Abstract: Coal-based energy structure has resulted in serious pollution in China, so it is necessary to implement a clean and efficient district heating system. Decreasing the return water temperature of the heat network can not only widen the temperature difference between supply and return water, reduce the investment in pipeline network and power consumption of water pumps, but also create a favourable condition for the waste heat recovery of low-temperature, which can enhance the feasibility of the district heating. Therefore, a novel large temperature-difference heat exchange system based on hot water and gas driven absorption heat pumps is constructed, which substantially reduces the primary return water temperature while realizing the combination of clean coal-fired cogeneration and gas peak shaving. Considering the economics of investment and operation of the new heating system, the key parameters of two absorption heat pumps under different working conditions are optimized. Compared with the conventional system, the comprehensive exergy efficiency is improved by 29.2%, the heating capacity of the combined heating and power plant is enhanced by 47.5%, and the comprehensive costs per unit heat output are decreased by 18.6%. The results mentioned above are also used to guide and promote the construction of new district heating systems with a higher energy efficiency and feasibility.