CN104112866B - The burning of a kind of fuel cell system is reformed and is premixed integrated apparatus - Google Patents

Abstract

The invention discloses a combustion reforming and premixing integrated device for a fuel cell system. Specifically, the device is connected with a burner, a reforming chamber, and a vaporization premixing chamber from bottom to top, and the outer wall of the flue gas expansion chamber of the burner simultaneously constitutes the outer wall of the reforming chamber and the vaporization premixing chamber . The high-quality heat of the combustion chamber of the present invention is firstly used for reforming reaction heat supply, and the remaining heat is further used for preheating methane and vaporizing water, realizing cascade utilization of energy and maximizing system efficiency.

Description

Combustion reforming premixing integrated device for fuel cell system

technical field

The invention relates to an integrated combustion reforming premixing device, in particular to a combustion reforming premixing integrated device used in a fuel cell system.

Background technique

Fuel cells can efficiently and environmentally friendly convert the chemical energy stored in the fuel into electric energy isothermally. Hydrogen is the best fuel for fuel cells. However, if only hydrogen is used as fuel, it will limit the industrialization and scale of fuel cell systems. How to convert fuels such as natural gas into hydrogen is crucial.

The industrial steam reforming hydrogen production technology (CH ₄ +H ₂ O→CO+3H ₂ ) has been quite mature, but this large-scale hydrogen production technology cannot meet the requirements of compact and miniaturized fuel cell systems.

Due to the low hydrogen demand of the fuel cell system, it is impossible to simply reduce the design parameters of the mature large-scale hydrogen production process. Therefore, there is an urgent need in this field to develop a small integrated steam reforming device suitable for the fuel cell system.

Contents of the invention

The invention provides a reforming device integrating combustion, reforming, vaporization, preheating and mixing functions for a fuel cell system.

The first aspect of the present invention provides an integrated combustion reforming and premixing device for a fuel cell system. The device is connected with a burner, a reforming chamber and a vaporization premixing chamber from bottom to top.

In another preferred example, the burner further includes a flue gas expansion chamber, and the flue gas expansion chamber is arranged at the upper part of the burner, extends upward and surrounds the reforming chamber and the vaporization premixing chamber.

In another preferred example, the shell of the flue gas expansion chamber forms a closed shell of the reforming chamber and the vaporization premixing chamber.

In another preferred example, the flue gas outlet of the flue gas expansion chamber is located at the upper part or the top of the flue gas expansion chamber.

In another preferred example, the flue gas expansion chamber (or its shell) is made of stainless steel or alloy.

In another preferred example, the size of the flue gas expansion chamber is 90-320mm, preferably 100-305mm, more preferably 133-245mm.

In another preferred example, the burner further includes a fuel inlet, an air inlet and a fuel-air mixing chamber, and the fuel inlet, the air inlet and the fuel-air mixing chamber communicate with the smoke expansion chamber.

In another preferred example, the burner further includes a spark plug, a flame disc and/or a flue gas outlet.

In another preferred example, the burner further includes an explosion-proof switch and a gas flow meter.

In another preferred example, the pipe diameter of the fuel inlet is 5-20 mm, more preferably 10-15 mm.

In another preferred example, the pipe diameter of the air inlet is 5-40mm, more preferably 10-30mm.

In another preferred example, the fuel-air mixing chamber includes a primary mixing chamber and a final mixing chamber, and the burner end of the fuel inlet extends into the primary mixing chamber.

In another preferred example, the shapes of the primary mixing chamber and the final mixing chamber include a conical shape or a cylindrical shape.

In another preferred example, the wall of the burner end tube of the fuel inlet is provided with porous openings.

In another preferred example, the arrangement of the porous openings is evenly arranged along the circumference.

In another preferred example, a detachable connection device is provided between the primary mixing chamber and the final mixing chamber.

In another preferred example, the detachable connection device includes a flange connection.

In another preferred example, the vaporization premixing chamber includes a raw material inlet, a variable diameter premixing coil, a mixing buffer tank, and a mixed gas outlet, wherein the raw material inlet, variable diameter premixing coil, mixing buffer tank And the mixed gas outlets communicate with each other in sequence.

In another preferred example, the vaporization premixing chamber includes a raw material inlet, a variable diameter premixing coil, a mixing buffer tank, and a mixed gas outlet, wherein the raw material inlet, variable diameter premixing coil, mixing buffer tank And the mixed gas outlets communicate with each other in sequence.

