Heat recovery system

Abstract

To enhance the utilization efficiency of heat generated in a heat source.SOLUTION: A heat recovery system 20 comprises: a heat source side heat exchanger 32 for exchanging heat between exhaust heat generated in a heat source facility 10, and a heat medium; a heat storage tank 50 connected to the heat source side heat exchanger 32 via a first circulation pipe 40, and storing the heat medium supplied from the heat source side heat exchanger 32; a first pump 42 provided in the first circulation pipe 40, and circulating the heat medium between the heat source side heat exchanger 32 and the heat storage tank 50; a heat pump 62 connected to the heat storage tank 50 via a second circulation pipe 70, and utilizing heat supplied from the heat storage tank 50; and a second pump 72 provided in the second circulation pipe 70, and circulating the heat medium between the heat storage tank 50 and the heat pump 62.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a heat recovery system. [Background technology]

[0002] A heat recovery system is known that includes a heat source-side heat exchanger that exchanges heat, such as exhaust heat generated in a heat source such as equipment, with a heat medium; a user-side heat exchanger such as a heat pump that is connected to the heat source-side heat exchanger via a circulation pipe and uses the heat of the heat medium supplied from the heat source-side heat exchanger; and a pump that is provided in the circulation pipe and circulates the heat medium between the heat source-side heat exchanger and the user-side heat exchanger (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2023-002339 Summary of the Invention [Problem to be solved by the invention]

[0004] In the heat recovery system disclosed in Patent Document 1, heat from a heat source recovered by a heat source-side heat exchanger is supplied to a user-side heat exchanger via a heat medium. Therefore, if the heat source does not generate heat such as waste heat, the user-side heat exchanger, such as a heat pump, may not be able to operate. On the other hand, even if the heat source generates heat, if there is no heat demand for the user-side heat exchanger, such as a heat pump, the heat from the heat source may not be able to be used.

[0005] As described above, the heat recovery system disclosed in Patent Document 1 has room for improvement in the efficiency of using the heat generated in the heat source.

[0006] In consideration of the above, an object of the present invention is to improve the utilization efficiency of heat generated in a heat source. [Means for solving the problem]

[0007] The heat recovery system described in claim 1 includes a heat source side heat exchanger that exchanges heat generated in a heat source with a heat medium, a heat storage tank that is connected to the heat source side heat exchanger via a first circulation piping and that stores the heat medium supplied from the heat source side heat exchanger, a first pump that is provided on the first circulation piping and that circulates the heat medium between the heat source side heat exchanger and the heat storage tank, a user side heat exchanger that is connected to the heat storage tank via a second circulation piping and that utilizes the heat supplied from the heat storage tank, and a second pump that is provided on the second circulation piping and that circulates the heat medium between the heat storage tank and the user side heat exchanger.

[0008] According to the heat recovery system of claim 1, the heat source-side heat exchanger exchanges heat between the heat generated in the heat source and the heat medium. The heat generated in the heat source is recovered by the heat source-side heat exchanger via the heat medium.

[0009] The heat source-side heat exchanger is connected to a heat storage tank via a first circulation pipe. The heat storage tank stores the heat medium supplied from the heat source-side heat exchanger. The first circulation pipe is provided with a first pump.

[0010] The first pump circulates a heat medium between the heat source-side heat exchanger and the heat storage tank. By operating the first pump, heat from the heat source recovered by the heat source-side heat exchanger is supplied to the heat storage tank via the heat medium and stored in the heat storage tank.

[0011] Therefore, in the present invention, even when there is no heat demand for the utilization-side heat exchanger, the heat generated in the heat source can be recovered and stored.

[0012] A user-side heat exchanger is connected to the heat storage tank via a second circulation pipe. The user-side heat exchanger utilizes the heat of the heat medium supplied from the heat storage tank. A second pump is provided on the second circulation pipe. The second pump circulates the heat medium between the heat storage tank and the user-side heat exchanger. By operating this second pump, the heat medium stored in the heat storage tank is supplied to the user-side heat exchanger via the heat medium and used in the user-side heat exchanger.

[0013] Therefore, for example, even when the heat source does not generate heat, the heat stored in the heat storage tank can be supplied to the utilization-side heat exchanger.

[0014] In this way, the present invention can improve the utilization efficiency of the heat generated by the heat source.

[0015] The heat recovery system according to claim 2 is the heat recovery system according to claim 1, further comprising a heat storage amount adjusting unit that adjusts the amount of heat stored in the heat storage tank.

[0016] According to the heat recovery system of claim 2, a heat storage amount adjusting unit that adjusts the amount of heat stored in the heat storage tank is provided, and the amount of heat stored in the heat storage tank can be maintained at a predetermined value by this heat storage amount adjusting unit.

[0017] As a result, in the present invention, even when the heat source does not generate heat, for example, a heat medium at a predetermined temperature can be supplied from the heat storage tank to the user-side heat exchanger, thereby improving the convenience of the user-side heat exchanger.

