Combined power generation equipment and power generation method based on solid oxide fuel cell

Abstract

The invention discloses combined power generation equipment based on a solid oxide fuel cell and a power generation method. The combined power generation equipment comprises a solid oxide fuel cell system, a fuel turbine power generation system, an optional coal gasification system and an optional synthesis gas purification system, the solid oxide fuel cell system comprises a columnar cell box, and a cell pack, a feed gas inlet pipeline, an air inlet pipeline, a first shunt, a second shunt, an anode current collector, an anode exhaust pipeline, a cathode current collector and a cathode exhaust pipeline which are accommodated in the columnar cell box, wherein the cell pack is provided with a plurality of solid oxide fuel cell units; the gas turbine power generation system comprises an air inlet, a combustion chamber, a turbine and a generator. Based on the power generation advantage of the solid oxide fuel cell, upstream and downstream systems are linked, multi-stage energy recovery is achieved, the energy utilization rate is increased, meanwhile, the working temperature of the solid oxide fuel cell is reduced, the starting speed is increased, the multi-power selection applicability of combined power generation equipment is expanded, and great application advantages are achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of solid oxide fuel cells, and in particular to a combined power generation device and a power generation method based on solid oxide fuel cells. Background Art

[0002] Solid Oxide Fuel Cell (SOFC) is a fuel cell with solid oxide as electrolyte. Its operating temperature is generally between 600℃ and 1000℃. It directly converts chemical energy into electrical energy through electrochemical reactions in high temperature environment. It has made remarkable development in the past few decades. Compared with traditional internal combustion engines and gas turbines, SOFC has higher energy conversion efficiency (50%-60% primary power generation efficiency) and lower pollutant emissions. It is low in cost and has good long-term stability. In particular, it can directly use a variety of carbon-containing fuels, such as natural gas (CH4) represented by fossil fuels, coal gas (underground gasification gas, coke oven gas, coalbed methane, etc.) and other gas fuels. It can also be further expanded to renewable biomass fuels such as biogas and biomass gas. It has a wide source, is compatible with the existing energy resource supply system and has considerable development prospects.

[0003] Invention CN104025356B discloses a zero-emission power station with carbon dioxide waste gas utilization, which utilizes a clean energy system, a renewable energy system or a zero-emission energy system (ZEES) of CO2 waste gas. The energy system may include a fuel processor, an energy catalytic reactor and a generator. The fuel processor may catalytically convert the CH4 component in natural gas, biogas or synthesis gas into a reforming product containing H2, CO, CO2 and H2O substances. The energy reactor may convert the reforming product in gaseous form into a liquid fuel. The generator may generate electricity using the output of the fuel processor and / or the output of the energy reactor. The invention provides a variety of specific clean energy systems and power generation methods, including a scheme for generating electricity using SOFC and recycling the generated CO2, but the clean energy system proposed in the invention does not clearly disclose the specific system equipment and connection method, and the operating temperature is high, and the utilization of energy such as high-temperature tail gas and combustion waste heat is not sufficient, resulting in a high overall power generation cost.

[0004] Invention CN110257106B discloses an integrated coal gasification fuel cell power generation system and method using water-coal slurry gasification, including a coal preparation unit, a gasifier, a waste heat boiler, a dust removal unit, a first gas-to-gas heater, a desulfurization device, an ejector, a fuel cell, a pure oxygen burner, a gas turbine, a cathode air compressor, a first waste heat recovery heat exchanger, a cathode regenerator, an air turbine, a steam turbine, a waste heat boiler and a cryogenic air separation unit. The invention avoids the energy loss caused by the water-gas conversion process by optimizing the process structure and method, but due to the long startup time of SOFC, the first waste heat recovery heat exchanger and the cathode regenerator and other units need to start working after SOFC is started, which will significantly affect the thermal efficiency of the system.

[0005] Therefore, how to utilize the power generation advantages of solid oxide fuel cells, realize linkage with their upstream and downstream equipment, realize multi-stage energy recovery within the combined power generation equipment, improve energy utilization, and at the same time reduce the operating temperature, speed up the startup speed of solid oxide fuel cells, and expand the applicability of equipment with multiple power options is an urgent problem to be solved by technical personnel in this field. Summary of the invention

[0006] In view of the defects existing in the above-mentioned prior art, the present invention provides a combined power generation equipment and power generation method based on solid oxide fuel cells, which integrates a solid oxide fuel cell system, a fuel turbine power generation system, and an optional coal gasification system and a synthesis gas purification system, realizes multi-stage energy recovery inside the combined power generation equipment, improves energy utilization, and utilizes a high-frequency induction heating coil outside the battery pack to quickly heat the battery pack while preheating the battery pack with high-temperature raw gas, thereby accelerating the startup speed of the solid oxide fuel cell.

[0007] In a first aspect, the present invention provides a combined power generation device based on a solid oxide fuel cell, comprising:

[0008] Solid oxide fuel cell systems and fuel turbine power generation systems;

[0009] The solid oxide fuel cell system comprises a cylindrical battery box, and a battery pack having a plurality of solid oxide fuel cell units, a raw gas intake pipe, an air intake pipe, a first flow divider, a second flow divider, an anode current collector, an anode exhaust pipe, a cathode current collector and a cathode exhaust pipe housed in the cylindrical battery box;

[0010] The raw gas inlet pipeline passes the raw gas into the anode of the battery unit through the first splitter, and the air inlet pipeline passes the air into the cathode of the battery unit through the second splitter;

[0011] The anode exhaust of the battery unit is passed into the anode exhaust pipe through the anode current collector, and the cathode exhaust is passed into the cathode exhaust pipe through the cathode current collector. The anode exhaust pipe is connected to the raw gas intake pipe for heat exchange, and the cathode exhaust pipe is connected to the air intake pipe for heat exchange;

[0012] The gas turbine power generation system includes an air inlet, a combustion chamber, a steam turbine and a generator;

[0013] The combustion chamber includes a first air inlet, a second air inlet, a third air inlet and a steam outlet. The first air inlet is connected to the air intake, the second air inlet is connected to the anode exhaust pipe of the solid oxide fuel cell system, the third air inlet is connected to the cathode exhaust pipe, and the steam outlet is connected to the steam turbine. The steam turbine and the generator are connected by a transmission shaft.

[0014] During the operation of SOFC, high-temperature anode exhaust gas and cathode exhaust gas are generated. In the combined power generation equipment of the present invention, the high-temperature exhaust gas of SOFC is first used for heat exchange and temperature increase of the raw gas and air entering the SOFC, thereby improving the power generation efficiency of SOFC. The exhaust gas cooled by heat exchange is further introduced into the combustion chamber of the fuel turbine gas turbine, and the unreacted raw gas and the air introduced through the air inlet are burned in the combustion chamber to obtain high-temperature steam. The high-temperature steam enters the steam turbine from the steam outlet, drives the steam turbine to rotate, and drives the generator to output alternating current through the transmission shaft, thereby fully utilizing the high-temperature exhaust gas.

[0015] Preferably, the gas turbine power generation system also includes an air splitter, which splits the air entering the air inlet into a first air flow and a second air flow, the first air flow enters the combustion chamber from the first air inlet, and the second air flow is connected to the air inlet duct of the solid oxide fuel cell system after heat exchange with the outlet pipe of the steam turbine. The temperature of the high-temperature exhaust gas discharged from the outlet pipe of the steam turbine is usually between 450℃ and 550℃. The second air flow split by the air splitter is heat exchanged with the above-mentioned high-temperature exhaust gas to increase the temperature, and the exhaust gas is cooled for subsequent collection or treatment, so as to realize the utilization of heat energy in the gas turbine power generation system; on the other hand, the preliminarily preheated second air flow will not affect the operation of the battery stack due to excessive temperature difference after entering the cylindrical battery box, and it is also conducive to further heat exchange and temperature increase with the high-temperature cathode exhaust.

[0016] Preferably, the raw gas inlet pipeline extends along the central axis of the battery box, the inlet end of the raw gas inlet pipeline passes through the top of the battery box upward, and the outlet end is connected to the first diverter at the bottom of the battery box;

[0017] The anode exhaust pipe is stacked on the outer periphery of the raw gas intake pipe, the intake end of the raw gas intake pipe is connected to the anode current collector at the bottom of the battery box, and the outlet end passes through the battery box through the exhaust port on the battery box wall;

[0018] The cathode exhaust duct and the air intake duct are stacked and arranged on the inner wall surface of the battery box, and the cathode exhaust duct passes through the battery box through the exhaust port.

