JP2003120427A - Hybrid system equipped with gas engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide structure capable of preventing occurrence of knocking and back fire, and maintaining high heat efficiency, in separated/extracted hydrogen from a fuel reformer, when reforming hydrocarbon fuel in the fuel reformer. SOLUTION: After reforming hydrocarbon fuel in the fuel reformer 51, hydrogen is separated/extracted from reformed fuel by a hydrogen separating device 56. The hydrogen separated/extracted fuel is supplied into a gas engine body 2. Separated/extracted hydrogen is supplied through a hydrogen pump unit 9 as a fuel of fuel cell 100.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hybrid system equipped with a gas engine in which a hydrocarbon-based fuel is reformed by a fuel reformer and the reformed fuel is supplied to a combustion chamber. . In particular, the present invention relates to measures for improving the thermal efficiency by effectively using the reformed fuel.

[0002]

2. Description of the Related Art Conventionally, as one form of a gas engine, a hydrocarbon-based fuel (C _m H _n ) is reformed by a fuel reformer to obtain a fuel having a large calorific value, thereby improving the thermal efficiency of the engine. It is known to improve the quality.

FIG. 3 is a diagram showing a schematic configuration of a power generation system for generating power by this type of gas engine. As shown in this figure, in the present gas engine, an output shaft a1 extending from the engine body a is connected to a generator b, and the rotational driving force of the output shaft a1 causes the generator b to generate electric power. ing.

The intake system of the gas engine is composed of an air supply system and a fuel supply system, and a mixture of air supplied from the air supply system and fuel supplied from the fuel supply system enters the combustion chamber. The engine body a is supplied and driven.

The air supply system is a supercharger (compressor) c.
And an intercooler d. That is, after the air is compressed by the supercharger c and the air is cooled by the intercooler d, high density air can be supplied toward the combustion chamber. The supercharger c is
It is directly connected to an output shaft f1 of a turbine f provided in an exhaust pipe e through which exhaust gas flows, and receives a rotational output of the turbine f to compress air.

On the other hand, the fuel supply system is equipped with a fuel reformer g, a waste heat boiler h, a desulfurizer i, and a tank j. In this fuel supply system, hydrocarbon fuel (C _m H _n ) and steam (H
₂ O) undergoes an endothermic reaction in the fuel reformer g to change the fuel composition, whereby a fuel having a larger calorific value than the original hydrocarbon fuel can be obtained. The heat energy required for this endothermic reaction is the exhaust pipe e.
It comes from the exhaust gas that flows through.

Specifically, first, since the hydrocarbon fuel contains a sulfur content, the sulfur content is removed by the desulfurization unit i, and the hydrocarbon fuel after the removal of the sulfur content is a fuel reforming. It is supplied to the quality device g. The catalyst of the fuel reformer g (metal (Rh, Ru, Ni, Ir, Pd, Pt, Re,
Co, Fe), alkali carbonates (K ₂ CO ₃ ), basic oxides (MgO, CaO, K ₂ O), coal and other mineral substances (F
eS ₂ ), etc.) may be poisoned by sulfur (hydrogen sulfide in digestion gas or biogas, odorant of city gas, sulfur content of petroleum-based fuel, etc.). A device i and a hydrogen cylinder k for supplying hydrogen to the hydrodesulfurization device i are required. On the other hand, in the exhaust heat boiler h, steam is generated by utilizing the heat quantity of the exhaust gas flowing through the exhaust pipe e, and this steam is supplied to the fuel reformer g. Further, the fuel reformer g is provided with a heat exchanger (not shown) for acquiring the heat energy of the exhaust gas. As a result, the following endothermic reaction takes place inside the fuel reformer g.

C _m H _n + mH ₂ O → mCO + (n / 2 + m) H ₂ (1) When the hydrocarbon fuel is methane (m = 1, n = 4), the following endothermic reaction occurs.

CH ₄ + H ₂ O → CO + 3H ₂ (2) When such a reaction is performed, the calorific value of the fuel after reforming is significantly higher than that of the original hydrocarbon fuel (for example, 25
%), Whereby a fuel capable of improving power generation efficiency (power generator output / supply fuel C _m H _n ) can be obtained.

The reformed fuel is once stored in the tank j, and after removing excess residual H ₂ O by a dehumidifier (not shown) built in the tank j, it is supplied from the air supply system. The mixed air is supplied to the combustion chamber.