[0018] A heat recovery system according to a third aspect of the present invention is the heat recovery system according to the first or second aspect, wherein the heat storage tank has a latent heat storage material that exchanges heat with a heat medium.

[0019] According to the heat recovery system of claim 3, the heat storage tank has a latent heat storage material that exchanges heat with the heat medium. The latent heat storage material stores and releases heat without any temperature change, so it is possible to suppress sudden temperature changes in the heat storage tank. Therefore, it is possible to stably supply a heat medium within a predetermined temperature range from the heat storage tank to the user-side heat exchanger. Furthermore, compared to sensible heat storage materials, latent heat storage materials store a larger amount of heat per unit volume. Therefore, it is possible to increase the heat storage efficiency of the heat generated by the heat source while suppressing an increase in the size of the heat storage tank. [Effects of the Invention]

[0020] As described above, according to the present invention, it is possible to improve the utilization efficiency of the heat generated in the heat source. [Brief explanation of the drawings]

[0021] [Figure 1] 1 is a circuit diagram illustrating a heat recovery system according to an embodiment. [Figure 2] FIG. 2 is a vertical cross-sectional view showing the heat storage tank shown in FIG. [Figure 3] FIG. 2 is a partial vertical cross-sectional view showing the heat storage tank shown in FIG. [Figure 4] FIG. 2 is a hardware configuration diagram of a control device according to an embodiment. [Figure 5] FIG. 1 is a system relationship diagram of a heat recovery system according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0022] Hereinafter, an embodiment will be described with reference to the drawings.

[0023] (Heat recovery system) 1 shows a heat recovery system 20 according to this embodiment. As an example, the heat recovery system 20 is an exhaust heat recovery system (exhaust heat reuse system) that uses a heat pump 62 to raise the temperature of exhaust heat (waste heat) recovered from heat source equipment 10, such as production equipment in the manufacturing industry, and supplies the heat to utilization equipment 16. The heat recovery system 20 includes a heat recovery section (heat recovery system) 30, a heat utilization section (heat utilization system) 60, and a heat storage amount adjustment section 80.

[0024] The heat source equipment 10 is an example of a heat source.

[0025] (Heat recovery section) The heat recovery unit 30 includes a heat source side heat exchanger 32, a first circulation pipe 40, a first pump 42, a first temperature sensor 44, a flow rate control valve 46, and a heat storage tank 50. The heat recovery unit 30 forms a heat storage cycle in which exhaust heat is recovered from the heat source equipment 10 and stored in the heat storage tank 50.

[0026] (Heat source side heat exchanger) The heat source side heat exchanger 32 is a heat exchanger for recovering exhaust heat generated in the heat source equipment 10. The heat source side heat exchanger 32 is connected to the heat source equipment 10 via the exhaust heat supply piping 12. As a result, exhaust heat from exhaust gas, exhaust hot water, etc. generated in the heat source equipment 10 is supplied to the heat source side heat exchanger 32 via the exhaust heat supply piping 12.

[0027] In addition, the heat source side heat exchanger 32 is connected to the exhaust heat discharge pipe 14. As a result, the exhaust heat supplied from the heat source equipment 10 to the heat source side heat exchanger 32 is discharged to the outside via the exhaust heat discharge pipe 14.

[0028] (First circulation piping) The heat source side heat exchanger 32 is connected to the heat storage tank 50 via a first circulation pipe 40. The first circulation pipe 40 is an annular pipe that circulates a heat medium between the heat source side heat exchanger 32 and the heat storage tank 50.

[0029] The first circulation piping 40 has a feed piping 40A that supplies the heat medium from the lower part of the heat storage tank 50 to the heat source side heat exchanger 32, and a return piping 40B that returns the heat medium from the heat source side heat exchanger 32 to the upper part of the heat storage tank 50. In addition, the first circulation piping 40 is provided with a first pump 42, a first temperature sensor 44, and a flow rate adjustment valve 46.

[0030] The heat medium is, for example, water or oil.

[0031] (First pump) The first pump 42 is a circulation pump that circulates the heat medium between the heat source side heat exchanger 32 and the heat storage tank 50 by pressurizing the heat medium in the first circulation piping 40 in a predetermined direction (the direction of arrow a).

[0032] As an example, the first pump 42 is provided in the feed pipe 40A of the first circulation pipe 40. That is, the first pump 42 is provided in the first circulation pipe 40 downstream of the heat storage tank 50 and upstream of the heat source-side heat exchanger 32. As a result, in this embodiment, compared to when the first pump 42 is provided in the return pipe 40B of the first circulation pipe 40, the relatively low-temperature heat medium stored in the lower part of the heat storage tank 50 can be supplied to the heat source-side heat exchanger 32 more efficiently.

