Control device and air conditioning system control method

Abstract

The present disclosure provides: a control device that appropriately adjusts the use of waste heat of a power generation device in a configuration in which the waste heat thereof is used as a heat source for an absorption-type refrigerator and hot water supply; and a control method for the absorption-type refrigerator.　The control device according to the present disclosure comprises: an acquisition unit that acquires the temperature of hot waster water supplied to a heat exchanger that uses a hot water supply and the operation state of a hot water supply pump that supplies water to the heat exchanger that uses the hot water supply; and a control unit. When the temperature of the hot waste water is higher than a temperature threshold value and the hot water supply pump is in operation, the control unit permits the supply of the hot waster water to the heat exchanger that uses the hot water supply, and when the temperature of the hot waster water is equal to or less than the temperature threshold value or when the hot water supply pump is not in operation, the control unit prohibits the supply of the hot waster water to the heat exchanger that uses the hot water supply.

Description

Control device and control method for air conditioning system

[0001] The present disclosure relates to a control device and a control method for an air conditioning system.

[0002] Patent Document 1 discloses an absorption chiller that utilizes waste heat from a power generation device.

[0003] Japanese Patent Application Laid-Open No. 2018-141564

[0004] The present disclosure provides a control device and a control method for an absorption chiller that appropriately adjusts the use of waste heat in a configuration in which waste heat from a power generation device is used as a heat source for an absorption chiller and hot water supply.

[0005] This specification includes the entire contents of Japanese Patent Application No. 2023-123214, filed on July 28, 2023. A control device in the present disclosure is provided in an air conditioning system including at least an absorption chiller that uses waste hot water heated by waste heat from a power generation unit as a heat source, and a hot water heat exchanger that heats water using the waste heat from the power generation unit as a heat source, and includes an acquisition unit that acquires the temperature of the waste hot water supplied to the hot water heat exchanger and the operating state of a hot water pump that supplies the water to the hot water heat exchanger, and a control unit, wherein the control unit permits the supply of the waste hot water to the hot water heat exchanger when the temperature of the waste hot water is higher than a temperature threshold and the hot water pump is operating, and prohibits the supply of the waste hot water to the hot water heat exchanger when the temperature of the waste hot water is equal to or lower than the temperature threshold or when the hot water pump is not operating.

[0006] The control method for an air conditioning system disclosed herein is a control method for an air conditioning system that includes at least an absorption chiller that uses waste hot water heated by waste heat from a power generation unit as a heat source, and a hot water heat exchanger that heats water using the waste heat from the power generation unit as a heat source, wherein a control device acquires the temperature of the waste hot water supplied to the hot water heat exchanger and the operating status of a hot water pump that supplies the water to the hot water heat exchanger, and when the temperature of the waste hot water is higher than a temperature threshold and the hot water pump is operating, the control device allows the supply of the waste hot water to the hot water heat exchanger, and when the temperature of the waste hot water is below the temperature threshold or when the hot water pump is not operating, the control device prohibits the supply of the waste hot water to the hot water heat exchanger.

[0007] The control device and the control method for an air conditioning system according to the present disclosure appropriately limit the use of waste heat from a power generation unit for hot water supply in an air conditioning system that uses waste heat from a power generation unit as a heat source for an absorption chiller and hot water supply. Thus, in a configuration in which waste heat from a power generation unit is used as a heat source for an absorption chiller and hot water supply, the use of waste heat can be appropriately adjusted.

[0008] FIG. 1 is a schematic diagram of an air conditioning system according to the first embodiment. FIG. 2 is a diagram of an absorption chiller according to the first embodiment. FIG. 3 is a flowchart showing the operation of an air conditioning control device according to the first embodiment.

[0009] (Knowledge forming the basis of the present disclosure) At the time the inventors came up with the present disclosure, there was a technology for utilizing waste heat from a power generation device that drives a generator using an engine or the like in an absorption chiller. Technology for utilizing waste heat from a generator or the like in a hot water supply device was also known. However, the inventors discovered a problem in that when waste heat is utilized in both an absorption chiller and a hot water supply device, it is difficult to appropriately adjust the amount of waste heat utilized by each device. To solve this problem, the inventors came up with the subject matter of the present disclosure. Therefore, the present disclosure provides a control device and a control method for an absorption chiller that appropriately adjust the utilization of waste heat in a configuration in which waste heat from a power generation device is utilized as a heat source for the absorption chiller and hot water supply.

[0010] Hereinafter, embodiments will be described in detail with reference to the drawings. However, more detailed description than necessary may be omitted. For example, detailed description of already well-known matters or redundant description of substantially the same configuration may be omitted. Note that the accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter described in the claims.

[0011] (Embodiment 1) [1-1. Configuration] [1-1-1. Configuration of Air Conditioning System] Fig. 1 is a schematic configuration diagram of an air conditioning system 1 in Embodiment 1. The air conditioning system 1 is configured by connecting a power generation device 4 and a device that utilizes the waste heat of the power generation device 4 via a waste heat supply path 7. Fig. 1 shows a heating heat exchanger 5, a hot water heat exchanger 6, and an absorption chiller 10 as devices that utilize the waste heat. The air conditioning system 1 may have any number of power generation devices 4 and absorption chillers 10. The configuration and number of devices that utilize the waste heat are also any number. In this embodiment, as an example, a configuration will be described in which the air conditioning system 1 includes three power generation devices 4, heating heat exchangers 5, hot water heat exchangers 6, and two absorption chillers 10.

[0012] The power generation device 4 is a device that generates electricity by driving a generator 41 with a drive source. The drive source may be, for example, a gas engine or a diesel engine, and the type is not particularly limited. In this embodiment, an example is shown in which an engine 42 is used as the drive source.

[0013] The air conditioning system 1 recovers waste heat from the engine 42 of the power generation device 4 using a heat medium flowing through the waste heat supply path 7. For example, the power generation device 4 includes a radiator 43 that dissipates heat from the engine 42. The heat medium flowing through the waste heat supply path 7 is supplied to the radiator 43 by a pump 71. The radiator 43 exchanges heat between the waste heat of the engine 42 and the heat medium flowing through the waste heat supply path 7. The heat medium flowing through the waste heat supply path 7 is, for example, water, and may contain antifreeze, a rust inhibitor, or other additives. The water flowing through the waste heat supply path 7 is heated in the radiator 43 by the waste heat of the engine 42 and becomes hot water, which is then supplied to the heating utilization heat exchanger 5, the hot water utilization heat exchanger 6, and the absorption chiller 10. The hot water flowing through the waste heat supply path 7 is called waste hot water.

[0014] The radiator 43 may be configured to directly exchange heat between the water flowing through the waste heat supply path 7 and the engine 42. Alternatively, the radiator 43 may be configured to exchange heat between the water flowing through the waste heat supply path 7 and the cooling water of the engine 42.