[0011]

By the way, the inventor of the present invention, as a method for improving the methane conversion rate in the above-mentioned gas engine, generated when reforming a hydrocarbon fuel with a fuel reformer. It has already been proposed to accelerate the reforming reaction in the fuel reformer by sequentially extracting and extracting hydrogen from the fuel reformer (Japanese Patent Application No. 2000-35).
9956). This makes it possible to promote the endothermic reaction inside the fuel reformer g even if the temperature of the exhaust gas flowing through the exhaust pipe e is relatively low.

However, when the endothermic reaction is promoted by such a method, the hydrogen component ratio in the fuel supplied to the fuel chamber of the gas engine may become too large as compared with other components. In such a situation, the methane number of the supplied fuel becomes too small, and the combustion speed in the combustion chamber becomes too high, resulting in knocking, backfire (flashback), or heat release rate. There is a possibility that it becomes excessive and conversely decreases the thermal efficiency.

As a means for avoiding such a problem that the methane number becomes too small, a sensor such as a knocking sensor is attached to the engine, and based on the detection signal, the amount of separated and extracted hydrogen and the combustion chamber Controlling the amount of hydrogen supply is mentioned.

However, this leads to a complicated structure of the control system of the gas engine and an increase in manufacturing cost, which is not practical.

The present invention has been made in view of the above points, and an object thereof is to separate and extract hydrogen from a fuel reformer when reforming a hydrocarbon fuel in the fuel reformer. On the other hand, another object of the present invention is to provide a configuration capable of avoiding occurrence of knocking and backfire and maintaining high thermal efficiency.

[0016]

[Means for Solving the Problems] -Outline of the Invention-To achieve the above object, the present invention provides a post-reforming fuel obtained by reforming a hydrocarbon fuel in a fuel reformer. A hybrid system that uses hydrogen as fuel for engines other than the gas engine, thereby properly maintaining the methane value of the fuel supplied to the gas engine, and effectively utilizing the hydrogen after separation and extraction. It is provided.

-Solution Means-Specifically, a fuel reformer for reforming a hydrocarbon fuel to produce hydrogen and other fuels, and a hydrogen and other fuels produced by this fuel reformer Hydrogen separating means for separating and extracting hydrogen from inside, a gas engine main body to which the residual fuel after hydrogen is separated and extracted by this hydrogen separating means is supplied, and hydrogen separated and extracted by the hydrogen separating means are supplied as fuel. And a fuel cell for the hybrid system.

Further, a hybrid system having a gas turbine in place of the fuel cell may be used. Furthermore, a hybrid system including both the fuel cell and the gas turbine can be used.

According to these specific matters, the hydrogen separated and extracted by the hydrogen separating means is hardly supplied to the gas engine, and thus the fuel supplied to the gas engine has a high methane number and a combustion speed. Is kept low and there is no knocking or backfire. Also, since the heat generation rate will not become excessive,
The thermal efficiency will also be kept high. Further, the hydrogen after separation and extraction is effectively used as fuel for fuel cells and gas turbines. Generally, the thermal efficiency of fuel cells and gas turbines is the same as or higher than that of gas engines. Therefore, by constructing a hybrid system by combining a gas engine with a fuel cell or a gas turbine, it becomes possible to obtain high thermal efficiency as the entire system.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. In this embodiment, methane gas (C
A case where the present invention is applied as a system equipped with a gas engine in which H ₄ ) is reformed by a fuel reformer to obtain a fuel having a large calorific value will be described. Also,
The gas engine according to this embodiment uses its output for power generation.

(First Embodiment) First, the first embodiment will be described.

-Description of System Configuration- FIG. 1 is a diagram showing a schematic configuration of a system according to the present embodiment. As shown in this figure, in the gas engine 1 provided in this system, an output shaft 21 extending from the engine body 2 is connected to a generator 3, and the rotational driving force of the output shaft 21 causes the generator 3 to generate electricity. It is configured to do.

Further, the intake system of the gas engine 1 comprises an air supply system 4 and a fuel supply system 5, and the air supply system 4
A mixture of air supplied from the engine and fuel supplied from the fuel supply system 5 is supplied to a combustion chamber (not shown) of the engine body 2 to drive the engine body 2. Hereinafter, the air supply system 4 and the fuel supply system 5 will be described.

The air supply system 4 is a supercharger (compressor).
41 and an intercooler 42. That is, after the air is compressed by the supercharger 41, the air is cooled by the intercooler 42 so that high-density air can be supplied toward the combustion chamber. The supercharger 41 is directly connected to an output shaft 62 of a turbine 61 provided in the exhaust pipe 6 through which exhaust gas flows, and
It receives the rotation output of 1 and compresses air.

