District heater include two types which are basic district heater and peak district heater. The working principle of the district heater is to heat the water flowing to the heating net system of the power plant. The heated steam is from the turbine exhaust under higher pressure. The new steam after temperature reducing and pressure reducing from the boiler can be also used as steam source. The temperature of the heating net system water can be improved to the required water supplying temperature by the heated steam.
The basic district heater can operate during the whole heating supplying period. It can meet the most of requirement to the water temperature during the heating supplying period. During the coldest period of the winter since the water temperature for heating supply is higher so the water of the basic district heater can be entered into the peak district heater connected with it.