Waste heat utilization system

Abstract

To provide an exhaust heat utilization system capable of more effectively using exhaust heat.SOLUTION: A chemical heat pump 12 for an exhaust heat utilization system 11 includes: a heat accumulator 21 in which a chemical thermal storage medium HM is accommodated; and a recovery device 31 for recovering steam generated through dehydration reaction of the chemical thermal storage medium HM. The chemical heat pump 12 includes an evaporator 41 supplying steam for hydration reaction with the chemical thermal storage medium HM to the heat accumulator 21. A cooler 13 for the exhaust heat utilization system 11 includes: an energy conversion device 51 for converting thermal energy and electric energy; and an electric storage device 61 electrically connected to the energy conversion device 51. The exhaust heat utilization system 11 includes: a recovery device cooling flow passage L3 for sending a cooling medium from the energy conversion device 51 to the recovery device 31; an external heating path R1 sending heat generated during a heat radiation operation to an external heating target HT; and an internal heating path R2 for sending heat generated during the heat radiation operation to the energy conversion device 51.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a waste heat utilization system equipped with a chemical heat pump. [Background technology]

[0002] As disclosed in Patent Document 1, a chemical heat pump is known as a device that can be used to reuse exhaust heat generated in factories and the like. The chemical heat pump includes a heat accumulator, a recovery device, and an evaporator. The heat accumulator contains a chemical heat storage material that stores heat through a dehydration reaction and releases heat through a hydration reaction. The recovery device recovers steam generated by the dehydration reaction of the chemical heat storage material. The evaporator generates steam to be used in the hydration reaction of the chemical heat storage material. The recovery device of such a chemical heat pump contains a recovery material that undergoes a hydration reaction with the steam generated by the dehydration reaction of the chemical heat storage material, thereby making it possible to easily proceed with the dehydration reaction of the chemical heat storage material. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2019-158299 Summary of the Invention [Problem to be solved by the invention]

[0004] In a waste heat utilization system equipped with a chemical heat pump, it is important to increase the ratio of heat output to heat consumption, i.e., the utilization efficiency of waste heat. Here, in the above-mentioned chemical heat pump, in order to repeatedly use the recovered material stored in the recovery unit, it is necessary to perform a regeneration operation using the waste heat to cause a dehydration reaction. The use of waste heat in such a regeneration operation of the recovered material is one factor that reduces the utilization efficiency of the waste heat. Furthermore, for example, the heat dissipation operation of the waste heat utilization system needs to be stopped when there is no heat demand. Stopping the heat dissipation operation of such a waste heat utilization system increases the time during which the waste heat cannot be utilized. As such, there is still room for improvement in terms of more effective utilization of waste heat. [Means for solving the problem]

[0005] The waste heat utilization system that solves the above problem is equipped with a chemical heat pump and a cooling device. picture, The chemical heat pump includes a heat storage device that accommodates a chemical heat storage material that undergoes a dehydration reaction during a heat storage operation and a hydration reaction during a heat release operation, a recovery device that recovers water vapor generated by the dehydration reaction of the chemical heat storage material, and an evaporator that supplies water vapor to the heat storage device to cause a hydration reaction with the chemical heat storage material, A waste heat utilization system in which a heating medium from an exhaust heat source is sent to the heat accumulator during the heat storage operation to be used for a dehydration reaction of the chemical heat storage material, and is sent to the evaporator during the heat dissipation operation to be used for generating water vapor that undergoes a hydration reaction with the chemical heat storage material, The cooling device includes an energy conversion device that converts thermal energy and electrical energy, and a power storage device electrically connected to the energy conversion device, and the exhaust heat utilization system includes a collector cooling flow path that sends a cooling medium from the energy conversion device to the collector, an external heating path that sends heat generated during the heat dissipation operation to an external heating object, and an internal heating path that sends heat generated during the heat dissipation operation to the energy conversion device.

[0006] According to this configuration, the recovery device can be cooled by the cooling device. This reduces the pressure inside the recovery device, allowing the dehydration reaction of the chemical thermal storage material in the heat storage device to proceed. Therefore, the use of recovery material to reduce the pressure inside the recovery device can be omitted. This eliminates the need for a recovery material regeneration operation that uses exhaust heat, making it possible to improve the efficiency of exhaust heat utilization. Furthermore, the above-mentioned exhaust heat utilization system can send heat generated by the heat dissipation operation of the chemical heat pump to the energy conversion device through an internal heating path. The energy conversion device can convert thermal energy into electrical energy. The obtained electrical energy can be stored in the power storage device. That is, in the above-mentioned exhaust heat utilization system, for example, when there is no heat demand, thermal energy can be used to store electrical energy.