On the other hand, the fuel supply system 5 includes a fuel reformer 51,
The exhaust heat boiler 52, the high-order desulfurization device 53, the tank 55, etc. are provided. In this fuel supply system 5, the fuel composition is changed by causing an endothermic reaction between methane gas (CH ₄ ) which is a hydrocarbon fuel and steam (H ₂ O) in the fuel reformer 51, whereby the original composition is changed. We are trying to obtain fuel with a larger calorific value than methane gas. The heat energy required for this endothermic reaction is obtained from the exhaust gas flowing through the exhaust pipe 6. Hereinafter, each element constituting the fuel supply system 5 will be described.

Water is supplied from the outside to the exhaust heat boiler 52, and the water is stored inside.
By exchanging heat with the exhaust gas flowing through the water, water is evaporated and steam is generated. The exhaust heat boiler 52 and the fuel reformer 51 are connected by a steam supply pipe 71, and the steam generated in the exhaust heat boiler 52 can be supplied into the fuel reformer 51. Further, the steam supply pipe 71 is provided with an electric valve 71a whose opening can be adjusted.

The high-order desulfurization device 53 is for removing the sulfur content contained in the methane gas. That is,
Catalyst of the fuel reformer 51 (metal (Rh, Ru, Ni, I
r, Pd, Pt, Re, Co, Fe), alkali carbonate (K ₂ CO ₃ ), basic oxide (MgO, CaO, K)
₂ O), minerals such as coal (FeS ₂ ) and the like may be poisoned by sulfur, and in order to avoid this, the high-order desulfurization device 53 is installed. In addition, this high-order desulfurization device 5
3, a pre-reforming fuel supply pipe 72 for supplying methane gas and a desulfurized fuel supply pipe 73 for supplying desulfurized fuel to the fuel reformer 51 are connected.

The high-order desulfurization unit 53 is capable of reducing the sulfur content (generally called slip sulfur) contained in the hydrocarbon fuel to the level of 1 ppb.
High-performance desulfurization operation can be performed even in an environment at room temperature. The principle of the desulfurization is such that the active metal on the metal oxide can also decompose organic sulfur such as thiophene to perform desulfurization.

The desulfurized fuel supply pipe 7 for supplying the fuel from the high-order desulfurization device 53 to the fuel reformer 51.
3 is provided with an electric valve 73a, and during normal operation, both the electric valve 71a of the steam supply pipe 71 and the electric valve 73a of the desulfurized fuel supply pipe 73 are opened to allow the fuel reformer 5 to operate.
1, the methane gas and the steam are supplied to operate the gas engine 1 accompanying the endothermic reaction. On the other hand, when the catalyst of the fuel reformer 51 is poisoned or when the power generation load is small, the electric valve 71a of the steam supply pipe 71 is kept open and the electric valve 73a of the desulfurized fuel supply pipe 73 is closed. It As a result, only steam is supplied to the fuel reformer 51. By supplying only the steam, the sulfur content that causes the poisoning of the catalyst of the fuel reformer 51 is decomposed, whereby the catalyst can be regenerated.

A hydrodesulfurization device may be provided upstream of the high-order desulfurization device 53. According to this, the amount of sulfur introduced into the high-order desulfurization device 53 can be extremely reduced, the efficiency of sulfur removal operation in the high-order desulfurization device 53 can be improved, and the life of the high-order desulfurization device 53 can be extended. Can be achieved.

The fuel reformer 51 has an endothermic reaction between steam and methane gas to perform a fuel reforming operation. That is, an endothermic reaction is performed between the steam supplied from the steam supply pipe 71 and the methane gas supplied from the desulfurized fuel supply pipe 73. Further, inside the fuel reformer 51, a heat exchanger (not shown) for obtaining the heat energy of the exhaust gas is provided. As a result, the following endothermic reaction is performed inside the fuel reformer 51 under an environment of a predetermined temperature (exhaust gas temperature of about 600 ° C., for example).

CH ₄ + H ₂ O → CO + 3H ₂ (2) By carrying out such a reaction, the calorific value of the fuel after reforming is significantly higher than that of the original methane gas, which causes power generation efficiency (power generation). It is possible to obtain fuel that can improve the machine output / fuel supply).

