The performance investigation of a temperature cascaded cogeneration system equipped with adsorption desalination unit

摘要

This paper presents the performance investigation of a temperature cascaded cogeneration plant, shortly in TCCP, equipped with an efficient waste heat recovery system. The TCCP or cogeneration system produces four types of useful energy namely (ⅰ) electricity, (ⅱ) steam, (ⅲ) cooling, and (ⅳ) dehumidification and distilled water by utilizing single energy source. The TCCP comprises a Capstone C30 micro-turbine that generates nominal capacity of 26 kW of electricity, a compact and efficient waste heat recovery system and a host of waste heat-activated devices namely (ⅰ) a steam generator, (ⅱ) an absorption chiller, (ⅲ) an adsorption desalination system, and (ⅳ) a multi-bed desiccant dehumidifier. The analysis is performed under different operation conditions such as heat source temperatures, flow rates of heat transfer fluids and chilled water inlet temperatures. The only single heat source for TCCP is obtained from exhaust gas of micro-turbine and it is channeled to a series of waste heat recovery heat exchangers to steam and hot water at different temperatures. Hot water produced by such a compact heat exchangers is the driving heat source to produce steam of 15 kg/h, cooling of 2 Rton, dehumidification of 2 Rton, and distilled water of 0.7 m~3/day. A set of experiments, both part load and full load, of micro-turbine is conducted to examine the electricity generation and the exhaust gas temperature. It is observed that energy utilization factor could achieve as high as 70% while fuel energy saving ratio is found to be 28%.