| 摘要 |
PURPOSE:To improve the setting up characteristics of a heater after an engine is started by providing both a main hot water circuit in which cooling water runs from the engine through both a preheater and a main heat-exchanger to the engine and a sub hot water circuit in which cooling water runs from the engine through a sub heat- exchanger to the engine. CONSTITUTION:In a heater of a bus or like, the cooling water outlet part of an engine 1 is connected to a radiator 2 via a thermostat 3. A main hot water circuit 10 in which cooling water (or hot water) is sent by the operation of a heating water pump 6 from a shut-off valve 5 to pass through a burning type preheater 7 and a main heat- exchanger 8 and then fed to a hot water return port 9 which is disposed at the cooling water inlet part of the engine 1 is connected to the heating hot water take-out port 4 disposed at said outlet part. And a sub hot water circuit 12 which is separated from the main circuit 10 at the upstream side point of the preheater 7 thereof, passes through a sub heat-exchanger 11 and then is combined with the main hot water circuit 10 at the lower current side of the main heat-exchanger 8 is connected the main hot water circuit 10. The temperature of hot water at the inlet of the main heat-exchanger 8 is controlled to maintained equally or higher than the temperature of hot water at the inlet of the sub heat-exchanger 11. |