Further, the fuel reformer 51 and the tank 55 are provided with the fuel etc. (H ₂ , C obtained by the endothermic reaction).
O, CH ₄ , H ₂ O) are connected to each other by a fuel supply pipe 76 for supplying them toward the tank 55. The fuel supply pipe 76 is provided with an electric valve 76a whose opening can be adjusted.

The tank 55 to which the fuel is supplied by the fuel supply pipe 76 temporarily stores the fuel, mixes the reformed fuel with the air through the reformed fuel supply pipe 78, and supplies the mixed fuel to the combustion chamber. It is supposed to do.

The fuel reformer 51 is provided with a hydrogen separator 56 as a hydrogen separator. The hydrogen separator 56 separates and extracts hydrogen gas generated by the endothermic reaction in the fuel reformer 51 from other gases and steam. As a specific configuration of the hydrogen separation device 56, a separation membrane is arranged in the internal space thereof, and the separation membrane separates the upstream side primary side space and the downstream side secondary side space. The primary side space is the fuel reformer 51.
In the space on the side, hydrogen gas and other gases generated by the endothermic reaction are present. A hydrogen recovery pipe 75, which will be described later, is connected to the secondary space, and the hydrogen gas separated and extracted by the separation membrane is led to the hydrogen recovery pipe 75.

Examples of the separation membrane include palladium alloy, palladium-based alloy, inorganic separation membrane, porous glass membrane, porous hollow glass fiber membrane, porous ceramic membrane, zeolite membrane, cellulose acetate membrane, polyimide, polyamide, polysulfone porous. Membrane / silicone. For example, the inorganic separation membrane is formed as a membrane having pores through which only hydrogen molecules can pass. In particular, inorganic separation membranes, porous glass membranes, porous hollow glass fiber membranes, and porous ceramics membranes are preferable because they have excellent heat resistance and high mechanical strength. Further, as the porous ceramic material, specifically,
Examples include zirconia, zeolite, silica and alumina.

In addition to the above structure, the hydrogen separator 56
A hydrogen storage substance may be housed in the secondary side space of the above to accelerate the separation and extraction of hydrogen gas. Examples of this hydrogen storage material include hydrogen storage alloys. In addition, carbon nanofibers, fullerenes, multi-layer fullerenes, substances composed of carbon molecules such as carbon nanotubes, metal hydrides, salt hydrides, metal bond hydrides, boundary region hydrides, covalent bond hydrides, organic carbonization It is also possible to adopt hydrogen, metal hydride, or chemical hydride as the hydrogen storage substance.

The separation membrane and the hydrogen storage material are not limited to these, and various materials can be used as long as they can separate and extract hydrogen. With this configuration, the hydrogen generated by the endothermic reaction in the fuel reformer 51 is sequentially separated and extracted by the hydrogen separator 56, so that the endothermic reaction in the fuel reformer 51 can be promoted. .

The secondary space of the hydrogen separator 56 is connected to the hydrogen pump unit 9. The hydrogen pump unit 9 will be described below.

One of the hydrogen pump units 9 is connected to the secondary space of the hydrogen separator 56 by a hydrogen recovery pipe 75. In addition, as a feature of this embodiment, the other side of the hydrogen pump unit 9 is connected to the fuel cell 100, which is one element of the present hybrid system, by the hydrogen discharge pipe 91. That is, the hydrogen separated and extracted by the hydrogen separator 56 is supplied to the fuel cell 100 via the hydrogen pump unit 9, and the fuel cell 100 is supplied with the hydrogen.
The fuel is used as fuel. Further, the hydrogen release pipe 91 is provided with an electric valve 91a whose opening can be adjusted.

As the fuel cell 100, an alkaline type (see, for example, JP 2001-106503 A), a phosphoric acid type (see, for example, JP 2001-196082 A),
Molten carbonate type (see, for example, JP 2001-229940 A), solid electrolyte type (for example, JP 2001-19608 A).
4), solid polymer type (for example, JP 2001-20
No. 2982) is adopted.

The hydrogen pump unit 9 includes first and second hydrogen pumps 92 and (93) which are formed by connecting a pair of hydrogen storage bodies 92a and 92b and (93a and 93b) in series.
A hydrogen storage body 94 connected to the hydrogen pumps 92 and (93) is provided. These hydrogen storage bodies 92a to 93b
The hydrogen storage body 94 and the hydrogen storage body 94 each contain the above-mentioned hydrogen storage material. In addition, these hydrogen storage bodies 92a to 93
b and the hydrogen storage body 94 are provided with a hot / cold heat source (not shown). When cooled by this hot / cold heat source, hydrogen storage operation is performed, and when heated, hydrogen release operation is performed. Has become. It is also possible to use the exhaust heat of the engine body 2 as this heating source. In addition to the hydrogen storage alloy tank, specifically, a compressed hydrogen tank, a liquid hydrogen tank, a metal hydride tank, a chemical hydride tank, or the like can be adopted as the configuration of the hydrogen storage body 94.

