption refrigerator into the branch channel;
When the cool storage operation signal is transmitted from the controller to the absorption refrigerator in the first step and the coolant is supplied to the cool storage tank via the branch flow path, the controller from the controller in the second step A fourth step of lowering the target temperature of the coolant than when the cool storage operation signal is not transmitted to the absorption refrigerator and the coolant is supplied to the external device without passing through the branch flow path ;
An absorption refrigeration system control method comprising:

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