[0019] A cylindrical battery box is used, and the raw gas intake pipe and the anode exhaust pipe are extended along the central axis to form a uniform gas supply and gas collection structure in the circumferential direction. The cathode exhaust pipe and the air intake pipe are stacked on the inner wall of the battery box, so that a space for accommodating the battery pack is formed between the central axis formed by the raw gas intake pipe and the anode exhaust pipe and the wall surface where the cathode exhaust pipe and the air intake pipe are stacked, which can form a compact arrangement of the solid oxide fuel cell system and reduce the system footprint. Among them, on the inner wall of the battery box, it is preferred to arrange the relatively low-temperature air intake pipe on the outside, and the high-temperature cathode exhaust pipe on the inside of the air intake pipe, so that the system has a lower impact on external heat radiation.

[0020] More preferably, the stacking surface of the anode exhaust pipe and the raw gas intake pipe, and the stacking surface of the cathode exhaust pipe and the air intake pipe are all corrugated heat exchange structures, and the corrugated heat exchange structure includes a metal corrugated plate, and the thickness of the metal corrugated plate is 50-500μm, preferably 100-200μm, which enhances the heat transfer efficiency while ensuring the basic mechanical strength. Compared with the planar heat exchange structure, the corrugated heat exchange structure is more conducive to increasing the heat exchange area and improving the heat exchange efficiency. At the same time, the corrugated heat exchange structure also helps to reduce the flow resistance inside the pipeline and reduce unnecessary energy loss. In addition, the structure also has excellent mechanical support performance, ensuring the stable operation and long service life of the pipeline.

[0021] Preferably, a plurality of the battery packs are arranged in the space around the raw gas inlet pipe, and each battery pack is formed into a columnar structure by stacking a plurality of battery units;

[0022] The battery cell includes a stacked anode-side connecting plate, an anode functional layer, an electrolyte layer, a cathode functional layer, and a cathode-side connecting plate;

[0023] Induction heating coils are arranged around the columnar structures of each battery pack, and the induction heating coils are connected to the generator of the gas turbine power generation system.

[0024] For plate-type battery cells, usually one battery cell can generate a voltage of 0.5-1V. In order to generate a sufficiently high voltage, several battery cells need to be stacked to form a series structure, i.e., a battery pack or a battery stack. And the power of the battery pack or battery stack must be as high as possible to realize a large-scale, high-power power generation system. At present, the power of a single battery pack or battery stack is relatively small, about 1-10kW. It is reported that Mitsubishi Heavy Industries has provided a 15kW battery pack in the experimental stage. In order to realize a higher power generation system, such as building a power generation system of tens of kilowatts, hundreds of kilowatts or more, combining multiple battery packs to work is currently the main means. The present invention combines multiple battery packs to form a compact solid oxide fuel cell system with a ring distribution, and cooperates with a fuel turbine power generation system, etc., to provide a combined power generation system from tens of kilowatts to hundreds of kilowatts, which has great application advantages in high-power power generation systems based on SOFC.

[0025] Preferably, the induction heating coil is a hollow tube made of a heat-resistant metal material, and the outer surface of the hollow tube is coated with a metal oxide barrier layer. The induction heating coil uses the principle of electromagnetic induction heating, and utilizes the hysteresis loss to heat the component through the generated eddy current and hysteresis loss. When current is applied to the induction heating coil, induced eddy currents are generated due to the setting of the conductive material. These eddy currents cause hysteresis losses, which will be reflected in the conductive material part in the form of heat, and the battery pack can be heated to the operating temperature in a short time, ensuring that the SOFC starts quickly and enters a normal working state, for example, within 10 minutes, preferably within 8 minutes, that is, the battery pack is heated to 600°C to 750°C. The induction heating coil greatly shortens the startup time of the SOFC, thereby improving the response speed and practicality of the system. At the same time, precise temperature control can be achieved through induction heating, which improves the reliability of the system.

[0026] The induction heating coil is a good conductor and can show good conductivity even in a high temperature and oxidizing atmosphere. Heat-resistant steel, heat-resistant copper or heat-resistant copper alloy is preferred. The induction heating coil is arranged around the cylindrical battery box. Although its rapid heating effect is mainly used for the rapid start-up of the battery, it is exposed to the same high temperature and oxidizing atmosphere operating environment as the battery pack. In order to inhibit oxidation and increase the life of the coil, a metal oxide barrier layer is coated to avoid direct contact with the atmosphere or exhaust gas. The metal oxide barrier layer preferably has the characteristics of low magnetic permeability and low thickness, such as aluminum oxide, chromium oxide and titanium dioxide. Secondly, the induction heating coil is set as a hollow tube. When the induction heating coil is not used during normal operation, a cooling fluid (such as cooling water) is used to flow through the hollow tube to cool the coil. This design is not only conducive to controlling the coil heating process, but also conducive to forming an anti-overheating protection for the induction heating coil, extending the service life of the coil, and reducing maintenance and replacement costs.

[0027] Preferably, the battery unit further includes at least one of the following:

[0028] (1) The anode-side connecting plate has a first convex rib and a first fluid groove at least on the side facing the anode, and a Cr volatilization-proof coating is provided on at least the surface of the first convex rib;

[0029] (2) The cathode-side connecting plate has a second convex rib and a second fluid groove at least on the side facing the cathode, and a Cr volatilization-proof coating is provided on at least the surface of the second convex rib;

[0030] (3) The electrolyte layer includes a three-layer structure of BCSCuO / SDC / PSDC, where BCSCuO is connected to the anode functional layer and PSDC is connected to the cathode functional layer;

[0031] (4) The anode functional layer comprises NiO-BCSCuO;

[0032] (5) The cathode functional layer comprises LSM-SDC or LSCF-SDC.

[0033] When arranged between two battery cells, the anode side connecting plate and the cathode side connecting plate may actually be a connecting plate assembly, with convex ribs and fluid grooves respectively arranged on both sides of the connecting plate assembly. At this time, the two sides of the connecting plate assembly are divided into the anode side and the cathode side.

[0034] The anode side connecting plate, cathode side connecting plate and the aforementioned connecting plate assembly can be made of ferritic stainless steel (FSS) or Fe-Cr alloy (such as Crofer-22 APU or Crofer-22HCr). The material of the anti-Cr volatilization coating can be selected from rare earth metal (Y, La, Ce, Hf, etc.) oxide materials, perovskite oxide materials (LaCoO3, LaCaCoO3, La 1-x Sr x CoO3、La 1- x Sr xMnO3, etc.), spinel oxides ((MnCo)3O4, (MnNi)3O4, MnCr2O4, NiFe2O4, etc.) to improve its antioxidant capacity. Among them, it is more preferred to use SUS430 ferritic stainless steel to manufacture the aforementioned connecting plate, and use magnetron sputtering to deposit a NiFe2 coating on its surface for 1-3h to obtain a thickness of about 0.5-4mm. The coating is sintered in an oxidizing environment of 800±20℃ to form a three-layer structure, from top to bottom Fe2O3-NiFe2O4-NiO, and the coating is a dense coating with closed pores. More preferably, in order to prevent the diffusion of elements between the aforementioned coating and the connecting plate substrate, it is more preferred to prepare a CrN diffusion prevention layer on the SUS430 ferritic stainless steel in advance, and then deposit NiFe2, and obtain Fe2O3-NiFe2O4-NiO-CrN through oxidation sintering at 800±20℃. The coating exhibits better antioxidant and Cr resistance effects, and is also beneficial to reducing the surface specific resistance ASR.

[0035] Regarding the material and structure of the electrolyte layer. First, in a medium-temperature solid oxide fuel cell with an operating temperature range of 600-750°C, SDC is used as the solid electrolyte layer, and its oxygen ion conductivity is improved by about one order of magnitude relative to the existing common YSZ. In addition, in order to prevent or reduce the electron conduction of the SDC solid electrolyte layer under reducing conditions, resulting in the occurrence of electron leakage current, and thus causing a decrease in the fuel efficiency and energy efficiency of the entire device, the present invention forms a BCSCuO anode barrier layer on the anode side to block the electron current in the electrolyte. Compared with forming a YSZ barrier layer on the SDC layer, the BCSCuO / SDC combination has a denser structure and a more compatible thermal expansion coefficient.