In the hydrogen pump unit 9 thus constructed, in the individual hydrogen pumps 92 and 93, the upstream hydrogen storage bodies 92a and (93a) are cooled and the downstream hydrogen storage bodies 92b and (93b) are cooled. When heated, hydrogen is taken out from the secondary space of the hydrogen separator 56 and stored in the upstream hydrogen storage bodies 92a, (93a), and at the same time, the downstream hydrogen storage bodies 92b, (93b) are stored. In (), the hydrogen that has been stored in advance is released toward the fuel cell 100 (hereinafter, hydrogen absorption / release operation). On the contrary, when the upstream side hydrogen storage bodies 92a, (93a) are heated and the downstream side hydrogen storage bodies 92b, (93b) are cooled, the upstream side hydrogen storage bodies 92a, (93a) store the hydrogen storage bodies 92a, (93a). The stored hydrogen is supplied to the hydrogen storage bodies 92b, (93b) on the downstream side and stored in the hydrogen storage bodies 92b, (93b) on the downstream side (hereinafter, hydrogen storage preliminary operation). Then, in each of the hydrogen pumps 92 and 93, a state in which one performs a hydrogen absorption / desorption operation and the other performs a hydrogen storage preliminary operation is alternately repeated at predetermined time intervals. As a result, the hydrogen separator 5
The hydrogen taken out from the secondary side space 6 can be continuously discharged toward the fuel cell 100.

Further, when the load on the fuel cell 100 is cut off (when fuel supply to the fuel cell 100 is not necessary), the hydrogen storage body 94 is cooled and hydrogen in the secondary space of the hydrogen separation device 56 is taken out. To temporarily store. When the load is applied, the hydrogen storage body 94 is heated, and the stored hydrogen is released to the fuel cell 100. As a result, an appropriate amount of hydrogen gas according to the operating state of the fuel cell 100 can be supplied as fuel, and good responsiveness of the fuel cell 100 can be obtained.

The operation of adjusting the amount of hydrogen gas released to the fuel cell 100 is performed by the above-mentioned hydrogen storage bodies 92a to 93.
b, the heating and cooling of the hydrogen storage body 94 are controlled, and the opening degree of the electric valve 91a is controlled. Further, a check valve or the like may be provided at each position so that the reverse flow of hydrogen gas in the hydrogen pump unit 9 is blocked so that the above-described operations can be favorably performed.

With the above structure, the hydrogen pump unit 9 can simultaneously and continuously take out hydrogen from the secondary space of the hydrogen separator 56 and release hydrogen toward the fuel cell 100. Further, as a driving principle of the hydrogen pump unit 9, a configuration is adopted in which storage and release of hydrogen are switched depending on temperature, so that exhaust heat of the engine or the like can be effectively used to release hydrogen. It is also possible to eliminate the special power source for.

Further, the fuel supply system 5 of the present gas engine 1 has a heat exchanger 57 and a deionized water device 58 in addition to the above structure.
Is provided.

The heat exchanger 57 includes the reformed fuel (reformed gas) flowing through the fuel supply pipe 76 and the methane gas supplied to the fuel reformer 51 (the methane gas after being desulfurized by the high-order desulfurization device 53). ) Is to exchange heat with.
As a result, the methane gas supplied to the fuel reformer 51 can be preheated. In addition, this heat exchanger 57
Is the reformed fuel (reformed gas) flowing through the fuel supply pipe 76.
And heat exchange is performed between the pure water supplied from the pure water device 58 to the exhaust heat boiler 52. Thereby, the pure water supplied to the exhaust heat boiler 52 can be preheated. As described above, by adopting the configuration in which the methane gas and the pure water which are the raw materials of the gas engine 1 are preheated by the reformed fuel, the thermal energy in the reformed fuel can be recovered and the exhaust heat recovery amount can be increased. Can be achieved.

The pure water device 58 is a water supply pipe 58a.
Is connected to the exhaust heat boiler 52 by the heat exchanger 5
7 is connected to this water supply pipe 58a by a water return pipe 57a. That is, the water formed by condensing the water contained in the reformed fuel by the heat exchanger 57 is used as the waste heat boiler 52.
It can be used as a raw material for the steam generated in. Therefore, the water contained in the reformed fuel can be effectively used without being discarded, and the maintenance cost of the pure water supply facility can be reduced.

