CN108301924A - Mixing energy supplying system based on gas turbine and solid oxide fuel cell - Google Patents

Abstract

The invention relates to a hybrid energy supply system based on a gas turbine and a solid oxide fuel cell, and belongs to the field of distributed energy supply systems. The system includes solid oxide fuel cells, combustion chambers, VM cycle heat pumps and other components. H ₂ and O ₂ react in the solid oxide fuel cell to generate electricity; at the same time, the gas fuel mainly CH ₄ undergoes oxygen-enriched combustion in the combustion chamber, and the high-temperature gas generated enters the gas turbine to expand and do work, so that the generator generates electricity; The gas turbine flue gas is used to drive the VM cycle heat pump to supply cooling to users in summer, heat to users in winter, and provide users with domestic hot water load throughout the year. The hybrid energy supply system can not only ensure the system's demand for electricity, cooling and heating energy, but also make full use of energy.

Description

Hybrid energy supply system based on gas turbine and solid oxide fuel cell

technical field

The invention belongs to the field of distributed energy supply systems, in particular to a hybrid energy supply system based on gas turbines and solid oxide fuel cells.

Background technique

Among all fuel cells, solid oxide fuel cells have the highest operating temperature and are high-temperature fuel cells. In recent years, due to the advantages of low cost and high maintainability, distributed power plants have gradually become an important part of the world's energy supply, and the combined power generation system composed of solid oxide fuel cells, gas turbines, and steam turbines not only has high power generation efficiency ( Up to 70%), also has low pollution environmental benefits, very suitable for distributed power generation.

However, the exhaust gas temperature of the combined power generation system composed of solid oxide fuel cells, gas turbines, and steam turbines is about 800°C, and the direct discharge will cause a great waste of energy.

In order to realize the cascade utilization of exhaust heat, the VM cycle heat pump is selected as the cold and heat production equipment. The heat source of the VM cycle heat pump can be traditional fossil energy, or new energy such as solar energy and biomass energy. Cooperating with the development of new energy is of great significance for energy saving and emission reduction. Compared with other heating/cooling equipment, the VM cycle heat pump It has obvious socio-economic and environmental advantages.

Contents of the invention

In view of the above existing problems and phenomena, the present invention provides a hybrid energy supply system based on a gas turbine and a solid oxide fuel cell, aiming at improving the operating efficiency of the system through a parallel system and realizing cascaded utilization of energy.

In order to achieve the above object, the technical scheme that the present invention takes is:

A hybrid energy supply system based on gas turbines and solid oxide fuel cells, including:

Compressor: configured to compress air;

air separator: configured to separate air;

fuel preheater: configured to heat fuel;

Gas preheater: configured to heat _O2 ;

Reformer: configured to reform the preheated fuel to produce hydrogen for the solid oxide fuel cell anode;

Solid Oxide Fuel Cells: configured to produce electrical energy through an electrochemical reaction;

Combustion chamber: configured for oxygen-enriched combustion to produce high-temperature gases;

Gas turbines: configured to convert thermal energy of high temperature gases into mechanical energy;

Generator: configured to convert mechanical energy into electrical energy;

VM cycle heat pump: It is configured to transfer the low-temperature heat source of steam to the high-temperature heat source for cooling and heating to meet the energy demand of users;

Heat exchanger I: it is configured to transfer the heat of the hot fluid in the heat chamber of the VM cycle heat pump to the cold fluid;

Heat exchanger II: It is configured to transfer the heat of the hot fluid in the chamber of the VM cycle heat pump to the cold fluid;

Heat exchanger III: It is configured to transfer the cooling capacity of the cold fluid in the cold chamber of the VM cycle heat pump to the hot fluid.

In the aforementioned hybrid energy supply system based on a gas turbine and a molten carbonate fuel cell, the products of the air separator are O ₂ and N ₂ products.

In the above-mentioned hybrid energy supply system based on gas turbine and molten carbonate fuel cell, the heating heat source of the fuel preheater is the high-temperature flue gas of the gas turbine.

In the above-mentioned hybrid energy supply system based on gas turbine and molten carbonate fuel cell, the heating heat source of the gas preheater is the high-temperature flue gas of the gas turbine.

