JPS60158558A - Fuel cell power generating system - Google Patents

Abstract

PURPOSE:To readily increase cell operating pressure from atmospheric pressure to rated operating pressure in starting by installing a brahch means by which an excess fuel which flows in an excess fuel line through a fuel electrode is introduced into an atmospheric release circuit. CONSTITUTION:When operating pressure slightly exceeds back pressure, a three- way control valve 14 which was completely opened in a flare stack 16 direction is gradually opened in an excess gas outlet direction, and excess gas flow is gradually switched from a flare stack 16 direction to an excess gas circuit. After the three-way control valve 14 was completely opened in the excess gas outlet direction, operating pressure is increased to rated operating pressure by throttling a pressure control valve 11. A check valve 15 prevents back flow when back pressure is high. Thereby, pressure can be increased with excess fuel sets free to the flare stack 16 in cell starting. Switching from the flare stack circuit to the excess fuel circuit is easily performed. Operating pressure of a cell is easily kept and controlled without giving quick pressure change to a fuel cell main body 1.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a fuel cell centered system that utilizes hydrogen-based gas as a fuel.

[Prior art]

In petrochemical plants such as salt electrolysis plants and ethylene plants, a large amount of hydrogen is generated as a byproduct during the product production process.

Conventionally, this by-product hydrogen was usually sold in cylinders after refining, or used as a heat source in boilers and other equipment in some industrial complexes. In recent years, with the development of fuel cell power generation systems, one of the new uses of fuel cell power generation systems has been developed.
One possible solution is a system that utilizes this by-product hydrogen, and is being studied in various fields.

Unlike systems that use natural gas as fuel, fuel cell power generation systems that use by-product hydrogen do not require a fuel reformer, resulting in lower plant costs, lower plant configurations, and
We can expect improvements in plan efficiency, etc.

Figure 1 shows a conventional general fuel cell system using by-product hydrogen. In the figure, 111 is the main body of the fuel cell, which includes fuel types αa and non-polar (ib).)2).

(3) is the fuel cell main body + 11 fuel electrode (1a) entrance country 140 raw hydrogen supply line and fuel electrode (la) exit side surplus fuel line, +41, 15] is the fuel cell main body fil
air supply line and air u+ on the lb inlet side
< (lb) Bo size on the exit side? Air line, (6) is a steam water separator, +71 I''i ring water pump 8) is a d pond cooling water line, +91fl steam extraction line, (+o)
, +121 are flow rate regulating valves for controlling the fuel and air flows Mk, respectively, and 1181 is a pressure regulating valve for keeping the operating pressure of the battery constant.

Next, regarding the operation, the by-product hydrogen generated in the chemical plant is passed through the entire by-product hydrogen supply line (2) (
After the amount of Ijfl is simulated by W and 1 with the rough amount of strain (lO), the fuel type (1~) of the wet 4- + electric ton body (1) is used. It is consumed at the fuel electrode (1a). , the surplus fuel after t is
Excess fuel is discharged out of the system via the excess fuel line (3) and pressure regulating valve (1).

This rest! Ill fuel tanks are used for fuel, etc. in treetop sales or within plants. General PCs and fuel F+ batteries require a certain amount of operating pressure (e.g. 4 to AVLA) to improve their characteristics.
) is required, so an elevating If device (not shown) is placed in the supply line (2) when the pressure of the by-product hydrogen is low. However, in general, petrochemical plants do not require a special booster because high-pressure by-product hydrogen is obtained.

On the other hand, the air pressurized by the compressor (not shown) passes through the air supply line (4) and is fully distorted by the light intensity adjustment valve (121).
(The air injected into 1υ and consumed in 1υ is discharged to the outside of the thread via the air line (5) and the pressure regulating valve (131).

Disconnected circulating water pump (7), - pond cooling water line (8),
The cooling system for the battery is made up of 14w+6+ of air and moisture. % moisture The steam discharged from the porcelain (6) is discharged out of the system through the entire discharge line (9).

This steam is used as factory steam for magnetization equipment or for cooling/heating, or is recovered as power for a steam turbine photovoltaic unit.In such a fuel cell system using by-product hydrogen, the fuel electrode Qa ), when the surplus fuel after being consumed is discharged from the system, it generally has a value If (for example, 2 to 3 G) outside the system.

On the other hand, when pumping Kamoura, it is necessary to increase the operating pressure from atmospheric pressure to operating pressure.
It is necessary to increase the pressure of the fuel gas supplied to the battery via the supply line (21) from atmospheric pressure to operating pressure by FF1f.At this time, since the excess fuel line (3) has back pressure outside the system, the configuration as it is will not be changed. As long as the operating pressure of the fuel cell is lower than this d pressure, it is very difficult to control the operating pressure of the fuel cell.

Furthermore, in the fuel cell main body +11, the fuel electrode (la
), gas leak (crossover) between Q tank (ib)
In order to prevent this, the differential pressure 'fI:4JC between the two electrodes must be kept to a small value, and adjustment of the fuel gas pressure in the cell requires precision.