[0007] In the above-mentioned exhaust heat utilization system, the energy conversion device may include a first conversion device that converts thermal energy to kinetic energy and a second conversion device that converts kinetic energy to electrical energy. In this way, the energy conversion device can be configured from, for example, two types of conversion devices.

[0008] The exhaust heat utilization system may further include an external cooling flow path that sends a heat medium from an external heat medium supply unit to an external object to be cooled, and the external cooling flow path may be arranged to pass through the recovery device. With this configuration, the external object to be cooled can be cooled using the recovery device of the chemical heat pump.

[0009] In the above-described exhaust heat utilization system, the power storage device may be electrically connected to an external power supply target and configured to be able to supply electric power to the power supply target. With this configuration, the electric energy stored in the power storage device using the chemical heat pump can be effectively utilized externally. In other words, the exhaust heat can be utilized more effectively.

[0010] In the above-described exhaust heat utilization system, the power storage device may be electrically connected to an external surplus power generation source and configured to store surplus power supplied from the surplus power generation source. With this configuration, the external surplus power can be used to cool the recovery device of the chemical heat pump. In other words, the external surplus power can be effectively used for the heat storage operation. [Effects of the Invention]

[0011] According to the present invention, it is possible to more effectively utilize exhaust heat. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a schematic diagram showing a waste heat utilization system according to a first embodiment. [Figure 2] FIG. 10 is a schematic diagram illustrating a heat storage operation. [Figure 3] FIG. 10 is a schematic diagram illustrating a heat dissipation operation. [Figure 4] FIG. 10 is a schematic diagram illustrating an external cooling operation. [Figure 5] FIG. 10 is a schematic diagram illustrating a power storage operation. [Figure 6] FIG. 3 is a flow chart illustrating the operation of the exhaust heat utilization system. [Figure 7] FIG. 10 is a schematic diagram showing a waste heat utilization system according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0013] (First embodiment) A first embodiment of the exhaust heat utilization system will be described below with reference to the drawings. <Main components of the waste heat utilization system> As shown in Fig. 1, the waste heat utilization system 11 includes a chemical heat pump 12 and a cooling device 13. The chemical heat pump 12 includes a heat accumulator 21, a recovery device 31, and an evaporator 41. The chemical heat pump 12 stores heat using a waste heat source HS, and then releases heat at a temperature higher than that of the waste heat source HS. The cooling device 13 includes an energy conversion device 51 and a power storage device 61.

[0014] The exhaust heat utilization system 11 is equipped with a collector cooling flow path L3 that sends the cooling medium from the energy converter 51 to the collector 31. A pump is provided midway along the collector cooling flow path L3, allowing the cooling medium to circulate between the energy converter 51 and the collector 31. The exhaust heat utilization system 11 is equipped with an external heating path R1 that sends heat generated by the heat dissipation operation of the chemical heat pump 12 to an external heating target HT. The exhaust heat utilization system 11 is equipped with an internal heating path R2 that sends heat generated by the heat dissipation operation of the chemical heat pump 12 to the energy converter 51.

[0015] <Chemical heat pump heat storage unit> The heat accumulator 21 has a chemical heat storage material HM that undergoes a dehydration reaction during heat storage operation of the chemical heat pump 12 and a hydration reaction during heat release operation of the chemical heat pump 12. A well-known solid material can be used as the chemical heat storage material HM. The chemical heat storage material HM may be composed of only a chemical heat storage substance, or may be a material in which a particulate chemical heat storage substance is bound with a water vapor permeable binder such as a water vapor permeable resin. Examples of chemical heat storage materials include alkaline earth metal halides and calcium sulfate. One type of chemical heat storage material HM may be used, or multiple types may be used in combination.