In the aforementioned hybrid energy supply system based on a gas turbine and a molten carbonate fuel cell, the products of the reformer are CO and H ₂ .

In the aforementioned hybrid energy supply system based on a gas turbine and a molten carbonate fuel cell, the electrochemical reaction in the solid oxide fuel cell is H ₂ and O ₂ .

The above-mentioned hybrid energy supply system based on gas turbine and molten carbonate fuel cell, wherein, part of the high-temperature flue gas generated by the gas turbine enters the combustion chamber, and the other part first enters the reformer, and then enters the fuel preheater and gas preheater. heater.

In the above-mentioned hybrid energy supply system based on gas turbine and molten carbonate fuel cell, the VM cycle heat pump supplies the domestic hot water load through the hot cavity, supplies the cooling capacity required by users through the cold cavity, and supplies heat through the room temperature cavity.

The above-mentioned hybrid energy supply system based on gas turbine and molten carbonate fuel cell, wherein, the heat exchanger I is connected with the heat chamber of the VM cycle heat pump and operates throughout the year.

In the aforementioned hybrid energy supply system based on gas turbines and molten carbonate fuel cells, the heat exchanger II is connected to the chamber of the VM cycle heat pump at room temperature, and operates in winter and stops in summer.

In the aforementioned hybrid energy supply system based on gas turbines and molten carbonate fuel cells, the heat exchanger III is connected to the cold chamber of the VM cycle heat pump, and operates in summer and stops in winter.

The above technical solution has the following advantages or beneficial effects:

1. The combination of solid oxide fuel cell and oxygen-enriched combustion power generation method can not only ensure the power generation of the system, but also make full use of energy.

2. The exhaust gas from the gas turbine first passes through the reformer to heat the fuel, then drives the VM cycle heat pump, and finally uses the hot water in the hot chamber of the VM cycle heat pump to preheat the fuel and air. , and save energy.

3. This system combines the VM cycle heat pump with the solid oxide fuel cell, and has various energy supply methods, further excavating the energy-saving potential and driving flexibility of the VM cycle heat pump.

Description of drawings

The invention and its characteristics, configurations and advantages will become more apparent by reading the detailed description of non-limiting embodiments made with reference to the following drawings. Like numbers designate like parts throughout the drawings. The drawings are not intended to be drawn to scale, emphasis instead being placed upon illustrating the gist of the invention.

Figure 1. Schematic diagram of the hybrid energy supply system based on gas turbine and solid oxide fuel cell

Figure 2. Working principle diagram of solid oxide fuel cell

The meanings of the symbols in the figure are as follows: 1-compressor; 2-air separator; 3-fuel preheater; 4-gas preheater; 5-reformer; 6-solid oxide fuel cell; 7-combustion chamber ; 8-gas turbine; 9-generator; 10-VM cycle heat pump; 11-heat exchanger I; 12-heat exchanger II; 13-heat exchanger III;

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, but not as a limitation of the present invention.

The working principle of the VM cycle heat pump refers to the Chinese patent CN101865566A.

As shown in Figure 1, the system includes: compressor 1, air separator 2, fuel preheater 3, gas preheater 4, reformer 5, solid oxide fuel cell 6, combustion chamber 7, gas turbine 8, Generator 9, VM cycle heat pump 10, heat exchanger I 11, heat exchanger II 12, heat exchanger III 13. The air is compressed by the compressor 1 and enters the air separator 2 for gas separation to obtain _O2 and _N2 products. Part of the _O2 enters the solid oxide fuel cell 6 after being heated by the gas preheater 4, and the other part of _O2 enters the combustion chamber 7 After the fuel is heated by the fuel preheater 3, a part of the fuel is reformed by the reformer 5 to obtain H ₂ enters the solid oxide fuel cell 6, and O ₂ electrochemically reacts and generates electricity; another part of the fuel, reformed CO, flue gas, O ₂ and the product H ₂ O of the solid oxide fuel cell 6 enter the combustion chamber 7 for oxygen-enriched combustion, and the high-temperature flue gas generated enters the gas turbine 8 to expand and perform work, and makes the generator 9 generate electricity; finally, the gas turbine 8 Part of the 800°C high-temperature flue gas is returned to the combustion chamber 7 to adjust the _O2 content of the oxygen-enriched combustion within a reasonable range, and the other part of the high-temperature flue gas is first heated to the reformer 5 to stabilize the _H2 output required by the solid oxide fuel cell 6 , reheat the fuel preheater 3 and the gas preheater 2, so that the solid oxide fuel cell 6 maintains a reasonable operating temperature range, and finally drives the VM cycle heat pump 10, and absorbs heat from the outside through the heat exchanger II 12 for cooling in summer, Heat is supplied to users through heat exchanger III 13 in winter, and heat exchanger I 11 supplies domestic hot water throughout the year.