[Summary of the invention]

This invention was made in view of the above-mentioned drawbacks of the conventional ones. When the system is started, the fuel cell's fuel reserve ψ", the surplus fuel flowing through the fuel line, is released into the atmosphere release circuit. By installing a branching means, a fuel cell generation system kW is provided which can supplementally increase the operating pressure of the fuel cell from full atmospheric pressure to the rated operating pressure when the system is started.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described in 1. with reference to FIG. 2. l) to (131 are the same as the conventional amounts described above. - is the fuel 4fi of the fuel cell main body II+
(la) Branching means (hereinafter referred to as a three-way control valve) installed on the surplus fuel line (31) on the outlet side, for example, a three-way control valve (hereinafter referred to as a three-way control valve), which connects one outlet of the three-way control valve +14. The other outlet is connected to the surplus fuel discharge circuit outside the system, and the other outlet is connected to the atmosphere release circuit, so that when the system is started, the surplus fuel P+ flowing through the surplus fuel line (3) is discharged to the atmosphere release circuit. .

uai check valve, +161 is flare stack.

In this advanced system, a means for increasing the total operating pressure of the cell at the time of starting the fuel cell will be explained.

'-When starting the battery, the fuel electrode (1a) and air electrode (1a)
It is necessary to gradually increase the pressure of the fuel gas and nitrogen while controlling the ax pressure of t)) to a minute value. When the cell is stopped, the flow rate regulating valve (10) on the by-product hydrogen supply line (2) on the inlet side of the fuel electrode (la) of the fuel cell main body il+ is in a closed state. At that time, the pressure regulating valve l1l on the fuel electrode (la) outlet side extra fuel inlet L31) e is fully open, and the three-way regulating valve t141 t
Keep the flare stack fully open in the L direction. At this time, the flow control valve (121 is closed) on the air side as well.
In the state where the pressure regulator jl:ll is fully open, the cylinder is at atmospheric pressure. At the time of battery startup, the flow rate adjustment valve t101 f on the by-product hydrogen supply line (2) gradually opens, and at the same time, the pressure adjustment valve (t101f) on the surplus fuel line (3) tightens the pressure. The pressure of the waste flowing to the fuel electrode (la) can be increased by
i? Of course, the same operation should be performed on the nitrogen side to maintain the same. This operation is carried out in a trench where the operating pressure reaches the back pressure of excess fuel. When the operating pressure is equal to the back pressure or slightly exceeds #If'k JM, the three-way regulating valve tl(1), which was fully open toward the flare stack, is gradually opened toward the surplus fuel outlet.

As a result of this feat, the flow of fuel is gradually switched from the flare stack circuit to the outside fuel circuit, which is used for recovery purposes. After the three-way regulating valve t141 is fully opened in the direction of the fuel outlet, the pressure regulating valve (11) is further throttled to raise the operating pressure to the operating pressure 'kf. This is to prevent backflow when the pressure is high.◎ As mentioned above, the three-way regulating valve (14) is connected to the fuel cell main body (14).
) by installing it on the excess fuel line (3) on the outlet side of the fuel electrode (la), it is possible to raise the pressure of C while releasing excess fuel to the entire flare stack when starting the battery, and also to increase the pressure of C from the flare stack circuit. Switching to an external fuel circuit can be easily performed, and there is no sudden pressure fluctuation in the fuel cell main body +l+, making it easy to maintain and control the operating pressure of the battery. Become.

In the above embodiment, a case was described in which the branching means α was a three-way regulating valve, but as the branching means (141), a branch pipe was provided in the surplus fuel line (3), and this branch a and the surplus fuel line (3) By opening and closing the regulating valves, the same operations as those in the above embodiment may be performed, and the same effects can be obtained.

In addition, the above example describes a fuel cell system that makes full use of by-product hydrogen in a chemical plant, but the application field is not limited to chemical plants in particular, and water can be separated if it can be used as a fuel. This fuel cell main body system can be applied with the same effect regardless of whether the bone is whole or not.

〔Effect of the invention〕

As described above, according to the present invention, all the branching means are installed to guide the surplus fuel flowing through the surplus fuel line through the fuel goose of the fuel cell main body to the atmosphere release circuit when the system is started.
It is possible to obtain a fuel cell power generation system that can easily increase the operating pressure of the fuel cell from atmospheric pressure to the rated operating pressure when the fuel cell is waiting for startup.

[Brief explanation of the drawing]

FIG. 1 is a system diagram showing a conventional fuel cell power generation system, and FIG. 2 is a system diagram showing a fuel cell power generation system according to an embodiment of the present invention. In the figure, (1) is the fuel cell main body, (3) is the surplus fuel line, and +14) is the branching means. In the figure, the same reference numerals v1 and - or equivalent parts are shown. Daikonto Masao Masao

Claims (1)

[Scope of Claims] +11 In the Hunryutunchi Shuntun system that uses hydrogen-based gas as a fuel and connects a surplus fuel line to the fuel electrode outlet side of the fuel cell body, when the system is started, the fuel cell body A fuel cell-based system comprising a branching means for diverting the surplus fuel flowing through the surplus fuel line to the atmosphere release circuit. (21) The fuel cell main body system according to claim 11, characterized in that the branching means is constituted by a Sanmancho firefly valve. (3) The branching means is a branch pipe branched to a surplus fuel line, The fuel cell power generation system described in Section 4, Paragraph 1 of Patent No. 68, which is characterized by being constituted by the branch line and the redundant valve provided in each of the surplus fuel lines.