[0016] The dehydration reaction and hydration reaction of calcium chloride, which is a type of chemical heat storage material, are represented by, for example, the following formula (A). CaCl2·H2O+H2O⇔CaCl2·2H2O···(A) The heat accumulator 21 includes a first heat exchanger 22 that exchanges heat with the chemical heat storage material HM. The heat accumulator 21 includes a first container 23 that accommodates the chemical heat storage material HM and the first heat exchanger 22. The first container 23 of the heat accumulator 21 is configured so that water vapor used in the hydration reaction of the chemical heat storage material HM can be introduced. Furthermore, the first container 23 of the heat accumulator 21 is configured so that water vapor generated by the dehydration reaction of the chemical heat storage material HM can be discharged.

[0017] Examples of the first heat exchanger 22 of the heat accumulator 21 include a fin-tube type heat exchanger and a finless heat exchanger. Note that similar heat exchangers can also be used for the heat exchangers described below.

[0018] <Chemical heat pump recovery unit> The recovery device 31 recovers water vapor generated by the dehydration reaction of the chemical thermal storage medium HM in the heat accumulator 21. The recovery device 31 includes a second heat exchanger 32 and a second container 33 that houses the second heat exchanger 32. The water vapor introduced into the recovery device 31 is cooled by the second heat exchanger 32 and recovered as condensed water W1.

[0019] <Chemical heat pump evaporator> The evaporator 41 supplies water vapor to be reacted with the chemical thermal storage material HM to the heat accumulator 21. The evaporator 41 includes a third heat exchanger 42 to which a heating medium is supplied from the exhaust heat source HS, and a third container 43 that houses the third heat exchanger 42. Water W2 in the third container 43 of the evaporator 41 can be heated by the third heat exchanger 42 to generate water vapor.

[0020] <Cooling device> The energy converter 51 in the cooling device 13 converts thermal energy and electrical energy. The energy converter 51 of this embodiment includes a first converter 52 that converts thermal energy and kinetic energy, and a second converter 53 that converts kinetic energy and electrical energy.

[0021] The first conversion device 52 is, for example, a Stirling engine and has a heat absorption side 52a and a cold heat absorption side 52b. The first conversion device 52 also includes a piston, a power transmission unit, and the like (not shown). When kinetic energy is input to the first conversion device 52 from the outside, a temperature difference occurs in which the heat absorption side 52a is lower than the cold heat absorption side 52b. Therefore, the first conversion device 52 can be used as a cooler that cools the heat absorption side 52a. The recovery device 31 of the chemical heat pump 12 can be cooled using this first conversion device 52.

[0022] On the other hand, when the heat absorption side 52a of the first conversion device 52 is heated, thermal energy is generated, which is the temperature difference between the temperature of the cold absorption side 52b and the temperature of the heat absorption side 52a. The first conversion device 52 can convert the thermal energy into kinetic energy and output the kinetic energy.

[0023] The second conversion device 53 converts the kinetic energy input from the first conversion device 52 into electrical energy. The second conversion device 53 also converts the electrical energy input from the power storage device 61 into kinetic energy. As the second conversion device 53, for example, a dynamomotor can be used.

[0024] The power storage device 61 in the cooling device 13 is electrically connected to the energy conversion device 51. More specifically, the power storage device 61 stores electric energy input from the second conversion device 53 of the energy conversion device 51. The power storage device 61 also supplies electric energy to the second conversion device 53. Examples of the power storage device 61 include a lithium ion battery, a redox flow battery, a lead storage battery, a sodium sulfur battery, and a lithium ion capacitor.

[0025] The power storage device 61 of this embodiment is electrically connected to an external power supply target 92 and is configured to be able to supply power to the power supply target 92. <Flow path configuration> Next, a description will be given of the flow path configuration used in each operation of the exhaust heat utilization system 11. The exhaust heat utilization system 11 performs a heat storage operation, a heat dissipation operation, an external cooling operation, and an electricity storage operation.

[0026] First, the flow path used for the heat storage operation of the exhaust heat utilization system 11 will be described. 2, the exhaust heat utilization system 11 has a water vapor recovery flow path L1 that sends water vapor WV1 from the heat accumulator 21 to the recovery device 31. The exhaust heat utilization system 11 has a heat accumulator heating flow path L2 that sends the heating medium from the exhaust heat source HS to the first heat exchanger 22 of the heat accumulator 21. The heat accumulator heating flow path L2 of this embodiment is configured to send the heating medium from the exhaust heat source HS to the evaporator 41 and then to the heat accumulator 21. This heat accumulator heating flow path L2 can also be changed to a flow path that sends the heating medium from the exhaust heat source HS to the heat accumulator 21, for example, without passing through the evaporator 41.

