Heat pump heat storage, liquid air energy storage and thermal power generating unit coupling method and related device

Abstract

The invention discloses a heat pump heat storage and liquid air energy storage and thermal power generating unit coupling method and related device.The device comprises a thermal power generating unit system, a liquid air energy storage system and a heat pump heat storage system, and the thermal power generating unit system is connected with the liquid air energy storage system, the heat pump heat storage system and an external power grid; according to the method and the related device, ternary coupling of heat pump heat storage, liquid air energy storage and a thermal power generating unit can be achieved, and meanwhile the problems of unit peak regulation capacity, energy storage efficiency and peak output are solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of energy conversion and storage, and relates to a method for coupling heat pump heat storage with liquid air energy storage and a thermal power unit, and related devices. Background Art

[0002] With the large-scale integration of renewable energy into the power system, grid volatility has increased, placing higher demands on the peak-shaving capabilities of traditional thermal power plants. However, thermal power plants experience significant efficiency reductions under low-load conditions. Currently, liquid air energy storage and heat pump thermal storage technologies have been coupled with thermal power plants, but each has its limitations.

[0003] Liquid air energy storage technology compresses, cools, and liquefies air to store energy. When needed, the liquid air is heated and expanded to generate electricity. During the energy storage process, the compressor generates a significant amount of compression heat, which, if not utilized, would result in wasted energy. Furthermore, during the energy release process, the air cools down after expansion, requiring an external heat source to improve efficiency. Research has shown that for every 100°C increase in air temperature, the efficiency of liquid air energy storage increases by approximately 8%. When the expander inlet air temperature reaches 350°C, the efficiency of liquid air energy storage can reach 65%.

[0004] Heat pump thermal storage technology can upgrade low-grade thermal energy to high-grade heat and store it, allowing it to be used to recover waste heat from low-temperature flue gas and other sources in thermal power plants. Currently, there are technical solutions that couple heat pump thermal storage with thermal power units, primarily for heating the unit's feedwater or heating systems.

[0005] Existing technical solutions for liquid air energy storage coupled with thermal power units require the use of extraction steam to heat the expanded air, resulting in reduced peak output and efficiency. Combining heat pump thermal storage with liquid air energy storage primarily utilizes the heat pump to upgrade and store the heat of compression, which is then used to heat the expanded air. However, a system that combines heat pump thermal storage, liquid air energy storage, and thermal power units to simultaneously address peak load regulation, energy storage efficiency, and peak output remains unavailable. Summary of the Invention

[0006] The purpose of the present invention is to overcome the shortcomings of the above-mentioned prior art and provide a method and related device for coupling heat pump heat storage with liquid air energy storage and thermal power units. This method and related device can realize the ternary coupling of heat pump heat storage, liquid air energy storage and thermal power units, and at the same time solve the problems of unit peak-shaving capacity, energy storage efficiency and peak output.

[0007] To achieve the above-mentioned objectives, the present invention discloses a coupling system of heat pump heat storage, liquid air energy storage and thermal power unit, comprising a thermal power unit system, a liquid air energy storage system and a heat pump heat storage system, wherein the thermal power unit system is connected to the liquid air energy storage system, the heat pump heat storage system and the external power grid, and the liquid air energy storage system is connected to the heat pump heat storage system.

[0008] The present invention discloses a method for coupling heat pump heat storage with liquid air energy storage and a thermal power unit, including a grid load valley period and a grid load peak period.

[0009] Furthermore, the specific process of the grid load low period is as follows:

[0010] Start the liquid air energy storage system to convert electrical energy into liquid air for storage, while recovering compression heat and heating condensate in the thermal power unit system;

[0011] Start the heat pump heat storage system to extract low-grade heat energy from the flue gas of the thermal power unit system, and store it in the high-temperature heat storage device within the heat pump heat storage system after upgrading the quality of the heat pump;

[0012] With the combined effect of the liquid air energy storage system and the heat pump heat storage system, the load of the thermal power unit system can be reduced to below the designed minimum technical output.

