Ammonia binary cycle with dry cooling for power plants

Abstract

Dry cooling with air of thermal, conventional or nuclear power plant makes it possible to generate power close to utility centres, even when water is not available there. But dry cooling has drawbacks such as lower cycle efficiency, high cost of the cold source and major generation losses in summer, due to high temperatures of the cold source of the cycle. The binary cycle is derived from a conventional cycle by replacing the end of the low pressure steam expansion by a bottoming cycle. The combined system has been analysed using ammonia in a bottoming cycle and steam in a topping cycle. The power output, cycle efficiency, and combined cycle efficiency have been compared keeping a variation in steam turbine exhaust pressure and ambient temperature. It has been observed that the binary cycle plant has advantages over the conventional dry plant, as it does not need shutting down in summer, and makes better use of cold source. In cold weather, a large increase in power is obtained per degree of ambient temperature reduction.