[0027] As described above, the exhaust heat utilization system 11 has the recovery device cooling flow path L3. The recovery device cooling flow path L3 sends the cooling medium from the first conversion device 52 to the second heat exchanger 32 of the recovery device 31. Examples of the cooling medium include water and antifreeze. The exhaust heat utilization system 11 has the conversion device cooling flow path L4 that sends the cooling medium from the cooling source CS to the first conversion device 52.

[0028] Next, the flow paths used for the heat dissipation operation of the exhaust heat utilization system 11 will be described. As shown in FIG. 3, the exhaust heat utilization system 11 has an evaporator heating flow path L5 that sends a heating medium from the exhaust heat source HS to the evaporator 41. The exhaust heat utilization system 11 has a heat accumulator steam flow path L6 that sends water vapor WV2 from the evaporator 41 to the heat accumulator 21. The exhaust heat utilization system 11 has an external heating path R1 that sends heat generated in the heat accumulator 21 to an external heating target HT. In this embodiment, the external heating path R1 is a heat pipe, but it may also be configured to send water vapor generated in the first heat exchanger 22 of the heat accumulator 21 to the heating target HT. The heating target HT is not particularly limited. An example of the heating target HT is a steam generator.

[0029] Next, a flow path used for the external cooling operation of the exhaust heat utilization system 11 will be described. As shown in Fig. 4, the exhaust heat utilization system 11 has an external cooling flow path L7 that sends a heat medium from an external heat medium supply unit 91 to an external object to be cooled CT. The external cooling flow path L7 is arranged to pass through the recovery device 31. This allows the heat medium passing through the external cooling flow path L7 to be cooled by the recovery device 31. For example, a gas such as air can be used as the heat medium. In this case, cold air can be sent to the object to be cooled CT by the external cooling operation.

[0030] Next, the flow path used for the power storage operation of the exhaust heat utilization system 11 will be described. 5, the above-described internal heating path R2 is used in the power storage operation of the exhaust heat utilization system 11. The internal heating path R2 sends heat generated in the heat accumulator 21 to the first conversion device 52 of the energy conversion device 51. The internal heating path R2 of this embodiment is a heat pipe, and is arranged to exchange heat with the heat medium circulation flow path L8 that circulates the heat medium on the heat absorption side 52a of the first conversion device 52. The internal heating path R2 may also be configured to send water vapor generated in the first heat exchanger 22 of the heat accumulator 21 to the first conversion device 52 of the energy conversion device 51.

[0031] In the power storage operation, the evaporator heating flow path L5 and the heat accumulator water vapor flow path L6 are used, as in the heat dissipation operation, and the converter cooling flow path L4 is used, as in the heat storage operation.

[0032] <Overall operation of the waste heat utilization system> Next, an example of the overall operation of the exhaust heat utilization system 11 will be described. As shown in Fig. 6, in the operation of the exhaust heat utilization system 11, first, a first determination step is performed to determine whether or not there is a demand for heat (step S1). If it is determined in the first determination step of step S1 that there is a demand for heat (step S1: YES), the system proceeds to a heat storage operation of step S11. After the heat storage operation of step S11 is performed, the system proceeds to a heat dissipation operation of step S12. After the heat dissipation operation of step S12, the first determination step of step S1 is repeated.

[0033] On the other hand, if it is determined in the first determination step of step S1 that there is no heat demand (step S1: NO), a second determination step is performed to determine whether there is a request to cool the outside (step S2).

[0034] If it is determined in the second determination step of step S2 that there is a request to cool the outside (step S2: YES), the process proceeds to the external cooling operation of step S21. After the external cooling operation of step S21, the first determination step of step S1 is repeated.

[0035] On the other hand, if it is determined in the second determination step of step S2 that there is no external cooling request (step S2: NO), the process proceeds to the power storage operation of step S22. After the power storage operation of step S22, the first determination step of step S1 is repeated.

[0036] <Heat storage operation of the waste heat utilization system> 2, in the heat storage operation (step S2), the water vapor WV1 discharged from the chemical heat storage material HM of the heat accumulator 21 is recovered by the recovery device 31. The water vapor WV1 discharged from the chemical heat storage material HM of the heat accumulator 21 is sent to the recovery device 31 through a water vapor recovery passage L1.