[0036] The specific production process includes: Based on Ce 0.8 Sm 0.2 O 1.9 The supporting electrolyte layer of cerium dioxide (SDC) is formed on one side of the anode barrier layer, and on the other side of the cathode modification layer. The anode barrier layer is made of a material based on barium cerate, and BaCe doped with samarium and copper 0.8 Sm 0.19 Cu 0.1 O3 (BCSCuO), applied to the SDC electrolyte layer by electrophoretic deposition and sintered at 1500-1550°C for 4-6 hours. The cathode modification layer is made of a cerium dioxide material based on doped samarium and praseodymium, with a composition of Ce 0.8 (Sm 0.5 Pr 0.5 ) 0.2 O 1.9 (PSDC) was deposited onto the SDC electrolyte layer by electrophoresis and sintered at 1400-1550°C for 4-6 hours.

[0037] Based on the design of the electrolyte layer, the present invention provides a corresponding anode functional layer and cathode functional layer. Preferably, the anode functional layer comprises NiO-BaCe with a thickness of 10-30 μm. 0.8 Sm 0.19 Cu 0.1 O3, NiO and BaCe 0.8 Sm 0.19 Cu 0.1 The mass ratio of O3 is (50-55): (45-50). Preferably, the cathode functional layer comprises (La 0.8 Sr 0.2 ) 0.98 MnO3(LSM)-SDC or La 0.6 Sr 0.4 Fe 0.8 Co 0.2 O3(LSCF)-SDC, wherein the mass ratio of LSM or LSCF to SDC is (55-65):(35-45).

[0038] Preferably, the combined power generation equipment further comprises a coal gasification system and a synthesis gas purification system;

[0039] The coal gasification system includes a water-coal slurry preparation unit and a gasifier to produce synthesis gas;

[0040] The synthesis gas purification system includes a dust removal unit and a desulfurization unit, which purify the synthesis gas into raw gas. The raw gas enters the raw gas inlet pipeline after heat exchange with the synthesis gas and temperature rises.

[0041] The combined power generation equipment also includes an air separation device. The oxygen obtained after the air passes through the air separation device is respectively introduced into the gasifier of the coal gasification system and the air intake pipe of the solid oxide fuel cell system, as well as the air intake of the optional gas turbine power generation system. The amount of oxygen introduced into the gasifier by the air separation device is 300-1000Nm per ton of dry coal. 3 Oxygen, the ratio of oxygen entering the gasifier to oxygen entering the combustion chamber for heat exchange is 1:(10-30), and the volume ratio of raw gas entering the anode to oxygen entering the cathode is 1:(5-15).

[0042] Preferably, the combined power generation equipment also includes a control system, which detects the temperature of at least one battery stack and the temperature of the induction heating coil through a temperature sensor, and controls the operation of the solid oxide fuel cell system, the fuel turbine power generation system, the coal gasification system and the synthesis gas purification system.

[0043] In a second aspect, the invention further provides a combined power generation method using the combined power generation device, comprising the following steps:

[0044] S1, the raw gas is introduced into the anode of the solid oxide fuel cell unit through the raw gas inlet pipeline and the first splitter, and the air is introduced into the cathode of the solid oxide fuel cell unit through the air inlet pipeline and the second splitter, and the raw gas and air react chemically in the solid oxide fuel cell unit to output electrical energy;

[0045] S2, the high-temperature anode exhaust gas is passed into the anode exhaust pipe through the anode current collector and heat-exchanged with the raw gas inlet pipe; the high-temperature cathode exhaust gas is passed into the cathode exhaust pipe through the cathode current collector and heat-exchanged with the air inlet pipe;

[0046] S3. The anode exhaust and cathode exhaust after heat exchange enter the combustion chamber of the gas turbine power generation system, and burn with the air introduced from the air inlet in the combustion chamber to obtain high-temperature steam. The high-temperature steam enters the steam turbine from the steam outlet, drives the steam turbine to rotate, and drives the generator to output AC power through the transmission shaft.

[0047] Preferably, the raw gas is prepared by the following steps:

[0048] The raw gas is prepared by the following steps:

[0049] (1) Coal gasification process: Raw coal and water are ground and slurried in the water-coal slurry preparation unit before entering the gasifier, where the gasification reaction produces high-temperature syngas;

[0050] (2) Synthesis gas purification process: Synthesis gas is dedusted to remove particulate matter, and the sulfur concentration is reduced in the desulfurization unit to obtain raw gas;

[0051] (3) Heat exchange and temperature raising process: The raw gas is heated by heat exchange with the high-temperature synthesis gas obtained in step (1) and then enters the raw gas inlet pipeline. The synthesis gas after heat exchange enters the synthesis gas purification process in step (2).

[0052] Preferably, the induction heating coils arranged around each battery pack are used to quickly heat up the battery pack and start the battery pack, comprising the following steps:

[0053] Step 1: The high-temperature raw gas preheats the battery pack through the raw gas intake pipe, and then enters the combustion chamber of the gas turbine power generation system through the anode exhaust pipe, and burns with the air introduced into the air inlet in the combustion chamber to obtain high-temperature steam. The high-temperature steam enters the steam turbine from the steam outlet, drives the steam turbine to rotate, and drives the generator to output AC power through the transmission shaft;

[0054] Step 2, the generator supplies power to the induction heating coil connected thereto, performs induction heating on the battery pack, and raises the temperature of the battery pack to 600° C. to 750° C. within 10 minutes;

[0055] Step 3: supply air to the cathode of the solid oxide fuel cell unit through the air intake pipe, and proceed to the above-mentioned step S1.

[0056] At the initial start-up of the combined power generation equipment, the raw gas that has been heated by heat exchange with the high-temperature synthesis gas is first preheated to preheat the battery pack, and the unreacted raw gas is then directly burned in the gas turbine power generation system to generate alternating current to quickly start the induction heating coil, induction heat the conductive material in the battery pack, and quickly heat the battery pack to the basic working temperature. In order to start faster, the induction heating coil can also be started by other external alternating current supply equipment or power grid, but it is more preferably supplied by the generator of the gas turbine power generation system of the combined power generation equipment. In step three, when the temperature of the battery pack reaches the normal operating temperature, the generator stops outputting alternating current to the induction heating coil. The alternating current generated by the generator can be switched to other power-consuming components of the combined power generation equipment, and can also be transmitted to the outside. Cooling water is passed into the hollow tube of the induction heating coil to cool down and prevent damage to the induction heating coil. The heat exchanged water can be output or circulated in the system.

[0057] The present invention has at least the following beneficial effects:

[0058] (1) The combined power generation equipment of the solid oxide fuel cell system and the fuel turbine power generation system of the present invention integrates the core advantages of the two power generation technologies, realizes the efficient use of energy, and significantly improves the energy utilization efficiency of the system. The system not only utilizes the efficient and clean power generation characteristics of the solid oxide fuel cell, but also provides thermal energy for the gas turbine by recycling the heat generated by it, further improving the overall energy utilization efficiency. At the same time, the system also optimizes thermal management technology to ensure that heat can be reasonably and efficiently utilized under various working conditions to maximize energy utilization. In addition, the compact structural design of the columnar battery box is conducive to reducing the floor space and facilitating the maintenance and replacement of the battery pack. The independence of the gas turbine system also enables it to flexibly adapt to different heat sources.

[0059] (2) The present invention specifically utilizes the generator of the fuel turbine power generation system to provide alternating current to the induction heating coil, thereby quickly raising the temperature of the battery pack to the operating temperature while preheating the high-temperature raw gas, thereby overcoming the problems of slow start-up and high energy consumption of the solid oxide fuel cell.

[0060] (3) The present invention adopts an efficient heat exchange system design method, especially setting the air intake duct and the exhaust duct of the solid oxide fuel cell as a corrugated interlocking structure, which effectively increases the heat exchange area, improves the heat exchange efficiency between the high-temperature exhaust gas and the intake air, and is beneficial to improving the overall mechanical properties of the cylindrical battery box and extending the service life of the combined power generation equipment.

[0061] (4) Modular design and integrated joint operation of equipment. The solid oxide fuel cell system, fuel turbine power generation system, coal gasification system and synthesis gas purification system together constitute the integrated coal gasification fuel cell power generation system (IGFC). The system can be adjusted and expanded according to different application requirements and obtain a higher net electrical efficiency than traditional technologies. The net electrical efficiency is greater than 70%, preferably greater than 75%, which greatly improves the efficiency of coal-fired power generation and makes it easy to achieve near-zero emissions of pollutants and carbon dioxide. It is an important development direction for the application of clean coal power generation technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Figure 1 A schematic diagram of the structure of a combined power generation device including a solid oxide fuel cell system and a fuel turbine power generation system;

[0063] Figure 2 It is a schematic diagram of the structure of the battery pack and the induction heating coil of the present invention;

[0064] Figure 3 for Figure 2 An enlarged schematic diagram of the battery pack A area;

[0065] Figure 4 A connection diagram of the combined power generation equipment of the present invention;

[0066] Figure 5a It is a schematic diagram of the corrugated heat exchange structure of the raw gas inlet pipe and the anode exhaust pipe;

[0067] Figure 5b Schematic diagram of the corrugated heat exchange structure of the cathode exhaust duct and the air intake duct.

