Device system and method for storing energy by coupling solar energy with chemical heat pump

Abstract

The invention provides a solar energy coupling chemical heat pump energy storage device system and method. The device system comprises a solar heat collection device, a first heat exchange device, a chemical reaction device, a second heat exchange device, a heat exchange medium storage device and a cooling product storage device. The solar heat collection device is sequentially connected with the first heat exchange device; the first heat exchange device is circularly connected with the chemical reaction device; the chemical reaction device is circularly connected with the second heat exchange device; the second heat exchange device is circularly connected with the heat exchange medium storage device; and the second heat exchange device is sequentially connected with the cooling product storage device. The solar heat collection device and the chemical heat pump system are combined, surplus solar energy in the daytime is stored, the light abandoning phenomenon is reduced, and the large-scale application and popularization prospect is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of solar energy storage, and in particular to a device system and method for solar energy coupled chemical heat pump energy storage. Background Art

[0002] With the rapid consumption of primary energy sources such as coal, oil and natural gas and the resulting serious environmental pollution, renewable energy has developed rapidly. Solar energy, as the largest renewable energy, can reduce human dependence on fossil energy and carbon emissions. However, due to weather and geographical reasons, solar energy utilization has two inherent defects: intermittent and unstable, which poses a great challenge to its further development and causes serious abandonment of solar energy.

[0003] Chemical heat pump energy storage technology utilizes the endothermic and exothermic reactions in the chemical reaction process to convert the excess thermal energy and electrical energy into chemical energy for storage, and converts this other form of energy back into the required thermal energy and electrical energy during peak hours to meet the needs of the grid or users.

[0004] CN110770523A discloses a chemical thermal storage material and a manufacturing method thereof, as well as a chemical heat pump and an operating method thereof, showing a chemical thermal storage material that has a higher reaction rate and can achieve thermal storage at a lower temperature among the thermal storage materials that utilize the dehydration reaction of alkaline earth metal hydroxides, and a chemical heat pump for utilizing the chemical thermal storage material to store and release heat. However, the above patents only disclose the preparation method of the chemical thermal storage material, but not the application method.

[0005] CN113691218A discloses a photovoltaic thermoelectric power generation combined energy storage system based on chemical quality improvement and heat storage, the system includes a photovoltaic thermoelectric power generation subsystem and a chemical quality improvement and heat storage subsystem. It has the functions of solar energy utilization, medium and low temperature thermal energy quality improvement, medium and high temperature thermal energy storage and medium and high temperature thermal energy release, and can significantly increase the temperature of the hot end conduction surface of the thermoelectric battery, thereby increasing the power generation of the thermoelectric battery, and has good economic benefits. The above patents disclose the application scenarios of solar energy coupled with chemical quality improvement and heat storage, but the chemical heat pump is only used as an intermediate medium for quality improvement, and the chemical reaction mostly uses a liquid medium, and the generated reaction products mostly contain hydrogen, and hydrogen storage is difficult and dangerous, with high solid investment and limited application scenarios.

[0006] CN103352814A discloses a composite power generation system combining parabolic trough solar heat collection and chemical heat pump, including a parabolic trough heat collection unit, a chemical heat pump heating and energy storage unit and a power generation unit. The parabolic trough heat collection unit is used to receive and gather solar radiation energy, and convert the received solar radiation energy into medium-temperature heat energy of about 380°C through a heat transfer medium, and then the heat energy is delivered to the chemical heat pump heating and energy storage unit as a medium-temperature heat source. The chemical heat pump heating and energy storage unit uses medium-temperature heat energy as a heat source to drive an endothermic chemical reaction, uses the chemical changes of substances to absorb and release heat, converts the medium-temperature heat energy into chemical energy storage or generates high-temperature heat energy above 500°C, and delivers it to the power generation unit; the power generation unit converts the received heat energy into electrical energy through power equipment such as steam turbines and generator sets. However, the above system has a complex structure and a high investment cost.

[0007] Therefore, it is necessary to develop a solar energy storage system with low investment, green, safe and pollution-free to reduce the occurrence of abandoned light. Summary of the invention

[0008] In view of the problems existing in the prior art, the present invention provides a device system and method for solar energy coupled chemical heat pump energy storage, which couples chemical heat pump technology with solar energy utilization technology, and realizes staggered utilization of solar energy by reasonably setting the connection relationship between heat exchange devices, thereby reducing the phenomenon of abandoned light.