[0033] The first pump 42 is controlled by a control device 100, which will be described later. The control device 100 operates the first pump 42 when exhaust heat is supplied from the heat source equipment 10 to the heat source side heat exchanger 32 via the exhaust heat supply piping 12. As a result, in the heat source side heat exchanger 32, heat is exchanged between the exhaust heat supplied from the heat source equipment 10 and the heat medium supplied from the first circulation piping 40. As a result, the heat medium is warmed (heated) by the exhaust heat, and the exhaust heat is recovered into the heat medium.

[0034] The first pump 42 is not limited to being provided in the feed pipe 40A of the first circulation pipe 40, but may be provided in the return pipe 40B of the first circulation pipe 40, for example.

[0035] (heat storage tank) The heat storage tank 50 stores the exhaust heat by storing the heat medium supplied from the heat source side heat exchanger 32 via the first circulation piping 40. The heat storage tank 50 is, for example, a sealed tank.

[0036] The heat storage tank 50 is not limited to a sealed tank, and may be another type of tank.

[0037] 2, the heat storage tank 50 is filled with a heat medium and is under pressure. A feed pipe 40A of the first circulation pipe 40 is connected to the bottom of the heat storage tank 50, and a return pipe 40B of the first circulation pipe 40 is connected to the top of the heat storage tank 50. This causes temperature stratification inside the heat storage tank 50.

[0038] Furthermore, a plurality of heat storage temperature sensors 52 are provided inside the heat storage tank 50. The plurality of heat storage temperature sensors 52 are temperature sensors that detect the temperature of the heat medium inside the heat storage tank 50 and output the detected heat medium temperature to the control device 100, which will be described later.

[0039] The plurality of heat storage temperature sensors 52 are arranged at predetermined intervals in the height direction of the heat storage tank 50. By detecting the temperature of the heat medium stored in the heat storage tank 50 using these heat storage temperature sensors 52, it is possible to estimate the temperature distribution in the height direction within the heat storage tank 50, i.e., the amount of heat stored in the heat storage tank 50.

[0040] 3, the heat storage tank 50 has a plurality of latent heat storage material modules 54. The plurality of latent heat storage material modules 54 are modularized by, for example, sealing the latent heat storage material in a bag-shaped container (pack).

[0041] A plurality of latent heat storage material modules (latent heat storage material packs) 54 are provided in the heat storage tank 50 and are capable of exchanging heat with the heat medium stored in the heat storage tank 50. The latent heat storage material of the latent heat storage material modules 54 changes phase in association with heat exchange with the heat medium, thereby storing the heat of the heat medium.

[0042] Here, the latent heat storage material of the latent heat storage material module 54 has a larger heat storage capacity per unit volume than a sensible heat storage material. Therefore, by providing a plurality of latent heat storage material modules 54 in the heat storage tank 50, the heat storage efficiency of the heat storage tank 50 is improved.

[0043] Furthermore, the latent heat storage material module 54 is made of a latent heat storage material having a predetermined melting point so that a heat medium at a predetermined temperature is supplied from the heat storage tank 50 to the heat pump 62, which will be described later. Specifically, the latent heat storage material is selected so that its melting point is within the required temperature range of the heat pump 62.

[0044] As the latent heat storage material, for example, paraffin-based, fatty acid-based, sugar alcohol-based, inorganic hydrate-based, inorganic salt aqueous solution-based, TBAB-based, etc. may be used.

[0045] (First temperature sensor) 1, the first temperature sensor 44 is a sensor that detects the temperature of the heat medium flowing inside the first circulation piping 40. The first temperature sensor 44 is provided in the return piping 40B of the first circulation piping 40, for example.

[0046] More specifically, the first temperature sensor 44 is provided in the return pipe 40B downstream of the flow rate adjustment valve 46. This first temperature sensor 44 detects the temperature of the heat medium flowing through the return pipe 40B, and outputs the detected temperature of the heat medium to the control device 100, which will be described later.

[0047] (Flow control valve) The flow rate control valve 46 is a valve that adjusts the flow rate of the heat medium flowing through the first circulation pipe 40. In addition, the flow rate control valve 46 is, for example, provided in the return pipe 40B of the first circulation pipe 40. The flow rate control valve 46 is controlled by the control device 100, which will be described later.

[0048] The control device 100 increases or decreases the opening of the flow control valve 46 based on the temperature of the heat medium detected by the first temperature sensor 44 so that the temperature of the heat medium supplied from the heat source side heat exchanger 32 to the heat storage tank 50 becomes a predetermined temperature, thereby adjusting the flow rate of the heat medium supplied from the heat source side heat exchanger 32 to the heat storage tank 50.

[0049] The first temperature sensor 44 and the flow rate adjusting valve 46 may be provided as needed, and may be omitted as appropriate.