[0015] The power generation device 4 may be a cogeneration system that utilizes the waste heat of the engine 42, for example, in a water heater. In this case, the radiator 43 exchanges heat between the heat medium that supplies the waste heat of the engine 42 to the waste heat utilization device and the water flowing through the waste heat supply path 7. As a result, the waste heat of the engine 42 that has been utilized in the power generation device 4 is supplied through the waste heat supply path 7.

[0016] The air conditioning system 1 includes a plurality of power generation units 4. The power generation units 4 are connected in parallel to a waste heat supply path 7. With this configuration, the waste heat of each power generation unit 4 is supplied to the heating heat exchanger 5, the hot water heat exchanger 6, and the absorption chiller 10 through the waste heat supply path 7.

[0017] The heating-utilization heat exchanger 5 is connected to the absorption chiller 10, and uses waste heat from the power generation device 4 to provide supplementary heating during heating operation of the absorption chiller 10. The waste heat supply path 7 is provided with a heating three-way valve 72 that switches between supplying and cutting off hot water from the waste heat supply path 7 to the heating-utilization heat exchanger 5.

[0018] The hot water heat exchanger 6 heats water for hot water supply using waste heat from the power generation device 4. Waste hot water is supplied to the hot water heat exchanger 6 through the waste heat supply path 7, while waste hot water is supplied through the hot water pipe 6A by the hot water pump 61. The hot water heat exchanger 6 heats the water flowing through the hot water pipe 6A with the waste heat from the power generation device 4 by exchanging heat between the waste hot water in the waste heat supply path 7 and the water flowing through the hot water pipe 6A. The water heated in the hot water heat exchanger 6 is supplied to a hot water supply device (not shown) connected to the hot water pipe 6A. The hot water pump 61 operates in conjunction with the operating state of the hot water supply device connected to the hot water pipe 6A. For example, if the temperature of the waste hot water in the hot water storage tank of the hot water supply device drops, the hot water pump 61 operates to supply the waste hot water heated in the hot water heat exchanger 6 to the hot water supply device. The waste heat supply path 7 is provided with a hot water three-way valve 76 that switches between supplying and blocking waste hot water from the waste heat supply path 7 to the hot water utilization heat exchanger 6 .

[0019] The absorption chiller 10 is a device that supplies chilled water and hot water for air conditioning by utilizing waste heat from the power generation unit 4. The absorption chiller 10 is also called an absorption chiller / heater. The absorption chiller 10 is connected to a hot water supply pipe 73 that branches off from the waste heat supply path 7, and waste hot water is supplied to the regenerator 15 of the absorption chiller 10 through the hot water supply pipe 73. The hot water supply pipe 73 is provided with a three-way valve 74 that switches between supplying and cutting off the waste hot water from the hot water supply pipe 73 to the absorption chiller 10.

[0020] In the air conditioning system 1 shown in FIG. 1 , the symbols T1, T2, T4, T5, T6, T7, T8, T9, and T10 indicate temperature sensors. In the following description, the temperature detected by the temperature sensor T1 will be referred to as temperature T1. The same applies to the temperature sensors T2, T5, T6, T9, and T10. The temperature sensor T1 is located downstream of the power generation unit 4 and upstream of the heating-utilization heat exchanger 5 in the flow direction of the waste hot water in the waste heat supply path 7. The temperature sensor T1 can detect the temperature of the waste hot water heated by the waste heat of the power generation unit 4. The temperature sensor T4 is located between the heating-utilization heat exchanger 5 and the absorption chiller 10 and detects the temperature of the waste hot water immediately before it flows from the waste heat supply path 7 into the absorption chiller 10. In controlling the absorption chiller 10, the temperature detected by the temperature sensor T4 is used as the temperature of the waste hot water supplied from the power generation unit 4 to the absorption chiller 10. The temperature sensor T5 is located between the absorption chiller 10 and the hot water heat exchanger 6 in the flow direction of the waste heat supply path 7. The temperature detected by the temperature sensor T5 is the temperature of the waste hot water supplied to the hot water heat exchanger 6.

[0021] 1-1-2. Configuration of the Control System of the Air Conditioning System The air conditioning system 1 includes an air conditioning control device 2 that controls the absorption chiller 10 , and a power generation control device 3 that controls the power generation device 4 .

[0022] The multiple power generation devices 4 of the air conditioning system 1 are each connected to the power generation control device 3 by a communication line 1C. The power generation control device 3 controls the power generation devices 4. Control by the power generation control device 3 includes, for example, starting, operating, and stopping the power generation devices 4. There is no limit to the number of power generation devices 4 that the power generation control device 3 controls. The power generation control device 3 can operate all of the power generation devices 4 that are the subject of control by the power generation control device 3, operate only some of them, or stop all of the power generation devices 4.

[0023] The power generation control device 3 determines the number of power generation devices 4 to operate, depending on the utilization state of waste heat in the heating utilization heat exchanger 5 , the hot water utilization heat exchanger 6 , and the absorption chiller 10 , for example.

[0024] The power generation control device 3 is connected to the pump 71 via a communication line (not shown). The power generation control device 3 operates the pump 71 corresponding to the power generation device 4 that is to be operated, among the power generation devices 4 connected to the power generation control device 3. This is one example, and the pump 71 may be configured to start and stop operation in conjunction with the start and stop of operation of the power generation device 4, for example.

[0025] The air conditioning control device 2 is connected to each absorption chiller 10 constituting the air conditioning system 1 via a communication line 1B.

[0026] As shown in Fig. 1, the air conditioning control device 2 includes a control unit 201 and a storage unit 202. The control unit 201 is a computer including a CPU (Central Processing Unit), an MPU (Micro Processor Unit), a microcontroller, or another processor. The control unit 201 includes the above-mentioned processor, a ROM (Read Only Memory), and a RAM (Random Access Memory), and controls the absorption chiller 10 by executing a program using the processor. The storage unit 202 has a non-volatile storage area and stores the program executed by the processor and data processed by the processor.

[0027] The control unit 201 is connected to a communication unit 221, an input unit 222, and a display unit 223. The communication unit 221 is a communication device having a transmitter and a receiver. The communication unit 221 is connected to the power generation control device 3 via a communication line 1A. The communication unit 221 transmits and receives various signals and data to and from the power generation control device 3 in accordance with the control of the control unit 201. The communication unit 221 is connected to each absorption chiller 10 via a communication line 1B. The communication unit 221 transmits various signals and data related to the control of the absorption chiller 10 to the absorption chiller 10 in accordance with the control of the control unit 201.

[0028] The communication unit 221 is connected via communication lines (not shown) to the heating three-way valve 72, the three-way valve 74, the hot water supply three-way valve 76, the pump 51, and the hot water supply pump 61. The communication unit 221 operates each of the heating three-way valve 72, the three-way valve 74, and the hot water supply three-way valve 76 under the control of the control unit 201.

