Multi-grade cooling, heating and power flexible supply system based on Carnot cell

Abstract

According to the multi-grade cold-heat-electricity flexible supply system based on the Carnot battery, the cycle characteristic that a Carnot battery system absorbs heat from the low-temperature side and supplies heat to the high-temperature side is utilized, and a cold-heat multi-grade supply and storage system structure capable of providing various forms of energy sources is innovatively designed; multiple functions including charging, power supply, heat supply and cold supply can be flexibly realized only by using one set of system, the equipment and energy storage cost is greatly reduced, the scale of the system can be flexibly adjusted according to needs, geographical and climate condition constraints in different application scenes are overcome, and compared with the prior art, the application of the Carnot battery is expanded, and the application range of the Carnot battery is expanded. And the method has extremely high performance advantages and popularization value.

Description

Technical Field

[0001] The present invention belongs to the technical field of energy storage, and in particular relates to a multi-grade cold, heat and electricity flexible supply system based on Carnot batteries. Background Art

[0002] At present, the flexible supply of heat, cold and electricity of various grades has great application potential in places such as industrial parks, commercial parks and residential areas. However, with the large-scale access of fluctuating renewable energy and the increasing randomness of users' multi-load demands, the mismatch between supply and demand has become more serious, and the demand for energy storage technology has also increased significantly. However, the efficiency of some energy storage systems in the form of Carnot batteries still has a lot of room for improvement. Therefore, how to combine heat, cold and electricity supply technology with energy storage technology to achieve more efficient and lower-cost energy utilization is the key difficulty at present. Summary of the invention

[0003] In view of this, in view of the technical problems existing in this field, the present invention provides a multi-grade cold, heat and electricity flexible supply system based on Carnot batteries, which is composed of a heat pump device, a power generation device, a high-temperature hot tank, a low-temperature hot tank and a cold tank;

[0004] The heat pump device is connected to the cold tank, the high-temperature hot tank and the low-temperature hot tank respectively, and is used to make the heat pump working medium circulate to exchange heat with the cold storage medium in the cold tank, release heat to the heat storage medium to heat the high-temperature hot tank, and absorb heat from the heat storage medium from the low-temperature hot tank;

[0005] The cold tank is used for refrigeration and heat exchange between the cold storage medium and the heat storage medium, transferring the heat to the heat pump device, and storing low-temperature cold energy;

[0006] The high-temperature heat tank is used to store high-temperature or medium-temperature heat energy through heat exchange between the heat storage medium and the heat pump working fluid, and to expand the heat storage medium and the power generation working fluid to do work and drive the power generation device to generate electricity;

[0007] The low temperature heat tank is used to store medium temperature heat energy by heat exchange between the heat storage medium and the power generation medium after expansion and work, and to store medium temperature cold energy by heat exchange between the heat storage medium and the cold storage medium;

[0008] The system realizes four working modes of charging, cooling, heating and power supply through heat pump circulation and heat exchange between heat pump working fluid, heat storage medium, cold storage medium and power generation working fluid;

[0009] In charging mode, the heat pump device uses external input electric energy to drive the work, and stores the heat energy in the high-temperature hot tank through heat exchange between the heat pump working fluid and the heat storage medium; at the same time, the heat pump device also makes the heat pump working fluid absorb heat from the cold storage medium, so that the cold tank cools down and stores low-temperature cold energy;

[0010] In cooling mode, the cold tank provides low-temperature cold energy to the outside of the system, and the low-temperature hot tank provides medium-temperature cold energy to the outside of the system as needed;

[0011] In heating mode, the high-temperature heat tank provides high-temperature or medium-temperature heat energy to the outside of the system, and the low-temperature heat tank provides medium-temperature heat energy to the outside of the system as needed;

[0012] In the power supply mode, the high-temperature heat storage medium in the high-temperature hot tank exchanges heat with the power generation working fluid, causing it to expand and do work and drive the power generation device to output electrical energy to the outside, and the heat storage medium that has been cooled after heat exchange is stored in the low-temperature hot tank.

