Catalytic reaction heater

Abstract

A catalytic reaction heater includes a plurality of catalytic reacting sections for generating a high-temperature gas based on a catalytic reaction of fuel and oxygen, and a plurality of heat exchanging sections for increasing the temperature of a circulating heating medium based on heat exchange between the heating medium and the gas. The catalytic reacting sections and the heat exchanging sections are alternately and serially disposed along a flowing direction of the gas. A supply amount of the fuel and oxygen supplied into an upstream end catalytic reacting section is set to a value exceeding a maximum consumable level in this upstream end catalytic reacting section.

Description

BACKGROUND OF THE INVENTION [0001] The present invention relates to a catalytic reaction heater that utilizes a catalytic reaction to obtain heat energy for increasing the temperature of a heating medium. [0002] The catalytic reaction heater includes a catalytic reacting section whose reaction temperature must be controlled so as not to exceed a predetermined temperature level (for example, a heat resisting temperature of the catalyst). The reaction temperature of the catalytic reacting section becomes higher when an excess air ratio (i.e. a ratio of an actually supplied air amount to a theoretically required air amount for complete combustion) approaches to 1. Accordingly, controlling the reaction temperature of the catalytic reacting section is feasible by adjusting the excess air ratio. [0003] Furthermore, to control the temperature of a reacting system, there is a conventional arrangement consisting of a plurality of separated catalytic reacting sections assembled with a plurali...

AI Technical Summary

Benefits of technology

[0006] In view of the above-described problems, the present invention has an object to provide a catalytic reaction heater capable of downsizing an air supplying section as well as suppressing the thermal runaway and eliminating damage of the catalyst.

[0010] Accordingly, even if the oxygen amount supplied to the upstream end catalytic reacting section is set to be closer to the theoretical air-fuel ratio, the reaction temperature rise at each catalytic reacting section is small. In other words, there is no necessity of increasing the excess air ratio to a higher value exceeding 1 to suppress the reaction temperature to a low temperature. The air supplying section can be downsized. Furthermore, each catalytic reacting section can suppress its reaction temperature to a predetermined lower temperature. Therefore, the first catalytic reaction heater suppresses the thermal runaway and accordingly prevents the catalyst from being damaged.

[0012] According to the second catalytic reaction heater of the present invention, the fuel is separately supplied to each catalytic reacting section. Therefore, even if the oxygen amount supplied to the upstream end catalytic reacting section set to be closer to the theoretical air-fuel ratio, the excess air ratio of each catalytic reacting section can be set to a higher value exceeding 1. Each catalytic reacting section can suppress its reaction temperature to a predetermined lower temperature. Therefore, the second catalytic reaction heater realizes a downsizing of the air supplying section. Furthermore, the second catalytic reaction heater suppresses thermal runaway and accordingly prevents the catalyst from being damaged.

[0014] According to the third catalytic reaction heater of the present invention, the oxygen is separately supplied to each catalytic reacting section. Therefore, the third catalytic reaction heater can reduce the excess air ratio to a lower value smaller than 1 so as to suppress the reaction amount in each catalytic reacting section. Furthermore, the third catalytic reaction heater can release the reaction heat to the non-reacted fuel. Each catalytic reacting section can suppress its reaction temperature to a predetermined lower temperature. Therefore, the third catalytic reaction heater realizes downsizing of the air supplying section. Furthermore, the third catalytic reaction heater suppresses thermal runaway and accordingly prevents the catalyst from being damaged.

[0015] Furthermore, in any one of the above-described first to third catalytic reaction heaters of the present invention, it is preferable that one of the catalytic reacting sections and one of the heat exchanging sections are serially disposed in one casing so as to constitute each one of a plurality of units connected to each other. According to this arrangement, assembling the manufactured components is easy. Changing the reaction amount is easily feasible by changing the total number of units to be combined.

Problems solved by technology

On the other hand, according to the latter catalytic reaction heater, it is impossible to control the temperature at a catalytic reacting section disposed at the upstream end (hereinafter, referred to as “upstream end catalytic reacting section”) and accordingly there is the possibility that the upstream end catalytic reacting section may cause an excessive amount of catalytic reaction which possibly induces thermal runaway and as a result may damage the catalyst.

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