CN117294027B - Energy storage system - Google Patents

Abstract

The invention relates to an energy storage system, which comprises a liquid storage tank, an energy release module, an air storage warehouse and an energy storage module which are sequentially connected in a closed loop, wherein the energy storage system also comprises a coal-to-methanol component, and the energy storage system comprises the following components: the coal-to-methanol component comprises a flash tower and an acid gas removal unit, wherein the flash tower is connected with the energy storage module and/or the energy release module and is used for generating and providing a heat source, and the acid gas removal unit is connected with the gas storage and is used for generating and providing high-purity carbon dioxide so as to effectively recycle the carbon dioxide in the working process of the coal-to-methanol component; the heat source generated by the flash tower can provide heat required by the processes of preheating, evaporating, heating and the like in the energy storage stage and/or the energy release stage so as to effectively utilize the waste heat in the working process of the coal-to-methanol component; therefore, the energy utilization rate is improved and the production cost is saved by coupling the technological process of the coal-to-methanol component in the energy storage stage and the energy release stage.

Description

energy storage system

Technical field

The present invention relates to the technical field of energy storage, and in particular to an energy storage system.

Background technique

At present, energy storage technology based on the carbon dioxide gas-liquid phase change cycle compresses and condenses the gaseous carbon dioxide at normal temperature and pressure in the gas storage into liquid carbon dioxide and stores it in a liquid storage tank during the low period of electricity consumption, and uses thermal energy to heat it during the peak period of electricity consumption. The liquid carbon dioxide turns into a gaseous state, and the gaseous carbon dioxide drives the turbine to drive the generator to generate electricity, and the gaseous carbon dioxide after doing the work is returned to the gas storage for recycling. It is a gas that does not depend on geological conditions, has a long life, high reliability and low cost. The liquid-to-liquid two-state collaborative energy storage technology can be used to support grid peak shaving and valley filling, frequency modulation, phase modulation, and provide backup power for the grid. The current large-scale development of coal-to-methanol produces a large amount of carbon dioxide, and the economic benefits of using this carbon dioxide are low. Moreover, the low-temperature waste heat generated in the coal-to-methanol process is difficult to reuse in industrial production due to its low temperature.

Therefore, providing a cost-saving energy storage system is an urgent technical problem that needs to be solved.

Contents of the invention

Based on this, it is necessary to provide an energy storage system to address the above technical problems, by coupling the process of industrial methanol production into the energy storage and energy release process, so as to utilize the waste heat of industrial methanol production and carbon dioxide during the energy storage and energy release process. , improve energy utilization and save production costs.

The invention provides an energy storage system, which includes a liquid storage tank, an energy release module, a gas storage and an energy storage module connected in a closed loop in sequence. The energy storage system also includes a coal-to-methanol component, wherein:

The coal-to-methanol component includes a flash evaporation tower and an acid gas removal unit. The flash evaporation tower is connected to the energy storage module and/or the energy release module and is used to generate and provide a heat source. The acid gas removal unit The gas removal unit is connected to the gas storage and is used to generate and provide high-purity carbon dioxide.

When the above energy storage system is working, the coal-to-methanol component is started, the flash tower generates a heat source, the acid gas removal unit generates high-purity carbon dioxide at normal temperature and pressure, and the high-purity carbon dioxide at normal temperature and pressure is replenished into the gas storage to effectively Recover the carbon dioxide during the working process of the coal-to-methanol component, and use the recovered carbon dioxide in the energy storage and energy release cycle; in the energy storage stage, the carbon dioxide at normal temperature and pressure stored in the gas storage enters the energy storage module, and is used in the valley power During the energy-driven energy storage module, the carbon dioxide at normal temperature and pressure is converted into high-pressure liquid carbon dioxide. The high-pressure liquid carbon dioxide is stored in the liquid storage tank; during the energy release stage, the high-pressure liquid carbon dioxide stored in the liquid storage tank enters the energy release module. Inside, the energy release module first converts high-pressure liquid carbon dioxide into high-temperature and high-pressure carbon dioxide. The high-temperature and high-pressure carbon dioxide expands and converts into normal temperature and normal pressure carbon dioxide. The normal temperature and normal pressure carbon dioxide flows back and is stored in the gas storage; flash evaporation tower The generated heat source can provide the heat required for preheating, evaporation, heating and other processes during the energy storage stage and/or energy release stage, so as to effectively utilize the waste heat during the operation of the coal-to-methanol component; therefore, the above energy storage system By coupling the process of coal-to-methanol components in the energy storage stage and energy release stage, energy utilization is improved and production costs are saved.