[0050] (Heat Utilization Department) The heat utilization section 60 includes a heat storage tank 50, a heat pump 62, a second circulation pipe 70, a second pump 72, a second temperature sensor 74, a bypass pipe 76, and a three-way valve 78. The heat utilization section 60 forms a waste heat utilization cycle that heats the waste heat stored in the heat storage tank 50 in response to a request from the utilization equipment 16 and supplies the waste heat to the utilization equipment 16. The heat utilization section 60 and the heat recovery section 30 share the heat storage tank.

[0051] (Second circulation piping) The heat pump 62 is connected to the heat storage tank 50 via a second circulation pipe 70. The second circulation pipe 70 is an annular pipe that circulates a heat medium between the heat storage tank 50 and the heat pump 62.

[0052] The second circulation piping 70 has a feed piping 70A that supplies the heat medium from the upper part of the heat storage tank 50 to the heat pump 62, and a return piping 70B that returns the heat medium from the heat pump 62 to the lower part of the heat storage tank 50. In addition, the second circulation piping 70 is provided with a second pump 72, a second temperature sensor 74, and a bypass piping 76.

[0053] (Second pump) The second pump 72 is a circulation pump that circulates the heat medium between the heat storage tank 50 and the heat pump 62 by pressurizing and pumping the heat medium in the second circulation piping 70 in a predetermined direction (the direction of arrow b). The second pump 72 is provided on the return piping 70B of the second circulation piping 70. That is, the second pump 72 is provided on the second circulation piping 70 downstream of the heat pump 62 and upstream of the heat storage tank 50. As a result, in this embodiment, compared to when the second pump 72 is provided on the feed piping 70A of the second circulation piping 70, the heat medium used by the heat pump 62 and whose temperature has been reduced can be stored in the lower part of the heat storage tank 50 where the relatively low-temperature heat medium is stored.

[0054] The second pump 72 is controlled by a control device 100, which will be described later. When a heat request is received from the utilization facility 16, the control device 100 operates the second pump 72 and the heat pump 62. As a result, a heat medium at a predetermined temperature is supplied from the heat storage tank 50 to the heat pump 62, which will be described later.

[0055] The second pump 72 may be provided not only in the return pipe 70B of the second circulation pipe 70 but also in the feed pipe 70A of the second circulation pipe 70.

[0056] (heat pump) The heat pump 62 is a heat supplier that generates hot water (high-temperature water) to be supplied to the utilization facility 16, for example, by pumping up heat from a heat medium supplied from the heat storage tank 50 via the second circulation piping 70.

[0057] The heat pump 62 includes a low-temperature heat exchanger (heat absorption heat exchanger), a compressor, a high-temperature heat exchanger (heat release heat exchanger), an expander, and a circulation pipe for circulating a heat medium among the low-temperature heat exchanger, the compressor, the high-temperature heat exchanger, and the expander (not shown). The low-temperature heat exchanger is an example of a utilization-side heat exchanger.

[0058] The low-temperature side heat exchanger heats the heat medium supplied from the second circulation piping 70 (feed piping 70A) by exchanging heat between the heat medium and the heat medium flowing through the circulation piping of the heat pump 62. The compressor compresses the heat medium supplied from the low-temperature side heat exchanger to increase the temperature of the heat medium.

[0059] The high-temperature side heat exchanger generates hot water by, for example, exchanging heat between the heat medium supplied from the compressor and water to be supplied to the utilization facility 16. The expander expands the heat medium supplied from the high-temperature side heat exchanger to lower the temperature of the heat medium. The lowered temperature heat medium is supplied to the low-temperature side heat exchanger and reheated there.

[0060] The heat pump 62 generates hot water (high-temperature water) in the high-temperature side heat exchanger by repeating the above cycle. The hot water generated in the high-temperature side heat exchanger is supplied to the utilization facility 16 via the supply pipe 18.

[0061] The heat pump 62 is not limited to a hot water heat pump that generates hot water, but may be a heat pump (industrial heat pump) such as a steam heat pump that generates steam or a hot air heat pump that generates hot air.

[0062] (Second temperature sensor) The second temperature sensor 74 is a sensor that detects the temperature of the heat medium flowing through the second circulation pipe 70. The second temperature sensor 74 is provided in the feed pipe 70A of the second circulation pipe 70, for example.

[0063] More specifically, the second temperature sensor 74 is provided on the feed pipe 70A downstream of the connection portion with the bypass pipe 76. This second temperature sensor 74 detects the temperature of the heat medium flowing through the feed pipe 70A, and outputs the detected temperature of the heat medium to the control device 100, which will be described later.

[0064] (Bypass piping) The second circulation piping 70 is provided with a bypass piping 76 that bypasses the heat storage tank 50. The bypass piping 76 connects the return piping 70B and the feed piping 70A of the second circulation piping 70. In other words, the bypass piping 76 connects the downstream side and upstream side of the second circulation piping 70 with respect to the heat pump 62. The bypass piping 76 and a portion of the second circulation piping 70 form a temperature-lowering circulation flow path that bypasses the heat storage tank 50.