[0068] Figure markings: 1-solid oxide fuel cell system, 11-battery pack, 111-anode functional layer, 112-cathode functional layer, 1131-anode barrier layer, 1132-core layer, 1133-cathode modification layer, 1141-first convex rib, 1142-second convex rib, 115-anode side connecting plate, 116-cathode side connecting plate, 12-raw gas inlet pipe, 13-air inlet pipe, 14-anode exhaust pipe, 15-cathode exhaust pipe, 16-induction coil, 2-fuel turbine power generation system, 21-air inlet, 22-combustion chamber, 221-first air inlet, 222-second air inlet, 223-third air inlet, 224-steam outlet, 23-steam turbine, 31-water-coal slurry preparation unit, 32-gasifier, 33-heat exchanger, 34-dust removal unit, 35-desulfurization unit, 36-air separation unit. DETAILED DESCRIPTION

[0069] In order to better understand the above technical solution, the above technical solution will be described in detail below in combination with the specification and specific implementation methods. 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 making creative work are within the scope of protection of the present invention.

[0070] The terms used in the embodiments of the present invention are only for the purpose of describing specific embodiments, and are not intended to limit the present invention. The singular forms "a", "said" and "the" used in the embodiments of the present invention and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings, and "multiple" generally includes at least two.

[0071] It should also be noted that the term "includes", "comprising" or any other variation thereof is intended to cover non-exclusive inclusion, so that a commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprising a ..." do not exclude the existence of other identical elements in the commodity or device including the elements.

[0072] See attached Figure 1-4 , a combined power generation device based on a solid oxide fuel cell, comprising:

[0073] 1. A solid oxide fuel cell system 1, comprising:

[0074] (1.1) Columnar battery box;

[0075] (1.2) A plurality of battery packs 11 are accommodated in the columnar battery box, preferably including 3-20 battery packs 11, each battery pack 11 is formed by stacking a plurality of solid oxide fuel cell units into a columnar structure, and each battery pack 11 preferably includes 5-60 battery units; when there are a large number of battery packs 11, they can be arranged in multiple layers of loops from the axis outward along the radial direction of the columnar battery box to achieve a compact layout; currently, the electric power of a single battery pack 11 is about 1-10kW. If a SOFC power generation system with a power of tens of kilowatts, hundreds of kilowatts or more is to be constructed, multiple battery packs 11 can be combined to work, which has great application advantages in high-power SOFC power generation systems;

[0076] The battery cell includes a stacked anode side connecting plate 115, an anode functional layer 111, an electrolyte layer, a cathode functional layer 112 and a cathode side connecting plate 114. Figure 3 The specific battery cell further includes at least one of the following, preferably at least three of the following:

[0077] (1) The anode side connecting plate 115 has a first convex rib 1141 and a first fluid groove at least on the side facing the anode, and a Cr volatilization prevention coating is provided on at least the surface of the first convex rib 1141; the thickness of the anode side connecting plate 115 is 0.5-3 mm, preferably 1-2 mm, wherein the thickness of the first convex rib 1141 is 0.2-2.5 mm, preferably 0.5-1 mm, and the thickness of the Cr volatilization prevention coating is about 0.5-4 mm, preferably 1-3 mm;

[0078] (2) The cathode side connecting plate 114 has a second convex rib 1142 and a second fluid groove at least on the side facing the cathode, and a Cr volatilization prevention coating is provided on at least the surface of the second convex rib 1142; the cathode side connecting plate 114 has a thickness of 0.5-3 mm, preferably 1-2 mm, wherein the second convex rib 1142 has a thickness of 0.2-2.5 mm, preferably 0.5-1 mm, and the Cr volatilization prevention coating has a thickness of about 0.5-4 mm, preferably 1-3 mm;

[0079] (3) The electrolyte layer includes a three-layer structure of BCSCuO (anode barrier layer 1131) / SDC (core layer 1132) / PSDC (cathode modification layer 1133), wherein the BCSCuO anode barrier layer 1131 is connected to the anode functional layer 111, and the PSDC cathode modification layer 1133 is connected to the cathode functional layer 112; the thickness of the electrolyte layer is 50-300 μm, wherein the thickness ratio of the BCSCuO anode barrier layer 1131, the SDC core layer 1132, and the PSDC cathode modification layer 1133 is (3-20): (50-200): (2-20);

[0080] (4) The anode functional layer 111 comprises NiO-BCSCuO with a thickness of 10-30 μm. NiO and BaCe 0.8 Sm 0.19 Cu 0.1 The mass ratio of O3(BCSCuO) is (50-55):(45-50);

[0081] (5) The cathode functional layer 112 includes LSM (La 0.8 Sr 0.2 ) 0.98 MnO3)-SDC or LSCF(La 0.6 Sr 0.4 Fe 0.8 Co 0.2 O3)-SDC, thickness 10-30μm, the mass ratio of LSM or LSCF to SDC is (55-65):(35-45).

[0082] (1.3) Gas pipeline: raw gas inlet pipeline 12, first flow divider, anode current collector, anode exhaust pipeline 14, the raw gas inlet pipeline 12 passes the raw gas into the anode of the solid oxide fuel cell unit through the first flow divider, specifically, the raw gas enters the anode functional layer 111 through the first fluid groove of the anode side connecting plate 115;

[0083] The raw gas inlet pipe 12 extends along the central axis of the battery box, one end of which passes through the top of the battery box upwards, and the other end is connected to the first diverter at the bottom of the battery box. The anode exhaust pipe 14 is stacked on the outer periphery of the raw gas inlet pipe 12, one end of which is connected to the anode current collector at the bottom of the battery box, and the other end passes through the battery box from the exhaust port on the battery box wall. The anode exhaust passes into the anode exhaust pipe 14 through the anode current collector, exchanges heat with the raw gas in the raw gas inlet pipe 12, and is then discharged from the exhaust port; a plurality of the battery packs 11 are arranged in the space around the raw gas inlet pipe 12; the stacking surface of the anode exhaust pipe 14 and the raw gas inlet pipe 12 is a corrugated heat exchange structure, which is beneficial to increase the heat exchange area, improve the heat exchange efficiency, and improve the mechanical strength of the heat exchange area, see the attached Figure 5a .

[0084] (1.4) Gas pipeline 2: air intake pipeline 13, second flow divider, cathode current collector, cathode exhaust pipeline 15, the air intake pipeline 13 passes air into the cathode of the solid oxide fuel cell unit through the second flow divider, specifically, the air enters the cathode functional layer 112 through the second fluid groove of the cathode side connecting plate 114; the first fluid groove and the second fluid groove are arranged so that the inflow direction of the raw gas and the air can be the same flow, cross flow or counter flow;

[0085] The cathode exhaust duct 15 and the air intake duct 13 are stacked and arranged on the inner wall of the battery box, and the cathode exhaust duct 15 passes through the battery box from the exhaust port; the cathode exhaust passes into the cathode exhaust duct 15 through the cathode current collector, exchanges heat with the air in the air intake duct 13, and is discharged from the exhaust port; the stacked surface of the cathode exhaust duct 15 and the air intake duct 13 is a corrugated heat exchange structure, which is beneficial to increase the heat exchange area, improve the heat exchange efficiency, and improve the mechanical strength of the heat exchange area, see the attached Figure 5b .

[0086] (1.5) Induction heating coils are arranged around the columnar structures of each battery pack 11, see the attached Figure 2 , the induction heating coil is connected to the generator of the gas turbine power generation system or to an external power source;

[0087] (1.6) An optional cooling unit, including at least one of a blower, a fan, an air pump or an air compressor, is used to provide air to the battery pack 11 during shutdown operation, and cool the battery stack to below 600°C at a rate of about 1.0°C / min to about 3.0°C / min, preferably about 1.5°C / min to about 2.5°C / min, to reduce or substantially avoid anode oxidation in a high-temperature oxidizing environment. If the cooling rate is too high, excessive thermal stress may occur in the battery stack and / or other system components, resulting in system failure. If the cooling rate is too low, high-temperature oxidation of the anode after the valve of the raw gas inlet pipe 12 is closed may not be avoided. After reaching the above-mentioned safe temperature, the cooling can be stopped, or it can be reduced to a lower temperature as needed.