In one embodiment, the energy release module includes an evaporator, and the evaporator is connected to the flash tower.

In one embodiment, the energy storage module further includes a preheater, and the preheater is connected to the flash tower.

In one embodiment, the coal-to-methanol component further includes a cryogenic unit, which is connected to the energy storage module and/or the energy release module and is used to generate and provide a cold source.

In one embodiment, the energy storage module includes a condenser, and the cryogenic unit is connected to the condenser and used to provide a cold source to the condenser.

In one embodiment, the energy release module includes a regenerator, and the cryogenic unit is connected to the regenerator and is used to provide a cold source to the regenerator.

In one embodiment, the acid gas removal unit includes a carbon dioxide desorption tower, which is used to remove impurities other than carbon dioxide to form high-purity carbon dioxide.

In one embodiment, the energy release module further includes a heater, a turbine and a generator, and the heater and the turbine are connected in sequence between the liquid storage tank and the gas storage tank, so The turbine is also connected to the generator, and is used to utilize the gaseous carbon dioxide from the heater to perform expansion work. The generator is electrically connected to the coal-to-methanol assembly, and is used to operate when the gaseous carbon dioxide is used by the turbine. When driven by the expansion work, electricity is generated and the electricity is input to the coal-to-methanol assembly.

In one embodiment, the coal-to-methanol component also includes an air separation unit and a pressurized gasification unit. The air separation unit is used to extract oxygen from the air. The pressurized gasification unit is connected with the air separation unit. The unit and the flash tower are connected, and are used to thermally process coal to form crude synthesis gas that is sent to the flash tower. The flash tower is used to recover the pressurized gasification unit during the flash evaporation process. , the heat of the crude synthesis gas.

In one embodiment, the flash tower includes a low-pressure black water flash tower and/or a syngas flash tower.

Description of the drawings

Figure 1 is a schematic structural diagram of the energy storage system in the first embodiment of the present invention;

Figure 2 is a schematic structural diagram of the energy storage system in the second embodiment of the present invention;

Figure 3 is a schematic structural diagram of the energy storage system in the third embodiment of the present invention;

Figure 4 is a schematic structural diagram of the energy storage system in the fourth embodiment of the present invention;

Figure 5 is a schematic structural diagram of the energy storage system in the fifth embodiment of the present invention;

Figure 6 is a schematic structural diagram of the energy storage system in the sixth embodiment of the present invention;

Figure 7 is a schematic structural diagram of the energy storage system in the seventh embodiment of the present invention.

Reference signs:

10. Energy storage system;

100. Liquid storage tank;

200. Energy release module; 210. Evaporator; 220. Heater; 230. Turbine; 240. Generator; 250. Regenerator;

300. Gas storage;

400. Energy storage module; 410. Condenser; 420. Compressor; 430. Preheater; 440. Cooler;

500. Coal-to-methanol component; 510. Flash evaporation tower; 520. Acid gas removal unit; 521. Carbon dioxide analysis tower; 530. Cryogenic unit; 540. Air separation unit; 550. Pressurized gasification unit;

600. Methanol;

700. Heat source;

800. Carbon dioxide;

900. Cold source;

20. Coal-containing working fluids.

Detailed ways

In order to make the above objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, the present invention can be implemented in many other ways different from those described here. Those skilled in the art can make similar improvements without departing from the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

In the description of the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", " "Back", "Left", "Right", "Vertical", "Horizontal", "Top", "Bottom", "Inside", "Outside", "Clockwise", "Counterclockwise", "Axis" The orientations or positional relationships indicated by "radial direction", "circumferential direction", etc. are based on the orientations or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply the device or device referred to. Elements must have a specific orientation, be constructed and operate in a specific orientation and therefore are not to be construed as limitations of the invention.

In addition, the terms “first” and “second” are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of indicated technical features. Therefore, features defined as "first" and "second" may explicitly or implicitly include at least one of these features. In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise expressly and specifically limited.

