Using cogeneration systems is a great way to tackle fossil fuel consumption problems. This paper introduces a Combined Cooling Heating Power (CCHP) system to recover the waste heat of an RK215 heavy diesel engine as a prime mover. Therefore the CCHP system consists of Internal Combustion Engine (RK215), a heat storage tank, and an absorption chiller. Also, the system has been studied in four modes: CCHP, CHP, CCP, and single generation. The waste heat ratio has changed due to a y factor, and the effect of this different parameter, such as the start of fuel injection and exhaust gas heat, on the system's efficiency by considering first and second laws of thermodynamic in different operating modes has been investigated. The system's highest energy and exergy efficiency in CCHP mode is equal to 50.46 and 30.8%, respectively. According to the result, as the CCHPs cooling load to the absorption chiller increases, the performance also rises. Also, the system’s carbon dioxide emissions reduction has been studied. The results showed that using different modes for waste heat recovery can reduce carbon dioxide by up to 30% approximately for different modes. Also, the fuel energy saving ratio (FESR) has been investigated, and the results showed that systems in CCHP, CHP, and CCP modes could have FESR approximately equal to 21%.

This study evaluates the utilization of waste heat from a polymer electrolyte membrane fuel cell (PEMFC) across four scenarios: combined heat and power (CHP), combined cooling, heating, and power (CCHP), combined cooling and power (CCP), and hybrid power generation with an organic Rankine cycle (ORC). The methodology involves thermodynamic modelling and parametric analysis to assess energy efficiency, fuel savings, and environmental impact. The CCHP scenario demonstrates the highest overall system efficiency of 87%, achieving 46% fuel savings and a 55% reduction in CO₂ emissions. The ORC scenario, leveraging waste heat for hybrid power generation, achieves an electrical efficiency of 41% and an overall efficiency of 68%, with 26% fuel savings and a 49% CO₂ emissions reduction. This study reveals that integrating CCHP systems provides superior performance across energy, environmental, and economic metrics. The findings contribute to advancing sustainable energy systems by optimizing waste heat recovery, reducing emissions, and providing tailored solutions based on consumer demands and operational conditions.

This paper describes a study that starts with an analysis of typical energy demand profiles in a hospital setting followed by a case study of a combined cooling, heating, and power (CCHP) generation system. CCHP is an autonomous system that combines the generation of electrical, heating, and cooling energy. The driving units are two high-efficiency gas engines that produce electrical and heat energy. A gas engine meets the high electrical and heating energy demand requirements - a natural gas-fueled reciprocating engine generates 735 kW of power. In our case, the electrical energy was used only in the hospitals. Purchasing power from the public network covers deficits in the required electricity. Generated steam drives three steam-fired absorption chillers and provides heat for individual consumers; thus, the system provides simultaneous heating and cooling. Implementing the CCHP system did not identify any technical obstacles. The hourly energy demands during several seasons throughout the year determined the typical patterns for CCHP driving units. The average ratio between electric and thermal loads in the hospital is suitable for operating the CCHP system. An analysis performed for an improved CCHP system predicted a large potential for energy savings and CO2 reduction.