[0088] 2. Gas turbine power generation system, including:

[0089] (2.1) an air inlet 21, supplying air to at least a combustion chamber 22 of a gas turbine power generation system, an optional air splitter, splitting the air entering the air inlet 21 into a first air flow and a second air flow, the first air flow entering the combustion chamber 22 from a first air inlet 221, and the second air flow exchanging heat with an air outlet pipe of a steam turbine 23 and then connected to an air inlet duct 13 of the solid oxide fuel cell system 1;

[0090] (2.2) a combustion chamber 22, comprising a first air inlet 221, a second air inlet 222, a third air inlet 223 and a steam outlet 224, wherein the first air inlet 221 is connected to the air inlet 21, the second air inlet 222 is connected to the anode exhaust pipe 14 of the solid oxide fuel cell system 1, the third air inlet 223 is connected to the cathode exhaust pipe 15, and the steam outlet 224 is connected to the steam turbine 23;

[0091] (2.3) a steam turbine 23, which is connected to the steam outlet 224 of the combustion chamber 22, and the transmission shaft is connected to the generator, and the outlet pipe (between 470°C and 550°C) can exchange heat with the second air flow branched from the air inlet 21;

[0092] 3. Coal gasification system, including at least:

[0093] (3.1) Coal-water slurry preparation unit 31, the feed port is connected to the water inlet and the raw coal inlet, and the discharge port is connected to the gasifier. The raw coal and water are ground and slurried in this unit to obtain coal-water slurry, which is then sent to the gasifier through the discharge port;

[0094] (3.2) Gasifier 32, where the water-coal slurry reacts with air (preferably pure oxygen obtained from the air separation unit 36) to produce 800-900°C crude high-temperature synthesis gas, the main components of which include H2, CO, CO2, CH4, H2S and water vapor, etc. Preferably, the crude high-temperature synthesis gas is cooled to below 100°C by heat exchange with the downstream purified raw gas before entering the synthesis gas purification system, eliminating the need for an external cooling system;

[0095] 4. Synthesis gas purification system, including at least:

[0096] (4.1) Dust removal unit 34, which can be a bag filter or an electrostatic precipitator, cools and removes dust from the crude high-temperature synthesis gas, reducing the particle content in the crude high-temperature synthesis gas to 100 mg / Nm 3 Below, preferably 80mg / Nm 3 the following;

[0097] Optionally, the dedusted synthesis gas enters a water scrubber for treatment;

[0098] (4.2) Desulfurization unit 35, which can adopt the commonly used low-temperature methanol method or NHD method;

[0099] Optionally, the synthesis gas passing through the desulfurization unit 35 is further passed through the fine desulfurization unit, and the desulfurization unit 35 and the fine desulfurization unit are connected to the sulfur recovery unit; after passing through the fine desulfurization unit 35, the total sulfur content is less than 0.5 ppm, preferably less than 0.3 ppm;

[0100] Optionally, the desulfurized syngas can be further desulfurized with activated carbon to remove heavy metals such as mercury from the syngas to obtain high-quality raw gas with a mercury content of less than 0.02 mg / Nm 3 , preferably less than 0.01 mg / Nm 3 ;

[0101] The temperature of the purified raw gas is relatively low, and it is preferably heated to about 400-550°C after heat exchange with the 800-900°C high-temperature crude synthesis gas, and then fed into the raw gas inlet pipeline 12 of the solid oxide fuel cell system 1;

[0102] 5. Air separation device 36. The oxygen obtained after the air passes through the air separation device 36 can be respectively introduced into the gasifier 32 of the coal gasification system and the air intake pipe 13 of the solid oxide fuel cell system 1, and the air intake 21 of the optional gas turbine power generation system;

[0103] 6. Control system, including: temperature sensors and a number of switches, valve control units, etc., to monitor the various component systems of the combined power generation equipment, including but not limited to detecting the temperature of the battery stack and the temperature of the induction heating coil through temperature sensors, and controlling the operation of the solid oxide fuel cell system 1, the fuel turbine power generation system 2, the coal gasification system and the synthesis gas purification system.

[0104] The present invention also provides a corresponding combined power generation method, comprising the following steps:

[0105] A. Raw gas preparation process:

[0106] (1) Coal gasification process: Raw coal and water are ground and slurried in the water-coal slurry preparation unit 31 and then enter the gasifier 32 for gasification reaction to obtain crude high-temperature synthesis gas;

[0107] (2) Synthesis gas purification process: the synthesis gas is subjected to the dust removal unit 34 to remove particulate matter, the sulfur concentration is reduced in the desulfurization unit 35 and the optional fine desulfurization unit, and activated carbon is optionally used to remove heavy metals such as mercury to obtain raw gas;

[0108] (3) Heat exchange and temperature raising process: After the raw gas and the high-temperature synthesis gas (about 800-900° C.) obtained in step (1) are heat exchanged and heated, the high-temperature raw gas (about 400-550° C.) enters the raw gas inlet pipeline 12, and the synthesis gas (about 100° C. or less) after heat exchange enters the synthesis gas purification process in step (2);

[0109] B. In the startup phase, preferably, the battery packs 11 are quickly heated and started by using induction heating coils arranged around the battery packs 11, including:

[0110] Step 1: The high-temperature raw gas preheats the battery pack 11 through the raw gas inlet pipe 12, and then enters the combustion chamber 22 of the gas turbine power generation system through the anode exhaust pipe 14, and burns with the first air flow introduced into the air inlet 21 in the combustion chamber 22 to obtain high-temperature steam. The high-temperature steam enters the steam turbine 23 from the steam outlet 224, drives the steam turbine 23 to rotate, and drives the generator to output AC power through the transmission shaft; optionally, the second air flow exchanges heat with the outlet pipe of the steam turbine 23 (temperature is about 400-450°C) and is connected to the air inlet pipe 13 of the solid oxide fuel cell system 1 to preheat the battery pack 11, and then the cathode exhaust pipe 15 returns to the combustion chamber 22 of the gas turbine power generation system;

[0111] Step 2: The generator supplies alternating current to the induction heating coil to induction heat the conductive material in the battery pack 11, and the battery pack 11 is heated to 600° C. to 750° C. within 10 minutes, preferably within 8 minutes;

[0112] Step three, supply air to the cathode of the solid oxide fuel cell unit through the air intake duct 13, and enter the normal operation stage; the air introduced here can continue to be provided by the second air flow in step one, and can also be provided by the second air flow after the temperature of the battery pack 11 reaches the operating temperature; wherein, after the combined power generation equipment operates normally, for example, after the temperature of the battery pack 11 reaches the normal operating temperature at 600-750°C, the generator stops outputting AC power to the induction heating coil, and the AC power generated by the generator can be switched to other power-consuming components of the combined power generation equipment, and can also be transmitted to the outside; cooling water is introduced into the hollow tube of the induction heating coil to cool it down and prevent damage to the induction heating coil, and the heat exchange water can be circulated in the system and can also be transmitted to the outside to provide hot water supply.

[0113] C. Stabilizing the combined power generation process:

[0114] S1, the high-temperature raw gas (about 400-550°C) is heat-exchanged with the high-temperature anode exhaust gas again (about 600-700°C) and then respectively introduced into the anode of the solid oxide fuel cell unit through the raw gas inlet pipe 12 and the first splitter, and the preheated second air flow (about 400-450°C) is heat-exchanged with the high-temperature cathode exhaust gas (about 600-700°C) and then respectively introduced into the cathode of the solid oxide fuel cell unit through the air inlet pipe 13 and the second splitter, and the raw gas and air react chemically in the solid oxide fuel cell unit to output electrical energy;

[0115] S2, the high-temperature anode exhaust gas passes through the anode current collector into the anode exhaust pipe 14, and exchanges heat with the raw gas intake pipe 12 through the heat exchanger 33; the high-temperature cathode exhaust gas passes through the cathode current collector into the cathode exhaust pipe 15, and exchanges heat with the air intake pipe 13;

[0116] S3. The anode exhaust and cathode exhaust after heat exchange enter the combustion chamber 22 of the gas turbine power generation system, and burn with the air introduced from the air inlet 21 in the combustion chamber 22 to obtain high-temperature steam. The high-temperature steam enters the steam turbine 23 from the steam outlet 224, drives the steam turbine 23 to rotate, and drives the generator to output AC power through the transmission shaft.