On the other hand, the pure water device 58 is supplied with, for example, tap water, generates pure water from the tap water, and supplies the pure water to the exhaust heat boiler 52 through the water supply pipe 58a. That is, high purity pure water is generated by removing impurities such as halogen and arsenic contained in tap water. Specific examples of the pure water device 58 include a distillation pure water device, a cartridge pure water device, an ion exchange pure water device, an electric regeneration pure water device, and a continuous ion exchange method applying the electrodialysis principle ( Devices such as EDI) are listed.

In particular, as a method for removing halogen, activated carbon filtration method, microfiltration method (by MF membrane (microfilter) or the like), ultrafiltration method (by UF membrane (ultrafilter) or the like), reverse osmosis At least one of the membrane methods (by RO membrane (reverse osmosis) etc.) is selected. On the other hand, as a method for removing arsenic, coagulation sedimentation method (precipitation method), ion exchange method, activated alumina method, low pressure reverse osmosis membrane method, reverse osmosis membrane method (pressure is applied in the direction opposite to the osmotic pressure) Method) and at least one of the ADI methods is selected.

For example, in the above sedimentation method, raw water (tap water)
An oxidant and a coagulant are injected into the mixture, which are mixed by a mixer and passed through a UD filter. At this time, when raw water passes through the filter layer of the filter, agglomerated flocs incorporating arsenic are supplemented. This treated water is filtered more rapidly to remove residual arsenic and suspended matter.

In the activated alumina method, the oxidizing agent and the raw water into which the acid for adjusting the pH has been injected are mixed in a mixer, and the mixture is fed into an activated alumina adsorption tower. Then, this treated water is readjusted in the purification pond to raise the pH value to near neutral. Furthermore, suspended matter, iron, manganese, etc. are removed by a filter.

Here, pure water generally means water containing impurities at a concentration of the order of ppm (mg / l). Moreover, the high-performance pure water device 58 can also generate ultrapure water. The ultrapure water generally means water containing impurities at a concentration on the order of ppb (μg / l).

By thus converting the water supplied to the exhaust heat boiler 52 to pure water, it is possible to prevent the steam supplied to the fuel reformer 51 from containing impurities such as halogen and arsenic. In this way, the endothermic reaction can be efficiently performed. As a result, the life of the fuel reformer 51 and the exhaust heat boiler 52 can be extended, and the cost can be reduced by eliminating the need for a pure water tank.

-Description of Operation of Gas Engine 1- Next, the operation of the gas engine 1 configured as described above will be described.

First, with the motor-operated valve 71a of the steam supply pipe 71 being opened, the water supplied from the deionizer 58 to the exhaust heat boiler 52 is exhausted by the exhaust pipe 6 in the exhaust heat boiler 52.
It is heated by the exhaust gas flowing through and becomes steam. Then, this steam is sequentially supplied to the fuel reformer 51 through the steam supply pipe 71.

At the same time, methane gas is supplied to the high-order desulfurization device 53 by the pre-reforming fuel supply pipe 72, and the desulfurization operation is performed here. In the desulfurization operation in the high-order desulfurization device 53, as described above, slip sulfur can be reduced to the level of 1 ppb in a room temperature environment. Therefore, almost no sulfur is present in the methane gas supplied from the higher-order desulfurization device 53 to the fuel reformer 51 by the desulfurization fuel supply pipe 73, and the catalyst of the fuel reformer 51 is almost not poisoned. Disappear.

In this way, the above endothermic reaction is carried out with the steam and methane gas supplied to the fuel reformer 51. In addition to steam and methane gas, the fuel reformer 51 also includes air, oxygen (O ₂ ), carbon dioxide (C
O ₂ ) is also supplied. During the endothermic reaction,
The heat energy of the exhaust gas is acquired by the heat exchanger in the fuel reformer 51, whereby an endothermic reaction is performed inside the fuel reformer 51 under an environment of a predetermined temperature, and carbon monoxide (CO) is generated. And hydrogen gas (H ₂ ) are generated. At this time, unreformed steam (H ₂ O) and methane gas (CH ₄ ) are also present inside the fuel reformer 51.

The hydrogen gas in the fuel reformer 51 is separated and extracted from other gases and water vapor by the hydrogen separator 56, and is taken out by the hydrogen recovery pipe 75. By separating and extracting the hydrogen gas in the fuel reformer 51, an endothermic reaction is promoted in the fuel reformer 51,
The fuel is reformed at a high conversion rate.