[0065] The temperature-lowering circulation flow path is provided with a second pump 72 and a second temperature sensor 74. A three-way valve 78 is provided at the connection between the bypass pipe 76 and the return pipe 70B of the second circulation pipe 70.

[0066] (three-way valve) The three-way valve 78 branches the bypass pipe 76 from the return pipe 70B of the second circulation pipe 70, and serves as a branch flow rate adjustment valve that adjusts the flow rate of the heat medium flowing through the return pipe 70B and the bypass pipe 76.

[0067] The three-way valve 78 is configured to be able to open and close the return pipe 70B of the second circulation pipe 70 and the bypass pipe 76. By opening the return pipe 70B and closing the bypass pipe 76 with this three-way valve 78, the heat medium is returned from the heat pump 62 to the heat storage tank 50 via the return pipe 70B.

[0068] Meanwhile, the three-way valve 78 closes the return pipe 70B of the second circulation pipe 70 and opens the bypass pipe 76, causing the heat medium to bypass the heat storage tank 50. In other words, the heat medium that has passed through the heat pump 62 and whose temperature has been reduced is supplied again to the heat pump 62 via the bypass pipe 76. This three-way valve 78 is controlled by the control device 100, which will be described later.

[0069] The three-way valve 78 is configured to be able to open and close the return pipe 70B of the second circulation pipe 70 and the bypass pipe 76. As a result, the heat medium supplied to the three-way valve 78 from the heat pump 62 via the return pipe 70B of the second circulation pipe 70 is divided into the heat storage tank 50 side and the bypass pipe 76 side, and the division ratio can be set (adjusted) as desired.

[0070] Furthermore, the second temperature sensor 74, the bypass pipe 76, and the three-way valve 78 may be provided as needed, and may be omitted as appropriate.

[0071] (Heat storage amount adjustment part) The heat storage amount adjustment unit 80 includes a heat storage tank 50, a heat storage temperature sensor 52, a heating heat exchanger 82, an auxiliary heat source 84, a third circulation pipe 90, and a third pump 92. The heat storage amount adjustment unit 80 circulates the heat medium between the heat storage tank 50 and the heating heat exchanger 82, thereby forming a temperature adjustment (heating) cycle that adjusts (heats) the temperature of the heat medium stored in the heat storage tank 50 to a predetermined temperature.

[0072] (heat exchanger for heating) The heating heat exchanger 82 is a heater that heats the heat medium stored in the heat storage tank 50. The heating heat exchanger 82 is connected to the heat storage tank 50 via a third circulation piping 90, which will be described later, and heats the heat medium by exchanging heat between the heat medium flowing through the third circulation piping 90 and the auxiliary heat source 84.

[0073] (auxiliary heat source) The auxiliary heat source 84 is, for example, a heater or a boiler, and heats the heat medium flowing through the heating heat exchanger 82. This auxiliary heat source 84 is controlled by a control device 100, which will be described later. Note that the auxiliary heat source 84 is not limited to a heater or a boiler, and may be, for example, hot water or steam exhausted from the heat source equipment 10, or a heat pump.

[0074] (Third circulation piping) The third circulation piping 90 is annular piping that circulates the heat medium between the heating heat exchanger 82 and the heat storage tank 50. The third circulation piping 90 has a feed piping 90A that supplies the heat medium from the lower part of the heat storage tank 50 to the heating heat exchanger 82, and a return piping 90B that returns the heat medium from the heating heat exchanger 82 to the upper part of the heat storage tank 50. In addition, a third pump 92 is provided in the third circulation piping 90.

[0075] (Third pump) The third pump 92 is a circulation pump that circulates the heat medium between the heating heat exchanger 82 and the heat storage tank 50 by pressurizing and feeding the heat medium in the third circulation piping 90 in a predetermined direction (the direction of arrow c). As an example, the third pump 92 is provided in the feed piping 90A of the third circulation piping 90. In other words, the third pump 92 is provided in the third circulation piping 90 upstream of the heating heat exchanger 82 and downstream of the heat storage tank 50.

[0076] The third pump 92 is controlled by a control device 100, which will be described later. When the amount of heat stored in the heat storage tank 50, detected by the heat storage temperature sensor 52, is less than a predetermined value, the control device 100 activates the auxiliary heat source 84 and the third pump 92. As a result, low-temperature heat medium is supplied from the heat storage tank 50 to the heating heat exchanger 82, and the heat medium supplied to the heating heat exchanger 82 is heated by the auxiliary heat source 84.

[0077] (Control device) As shown in Fig. 4, the control device 100 controls the overall operation of the heat recovery system 20 (see Fig. 1). The control device 100 is configured by, for example, a PLC (Programmable Logic Controller).