[0029] For example, when the heating-utilizing heat exchanger 5 is in an operable state, the communication unit 221 operates the heating three-way valve 72 to enable supply of waste hot water from the waste heat supply path 7 to the heating-utilizing heat exchanger 5. This allows the heating-utilizing heat exchanger 5 to utilize the waste heat of the power generation device 4. The communication unit 221 can also operate the heating three-way valve 72 to block the supply of waste hot water from the waste heat supply path 7 to the heating-utilizing heat exchanger 5. In this case, the heating-utilizing heat exchanger 5 cannot utilize the waste heat of the power generation device 4. Similarly, for example, when the hot water-utilizing heat exchanger 6 is in an operable state, the communication unit 221 operates the hot water-utilizing three-way valve 76 to enable supply of waste hot water from the waste heat supply path 7 to the hot water-utilizing heat exchanger 6. This allows the hot water-utilizing heat exchanger 6 to utilize the waste heat of the power generation device 4. In addition, the communication unit 221 can also operate the hot water three-way valve 76 to block the supply of waste hot water from the waste heat supply path 7 to the hot water utilization heat exchanger 6, in which case the hot water utilization heat exchanger 6 will be unable to utilize the waste heat from the power generation device 4.

[0030] The input unit 222 accepts input operations by an operator who manages the air conditioning control device 2. The input unit 222 outputs an operation signal indicating the input content to the control unit 201. The input unit 222 may be configured to accept input using, for example, another computer installed in a location different from the air conditioning control device 2.

[0031] The display unit 223 displays information related to the control performed by the air conditioning control device 2. The display unit 223 includes a display device such as a liquid crystal display, an LED (Light Emitting Diode) indicator, or other display device. The display unit 223 displays information corresponding to the operating state of the air conditioning control device 2 and the operating state of the absorption chiller 10.

[0032] The control unit 201 includes an acquisition unit 211 and a processing unit 212. The acquisition unit 211 and the processing unit 212 may be functional units configured by a processor executing a program.

[0033] The acquisition unit 211 acquires temperatures detected by the temperature sensors T1, T2, T4, T5, T6, T7, T8, T9, and T10. The processing unit 212 controls the air conditioning system 1 based on information acquired by the communication unit 221 through communication, input received by the input unit 222, and the detected temperatures acquired by the acquisition unit 211. For example, the processing unit 212 controls the operation of the absorption chiller 10 based on temperatures T1, T4, T13, and T14 indicating the temperature of the waste hot water supplied to the absorption chiller 10 from the waste heat supply path 7. The processing unit 212 also transmits information regarding the number of operating power generation units 4 to the power generation control device 3 based on the temperature of the waste hot water supplied to the absorption chiller 10, etc. Details of the operation of the control unit 201 will be described later with reference to a flowchart.

[0034] 2 is a configuration diagram of the absorption chiller 10 according to embodiment 1. The absorption chiller 10 is a water chiller / heater that supplies chilled water and hot water by using water as a refrigerant and an aqueous solution of lithium bromide (LiBr) as an absorbing liquid.

[0035] The absorption chiller 10 includes an evaporator 11, an absorber 12 arranged in parallel with the evaporator 11, an evaporator-absorber shell 13 housing the evaporator 11 and the absorber 12, a regenerator 15, and a condenser 16. The absorption chiller 10 also includes an indoor unit 17, a cooler 18, a gas burner 20, a dilute absorbent pump 31, a refrigerant pump 32, a concentrated absorbent pump 33, and a cooling water pump 35. In the absorption chiller 10, the above-mentioned components are connected by piping via a concentrated absorbent pipe 21, a dilute absorbent pipe 22, refrigerant pipes 23, 24, and 25, a cooling water pipe 26, a cold water pipe 27, and the like, to form a circulation path. The heating-use heat exchanger 5 shown in FIG. 2 may also be included in the configuration of the absorption chiller 10.

[0036] The pressure inside the evaporator-absorber barrel 13 is kept at a high vacuum state, and water, which serves as a refrigerant, evaporates in the evaporator 11 and moves inside the evaporator-absorber barrel 13 to the absorber 12. The water forms a liquid pool 11A at the bottom of the evaporator 11. The evaporator-absorber barrel 13 is provided with a refrigerant pipe 25 that opens at the bottom of the evaporator 11, and the end of the refrigerant pipe 25 is connected to a sprayer arranged above the evaporator 11. A refrigerant pump 32 is provided on the refrigerant pipe 25. The refrigerant pump 32 transports the water from the liquid pool 11A to the top of the evaporator 11, thereby spraying water inside the evaporator 11.

[0037] The evaporator 11 is connected to the indoor unit 17 via a chilled water pipe 27. The chilled water flowing through the chilled water pipe 27 exchanges heat with the air in a heat exchanger (not shown) of the indoor unit 17, and the chilled air is supplied to the room, thereby realizing cooling operation. The indoor unit 17 acts as a heat load for the absorption chiller 10.

[0038] Chilled water (brine) is circulated between the evaporator 11 and the indoor unit 17 through a chilled water pipe 27. A heat transfer pipe 27A formed as part of the chilled water pipe 27 is arranged inside the evaporator 11, and during cooling operation of the absorption chiller 10, the brine flowing through the heat transfer pipe 27A exchanges heat with the refrigerant and is cooled. During heating operation of the absorption chiller 10, the brine is heated in the heat transfer pipe 27A and sent to the indoor unit 17 through the chilled water pipe 27. A pump 51 for transporting the brine is provided in the chilled water pipe 27.

[0039] In the cold water pipe 27, a heating-utilization heat exchanger 5 is connected via a hot water pipe 5A to a path for circulating brine from the indoor unit 17 to the evaporator 11. The heating-utilization heat exchanger 5 exchanges heat between the brine returning from the indoor unit 17 to the evaporator 11 and the waste hot water flowing through the waste heat supply path 7.

[0040] As shown in FIG. 2 , the chilled water pipe 27 is provided with temperature sensors T7, T8, T13, and T14. Hereinafter, the temperature detected by the temperature sensor T7 will be referred to as temperature T7, and the same applies to the temperature sensors T8, T13, and T14. The temperature sensor T8 is disposed in the path where water flows from the indoor unit 17 to the heating-use heat exchanger 5, and the temperature sensor T7 is disposed in the path where water flows from the heating-use heat exchanger 5 to the evaporator 11. The temperature sensor T13 is disposed between the heating-use heat exchanger 5 and the evaporator 11 and detects the temperature of the brine flowing into the heat transfer pipe 27A. The temperature detected by the temperature sensor T13 is referred to as the inlet water temperature T13. The temperature sensor T14 is disposed between the evaporator 11 and the indoor unit 17 and detects the temperature of the brine flowing from the heat transfer pipe 27A to the indoor unit 17. The temperature detected by the temperature sensor T14 is referred to as the outlet water temperature T14. The inlet water temperature T13 corresponds to an example of a "chilled water inlet temperature," and the outlet water temperature T14 corresponds to an example of a "chilled water outlet temperature."

