SIMULATION OF COOLING AIR PROCESSES WITH ACCUMULATION AND USING A SURPLUS EJECTOR CHILLER REFRIGERATION CAPACITY IN BUSTER AIR COOLER

Abstract

The heat-humidity processes of gas turbine unit intake air deep cooling to the temperature of 10 °C and lower with the use of refrigerant boiling at the temperature of about 4-6 °C as a coolant and the ejector chiller utilizing the turbine exhaust gas waste heat as a thermotransformer has been analyzed for daily changing ambient air temperatures and changeable heat loads on the air cooler as consequence. The computer programs of the firms-producers of heat exchangers were used for gas turbine unit intake air cooling processes simulation. It is shown that at decreased heat loads on the air cooler a surplus refrigeration capacity of the ejector chiller exceeding current heat loads is generated which can be used for covering an increased heat loads on the air cooler and to reduce the refrigeration capacity of the ejector chiller applied. To solve this task the refrigeration capacity required for gas turbine unit intake air cooling are compared with the surplus refrigeration capacity of the ejector chiller exceeding current heat loads summarized during some time period.

The system of two-stage gas turbine unit intake air cooling of combined type with a buster water stage of precooling air to the temperature of about 15 °C and refrigerant stage of further deep cooling air to the temperature of about 10 °C by refrigerant ejector chiller as the low temperature cooling stage has been proposed. The water for a buster stage of precooling air is cooled by using the surplus refrigeration capacity of the ejector chiller during decreased heat loads on the two-stage gas turbine unit intake air cooler and is collected in the thermal accumulator for the use during increased heat loads on the air cooler. The results of gas turbine unit intake air cooling processes simulation proved the reduction of refrigeration capacity of the ejector chiller applied by 30-40 % due to the use of a buster water stage of precooling air at the expanse of the surplus ejector chiller refrigeration capacity served in the thermal accumulator. So the main conclusion has been made about the efficient use of such a two-stage air cooling of combined type with a buster water stage of precooling air by surplus refrigeration capacity from the thermal accumulator and refrigerant stage for further deep cooling air to the temperature of about 10 °C and lower by a refrigerant chiller as the low temperature cooling stage as a perspective approach in refrigeration.