A new type of district heating (DH) method based on Co-ah cycle was designed to improve both the capacity of heating system and the energy efficiency of Cogeneration plant. In the DH system substations, the temperature of return water of the primary heat network is reduced to about 25 C through the absorption heat-exchange units. In the thermal station of the Cogeneration plant, the return water of the primary heat network is heated orderly by the exhaust steam in the condenser, the absorption heat pumps and the peak load heater. Compared with the traditional DH methods, this system runs with a greater circuit temperature drop so that the delivery capacity of the heat network increases dramatically. The heating capacity and the energy efficiency of the Cogeneration plant is significantly increased by the exhausted heat recovery from the condensers. A remarkable economic advantage can be achieved in this technology. At present, an application demonstration project had been built up in Chifeng city of Inner Mongolia Autonomous Region in north China. (C) 2010 Elsevier Ltd. All rights reserved.