A compressed cycle molten salt heat pump energy storage system and an automatic water injection device

Abstract

The present invention relates to the field of molten salt energy storage, and discloses a molten salt heat pump energy storage system with a compression cycle, including: an electric heating component, which is used for the main heating components, and its energy sources include power supply during night valley hours, wind power supply, hydraulic power supply and solar power supply; a high-temperature molten salt tank, which is used for storing molten salt with an initial high temperature; a heat exchange component, which is used for transferring part of the heat of the high-temperature molten salt to the normal-temperature water; a low-temperature molten salt tank, which is used for storing the low-temperature molten salt after heat exchange; a water injection tank, which is used for storing the injected water source to support the input of external water sources and the output of internal water sources; the present invention can extract the low-temperature heat in the low-temperature molten salt tank, and together with the residual heat after participating in heat exchange with the high-temperature steam tank, dock it to a recompressor for recompression, convert it into medium-temperature steam, recycle the low-grade heat source, improve the utilization rate of low-grade heat energy, and prevent the waste of low-grade heat energy.

Description

Technical Field

[0001] The present invention relates to the technical field of molten salt energy storage, and specifically to a molten salt heat pump energy storage system with a compression cycle and an automatic water injection device. Background Art

[0002] Molten salt heat storage realizes the storage and release of thermal energy through the temperature change, phase change or chemical reaction of the heat storage medium. The heat storage medium absorbs energy such as electric energy and radiant energy and stores it in the medium. When the ambient temperature is lower than the medium temperature, the heat storage medium can release the thermal energy. It is the mainstream technical direction for large-scale medium and high-temperature heat storage, and is divided into sensible heat storage, latent heat storage and thermochemical heat storage. At present, the sensible heat storage technology has the highest maturity, lower price and wider application. Latent heat storage is a research hotspot, while thermochemical heat storage is not yet mature. Molten salt is a commonly used medium and high-temperature sensible heat storage medium, which has a wide liquid temperature range, large heat storage temperature difference and high heat storage density, and is suitable for large-scale medium and high-temperature heat storage projects;

[0003] However, most of the existing molten salt heat pump energy storage systems lack measures for re-compressing and recycling the heat of the low-temperature molten salt after heat exchange and the residual heat of steam, resulting in ineffective utilization of low-grade thermal energy and waste of resources. There are also no measures for automatically replenishing the heat exchange water and giving timely alarm feedback for abnormal states. Summary of the Invention

[0004] (1) Technical problems to be solved: Aiming at the above-mentioned shortcomings of the existing technology, the present invention provides a molten salt heat pump energy storage system with a compression cycle and an automatic water injection device, which can effectively solve the problems that most of the existing molten salt heat pump energy storage systems lack measures for re-compressing and recycling the heat of the low-temperature molten salt after heat exchange and the residual heat of steam, resulting in ineffective utilization of low-grade thermal energy and waste of resources, and lack measures for automatically replenishing the heat exchange water and giving timely alarm feedback for abnormal states.

[0005] (2) Technical solutions: To achieve the above objectives, the present invention is realized through the following technical solutions.

[0006] The present invention discloses a molten salt heat pump energy storage system with a compression cycle, including:

[0007] An electric heating component, used as the main heating part, and its energy sources include off-peak power supply at night, wind power supply, hydraulic power supply and solar power supply;

[0008] A high-temperature molten salt tank, used for storing molten salt at an initial high temperature;

[0009] A heat exchange component, used for transferring part of the heat of the high-temperature molten salt to the normal-temperature water;

[0010] A low-temperature molten salt tank, used for storing low-temperature molten salt after heat exchange;

[0011] Water injection tank, used to store the injected water source, supporting the input of external water source and the output of internal water source;

[0012] Steam storage component, used to store the high-temperature steam generated during the heat exchange process;

[0013] Supply end, as the heat supply output end, providing the reflux circulating water;

[0014] Recompressor, used to recompress the residual low-temperature steam generated after the high-temperature steam tank participates in the heat exchange and the low-temperature steam generated after the low-temperature molten salt in the low-temperature molten salt tank participates in the heat exchange to generate medium-temperature steam;

[0015] Low-temperature steam generation component, used to absorb the low-temperature steam in the low-temperature molten salt tank and store it temporarily;

[0016] Condensate tank, used to store the condensate generated after heat exchange.

