Modeling of Combined Heat and Power Cycle based on Micro Gas Turbines using Biogas Fuel: an Investigation of Key Parameters

Distributed electricity generation has been a long-standing focus for researchers and policy-makers. With the global rise in electricity demand, various generation methods such as solar, wind, fuel cells, and internal combustion engines-are being implemented, each with distinct advantages and drawbacks. Micro gas turbines have emerged as a viable candidate for a reliable, cost-effective, and accessible energy production system. To enhance overall system efficiency, the heat produced from fuel combustion in these turbines can also be used to generate hot water. This study investigates micro gas turbines fueled by biogas, analyzing the effects of several critical parameters: Turbine Inlet Temperature (TIT), Compressor Pressure Ratio (CPR), and recuperator effectiveness within the cycle. The thermodynamic modeling uses the thermally perfect gas model and was conducted in EES (Engineering Equation Solver), with a selected commercial gas microturbine used for validation. Variable fluid thermodynamic properties are accounted for based on temperature, providing accuracy under diverse operational scenarios. It is found that to achieve the maximum overall efficiency; there is an optimal value for the CPR, while it increases with increment in the TIT and recuperator effectiveness.