Temperature sensing device for a hot gas engine heater head

摘要

An improved hot gas engine heater head where a thermocouple is coaxially positioned in an isolation tube having one closed end and the isolation tube is coaxially positioned in one of a plurality of heater tubes forming a part of a working gas path between two variable volume chambers and traversing a combustion gas flow path. The thermo-couple is in heat-transfer contact with the working gas and is physically isolated from the working and combustion gases. The temperature signal from the thermo-couple is conducted by a conduction wire passing through heat insulating material such that neither the thermo-couple nor the conduction wire is exposed directly to the working gas or the combustion gas.