[0041] The absorber 12 has the function of absorbing the refrigerant vapor evaporated in the evaporator 11 into an absorbing liquid and maintaining the pressure inside the evaporator-absorber shell 13 at a high vacuum state. A dilute absorbent liquid reservoir 12A is formed in the lower part of the absorber 12 to accumulate dilute absorbent liquid that has absorbed the refrigerant vapor. One end of a dilute absorbent liquid pipe 22 having a dilute absorbent liquid pump 31 is connected to the dilute absorbent liquid reservoir 12A. The dilute absorbent liquid pump 31 is an inverter-controllable pump, and is configured so that the drive amount of the dilute absorbent liquid pump 31 can be varied by controlling the inverter frequency.

[0042] The dilute absorbent pipe 22 is provided between the absorber 12 and the regenerator 15 and opens into the inside of the regenerator 15. A hot water supply pipe 73 branching off from the waste heat supply path 7 is connected to the regenerator 15, and a heat transfer pipe 73A formed in a part of the hot water supply pipe 73 is disposed inside the regenerator 15.

[0043] The regenerator 15 uses the waste heat of the power generation device 4 and the gas burner 20 as heat sources for heating and regenerating the absorbent. Inside the regenerator 15, the dilute absorbent sent through the dilute absorbent pipe 22 forms an absorbent reservoir 15A. The heat transfer pipe 73A heats the absorbent reservoir 15A with waste hot water sent through the hot water supply pipe 73, thereby heating and regenerating the absorbent. The gas burner 20 is housed in a shell (not shown) attached to the regenerator 15. The gas burner 20 heats the absorbent reservoir 15A with a flame, thereby heating and regenerating the absorbent. The ignition and extinguishing of the gas burner 20 and the flow rate of the fuel gas supplied to the gas burner 20 are controlled by the air conditioning control device 2. For example, when there is insufficient heat from the heat transfer pipe 73A, the air conditioning control device 2 causes the gas burner 20 to perform heating to promote the thermal regeneration of the absorbent. The heat transfer tube 73A is a first heat source that heats the absorption liquid by utilizing waste heat from the power generation device 4, and the gas burner 20 is a second heat source. Under the control of the air conditioning control device 2, the absorption chiller 10 can be operated using only the heat transfer tube 73A as a heat source, or using both the heat transfer tube 73A and the gas burner 20 as heat sources.

[0044] One end of a concentrated absorption liquid pipe 21 is connected to the regenerator 15. The other end of the concentrated absorption liquid pipe 21 is connected to a sprayer provided at the top of the absorber 12. A concentrated absorption liquid pump 33 is provided on the concentrated absorption liquid pipe 21. The concentrated absorption liquid pump 33 sends the concentrated absorption liquid from the regenerator 15 to the absorber 12, and the sent concentrated absorption liquid is sprayed inside the absorber 12 by the sprayer.

[0045] One end of a refrigerant pipe 23 opens at the top of the regenerator 15. The other end of the refrigerant pipe 23 opens into the interior of the condenser 16, and the refrigerant separated from the dilute absorption liquid in the regenerator 15 is sent to the condenser 16 through the refrigerant pipe 23.

[0046] The absorber 12 and the condenser 16 are provided with cooling water pipes 26 for circulating cooling water sequentially through the absorber 12 and the condenser 16. The cooling water pipes 26 are connected to a cooler 18. The cooler 18 is, for example, a cooling tower, and cools the cooling water flowing through the cooling water pipes 26. A cooling water pump 35 is provided in the cooling water pipes 26. The cooling water cooled by the cooler 18 is transported to the absorber 12 by the cooling water pump 35, and cools the concentrated absorption liquid sprayed inside the absorber 12. The cooling water pipes 26 are arranged inside the condenser 16, and cool the water vapor in the condenser 16.

[0047] The above is the flow of the absorption liquid and refrigerant when the absorption chiller 10 performs cooling operation, and when the absorption chiller 10 performs heating operation, the on-off valve 37 provided on the cooling water pipe 26 is closed. In this case, water vapor heated in the regenerator 15 flows into the evaporator 11 without condensing in the condenser 16, and heats the heat transfer pipe 27A. As a result, the brine flowing through the heat transfer pipe 27A becomes hot, and this brine flows into the indoor unit 17, supplying hot water for heating.

[0048] During heating operation of the absorption chiller 10, the heating three-way valve 72 ( FIG. 1 ) is opened under the control of the air conditioning control device 2. With the heating three-way valve 72 open, waste hot water is supplied from the waste heat supply path 7 to the heating-utilizing heat exchanger 5, and heat is exchanged between the waste hot water and the brine. In this way, the heating-utilizing heat exchanger 5 heats the brine returning from the indoor unit 17 to the evaporator 11 with the waste heat of the power generation device 4, thereby achieving the effect of improving the heating efficiency of the absorption chiller 10.

[0049] The dilute absorbent pump 31, the refrigerant pump 32, the concentrated absorbent pump 33, the cooling water pump 35, and the on-off valve 37 are connected to the air conditioning control device 2 via control lines (not shown). The air conditioning control device 2 controls the above-mentioned components to cause the absorption chiller 10 to perform cooling operation and heating operation.

[0050] As shown in FIG. 1 , the air conditioning control device 2 is connected to each absorption chiller 10 included in the air conditioning system 1 via a communication line 1B. The air conditioning control device 2 individually controls the multiple absorption chillers 10 to perform cooling operation and heating operation. For example, when the air conditioning control device 2 receives an input from the input unit 222 of an instruction to start the absorption chiller 10, the air conditioning control device 2 starts operation of the absorption chiller 10. Furthermore, while the absorption chiller 10 is operating, the air conditioning control device 2 calculates an air conditioning load based on the inlet water temperature T13 and the outlet water temperature T14, and controls the operating state of the absorption chiller 10 in accordance with the calculated air conditioning load. Furthermore, for example, the air conditioning control device 2 controls the cooling water pump 35 and the on-off valve 37 to switch the absorption chiller 10 between cooling operation and heating operation.

[0051] [1-2. Operation of Air Conditioning System] Next, we will explain the operation of the air conditioning control device 2. The operation of the air conditioning control device 2 explained here relates to the process of controlling the opening and closing of the hot water supply three-way valve 76. The hot water supply three-way valve 76 corresponds to an example of a "valve," and the air conditioning control device 2 corresponds to an example of a "control device."