In the present invention, unless otherwise clearly stated and limited, the terms "installation", "connection", "connection", "fixing" and other terms should be understood in a broad sense. For example, it can be a fixed connection or a detachable connection. , or integrated into one; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be an internal connection between two elements or an interactive relationship between two elements, unless otherwise specified restrictions. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

In the present invention, unless otherwise expressly stated and limited, a first feature being "on" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. touch. Furthermore, the terms "above", "above" and "above" the first feature is above the second feature may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is higher in level than the second feature. "Below", "below" and "beneath" the first feature to the second feature may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature has a smaller horizontal height than the second feature.

It should be noted that when an element is referred to as being "mounted" or "disposed on" another element, it can be directly on the other element or intervening elements may also be present. When an element is said to be "connected" to another element, it can be directly connected to the other element or there may also be intervening elements present. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are for illustrative purposes only and do not represent the only implementation manner.

The technical solutions provided by the embodiments of the present invention will be introduced below with reference to the accompanying drawings.

Existing technology, such as the existing patent CN112985145A, an energy storage system based on carbon dioxide gas-liquid phase change cycle for energy storage includes a liquid storage tank, an energy release module, a gas storage and an energy storage module. Among them, the liquid storage tank and the energy release module , gas storage and energy storage modules are connected in a closed loop through pipelines. As a gaseous carbon dioxide storage device, the gas storage module is used to store carbon dioxide at normal temperature and pressure; the energy storage module is used as an energy conversion component to convert the normal temperature and normal pressure carbon dioxide flowing out of the gas storage into high-pressure liquid carbon dioxide. During the conversion process, electrical energy is converted into pressure energy and thermal energy to achieve energy storage; the liquid storage tank is used as a liquid carbon dioxide storage device to store high-pressure liquid carbon dioxide; the energy release module is used as an energy conversion component to convert The high-pressure liquid carbon dioxide flowing out of the liquid storage tank is converted into carbon dioxide at normal temperature and pressure. During the conversion process, thermal energy and pressure energy are converted into electrical energy, and the stored energy is released and utilized.

As shown in Figures 1, 2 and 3, the present invention improves the energy storage system in the prior art. The improved energy storage system 10 consists of the original liquid storage tank 100, energy release module 200, gas storage 300 and On the basis of the energy storage module 400, a coal-to-methanol component 500 is added. The coal-to-methanol component 500 is used to generate methanol 600 from coal. During the generation of methanol 600, carbon dioxide 800 and waste heat are produced. The energy storage system 10 provided by the present invention deeply couples the carbon dioxide gas-liquid phase change cycle and industrial methanol production to realize energy storage and methanol production at the same time, so as to utilize the concomitant production of methanol during the energy storage process. 800% of carbon dioxide and waste heat, improving energy utilization and saving production costs. Since the specific structures of the liquid storage tank 100, the energy release module 200, the gas storage 300 and the energy storage module 400 have not been improved, existing structures can be used, such as the liquid storage tank in the existing patent CN112985145A (the liquid storage tank of the present invention). tank 100), energy release component (energy release module 200 of the present invention), gas storage (gas storage 300 of the present invention) and energy storage component (energy storage module 400 of the present invention).

As shown in FIG. 4 , the energy storage module 400 includes a condenser 410 , a compressor 420 , a preheater 430 , and a cooler 440 . From the gas storage tank 300 toward the liquid storage tank 100, a preheater 430, a compressor 420, a cooler 440 and a condenser 410 are arranged in sequence and are connected as a whole through pipelines. The preheater 430 is used to heat the carbon dioxide 800 at normal temperature and pressure input from the gas storage 300 , the compressor 420 is used to compress the carbon dioxide 800 during the energy storage process, and the cooler 440 is used to compress the compressed carbon dioxide 800 To cool down, the condenser 410 is used to condense carbon dioxide 800 during the energy storage process.

The energy release module 200 includes an evaporator 210, a heater 220, a turbine 230, a generator 240, and a regenerator 250. From the liquid storage tank 100 toward the gas storage 300, the evaporator 210, the heater 220, and the turbine 230 , regenerator 250 are arranged in sequence and connected as a whole through pipelines. The evaporator 210 is used to evaporate the high-pressure liquid carbon dioxide 800 during the energy release process, the heater 220 is used to exchange heat and raise the temperature of the evaporated carbon dioxide 800, and the turbine 230 is used to utilize the high-temperature and high-pressure carbon dioxide 800 to expand and perform work. The generator 240 is connected to the turbine 230 and is used to generate electricity when driven by the expansion work of the turbine 230. The regenerator 250 is used to cool down the carbon dioxide 800 during the energy release process.

