Simulation of combined heat and power in an acidification process using Nanofluids

Highlights: • CHP system is simulated in an acidifier company located in Zanjan. • Thermal losses of acidification process are used as inputs of the CHP cycle. • Nanofluids are used as working fluids of the employed heat exchangers in the CHP cycle. • The proposed CHP cycle is proved to produce extra power of 2.275 MW with 66.24% total efficiency. • The acidifier with CHP is independent of national grid, and can sell surplus electricity to the grid. • Economic analysis shows that the payback period is estimated about 5.43 years. Improving the energy efficiency of manufacturing facilities, buildings, and homes can be helpful in meeting energy challenges affordably. Combined heat and power (CHP) systems are strong examples of how energy-efficiency technologies can help achieve significant benefits for end-user facilities, utilities, and communities. Use of CHP systems in the industries with significant thermal losses are more suitable. One of those industries are acidifiers. In this study, CHP system is simulated in an acidifier company located in Zanjan. First, the required amount of heat and power for the acidification process is calculated and then by use of thermal dissipations, as the input of the CHP cycle, the CHP system performance and effectiveness is calculated. To improve the efficiencies of heat exchangers in the CHP cycle, Nano-fluids are applied instead of pure working fluids. It will be shown that CuO-water Nano-fluid provides the best thermal efficiency among the considered Nano-fluids. The simulation results demonstrate that the proposed CHP cycle in addition to providing the definitive heat and power required by the acidification process, also produced the extra power of 2.275 MW. This means that; indeed, the acidifier site does not need to receive electricity from the national grid. It has the possibility of selling surplus electricity to the grid. The payback period is estimated about 5.43 years.