| 摘要 |
<p>PROBLEM TO BE SOLVED: To efficiently cope with frequent variation of combustion output and variable width of the combustion output by constituting a heat source unit for refrigerant heating with a catalyst combusting mechanism for conducting multistage combustion at a plurality of catalytic bodies. SOLUTION: Preheaters 25a, 25b are applied with current at the time of starting combustion to preheat a first catalytic body 26 up to not less than an activation temperature, i.e., approximately up to 350 deg.C. Thereafter, current application to the preheaters 25a, 25b are stopped, followed by supplying thereto a premixed gas from a supply portion to start catalytic combustion at the first catalytic body 26. Then a second catalytic body 29 is heated by the exhaust heat from the first catalytic body 26 to start combustion at the second catalytic body 29 as well. Combustion is conducted almost completely at the first and second catalytic bodies 26, 29 during the catalytic combustion. Slightly remaining uncombusted exhaust gas that has passed through the second catalytic body 29 is purified at a third catalytic body 31.</p> |