[0052] In this embodiment, the air conditioning control device 2 controls the open / close state of the hot water three-way valve 76 in accordance with the usage state of the hot water utilization heat exchanger 6. The open / close states of the hot water three-way valve 76 include an ON state and an OFF state. The ON state is a state in which waste hot water as a heat medium flowing through the waste heat supply path 7 flows to the hot water utilization heat exchanger 6, and can be referred to as a fully open state. The OFF state is a state in which waste hot water flowing through the waste heat supply path 7 does not flow to the hot water utilization heat exchanger 6, and can be referred to as a fully closed state. The hot water three-way valve 76 is configured to be switchable between two states, the ON state and the OFF state, under the control of the air conditioning control device 2. The hot water three-way valve 76 may also be controllable between the ON state and the OFF state. That is, the hot water three-way valve 76 may be able to be opened to any degree between a fully open state and a fully closed state. In this case, the air conditioning control device 2 controls the opening degree of the hot water supply three-way valve 76 to a fully open state, a fully closed state, or any opening degree between the fully open state and the fully closed state. The opening degree of the hot water supply three-way valve 76 roughly corresponds to the flow rate of waste hot water flowing from the waste heat supply path 7 to the hot water utilization heat exchanger 6. Therefore, controlling the opening degree of the hot water supply three-way valve 76 can be said to control the flow rate of waste hot water.

[0053] Furthermore, the air conditioning control device 2 can be configured to determine whether to prioritize the hot water heat exchanger 6 when the hot water heat exchanger 6 and another waste heat utilization device use the waste heat of the power generation device 4. This setting is called a priority setting. The air conditioning control device 2 performs the priority setting according to the contents of the input received by, for example, the input unit 222. The contents of the priority setting are stored in the memory unit 202. An example of the other waste heat utilization device is a device that uses waste hot water as a heat source. The following describes, as an example, a case where the other waste heat utilization device is an absorption chiller 10. There is no limitation on the air conditioning system 1, in which devices other than the absorption chiller 10 are used as the other waste heat utilization device.

[0054] 3 is a flowchart showing the operation of the air conditioning control device 2 in embodiment 1. In FIG. 3, steps S11 and S14 are executed by the acquisition unit 211, and the other steps are executed by the processing unit 212.

[0055] The air conditioning control device 2 acquires the temperature of the waste hot water (step S11). Specifically, the air conditioning control device 2 acquires the temperature T5 detected by the temperature sensor T5. The air conditioning control device 2 determines whether the temperature T5 of the waste hot water is higher than a preset temperature threshold (step S12).

[0056] If the temperature T5 is equal to or lower than the temperature threshold value (step S12: NO), the air conditioning control device 2 turns off the hot water supply three-way valve 76 (step S13) and ends this process.

[0057] If the air conditioning control device 2 determines that the temperature T5 is higher than the temperature threshold (step S12: YES), it acquires the operating status of the hot water pump 61 (step S14). The hot water pump 61 is a pump that operates in conjunction with the use of a hot water supply device (not shown) connected to the hot water supply pipe 6A. Therefore, the operating status of the hot water pump 61, i.e., whether it is operating or stopped, corresponds to the usage status of the hot water supply device. For example, the hot water pump 61 operates when the temperature of the hot water in the hot water storage tank of the hot water supply device drops. The air conditioning control device 2 may also control the hot water pump 61. In the hot water utilization heat exchanger 6, the waste hot water supplied to the hot water utilization heat exchanger 6 from the waste heat supply path 7 is the heat medium on the heat source side, and the water supplied to the hot water utilization heat exchanger 6 by the hot water pump 61 can be considered the water on the user side.

[0058] The air conditioning control device 2 determines whether the hot water supply pump 61 is operating (step S15). If the hot water supply pump 61 is not operating (step S15: NO), the air conditioning control device 2 proceeds to step S13.

[0059] If the hot water supply pump 61 is operating (step S15: YES), the air conditioning control device 2 switches the hot water supply three-way valve 76 to the ON state (step S16). Thereafter, the air conditioning control device 2 starts PID control based on the temperature T9 detected by the temperature sensor T9 (step S17). The PID control started in step S17 is referred to as control (A).

[0060] Temperature sensor T9 is a sensor located downstream of hot water heat exchanger 6 in hot water pipe 6A, and detects the temperature of water flowing toward the hot water supply device after passing through hot water heat exchanger 6. In other words, detected temperature T9 is the temperature at the outlet side of hot water heat exchanger 6. The PID control started in step S17 is control that determines the opening degree of hot water three-way valve 76 so that detected temperature T9, which is the temperature of water after passing through hot water heat exchanger 6, becomes a predetermined target temperature TD.

[0061] After starting the control of step S17, the air conditioning control device 2 refers to the priority setting and determines whether or not the hot water heat exchanger 6 has been set to have priority (step S18). If the priority setting indicates that the hot water heat exchanger 6 has been set to have priority (step S18: YES), the air conditioning control device 2 proceeds to step S19. If the priority setting indicates that the hot water heat exchanger 6 has not been set to have priority, that is, if the absorption chiller 10 has been set to have priority (step S18: NO), the air conditioning control device 2 proceeds to step S20.

[0062] In step S19, the air conditioning control device 2 sets the control target value a to a preset low temperature setting value (step S19), and proceeds to step S22, which will be described later.

[0063] In step S20, the air conditioning control device 2 determines whether the absorption chiller 10 is in cooling operation (step S20). If the absorption chiller 10 is not in cooling operation (step S20: NO), the air conditioning control device 2 proceeds to step S19. If the absorption chiller 10 is in cooling operation (step S20: YES), the air conditioning control device 2 proceeds to step S21.

[0064] In step S21, the air conditioning control device 2 sets the control target value a to a preset high temperature setting value (step S21), and proceeds to step S22, which will be described later.

[0065] The low temperature setting value is a specific temperature that is preset as a target value for PID control. The high temperature setting value is a specific temperature that is preset as a target value for PID control, or a temperature calculated using preset parameters. The low temperature setting value is a temperature lower than the high temperature setting value. For example, the low temperature setting value is set to 65.0 [°C], and the high temperature setting value is set to (Tr + 5.0) [°C]. Tr is a parameter that serves as a reference for the high temperature setting value and can be changed by input via the input unit 222, and as a specific example, Tr is set to 70.

[0066] In step S22, the air conditioning control device 2 starts PID control based on the temperature T6 detected by the temperature sensor T6 using the target value a (step S22). The temperature sensor T6 is a sensor located downstream of the hot water heat exchanger 6 in the waste heat supply path 7, and detects the temperature of the waste hot water downstream of the position where the waste hot water after passing through the hot water heat exchanger 6 returns to the waste heat supply path 7. The more waste heat used in the hot water heat exchanger 6, the lower the temperature T6 detected by the temperature sensor T6, and vice versa. The PID control started in step S22 is referred to as control (B).