[0117] Example 1

[0118] The combined power generation device based on solid oxide fuel cells of this embodiment includes:

[0119] 1. Solid oxide fuel cell system, comprising:

[0120] (1.1) Columnar battery box;

[0121] (1.2) A plurality of battery packs, housed in the columnar battery box, including 4 battery packs, symmetrically distributed around the raw gas inlet pipe in the columnar battery box, each battery pack is formed by stacking 30 solid oxide fuel cell units to form a columnar structure; each battery unit includes a stacked anode side connection plate, an anode functional layer, an electrolyte layer, a cathode functional layer and a cathode side connection plate, specifically including:

[0122] (1.2.1) The anode side connecting plate has a first convex rib and a first fluid groove on the side facing the anode, and a Cr volatilization prevention coating is provided at least on the surface of the first convex rib; the thickness of the anode side connecting plate is 2 mm, the thickness of the first convex rib is 1 mm, and the thickness of the Cr volatilization prevention coating on the surface of the first convex rib is about 2.5 mm;

[0123] (1.2.2) The cathode side connecting plate has a second convex rib and a second fluid groove on the side facing the cathode, and a Cr volatilization prevention coating is provided at least on the surface of the second convex rib; the cathode side connecting plate has a thickness of 2 mm, the second convex rib has a thickness of 1 mm, and the Cr volatilization prevention coating on the surface of the second convex rib has a thickness of about 2.5 mm;

[0124] Between two battery cells, the anode side connecting plate and the cathode side connecting plate adopt a connecting plate assembly, and convex ribs and fluid grooves are respectively arranged on both sides of the connecting plate assembly. The two sides of the connecting plate assembly are divided into the anode side and the cathode side. The thickness of the connecting plate assembly is 4mm, and the thickness of the convex ribs on both sides is 1mm respectively.

[0125] (1.2.3) The electrolyte layer includes a three-layer structure of BCSCuO (anode barrier layer) / SDC (core layer) / PSDC (cathode modification layer), BaCe 0.8 Sm 0.19 Cu 0.1 O3(BCSCuO) is connected to the anode functional layer, Ce 0.8 (Sm 0.5 Pr 0.5 ) 0.2 O 1.9 (PSDC) is connected to the cathode functional layer, wherein the thicknesses of BCSCuO, SDC, and PSDC are approximately 10 μm, 150 μm, and 10 μm, respectively;

[0126] (1.2.4) The anode functional layer includes NiO-BCSCuO, with a thickness of 15 μm, NiO and BaCe 0.8 Sm 0.19 Cu 0.1 The mass ratio of O3(BCSCuO) is 54:46;

[0127] (1.2.5) The cathode functional layer includes LSCF (La 0.6 Sr 0.4 Fe0.8 Co 0.2 O3)-SDC, thickness 15μm, mass ratio of LSCF to SDC is 60:40.

[0128] (1.3) Gas pipeline 1: raw gas inlet pipeline, first flow divider, anode current collector, anode exhaust pipeline, the raw gas inlet pipeline passes the raw gas through the first flow divider to the anode of the solid oxide fuel cell unit through the first fluid groove of the anode side connecting plate;

[0129] The raw gas inlet pipeline extends along the central axis of the battery box, with one end passing through the top of the battery box upwards and the other end communicating with the first diverter at the bottom of the battery box; the anode exhaust pipeline is stacked on the outer periphery of the raw gas inlet pipeline, with one end communicating with the anode current collector at the bottom of the battery box and the other end passing through the battery box from the exhaust port on the battery box wall; the anode exhaust passes into the anode exhaust pipeline through the anode current collector, exchanges heat with the raw gas in the raw gas inlet pipeline, and is then discharged from the exhaust port; four of the battery groups are arranged in the space around the raw gas inlet pipeline; the stacking surface of the anode exhaust pipeline and the raw gas inlet pipeline is a corrugated heat exchange structure.

[0130] (1.4) Gas pipeline 2: air intake pipeline, second flow divider, cathode current collector, cathode exhaust pipeline, the air intake pipeline passes the air through the second flow divider through the second fluid groove of the cathode side connecting plate into the cathode of the solid oxide fuel cell unit; the raw gas and air are arranged to flow in the same direction;

[0131] The cathode exhaust duct and the air intake duct are stacked on the inner wall of the battery box, and the cathode exhaust duct passes through the battery box from the exhaust port; the cathode exhaust passes into the cathode exhaust duct through the cathode current collector, exchanges heat with the air in the air intake duct, and is discharged from the exhaust port; the stacked surface of the cathode exhaust duct and the air intake duct is a corrugated heat exchange structure.

[0132] (1.5) an induction heating coil, arranged around the columnar structure of each battery pack, wherein the induction heating coil is connected to a generator of the gas turbine power generation system;

[0133] (1.6) A cooling unit, including a blower, for supplying air to the battery pack during shutdown operation to cool the battery stack to below 600°C at a rate of about 2.0°C / min to reduce or substantially avoid anode oxidation in a high temperature oxidizing environment.

[0134] 2. Gas turbine power generation system, including:

[0135] (2.1) an air inlet, using an air splitter to split the air entering the air inlet into a first air flow and a second air flow, the first air flow entering the combustion chamber from the first air inlet, and the second air flow exchanging heat with the air outlet pipe of the steam turbine and then connected to the air inlet pipe of the solid oxide fuel cell system; wherein the air introduced above is actually pure oxygen obtained from the air separation device;

[0136] (2.2) a combustion chamber, comprising a first air inlet, a second air inlet, a third air inlet and a steam outlet, wherein the first air inlet is connected to the air inlet, the second air inlet is connected to the anode exhaust pipe of the solid oxide fuel cell system, the third air inlet is connected to the cathode exhaust pipe, and the steam outlet is connected to the steam turbine;

[0137] (2.3) a steam turbine, connected to the steam outlet of the combustion chamber, with a transmission shaft connected to the generator, and an air outlet pipe (between 470°C and 550°C) capable of exchanging heat with the second air flow diverted from the air inlet;

[0138] 3. Coal gasification system, including:

[0139] (3.1) A water-coal slurry preparation unit, wherein the feed port is connected to the water inlet and the raw coal inlet, and the discharge port is connected to the gasifier. The raw coal and water are ground and slurried in this unit to obtain water-coal slurry, which is then sent to the gasifier through the discharge port;

[0140] (3.2) Gasifier, where the water-coal slurry reacts with the pure oxygen obtained from the air separation unit to produce 800-900°C crude high-temperature synthesis gas. The main components of the crude high-temperature synthesis gas include H2, CO, CO2, CH4, H2S and water vapor. The crude high-temperature synthesis gas is cooled to below 100°C by heat exchange with the downstream purified raw gas and then enters the synthesis gas purification system, eliminating the need for an external cooling system;

[0141] 4. Synthesis gas purification system, including:

[0142] (4.1) The dust removal unit uses a bag dust collector to cool and remove dust from the crude high-temperature synthesis gas, reducing the particulate matter content in the crude high-temperature synthesis gas to 80 mg / Nm 3 The following: The dedusted synthesis gas enters the water scrubber for treatment;

[0143] (4.2) Desulfurization unit and fine desulfurization unit, the total sulfur content after treatment is less than 0.3ppm; the desulfurization unit and fine desulfurization unit are connected to the sulfur recovery unit;

[0144] (4.3) Heavy metal removal unit, using activated carbon to further remove heavy metals such as mercury from the synthesis gas to obtain high-quality raw gas with a mercury content of less than 0.01 mg / Nm 3 ;

[0145] The purified raw gas is heated to about 400-550°C by heat exchange with the aforementioned 800-900°C high-temperature crude synthesis gas, and then fed into the raw gas inlet pipeline of the solid oxide fuel cell system;

[0146] 5. An air separation unit, wherein the oxygen obtained after the air passes through the air separation unit can be respectively introduced into the gasifier of the coal gasification system and the air inlet of the gas turbine power generation system (wherein the second air flow enters the air inlet duct of the solid oxide fuel cell system);

[0147] 6. Control system, including: temperature sensors and several switches, valve control units, etc., to monitor the various component systems of the combined power generation equipment, detect the temperature of each battery stack and the temperature of the induction heating coil through temperature sensors, and control the operation of the solid oxide fuel cell system, fuel turbine power generation system, coal gasification system and synthesis gas purification system.