In the energy storage system 10 provided by the present invention, as shown in Figure 4, the coal-to-methanol component 500 includes a flash evaporation tower 510. The flash evaporation tower 510 is used to recover the heat in the methanol preparation process through the flash evaporation process, and convert these Heat generating heat source 700. In specific settings, the heat source 700 may be hot steam, hot water, etc. The flash tower is a kind of chemical equipment that realizes the gas-liquid phase separation of materials in the chemical production process. It is used to convert high-pressure saturated liquid into low-pressure saturated steam and saturated liquid. According to the different materials processed in the chemical production process, it can be divided into low-pressure black water flash evaporation tower and syngas flash evaporation tower. The low-pressure black water flash evaporation tower flashes the black water generated in the chemical industry process into steam, and uses steam and In the form of hot water, as the heat source 700, the syngas flash evaporation tower flashes the water gas generated in the chemical process into synthesis gas, and the hot steam formed by the synthesis gas is used as the heat source 700. For the coal-to-methanol assembly 500 of the present invention, the flash tower 510 can be a low-pressure black water flash tower, a syngas flash tower, or a combination of a low-pressure black water flash tower and a syngas flash tower, Other structural forms that can meet the requirements are also possible.

There are three ways to set up the flash tower 510: Mode 1, as shown in Figure 1, the flash tower 510 is connected to the energy storage module 400 through pipelines, and the flash tower 510 is used to provide the heat source 700 to the energy storage module 400; Method two, as shown in Figure 2, the flash evaporation tower 510 and the energy release module 200 are connected through pipelines, and the flash evaporation tower 510 is used to provide the heat source 700 to the energy release module 200; Method three, as shown in Figure 3, the flash evaporation tower 510 is connected to the energy storage module 400 and the energy release module 200 through pipelines respectively, and the flash tower 510 provides the heat source 700 to the energy storage module 400 and the energy release module 200 respectively.

In the energy storage system 10 provided by the present invention, as shown in Figure 4, the coal-to-methanol component 500 also includes an acid gas removal unit 520. The acid gas removal unit 520 is used to remove gases generated during the methanol preparation process. Remove acidic components such as hydrogen sulfide and carbon dioxide to form high-purity carbon dioxide 800. In specific settings, the acid gas removal unit is a waste gas treatment equipment specially used to treat acidic gases. According to the different treatment methods during the treatment process, it can be divided into acid gas absorption tower, carbon dioxide analysis tower, and carbon dioxide stripping tower. , the acid gas absorption tower is used to absorb acid gases other than carbon dioxide, the carbon dioxide desorption tower is used to reduce pressure and analyze carbon dioxide, and the carbon dioxide stripping tower is used to extract carbon dioxide from syngas. Regarding the coal-to-methanol assembly 500 of the present invention, the acid gas removal unit 520 can be one of the three acid gas absorption towers, carbon dioxide analysis towers, and carbon dioxide stripping towers, or can also be an acid gas absorption tower, a carbon dioxide analysis tower, or a carbon dioxide stripping tower. Of course, the combination of the three stripping towers can also be in other structural forms that can meet the requirements. The acid gas removal unit 520 is connected to the gas storage 300 through pipelines, and the acid gas removal unit 520 is used to provide high-purity carbon dioxide 800 to the gas storage 300 .

When the above energy storage system 10 is working, the coal-to-methanol component 500 is started, the flash tower 510 generates the heat source 700, the acid gas removal unit 520 generates high-purity carbon dioxide 800 at normal temperature and pressure, and the high-purity carbon dioxide 800 at normal temperature and pressure is replenished to the storage. In the gas storage 300, the carbon dioxide 800 during the working process of the coal-to-methanol component 500 can be effectively recovered, and the recovered carbon dioxide 800 is used in the energy storage and energy release cycle; in the energy storage stage, the normal temperature and normal temperature stored in the gas storage 300 Carbon dioxide 800 at a high pressure (temperature in the range of -40 to 70°C, and the difference between the pressure and the external atmosphere is less than 1000 Pa, for example) enters the energy storage module 400. During the off-peak period, the electricity-driven energy storage module 400 converts carbon dioxide 800 at normal temperature and pressure. into high-pressure liquid carbon dioxide 800 (temperature between 20°C and 30°C, pressure between 4MPa and 7.5MPa). The high-pressure liquid carbon dioxide 800 is stored in the liquid storage tank 100; in the energy release stage, the carbon dioxide 800 stored in the liquid storage tank 100 The high-pressure liquid carbon dioxide 800 enters the energy release module 200. The energy release module 200 first converts the high-pressure liquid carbon dioxide 800 into high-temperature and high-pressure carbon dioxide 800 (the temperature reaches above 150°C and the pressure is between 4MPa and 7.5MPa). The carbon dioxide 800 expands and performs work and is converted into carbon dioxide 800 at normal temperature and pressure. The carbon dioxide 800 at normal temperature and pressure is refluxed and stored in the gas storage 300; the heat source 700 generated by the flash tower 510 can be used in the energy storage stage and/or energy release. stage to provide the heat required for preheating, evaporation, heating and other processes, so as to effectively utilize the waste heat during the working process of the coal-to-methanol component 500; therefore, the above-mentioned energy storage system 10 couples the coal-to-methanol production process in the energy storage stage and energy release stage. The process of the methanol component 500 improves energy utilization and saves production costs.

