BCHP System For Commercial Buildings

Cogeneration systems are used in many commercial buildings today. These systems have an engine that is used to produce electrical power by driving a generator and some form of heat recovery on the engine exhaust and cooling jacket. This project was focused on developing a cogeneration system for grocery stores where the engine was a natural-gas fired turbine.

Turbines produce more power if the inlet air is dense. During the winter months, a turbine generator would produce more electricity than it would in hotter months. One way to improve summer power generation is to cool the inlet air. During this project, an ammonia absorption system was used to provide turbine inlet air cooling (TIAC). The heat input for the cooling system came from the turbine exhaust flow.

A system model was developed where all of the system components were analytically represented along with the temperature and pressure dependent performance parameters. This model was used with hourly weather data to predict system performance in various locations around the country.

A significant improvement in turbine power output was predicted by the model in hot, dry locations such as Phoenix, and modest, but cost effective improvements were seen in other regions.

A system was prototyped and tested to demonstrate the technology. Test results validated the model.