[0009] To achieve this object, the present invention adopts the following technical solutions:

[0010] In a first aspect, the present invention provides a solar energy coupled chemical heat pump energy storage device system, the device system comprising a solar energy collection device, a first heat exchange device, a chemical reaction device, a second heat exchange device, a heat exchange medium storage device and a cooling product storage device;

[0011] The solar energy heat collection device is connected to the first heat exchange device in sequence; the first heat exchange device is circularly connected to the chemical reaction device; the chemical reaction device is circularly connected to the second heat exchange device; the second heat exchange device is circularly connected to the heat exchange medium storage device; the second heat exchange device is connected to the cooling product storage device in sequence.

[0012] The solar energy coupled chemical heat pump energy storage device system described in the present invention includes a solar energy collection device and a chemical reaction device, and is also provided with a heat exchange device, which together realizes the combination of solar energy utilization technology and chemical heat pump energy storage technology, improves the operating efficiency of the chemical heat pump energy storage device and reduces the phenomenon of abandoned light.

[0013] The solar energy coupled chemical heat pump energy storage device system of the present invention adds a chemical heat pump energy storage system to the original solar energy utilization system unit, making maximum use of the original equipment, and the newly added equipment has low processing difficulty, low transformation cost, and good economy of the whole device system.

[0014] The present invention does not limit the solar thermal collection device in detail, and includes a conventional thermal collection system and electrical control facilities, which can realize the utilization of solar energy and generate electrical energy and thermal energy.

[0015] The present invention does not make any specific limitation on the chemical reaction device, which includes a reactor body, chemical reactants, electric heating facilities, etc., and can realize the chemical heat pump function through the endothermic and exothermic reactions of the chemical reactants.

[0016] Preferably, the first heat exchange device includes a heat exchanger and an electric heater arranged around the heat exchanger.

[0017] The first heat exchange device described in the present invention is provided with shell-side inlets and outlets respectively, and heat exchange medium is stored in the shell. Electric heaters are evenly arranged around the heat exchanger, and the heat exchange medium is heated by utilizing the electric energy and thermal energy generated by the solar energy collector. Heat exchange tubes are provided inside the heat exchanger for releasing heat energy during the energy release process.

[0018] Preferably, the first heat exchange device also includes a generator set.

[0019] The present invention does not impose any specific limitation on the generator set, and any generator set that can utilize the heat energy output by the first heat exchange device to release both electrical energy and thermal energy may be used, for example, a Rankine cycle generator set.

[0020] Preferably, the first heat exchange device is connected to a heat exchange medium input pipeline and a heat exchange medium output pipeline respectively.

[0021] Preferably, a first conveying device is provided on the circulation pipeline between the first heat exchange device and the chemical reaction device.

[0022] Preferably, a second conveying device is provided on the circulation pipeline between the chemical reaction device and the second heat exchange device.

[0023] Preferably, a third conveying device is provided on the circulation pipeline between the second heat exchange device and the heat exchange medium storage device.

[0024] Preferably, the third conveying device is a bidirectional conveying device.

[0025] The second heat exchange device of the present invention is connected to the shell inlet and outlet of the chemical reaction device to timely remove the gas and liquid generated by the endothermic reaction and timely deliver the gas and liquid required by the exothermic reaction; a liquid collecting device and a heat exchange pipe are provided inside the second heat exchange device to facilitate timely heat recovery and temporary recovery and storage of reaction products.

[0026] Preferably, a fourth conveying device is provided on the connecting pipeline between the second heat exchange device and the cooling product storage device.

[0027] Preferably, the fourth conveying device is a bidirectional conveying device.

[0028] The present invention preferably uses the third conveying device and the fourth conveying device as bidirectional conveying devices to ensure that the energy storage process and the energy release process of the solar energy coupled chemical heat pump energy storage device system proceed smoothly and stably.

[0029] In a second aspect, the present invention further provides a method for solar-coupled chemical heat pump energy storage, which is performed using the solar-coupled chemical heat pump energy storage device system as described in the first aspect; the method includes an energy storage process and an energy release process.

[0030] Preferably, the energy storage process includes: during the day, the solar thermal collection device generates electrical energy and thermal energy to heat the heat exchange medium in the first heat exchange device; the heated heat exchange medium enters the chemical reaction device to cause the chemical reactants to undergo an endothermic reaction, and the reaction products enter the second heat exchange device to heat the heat exchange medium, the heated heat exchange medium enters the storage device for storage, and the cooled reaction products enter the cooling product storage device.

[0031] Preferably, the energy release process includes: at night, the reaction products in the cooling product storage device enter the second heat exchange device, are heated by the heat exchange medium in the heat exchange medium storage device, and then enter the chemical reaction device to undergo an exothermic reaction; the heat released in the chemical reaction device heats the heat exchange medium and is then stored in the first heat exchange device.

