Multi-grade cooling, heating and power collaborative management system for energy hub

Abstract

An energy hub-oriented multi-grade cooling, heating and power collaborative management system comprises a high-temperature compressor, a low-temperature expansion machine, a cascade heat storage unit, a cascade cold storage unit, a heat energy recovery heat exchanger, a cold energy recovery heat exchanger, a low-temperature compressor, a high-temperature expansion machine, a heat supply heat exchanger, a cold supply heat exchanger, a generator and a heat exchanger. The cascade heat / cold storage unit and the modular energy recovery device are constructed, wide-temperature-range energy storage from-120 DEG C deep cooling to 500 DEG C high temperature is achieved, and flexible storage, conversion and on-demand supply of electric energy, heat energy and cold energy are supported.

Description

Technical Field

[0001] The present invention relates to a technology in the field of energy management and energy storage, specifically a multi-grade cooling, heating and power coordinated management system for energy hubs. Background Art

[0002] As the global energy mix shifts toward a low-carbon future, the installed capacity of renewable energy sources, particularly wind and photovoltaics, continues to expand. However, their output fluctuates significantly due to natural constraints, exacerbating peak-to-valley variations in the power grid and increasing pressure on peak-shaving. This leads to significant wind and solar curtailment, while the utilization efficiency of low-grade energy sources, such as waste heat from industrial parks and liquefied natural gas vaporization cooling, remains low. This contradiction stems from the traditional energy system's extensive management of multi-grade energy. Existing energy storage technologies, such as pumped hydro and compressed air storage, are limited by geographical conditions and response speed, making it difficult to match dynamic load demands. Furthermore, combined heat, cooling, and power systems generally utilize homogeneous heat / cold storage devices, which cannot achieve fine-grained energy grade grading. Summary of the Invention

[0003] In response to the problems of low energy utilization and insufficient coordination of heat, cooling and electricity in existing technologies, the present invention proposes a multi-grade coordinated management system for heat, cooling and electricity for energy hubs. By constructing cascade heat storage / cold storage units and modular energy recovery devices, it achieves energy storage in a wide temperature range from deep cooling at -120°C to high temperature at 500°C, and supports flexible storage, conversion and on-demand supply of electrical energy, thermal energy and cold energy.

[0004] The present invention is achieved through the following technical solutions:

[0005] The present invention relates to a multi-grade cold, heat and electricity coordinated management system for energy hubs, comprising: a high-temperature compressor, a low-temperature expander, a cascade heat storage unit, a cascade cold storage unit, a heat recovery heat exchanger, a cold recovery heat exchanger, a low-temperature compressor, a high-temperature expander, a heating heat exchanger, a cooling heat exchanger, a generator and a heat exchanger.

[0006] The cascade heat storage unit is composed of multiple heat storage devices connected in series, wherein: each heat storage device is encapsulated with phase change materials with different phase change temperatures, and the phase change temperatures decrease successively along the flow direction of the working fluid during the energy storage process to achieve cascade heat storage.

[0007] The cascade cold storage unit is composed of multiple cold storage devices connected in series, wherein: each cold storage device is encapsulated with phase change materials with different phase change temperatures, and the phase change temperatures increase successively along the flow direction of the working medium during the energy storage process to achieve cascade cold storage. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 Schematic diagram of the energy storage circuit structure of the system of the present invention;

[0009] Figure 2 This is a schematic diagram of the energy release circuit structure of the system of the present invention;

[0010] In the figure: 1 high-temperature compressor, 2 low-temperature expander, 3 cascade heat storage unit, 4 cascade cold storage unit, 5 heat recovery heat exchanger, 6 cold recovery heat exchanger, 7 low-temperature compressor, 8 high-temperature expander, 9 heating heat exchanger, 10 cooling heat exchanger, 11 generator, 12-13 heat exchanger, 16 heat source, 17 cooling source, 18 heat demand side, 19 cooling demand side. DETAILED DESCRIPTION

[0011] like Figure 1 and Figure 2 As shown, this embodiment involves a multi-grade cold, heat and power coordinated management system for energy hubs, including: a high-temperature compressor 1, a cascade heat storage unit 3, a first heat exchanger 12, a low-temperature expander 2, a cascade cold storage unit 4, and a second heat exchanger 13, which are connected in sequence to form a loop, wherein: during the energy storage process, the high-temperature compressor 1, the cascade heat storage unit 3, the heat exchanger 12, the low-temperature expander 2, the cascade cold storage unit 4, the heat exchanger 13, and the high-temperature compressor 1 are connected in sequence to form a closed loop; during the energy release process, the cascade cold storage unit 4, the low-temperature compressor 7, the heat exchanger 14, the cascade heat storage unit 3, the high-temperature expander 8, the heat exchanger 15, and the cascade cold storage unit 4 are connected in sequence to form a closed loop, and the output end of the high-temperature expander 8 is connected to the generator 11.

[0012] Between the heat storage devices of the cascade heat storage unit 3, there are provided heat recovery heat exchangers 5 for inputting industrial waste heat, peak-shaving heat energy from coal-fired power plants or solar heat into heat storage devices of corresponding grades, and heat supply heat exchangers 9 for supplying heat energy to the outside.