[0013] Furthermore, the heat pump cycle of the system is specifically selected from any one of the following types: subcritical cycle, transcritical cycle, cascade cycle, multi-stage compression cycle, intermediate heat recovery cycle, etc.

[0014] Furthermore, the power generation cycle of the system is specifically selected from any one of the following types: Rankine cycle, Brayton cycle, organic Rankine cycle, flash cycle, organic flash cycle, etc.

[0015] Furthermore, the cold storage medium is specifically selected from hot cold storage medium, latent heat cold storage medium and the like.

[0016] Furthermore, the heat storage medium is specifically selected from sensible heat storage medium, latent heat storage medium and the like.

[0017] The multi-grade cold, heat and electricity flexible supply system based on the Carnot battery provided by the present invention above utilizes the cyclic characteristics of the Carnot battery system that absorbs heat from the low-temperature side and supplies heat to the high-temperature side, and innovatively designs a system structure that can provide various forms of energy and multi-grade cold and heat supply and storage. Only one set of system is used to flexibly realize multiple functions including charging, power supply, heating and cooling, which greatly reduces the equipment and energy storage costs. The system scale can be flexibly adjusted according to needs, overcoming the constraints of geographical and climatic conditions in different application scenarios. Compared with the existing technology, the use of Carnot batteries has been expanded, and it has extremely high performance advantages and promotion value. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A schematic diagram of a multi-grade cold, heat and electricity flexible supply system based on Carnot batteries provided by the present invention;

[0019] Explanation of the accompanying numbers: 1-power generation device, 2-heat pump device, 3-high-temperature hot tank, 4-low-temperature hot tank, 5-cold tank. DETAILED DESCRIPTION

[0020] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "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 components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0022] The present invention provides a multi-grade cold, heat and electricity flexible supply system based on Carnot batteries, such as Figure 1 As shown, it is composed of a heat pump device 2, a power generation device 1, a high-temperature hot tank 3, a low-temperature hot tank 4 and a cold tank 5;

[0023] The heat pump device 2 is connected to the cold tank 5, the high-temperature hot tank 3 and the low-temperature hot tank 4 respectively, and is used to circulate the heat pump working fluid such as R1233zd (E) to exchange heat with the cold storage medium in the cold tank 5, release heat to the heat storage medium to heat the high-temperature hot tank 3, and absorb heat from the heat storage medium from the low-temperature hot tank 4;

[0024] The cold tank 5 is used for refrigeration and heat exchange between the cold storage medium and the heat storage medium, transferring the heat to the heat pump device 2, and storing low-temperature cold energy;

[0025] The high-temperature heat tank 3 is used to store high-temperature or medium-temperature heat energy through heat exchange between the heat storage medium and the heat pump working fluid, and to expand the heat storage medium and the power generation working fluid such as R1234ze(E) to perform work, and drive the power generation device 1 to operate and generate electricity;

[0026] The low temperature heat tank 4 is used to store medium temperature heat energy by heat exchange between the heat storage medium and the power generation medium after expansion and work, and to store medium temperature cold energy by heat exchange between the heat storage medium and the cold storage medium;

[0027] The system realizes four working modes of charging, cooling, heating and power supply through heat pump circulation and heat exchange between heat pump working fluid, heat storage medium, cold storage medium and power generation working fluid;

[0028] In charging mode, the heat pump device 2 is driven by external input electric energy to store heat energy in the high-temperature hot tank 3 through heat exchange between the heat pump working fluid and the heat storage medium; at the same time, the heat pump device 2 also makes the heat pump working fluid absorb heat from the cold storage medium, so that the cold tank 5 cools down and stores low-temperature cold energy (such as cold energy below 5°C);

[0029] In the cooling mode, the cold tank 5 provides low-temperature cold energy to the outside of the system, and the low-temperature hot tank 4 provides medium-temperature cold energy (such as 5-15°C cold energy) to the outside of the system as needed;

[0030] In the heating mode, the high temperature heat tank 3 provides high temperature or medium temperature heat energy (such as heat energy of 90-150°C) to the outside of the system, and the low temperature heat tank 4 provides medium temperature heat energy (such as heat energy of 50-90°C) to the outside of the system as needed;

[0031] In the power supply mode, the high-temperature heat storage medium in the high-temperature heat tank 3 exchanges heat with the power generation working fluid, causing it to expand and do work and drive the power generation device 1 to output electrical energy to the outside, and the heat storage medium that has been cooled after heat exchange is stored in the low-temperature heat tank 4.