[0037] The water vapor WV1 discharged from the chemical heat storage material HM of the heat accumulator 21 is sent to the recovery device 31, whereby a dehydration reaction of the chemical heat storage material HM occurs. Here, as the dehydration reaction of the chemical heat storage material HM progresses, the temperature of the chemical heat storage material HM decreases. When the temperature of the chemical heat storage material HM becomes lower than the temperature of the heating medium of the exhaust heat source HS, the heating medium is sent from the exhaust heat source HS through the heat accumulator heating flow path L2 to the first heat exchanger 22 of the heat accumulator 21. This makes it possible to promote the dehydration reaction of the chemical heat storage material HM.

[0038] In the heat storage operation, the recovery device 31 is cooled by the cooling device 13. More specifically, the cooling medium cooled on the heat absorption side 52a of the first conversion device 52 of the cooling device 13 is sent to the second heat exchanger 32 of the recovery device 31 through the recovery device cooling flow path L3.

[0039] The heat absorption side 52a of the first conversion device 52 is cooled using electrical energy from the power storage device 61. More specifically, to cool the heat absorption side 52a of the first conversion device 52, first, electrical energy is input from the power storage device 61 to the second conversion device 53. The second conversion device 53 converts the electrical energy into kinetic energy. Next, kinetic energy is input from the second conversion device 53 to the first conversion device 52. The first conversion device 52 converts the kinetic energy into thermal energy. The thermal energy is output as a temperature difference between the temperature of the heat absorption side 52a and the temperature of the cold heat absorption side 52b of the first conversion device 52. At this time, a cooling medium is sent from the cooling source CS to the cold heat absorption side 52b of the first conversion device 52 through the converter cooling flow path L4.

[0040] By such a series of operations of the cooling device 13, the recovery device 31 can be cooled to a temperature of, for example, 10°C or less. Since the saturated water vapor pressure of water at 10°C is 1.2 kPa, for example, if the chemical thermal storage material HM has a water vapor pressure of about 2 kPa when heated with exhaust heat, it is possible to proceed with the dehydration reaction. For example, in the dehydration reaction of calcium chloride represented by the above formula (A), when exhaust heat of 80°C is used, the water vapor pressure of calcium chloride is 2 kPa. Therefore, by using the cooling device 13 to cool the recovery device 31 to about 10°C and reducing the water vapor pressure in the recovery device 31 to about 1.2 kPa, the dehydration reaction of calcium chloride can proceed.

[0041] <Heat dissipation operation of the waste heat utilization system> As shown in Fig. 3, in the heat dissipation operation (step S12), a heating medium is supplied from the exhaust heat source HS to the third heat exchanger 42 of the evaporator 41 through the evaporator heating flow path L5. This causes water vapor WV2 to be generated in the evaporator 41. The water vapor WV2 generated in the evaporator 41 is sent to the heat accumulator 21 through the heat accumulator water vapor flow path L6. This causes a hydration reaction of the chemical thermal storage medium HM in the heat accumulator 21. In the heat dissipation operation, the heat generated in the heat accumulator 21 is sent to the external heating target HT through the external heating path R1.

[0042] <External cooling operation of waste heat utilization system> As shown in Fig. 4, in the external cooling operation (step S21), a heat medium is sent from the external heat medium supply unit 91 to the external cooling target CT through the external cooling flow path L7. The heat medium is cooled by the recovery device 31. In this external cooling operation, the recovery device 31 can be used to cool the external cooling target CT. If the cooling capacity of the recovery device 31 decreases, the recovery device 31 may be cooled using the cooling device 13.

[0043] During this external cooling operation, power may be supplied from the power storage device 61 to the external power supply target 92. In this way, the power storage device 61 can be used as a backup power source for the external power supply target 92, for example.

[0044] <Electricity storage operation of waste heat utilization system> 5, in the electricity storage operation (step S22), a heating medium is supplied from the exhaust heat source HS to the third heat exchanger 42 of the evaporator 41 through the evaporator heating flow path L5. This causes water vapor WV2 to be generated in the evaporator 41. The water vapor WV2 generated in the evaporator 41 is sent to the heat accumulator 21 through the heat accumulator water vapor flow path L6. This causes a hydration reaction of the chemical thermal storage medium HM in the heat accumulator 21 to occur, similarly to the heat release operation (step S12).