[0013] Furthermore, during the low load period of the power grid, the actual load P 实际 =P 机组 -P 液空 -P 热泵 , where P 机组 is the power generation load of the thermal power unit system; P 液空 P is the power consumption of the compressor of the liquid air energy storage system; 热泵 is the power consumption of the heat pump thermal storage system.

[0014] Furthermore, during the peak load period of the power grid, the specific working process is as follows:

[0015] Increase the thermal power generation system to full load operation;

[0016] The liquid air energy storage system begins to release energy, and the liquid air vaporizes and enters the expansion unit in the liquid air energy storage system to generate electricity;

[0017] The high-temperature heat stored in the heat pump thermal storage system is used to heat the low-temperature air after expansion in the liquid air energy storage system;

[0018] When the heat stored in the heat pump storage system is insufficient, the extraction steam from the thermal power unit system is activated as a supplementary heat source.

[0019] Furthermore, during the peak load period of the power grid, the total output power P 实际 =P机组 +P 液 null.

[0020] Furthermore, according to the operating status of the thermal power unit system, the liquid air energy storage system and the heat pump heat storage system, the distribution and flow of heat among the thermal power unit system, the liquid air energy storage system and the heat pump heat storage system are optimized to maximize energy utilization efficiency.

[0021] Furthermore, the load distribution among the thermal power unit system, liquid air energy storage system and heat pump thermal storage system is optimized according to the grid demand and the efficiency characteristics of each subsystem.

[0022] The present invention discloses a computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps of the method for coupling heat pump heat storage with liquid air energy storage and a thermal power unit are implemented.

[0023] The present invention discloses a computer-readable storage medium storing a computer program. When the computer program is executed by a processor, the steps of the method for coupling heat pump heat storage with liquid air energy storage and a thermal power unit are implemented.

[0024] The present invention has the following beneficial effects:

[0025] During specific operation, the method and related devices for coupling heat pump heat storage with liquid air energy storage and a thermal power unit described in the present invention connect the thermal power unit system and the liquid air energy storage system through the heat pump heat storage system, thereby improving both the deep peak-shaving efficiency of the thermal power unit and the efficiency of the liquid air energy storage system while ensuring peak power supply capacity. The system has significant technical advantages, economic rationality, and feasibility. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The accompanying drawings, which constitute part of the present invention, are intended to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are intended to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0027] Figure 1 It is a structural diagram of the present invention. DETAILED DESCRIPTION

[0028] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0029] In the description of the present invention, it is to be understood that the terms “include” and “comprise” indicate the presence of the described features, wholes, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or collections thereof.

[0030] It should also be understood that the terms used in the present specification are only for the purpose of describing particular embodiments and are not intended to limit the present invention. As used in the present specification and the appended claims, the singular forms "a", "an", and "the" are intended to include the plural forms unless the context clearly indicates otherwise.

[0031] It should be further understood that the term "and / or" as used in the present specification and the appended claims refers to and includes any and all possible combinations of one or more of the associated listed items. For example, A and / or B may represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in the present invention generally indicates that the associated objects are in an "or" relationship.

[0032] It should be understood that although the terms "first," "second," and "third" may be used to describe preset ranges in embodiments of the present invention, these preset ranges should not be limited to these terms. These terms are merely used to distinguish one preset range from another. For example, without departing from the scope of embodiments of the present invention, the first preset range may also be referred to as the second preset range, and similarly, the second preset range may also be referred to as the first preset range.

[0033] The word "if," as used herein, may be interpreted as "at the time of" or "when" or "in response to determining" or "in response to detecting," depending on the context. Similarly, the phrases "if it is determined" or "if (stated condition or event) is detected" may be interpreted as "when it is determined" or "in response to the determination" or "when detecting (stated condition or event)" or "in response to detecting (stated condition or event)," depending on the context.

