RSOC and MCEC combined power generation and energy storage device

Abstract

The utility model discloses an RSOC and MCEC combined power generation and energy storage device, which comprises an RSOC and MCEC combined system, a heat transfer device unit and a self-circulation gas closed-circuit unit, the RSOC and MCEC combined system comprises an SOFC unit, an MCEC unit and an SOEC unit, the heat transfer device unit is used for absorbing heat generated by the operation of the SOFC unit and supplying the heat to the MCEC unit and the SOEC unit for operation, and the self-circulation gas closed-circuit unit is used for supplying heat to the MCEC unit and the SOEC unit for operation. The self-circulation gas closed circuit unit connects the SOFC unit, the MCEC unit and the SOEC unit and is used for forming CH4 decomposition and synthesis to generate chemical energy change; cH4 is used as an energy storage medium, the change of chemical energy in three chemical reaction processes, namely decomposition and synthesis of CH4 and synthesis of hydrogen, and electric energy are associated and converted by using a reversible solid oxide fuel cell system of methane fuel, so that effective storage of the electric energy is realized, and fluctuation of a power grid load is reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to fuel cell energy storage technical field, concretely is a kind of RSOC and MCEC combined power generation energy storage device. BACKGROUND

[0002] The excessive consumption of fossil fuels in the past few centuries has led to an increase in atmospheric carbon dioxide concentration (associated with harmful global warming) and a decrease in available fossil resources. On the other hand, the rapid growth of renewable energy has triggered the need for new efficient technologies that can cope with renewable energy fluctuations and enhance their integration. Converting carbon dioxide into synthetic natural gas compatible with the power grid can help reduce carbon dioxide emissions and dependence on fossil reserves, enabling carbon dioxide to be recovered as a renewable, safe and mature fuel, and stored as surplus renewable energy required for power generation.

[0003] CN216850006U discloses a high-efficiency energy-coupled SOFC power generation device, comprising a heat exchange part, a fuel cell part and a waste heat recovery part connected in series. The reforming gas generated by the heat exchange part is used as fuel gas for the fuel cell. The high-temperature tail gas generated after power generation returns to the heat exchange part to catalytically combust the remaining fuel gas, releasing heat to provide heat for the fuel gas reforming reaction and preheat fresh air. The hot air in the heat exchange part is used as oxidizing gas after the fuel cell generates power. The remaining high-temperature air returns to the heat exchange part to catalytically combust with the remaining fuel gas. The tail gas after catalytic combustion enters the waste heat recovery part to further absorb the heat of the tail gas through cold water.

[0004] CN219297656U discloses a SOFC-SOEC combined system, comprising a fuel supply unit, a control unit, a SOFC unit that generates CO2 using fuel, and a SOEC unit. The control unit is electrically connected to the fuel supply unit, the SOFC unit and the SOEC unit. The fuel supply unit, the SOFC unit and the SOEC unit are connected in series. This solves the problem of CO2 emissions during the combustion of SOFC or other carbon-containing substances, and can also convert CO2 into other carbon-containing compounds with higher chemical energy.

[0005] However, the above-mentioned patents do not solve the problem of difficult storage and transportation of electric energy, and cannot effectively utilize the energy during the reaction process, resulting in low energy utilization efficiency. Therefore, the utility model provides a RSOC and MCEC combined power generation energy storage device to solve the above-mentioned problems. UTILITY MODEL CONTENTS

[0006] The utility model aims to provide a RSOC and MCEC combined power generation energy storage device to solve the problems raised in the background art.

[0007] In order to achieve the above object, the utility model provides the following technical scheme: a RSOC and MCEC combined power storage device, including RSOC and MCEC combined system, heat transfer device unit and self circulating gas closed loop unit, the RSOC and MCEC combined system includes SOFC unit, MCEC unit and SOEC unit,

[0008] The SOFC unit is the O-SOFC limited power generation mode with CH4 as the energy storage medium, the MCEC unit is the limited electrolysis mode with H2 as the energy storage medium, and the SOEC unit is the co-ion SOEC limited electrolysis mode with CH4 as the energy storage medium.

[0009] The heat transfer device unit is used to absorb the heat generated by the operation of the SOFC unit to supply the operation of the MCEC unit and the SOEC unit.