[0045] In the power storage operation, heat generated in the heat accumulator 21 is sent to the first conversion device 52 through the internal heating path R2. At this time, the external heating path R1 is closed, and the heat dissipation operation is stopped. Note that the internal heating path R2 is closed during the heat dissipation operation. In other words, by switching between the external heating path R1 and the internal heating path R2, it is possible to switch between the heat dissipation operation and the power storage operation.

[0046] In the power storage operation, a cooling medium is sent from the cooling source CS through the converter cooling flow path L4 to the cold heat absorption side 52b of the first conversion device 52. At this time, in the first conversion device 52, the heat absorption side 52a is heated by the heat generated in the heat accumulator 21, and the thermal energy, which is the temperature difference between the heat absorption side 52a and the cold heat absorption side 52b, is converted into kinetic energy.

[0047] The kinetic energy output from the first conversion device 52 is input to the second conversion device 53. The second conversion device 53 converts the kinetic energy into electrical energy. The electrical energy output from the second conversion device 53 is stored in the power storage device 61.

[0048] <Action and effect> The operation and effects of the first embodiment will be described. (1-1) The exhaust heat utilization system 11 includes a chemical heat pump 12 and a cooling device 13. The chemical heat pump 12 includes a heat accumulator 21, a recovery device 31, and an evaporator 41. The cooling device 13 includes an energy converter 51 that converts thermal energy into electrical energy, and an electricity storage device 61 electrically connected to the energy converter 51. The exhaust heat utilization system 11 includes a recovery device cooling flow path L3 that sends a cooling medium from the energy converter 51 to the recovery device 31. The exhaust heat utilization system 11 includes an external heating path R1 that sends heat generated during heat dissipation to an external heating target HT, and an internal heating path R2 that sends heat generated during heat dissipation to the energy converter 51.

[0049] According to this configuration, the recovery device 31 can be cooled by the cooling device 13. As a result, the pressure inside the recovery device 31 can be reduced, thereby allowing the dehydration reaction of the chemical thermal storage material HM in the heat storage device 21 to proceed. Therefore, the use of a recovery material to reduce the pressure inside the recovery device 31 can be omitted. This eliminates the need for a recovery material regeneration operation that uses exhaust heat, making it possible to improve the efficiency of exhaust heat utilization. Furthermore, the exhaust heat utilization system 11 can send heat generated by the heat dissipation operation of the chemical heat pump 12 to the energy conversion device 51 through the internal heating path R2. The energy conversion device 51 can convert thermal energy into electrical energy. The obtained electrical energy can be stored in the electricity storage device 61. That is, in the exhaust heat utilization system 11, for example, when there is no heat demand, thermal energy can be used to store electrical energy. Therefore, it is possible to more effectively utilize exhaust heat.

[0050] (1-2) The exhaust heat utilization system 11 has an external cooling flow path L7 that sends a heat medium from an external heat medium supply unit 91 to an external object to be cooled CT. The external cooling flow path L7 is arranged to pass through the recovery device 31. In this case, the recovery device 31 of the chemical heat pump 12 can be used to cool the external object to be cooled CT.

[0051] (1-3) The power storage device 61 of the exhaust heat utilization system 11 is configured to be able to supply power to an external power supply target 92. In this case, the electrical energy stored in the power storage device 61 using the chemical heat pump 12 can be effectively utilized externally. In other words, the exhaust heat can be utilized even more effectively.

[0052] (Second embodiment) The second embodiment of the exhaust heat utilization system 11 will be described, focusing on the differences from the first embodiment.

[0053] 7, the exhaust heat utilization system 11 of the second embodiment differs from the exhaust heat utilization system 11 of the first embodiment in the configuration of the cooling device 13. The energy conversion device 51 of the second embodiment includes a third conversion device 54. The third conversion device 54 converts thermal energy and electrical energy.

[0054] The third conversion device 54 is, for example, a thermoelectric element such as a Peltier element, and has a heat absorption side 54a and a cold absorption side 54b. When electrical energy is input to the third conversion device 54 from the outside, a temperature difference occurs in which the heat absorption side 54a is lower than the cold absorption side 54b. Therefore, the third conversion device 54 can be used as a cooler that performs cooling on the heat absorption side 54a. The recovery device 31 of the chemical heat pump 12 can be cooled using this third conversion device 54.

