SIMULATION OF COOLING AIR PROCESSES BY ABSORPTION LITHIUM-BROMIDE CHILLER WITH USING A SURPLUS REFRIGERATION CAPACITY IN BUSTER AIR COOLER

Abstract

The heat-humidity processes of gas turbine unit intake air cooling to the temperature of above 15 °C with the use of a cold water at the temperature of about 10 °C as a coolant and the absorption lithium-bromide 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 coolers 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 cooling capacity of the absorption lithium-bromide 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 cooling capacity of the absorption lithium-bromide chiller applied. To solve this task the cooling capacity required for gas turbine unit intake air cooling are compared with the surplus cooling capacity of the absorption lithium-bromide chiller exceeding current heat loads summarized during some period.

The system of two-stage gas turbine unit intake air cooling with a buster stage of precooling air to the temperature of about 15 °C and a base stage of further cooling air to the temperature of about 15 °C by absorption lithium-bromide chiller as the base stage has been proposed. The water for a buster stage of precooling air is cooled by using the surplus cooling capacity of the absorption lithium-bromide 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 cooling capacity of the absorption lithium-bromide chiller applied by 30-40 % due to the use of a buster stage of precooling air at the expanse of the surplus cooling capacity of absorption lithium-bromide chiller saved in the thermal accumulator. So the main conclusion has been made about the efficient use of such a two-stage air cooling with a buster stage of precooling air by surplus cooling capacity from the thermal accumulator and a base stage for further cooling air to the temperature of about 15 °C by an absorption lithium-bromide chiller as a perspective approach in refrigeration.