[0078] The control device 100 includes a CPU (Central Processing Unit) 102, a memory 104 as a temporary storage area, and a non-volatile storage unit 106. The control device 100 also includes an input / output device 108. The CPU 102, memory 104, storage unit 106, and input / output device 108 are connected to one another via a bus 109. The CPU 102 is an example of a control unit.

[0079] The storage unit 106 is realized by, for example, a hard disk drive (HDD), a solid state drive (SSD), a flash memory, etc. A control program for controlling the operation of the heat recovery system 20 is stored in advance in the storage unit 106 as a recording medium.

[0080] The CPU 102 reads out the control program from the storage unit 106, loads it into the memory 104, and sequentially executes each step of the heat medium temperature control program.

[0081] 5, the control device 100 is electrically connected to the first pump 42, first temperature sensor 44, and flow rate adjustment valve 46 that constitute the heat recovery unit 30. The control device 100 is also electrically connected to the heat pump 62, second pump 72, second temperature sensor 74, and three-way valve 78 that constitute the heat utilization unit 60. The control device 100 is also electrically connected to the plurality of heat storage temperature sensors 52, auxiliary heat source 84, and third pump 92 that constitute the heat storage amount adjustment unit 80.

[0082] (Control method of heat recovery system) Next, an example of a method for controlling the heat recovery system 20 will be described while explaining the operation of the control device 100.

[0083] (Heat recovery section) First, we will explain the operation of the heat recovery unit 30. As shown in Fig. 1, when exhaust heat is supplied from the heat source equipment 10 to the heat source-side heat exchanger 32 via the exhaust heat supply piping 12, the CPU 102 (see Fig. 4) operates the first pump 42 of the heat recovery unit 30. As a result, the first pump 42 pressure-feeds the heat medium in the first circulation piping 40 in a predetermined direction (the direction of arrow a), and the heat medium circulates between the heat source-side heat exchanger 32 and the heat storage tank 50.

[0084] Specifically, a low-temperature heat medium is supplied from the bottom of the heat storage tank 50 to the heat source-side heat exchanger 32 via the feed piping 40A. The heat source-side heat exchanger 32 exchanges heat between the heat medium supplied from the heat storage tank 50 and the exhaust heat supplied from the heat source equipment 10 via the exhaust heat supply piping 12. As a result, the heat medium is heated (heated) by the exhaust heat. The heat medium heated in the heat source-side heat exchanger 32 is supplied to the top of the heat storage tank 50 via the return piping 40B of the first circulation piping 40, and is stored (heat-stored) in the heat storage tank 50.

[0085] At this time, the CPU 102 controls the flow rate adjustment valve 46 based on the temperature of the heat medium detected by the first temperature sensor 44 so that the heat medium at a predetermined temperature is supplied from the heat source side heat exchanger 32 to the heat storage tank 50.

[0086] Specifically, the opening of the flow rate control valve 46 is increased or decreased based on the temperature of the heat medium detected by the first temperature sensor 44, and the flow rate of the heat medium supplied from the heat source side heat exchanger 32 to the heat storage tank 50 is adjusted. In this way, the heat medium at a predetermined temperature is supplied to the heat storage tank 50.

[0087] (Heat Utilization Department) Next, a description will be given of the operation of the heat utilization section 60. In the initial state of the heat utilization section 60, the three-way valve 78 opens the return pipe 70B of the second circulation pipe 70 and closes the bypass pipe 76.

[0088] The CPU 102 operates the heat pump 62 and the second pump 72 in response to the supply from the utilization facility 16. As a result, the second pump 72 pressure-feeds the heat medium in the second circulation pipe 70 in a predetermined direction (the direction of arrow b), and the heat medium circulates between the heat storage tank 50 and the heat pump 62.

[0089] Specifically, a high-temperature heat transfer medium is supplied to the heat pump 62 from the top of the heat storage tank 50 via a feed pipe 70A. The heat pump 62 generates hot water (high-temperature water) etc. by pumping heat from the heat transfer medium supplied from the heat storage tank 50, and supplies it to the utilization facility 16. The heat transfer medium, whose temperature has been reduced after passing through the heat pump 62, is returned to the heat storage tank 50 via a return pipe 70B.

[0090] At this time, the CPU 102 controls the three-way valve 78 based on the temperature of the heat medium detected by the second temperature sensor 74 so that the heat medium at a predetermined temperature is supplied from the heat storage tank 50 to the heat pump 62 .

[0091] Specifically, when the temperature of the heat medium detected by the second temperature sensor 74 is equal to or higher than a predetermined temperature, the CPU 102 activates the three-way valve 78 to close the return pipe 70B and open the bypass pipe 76. As a result, the heat medium whose temperature has dropped after passing through the heat pump 62 is supplied again to the heat pump 62 via the bypass pipe 76. As a result, the temperature of the heat medium supplied to the heat pump 62 is adjusted to a predetermined temperature.

