Fuel cell cogeneration system, method of starting operation of the fuel cell cogeneration system, and method of operating the fuel cell cogeneration system

Patent metadata

Field	Value
Publication number	US-10020521-B2
Application number	US-201615231956-A
Country	US
Kind code	B2
Filing date	Aug 9, 2016
Priority date	Aug 13, 2015
Publication date	Jul 10, 2018
Grant date	Jul 10, 2018

Abstract

A fuel cell cogeneration system includes a fuel cell module, a heat exchanger, a hot water tank, a circulating water channel, and an oxygen-containing gas supply channel. A circulating water heater for heating water is provided on the circulating water channel. Part of the oxygen-containing gas supply channel is provided in the circulating water heater to thereby allow air flowing through the oxygen-containing gas supply channel to be heated by receiving heat from the circulating water heater.

First claim

What is claimed is:

1. A fuel cell cogeneration system comprising:
a fuel cell module configured to generate electric power by electrochemical reactions of a fuel gas and an oxygen-containing gas;
a heat exchanger configured to heat water by heat exchange with exhaust heat discharged from the fuel cell module to thereby produce hot water;
a hot water tank configured to discharge the water and store the hot water;
a circulating water channel configured to send the water discharged from the hot water tank to the heat exchanger, and return the hot water obtained in the heat exchanger to the hot water tank; and
an oxygen-containing gas supply channel configured to supply the oxygen-containing gas to the fuel cell module,
wherein the heat exchanger is provided on the circulating water channel, heats the water coming in from the circulating water channel by heat exchange with exhaust heat discharged from the fuel cell module to thereby produce the hot water, and includes a circulating water heater provided on a downstream side of the heat exchanger on the circulating water channel and configured to heat the water,
wherein part of the oxygen-containing gas supply channel is provided in the circulating water heater to thereby allow the oxygen-containing gas flowing through the oxygen-containing gas supply channel to be heated by receiving heat from the circulating water heater,
wherein the fuel cell module includes a steam reformer configured to reform a mixed gas of a raw fuel and water vapor to thereby produce the fuel gas, and supply the fuel gas to the fuel cell module,
wherein a reforming water chamber housing a reforming water tank is provided, the reforming water tank being configured to store reforming water for producing the water vapor, and
wherein the oxygen-containing gas supply channel includes a bypass channel that diverges from the oxygen-containing gas supply channel at a diverging point provided midway in the oxygen-containing gas supply channel, extends through the reforming water chamber, and then merges with the oxygen-containing gas supply channel.

2. The fuel cell cogeneration system according to claim 1 , wherein a switching valve configured to allow the oxygen-containing gas to be supplied to the bypass channel is provided at the diverging point.

3. The fuel cell cogeneration system according to claim 1 , further comprising an electrical equipment unit configured to control electric power,
wherein the electrical equipment unit includes:
an air intake port configured to take an external air into the electrical equipment unit; and
an electrical-equipment-unit-side oxygen-containing gas supply channel configured to supply the air taken into the electrical equipment unit to the fuel cell module through the oxygen-containing gas supply channel or separately from the oxygen-containing gas supply channel.

4. A method of starting operation of a fuel cell cogeneration system, the fuel cell cogeneration system comprising:
a fuel cell module configured to generate electric power by electrochemical reactions of a fuel gas and an oxygen-containing gas;
a steam reformer configured to reform a mixed gas of a raw fuel and water vapor to thereby produce the fuel gas, and supply the fuel gas to the fuel cell module;
a reforming water chamber housing a reforming water tank configured to store reforming water for producing the water vapor;
a heat exchanger configured to heat water by heat exchange with exhaust heat discharged from the fuel cell module to thereby produce hot water;
a hot water tank configured to discharge the water and store the hot water;
a circulating water channel configured to send the water discharged from the hot water tank to the heat exchanger, and return the hot water obtained in the heat exchanger to the hot water tank;
a circulating water heater provided on the circulating water channel and configured to heat the water;
an oxygen-containing gas supply channel configured to supply the oxygen-containing gas to the fuel cell module; and
a bypass channel that diverges from the oxygen-containing gas supply channel, extends through the reforming water chamber, and then merges with the oxygen-containing gas supply channel,
wherein the heat exchanger is provided on the circulating water channel, heats the water coming in from the circulating water channel by heat exchange with exhaust heat discharged from the fuel cell module to thereby produce hot water,
the method comprising the steps of:
determining whether or not operation of the fuel cell module has been started;
if it is determined that operation of the fuel cell module has been started, determining whether or not a temperature of the reforming water chamber is a predetermined temperature or less;
if it is determined that the temperature of the reforming water chamber is the predetermined temperature or less, turning on the circulating water heater, and opening the bypass channel to the oxygen-containing gas supply channel so that the oxygen-containing gas flowing from the bypass channel into the reforming water chamber is returned from the reforming water chamber to the oxygen-containing gas supply channel and then is supplied to the fuel cell module; and
if it is determined that the temperature of the reforming water chamber is not the predetermined temperature or less, turning on the circulating water heater, closing the bypass channel with respect to the oxygen-containing gas supply channel, and supplying directly the oxygen-containing gas from the oxygen-containing gas supply channel to the fuel cell module without the oxygen-containing gas entering from the bypass channel to the reforming water chamber.

5. The method of starting operation of the fuel cell cogeneration system according to claim 4 , wherein air taken into an electrical equipment unit configured to control electric power is supplied to the fuel cell module through the oxygen-containing gas supply channel or supplied to the fuel cell module separately from the oxygen-containing gas supply channel.

6. A method of operating a fuel cell cogeneration system, the fuel cell cogeneration system comprising:
a fuel cell module configured to generate electric power by electrochemical reactions of a fuel gas and an oxygen-containing gas;
a steam reformer configured to reform a mixed gas of a raw fuel and water vapor to thereby produce the fuel gas, and supply the fuel gas to the fuel cell module;
a reforming water chamber housing a reforming water tank configured to store reforming water for producing the water vapor;
a heat exchanger configured to heat water by heat exchange with exhaust heat discharged from the fuel cell module to thereby produce hot water;
a hot water tank configured to discharge the water and store the hot water;
a circulating water channel configured to send the water discharged from the hot water tank to the heat exchanger, and return the hot water obtained in the heat exchanger to the hot water tank;
an oxygen-containing gas supply channel configured to supply the oxygen-containing gas to the fuel cell module; and
a bypass channel that diverges from the oxygen-containing gas supply channel, extends through the reforming water chamber, and then merges with the oxygen-containing gas supply channel,
wherein the heat exchanger is provided on the circulating water channel, heats the water corning in from the circulating water channel by heat exchange with exhaust heat discharged from the fuel cell module to thereby produce hot water, and includes a circulating water heater provided on a downstream side of the heat exchanger on the circulating water channel and configured to heat the water,
the method comprising the steps of:
determining whether the fuel cell module is in a steady operating state;
if it is

Assignees

• Honda Motor Co Ltd

Inventors

• Yamamoto Takeyoshi

Classifications

• H01M2008/1293

  Fuel cells with solid oxide electrolytes · CPC title

• H01M8/04029 Primary

  Heat exchange using liquids · CPC title

• H01M8/04007 Primary

  related to heat exchange · CPC title

• H01M8/04052

  Storage of heat in the fuel cell system · CPC title

• H01M8/04268 Primary

  Heating of fuel cells during the start-up of the fuel cells · CPC title