Investigating the effects of integrating an absorption heat transformer with a combined cooling, heating and power system: A thermodynamic and economic analysis

Highlights: • Proposing a new CCHP system integrated into absorption heat transformer. • Improving the performance and energy consumption in the proposed system. • Using natural gas in the heat source, carbon emissions are reduced by 1056.3 ton/year. • Comparing with the conventional CCHP system, the energy is reduced 2271.6 MWh/year. Regarding the significance of low-temperature heat sources in combined cooling, heating, and power (CCHP) systems, it is necessary to find practical and economical ways to maximize the efficient use of available energies. Integrating the auxiliary cycle with the main system and changing the configuration are among the useful solutions to achieve this purpose. In this work, a combination of both solutions is presented, accordingly, an absorption heat transformer cycle (AHT) is integrated with a conventional CCHP system, which is made of organic Rankine cycle, absorption refrigeration cycle, and a heat exchanger. Three conventional CCHP systems with sequential (Configuraion₁), parallel (Configuraion₂) and a combination of sequential and parallel (Configuraion₃) configurations are considered. It is shown that among the Configuraion₁, Configuraion₂, and Configuraion₃, Configuraion₁ has the highest energy efficiency; therefore, it is selected to be compared with the proposed integrated system with AHT. This integration affects the outputs production and also energy consumption; therefore, four different modes (standpoints) are taken into account to compare the production of power (mode A), cooling (Mode B), heating (mode C), and energy consumption (mode D) of these two systems. Also, from the exergy, environmental, and economic aspects, these two systems are compared. Regarding mode D, it is indicated that the energy and exergy efficiencies, energy consumption and carbon emission of the proposed system are improved 17.68%, 17.68%, 15.03%, and 15.02%, respectively. It is noted that for the heat source stream temperature range of 90 °C–120 °C, the proposed system has better performance than the Configuration₁. Despite the additional costs of integrating AHT with the CCHP system, the proposed system has 517018.1 US$/year cost saving (which is 32.65% of the investment cost of Configuration₁) if biomass is used as a heat source, which indicates its higher economic advantage than the Configuration₁. Also, comparing the proposed system with Configuration₁, the amount of power, cooling and heating productions are improved 27.98%, 102.15%, and 36.87%, respectively.