[0032] The solar energy coupled chemical heat pump energy storage method of the present invention utilizes a solar energy collector to absorb solar energy during the day to generate heat energy and electric energy, and utilizes and stores the heat energy through a first heat exchange device, a chemical reaction device, and a second heat exchange device; at night, the solar energy collector stops working, and the heat stored in the heat exchange medium storage device heats the reaction product, which enters the chemical reaction device to undergo an exothermic reaction, thereby realizing the utilization and release of heat. The method of the present invention is simple to operate, convenient to operate and regulate, and the chemical reactants form a cycle in the energy storage and release process, with no additional product generated, and is green and pollution-free.

[0033] The present invention does not limit the heat exchange medium in detail, and any commonly used heat transfer oil, water or molten salt in the art can be used. The heat of the heat exchange medium stored in the first heat exchange device during the energy release process can be supplied to the outside.

[0034] As a preferred technical solution of the present invention, the method includes an energy storage process and an energy release process;

[0035] The energy storage process includes: during the day, the solar thermal collector generates electrical energy and thermal energy to heat the heat exchange medium in the first heat exchange device; the heated heat exchange medium enters the chemical reaction device to cause the chemical reactant to undergo an endothermic reaction, the reaction product enters the second heat exchange device through the second conveying device to heat the heat exchange medium, the heated heat exchange medium enters the storage device for storage, and the cooled reaction product enters the cooling product storage device;

[0036] The energy release process includes: at night, the reaction products in the cooling product storage device are transported into the second heat exchange device by the fourth transport device, and the heat exchange medium in the heat exchange medium storage device is transported into the second heat exchange device by the third transport device. The reaction products are heated and enter the chemical reaction device to undergo an exothermic reaction; the heat released in the chemical reaction device is absorbed by the heat exchange medium transported by the first transport device and then stored in the first heat exchange device.

[0037] Compared with the prior art, the present invention has at least the following beneficial effects:

[0038] (1) The solar energy coupled chemical heat pump energy storage device system provided by the present invention has a reasonable structural design. A chemical heat pump system is added to the original solar energy system unit, which makes the most of the original equipment. The newly added equipment has low processing difficulty, low transformation cost, and good economic efficiency of the entire device system.

[0039] (2) The solar energy coupled chemical heat pump energy storage device system provided by the present invention has a simple operation method, utilizes the advantages of the solar energy collector and the chemical heat pump system, realizes the effective utilization of light energy, and the chemical reactants form a cycle in the energy storage and release process, without the generation of additional products, is green and pollution-free, and is suitable for large-scale promotion and application. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 It is a structural schematic diagram of the solar energy coupled chemical heat pump energy storage device system in Example 1 of the present invention.

[0041] Figure 2 It is a structural schematic diagram of the solar energy coupled chemical heat pump energy storage device system in Example 2 of the present invention.

[0042] In the figure: 1-solar heat collecting device; 2-first heat exchange device; 3-chemical reaction device; 4-second heat exchange device; 5-heat exchange medium storage device; 6-cooling product storage device; 7-first conveying device; 8-second conveying device; 9-third conveying device; 10-fourth conveying device; 11-cooling water input pipeline; 12-cooling water output pipeline; 13-boosting pump; 14-expansion machine; 15-coaxial motor; 16-condenser. DETAILED DESCRIPTION

[0043] The technical solution of the present invention is further described below with reference to the accompanying drawings and through specific implementation methods.

[0044] The present invention is further described in detail below. However, the following examples are only simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention shall be subject to the claims.

[0045] It should be understood that, in the description of the present invention, the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0046] It should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "disposed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0047] Those skilled in the art should understand that the present invention necessarily includes necessary pipelines, conventional valves and general pump equipment for realizing a complete process, but the above content does not belong to the main inventive point of the present invention. Those skilled in the art can add layouts on their own based on the process flow and equipment structure selection, and the present invention does not make special requirements and specific limitations on this.

[0048] Example 1

[0049] This embodiment provides a solar energy coupled chemical heat pump energy storage device system, and its structural schematic diagram is as follows: Figure 1 shown.

[0050] The device system comprises a solar heat collection device 1, a first heat exchange device 2, a chemical reaction device 3, a second heat exchange device 4, a heat exchange medium storage device 5 and a cooling product storage device 6;

[0051] The solar thermal collector 1 is connected in sequence with the first heat exchange device 2; the first heat exchange device 2 is circularly connected with the chemical reaction device 3; the chemical reaction device 3 is circularly connected with the second heat exchange device 4; the second heat exchange device 4 is circularly connected with the heat exchange medium storage device 5; the second heat exchange device 4 is connected in sequence with the cooling product storage device 6.

