Efficiency Improvement and Cost Analysis of a New Combined Absorption Cooling and Power System

Abstract

AbstractSerious concerns like population growth, environmental pollution due to excessive waste disposal, fossil fuels consumption in order to provide high energy demands, global warming, ozone depletion, and acid rainfalls have led energy policymakers to recommend solutions to resolve these challenges. In this regard, the cogeneration of electricity and cooling is a technology to solve the mentioned formidable obstacles. The present study introduces a practical but straightforward simultaneous power and cooling plant executed by a natural gas-fired open Brayton cycle. The bottoming process utilizes an ammonia-water mixture. To be more specific, the thermodynamic and thermoeconomic model of the process was assessed in the engineering equation solver (EES). The effect of the significant variables of the proposed cycle is also studied based on the overall system performance criteria. As a result, the highest exergy destruction is for the Brayton cycle, 44.89% of the total irreversibility, followed by the boiler and mixer in the absorption cycle, and the smallest amount of irreversibility belongs to the evaporator, with 0.14%. The parametric study results demonstrate that minimizing the air temperature entering the combustor will improve the studied system. To deduce, the cogeneration unit is optimized based on the second law efficiency as an objective function. In turn, the optimization results illustrate an enhancement in exergy efficiency and unit cost of products by 21.73% and 4.13%.KeywordsGas turbineGoswami cycleCombined cooling and power (CCP)Exergoeconomic analysisEfficiency enhancement