[0017] Furthermore, the electric heating component is connected to the high-temperature molten salt tank through a pipeline medium, the input end of the high-temperature molten salt tank is connected to the input end of the heat exchange component through a pipeline medium, the output end of the heat exchange component is connected to the input end of the supply end through a pipeline medium, the output end of the water injection tank is connected to the input end of the heat exchange component through a pipeline medium, the output water end of the reflux circulating water of the supply end is connected to the input end of the heat exchange component through a pipeline medium, the output end of the heat exchange component is connected to the input end of the low-temperature molten salt tank through a pipeline medium, the output end of the low-temperature molten salt tank is connected to the input end of the low-temperature steam generation component through a pipeline medium, the output end of the low-temperature steam generation component is connected to the input end of the recompressor through a pipeline medium, the pipeline medium connecting the heat exchange component and the supply end outputs the output end of the steam storage component, the output end of the steam storage component is connected to the input end of the recompressor, the output end of the recompressor is connected to the input end of the steam storage component, the output end of the steam storage component is connected to the input end of the condensate tank, and the output end of the low-temperature molten salt tank is connected to the input end of the electric heating component.

[0018] Furthermore, the steam storage component includes a high-temperature steam tank and a medium-temperature steam tank. The high-temperature steam tank is used to store high-temperature steam, the medium-temperature steam tank is used to store medium-temperature steam, the output end of the high-temperature steam tank is communicated with the input end of the supply end, and the output end of the medium-temperature steam tank is communicated with the input end of the recompressor.

[0019] Furthermore, the heat exchange component adopts a regenerative heat exchanger, and the low-temperature steam generation component adopts a direct contact heat exchanger.

[0020] An automatic water injection device, comprising:

[0021] Induction module, used to sense the water level condition of the water injection tank and collect data;

[0022] A feedback module, configured to generate corresponding instructions based on the data collected by the sensing module and transmit them.

[0023] A water injection module, configured to import external water source into the water injection tank after receiving a start instruction.

[0024] An alarm module, configured to detect and remind of abnormal water injection status.

[0025] Furthermore, the sensing module is deployed on the water injection tank, the feedback module is connected to the sensing module via a wireless network, the feedback module is electrically connected to the water injection module, the feedback module is connected to the alarm module via a wireless network, the water injection module is deployed on the condensate tank, and the water injection module is connected to the water injection tank via a pipeline medium.

[0026] Furthermore, the feedback module conducts three data feedbacks from the start to the end stage, including: before water injection stage, reaching the predetermined water injection value stage, and terminating water injection stage.

[0027] Furthermore, the triggering interval of the sensing module is 3 - 5S, and the triggering interval of the sensing module is remotely edited through a program.

[0028] Furthermore, after the feedback module issues data, it synchronously generates a mirror file and submits it to the local storage end.

[0029] Furthermore, the alarm methods of the alarm module include: light alarm, voice alarm, and submitting warning information to the management end.

[0030] (III) Advantageous Effects: By adopting the technical solution provided by the present invention, compared with the known prior art, the following advantageous effects are achieved.

[0031] 1. By adding a low-temperature steam generation component and a recompressor, the present invention extracts low-temperature heat in the low-temperature molten salt tank, and together with the residual heat after participating in heat exchange in the high-temperature steam tank, docks with the recompressor for recompression, converting it into medium-temperature steam, so that the device can recycle the heat of the low-temperature molten salt after heat exchange and the residual heat of the high-temperature steam through recompression, improving the utilization rate of low-grade heat energy and preventing waste of low-grade heat energy.

[0032] 2. By means of automatically injecting water into the water injection tank, the present invention senses the water level of the water injection tank through the sensing module. When the water level is insufficient, information is fed back through the feedback module, and then the water injection module injects water, extracts steam condensate from the condensate tank, and the alarm module alarms and reminds of abnormal water injection, so that the device can automatically supplement heat exchange water and give timely alarm feedback on abnormal status. Description of the Drawings

[0033] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the accompanying drawings required for the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other accompanying drawings can also be obtained based on these drawings.