[0092] Furthermore, when the temperature of the heat medium detected by the second temperature sensor 74 is lower than a predetermined temperature, the CPU 102 actuates the three-way valve 78 to open the return pipe 70B and close the bypass pipe 76. As a result, the heat medium, whose temperature has dropped after passing through the heat pump 62, is returned to the bottom of the heat storage tank 50 via the return pipe 70B. Furthermore, the heat medium at a predetermined temperature is supplied from the top of the heat storage tank 50 to the heat pump 62 via the feed pipe 70A.

[0093] (Heat storage amount adjustment part) Next, the operation of the heat storage amount adjustment unit 80 will be described. When the amount of heat stored in the heat storage tank 50 detected by the multiple heat storage temperature sensors 52 is less than a predetermined value, the CPU 102 activates the third pump 92 and the auxiliary heat source 84. As a result, the third pump 92 pressure-feeds the heat medium in the third circulation pipe 90 in a predetermined direction (the direction of arrow c), and the heat medium circulates between the heat storage tank 50 and the heating heat exchanger 82.

[0094] Specifically, a low-temperature heat medium is supplied from the lower part of the heat storage tank 50 via the feed pipe 90A to the heating heat exchanger 82. As a result, in the heating heat exchanger 82, the heat medium supplied from the heat storage tank 50 is heated by the auxiliary heat source 84. The heat medium heated in the heating heat exchanger 82 is supplied to the upper part of the heat storage tank 50 via the feed pipe 90A of the third circulation pipe 90, and is stored (heat stored) in the heat storage tank 50.

[0095] On the other hand, when the amount of heat stored in the heat storage tank 50 detected by the plurality of heat storage temperature sensors 52 is equal to or greater than a predetermined value, the CPU 102 stops the third pump 92 and the auxiliary heat source 84. This adjusts the amount of heat stored in the heat storage tank 50 to a predetermined value.

[0096] (Action and effect) Next, the operation and effects of this embodiment will be described.

[0097] According to this embodiment, the heat storage tank 50 is connected to the heat source side heat exchanger 32 via a first circulation pipe 40. A first pump 42 is provided on this first circulation pipe 40. Furthermore, the heat storage tank 50 is connected to a heat pump 62 via a second circulation pipe 70. A second pump 72 is provided on this second circulation pipe 70.

[0098] In this embodiment, the first pump 42 is operated to circulate the heat medium between the heat source-side heat exchanger 32 and the heat storage tank 50. Specifically, the low-temperature heat medium is supplied from the lower part of the heat storage tank 50 to the heat source-side heat exchanger 32 via the feed pipe 40A.

[0099] As a result, in the heat source side heat exchanger 32, heat is exchanged between the heat medium supplied from the heat storage tank 50 and the exhaust heat discharged from the heat source equipment 10, and the heat medium is heated. In other words, in the heat source side heat exchanger 32, the exhaust heat generated in the heat source equipment 10 is recovered via the heat medium.

[0100] The heat medium heated in the heat source side heat exchanger 32 is supplied to the upper part of the heat storage tank 50 via the return pipe 40B of the first circulation pipe 40. The heat storage tank 50 stores the heat medium supplied from the heat source side heat exchanger 32. As a result, the exhaust heat is stored in the heat storage tank 50.

[0101] Therefore, in this embodiment, even when there is no heat demand for the heat pump 62 (use-side heat exchanger), the exhaust heat generated in the heat source equipment 10 can be recovered and stored in the heat storage tank 50 stably.

[0102] Next, in this embodiment, the second pump 72 is operated to circulate the heat medium between the heat storage tank 50 and the heat pump 62. Specifically, the heat medium at a predetermined temperature is supplied from the top of the heat storage tank 50 to the heat pump 62 via the feed pipe 70A. The heat pump 62 heats the heat medium supplied from the heat storage tank 50 and supplies it to the utilization facility 16.

[0103] Therefore, in this embodiment, even when the heat source equipment 10 does not generate exhaust heat, the exhaust heat stored in the heat storage tank 50 can be supplied to the heat pump 62 stably.

[0104] In this manner, in this embodiment, the utilization efficiency of the heat generated in the heat source equipment 10 can be improved.

[0105] Here, there is often a mismatch in heat balance between the heat source-side heat exchanger 32 and the heat pump 62. Therefore, when the heat source-side heat exchanger 32 and the heat pump 62 are connected via a single circulation pipe, the temperature of the heat medium flowing through the circulation pipe needs to be constantly adjusted using an auxiliary heat source or the like.

[0106] In contrast to this, in this embodiment, as described above, the heat source side heat exchanger 32 and the heat storage tank 50 are connected via the first circulation piping 40, and the heat pump 62 and the heat storage tank 50 are connected via the second circulation piping 70.