[0067] When the hot water utilization heat exchanger 6 is given priority over the absorption chiller 10, the air conditioning control device 2 sets the target value a of the detected temperature T6, which is the temperature of the waste hot water after passing through the hot water utilization heat exchanger 6, to a low setting value. This allows the temperature of the waste hot water that passes through the hot water utilization heat exchanger 6 and returns to the waste heat supply path 7 to be low. In other words, the hot water utilization heat exchanger 6 is allowed to use a large amount of waste heat for hot water supply. On the other hand, when the absorption chiller 10 is given priority over the hot water utilization heat exchanger 6, the air conditioning control device 2 sets the target value a of the detected temperature T6 to a high setting value. This allows the temperature of the waste hot water flowing from the waste heat supply path 7 to the power generation device 4 to be higher than when the target value a is set to a low setting value. As a result, the temperature of the waste hot water circulating through the waste heat supply path 7 and flowing into the absorption chiller 10 is higher, allowing the absorption chiller 10 to use more waste heat.

[0068] After step S22, the air conditioning control device 2 controls the hot water supply three-way valve 76 based on the control value of control (A) started in step S17 and the control value of control (B) started in step S22 (step S23). Specifically, the air conditioning control device 2 acquires the control value of control (A) and the control value of control (B) in step S23. The control value of PID control is, specifically, the amount of change in the opening of the hot water supply three-way valve 76, that is, the amount of change that changes the opening of the hot water supply three-way valve 76.

[0069] In step S23, the air conditioning control device 2 performs so-called low-select control on the two acquired control values. That is, the air conditioning control device 2 adopts the smaller of the two control values ​​and operates the hot water supply three-way valve 76 in accordance with the adopted control value. In this case, the amount of change in the opening degree of the hot water supply three-way valve 76 can be suppressed, which has the advantage of stabilizing the temperature of the waste hot water flowing through the waste heat supply path 7.

[0070] The air conditioning control device 2 performs the operation shown in Fig. 3 at a predetermined time interval while the air conditioning system 1 is in operation. The air conditioning control device 2 may also detect the operating state of the hot water supply pump 61 at intervals shorter than the predetermined time interval, and perform interrupt control when it detects that the hot water supply pump 61 has started operating or stopped operating. In this case, the air conditioning control device 2 may start the operation shown in Fig. 3 in response to the interrupt control. The air conditioning control device 2 may also perform the operation shown in Fig. 3 from step S16 by interrupt control when it detects that the hot water supply pump 61 has started operating.

[0071] The temperature threshold value, target temperature TD, and low and high set values ​​of target value a described in relation to the above operation are stored, for example, in the storage unit 202. The PID control described above for controlling the opening of the hot water supply three-way valve 76 is one example, and the air conditioning control device 2 may control the opening of the hot water supply three-way valve 76 using a function, a table, a program, or AI (artificial intelligence).

[0072] [1-3. Effects, etc.] As described above, the air conditioning control device 2 is a control device provided in an air conditioning system 1 that includes at least an absorption chiller 10 that uses, as a heat source, waste hot water heated by waste heat from the power generation device 4, and a hot water heat exchanger 6 that heats water using the waste heat from the power generation device 4 as a heat source. The air conditioning control device 2 includes a control unit 201, which has an acquisition unit 211. The acquisition unit 211 acquires the temperature of the waste hot water supplied to the hot water heat exchanger 6 and the operating state of the hot water pump 61 that supplies water to the hot water heat exchanger 6. The control unit 201 permits the supply of waste hot water to the hot water heat exchanger 6 when the temperature of the waste hot water is higher than a temperature threshold and the hot water pump 61 is operating. The control unit 201 prohibits the supply of waste hot water to the hot water heat exchanger 6 when the temperature of the waste hot water is equal to or lower than the temperature threshold, or when the hot water pump 61 is not operating. The temperature of the waste hot water is, for example, a temperature T5 detected by a temperature sensor T5 provided in the waste heat supply path 7.

[0073] According to this, in the air conditioning system 1 that uses the waste heat of the power generation device 4 as a heat source for the absorption chiller 10 and the hot water heat exchanger 6, the use of the waste heat in the hot water heat exchanger 6 is appropriately limited. Therefore, the use of waste heat in the air conditioning system 1 can be appropriately adjusted.

[0074] The absorption chiller 10 and the hot water utilization heat exchanger 6 are connected to a waste heat supply path 7 through which waste hot water flows. The control unit 201 controls a hot water three-way valve 76 that adjusts the supply of waste hot water from the waste heat supply path 7 to the hot water utilization heat exchanger 6.

[0075] According to this configuration, in which waste hot water heated by waste heat from the power generation device 4 is supplied to the absorption chiller 10 and the hot water heat exchanger 6, the waste hot water flowing to the hot water heat exchanger 6 is adjusted by the hot water three-way valve 76. This makes it possible to appropriately limit the use of waste heat in the hot water heat exchanger 6 and appropriately adjust the use of waste heat in the air conditioning system 1.

[0076] In the air conditioning system 1, the absorption chiller 10 is connected to the waste heat supply path 7 upstream of the hot water heat exchanger 6. The acquisition unit 211 acquires the temperature of the waste hot water detected in the waste heat supply path 7 between the absorption chiller 10 and the hot water heat exchanger 6 as the temperature of the waste hot water to be supplied to the hot water heat exchanger 6. For example, the acquisition unit 211 acquires a temperature T5 detected by a temperature sensor T5 provided in the waste heat supply path 7.

[0077] According to this, the supply of waste hot water to the hot water heat exchanger 6 is adjusted based on the temperature of the waste hot water detected between the absorption chiller 10 and the hot water heat exchanger 6, thereby appropriately limiting the use of waste heat to the hot water heat exchanger 6.

[0078] In the air conditioning system 1, the absorption chiller 10 is connected to the waste heat supply path 7 upstream of the hot water heat exchanger 6. The control unit 201 is capable of setting a priority to determine whether or not to give the hot water heat exchanger 6 priority over other waste heat utilization devices when utilizing the waste heat of the power generation device 4. The control unit 201 controls the hot water three-way valve 76 in accordance with the priority setting. The other waste heat utilization device is, for example, the absorption chiller 10.

[0079] This appropriately limits the utilization of waste heat in the hot water heat exchanger 6 depending on whether the hot water heat exchanger 6 has priority in utilizing the waste heat of the power generation device 4. This allows the utilization of waste heat in the air conditioning system 1 to be appropriately adjusted.

[0080] When the priority setting is set so that the hot water heat exchanger 6 does not have priority over other waste heat utilization devices, the control unit 201 controls the hot water three-way valve 76 depending on whether the other waste heat utilization devices are in operation. For example, the control unit 201 controls the hot water three-way valve 76 depending on whether the absorption chiller 10 is in cooling operation.

[0081] This appropriately limits the utilization of waste heat in the hot water heat exchanger 6 in accordance with the utilization state of waste heat in other waste heat utilization equipment. Therefore, the utilization of waste heat in the air conditioning system 1 can be appropriately adjusted.