[0034] Figure 1 It is a schematic structural diagram of a compressed cycle molten salt heat pump energy storage system and an automatic water injection device;

[0035] Figure 2 It is a schematic flow diagram of the operation process of an automatic water injection device;

[0036] The reference numerals in the figure respectively represent: 1, electric heating component; 2, high-temperature molten salt tank; 3, heat exchange component; 4, low-temperature molten salt tank; 5, water injection tank; 6, steam storage component; 61, high-temperature steam tank; 62, medium-temperature steam tank; 7, supply end; 8, recompressor; 9, low-temperature steam generation component; 10, condensate tank; 11, induction module; 12, feedback module; 13, water injection module; 14, alarm module. Detailed implementation manners

[0037] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0038] The following further describes the present invention with reference to embodiments. Embodiment

[0039] A compressed cycle molten salt heat pump energy storage system according to this embodiment, as Figure 1 shown, includes:

[0040] An electric heating component 1, used as the main heating part, and its energy sources include power supply during off-peak hours at night, wind power supply, hydraulic power supply, and solar power supply;

[0041] A high-temperature molten salt tank 2, used for storing molten salt with an initial high temperature;

[0042] A heat exchange component 3, used for transferring part of the heat of the high-temperature molten salt to normal-temperature water;

[0043] A low-temperature molten salt tank 4, used for storing molten salt with a low temperature after heat exchange;

[0044] The water injection tank 5 is used to store the injected water source and support the input of external water sources and the output of internal water sources;

[0045] The steam storage component 6 is used to store the high-temperature steam generated during the heat exchange process;

[0046] The supply end 7, as the heat supply output end, provides the return circulating water;

[0047] The recompressor 8 is used to recompress the residual low-temperature steam generated after the high-temperature steam tank participates in heat exchange and the low-temperature steam generated after the low-temperature molten salt in the low-temperature molten salt tank 4 participates in heat exchange to generate medium-temperature steam;

[0048] The low-temperature steam generation component 9 is used to absorb the low-temperature steam in the low-temperature molten salt tank 4 and store it temporarily;

[0049] The condensate tank 10 is used to store the condensate generated after heat exchange.

[0050] As Figure 1 shown, the electric heating component 1 and the high-temperature molten salt tank 2 are connected through a pipeline medium. The input end of the high-temperature molten salt tank 2 and the heat exchange component 3 are connected through a pipeline medium. The output end of the heat exchange component 3 and the input end of the supply end 7 are connected through a pipeline medium. The output end of the water injection tank 5 and the input end of the heat exchange component 3 are connected through a pipeline medium. The output water end of the return circulating water of the supply end 7 and the input end of the heat exchange component 3 are connected through a pipeline medium. The output end of the heat exchange component 3 and the input end of the low-temperature molten salt tank 4 are connected through a pipeline medium. The output end of the low-temperature molten salt tank 4 and the input end of the low-temperature steam generation component 9 are connected through a pipeline medium. The output end of the low-temperature steam generation component 9 and the input end of the recompressor 8 are connected through a pipeline medium. The pipeline medium connecting the heat exchange component 3 and the supply end 7 is connected to the output end of the steam storage component 6. The output end of the steam storage component 6 is connected to the input end of the recompressor 8. The output end of the recompressor 8 is connected to the input end of the steam storage component 6. The output end of the steam storage component 6 is connected to the input end of the condensate tank 10. The output end of the low-temperature molten salt tank 4 is connected to the input end of the electric heating component 1.

[0051] The steam storage component 6 includes a high-temperature steam tank 61 and a medium-temperature steam tank 62. The high-temperature steam tank 61 is used to store high-temperature steam. The medium-temperature steam tank 62 is used to store medium-temperature steam. The output end of the high-temperature steam tank 61 is connected to the input end of the supply end 7. The output end of the medium-temperature steam tank 62 is connected to the input end of the recompressor 8.

[0052] The heat exchange component 3 uses a regenerative heat exchanger, and the low-temperature steam generation component 9 uses a direct contact heat exchanger.

[0053] In the specific implementation of this embodiment, an external energy source is used to heat the molten salt in the high-temperature molten salt tank 2 by the electric heating component 1, and then it is input into the heat exchange component 3 for heat exchange. The high-temperature steam enters the steam storage component 6 and is stored in the high-temperature steam tank 61. The heat exchange water is provided by the water injection tank 5. During the steam collection process, the generated condensate is collected by the condensate tank 10 and provided to the supply end 7. The high-temperature steam in the high-temperature steam tank 61 exchanges heat with the return water at the supply end 7. After heat exchange, the low-temperature molten salt enters the low-temperature molten salt tank 4. The low-temperature steam generation component 9 is started to collect the low-temperature steam and input it into the recompressor 8. The residual steam in the high-temperature steam tank 61 also enters the recompressor 8. After recompression, medium-temperature steam is generated and stored in the medium-temperature steam tank 62.