The working principle diagram of the solid oxide fuel cell is introduced below in combination with FIG. 2 .

The solid oxide fuel cell 6 in Fig. 2 mainly includes three parts: solid electrolyte E, anode A, and cathode C. When the solid oxide fuel cell 6 is working, electrons flow from the anode to the cathode through an external circuit, and oxygen molecules get electrons and are reduced to oxygen Under the action of the potential difference and the driving force of the oxygen concentration difference, the oxygen ions transition to the anode through the oxygen vacancies in the electrolyte to undergo an oxidation reaction, and the electrons released by the anode reaction flow back to the cathode through an external circuit.

Those skilled in the art should understand that those skilled in the art can implement the variation examples in combination with the prior art and the foregoing embodiments, which will not be repeated here. Such variations do not affect the essence of the present invention, and will not be repeated here.

The preferred embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and the devices and structures that are not described in detail should be understood to be implemented in a common manner in the art; Many possible changes and modifications are made in the technical solution of the invention, or modified into equivalent embodiments with equivalent changes, which do not affect the essence of the present invention. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments according to the technical essence of the present invention, which do not deviate from the technical solution of the present invention, still fall within the protection scope of the technical solution of the present invention.

Claims (3)

1. the mixing energy supplying system based on gas turbine and solid oxide fuel cell, it is characterised in that：It include compressor, Air separator, fuel preheater, gas preheater, reformer, solid oxide fuel cell, combustion chamber, gas turbine, hair Motor, VM circulating heat pumps, heat exchanger I, heat exchanger II, heat exchanger III；The VM circulating heat pumps include hot chamber, room temperature chamber, cold Chamber；

Air obtains O after compressor compresses into air separator₂And N₂Product, a part of O₂By gas preheater plus Enter solid oxide fuel cell, another part O after heat₂Into combustion chamber；With CH₄Based on gaseous fuel through fuel preheating After device heating, a part obtains H by reformer₂Into solid oxide fuel cell, with O₂It is concurrent that electrochemical reaction occurs Electricity；Another part is with CH₄Based on gaseous fuel, product CO, O after fuel reforming₂, flue gas and solid oxide fuel electricity Part H in the product of pond₂O carries out rich support and burns in the combustion chamber, generates high-temperature gas and enters gas turbine expansion work, and makes Electrical power generators；Meanwhile VM circulating heat pumps, summer is driven to absorb heat from the external world by cold chamber and carry out using gas turbine flue gas Refrigeration, winter are heated by room temperature chamber to user, the hot annual domestic hot-water of chamber supply.

2. the mixing energy supplying system based on gas turbine and solid oxide fuel cell as described in claim 1, feature It is, the driving heat source temperature of the VM circulating heat pumps is in the range of 800-900K.

3. the mixing energy supplying system based on gas turbine and solid oxide fuel cell as described in claim 1, feature It is, the flue gas is the high-temperature flue gas after gas turbine acting, and a part of high temperature gases recirculating to combustion chamber adjusts rich The O of oxygen burning₂Content is within the scope of 27-39%, another part high-temperature flue gas elder generation heated reformate device, stabilization of solid oxide fuel H needed for battery₂Yield reheats fuel preheater and gas preheater, and solid oxide fuel cell is made to keep rational Operating temperature range finally drives VM circulating heat pumps.