[0052] The first heat exchange device 2 includes a heat exchanger and an electric heater arranged around the heat exchanger.

[0053] The first heat exchange device 2 is connected to a cooling water input pipe 11 and a cooling water output pipe 12 respectively.

[0054] A first conveying device 7 is provided on the circulation pipeline between the first heat exchange device 2 and the chemical reaction device 3;

[0055] A second conveying device 8 is provided on the circulation pipeline between the chemical reaction device 3 and the second heat exchange device 4 .

[0056] A third conveying device 9 is provided on the circulation pipeline between the second heat exchange device 4 and the heat exchange medium storage device 5. The third conveying device 9 is a bidirectional conveying device.

[0057] A fourth conveying device 10 is provided on the connecting pipeline between the second heat exchange device 4 and the cooling product storage device 6. The fourth conveying device 10 is a bidirectional conveying device.

[0058] This embodiment also provides a method for solar-coupled chemical heat pump energy storage, which is performed using the above-mentioned solar-coupled chemical heat pump energy storage device system.

[0059] In this embodiment, multiple layers of reaction raw material Ca(OH)2 are arranged inside the chemical reaction device 3, and the solid reaction raw material should be a porous medium material. The heat exchange medium in the first heat exchange device 2 and the second heat exchange device 4 is heat transfer oil, and the heat exchange medium with the heat transfer oil in the first heat exchange device 2 is cooling water.

[0060] The method includes an energy storage process and an energy release process;

[0061] The energy storage process includes: during the day, the solar thermal collector 1 generates electrical energy and thermal energy, and the electrical energy drives the electric heater in the first heat exchange device 2 to heat the internal heat transfer oil; the heated heat transfer oil circulates in the chemical reaction device 3 through the first conveying device 7, and at this time, the Ca(OH)2 arranged in the chemical reaction device 3 undergoes an endothermic reaction:

[0062] Ca(OH) 2(s) =CaO (s) +H2O (g) , ΔH=104KJ / mol

[0063] The reaction product CaO is retained in the chemical reaction device 3, and the reaction product H2O (g) The heat transfer oil is transported to the second heat exchange device 4 through the second transport device 8 to heat the heat transfer oil. The heat transfer oil is arranged in countercurrent, with an inlet temperature of 40°C, an outlet temperature of 160°C, and a condensed water temperature of 50°C. The liquid collecting device arranged inside the second heat exchanger 4 separates the condensed water, and the dry air flows back to the chemical reaction device 3 to complete the gas cycle. The heated heat transfer oil enters the storage device 5 for storage, and the condensed water is transported to the cooling product storage device 6 through the fourth transport device 10.

[0064] The energy release process includes: at night, the condensed water in the cooling product storage device 6 is transported into the second heat exchange device 4 by the fourth transport device 10; the third transport device 9 is started in reverse to transport the heat transfer oil in the heat exchange medium storage device 5 into the second heat exchange device 4 for circulation, the condensed water is heated, the inlet water temperature of the second heat exchange device 4 is 48°C, and the inlet temperature of the heat transfer oil is 150°C.

[0065] Start the second conveying device 8. As the air circulates, the water vapor enters the chemical reaction device 3 to generate an exothermic reaction. The reaction temperature is controlled to be 200°C:

[0066] CaO (s) +H2O (g) =Ca(OH) 2(s) , ΔH=-104KJ / mol

[0067] The heat released in the chemical reaction device 3 is absorbed by the heat transfer oil delivered by the first delivery device 7 and then stored in the first heat exchange device 2. The heated air causes the water in the second heat exchange device 4 to evaporate further. By controlling the cooling water flow rate, the inlet temperature of the cooling water connected to the first heat exchange device 2 is 20°C and the outlet water temperature is 120°C.

[0068] Example 2

[0069] This embodiment provides a solar energy coupled chemical heat pump energy storage device system, and its structural schematic diagram is as follows: Figure 2 shown.

[0070] The device system includes a generator set in addition to the first heat exchange device 2. The generator set in this embodiment is a Rankine cycle generator set, including a booster pump 13, a heat exchanger, an expander 14 and a condenser 16 connected in a loop; the expander 14 is connected to a coaxial motor 15; the condenser 16 is respectively connected to a cooling water input pipe 11 and a cooling water output pipe 12, and the rest is the same as in Embodiment 1.

