CN111193050B

CN111193050B - Reforming high-temperature fuel cell system and starting method thereof

Info

Publication number: CN111193050B
Application number: CN201811350216.5A
Authority: CN
Inventors: 杨林林; 高越; 孙公权
Original assignee: Dalian Institute of Chemical Physics of CAS
Current assignee: Dalian Institute of Chemical Physics of CAS
Priority date: 2018-11-14
Filing date: 2018-11-14
Publication date: 2021-03-12
Anticipated expiration: 2038-11-14
Also published as: CN111193050A

Abstract

The invention provides a high-temperature fuel cell system for reforming fuel by quick start in a segmented mode and a start-up method thereof, wherein the system comprises a reformer I, a reformer II, a heat exchanger and a galvanic pile; reformer I includes a burner I and reformer II includes a burner II. Heating a fuel reformer in stages, wherein the fuel reformer comprises a reformer I and a reformer II; and the step of heating in stages is to heat the reformer I and then heat the reformer II by using the heat of the tail gas of the galvanic pile. By adopting the sectional heating, the heat of the electric pile is supplied to the fuel reformer which is not heated for heating, so that the utilization efficiency of the system energy is greatly improved, and the quick start of the system is realized.

Description

Reforming high-temperature fuel cell system and starting method thereof

Technical Field

The invention belongs to the field of high-temperature fuel cell systems, and particularly relates to a segmented quick-start fuel reforming high-temperature fuel cell system and a starting method thereof.

Background

For high temperature fuel cell systems, an excessively long start-up time has been a key issue to be solved, wherein the main time of the warm-up phase is to heat the fuel reformer and the stack to the operating temperature simultaneously. The current start-up sequence of high temperature fuel cell systems is to simultaneously heat the stack and the fuel reformer in the system to operating temperatures by electrical heating and catalytic combustion, respectively. Since the stack needs to be discharged with a small current before reaching the operating temperature point, the fuel reformer needs to be heated to the actual operating temperature first. However, excessive H is not required for small current discharge₂The feed, i.e. the fuel reformer, does not require full power to produce H₂. Heating the overall fuel reformer to operating temperature would inevitably result in a waste of fuel and electricity.

Disclosure of Invention

Considering that the conventional temperature raising strategy has a long time for normal discharge after all components reach the rated working temperature, the fuel reformer is selected to be split into a plurality of parts which are respectively heated,in addition, the electric pile is not discharged at rated power in the starting stage, and because the electric pile generates heat when discharging from low power to rated power, the invention considers that the fuel reformer with larger heat capacity is heated in sections, thereby ensuring that the supply meets the H required by the electric pile in the starting stage₂Namely, the surplus H of the anode tail gas of the galvanic pile is recycled₂And a stack thermal cycle medium (air or heat transfer oil, etc.) provides heat for the remaining fuel reformers. Because the difference between the working temperature of the galvanic pile and the working temperature of the fuel reformer is about 100 ℃, part of heat is larger but the temperature is lower, and the heat cannot be absorbed by the reforming reaction originally, the heat generated by the galvanic pile can not be directly supplied to the fuel reformer in the system working process; under the starting strategy, the heat of the electric pile is provided for the fuel reformer which is not heated for heating, so that the utilization efficiency of the system energy is greatly improved, and the quick starting of the system is realized.

The invention relates to a starting method for a high-temperature fuel cell system by quickly starting a fuel reformer in a sectional manner. In a high-temperature fuel cell system, since the stack cannot be discharged at a rated power when the temperature is lower than the rated temperature, it is considered to shorten the start-up time of the cell system by not heating up all the fuel reformers. And in the process of waiting for the temperature of the galvanic pile to rise to the rated temperature, catalytic combustion is carried out by using a galvanic pile heat-radiating medium and the galvanic pile anode tail gas to heat the other part of the fuel reformer.

The following technical scheme is adopted specifically:

one aspect of the present invention provides a starting method for a reforming high-temperature fuel cell system, the starting method comprising: heating a fuel reformer in stages, wherein the fuel reformer comprises a reformer I and a reformer II; and the step of heating in stages is to heat the reformer I and then heat the reformer II by using the heat of the tail gas of the galvanic pile.