[0107] As a result, regardless of whether there is a heat demand for the heat pump 62, the exhaust heat from the heat source equipment 10 can be stably stored in the heat storage tank 50 by the heat source side heat exchanger 32. Furthermore, regardless of whether there is a heat demand for the heat source equipment 10, the exhaust heat stored in the heat storage tank 50 can be stably supplied to the heat pump 62 in accordance with the heat demand of the utilization equipment 16.

[0108] Therefore, in this embodiment, unlike when the heat source-side heat exchanger 32 and the heat pump 62 are connected via a single circulation pipe, there is no need to constantly adjust the temperature of the heat medium flowing through the circulation pipe using an auxiliary heat source, etc. Therefore, the control of the heat recovery system 20 can be simplified.

[0109] The heat recovery system 20 is also provided with a heat storage amount adjustment unit 80. The heat storage amount adjustment unit 80 can maintain the amount of heat stored in the heat storage tank 50 at a predetermined value.

[0110] As a result, in this embodiment, even when the heat source equipment 10 does not generate heat, for example, a heat medium at a predetermined temperature can be supplied to the heat pump 62 from the heat storage tank 50. This improves the convenience of the heat pump 62 and also reduces damage to the heat pump 62.

[0111] Furthermore, the heat storage tank 50 has multiple phase change material modules 54 built in. The phase change material modules 54 store and release heat without causing a temperature change, so it is possible to suppress sudden temperature changes inside the heat storage tank 50. Therefore, it is possible to stably supply a heat medium within a predetermined temperature range from the heat storage tank 50 to the heat pump 62. Furthermore, the phase change material of the phase change material modules 54 has a larger heat storage capacity per unit volume than a sensible heat storage material. Therefore, it is possible to increase the heat storage efficiency of the heat generated in the heat source equipment 10 while suppressing an increase in the size of the heat storage tank 50.

[0112] Furthermore, the phase change material module 54 stores heat by a phase change of the phase change material. Heat storage by such a phase change does not cause a temperature change. Therefore, the temperature of the heat medium in the heat storage tank 50 is stable, and the heat medium at a predetermined temperature can be stably supplied from the heat storage tank 50 to the heat pump 62.

[0113] Furthermore, a flow rate adjustment valve 46 is provided in the first circulation pipe 40. This flow rate adjustment valve 46 is controlled by the control device 100 so that the heat medium at a predetermined temperature is supplied from the heat source side heat exchanger 32 to the heat storage tank 50. This makes it possible to maintain the temperature of the heat medium stored in the heat storage tank 50 at a predetermined temperature.

[0114] The second circulation pipe 70 is also provided with a bypass pipe 76 and a three-way valve 78. The three-way valve 78 is controlled by the control device 100 so that a heat medium at a predetermined temperature is supplied to the heat pump 62. This prevents damage to the heat pump 62.

[0115] (Variation) Next, a modification of the above embodiment will be described.

[0116] In the above embodiment, the latent heat storage material module 54 is provided in the heat storage tank 50. However, the latent heat storage material module 54 may be provided in the heat storage tank 50 as needed, and may be omitted as appropriate.

[0117] Furthermore, the layout of the pipes and various components of the heat recovery section 30, the heat utilization section 60, and the heat storage amount adjustment section 80 of the heat recovery system 20 can be changed as appropriate.

[0118] In the above embodiment, the heat recovery system 20 is provided with the heat storage amount adjusting unit 80. However, the heat storage amount adjusting unit 80 may be provided in the heat recovery system 20 as needed, and may be omitted as appropriate.

[0119] Although one embodiment of the present invention has been described above, the present invention is not limited to such an embodiment, and one embodiment and various modified examples may be used in appropriate combination, and it goes without saying that the present invention can be implemented in various forms as long as it does not deviate from the gist of the present invention. [Explanation of symbols]

[0120] 10 Heat source equipment (heat source) 20 Heat Recovery System 32 Heat source side heat exchanger 40 First circulation piping 42 First Pump 50 Heat storage tank 54 Phase change material module (phase change material) 62 Heat pump (use side heat exchanger) 70 Second circulation piping 72 Second Pump 80 Heat storage amount adjustment section

Claims

1. a heat source-side heat exchanger that exchanges heat generated by the heat source with a heat medium; a heat storage tank connected to the heat source side heat exchanger via a first circulation pipe and configured to store the heat medium supplied from the heat source side heat exchanger; a first pump provided in the first circulation piping and configured to circulate a heat medium between the heat source side heat exchanger and the heat storage tank; a utilization-side heat exchanger connected to the heat storage tank via a second circulation pipe and utilizing the heat supplied from the heat storage tank; a second pump provided in the second circulation pipe for circulating the heat medium between the heat storage tank and the utilization-side heat exchanger; A heat recovery system comprising:

2. a heat storage amount adjusting unit that adjusts the amount of heat stored in the heat storage tank; The heat recovery system of claim 1 .

3. The heat storage tank has a latent heat storage material that exchanges heat with a heat medium. The heat recovery system according to claim 1 or 2.

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