Warm-up device for catalytic reactor

Abstract

A fuel cell power plant is provided with a reformer ( 18 ) producing a reformate gas and a carbon monoxide removal device ( 1 ) removing carbon monoxide from the reformate gas as a result of catalytic reactions. When the carbon monoxide removal device ( 1 ) is operating at a low temperature, a heat exchanger ( 10 ) supplies gaseous heat transmitting medium to a heat exchange portion ( 5 ) of the carbon monoxide removal device ( 1 ) and warms the catalyst using heat exchange operations with the catalyst in the carbon monoxide removal device ( 1 ). The pressure regulation valve ( 12 ) regulates the pressure of the gaseous heat transmitting medium and maintains the temperature of the catalyst between the catalyst activation temperature and the predetermined upper limiting temperature of the catalyst in order to employ latent heat resulting from the heat of condensation of the steam for heating the catalyst.

What is claimed is:  
     
         1 . A warm-up device for a catalytic reactor performing a predetermined chemical reaction mediated by a catalyst activated at a predetermined activation temperature, the warm-up device comprising: 
 a vapor supply mechanism supplying gaseous heat transmitting medium;    a heat exchange portion performing heat exchange operations between the catalyst and the gaseous heat transmitting medium;    a pressure control valve regulating a pressure of the gaseous heat transmitting medium in the heat exchange portion; and    a passage recirculating the heat transmitting medium condensed in the heat exchange portion.    
     
     
         2 . The warm-up device as defined in  claim 1 , wherein the recirculation passage is provided with a tank storing the heat transmitting medium.  
     
     
         3 . The warm-up device as defined in  claim 1 , wherein the heat transmitting medium comprises an aqueous solution of ethylene glycol.  
     
     
         4 . The warm-up device as defined in  claim 1 , wherein the vapor supply mechanism has a function of supplying the heat transmitting medium in a liquid state to the heat exchange portion  5  so as to absorb a heat of the catalyst in the heat exchange portion, and the warm-up device further comprises a radiator which radiates heat from the heat transmitting medium.  
     
     
         5 . The warm-up device as defined in  claim 1 , wherein the catalytic reactor comprises a carbon monoxide removal device adapted to be used in a fuel cell power plant for producing a hydrogen-rich gas by removing carbon monoxide from a reformate gas, the fuel cell power plant comprising a fuel cell stack which generates electric power using the hydrogen-rich gas, and a reformer producing the reformate gas by reforming a hydrocarbon fuel.  
     
     
         6 . The warm-up device as defined in  claim 5 , wherein the reformer comprises a device producing the reformate gas by steam reforming operations on the hydrocarbon fuel, the heat transmitting medium comprises water, the vapor supply mechanism has a function of supplying water in a liquid state to the heat exchange portion, and the warm-up device further comprises a valve supplying the reformer with steam produced by evaporation of the water in the heat exchange portion by a heat of the catalyst.  
     
     
         7 . The warm-up device as defined in  claim 6 , wherein the vapor supply mechanism comprises a pre-heater preheating water, and the warm-up device further comprises a sensor detecting a power generation load on the fuel cell stack, and a controller functioning to calculate a heat amount required for generating a required amount of steam which is to be supplied to the reformer based on the power generation load, calculate a reaction heat amount produced in the carbon monoxide removal device when the required amount of steam is supplied to the reformer and a corresponding amount of the reformate gas is supplied to the carbon monoxide removal device, and control the pre-heater according to a difference between the required heat amount and the produced heat amount.  
     
     
         8 . The warm-up device as defined in  claim 1 , wherein the vapor supply mechanism comprises a heater heating the heat transmitting medium and a pump supplying the heat transmitting medium to the heater.  
     
     
         9 . The warm-up device as defined in  claim 1 , wherein the warm-up device further comprises a sensor detecting a temperature of the catalyst and a controller functioning to reduce an opening of the pressure control valve when the temperature of the catalyst is lower than the activation temperature in order to maintain a condensation temperature of the heat transmitting medium to a value between the catalyst activation temperature and a predetermined upper limiting temperature for the catalyst.  
     
     
         10 . The warm-up device as defined in  claim 9 , wherein the warm-up device further comprises a sensor detecting an oxygen concentration of an atmosphere around the catalyst and the controller further functions to perform a determination as to whether the atmosphere around the catalyst is an oxidizing environment or a reducing environment based on the oxygen concentration, and to set the upper limiting temperature for the catalyst to different values according to a result of the determination.