[0148] The combined power generation method comprises the following steps:

[0149] A. Raw gas preparation process:

[0150] (1) Coal gasification process: The raw coal and water are ground and slurried in the water-coal slurry preparation unit and then enter the gasifier. The gasification reaction produces crude high-temperature syngas at about 800-900°C;

[0151] (2) Synthesis gas purification process: The syngas is subjected to dust removal to remove particulate matter, the sulfur concentration is reduced in the desulfurization unit and fine desulfurization unit, and heavy metals such as mercury are removed by activated carbon in the heavy metal removal unit to obtain raw gas;

[0152] (3) Heat exchange and temperature raising process: After the raw gas and the high-temperature synthesis gas (about 800-900° C.) obtained in step (1) are heat exchanged and heated, the high-temperature raw gas (about 400-550° C.) enters the raw gas inlet pipeline, and the synthesis gas (about 100° C. or less) after heat exchange enters the synthesis gas purification process in step (2);

[0153] B. During the startup phase, the battery pack is preheated using high-temperature raw gas, and in particular, an induction heating coil arranged around each battery pack is used to quickly heat up the battery pack for startup, including:

[0154] Step 1: The high-temperature raw gas preheats the battery pack through the raw gas intake pipe, and then enters the combustion chamber of the gas turbine power generation system through the anode exhaust pipe, and burns with the first air flow (pure oxygen obtained after passing through the air separation device) introduced into the air inlet in the combustion chamber to obtain high-temperature steam. The high-temperature steam enters the steam turbine from the steam outlet, drives the steam turbine to rotate, and drives the generator to output AC power through the transmission shaft;

[0155] Step 2: The generator supplies AC power to the induction heating coil to induction heat the conductive material in the battery pack. The high-temperature raw gas preheating and induction heating time are about 5 minutes in total to raise the temperature of the battery pack to 700±10℃;

[0156] Step three, supply air to the cathode of the solid oxide fuel cell unit through the air intake pipe to enter the normal operation stage. The air introduced here is provided by the second air flow (about 400-450°C, pure oxygen is obtained after passing through the air separation unit) after the temperature of the battery pack reaches the operating temperature; wherein, after the combined power generation equipment reaches the preset normal operating temperature, the generator stops outputting AC power to the induction heating coil, and switches the AC power generated by the generator to power the electrical components required for the coal gasification process and the synthesis gas purification process; cooling water is introduced into the hollow tube of the induction heating coil to cool it down and prevent the induction heating coil from being damaged, and the water after heat exchange is introduced into the water-coal slurry preparation unit of the coal gasification process.

[0157] C. Stabilizing the combined power generation process:

[0158] S1, the high-temperature raw gas (about 400-550°C) is heat-exchanged with the high-temperature anode exhaust gas again (about 600-700°C) and then respectively introduced into the anode of the solid oxide fuel cell unit through the raw gas intake pipe and the first splitter, and the preheated second air flow (about 400-450°C) is heat-exchanged with the high-temperature cathode exhaust gas (about 600-700°C) and then respectively introduced into the cathode of the solid oxide fuel cell unit through the air intake pipe and the second splitter, and the raw gas and air react chemically in the solid oxide fuel cell unit to output electrical energy;

[0159] S2, the high-temperature anode exhaust gas is passed into the anode exhaust pipe through the anode current collector and heat-exchanged with the raw gas inlet pipe; the high-temperature cathode exhaust gas is passed into the cathode exhaust pipe through the cathode current collector and heat-exchanged with the air inlet pipe;

[0160] S3. The anode exhaust and cathode exhaust after heat exchange enter the combustion chamber of the gas turbine power generation system, and burn with the air introduced from the air inlet in the combustion chamber to obtain high-temperature steam. The high-temperature steam enters the steam turbine from the steam outlet, drives the steam turbine to rotate, and drives the generator to output AC power through the transmission shaft.

[0161] When the combined power generation equipment is in shutdown operation, the blower of the cooling unit provides air to the battery pack to cool the battery stack to below 600°C at a rate of about 2.0°C / min to reduce or substantially avoid anode oxidation in a high temperature oxidizing environment.

[0162] The optimized integration of the combined power generation equipment of the solid oxide fuel cell based on this embodiment can provide a maximum electrical power of about 25 kW and a net electrical efficiency of 76%, which can achieve a higher net electrical efficiency than the 55-62% of the traditional ordinary natural gas combined cycle and the 55-60% of the Alam cycle.

[0163] Example 2

[0164] The main difference between the combined power generation equipment based on solid oxide fuel cells in this embodiment and that in embodiment 1 is that the composition of the solid oxide fuel cell system is different, specifically including:

[0165] 1. Solid oxide fuel cell system, comprising:

[0166] (1.1) Columnar battery box;

[0167] (1.2) A plurality of battery packs, housed in the columnar battery box, including 12 battery packs, symmetrically distributed around the raw gas inlet pipe in a 4+8 double-layer surround form in the columnar battery box, each battery pack being formed into a columnar structure by stacking 50 solid oxide fuel cell units;

[0168] Each battery cell includes a stacked anode side connecting plate, an anode functional layer, an electrolyte layer, a cathode functional layer and a cathode side connecting plate, specifically including:

[0169] (1.2.1) The anode side connecting plate has a first convex rib and a first fluid groove on the side facing the anode, and a Cr volatilization prevention coating is provided at least on the surface of the first convex rib; the thickness of the anode side connecting plate is 2 mm, the thickness of the first convex rib is 1 mm, and the thickness of the Cr volatilization prevention coating on the surface of the first convex rib is about 2.5 mm;

[0170] (1.2.2) The cathode side connecting plate has a second convex rib and a second fluid groove on the side facing the cathode, and a Cr volatilization prevention coating is provided at least on the surface of the second convex rib; the cathode side connecting plate has a thickness of 2 mm, the second convex rib has a thickness of 1 mm, and the Cr volatilization prevention coating on the surface of the second convex rib has a thickness of about 2.5 mm;

[0171] Between two battery cells, the anode side connecting plate and the cathode side connecting plate adopt a connecting plate assembly, and convex ribs and fluid grooves are respectively arranged on both sides of the connecting plate assembly. The two sides of the connecting plate assembly are divided into the anode side and the cathode side. The thickness of the connecting plate assembly is 4mm, and the thickness of the convex ribs on both sides is 1mm respectively.

[0172] (1.2.3) The electrolyte layer includes a three-layer structure of BCSCuO (anode barrier layer) / SDC (core layer) / PSDC (cathode modification layer), BaCe 0.8 Sm 0.19 Cu0.1 O3(BCSCuO) is connected to the anode functional layer, Ce 0.8 (Sm 0.5 Pr 0.5 ) 0.2 O 1.9 (PSDC) is connected to the cathode functional layer, wherein the thicknesses of BCSCuO, SDC, and PSDC are approximately 10 μm, 85 μm, and 5 μm, respectively;

[0173] (1.2.4) The anode functional layer includes NiO-BCSCuO, with a thickness of 15 μm, NiO and BaCe 0.8 Sm 0.19 Cu 0.1 The mass ratio of O3(BCSCuO) is 54:46;

[0174] (1.2.5) The cathode functional layer includes LSM (La 0.8 Sr 0.2 ) 0.98 MnO3)-SDC, thickness 15μm, mass ratio of LSM to SDC is 60:40.

[0175] (1.3) Gas pipeline 1: raw gas inlet pipeline, first flow divider, anode current collector, anode exhaust pipeline, the raw gas inlet pipeline passes the raw gas through the first flow divider to the anode of the solid oxide fuel cell unit through the first fluid groove of the anode side connecting plate;

[0176] The raw gas inlet pipeline extends along the central axis of the battery box, with one end passing through the top of the battery box upwards and the other end communicating with the first diverter at the bottom of the battery box; the anode exhaust pipeline is stacked on the outer periphery of the raw gas inlet pipeline, with one end communicating with the anode current collector at the bottom of the battery box and the other end passing through the battery box from the exhaust port on the battery box wall; the anode exhaust passes into the anode exhaust pipeline through the anode current collector, exchanges heat with the raw gas in the raw gas inlet pipeline, and is then discharged from the exhaust port; four of the battery groups are arranged in the space around the raw gas inlet pipeline; the stacking surface of the anode exhaust pipeline and the raw gas inlet pipeline is a corrugated heat exchange structure.