Based on the technical scheme, preferably, the electric pile and the reformer I are started, and a combustor (1) and electric heating are used for providing heat for the system; when the reformer I reaches the working temperature and the galvanic pile reaches the low-power operation temperature, the fuel pump of the reformer I is started to enable the system to work at low power, and the galvanic pile is used at the momentProviding heat-dissipating circulating medium to exchange heat with the reformer II; and meanwhile, the anode tail gas of the galvanic pile is subjected to catalytic combustion in the combustor II, heat is provided for the reformer II, when the temperature of the reformer II is consistent with that of the galvanic pile, a galvanic pile heat-dissipation medium channel entering the reformer II is closed, and only the anode tail gas of the galvanic pile is subjected to catalytic combustion and continuously provided with a heat source for the reformer II. When the temperature of the electric pile and the temperature of the reformer II reach the respective rated working temperatures, opening the valve I and opening the fuel pump of the reformer II to provide H for the electric pile₂Source, and system rated power output.

In another aspect, the present invention provides a reforming high temperature fuel cell system, the system comprising a reformer I, a reformer II, a heat exchanger, and a stack; reformer I includes a burner I and reformer II includes a burner II.

Based on the technical scheme, preferably, the system further comprises a valve I and a valve II, and the valve is used for controlling the tail gas of the galvanic pile to enter the reformer; the reformer I is controlled by a valve I; the reformer II is controlled by valve II.

Advantageous effects

In the original starting method, the time required for heating a set of 1kW high-temperature battery system to the working temperature (25 ℃) and discharging at rated power is about 30 minutes, and the power consumption is about 2kW · h. After the method is started, the heating time is shortened to 20-22 minutes, and the power consumption is about 1.4 kW.h. Greatly shortening the starting time and the power consumption.

By adopting the sectional heating, the heat of the electric pile is supplied to the fuel reformer which is not heated for heating, so that the utilization efficiency of the system energy is greatly improved, and the quick start of the system is realized.

Drawings

Fig. 1 is a diagram of a high temperature fuel cell system of the present invention.

FIG. 2 is a schematic diagram of the start-up sequence of the present invention.

Detailed Description

Example 1

A reforming high-temperature fuel cell system comprises a reformer I, a reformer II, a heat exchanger and a stack; the reformer I comprises a combustor I, and the reformer II comprises a combustor II; the reformer I is controlled by a valve I; the reformer II is controlled by valve II.

Example 2

First, the stack and reformer I are started normally, and the burner I and electrical heating are used to provide heat to the system. When the reformer I reaches the working temperature and the galvanic pile reaches the low-power operation temperature, the fuel pump of the reformer I is started to enable the system to work at low power. At the moment, heat exchange is carried out between the circulating medium for providing heat dissipation for the galvanic pile and the reformer II; and simultaneously opening a valve II, performing catalytic combustion in a combustor II by using the tail gas of the anode of the galvanic pile, and providing heat for a reformer II. And when the temperature of the reformer II is consistent with that of the galvanic pile, closing a galvanic pile heat-radiating medium channel entering the reformer II, and only retaining the catalytic combustion of the anode tail gas of the galvanic pile to continuously provide a heat source for the reformer II. When the temperature of the electric pile and the temperature of the reformer II reach the respective rated working temperatures, the valve I is opened and the fuel pump of the reformer II is opened to provide H for the electric pile₂Source, and system rated power output.

Claims

1. A method of starting a reforming high temperature fuel cell system, the method comprising: heating a fuel reformer in stages, wherein the fuel reformer comprises a reformer I and a reformer II; the step of heating in sections is to heat the reformer I and then heat the reformer II by using the heat of the tail gas of the galvanic pile;

starting a galvanic pile and a reformer I, and providing heat for the system by using a combustor I and electric heating; when the reformer I reaches the working temperature and the galvanic pile reaches the low-power operation temperature, starting a fuel pump of the reformer I to enable the system to work at low power, and providing a circulating medium for heat dissipation of the galvanic pile to exchange heat with the reformer II; and meanwhile, the anode tail gas of the galvanic pile is introduced into the combustor II for catalytic combustion, heat is provided for the reformer II, when the temperature of the reformer II is consistent with that of the galvanic pile, a galvanic pile heat-radiating medium channel entering the reformer II is closed, and the catalytic combustion of the anode tail gas of the galvanic pile is kept to continuously provide a heat source for the reformer II.

2. The method of claim 1The method is characterized in that when the temperature of the electric pile and the temperature of the reformer II reach the respective rated working temperatures, a fuel pump of the reformer II is turned on to provide H for the electric pile₂Source, and system rated power output.

3. The method of claim 1, wherein the system comprises a reformer I, a reformer II, a heat exchanger, and a stack; reformer I includes a burner I and reformer II includes a burner II.

4. The method of claim 3, wherein the system further comprises a valve I and a valve II, and the valve is used for controlling the tail gas of the stack to enter the reformer; the reformer I is controlled by a valve I; the reformer II is controlled by valve II.