Modeling and Thermo-economic Performance Analysis of a Trigeneration ORC Based System Driven by Condensing Boiler Hot Water Heat Source

In this research, the trigeneration cycle including regenerative Organic Rankine Cycle, liquified natural gas cold energy, and absorption refrigeration system is simulated by applying condenser boiler hot water from the perspective of energy and exergy-economy. In the proposed cycle, medium temperature water leaving the condensing boiler is used as the heat sources of ORC, LNG cold energy, and absorption refrigeration cycle and then returns to the boiler. The effects of various parameters such as boiler outlet temperature, condenser temperature, generator temperature, evaporator temperature as well LNG turbine pressure on the energy and exergy efficiencies, COP, exergy destruction rate, and total cost rate of the system is investigated. The results indicated that increasing boiler outlet temperature leads to the increase of exergy destruction rate while the decrease of energy and exergy efficiencies. First and second law efficiencies will increase as the condenser temperature, generator and evaporator temperatures, and LNG turbine pressure increase. From economic analysis, it was found that by increasing boiler temperature, the overall system cost rate increases. LNG heat exchanger, ORC condenser, and boiler are components that should be considered as they have the highest exergy destruction.