In addition to providing a heat source 700 and carbon dioxide 800, the coal-to-methanol assembly 500 also generates other accompanying products. In a preferred embodiment, as shown in Figures 4, 5, 6 and 7, the coal-to-methanol assembly 500 It also includes a cryogenic unit 530. The cryogenic unit 530 mechanically cools the gas generated during the methanol preparation process, and uses different boiling points to separate the methanol 600. At the same time, a small amount of low-temperature residual cold can be formed. This part of the low-temperature residual cold Used as a cold source 900. The cryogenic unit 530 is connected to the energy storage module 400 and/or the energy release module 200 , and is used to provide the cold source 900 to the energy storage module 400 and/or the energy release module 200 . In specific settings, the cold source 900 is cold water. The cryogenic unit is a device that can generate residual cooling during the synthesis gas separation process. In the coal-to-methanol component 500 of this application, the cryogenic unit 530 can be a low-temperature distillation tower, or other structural forms that can meet the requirements. .

Specifically, the coal-to-methanol assembly 500 provides the cooling capacity required by the condenser 410 during the condensation process. The cryogenic unit 530 and the condenser 410 are connected through pipelines, and the cryogenic unit 530 provides the cold source 900 to the condenser 410 . In specific settings, the condenser 410 is installed at the entrance of the liquid storage tank 100. During the off-peak period, the electric-driven compressor 420 compresses the carbon dioxide 800. After the carbon dioxide 800 is pressurized, it enters the condenser 410 for condensation. The condensed carbon dioxide 800 is converted into It is stored in the liquid storage tank 100 in a high-pressure liquid state.

Specifically, the coal-to-methanol assembly 500 provides the cooling capacity required by the regenerator 250 during the cooling process. The cryogenic unit 530 and the regenerator 250 are connected through pipelines, and the cryogenic unit 530 provides the cold source 900 to the regenerator 250 . In specific settings, the regenerator 250 is installed at the entrance of the gas storage 300 . The expanded carbon dioxide 800 enters the regenerator 250 for cooling, and the cooled carbon dioxide 800 is stored in the gas storage 300 .

When the above energy storage system 10 is working, the cryogenic unit 530 generates a cold source 900, which enters the condenser 410 and the regenerator 250. During the energy storage stage, carbon dioxide 800 at normal temperature and pressure is stored in the gas storage 300. Entering the energy storage module 400, the compressor 420 compresses the carbon dioxide 800. The pressurized carbon dioxide 800 performs heat exchange with the cold source 900 in the condenser 410 for cooling, and the carbon dioxide 800 converted into high-pressure liquid is stored in the liquid storage tank 100. . In the energy release stage, the high-pressure liquid carbon dioxide 800 stored in the liquid storage tank 100 enters the energy release module 200. It is first converted into high-temperature and high-pressure carbon dioxide 800, and after expansion and work, it is converted into high-temperature and normal-pressure carbon dioxide 800, and finally enters The temperature is cooled in the regenerator 250 , and the cooled carbon dioxide 800 is stored in the gas storage 300 . The cold source 900 generated by the cryogenic unit 530 can quickly realize the gas-liquid phase change of the carbon dioxide 800, improve the cycle efficiency of the energy storage system 10, effectively utilize the residual cold during the working process of the coal-to-methanol component 500, and improve the energy Utilization.