[0082] The control method of this embodiment is a control method for an air conditioning system 1 that includes at least an absorption chiller 10 that uses, as a heat source, waste hot water heated by waste heat from a power generation unit 4, and a hot water heat exchanger 6 that heats water using the waste heat from the power generation unit 4. In this control method, the air conditioning control device 2 acquires the temperature of the waste hot water supplied to the hot water heat exchanger 6 and the operating state of a hot water pump 61 that supplies water to the hot water heat exchanger 6. Then, when the temperature of the waste hot water is higher than a temperature threshold and the hot water pump 61 is operating, the supply of waste hot water to the hot water heat exchanger 6 is permitted. Then, when the temperature of the waste hot water is equal to or lower than the temperature threshold, or when the hot water pump 61 is not operating, the supply of waste hot water to the hot water heat exchanger 6 is prohibited. According to this, in the air conditioning system 1 that uses the waste heat of the power generation device 4 as a heat source for the absorption chiller 10 and the hot water heat exchanger 6, the use of the waste heat in the hot water heat exchanger 6 is appropriately limited. Therefore, the use of waste heat in the air conditioning system 1 can be appropriately adjusted.

[0083] (Other Embodiments) As described above, the above-mentioned embodiments have been described as examples disclosed in the present application. However, the technology in the present disclosure is not limited to these, and can be applied to embodiments in which modifications, substitutions, additions, omissions, etc. are made. Furthermore, it is also possible to combine the components described in the above-mentioned embodiments to create new embodiments. Therefore, other embodiments will be described below as examples.

[0084] In the above-described embodiment, for example, the control device that performs the processing shown in Fig. 3 may be a device separate from the air conditioning control device 2. That is, in the air conditioning system 1 that includes the air conditioning control device 2 that controls the operation of the absorption chiller 10, the processing shown in Fig. 3 may be executed by a device separate from the air conditioning control device 2.

[0085] In the above-described embodiment, an example has been described in which the power generation control device 3 that controls the operation of the power generation device 4 and the air conditioning control device 2 are configured as separate devices. For example, in the above-described embodiment, the air conditioning control device 2 may have the functions of the power generation control device 3 in the air conditioning system 1, and the power generation control device 3 may be omitted. In this case, the air conditioning control device 2 may be configured as a device that controls, for example, air conditioning using the absorption chiller 10 and the number of power generation devices 4 in operation.

[0086] In the above-described embodiment, the control unit 201 has been described as setting the target value a to a high temperature setting value when the absorption chiller 10, which is another waste heat utilization equipment, is in cooling operation. This is one example. For example, the control unit 201 may set the target value a to a high temperature setting value when the absorption chiller 10, which is another waste heat utilization equipment, is in cooling operation or heating operation. Furthermore, when the other waste heat utilization equipment is a device different from the absorption chiller 10, in step S20, the control unit 201 may determine whether the other waste heat utilization equipment is in operation.

[0087] The configuration of the absorption chiller 10 described in the above-described embodiment is an example. For example, the heat transfer tube 73A and the gas burner 20 do not need to be provided in the same location in the regenerator 15. A configuration in which a portion for heating the absorbing solution using the heat transfer tube 73A and a portion for heating the absorbing solution using the gas burner 20 are provided separately may be provided. Furthermore, the regenerator 15 may be divided into a first regenerator that heats and regenerates the absorbing solution using the heat transfer tube 73A and a second regenerator that heats and regenerates the absorbing solution using the gas burner 20. The absorption chiller 10 may be a double-effect refrigeration device having a low-temperature regenerator and a high-temperature regenerator. In the above-described embodiment, the gas burner 20 has been described as the second heat source of the regenerator 15. However, the absorption chiller 10 may be configured to include a heat source other than the gas burner 20.

[0088] The operation of the air conditioning control device 2 in the above-described embodiment can be realized as a program executed by a processor. This program can also be realized in a form stored in a non-transitory computer-readable storage medium. Alternatively, this program can be stored in a server device or the like, and the air conditioning control device 2 can download the program from the server device to realize the above-described operation. The processor of the control unit 201 may be configured with a single processor or multiple processors. The processor of the control unit 201 may also be hardware programmed to realize the corresponding functional units. The processor of the control unit 201 may be configured with, for example, an ASIC (Application Specific Integrated Circuit) or FPGA (Field Programmable Gate Array).

[0089] The configuration of the air conditioning control device 2 shown in Figure 1 is one example, and the specific implementation form is not particularly limited. In other words, it is not necessarily necessary to implement hardware corresponding to each unit individually, and it is also possible to configure the system so that a single processor executes a program to realize the functions of each unit. Furthermore, some of the functions realized by software in the above-mentioned embodiment may be implemented by hardware, or some of the functions realized by hardware may be implemented by software.

[0090] The step units of the operation shown in Figure 3 are divided according to the main processing content to make the operation easier to understand, and the operation is not limited by the way the processing units are divided or the names of the processing units. The operation may be divided into more step units depending on the processing content. Furthermore, one step unit may be divided so that it includes more processing. Furthermore, the order of the steps may be changed as appropriate within the scope of the present disclosure.

[0091] It should be noted that the above-described embodiments are intended to illustrate the technology of the present disclosure, and various modifications, substitutions, additions, omissions, etc. may be made within the scope of the claims or their equivalents.

[0092] (Additional Notes) The above description of the embodiments discloses the following techniques.

[0093] (Technology 1) A control device provided in an air conditioning system including at least an absorption chiller that uses waste hot water heated by waste heat from a power generation unit as a heat source and a hot water heat exchanger that heats water using the waste hot water as a heat source, the control device comprising: an acquisition unit that acquires the temperature of the waste hot water supplied to the hot water heat exchanger and the operating state of a hot water pump that supplies the water to the hot water heat exchanger; and a control unit, the control unit permitting the supply of the waste hot water to the hot water heat exchanger when the temperature of the waste hot water is higher than a temperature threshold and the hot water pump is operating, and prohibiting the supply of the waste hot water to the hot water heat exchanger when the temperature of the waste hot water is equal to or lower than the temperature threshold or when the hot water pump is not operating. This appropriately limits the use of waste heat to the hot water heat exchanger in an air conditioning system that uses waste heat from a power generation unit as a heat source for the absorption chiller and the hot water heat exchanger, thereby enabling appropriate adjustment of the use of waste heat in the air conditioning system.

[0094] (Technology 2) The control device according to Technology 1, wherein the absorption chiller and the hot water heat exchanger are connected to a waste heat supply path through which the waste hot water flows, and the control unit controls a valve that adjusts the supply of the waste hot water from the waste heat supply path to the hot water heat exchanger. In this configuration, in which waste hot water heated by waste heat from a power generation device is supplied to the absorption chiller and the hot water heat exchanger, the supply of waste hot water flowing to the hot water heat exchanger is adjusted. This makes it possible to appropriately limit the use of waste heat in the hot water heat exchanger and appropriately adjust the use of waste heat in the air conditioning system.