When fuel is supplied to the engine body 2,
The electric valve 76a of the fuel supply pipe 76 is opened.
The residual hydrogen gas, methane gas, carbon monoxide, and water vapor in the fuel reformer 51 are supplied to the tank 55 by the fuel supply pipe 76. Then, the reformed fuel is mixed with the air supplied from the air supply system 4 from the tank 55 through the reformed fuel supply pipe 78 and is supplied to the combustion chamber of the engine body 2. As a result, the engine body 2 is driven and the output shaft 21
The generator 3 is driven in accordance with the rotational driving of No. 3, and electric power is generated.

On the other hand, the hydrogen gas separated and extracted from the fuel reformer 51 by the hydrogen separator 56 is the hydrogen recovery pipe 75.
It is introduced into the hydrogen pump unit 9 via In the hydrogen pump unit 9, a state in which one of the hydrogen pumps 92 and 93 performs a hydrogen storage / release operation and the other performs a hydrogen storage preliminary operation is alternately repeated at predetermined time intervals. This allows
Hydrogen taken out from the secondary space of the hydrogen separation device 56 is continuously discharged toward the fuel cell 100, and the fuel cell 100 performs a power generation operation using the hydrogen and oxygen in the atmosphere as fuel.

-Effects of the Embodiment-As described above, in the present embodiment, the hydrogen separated and extracted by the hydrogen separator 56 is hardly supplied to the gas engine 1, but is supplied to the gas engine 1. The fuel has a high methane number and a low burning rate, so that knocking and backfire can be avoided. Further, since the heat generation rate does not become excessively high, the thermal efficiency can be maintained high.

The hydrogen after separation and extraction is the fuel cell 100.
It is effectively used as fuel. Generally, the efficiency of the fuel cell 100 is higher than that of the gas engine 1. Therefore, by constructing the hybrid system by combining the gas engine 1 and the fuel cell 100, it becomes possible to obtain high efficiency as the entire system.

Furthermore, since the fuel cell 100 does not generate harmful substances such as NOx, it is possible to provide a suitable hybrid system having a very small effect on the environment.

(Second Embodiment) Next, a second embodiment will be described. The present embodiment is a modification of the usage pattern of hydrogen separated and extracted by the hydrogen separator 56. Other configurations are similar to those of the above-described first embodiment. Therefore, only the differences from the first embodiment will be described here.

As shown in FIG. 2, in the hybrid system according to this embodiment, a gas turbine (micro gas turbine) is used instead of the fuel cell 100 in the first embodiment.
Equipped with 200. That is, the separated and extracted hydrogen can be used as fuel for the gas turbine 200.

As a concrete configuration of this micro gas turbine, for example, the one disclosed in Japanese Patent Laid-Open No. 2001-193478 can be cited.

Further, the output shaft 2 of this gas turbine 200
A high speed generator 202 is connected to 01, and the rotational driving force of the output shaft 201 causes the high speed generator 202 to generate electric power.

Also in this embodiment, the hydrogen separated and extracted by the hydrogen separator 56 is hardly supplied to the gas engine 1, and the methane number of the fuel supplied to the gas engine 1 is high and the combustion speed is high. Can be kept low to avoid knocking and backfire. Further, since the heat generation rate does not become excessive, the heat efficiency is maintained high.

The hydrogen after separation and extraction is the gas turbine 2
00 is effectively used as fuel. Gas turbine 200
The efficiency can be substantially equal to or higher than that of the gas engine 1 by adopting a gas turbine having a high turbine inlet temperature. Therefore, by constructing the hybrid system by combining the gas engine 1 and the gas turbine 200, it is possible to obtain high efficiency as the entire system.

-Other Embodiments- In the above-described embodiment, the present invention is applied to the gas engine 1 in which methane gas as a hydrocarbon fuel is reformed by the fuel reformer 51 to obtain a fuel having a large calorific value. I explained about the case. The present invention is not limited to this, and as the hydrocarbon fuel, it is also possible to apply fuels such as natural gas, petroleum liquid fuel, digestive gas, biogas, alcohol fuel and the like.

The gas engine is not limited to the one for power generation, but the present invention can be applied to gas engines used for various purposes.