In another preferred example, the variable-diameter premixing coil is coiled and arranged outside the mixing buffer tank.

In another preferred example, the mixing buffer tank is provided with heat-conducting materials.

In another preferred example, the heat conducting material includes honeycomb metal, mesh metal, porous medium material, or a combination thereof.

In another preferred example, the raw material inlet includes a water inlet and a methane inlet.

In another preferred example, the diameter of the variable-diameter premixing coil increases from the inlet-outlet direction; and/or

The variable-diameter premixing coil includes at least two diameters.

In another preferred example, the variable-diameter premixing coil includes a thin-diameter coil and a thick-diameter coil.

In another preferred example, the thin-diameter coil is wrapped around the periphery of the thick-diameter coil.

In another preferred example, the reforming chamber includes a mixed gas outlet, a reforming tube, and a reformed product outlet, and the mixed gas outlet, reforming tubes, and reformed product outlet are connected to each other in sequence. connected.

In another preferred example, a gas splitter plate is provided between the mixed gas outlet and the reforming tube, wherein the gas splitter plate is used to collect the mixed gas flowing out from the mixing buffer tank, and transfer the mixed gas to the The mixed gas is discharged into the reforming column; and/or

A gas collecting plate is provided between the reforming tubes and the gas outlet of the reformed product, wherein the gas collecting plate is used to collect the reformed gas in the reforming tubes and transfer the reformed The gas is discharged into the reformate gas outlet.

In another preferred example, the reforming array tubes are uniformly arranged around the centerlines of the diverter tray and the collector tray.

In another preferred example, the number of reforming tubes is n, where n=a positive integer of 2-16; and/or

In another preferred example, the wall of the reforming tube is provided with an external thread structure.

In another preferred example, n through holes are respectively set on the gas distribution plate or the gas collection plate, n is a positive integer of 2-16, and the through holes of the gas distribution plate and the gas collection plate are determined by the The reforming tubes are connected.

In another preferred example, the reforming chamber is also provided with a temperature controller.

The second aspect of the present invention provides a fuel cell system, which includes the integrated combustion reforming premixing device as described in the first aspect of the present invention, a fuel cell, an air compressor, a water separator and a water tank , metering pumps, various valve control and temperature control devices.

It should be understood that within the scope of the present invention, the above-mentioned technical features of the present invention and the technical features specifically described in the following (such as embodiments) can be combined with each other to form new or preferred technical solutions. Due to space limitations, we will not repeat them here.

Description of drawings

Fig. 1 is a schematic structural diagram of a combustion reforming vaporization preheating integrated device for a fuel cell system;

Fig. 2 is a schematic diagram of the internal structure of the integrated combustion, reforming, vaporization and preheating device;

Fig. 3 is a schematic diagram of the wall structure of the reforming pipe with the external thread structure.

Among them, 1-burner, 2-reformer, 3-gasification preheating mixing device, 4-fuel inlet, 5-air inlet, 6-initial mixing chamber, 7-flange, 8-final mixing chamber, 9- Flame plate, 10-spark plug, 11-bolt, 12-reformate gas outlet, 13-gas collecting plate, 14-flue gas expansion chamber, 15-external thread structure reforming tube, 16-gas distribution plate, 17 - Filled with porous metal material mixing buffer tank, 18- thin diameter coil, 19- thick diameter coil, 20- combustion flue gas outlet, 21- water inlet, 22- natural gas inlet, 23- mixed gas outlet, 24, 25-thermocouple, 26-anti-riot switch interface.

detailed description

After extensive and in-depth research, the present inventor first connected and combined the burner, reforming chamber and vaporization premixing chamber in the fuel cell system from bottom to top, so that the reforming and vaporization premixing chamber was located in the flue gas of the burner The inside of the expansion chamber makes full use of the heat in the burner, that is, the flue gas generated by burning fuel heats the reformer to reach the temperature required for the reaction, and the remaining heat of the flue gas used for the reforming reaction is supplied to water vaporization and natural gas preheating , In the vaporization preheating mixing device, the water is vaporized into water vapor, and the natural gas is preheated and mixed with water vapor before being supplied to the reformer. The device of the invention utilizes waste heat step by step, which is beneficial to improving system integration and overall system efficiency.

burner

In the present invention, the burner is used to burn the anode off-gas or other fuel gas of the fuel cell. After the anode tail gas or fuel gas is combusted, its heat is used in steps for reforming reaction and premixing of reforming reaction raw materials. Typically, the fuel gas includes natural gas.