[0055] On the other hand, when the heat absorption side 54a is heated, the third conversion device 54 can output electrical energy converted from thermal energy, which is the temperature difference between the temperature of the cold absorption side 54b and the temperature of the heat absorption side 54a. That is, the energy conversion device 51 of the second embodiment can omit the second conversion device 53 included in the energy conversion device 51 of the first embodiment.

[0056] The power storage device 61 in the cooling device 13 stores the electric energy input from the third conversion device of the energy conversion device 51. The power storage device 61 also supplies the electric energy to the third conversion device .

[0057] The power storage device 61 of the second embodiment is electrically connected to an external surplus power generation source 93 and is configured to be able to store surplus power supplied from the surplus power generation source 93. Examples of the surplus power generation source 93 include a solar power generation system, a wind power generation system, a hydroelectric power generation system, a geothermal power generation system, and a biomass power generation system.

[0058] The operation and effects of the second embodiment will be described. (2-1) The energy conversion device 51 includes the above-described third conversion device 54. In this case, the second conversion device 53 used in the first embodiment is not necessary. This makes it possible to reduce the size of the energy conversion device 51.

[0059] (2-2) The power storage device 61 of the exhaust heat utilization system 11 is configured to be able to store surplus power supplied from an external surplus power generation source 93. In this case, the external surplus power can be used to cool the recovery device 31 of the chemical heat pump 12. In other words, the external surplus power can be effectively used for the heat storage operation.

[0060] (Example of change) The above embodiment may be modified as follows: The above embodiment and the following modifications may be implemented in combination with each other within the scope of technical compatibility.

[0061] In the exhaust heat utilization system 11 of the first embodiment, the power storage device 61 may be electrically connected to the surplus power generation source 93 . In the exhaust heat utilization system 11 of the second embodiment, the power storage device 61 may be electrically connected to the power supply target 92 .

[0062] The surplus power generation source 93 and the power supply target 92 may be omitted. The external cooling passage L7 may be omitted, that is, the external cooling operation in step S21 may be omitted. [Explanation of symbols]

[0063] 11...Waste heat utilization system 12...Chemical heat pump 13…Cooling device 21... Heat storage device 31...Collector 41...Evaporator 51...Energy conversion device 52...First conversion device 53...Second conversion device 54...Third conversion device 61...Electricity storage device 91...Heat medium supply section 92...Electricity supply target 93...Excess electricity generation source CT: cooling target HT: Heating target HM…Chemical heat storage material L3: Collector cooling channel L7: External cooling channel R1: External heating path R2: Internal heating path WV1, WV2...water vapor

Claims

1. A chemical heat pump and a cooling device are provided. The chemical heat pump includes a heat accumulator that accommodates a chemical heat storage material that undergoes a dehydration reaction during a heat storage operation and a hydration reaction during a heat release operation; A recovery vessel for recovering water vapor generated by a dehydration reaction of the chemical heat storage material; an evaporator that supplies water vapor to the heat storage device to cause a hydration reaction with the chemical heat storage material, A waste heat utilization system in which a heating medium from an exhaust heat source is sent to the heat accumulator during the heat storage operation to be used for a dehydration reaction of the chemical heat storage material, and is sent to the evaporator during the heat dissipation operation to be used for generating water vapor that undergoes a hydration reaction with the chemical heat storage material, The cooling device is an energy conversion device that converts thermal energy and electrical energy; a power storage device electrically connected to the energy conversion device, The waste heat utilization system includes: a collector cooling flow path that sends a cooling medium from the energy conversion device to the collector; an external heating path for transmitting the heat generated during the heat dissipation operation to an external heating target; an internal heating path for transmitting heat generated during the heat dissipation operation to the energy conversion device; A waste heat utilization system equipped with:

2. The waste heat utilization system according to claim 1 , wherein the energy conversion device comprises a first conversion device that converts thermal energy to kinetic energy and a second conversion device that converts kinetic energy to electrical energy.

3. 3. The exhaust heat utilization system according to claim 1, further comprising an external cooling flow path that sends a heat medium from an external heat medium supply unit to an external object to be cooled, the external cooling flow path being arranged to pass through the recovery device.

4. The exhaust heat utilization system according to claim 1 , wherein the power storage device is electrically connected to an external power supply target and configured to be able to supply electric power to the power supply target.

5. 5. The exhaust heat utilization system according to claim 1, wherein the power storage device is electrically connected to an external surplus power generation source and configured to be able to store surplus power supplied from the surplus power generation source.

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