[0032] In a preferred embodiment of the present invention, the heat pump cycle of the system is specifically selected from any one of the following types: subcritical cycle, transcritical cycle, cascade cycle, multi-stage compression cycle, intermediate heat recovery cycle, etc.

[0033] In a preferred embodiment of the present invention, the power generation cycle of the system is specifically selected from any one of the following types: Rankine cycle, Brayton cycle, organic Rankine cycle, flash cycle, organic flash cycle, etc.

[0034] In a preferred embodiment of the present invention, the cold storage medium is specifically selected from a hot cold storage medium, a latent heat cold storage medium, and the like.

[0035] In a preferred embodiment of the present invention, the heat storage medium is specifically selected from sensible heat storage medium, latent heat storage medium and the like.

[0036] It should be understood that the size of the serial numbers of the steps in the embodiment of the present invention does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiment of the present invention.

[0037] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. Multi-grade cold, heat and electricity flexible supply system based on Carnot battery, characterized by: It consists of a heat pump device, a power generation device, a high-temperature hot tank, a low-temperature hot tank and a cold tank; The heat pump device is connected to the cold tank, the high-temperature hot tank and the low-temperature hot tank respectively, and is used to make the heat pump working medium circulate to exchange heat with the cold storage medium in the cold tank, release heat to the heat storage medium to heat the high-temperature hot tank, and absorb heat from the heat storage medium from the low-temperature hot tank; The cold tank is used for refrigeration and heat exchange between the cold storage medium and the heat storage medium, transferring the heat to the heat pump device, and storing low-temperature cold energy; The high-temperature heat tank is used to store high-temperature or medium-temperature heat energy through heat exchange between the heat storage medium and the heat pump working fluid, and to expand the heat storage medium and the power generation working fluid to do work and drive the power generation device to generate electricity; The low temperature heat tank is used to store medium temperature heat energy by heat exchange between the heat storage medium and the power generation medium after expansion and work, and to store medium temperature cold energy by heat exchange between the heat storage medium and the cold storage medium; The system realizes four working modes of charging, cooling, heating and power supply through heat pump circulation and heat exchange between heat pump working fluid, heat storage medium, cold storage medium and power generation working fluid; In charging mode, the heat pump device uses external input electric energy to drive the work, and stores the heat energy in the high-temperature hot tank through heat exchange between the heat pump working fluid and the heat storage medium; at the same time, the heat pump device also makes the heat pump working fluid absorb heat from the cold storage medium, so that the cold tank cools down and stores low-temperature cold energy; In cooling mode, the cold tank provides low-temperature cold energy to the outside of the system, and the low-temperature hot tank provides medium-temperature cold energy to the outside of the system as needed; In heating mode, the high-temperature heat tank provides high-temperature or medium-temperature heat energy to the outside of the system, and the low-temperature heat tank provides medium-temperature heat energy to the outside of the system as needed; In the power supply mode, the high-temperature heat storage medium in the high-temperature hot tank exchanges heat with the power generation working fluid, causing it to expand and do work and drive the power generation device to output electrical energy to the outside, and the heat storage medium that has been cooled after heat exchange is stored in the low-temperature hot tank.

2. The system according to claim 1, characterized in that: The heat pump cycle of the system is specifically selected from any one of a subcritical cycle, a transcritical cycle, a cascade cycle, a multi-stage compression cycle, and an intermediate heat recovery cycle.

3. The system according to claim 1, characterized in that: The power generation cycle of the system is specifically selected from any one of the Rankine cycle, Brayton cycle, organic Rankine cycle, flash cycle, and organic flash cycle.

4. The system according to claim 1, characterized in that: The cold storage medium is specifically selected from any one of a hot cold storage medium and a latent heat cold storage medium.

5. The system according to claim 1, characterized in that: The heat storage medium is specifically selected from any one of a sensible heat storage medium and a latent heat storage medium.

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