Further, in order to further promote the endothermic reaction in the fuel reformer 51, separated hydrogen, reformed fuel (fuel after reforming and other than hydrogen) is formed inside the fuel reformer 51. ) Or a part of hydrocarbon fuel (fuel before reforming) is burned to raise the internal temperature of the fuel reformer 51. With this configuration,
In combination with the effect of promoting the endothermic reaction by extracting hydrogen from the fuel reformer 51, an extremely high conversion rate can be realized.

Further, in each of the above-mentioned embodiments, the fuel reforming is carried out by causing the endothermic reaction between the steam and the hydrocarbon fuel, but the present invention causes the endothermic reaction between carbon dioxide and the hydrocarbon fuel. It is also possible to apply it to fuel reforming.

In addition, in the first embodiment, the gas engine 1 and the fuel cell 100 form a hybrid system, and in the second embodiment, the gas engine 1 and the gas turbine 200 form a hybrid system. A hybrid system may be configured by the gas engine 1, the fuel cell 100, and the gas turbine 200, and the hydrogen separated and extracted by the hydrogen separation device 56 may be supplied to the fuel cell 100 and the gas turbine 200, respectively.

[0077]

As described above, according to the present invention, a gas engine to which the residual fuel after hydrogen is separated and extracted is supplied,
The fuel cell and the gas turbine are provided with the hydrogen separated and extracted from the reformed fuel by the hydrogen separation means. Therefore, the methane value of the fuel supplied to the gas engine is high and the combustion speed is kept low, and knocking or backfire does not occur. Further, since the heat generation rate does not become excessively high, the thermal efficiency can be maintained high. In addition, no special configuration or control system is required to avoid excessive knocking, backfire, or heat generation rate, which enables stable gas engine operation while simplifying the configuration and reducing manufacturing costs. It can be carried out.

Further, since hydrogen after separation and extraction is effectively used as fuel for fuel cells and gas turbines, it is possible to obtain high efficiency as a whole system. Furthermore, since the amount of harmful substances such as NOx generated in fuel cells and gas turbines is extremely small compared to that in gas engines (the amount of harmful substances generated in fuel cells is extremely small), there is very little impact on the environment. It becomes possible to provide a hybrid system.

[Brief description of drawings]

FIG. 1 is a diagram showing a schematic configuration of a hybrid system according to a first embodiment.

FIG. 2 is a diagram showing a schematic configuration of a hybrid system according to a second embodiment.

FIG. 3 is a diagram showing a schematic configuration of a conventional power generation system that generates power by a gas engine.

[Explanation of symbols]

1 gas engine 51 Fuel reformer 56 Hydrogen separation device (hydrogen separation means) 100 fuel cell 200 gas turbine

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) F02C 3/22 F02C 3/22 F02D 19/02 F02D 19/02 C F02M 27/02 F02M 27/02 A H01M 8/00 H01M 8/00 Z 8/06 8/06 GF Term (reference) 3G081 BA11 DA22 3G092 AB06 AB15 AC02 AC08 DE17S FA01 4G040 EA03 EA06 EB01 EB03 EB33 EB42 EB43 FA02 FB01 FC01 FE01 5H027 AA02 BA01 BA16 DD00

Claims (3)

[Claims] 1. A fuel reformer for reforming a hydrocarbon-based fuel to produce hydrogen and other fuels, and hydrogen separated and extracted from the hydrogen and other fuels produced by the fuel reformer. A hydrogen separating means, a gas engine main body to which the residual fuel after hydrogen is separated and extracted by the hydrogen separating means is supplied, and a fuel cell to which the hydrogen separated and extracted by the hydrogen separating means is supplied as a fuel. A hybrid system equipped with a gas engine. 2. A fuel reformer for reforming a hydrocarbon-based fuel to produce hydrogen and other fuels, and hydrogen separated and extracted from the hydrogen and other fuels produced by the fuel reformer. A hydrogen separating means, a gas engine main body to which the residual fuel after hydrogen is separated and extracted by the hydrogen separating means is supplied, and a gas turbine to which the hydrogen separated and extracted by the hydrogen separating means is supplied as a fuel A hybrid system equipped with a gas engine. 3. A fuel reformer for reforming a hydrocarbon-based fuel to produce hydrogen and other fuels, and hydrogen separated and extracted from the hydrogen and other fuels produced by the fuel reformer. Hydrogen separation means, a gas engine body to which the residual fuel after hydrogen has been separated and extracted by the hydrogen separation means is supplied, and a fuel cell and a gas turbine to which the hydrogen separated and extracted by the hydrogen separation means is supplied as fuel A hybrid system equipped with a gas engine, characterized by being equipped with.