[0010] The self circulating gas closed loop unit connects the SOFC unit, the MCEC unit and the SOEC unit, and is used to form the decomposition and synthesis of CH4 to change chemical energy.

[0011] As a preferred technical scheme, the self circulating gas closed loop unit includes a first container for storing CH4, a second container for storing CO2 and H2O, a third container for storing H2, a fourth container for storing H2O, a fifth container for storing CO2 and a sixth container for storing O2; the first container and the sixth container are connected between the SOFC unit and the SOEC unit to supply CH4 and O2 to the SOFC unit; the second container is connected between the SOFC unit and the MCEC unit to supply CO2 and H2O to the MCEC unit; the third container, the fourth container and the fifth container are connected between the MCEC unit and the SOEC unit to supply H2, H2O and CO2 to the SOEC unit.

[0012] As a preferred technical scheme, the third container and the fourth container are connected with a first separation unit, and the first separation unit is used to separate the product H2 and the unconsumed high-temperature H2O generated by the operation of the MCEC unit.

[0013] As a preferred technical scheme, a second separation unit is arranged between the fifth container and the sixth container, and the second separation unit is used to separate the product H2O and CO2 generated by the operation of the MCEC unit.

[0014] Compared with the prior art, the utility model has the beneficial effects that:

[0015] Using CH4 as the energy storage medium, a reversible solid oxide fuel cell system using methane fuel links and converts the changes in chemical energy during the three chemical reactions of CH4 decomposition and synthesis and hydrogen synthesis with electrical energy, achieving effective electrical energy storage and reducing grid load fluctuations. At the same time, a heat transfer device is used to transfer the heat energy released by the system and to provide heat for the system during heat absorption, realizing heat energy transfer and enabling the system to achieve thermal neutrality, thereby improving the system's energy utilization efficiency. Attached Figure Description

[0016] Figure 1 This is an overall structural diagram of the RSOC and MCEC combined power generation and energy storage device of this utility model;

[0017] Figure 2 yes Figure 1 The operating principle diagram of the SOFC unit;

[0018] Figure 3 yes Figure 1 The operating principle diagram of the MCEC unit;

[0019] Figure 4 yes Figure 1 The operating principle diagram of the SOEC unit;

[0020] Figure 5 yes Figure 1 Working principle diagram of the self-circulating gas closed-loop unit;

[0021] In the diagram: 10, SOFC unit; 20, MCEC unit; 30, SOEC unit; 40, heat transfer device unit; 50, self-circulating gas closed-loop unit; 51, first container; 52, second container; 53, third container; 54, fourth container; 55, fifth container; 56, sixth container; 60, first separation unit; 70, second separation unit. Detailed Implementation

[0022] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0023] Please see Figures 1-5

[0024] The utility model provides a RSOC and MCEC combined power generation energy storage device, aiming at solving the prior art does not aim at solving the problem of difficult electric energy storage and transportation, and cannot effectively utilize the energy in the reaction process, resulting in the defects of low energy utilization efficiency, and the specific implementation is as follows:

[0025] The RSOC and MCEC combined power generation system comprises a SOFC unit 10, an MCEC unit 20 and a SOEC unit 30; the SOFC unit 10 is an O-SOFC limited power generation mode (oxygen ion type solid oxide fuel cell) with CH4 as the energy storage medium, the MCEC unit 20 is a limited electrolysis mode (molten carbonate fuel cell) with H2 as the energy storage medium, the SOEC unit 30 is a co-ionic SOEC limited electrolysis mode (co-ionic solid oxide fuel cell) with CH4 as the energy storage medium, and the power generation and electrolysis are coupled with a heat transfer device to realize heat transfer of the system.

[0026] The self-circulation gas closed loop unit 50 comprises a first container 51 for storing CH4, a second container 52 for storing CO2 and H2O, a third container 53 for storing H2, a fourth container 54 for storing H2O, a fifth container 55 for storing CO2 and a sixth container 56 for storing O2; the first container 51 and the sixth container 56 are connected between the SOFC unit 10 and the SOEC unit 30 to supply CH4 and O2 to the SOFC unit 10; the second container 52 is connected between the SOFC unit 10 and the MCEC unit 20 to supply CO2 and H2O to the MCEC unit 20; the third container 53, the fourth container 54 and the fifth container 55 are connected between the MCEC unit 20 and the SOEC unit 30 to supply H2, H2O and CO2 to the SOEC unit 30.