[0034] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0035] The accompanying drawings illustrate various schematic diagrams of structures according to embodiments disclosed herein. These figures are not drawn to scale; for clarity, some details are exaggerated and some details may be omitted. The shapes of the various regions and layers shown in the figures, as well as their relative sizes and positional relationships, are merely exemplary and may deviate in practice due to manufacturing tolerances or technical limitations. Those skilled in the art may design regions / layers with different shapes, sizes, and relative positions as needed.

[0036] Example 1

[0037] refer to Figure 1 The heat pump heat storage, liquid air energy storage and thermal power unit coupling system described in the present invention includes a thermal power unit system, a liquid air energy storage system and a heat pump heat storage system, wherein the thermal power unit system is connected to the liquid air energy storage system, the heat pump heat storage system and the external power grid, and the liquid air energy storage system is connected to the heat pump heat storage system.

[0038] The thermal power unit system includes a boiler, a steam turbine, a generator, a condenser, a feed water heater and a flue gas system.

[0039] The liquid air energy storage system includes an air compressor, a cooling system, a liquid air storage tank, an expansion unit and a heat exchanger.

[0040] The heat pump heat storage system includes a mechanical compression heat pump, a high-temperature heat storage device, a heat exchanger, etc.

[0041] Example 2

[0042] The method for coupling heat pump heat storage with liquid air energy storage and a thermal power unit according to the present invention comprises the following steps:

[0043] 1) Grid load low period (system energy storage stage)

[0044] During the off-peak period of the power grid, the system operates as follows:

[0045] 11) Start the liquid air energy storage system to convert electrical energy into liquid air for storage, while recovering compression heat and heating condensate in the thermal power unit system;

[0046] 12) Start the heat pump heat storage system to extract low-grade heat energy from the flue gas of the thermal power unit system, and store it in the high-temperature heat storage device within the heat pump heat storage system after upgrading the quality of the heat pump;

[0047] 13) Under the joint action of the liquid air energy storage system and the heat pump heat storage system, the load of the thermal power unit can be reduced to below the designed minimum technical output, but maintained at a high relative load level and maintain high operating efficiency.

[0048] In this mode, the actual load of the thermal power generation system is: P 实际 =P 机组 -P 液空 -P 热泵 , where P 实际 is the actual power load received by the grid; P 机组 is the power generation load of the thermal power unit system; P 液空 P is the power consumption of the compressor of the liquid air energy storage system; 热泵 The power consumption of the heat pump thermal storage system;

[0049] 2) Grid load peak period (system energy release stage)

[0050] During the peak load period of the power grid, the system operates as follows:

[0051] 1) Increase the thermal power generation system to full load operation;

[0052] 2) The liquid air energy storage system begins to release energy, and the liquid air vaporizes and enters the expansion unit in the liquid air energy storage system to generate electricity;

[0053] 3) The high-temperature heat (approximately 200°C) stored in the heat pump thermal storage system is used to heat the low-temperature air after expansion in the liquid air energy storage system, improving the subsequent expansion efficiency;

[0054] 4) When the heat stored in the heat pump storage system is insufficient, the steam extraction from the thermal power unit system is used as a supplementary heat source.

[0055] In this mode, the total output power of the system is:

[0056] P 实际 =P 机组 +P 液空

[0057] This system adopts a coordinated control strategy, and the main control objectives include:

[0058] 1) Load distribution optimization: Optimize the load distribution among the thermal power generation system, liquid air energy storage system, and heat pump thermal storage system based on grid demand and the efficiency characteristics of each subsystem;

[0059] 2) Heat flow optimization: Based on the operating status of the thermal power unit system, the liquid air energy storage system, and the heat pump thermal storage system, the heat distribution flow between the thermal power unit system, the liquid air energy storage system, and the heat pump thermal storage system is optimized to maximize energy utilization efficiency;

[0060] 3) Operation mode switching control: According to the changes in grid load, smoothly switch between different operation modes to avoid shocks.