[0054] Extract the low-temperature heat in the low-temperature molten salt tank 4 and, together with the residual heat after participating in heat exchange in the high-temperature steam tank 61, connect to the recompressor 8 for recompression, converting it into medium-temperature steam, enabling the device to recycle the heat of the low-temperature molten salt and the residual heat of the high-temperature steam after heat exchange through recompression, improving the utilization rate of low-grade heat energy and preventing waste of low-grade heat energy. Embodiment

[0055] This embodiment also provides an automatic water injection device, as Figure 1 and Figure 2 shown, including:

[0056] The induction module 11 is used to sense the water level condition of the water injection tank 5 and collect data;

[0057] The feedback module 12 is used to generate corresponding instructions for the data collected by the induction module 11 and transmit them;

[0058] The water injection module 13 is used to introduce external water sources into the water injection tank 5 after receiving the start instruction;

[0059] The alarm module 14 is used to detect and remind of abnormal water injection states.

[0060] As Figure 1 shown, the induction module 11 is deployed on the water injection tank 5. The feedback module 12 is connected to the induction module 11 through a wireless network. The feedback module 12 is electrically connected to the water injection module 13. The feedback module 12 is connected to the alarm module 14 through a wireless network. The water injection module 13 is deployed on the condensate tank 10. The water injection module 13 is connected to the water injection tank 5 through pipeline media.

[0061] The feedback module 12 conducts three data feedbacks from the start to the end stage, including: the pre-water injection stage, the stage of reaching the predetermined water injection value, and the stage of terminating water injection.

[0062] The triggering interval of the induction module 11 is 3 - 5S, and the triggering interval of the induction module 11 is remotely edited through a program.

[0063] After the feedback module 12 sends down data, it synchronously generates an image file and submits it to the local storage end.

[0064] The alarm methods of the alarm module 14 include: light alarm, voice alarm, and submitting warning information to the management end.

[0065] In the specific implementation of this embodiment, the water level of the water injection tank 5 is sensed by the induction module 11. When the water level is insufficient, information is fed back through the feedback module 12, and then the water injection module 13 injects water and extracts the steam condensate in the condensate tank 10. After reaching the predetermined water injection value, the water injection stops, and the alarm module 14 alarms and reminds of abnormal water injection, so that the device can automatically supplement the heat exchange water and give timely alarm feedback on the abnormal state.

[0066] In summary, an external energy source is used to heat the molten salt in the high-temperature molten salt tank 2 by the electric heating component 1, and then it is input into the heat exchange component 3 for heat exchange. The high-temperature steam enters the steam storage component 6 and is stored in the high-temperature steam tank 61. The heat exchange water is provided by the water injection tank 5. During the steam collection process, the generated condensate is collected by the condensate tank 10 and provided to the supply end 7. The high-temperature steam in the high-temperature steam tank 61 exchanges heat with the return water from the supply end 7. The heat-exchanged low-temperature molten salt enters the low-temperature molten salt tank 4. The low-temperature steam generation component 9 is started to collect and input the low-temperature steam into the recompressor 8, and the residual steam in the high-temperature steam tank 61 also enters the recompressor 8. After recompression, medium-temperature steam is generated and stored in the medium-temperature steam tank 62;

[0067] Extract the low-temperature heat in the low-temperature molten salt tank 4 and, together with the residual heat after participating in heat exchange in the high-temperature steam tank 61, dock with the recompressor 8 for recompression to be converted into medium-temperature steam, so that the device can recycle the heat of the low-temperature molten salt and the residual heat of the high-temperature steam after heat exchange through recompression, improving the utilization rate of low-grade heat energy and preventing waste of low-grade heat energy;

[0068] The water level of the water injection tank 5 is sensed by the induction module 11. When the water level is insufficient, information is fed back through the feedback module 12, and then the water injection module 13 injects water and extracts the steam condensate in the condensate tank 10. After reaching the predetermined water injection value, the water injection stops, and the alarm module 14 alarms and reminds of abnormal water injection, so that the device can automatically supplement the heat exchange water and give timely alarm feedback on the abnormal state.