[0027] In the RSOC and MCEC system, CH4 is used as the energy storage medium, the chemical energy changes in the decomposition and synthesis process of CH4, the chemical energy is linked with the electric energy, and the cycle of storage and release of electric energy is formed to regulate the peak and valley of electric energy. That is to say, the RSOC and MCEC system of the RSOC and MCEC combined power generation energy storage device according to the utility model has the advantages of high energy density, advanced functions of directly and efficiently decomposing and synthesizing CH4, forming the conversion of electric energy-chemical energy-electric energy by utilizing the chemical energy changes in the decomposition and synthesis process of CH4, realizing the cycle of energy storage and release, and regulating the peak and valley of electric energy. It is particularly important to note that, unlike the phase change in the prior art, the utility model utilizes the chemical energy of CH4 by means of the decomposition and synthesis process of CH4 to realize efficient energy storage and release. On this basis, the utility model first proposes the combination of O-SOFC, MCEC and co-ionic SOEC, which can realize efficient conversion, storage and utilization of energy, is helpful to improve the sustainability and flexibility of the energy system, and promotes the development of clean energy technology.

[0028] The heat transfer device unit 40 is used to absorb the heat generated by the operation of the SOFC unit 10 to supply the MCEC unit 20 and the SOEC unit 30 to operate; the SOFC unit 10 releases heat when operating, and the released heat energy is transmitted to the MCEC unit 20 and the SOEC unit 30 through the heat transfer device, and the MCEC unit 20 and the SOEC unit 30 absorb heat when operating, and the heat energy in the heat transfer device is used by them, and the heat absorption and heat release in different modes of power generation and electrolysis are coupled with the heat transfer device to transfer heat energy and redistribute in the working process, so as to realize the heat neutrality of the system. That is, the RSOC and MCEC combined power generation and energy storage device according to the utility model, the heat transfer function of the coupled heat transfer device, the heat release in the power generation mode is used to the heat absorption in the electrolysis mode, so that the heat energy of the system can be efficiently utilized, thereby realizing the heat neutrality of the energy storage system and improving the energy storage efficiency of the system; wherein the heat transfer device unit 40 preferably uses air and water vapor as medium, adopts a water vapor-air heat exchange system, which can be obtained from the existing market.

[0029] During the peak of electricity consumption, the O-SOFC power generation mode is used to make up for the gap in the utilization of electric energy and reduce the pressure of the power grid; during the valley of electricity consumption, the excess electric energy is used in the MCEC electrolysis mode to prepare H2, and the excess electric energy is used in the electrolysis mode of the common ion SOEC to prepare CH4.

[0030] The SOFC unit 10 is stacked by battery sheets, and the battery sheet is composed of an anode, an electrolyte and a cathode, as shown in Figure 2 The CH4 is decomposed into CO2 and H2O by using an electrochemical reaction. The specific operation mode is to introduce CH4 into the anode, introduce O2 into the cathode, and the electrochemical reactions of the following formulas (1) and (2) occur in the electric pile to output electric energy and release heat.

[0031] Cathode of SOFC: 2O2+8e - →4O 2- (1)

[0032] Anode of SOFC: CH4+4O 2- -8e - →CO2+2H2O (2)

[0033] The MCEC unit 20 is composed of an anode, a molten carbonate electrolyte and a cathode, as shown in Figure 3 The CO2 and H2O generated in the O-SOFC are combined into H2 by using an electrochemical reaction. The specific operation mode is to introduce CO2 and H2O into the cathode flow channel, apply a voltage, and the electrochemical reactions of the following formulas (3) and (4) occur in the electric pile to synthesize H2 and absorb heat.