[0095] (Technology 3) The control device according to Technology 2, wherein the absorption chiller is connected to the waste heat supply path upstream of the hot water heat exchanger, and the acquisition unit acquires the temperature of the waste hot water detected in the waste heat supply path between the absorption chiller and the hot water heat exchanger as the temperature of the waste hot water to be supplied to the hot water heat exchanger. With this, the supply of waste heat to the hot water heat exchanger is adjusted based on the temperature of the waste hot water detected between the absorption chiller and the hot water heat exchanger, thereby making it possible to appropriately limit the use of waste heat to the hot water heat exchanger.

[0096] (Technology 4) The control device according to Technology 2 or Technology 3, wherein the absorption chiller is connected to the waste heat supply path upstream of the hot water heat exchanger, and the control unit is capable of setting a priority for whether to give the hot water heat exchanger priority over other waste heat utilization devices in utilizing the waste heat of the power generation system, and controls the valve according to the priority setting. This appropriately limits the utilization of waste heat in the hot water heat exchanger depending on whether the hot water heat exchanger is given priority in utilizing the waste heat of the power generation system, thereby making it possible to appropriately adjust the utilization of waste heat in the air conditioning system.

[0097] (Technology 5) The control device according to Technology 4, wherein when the priority setting is set so that the hot water heat exchanger is not given priority over the other waste heat utilization devices, the control unit controls the valve depending on whether the other waste heat utilization devices are in operation. This appropriately limits the use of waste heat in the hot water heat exchanger depending on the waste heat utilization status of the other waste heat utilization devices. This allows appropriate adjustment of the use of waste heat in the air conditioning system.

[0098] (Technology 6) A control method for an air conditioning system including at least an absorption chiller that uses waste hot water heated by waste heat from a power generation unit as a heat source and a hot water heat exchanger that heats water using the waste heat from the power generation unit as a heat source, the control method comprising: a control device that acquires the temperature of the waste hot water supplied to the hot water heat exchanger and the operating state of a hot water pump that supplies the water to the hot water heat exchanger; permitting the supply of the waste hot water to the hot water heat exchanger when the temperature of the waste hot water is higher than a temperature threshold and the hot water pump is operating; and prohibiting the supply of the waste hot water to the hot water heat exchanger when the temperature of the waste hot water is equal to or lower than the temperature threshold or when the hot water pump is not operating. This method appropriately limits the use of waste heat in the hot water heat exchanger in an air conditioning system that uses waste heat from a power generation unit as a heat source for the absorption chiller and the hot water heat exchanger, thereby appropriately adjusting the use of waste heat in the air conditioning system.

[0099] As described above, the control device and the control method for an absorption chiller according to the present invention can be used to control an air conditioning system that uses waste heat from a power generation plant as a heat source for an absorption chiller and hot water supply.

[0100] 1 Air conditioning system 1A, 1B, 1C Communication line 2 Air conditioning control device (control device) 3 Power generation control device 4 Power generation device 5 Heating use heat exchanger 5A Hot water pipe 6 Hot water use heat exchanger 6A Hot water pipe 7 Waste heat supply path 10 Absorption chiller 11 Evaporator 11A Liquid reservoir 12 Absorber 12A Dilute absorbent reservoir 13 Evaporator-absorber shell 15 Regenerator 15A Absorbent reservoir 16 Condenser 17 Indoor unit 18 Cooler 20 Gas burner 21 Concentrated absorbent pipe 22 Dilute absorbent pipe 23, 24, 25 Refrigerant pipe 26 Cooling water pipe 27 Cold water pipe 27A Heat transfer pipe 31 Dilute absorbent pump 32 Refrigerant pump 33 Concentrated absorbent pump 35 Cooling water pump 37 Opening / closing valve 41 Generator 42 Engine 43 Radiator 51, 71 Pump 61 Hot water supply pump 72 Heating three-way valve 74 Three-way valve 76 Hot water supply three-way valve (valve) 73 Hot water supply pipe 73A Heat transfer pipe 201 Control unit 202 Memory unit 211 Acquisition unit 212 Processing unit 221 Communication unit 222 Input unit T131 Inlet water temperature T142 Outlet water temperature

Claims

1. A control device provided in an air conditioning system including at least an absorption chiller that uses waste hot water heated by waste heat from a power generation device as a heat source, and a hot water heat exchanger that heats water using the waste hot water as a heat source, and comprising: an acquisition unit that acquires the temperature of the waste hot water supplied to the hot water heat exchanger and the operating state of a hot water pump that supplies the water to the hot water heat exchanger; and a control unit, wherein the control unit permits the supply of the waste hot water to the hot water heat exchanger when the temperature of the waste hot water is higher than a temperature threshold and the hot water pump is operating, and prohibits the supply of the waste hot water to the hot water heat exchanger when the temperature of the waste hot water is equal to or lower than the temperature threshold or when the hot water pump is not operating.

2. The control device according to claim 1, wherein the absorption chiller and the hot water heat exchanger are connected to a waste heat supply path through which the waste hot water flows, and the control unit controls a valve that adjusts the supply of the waste hot water from the waste heat supply path to the hot water heat exchanger.

3. The control device described in claim 2, wherein the absorption chiller is connected to the waste heat supply path upstream of the hot water heat exchanger, and the acquisition unit acquires the temperature of the waste hot water detected in the waste heat supply path between the absorption chiller and the hot water heat exchanger as the temperature of the waste hot water supplied to the hot water heat exchanger.

4. The control device according to claim 2, wherein the absorption chiller is connected to the waste heat supply path upstream of the hot water heat exchanger, and the control unit is capable of setting a priority as to whether or not to give the hot water heat exchanger priority over other waste heat utilization equipment in utilizing the waste heat of the power generation device, and controls the valve in accordance with the priority setting.

5. The control device according to claim 4, wherein when the priority setting is set so that the hot water heat exchanger is not given priority over the other waste heat utilization equipment, the control unit controls the valve depending on whether the other waste heat utilization equipment is in operation or not.

6. A control method for an air conditioning system including at least an absorption chiller that uses waste hot water heated by waste heat from a power generation device as a heat source, and a hot water heat exchanger that heats water using the waste hot water as a heat source, wherein a control device acquires the temperature of the waste hot water supplied to the hot water heat exchanger and the operating state of a hot water pump that supplies the water to the hot water heat exchanger, permits the supply of the waste hot water to the hot water heat exchanger when the temperature of the waste hot water is higher than a temperature threshold and the hot water pump is operating, and prohibits the supply of the waste hot water to the hot water heat exchanger when the temperature of the waste hot water is equal to or lower than the temperature threshold or when the hot water pump is not operating.

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