[0069] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements will not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A compressed cycle molten salt heat pump energy storage system, characterized in that, Comprising: An electric heating component (1) for the main heating part, and its energy sources include power supply during off-peak hours at night, wind power supply, hydraulic power supply, and solar power supply; A high-temperature molten salt tank (2) for storing molten salt at an initial high temperature; A heat exchange component (3) for transferring part of the heat of the high-temperature molten salt to normal-temperature water; A low-temperature molten salt tank (4) for storing low-temperature molten salt after heat exchange; A water injection tank (5) for storing the injected water source to support the input of external water sources and the output of internal water sources; A steam storage component (6) for storing high-temperature steam generated during the heat exchange process; A supply end (7) as a heat supply output end to provide return circulating water; A recompressor (8) for recompressing the residual low-temperature steam generated after the high-temperature steam tank participates in heat exchange and the low-temperature steam generated after the low-temperature molten salt in the low-temperature molten salt tank (4) participates in heat exchange to generate medium-temperature steam; A low-temperature steam generation component (9) for absorbing the low-temperature steam in the low-temperature molten salt tank (4) and storing it temporarily; A condensate tank (10) for storing the condensate generated after heat exchange.

2. The molten salt heat pump energy storage system with a compression cycle according to claim 1, wherein The electric heating component (1) is connected to the high-temperature molten salt tank (2) through a pipeline medium, the input end of the high-temperature molten salt tank (2) is connected to the input end of the heat exchange component (3) through a pipeline medium, the output end of the heat exchange component (3) is connected to the input end of the supply end (7) through a pipeline medium, the output end of the water injection tank (5) is connected to the input end of the heat exchange component (3) through a pipeline medium, the output water end of the return circulating water of the supply end (7) is connected to the input end of the heat exchange component (3) through a pipeline medium, the output end of the heat exchange component (3) is connected to the input end of the low-temperature molten salt tank (4) through a pipeline medium, the output end of the low-temperature molten salt tank (4) is connected to the input end of the low-temperature steam generation component (9) through a pipeline medium, the output end of the low-temperature steam generation component (9) is connected to the input end of the recompressor (8) through a pipeline medium, the pipeline medium connecting the heat exchange component (3) and the supply end (7) is connected to the output end of the steam storage component (6), the output end of the steam storage component (6) is connected to the input end of the recompressor (8), the output end of the recompressor (8) is connected to the input end of the steam storage component (6), the output end of the steam storage component (6) is connected to the input end of the condensate tank (10), and the output end of the low-temperature molten salt tank (4) is connected to the input end of the electric heating component (1).

3. A molten salt heat pump energy storage system with a compression cycle according to claim 1, characterized in that, The steam storage component (6) includes a high-temperature steam tank (61) and a medium-temperature steam tank (62). The high-temperature steam tank (61) is used for storing high-temperature steam, the medium-temperature steam tank (62) is used for storing medium-temperature steam, the output end of the high-temperature steam tank (61) is communicated with the input end of the supply end (7), and the output end of the medium-temperature steam tank (62) is communicated with the input end of the recompressor (8).

4. A compressed cycle molten salt heat pump energy storage system according to claim 1, wherein The heat exchange component (3) adopts a regenerative heat exchanger, and the low-temperature steam generation component (9) adopts a direct contact heat exchanger.

5. An automatic water injection device, which is an automatic water injection device for a compressed cycle molten salt heat pump energy storage system according to any one of claims 1-4, characterized in that, Comprising: An induction module (11) for sensing the water level condition of the water injection tank (5) and collecting data; A feedback module (12) for generating corresponding instructions from the data collected by the sensing module (11) and transmitting them; A water injection module (13) for introducing external water sources into the water injection tank (5) after receiving a start instruction; An alarm module (14) for detecting and alerting abnormal water injection states.

6. The automatic water injection device according to claim 5, characterized in that, The sensing module (11) is deployed on the water injection tank (5). The feedback module (12) is connected to the sensing module (11) via a wireless network. The feedback module (12) is electrically connected to the water injection module (13). The feedback module (12) is connected to the alarm module (14) via a wireless network. The water injection module (13) is deployed on the condensate tank (10). The water injection module (13) is connected to the water injection tank (5) via a pipeline medium.

7. An automatic water injection device according to claim 5, characterized in that, The feedback module (12) performs three data feedbacks from the start to the end stage, including: the pre-water injection stage, the stage of reaching the predetermined water injection value, and the stage of terminating water injection.

8. An automatic water injection device according to claim 5, wherein, The triggering interval of the sensing module (11) is 3 - 5S, and the triggering interval of the sensing module (11) is remotely edited through a program.

9. The automatic water injection device according to claim 5, characterized in that, After the feedback module (12) issues data, it synchronously generates an image file and submits it to the local storage end.

10. An automatic water injection device according to claim 5, characterized in that, The alarm methods of the alarm module (14) include: light alarm, voice alarm, and submitting warning information to the management end.

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