AUXILIARY HEATING APPARATUS USING EXHAUST GAS HEAT OF ENGINE, FORMING CLOSED CIRCUIT WHILE USING PRE-HEATER AND OPENING COOLING WATER CIRCULATION WHILE NOT USING PRE-HEATER

PURPOSE: An auxiliary heating apparatus using exhaust gas heat of an engine, forming a closed circuit while using a pre-heater and opening cooling water circulation while not using the pre-heater is provided to improve immediate effect of heating and remove equipment for controlling a pressure of an auxiliary heat exchanger. CONSTITUTION: An auxiliary heating element(300) is formed of a pre-heater(310) installed next to a heater core(140) for receiving supply of cooling water, and an auxiliary heat exchanger(320) installed in the middle of an exhaust pipe(210) of an engine(200) to supply heated cooling water to the pre-heater. A multi-valve element(400) connects an engine inlet pipe and an engine outlet pipe(302) extended from the engine, a core inlet pipe(303) and a core outlet pipe extended from the heater core, an auxiliary outlet pipe(306) extended from the pre-heater, and an auxiliary inlet pipe(305) connected to the auxiliary heat exchanger. The multi-valve element includes a first valve opening and shutting a flow of cooling water supplied from the engine outlet pipe to the auxiliary inlet pipe or to the core inlet pipe, and a second valve opening and shutting a flow of the auxiliary outlet pipe or the core outlet pipe to be connected to the engine inlet pipe. An actuator drives the first valve and the second valve.