The burner of the present invention includes a flue gas fuel inlet, an air inlet and a fuel-air mixing chamber, the fuel inlet and the air inlet communicate with the fuel-air mixing chamber, and the pipeline used for the fuel inlet extends into the fuel-air inside the mixing chamber.

Wherein, the fuel-air mixing chamber may further include an initial mixing chamber and a final mixing chamber. In order to fully mix fuel and air, the burner end of the fuel inlet is located in the primary mixing chamber, and the tube wall is provided with porous openings, and the arrangement of the porous openings is evenly arranged along the circumference. When air and fuel are passed in, the porous opening can make the fuel mix with the air at a certain pressure, so as to carry out sufficient combustion.

The diameter of the pipeline that can be used for the fuel inlet or the air inlet of the present invention is not particularly limited, and different designs can be made according to the size of the integrated combustion reforming premixing device and the amount of fuel and air required. Usually, the pipe diameter of the fuel inlet is 5-20mm, preferably 10-15mm; the pipe diameter of the air inlet is 5-40mm, preferably 10-30mm.

In the present invention, the burner is provided with a flue gas expansion chamber, and the flue gas expansion chamber is arranged at the upper part of the burner, extends upwards and surrounds the reforming chamber and the vaporization premixing chamber. The top of the flue gas expansion chamber is also provided with a flue gas outlet for discharging the remaining flue gas.

The material that can be used for the flue gas expansion chamber (or its shell) of the present invention is not particularly limited, and can be any material that can withstand high temperatures. Usually, the flue gas expansion chamber (or its shell) is made of stainless steel or alloy.

The diameter of the flue gas expansion cavity of the present invention is not particularly limited, as long as it can cover or surround the reformer and vaporization preheating cavity, or it can be designed or manufactured according to the size of the combustion reforming premixing integrated device. Usually, the size (outer diameter) of the flue gas expansion cavity is 90-320 mm, preferably 100-305 mm, more preferably 133-245 mm.

In another preferred example, the fuel and air enter the initial mixing chamber for preliminary mixing, and then enter the final mixing chamber to mix evenly, and burn at the flame plate through an electric spark plug to generate smoke, and the smoke is ejected into the smoke Gas expansion chamber, when the shell of the flue gas expansion chamber forms the closed shell of the reforming chamber and the vaporization premixing chamber, the flue gas is encapsulated in the reforming chamber immediately above the burner and the vaporization preheating chamber at the top In the cavity, the pressure is diffused and the speed is reduced, thereby heating the reforming cavity and the vaporization premixing cavity located on the upper part of the burner.

In addition, the burner of the present invention also includes a spark plug, a flame disc, a flue gas outlet, an explosion-proof switch and/or a gas flow meter. The burner feed and initial mixing chamber are separated from the combustion flame plate and final mixing chamber, and are connected by flanges, which are flexible in installation and easy to disassemble and replace. In order to prevent the burner from becoming a high-pressure vessel and other dangerous situations, an explosion-proof switch is installed to ensure safe and reliable operation. At the same time, the combustion power is controlled by controlling the fuel flow rate of 1-35 l/min through the flow meter, and the position and height of the combustion flame are controlled by adjusting the ratio of natural gas and air to 10-20.

Vaporization premix chamber

In the present invention, the vaporization premixing chamber includes a raw material inlet, a variable-diameter premixing coil, a mixing buffer tank and a mixed gas outlet, and the raw material inlet, a variable-diameter premixing coil, a mixing buffer tank and a mixed gas outlet are connected to each other in sequence. connected.

Wherein, the raw material inlet includes a water inlet and a methane inlet; the variable-diameter premixing coil is coiled outside the mixing buffer tank, and the variable-diameter premixing coil includes at least two diameters, the diameter of which varies from the inlet to the outlet. thicken. Generally, the variable-diameter premixing coils include thin-diameter coils and thick-diameter coils.