[0034] Cathode of MCEC: 2CO2+2H2O+4e -→ 2CO3 2- + 2H2 (3)

[0035] Anode of MCEC: 2CO3 2- - 4e - → 2CO2+ O2 (4)

[0036] SOEC unit 30 is stacked by battery pieces, which are composed of anode, electrolyte and cathode, as shown in Figure 4 CO2 and H2 are synthesized into CH4 by electrochemical reaction. The specific operation mode is to pass H2O into the anode and CO2 and H2 into the cathode, and the electrochemical reactions of the following formula (5) and (6) occur in the stack to synthesize CH4 and absorb heat.

[0037] Cathode of co-ion SOEC: 2CO2+ 2H2+ 4H + + 8e - → 2CH4+ 4O 2- (5)

[0038] Anode of co-ion SOEC: 2H2O- 8e - + 4O 2- → 4H + + 3O2 (6)

[0039] As shown in Figure 5 , CH4 and O2 produced by SOEC unit 30 are stored in first container 51 and sixth container 56 respectively for SOFC unit 10 to use, CO2 and H2O produced by SOFC unit 10 are stored in second container 52 for MCEC to use, H2 and unspent high-temperature H2O are separated by first separation unit 60, which is a device such as a radiator that can absorb the heat of high-temperature H2O, so that the heat of high-temperature H2O can be used for heating, and high-temperature H2O is converted into liquid, H2 and H2O are separated, and stored in third container 53 and fourth container 54 respectively for SOEC unit 30 to use;

[0040] At the same time, CO2 and O2 produced by MCEC unit 20 are separated by first separation unit 70, CO2 is stored in fifth container 55, and O2 is stored in sixth container 56 for SOEC unit 30 to complete the synthesis of CH4, first separation unit 70 is a molecular sieve, which adsorbs CO2 to separate O2, after separation, by heating the molecular sieve, CO2 molecules adsorbed on the surface channels of the molecular sieve are desorbed, thereby entering the sixth container 56 for storage.

[0041] In particular, the gas utilization mode in the RSOC and MCEC combined power generation and energy storage device is feeding and product recycling, the gas system is a closed system, therefore, after initial operation, no gas needs to be provided to the system, no material exchange with the environment atmosphere, no gas leakage risk, high safety performance.

[0042] Although the embodiments of the present application have been shown and described, it is to be understood that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present application, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A combined RSOC and MCEC power generation and energy storage device, characterized by, The system comprises a RSOC and MCEC combined system, a heat transfer device unit and a self-circulation gas closed loop unit, the RSOC and MCEC combined system comprises a SOFC unit, a MCEC unit and a SOEC unit; The SOFC unit is an O-SOFC limited power generation mode with CH4 as the energy storage medium, the MCEC unit is a limited electrolysis mode with H2 as the energy storage medium, and the SOEC unit is a co-ionic SOEC limited electrolysis mode with CH4 as the energy storage medium; The heat transfer device unit is used to absorb the heat generated by the operation of the SOFC unit to supply the operation of the MCEC unit and the SOEC unit; The self-circulation gas closed loop unit connects the SOFC unit, the MCEC unit and the SOEC unit to form the chemical energy change of CH4 decomposition and synthesis.

2. The RSOC and MCEC combined power generation and energy storage device of claim 1, wherein, The self-circulation gas closed loop unit comprises a first container for storing CH4, a second container for storing CO2 and H2O, a third container for storing H2, a fourth container for storing H2O, a fifth container for storing CO2 and a sixth container for storing O2; The first container and the sixth container are connected between the SOFC unit and the SOEC unit to supply CH4 and O2 to the SOFC unit; The second container is connected between the SOFC unit and the MCEC unit to supply CO2 and H2O to the MCEC unit; The third container, the fourth container and the fifth container are connected between the MCEC unit and the SOEC unit to supply H2, H2O and CO2 to the SOEC unit.

3. The RSOC and MCEC combined power generation and energy storage device of claim 2, wherein, The third container and the fourth container are connected with a first separation unit, and the first separation unit is used to separate the product H2 and the unused high-temperature H2O generated by the operation of the MCEC unit.

4. The RSOC and MCEC combined power generation and energy storage device of claim 3, wherein, A second separation unit is arranged between the fifth container and the sixth container, and the second separation unit is used to separate the product H2O and CO2 generated by the operation of the MCEC unit.

Images