The heat source 700 can come from various sources. In a preferred embodiment, the heat source 700 comes from the waste heat of the flash gas formed by the flash tower 510 . In specific settings, flash gas is formed in the flash tower 510 during the industrial process of producing methanol 600. The flash tower 510 recovers the formed flash gas, and collects and processes the waste heat in the recovered flash gas to form the heat source 700. . Of course, the heat source 700 is not limited to the above-mentioned flash gas waste heat, and may also include other remaining low-quality waste heat in the factory where the energy storage system 10 is located, or the steam waste heat in the industrial process of producing methanol 600.

When the above energy storage system 10 is working, since the output of flash steam waste heat formed by the flash evaporation tower 510 is relatively large, using the flash steam waste heat formed by the flash evaporation tower 510 as the heat source 700 can provide a relatively stable heat source and avoid A large amount of heat is wasted and energy utilization efficiency is improved.

In order to facilitate the flash evaporation tower 510 to provide the heat source 700 to the energy release module 200, specifically, as shown in Figure 4, the evaporator 210 and the flash evaporation tower 510 are connected through pipelines, the evaporator 210 is used to receive the waste heat of the flash gas, and the evaporator 210 uses the waste heat of the flash gas to evaporate the high-pressure liquid carbon dioxide 800 during the energy release process. During the specific setting, during the energy release stage, the carbon dioxide 800 evaporates through the evaporator 210 and then enters the heater 220 for heat exchange and temperature rise. The high-temperature and high-pressure carbon dioxide 800 enters the turbine 230 to expand and perform work, and the carbon dioxide 800 that has performed work enters Gas storage 300.

When the above energy storage system 10 is working, the waste heat of the flash gas in the flash tower 510 enters the evaporator 210, and serves as the heat source 700 in the evaporator 210. The high-pressure liquid carbon dioxide 800 stored in the liquid storage tank 100 enters the evaporator. 210, and conducts heat exchange with the heat source 700 in the evaporator 210 to increase the temperature and convert it into high temperature and high pressure carbon dioxide 800, so that the waste heat of the flash steam can be effectively utilized in the energy release module 200.

In order to facilitate the flash tower 510 to provide the heat source 700 to the energy storage module 400, specifically, as shown in Figure 4, the preheater 430 is connected to the flash tower 510 through a pipeline, and the preheater 430 is used to receive the waste heat of the flash gas, and The preheater 430 is used to preheat the carbon dioxide 800 at normal temperature and pressure by using the waste heat of flash steam during the energy storage process. In specific settings, during the energy storage stage, carbon dioxide 800 at normal temperature and pressure enters the compressor 420 after being heated up by the preheater 430. The compressor 420 compresses the carbon dioxide 800, and the formed high-temperature and high-pressure carbon dioxide 800 enters the cooler 440, and is The cooler 440 cools down to high-pressure and low-temperature carbon dioxide 800. The high-pressure and low-temperature carbon dioxide 800 enters the condenser 410 for condensation, and is converted into high-pressure liquid carbon dioxide 800 after condensation.

When the above energy storage system 10 is working, the residual heat of the flash gas in the flash tower 510 enters the preheater 430, and serves as the heat source 700 in the preheater 430. The carbon dioxide 800 stored in the gas storage 300 at normal temperature and pressure enters. into the preheater 430, and conducts heat exchange with the heat source 700 in the preheater 430 to increase the temperature, and converts it into high temperature and normal pressure carbon dioxide 800, so that the waste heat of the flash gas can be effectively utilized in the energy release module 200.

In order to improve the purity of carbon dioxide 800, in a preferred embodiment, as shown in Figure 4, the acid gas removal unit 520 includes a carbon dioxide desorption tower 521. The carbon dioxide desorption tower 521 is used to process the methanol solution rich in carbon dioxide 800, from which Carbon dioxide 800 is separated and impurities other than carbon dioxide 800 are removed to form high-purity carbon dioxide 800. When the above-mentioned energy storage system 10 is working, since the purity of the carbon dioxide 800 formed by the acid gas removal unit 520 is relatively high, the high-purity carbon dioxide 800 is stored in the gas storage 300 and serves as the energy storage stage and the energy release stage. working fluid, so that the operation stability, cycle efficiency and reliability of the entire energy storage system 10 are higher.