The pipe diameter and fuel flow rate of the variable-diameter premixing coil that can be used in the present invention are not particularly limited, and can be designed or manufactured according to the size of the combustion reforming premixing integrated device. Usually, the thin-diameter coil is wrapped around the periphery of the thick-diameter coil, and the diameter of the thin-diameter coil is 2-10mm, more preferably, 4-6mm, and the water flow rate is 1-160g/min; The diameter of the pipe diameter coil is 6-20mm, more preferably, 8-16mm. When methane and liquid water enter the thin pipe diameter coil through the raw material inlet, they are heated by the heat provided by the burner, and the liquid water is gradually vaporized into Water vapor, and after volume expansion, enters a coil with a larger diameter. Certainly, the diameter of the variable-diameter premixing coil can also be gradual or multi-stage, both of which can be used for heating liquid water.

In the present invention, the mixing buffer tank is connected to the far end of the variable-diameter premixing coil, and its interior can be filled with heat-conducting material to buffer the mixed gas and further heat it. The heat conduction material and size that can be used in the mixing buffer tank of the present invention are not particularly limited, wherein the heat conduction material can be any material that conducts heat quickly and can form an airflow buffering effect, such as metal or other heat conduction medium, preferably, the metal or The heat-conducting medium material is honeycomb, mesh or porous; the size of the mixing buffer tank can be designed or manufactured according to the size of the combustion reforming premixing integrated device, such as 50-102mm.

The raw gas that can be used in the vaporization premixing chamber of the present invention includes methane or natural gas. Methane or natural gas can pass through the buffer tank directly, or lead to the variable diameter coil together with the water inlet. In another preferred example, the raw material gas can directly enter the mixing buffer tank, and after being fully mixed with water vapor, enter the reformer for reforming reaction.

In the present invention, the ratio of raw gas and water vapor can be adjusted according to the different needs of the water-carbon ratio of the reforming reactant (the molar ratio of water vapor to natural gas is between 1 and 5) through the gas source or flow meter. In another preferred example, the combustion reforming vaporization premixing device can be used in a fuel cell system to reform natural gas to generate hydrogen for fuel cell power generation.

reforming chamber

In the present invention, the reforming chamber includes a mixed gas outlet, reforming tubes, and reformed product gas outlets, and the mixed gas outlet, reforming tubes, and reformed product gas outlets communicate with each other in sequence.

Wherein, a gas splitter plate is provided between the mixed gas outlet and the reforming tube, wherein the gas splitter plate is used to collect the mixed gas flowing out from the mixing buffer tank, and discharge the mixed gas into the heavy full array of tubes; and/or

A gas collecting plate is provided between the reforming tubes and the gas outlet of the reformed product, and the gas collecting plate is used to collect the reformed gas in the reforming tubes and discharge the reformed gas into the reformate gas outlet.

In the present invention, n through holes are respectively set on the gas distribution plate or the gas collection plate, n is a positive integer of 2-16, and the through holes of the gas distribution plate and the gas collection plate are reformed by the The tubes are connected. The number of reforming column tubes can be designed according to the through holes of the distribution plate or the collecting plate; in a preferred example, the through holes are evenly distributed on the gas separating plate or collecting plate, and the reforming column The tubes are evenly spaced around the centerline of the diverter and collector pans. Wherein, the number of reforming tubes is n, wherein n=2-16 positive integers. The number of reforming tubes can be 2-26, and in a preferred example, the number of reforming tubes is 6-16

In order to make the heat exchange and reforming reaction of the reformed gas inside the reforming tube more fully, it is preferable to provide an external thread structure on the tube wall of the reforming tube, thereby increasing the heat exchange area of the reformed gas .

The size of the reforming column tubes that can be used in the present invention is not particularly limited, and can include various sizes suitable for the device of the present invention. Usually, its size is 10-50mm*250mm-700mm. More preferably, the reforming column The tube is 18-28*330-465mm.

In the present invention, the upper part of the reforming chamber leads to the premixing chamber, and the mixture gas inlet of water vapor and natural gas is connected through the distributor plate, and the lower part leads to the burner, and the mixture gas inlet is connected with the collecting plate. The mixed gas in the gas distribution plate enters the reforming tubes through the through holes to carry out the reforming reaction, and the reformed product gas generated by the reaction in the reforming tubes is collected through the collecting plate and discharged through the gas outlet.