[0071] This embodiment also provides a method for solar-coupled chemical heat pump energy storage, which is performed using the above-mentioned solar-coupled chemical heat pump energy storage device system.

[0072] In this embodiment, multiple layers of reaction raw material Ca(OH)2 are arranged inside the chemical reaction device 3, and the solid reaction raw material should be a porous medium material. The heat exchange medium in the first heat exchange device 2 and the second heat exchange device 4 is heat transfer oil, and the heat exchanger 16 is cooling water.

[0073] The method is different from Example 1 in that: the heat exchange medium in the first heat exchange device 2 is an organic working fluid R600, the working fluid evaporation temperature is 152°C, and the outlet temperature after heat exchange is designed to be 180°C; after heat exchange, R600 enters the expander 14 to perform work and generates electricity through the coaxial motor 15, the exhaust gas enters the condenser 16 for heat exchange, enters the booster pump 13 for pressurization, and then returns to the heat exchanger in the first heat exchange device 2 for circulation; the outlet temperature of the cooling water after heat exchange is 60°C, and hot water is supplied to users.

[0074] In this embodiment, the equipment investment increases and the hot water supply temperature decreases, but additional electricity can be supplied, which is suitable for users with additional demand for electricity.

[0075] In summary, the solar energy coupled chemical heat pump energy storage device provided by the present invention has a reasonable system structure design. By combining a solar energy collector with a chemical heat pump system, surplus solar energy during the day is stored, reducing the phenomenon of abandoned light. It is suitable for medium-scale distributed solar energy storage in parks and other places.

[0076] The applicant declares that the present invention illustrates the detailed structural features of the present invention through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned detailed structural features, that is, it does not mean that the present invention must rely on the above-mentioned detailed structural features to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of the components selected by the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

[0077] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

Claims

1. A solar energy coupled chemical heat pump energy storage device system, characterized in that: The device system includes a solar heat collection device, a first heat exchange device, a chemical reaction device, a second heat exchange device, a heat exchange medium storage device and a cooling product storage device; The solar energy heat collection device is connected to the first heat exchange device in sequence; the first heat exchange device is circularly connected to the chemical reaction device; the chemical reaction device is circularly connected to the second heat exchange device; the second heat exchange device is circularly connected to the heat exchange medium storage device; the second heat exchange device is connected to the cooling product storage device in sequence.

2. The device system according to claim 1, characterized in that: The first heat exchange device includes a heat exchanger and an electric heater arranged around the heat exchanger.

3. The device system according to claim 1 or 2, characterized in that: The first heat exchange device also includes a generator set.

4. The device system according to any one of claims 1 to 3, characterized in that: The first heat exchange device is connected to a heat exchange medium input pipeline and a heat exchange medium output pipeline respectively.

5. The device system according to any one of claims 1 to 4, characterized in that: A first conveying device is provided on the circulation pipeline between the first heat exchange device and the chemical reaction device; Preferably, a second conveying device is provided on the circulation pipeline between the chemical reaction device and the second heat exchange device.

6. The device system according to any one of claims 1 to 5, characterized in that: A third conveying device is provided on the circulation pipeline between the second heat exchange device and the heat exchange medium storage device; Preferably, the third conveying device is a bidirectional conveying device.

7. The device system according to any one of claims 1 to 6, characterized in that: A fourth conveying device is provided on the connecting pipeline between the second heat exchange device and the cooling product storage device; Preferably, the fourth conveying device is a bidirectional conveying device.

8. A method for storing energy by solar energy coupled to a chemical heat pump, characterized in that: The method is carried out using the solar-coupled chemical heat pump energy storage device system described in any one of claims 1 to 7; the method includes an energy storage process and an energy release process.

9. The method according to claim 8, characterized in that The energy storage process includes: during the day, the solar thermal collection device generates electrical energy and thermal energy to heat the heat exchange medium in the first heat exchange device; the heated heat exchange medium enters the chemical reaction device to cause the chemical reactant to undergo an endothermic reaction, and the reaction product enters the second heat exchange device to heat the heat exchange medium, the heated heat exchange medium enters the storage device for storage, and the cooled reaction product enters the cooling product storage device.

10. The method according to claim 8 or 9, characterized in that: The energy release process includes: at night, the reaction products in the cooling product storage device enter the second heat exchange device, are heated by the heat exchange medium in the heat exchange medium storage device, and then enter the chemical reaction device to undergo an exothermic reaction; the heat released in the chemical reaction device heats the heat exchange medium and is then stored in the first heat exchange device.

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