In order to further improve energy utilization, in a preferred embodiment, as shown in FIG. 4 , the generator 240 is connected to the coal-to-methanol assembly 500 , and the electricity generated by the generator 240 is used as the electrical energy of the coal-to-methanol assembly 500 . During specific work, after the carbon dioxide 800 evaporates through the evaporator 210, it enters the heater 220 for heat exchange and temperature rise. The high-temperature and high-pressure carbon dioxide 800 enters the turbine 230 to expand and do work. The expansion of the turbine 230 drives the generator 240 to perform work. After generating electricity, the carbon dioxide 800 enters the gas storage 300. Part of the electricity produced by the generator 240 can be connected to the power grid, and the other part can be used as the electric energy required in the process of preparing methanol by the coal-to-methanol component 500 to further improve energy utilization. efficiency, saving production costs.

In order to facilitate the work of the flash evaporation tower 510, more specifically, as shown in Figure 4, the coal-to-methanol assembly 500 also includes an air separation unit 540 and a pressurized gasification unit 550. The air separation unit 540 is used to remove oxygen and oxygen in the air. Nitrogen is separated to extract oxygen from the air and used as a working fluid in the subsequent methanol production process. The pressurized gasification unit 550 is connected to the air separation unit 540 and the flash tower 510 through pipelines. The pressurized gasification unit 550 is used to thermally process coal or coke oven gas and other coal-containing working fluids 20 with oxygen to form The crude syngas is transported to the flash tower 510. The crude syngas contains acidic components such as hydrogen sulfide, carbon dioxide, and high-temperature black water. When the above energy storage system 10 is working, the air separation unit 540 uses air to form oxygen, and the pressurized gasification unit 550 uses oxygen and coal-containing working fluid 20 to generate rough syngas. After the rough syngas is transported to the flash tower 510, it is flashed The process recovers the heat contained in the black water discharged from the gasifier and the scrubber to generate the heat source 700 .

The technical features of the above embodiments can be combined in any way. To simplify the description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, all possible combinations should be used. It is considered to be within the scope of this manual.

The above embodiments only express several embodiments of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention. It should be noted that, for those of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the scope of protection of the patent of the present invention should be determined by the appended claims.

Claims (4)

1. An energy storage system, characterized in that it includes a liquid storage tank, an energy release module, a gas storage and an energy storage module connected in a closed loop in sequence. The energy storage system also includes a coal-to-methanol component, and the coal-to-methanol component The component is used to generate methanol from coal, and during the methanol generation process, low-temperature waste heat and gas containing carbon dioxide are produced, wherein: The coal-to-methanol component includes a flash evaporation tower and an acid gas removal unit. The flash evaporation tower is connected to the energy storage module and/or the energy release module, and is used to use the low-temperature waste heat to generate and provide A heat source, the acid gas removal unit is connected to the gas storage, and is used to generate and provide high-purity carbon dioxide using the gas containing carbon dioxide; The energy release module includes an evaporator, and the evaporator is connected to the flash evaporation tower; The energy storage module includes a preheater, and the preheater is connected to the flash tower; The coal-to-methanol assembly also includes a cryogenic unit, which is connected to the energy storage module and/or the energy release module and is used to generate and provide a cold source; The energy storage module includes a condenser, and the cryogenic unit is connected to the condenser and used to provide a cold source to the condenser; The energy release module includes a regenerator, and the cryogenic unit is connected to the regenerator and used to provide a cold source to the regenerator; The coal-to-methanol component also includes an air separation unit and a pressurized gasification unit. The air separation unit is used to extract oxygen from the air. The pressurized gasification unit is connected with the air separation unit and the flash tower. Connected, used to thermally process coal to form crude synthesis gas that is sent to the flash evaporation tower. The flash evaporation tower is used to recover the pressurized gasification unit and the crude synthesis gas during the flash evaporation process. heat. 2. The energy storage system according to claim 1, characterized in that the acid gas removal unit includes a carbon dioxide analysis tower, and the carbon dioxide analysis tower is used to remove impurities other than carbon dioxide to form high-purity carbon dioxide. 3. The energy storage system according to claim 1, wherein the energy release module further includes a heater, a turbine and a generator, and the heater and the turbine are connected to the liquid storage tank in sequence. Between the gas storage and the gas storage, the turbine is also connected to the generator, and is used to utilize the gaseous carbon dioxide from the heater to perform expansion. The generator is electrically connected to the coal-to-methanol component. Connection for generating electric power when driven by the expansion work of the turbine and inputting the electric power to the coal-to-methanol assembly. 4. The energy storage system according to claim 1, wherein the flash tower includes a low-pressure black water flash tower and/or a syngas flash tower.