[0177] (1.4) Gas pipeline 2: air intake pipeline, second flow divider, cathode current collector, cathode exhaust pipeline, the air intake pipeline passes the air through the second flow divider through the second fluid groove of the cathode side connecting plate into the cathode of the solid oxide fuel cell unit;

[0178] The cathode exhaust duct and the air intake duct are stacked on the inner wall of the battery box, and the cathode exhaust duct passes through the battery box from the exhaust port; the cathode exhaust passes into the cathode exhaust duct through the cathode current collector, exchanges heat with the air in the air intake duct, and is discharged from the exhaust port; the stacked surface of the cathode exhaust duct and the air intake duct is a corrugated heat exchange structure.

[0179] (1.5) an induction heating coil, arranged around the columnar structure of each battery pack, wherein the induction heating coil is connected to a generator of the gas turbine power generation system;

[0180] (1.6) A cooling unit, including a blower, for supplying air to the battery pack during shutdown operation to cool the battery stack to below 600°C at a rate of about 2.0°C / min to reduce or substantially avoid anode oxidation in a high temperature oxidizing environment.

[0181] The combined power generation is carried out in a manner basically the same as in Example 1. The optimized integration of the combined power generation equipment based on the solid oxide fuel cell of this embodiment can provide a maximum electric power of about 110 kW and a net electrical efficiency of 78%, which can achieve a higher net electrical efficiency than the 55-62% of the traditional ordinary natural gas combined cycle and the 55-60% of the Alam cycle.

[0182] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they are aware of the basic creative concepts. Therefore, the present invention is intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention. Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention.

Claims

1. A combined power generation device based on solid oxide fuel cells, characterized in that: include: Solid oxide fuel cell systems and fuel turbine power generation systems; The solid oxide fuel cell system comprises a cylindrical battery box, and a battery pack having a plurality of solid oxide fuel cell units, a raw gas intake pipe, an air intake pipe, a first flow divider, a second flow divider, an anode current collector, an anode exhaust pipe, a cathode current collector and a cathode exhaust pipe housed in the cylindrical battery box; The raw gas inlet pipeline passes the raw gas into the anode of the battery unit through the first splitter, and the air inlet pipeline passes the air into the cathode of the battery unit through the second splitter; The anode exhaust of the battery unit is passed into the anode exhaust pipe through the anode current collector, and the cathode exhaust is passed into the cathode exhaust pipe through the cathode current collector. The anode exhaust pipe is connected to the raw gas intake pipe for heat exchange, and the cathode exhaust pipe is connected to the air intake pipe for heat exchange; The gas turbine power generation system includes an air inlet, a combustion chamber, a steam turbine and a generator; The combustion chamber includes a first air inlet, a second air inlet, a third air inlet and a steam outlet. The first air inlet is connected to the air intake, the second air inlet is connected to the anode exhaust pipe of the solid oxide fuel cell system, the third air inlet is connected to the cathode exhaust pipe, and the steam outlet is connected to the steam turbine. The steam turbine and the generator are connected by a transmission shaft.

2. The combined power generation device according to claim 1, characterized in that: The gas turbine power generation system also includes an air splitter, which splits the air entering the air inlet into a first air flow and a second air flow. The first air flow enters the combustion chamber from the first air inlet, and the second air flow is connected to the air intake duct of the solid oxide fuel cell system after heat exchange with the outlet pipe of the steam turbine.

3. The combined power generation equipment according to claim 1 or 2, characterized in that: The raw gas inlet pipeline extends along the central axis of the battery box, the inlet end of the raw gas inlet pipeline passes through the top of the battery box upward, and the outlet end is connected to the first diverter at the bottom of the battery box; The anode exhaust pipe is stacked on the outer periphery of the raw gas intake pipe, the intake end of the raw gas intake pipe is connected to the anode current collector at the bottom of the battery box, and the outlet end passes through the battery box through the exhaust port on the battery box wall; The cathode exhaust duct and the air intake duct are stacked and arranged on the inner wall surface of the battery box, and the cathode exhaust duct passes through the battery box through the exhaust port.

4. The combined power generation device according to claim 3, characterized in that: Arrange a plurality of the battery packs in the space around the raw gas inlet pipe, each battery pack being formed into a columnar structure by stacking a plurality of battery units; The battery cell includes a stacked anode-side connecting plate, an anode functional layer, an electrolyte layer, a cathode functional layer, and a cathode-side connecting plate; Induction heating coils are arranged around the columnar structures of each battery pack, and the induction heating coils are connected to the generator of the gas turbine power generation system.

5. The combined power generation equipment according to claim 4, characterized in that: The battery cell further comprises at least one of the following: (1) The anode-side connecting plate has a first convex rib and a first fluid groove at least on the side facing the anode, and a Cr volatilization-proof coating is provided on at least the surface of the first convex rib; (2) The cathode-side connecting plate has a second convex rib and a second fluid groove at least on the side facing the cathode, and a Cr volatilization-proof coating is provided on at least the surface of the second convex rib; (3) The electrolyte layer includes a three-layer structure of BCSCuO / SDC / PSDC, wherein BCSCuO is connected to the anode functional layer, and PSDC is connected to the cathode functional layer; (4) The anode functional layer comprises NiO-BCSCuO; (5) The cathode functional layer comprises LSM-SDC or LSCF-SDC.

6. The combined power generation equipment according to claim 4, characterized in that: The induction heating coil is a hollow tube made of a heat-resistant metal material, and the outer surface of the hollow tube is coated with a metal oxide barrier layer.

7. The combined power generation device according to any one of claims 4 to 6, characterized in that: The combined power generation equipment also includes a coal gasification system and a synthesis gas purification system; The coal gasification system includes a water-coal slurry preparation unit and a gasifier to produce synthesis gas; The synthesis gas purification system includes a dust removal unit and a desulfurization unit, which purify the synthesis gas into raw gas. The raw gas enters the raw gas inlet pipeline after heat exchange with the synthesis gas and temperature rises.

8. A combined power generation method using the combined power generation equipment according to any one of claims 1 to 7, characterized in that: The steps include: S1, the raw gas is introduced into the anode of the solid oxide fuel cell unit through the raw gas inlet pipeline and the first splitter, and the air is introduced into the cathode of the solid oxide fuel cell unit through the air inlet pipeline and the second splitter, and the raw gas and air react chemically in the solid oxide fuel cell unit to output electrical energy; S2, the high-temperature anode exhaust gas is passed into the anode exhaust pipe through the anode current collector and heat-exchanged with the raw gas inlet pipe; the high-temperature cathode exhaust gas is passed into the cathode exhaust pipe through the cathode current collector and heat-exchanged with the air inlet pipe; S3. The anode exhaust and cathode exhaust after heat exchange enter the combustion chamber of the gas turbine power generation system, and burn with the air introduced from the air inlet in the combustion chamber to obtain high-temperature steam. The high-temperature steam enters the steam turbine from the steam outlet, drives the steam turbine to rotate, and drives the generator to output AC power through the transmission shaft.

9. The combined power generation method according to claim 8, characterized in that: The raw gas is prepared by the following steps: (1) Coal gasification process: Raw coal and water are ground and slurried in the water-coal slurry preparation unit before entering the gasifier, where the gasification reaction produces high-temperature syngas; (2) Synthesis gas purification process: Synthesis gas is dedusted to remove particulate matter, and the sulfur concentration is reduced in the desulfurization unit to obtain raw gas; (3) Heat exchange and temperature raising process: The raw gas is heated by heat exchange with the high-temperature synthesis gas obtained in step (1) and then enters the raw gas inlet pipeline. The synthesis gas after heat exchange enters the synthesis gas purification process in step (2).

10. The combined power generation method according to claim 9, characterized in that: The battery packs are quickly heated and started using induction heating coils arranged around each battery pack, including the following steps: Step 1: The high-temperature raw gas preheats the battery pack through the raw gas intake pipe, and then enters the combustion chamber of the gas turbine power generation system through the anode exhaust pipe, and burns with the air introduced into the air inlet in the combustion chamber to obtain high-temperature steam. The high-temperature steam enters the steam turbine from the steam outlet, drives the steam turbine to rotate, and drives the generator to output AC power through the transmission shaft; Step 2, the generator supplies power to the induction heating coil connected thereto, performs induction heating on the battery pack, and raises the temperature of the battery pack to 600° C. to 750° C. within 10 minutes; Step 3: supply air to the cathode of the solid oxide fuel cell unit through the air intake pipe, and proceed to the above-mentioned step S1.

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