[0013] A cold energy recovery heat exchanger 6 for inputting the cold energy of liquefied natural gas vaporization or the residual cold energy of cold chain transportation into the cold storage device of the corresponding grade and a cold supply heat exchanger 10 for supplying cold energy to the outside are provided between the cold storage devices of the cascade cold storage unit 4.

[0014] The cascade heat storage unit 3 is composed of a plurality of heat storage devices connected in series, wherein each heat storage device is encapsulated with a phase change material with a different phase change temperature, and the phase change temperature decreases successively along the flow direction of the working medium during the energy storage process.

[0015] The cascade cold storage unit 4 is composed of a plurality of cold storage devices connected in series, wherein each cold storage device is encapsulated with a phase change material with a different phase change temperature, and the phase change temperature increases sequentially along the flow direction of the working medium during the energy storage process.

[0016] Through specific practical experiments, in an environment that includes an industrial park power grid, a waste heat pipeline network, and a liquefied natural gas storage station, multi-grade cooling, heating, and power coordinated management was carried out, including:

[0017] Energy storage stage: The off-peak electricity of the external grid drives the high-temperature compressor 1 to compress the argon working fluid to 1.1 MPa and 550°C. When flowing through the cascade heat storage unit 3, it releases heat to the 500°C, 300°C, and 100°C heat storage devices in sequence; the normal temperature and high-pressure working fluid is expanded to 0.11 MPa and -125°C through the low-temperature expander 2, and the cold energy is stored in the -120°C, -80°C, and -10°C cold storage devices of the cascade cold storage unit 4; the coal-fired peak-shaving steam (320°C) is directly injected into the second-stage heat storage device of the cascade heat storage unit through the heat recovery heat exchanger 5; the cold energy of the vaporization of liquefied natural gas (-162°C) is introduced into the first-stage cold storage device through the cold energy recovery heat exchanger 6.

[0018] Energy release stage: After absorbing -120°C cold energy from the cascade cold storage unit 4, the argon working medium at room temperature and pressure is pressurized to 1.1 MPa and 50°C by the low-temperature compressor 7. After passing through the heat exchanger 14, the working medium enters the cascade heat storage unit 3 to absorb 500°C heat energy, and then drives the high-temperature expander 8, which drives the generator 11 to generate electricity.

[0019] The second-stage heat storage device of the cascade heat storage unit 3 outputs 150°C steam for industrial drying through the heat supply heat exchanger 9, and the third-stage heat storage device outputs 80°C hot water for regional heating; the third-stage cold storage device of the cascade cold storage unit 4 provides 7°C chilled water for central air conditioning through the cold supply heat exchanger 10.

[0020] The above-mentioned specific implementation can be partially adjusted in different ways by those skilled in the art without departing from the principles and purpose of the present invention. The scope of protection of the present invention shall be based on the claims and shall not be limited by the above-mentioned specific implementation. All implementation schemes within its scope shall be subject to the constraints of the present invention.

Claims

1. A multi-grade cooling, heating and power coordinated management system for energy hubs, characterized by: include: The high-temperature compressor, the cascade heat storage unit, the first heat exchanger, the low-temperature expander, the cascade cold storage unit, and the second heat exchanger are connected in sequence to form a loop, wherein: during the energy storage process, the high-temperature compressor, the cascade heat storage unit, the heat exchanger, the low-temperature expander, the cascade cold storage unit, the heat exchanger, and the high-temperature compressor are connected in sequence to form a closed loop; during the energy release process, the cascade cold storage unit, the low-temperature compressor, the heat exchanger, the cascade heat storage unit, the high-temperature expander, the heat exchanger, and the cascade cold storage unit are connected in sequence to form a closed loop, and the output end of the high-temperature expander is connected to the generator.

2. The multi-grade cooling, heating and power coordinated management system for energy hubs according to claim 1 is characterized in that: A heat recovery heat exchanger for inputting industrial waste heat, peak-shaving heat energy from coal-fired power plants or solar heat into heat storage devices of corresponding grades and a heat supply heat exchanger for supplying heat energy to the outside are provided between the heat storage devices of the cascade heat storage units.

3. The multi-grade cooling, heating and power coordinated management system for energy hubs according to claim 1 is characterized in that: A cold energy recovery heat exchanger for inputting cold energy from liquefied natural gas vaporization or residual cold from cold chain transportation into the cold storage device of corresponding grade and a cold supply heat exchanger for supplying cold energy to the outside are provided between the cold storage devices of the cascade cold storage unit.

4. The multi-grade cooling, heating and power coordinated management system for energy hubs according to claim 1 is characterized in that: The cascade heat storage unit is composed of multiple heat storage devices connected in series, wherein: each heat storage device is encapsulated with phase change materials with different phase change temperatures, and the phase change temperatures decrease successively along the flow direction of the working medium during the energy storage process.

5. The multi-grade cooling, heating and power coordinated management system for energy hubs according to claim 1 is characterized in that: The cascade cold storage unit is composed of multiple cold storage devices connected in series, wherein: each cold storage device is encapsulated with phase change materials with different phase change temperatures, and the phase change temperatures increase sequentially along the flow direction of the working medium during the energy storage process.

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