[0061] The present invention achieves significant technical effects by performing ternary coupling of a heat pump heat storage system, a liquid air energy storage system, and a thermal power unit system:

[0062] 1a) Improvement of peak load efficiency of thermal power units:

[0063] 11a) During the off-peak period of the power grid, the heat pump thermal storage system and the liquid air energy storage system work together to further reduce the actual output of the thermal power unit system by about 10-15%;

[0064] 12a) The thermal power unit system itself is maintained at a relatively high load (relative to the designed minimum technical output), and the unit coal consumption of power generation is reduced by about 5-8%. The comprehensive peak-shaving capacity of the system is improved by 20-30%, significantly enhancing the regulation capacity of the power grid.

[0065] 2a) Heat recovery and utilization effect:

[0066] 21a) The heat pump thermal storage system recovers low-temperature heat (approximately 80-120°C) from flue gas and upgrades it to high-temperature heat energy storage at approximately 200°C. The typical COP value of the heat pump thermal storage system can reach 2, significantly improving thermal energy utilization efficiency.

[0067] 22a) The compression heat of the liquid air energy storage system is used to heat the condensate of the generator set, thereby improving the thermal efficiency of the generator set by approximately 0.5-1 percentage points.

[0068] 3a) Peak power generation capacity guarantee effect:

[0069] 31a) During peak hours of the power grid, the liquid air energy storage system uses a heat source of approximately 200°C provided by the heat pump thermal storage system to heat the expanded air. The heated vaporized air enters the expansion unit, significantly increasing power generation.

[0070] 32a) Reducing or avoiding the use of extraction steam from the unit ensures the maximum output capacity of the unit's steam turbine; the system's peak power output capacity increases by 5-10%.

[0071] 4a) Liquid air energy storage efficiency improvement effect:

[0072] 41a) The heat source provided by the heat pump thermal storage system raises the temperature of the expanded air to approximately 200°C. The efficiency of liquid air energy storage is improved by 8 percentage points compared to traditional liquid air energy storage systems.

[0073] 42a) When combined with partial extraction steam heating to reach 350℃, the liquid air energy storage efficiency can be further improved by about 9%.

[0074] 5a) Economic and Environmental Benefits: The investment cost of a heat pump thermal storage system is approximately 50-70% lower than that of a liquid air energy storage system. The system's improved peak-shaving efficiency, improved liquid air energy storage efficiency, and increased peak power generation capacity shorten the heat pump thermal storage system's payback period to approximately 0.5-1.5 years. The system's annual comprehensive coal savings are approximately 3-5%, correspondingly reducing unit CO2 emissions.

[0075] 6a) Improved system flexibility: The ternary coupling system can flexibly adjust the operating status of each subsystem according to grid demand; adapt to various peak-shaving and frequency-regulation scenarios, and enhance the system's ability to cope with fluctuations in renewable energy. System response time is optimized, and the coordinated operation of heat pump thermal storage and liquid air energy storage enables rapid load adjustment.

[0076] Example 3

[0077] A computer device includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps of the method for coupling heat pump thermal storage with liquid air energy storage and a thermal power unit are implemented. The memory may include internal memory, such as a high-speed random access memory, and may also include non-volatile memory, such as at least one disk storage device. The processor, network interface, and memory are interconnected via an internal bus. The internal bus may be an industrial standard architecture bus, a peripheral component interconnect standard bus, an extended industrial standard architecture bus, etc. The bus may be divided into an address bus, a data bus, a control bus, etc. The memory is used to store programs. Specifically, the program may include program code, and the program code includes computer operating instructions. The memory may include internal memory and non-volatile memory, and provides instructions and data to the processor.

[0078] Example 4

[0079] A computer-readable storage medium stores a computer program that, when executed by a processor, implements the steps of the method for coupling heat pump thermal storage with liquid air energy storage and a thermal power plant. Specifically, the computer-readable storage medium includes, but is not limited to, volatile memory and / or non-volatile memory. The volatile memory may include random access memory (RAM) and / or cache memory, etc. The non-volatile memory may include read-only memory (ROM), a hard disk, flash memory, an optical disk, a magnetic disk, etc.

[0080] Those skilled in the art will appreciate that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application can adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code.

[0081] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the steps in the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0082] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0083] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1The steps for the function specified in one or more boxes.