In addition, the reforming chamber is also equipped with a temperature controller, through which the reaction temperature in the reforming tube can be fed back to control the burning of the inlet fuel of the burner. The mixed gas after the reformation reaction is delivered to the anode of the fuel cell stack for reaction.

fuel cell system

The fuel cell system of the present invention includes the combustion reforming premixing integrated device of the present invention, a fuel cell, an air compressor, a water separator and a water tank, a metering pump, various valve control and temperature control devices.

application

Combustion reforming premixing integrated device of the present invention can be used for small-scale hydrogen production, and can also be used for external reforming of fuel cell system, so there is no problem of hydrogen storage and transportation, as long as the reforming premixing integrated device of fuel cell system Connected to natural gas, it can continuously output electric energy. The system can be used as a portable or distributed fuel cell power generation device with safety, environmental protection, high reliability, compact structure and reasonable arrangement. The fuel cell distributed cogeneration system can provide stable power for network servers, telecommunication equipment, residential quarters, hospitals, banks, etc. in the regional energy network, and at the same time provide cheap heat sources. It has a large market scale and moderate user tolerance, and has good market application prospects and commercial value.

Beneficial effects of the present invention

The invention provides a reforming reaction device for cascade utilization of combustion energy used in fuel cells. The device arranges the flue gas expansion chamber of the burner on the periphery of the reforming chamber and the vaporization premixing chamber, so that the heat energy generated by the combustion chamber passes through the reforming chamber and the water-methane premixing chamber for multiple cascaded heat exchanges. Combustion, vaporization, preheating, mixing, reforming and other functions are integrated in one, and the structure is simple, which can meet the requirements of miniaturization, saves the steam generator, and improves the integration of the device. The high-quality heat of the combustion chamber is first used to heat the peripheral reforming reaction, and the remaining heat is further used to preheat methane and vaporize water, realizing cascade utilization of energy and maximizing system efficiency.

All documents mentioned in this application are incorporated by reference in this application as if each were individually incorporated by reference. In addition, it should be understood that after reading the above teaching content of the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of the present application.

Claims (9)

1. A combustion reforming premixing integrated device for a fuel cell system, characterized in that the device is connected from bottom to top with a burner, a reforming chamber and a vaporization premixing chamber; wherein The reforming chamber includes a mixed gas outlet, reforming tubes and reformed product gas outlets, and the mixed gas outlet, reforming tubes and reformed product gas outlets are connected to each other in sequence; and A gas splitter plate is provided between the mixed gas outlet and the reforming tube, and the gas splitter plate is used to collect the mixed gas flowing out of the mixing buffer tank and discharge the mixed gas into the reforming tube; and / or A gas collecting plate is provided between the reforming tubes and the gas outlet of the reformed product, wherein the gas collecting plate is used to collect the reformed gas in the reforming tubes and transfer the reformed The gas is discharged into the reformate gas outlet. 2. The device according to claim 1, wherein the burner further comprises a flue gas expansion chamber, and the flue gas expansion chamber is arranged on the upper part of the burner, extends upward and surrounds the reforming chamber and Vaporize the premix chamber. 3. The device according to claim 2, wherein the burner further comprises a fuel inlet, an air inlet and a fuel-air mixing chamber, and the fuel inlet, the air inlet and the fuel-air mixing chamber are connected to the The flue gas expansion chambers communicate with each other. 4. The device according to claim 3, wherein the fuel-air mixing chamber comprises a primary mixing chamber and a final mixing chamber, and the burner end of the fuel inlet extends into the primary mixing chamber. 5. The device according to any one of claims 1-4, wherein the vaporization premixing chamber includes a raw material inlet, a variable diameter premixing coil, a mixing buffer tank and a mixed gas outlet, wherein the raw material The inlet, variable-diameter premixing coil, mixing buffer tank and mixed gas outlet communicate with each other in sequence. 6. The device according to claim 5, wherein the diameter of the variable-diameter premixing coil increases from the inlet-outlet direction; and/or The variable-diameter premixing coil includes at least two diameters. 7. The device according to claim 1, characterized in that, the reforming array tubes are evenly arranged around the centerlines of the diverter tray and the collector tray. 8. The device according to claim 1, wherein n through holes are respectively set on the gas distribution plate or the gas collection plate, and n is a positive integer of 2-16, and the gas distribution plate and the gas collection plate The through holes of the flow plate are connected by the reforming tubes. 9. A fuel cell system, characterized in that the fuel cell system comprises the combustion reforming premixing integrated device as claimed in claim 1 and a fuel cell, an air compressor, a water separator and a water tank, a metering pump, Various valve control and temperature control devices.