Thermodynamics Performance Analysis of Solar Stirling Engines

Abstract

This paper provides numerical simulation and thermodynamic analysis of SOLO 161 Solar Stirling engine. Some imperfect working conditions, pistons' dead volumes, and work losses are considered in the simulation process. Considering an imperfect regeneration, an isothermal model is developed to calculate heat transfer. Hot and cold pistons dead volumes are accounted in the work diagram calculations. Regenerator effectiveness, heater and cooler temperatures, working gas, phase difference, average engine pressure, and dead volumes are considered as effective parameters. By variations in the effective parameters, Stirling engine performance is estimated. Results of this study indicate that the increase in the heater and cooler temperature difference and the decrease in the dead volumes will lead to an increase in thermal efficiency. Moreover, net work has its maximum value when the angle between two pistons shaft equal to 90 degrees while efficiency is maximum in 110 degrees.

Thermodynamic Analysis of the Stirling Duplex Machine

“…The basic parameters and simulation conditions are presented in Table 1. The geometric dimensions are those of a Stirling engine used by A. Asnaghy et al in their work in 2012 [13] These works, represented numerically by the curved areas in the P-V diagram, are called the indicated works of the machine. Table 2 shows the characteristics and performance of the Stirling machine for one operating cycle.…”

“…In this study, several parameters of the Stirling Duplex machine are discussed. The working fluid considered is helium for its thermal characteristics (high heat transmission capacity) and chemical characteristics (stability) [13]. The adiabatic model used, based on the work of W. Martini [9] and L. Penswick [7], made it possible to highlight these studied parameters, such as the average pressures in the two sections of the machine, the different volumes depending on the position of the power piston, the temperatures the amounts of heat and work supplied and received, the coefficients of performance of the machine used as a refrigerating machine and as a heat pump.…”

Performance investigation of a novel Franchot engine design

“…Stirling engines running on high temperature differences have a large range of applications and can achieve high power densities and efficiencies . However, so far Stirling engines have not been widely deployed due to a number of remaining challenges: working fluid leakage; large volume and weight; low compression ratio due to the heat exchangers; complexity of the materials needed to manufacture the engine; and total system cost . On the other hand, medium temperature Stirling engines (up to 600 K) can use simpler and cheaper technologies and materials which will reduce the severity of the challenges for high temperature Stirling engines.…”

“…Those heat exchangers increase the dead volume (also called un‐swept volume) of the system, in addition to the dead volume in the regenerator, the cylinder clearance, and the connecting lines. While the dead volume should ideally be zero, in practice dead volumes make up over 50% of the total engine volume with a direct influence on the engine power . Directly heating the expansion cylinder and cooling the compression cylinder instead of using tubular heaters and coolers reduces the total dead volume and pressure drop in the engine.…”

Design of Ericsson Heat Engine with Micro Channel Recuperator

“…Steam turbines are good for large power plants, and Stirling engines are proposed for distributed installations. The Stirling engine in general has high efficiency, long service life, and many other useful properties, but in existing versions it demands high-temperature difference [8] and for this reason demands expensive materials. This leads to elevated cost of this engine.…”