Abstract: When a flow of a working medium stagnates in an expander or evaporator of a Rankine cycle apparatus including a closed working medium circulation circuit, a high pressure exceeding an allowable maximum pressure level of the expander or evaporator is produced within the closed working medium circulation circuit. In such a case, the water-phase working medium is first discharged via relief valves out of the circulation circuit, so that the pressure within the circulation circuit can be lowered. Then, once vapor within the evaporator, having been lowered in temperature and pressure, flows backward within the closed working medium circulation circuit, the vapor is also discharged via the relief valves out of the circulation circuit. In this way, the pressure within the expander or evaporator can be reliably prevented from exceeding the allowable maximum pressure level.

Abstract: When a flow of a working medium stagnates in an expander or evaporator of a Rankine cycle apparatus including a closed working medium circulation circuit, a high pressure exceeding an allowable maximum pressure level of the expander or evaporator is produced within the closed working medium circulation circuit. In such a case, the water-phase working medium is first discharged via relief valves out of the circulation circuit, so that the pressure within the circulation circuit can be lowered. Then, once vapor within the evaporator, having been lowered in temperature and pressure, flows backward within the closed working medium circulation circuit, the vapor is also discharged via the relief valves out of the circulation circuit. In this way, the pressure within the expander or evaporator can be reliably prevented from exceeding the allowable maximum pressure level.

Abstract: A shaft-like heating member is inserted into and fixed to an oxygen sensing element of a hollowed shaft-like member, together with of a terminal member. A heating portion is located at a portion of the heating member closer to the extreme end thereof. The surface of the heating portion is resiliently pressed on the element inner wall in a side-abutting fashion. In this case, a guide mainly gives rise to the elastic force. With such a side-abutting structure, heat generated in the heating portion is directly transferred to the oxygen sensing element, and heats it. Heat radiated from a portion in the vicinity of its contact position additively heats the oxygen sensing element. Temperature of the oxygen sensor quickly reaches an activation temperature.