[0084] Those skilled in the art will readily identify other embodiments of the present invention after considering the specification and disclosure of the invention. This application is intended to cover any variations, uses, or adaptations of the present invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein. The description and examples are to be considered as exemplary only, with the true scope and spirit of the invention being indicated by the following claims.

[0085] It should be understood that the present invention is not limited to the exact construction described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present invention is limited only by the appended claims.

[0086] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any simple modification, change and equivalent structural change made to the above embodiment based on the technical essence of the present invention shall still fall within the scope of protection of the technical solution of the present invention.

Claims

1. A heat pump heat storage, liquid air energy storage and thermal power unit coupling system, characterized in that: It includes a thermal power unit system, a liquid air energy storage system and a heat pump heat storage system, wherein the thermal power unit system is connected to the liquid air energy storage system, the heat pump heat storage system and the external power grid, and the liquid air energy storage system is connected to the heat pump heat storage system.

2. A method for coupling heat pump heat storage with liquid air energy storage and thermal power generation units, characterized in that: The heat pump heat storage, liquid air energy storage and thermal power unit coupling system according to claim 1 includes a grid load valley period and a grid load peak period.

3. The method for coupling heat pump heat storage with liquid air energy storage and thermal power generation units according to claim 2, characterized in that: The specific process of the grid load low period is as follows: Start the liquid air energy storage system to convert electrical energy into liquid air for storage, while recovering compression heat and heating condensate in the thermal power unit system; Start the heat pump heat storage system to extract low-grade heat energy from the flue gas of the thermal power unit system, and store it in the high-temperature heat storage device within the heat pump heat storage system after upgrading the quality of the heat pump; With the combined effect of the liquid air energy storage system and the heat pump heat storage system, the load of the thermal power unit system can be reduced to below the designed minimum technical output.

4. The method for coupling heat pump heat storage, liquid air energy storage and thermal power generation unit according to claim 2, characterized in that: During the low load period of the power grid, the actual load P 实际 = P unit - P liquid air - P heat pump, where P unit is the power generation load of the thermal power unit system; P liquid air is the power consumption of the compressor of the liquid air energy storage system; P 热泵 is the power consumption of the heat pump thermal storage system.

5. The method for coupling heat pump heat storage, liquid air energy storage and thermal power generation unit according to claim 2, characterized in that: During the peak load period of the power grid, the specific working process is as follows: Increase the thermal power generation system to full load operation; The liquid air energy storage system begins to release energy, and the liquid air vaporizes and enters the expansion unit in the liquid air energy storage system to generate electricity; The high-temperature heat stored in the heat pump thermal storage system is used to heat the low-temperature air after expansion in the liquid air energy storage system; When the heat stored in the heat pump storage system is insufficient, the extraction steam from the thermal power unit system is activated as a supplementary heat source.

6. The method for coupling heat pump heat storage, liquid air energy storage and thermal power generation unit according to claim 2, characterized in that: During the peak load period of the power grid, the total output power of the system P 实际 =P 机组 +P Liquid Air.

7. The method for coupling heat pump heat storage, liquid air energy storage and thermal power generation unit according to claim 2, characterized in that: According to the operating status of the thermal power unit system, liquid air energy storage system and heat pump thermal storage system, the distribution and flow of heat among the thermal power unit system, liquid air energy storage system and heat pump thermal storage system are optimized to maximize energy utilization efficiency.

8. The method for coupling heat pump heat storage, liquid air energy storage and thermal power generation unit according to claim 2, characterized in that: According to the grid demand and the efficiency characteristics of each subsystem, the load distribution between the thermal power unit system, liquid air energy storage system and heat pump thermal storage system is optimized.

9. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the computer program, the steps of the method for coupling heat pump heat storage with liquid air energy storage and a thermal power unit as described in any one of claims 2 to 8 are implemented.

10. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the steps of the method for coupling heat pump heat storage with liquid air energy storage and a thermal power unit as described in any one of claims 2 to 8 are implemented.

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