Waste heat utilization device for internal combustion engine

摘要

A Rankine cycle (6) of a waste heat utilization device includes a circulation path (7) for circulating a working fluid therethrough, an evaporator (12) for causing heat to transfer from cooling water delivered from an internal combustion engine (2) to the working fluid to evaporate the working fluid, a superheater (10) for causing heat to transfer from the cooling water delivered from an exhaust gas heat exchanger (8) to the working fluid delivered from the evaporator to superheat the working fluid, an expander (22) for expanding the working fluid delivered from the superheater to produce driving force, a condenser (24) for condensing the working fluid delivered from the expander, and a pump (28) for feeding the working fluid delivered from the condenser to the evaporator. The evaporator, the superheater, the expander, the condenser and the pump are successively inserted in the working fluid circulation path.

主权项

1. A waste heat utilization device for an internal combustion engine, comprising:
a cooling water circuit including a circulation path configured to circulate cooling water therethrough via the engine, and an exhaust gas heat exchanger inserted in the circulation path configured to cause heat to transfer from exhaust gas discharged from the engine to a part of the cooling water which has been heated while cooling a body of the engine, to additionally heat the cooling water; and a Rankine cycle including a circulation path configured to circulate a working fluid therethrough, an evaporator configured to cause heat to transfer from the cooling water delivered from the engine to the working fluid to evaporate the working fluid, a superheater configured to cause heat to transfer from the cooling water delivered from the exhaust gas heat exchanger to the working fluid delivered from the evaporator to superheat the working fluid, an expander configured to expand the working fluid delivered from the superheater to produce driving force, a condenser configured to condense the working fluid delivered from the expander, and a pump configured to feed the working fluid delivered from the condenser to the evaporator, wherein the evaporator, the superheater, the expander, the condenser and the pump are successively arranged in the working fluid circulation path, wherein: the cooling water circuit further includes flow rate control means for causing the cooling water delivered from the engine to directly flow into the evaporator while bypassing the exhaust gas heat exchanger and the superheater, to regulate a flow rate of the cooling water flowing into the exhaust gas heat exchanger; and a temperature sensor configured to detect cooling water temperature at an outlet of the exhaust gas heat exchanger, and the flow rate control means regulates the flow rate of the cooling water flowing into the exhaust gas heat exchanger in accordance with the cooling water temperature detected by the temperature sensor, to cause heat transfer from the exhaust gas to the cooling water so that the cooling water may boil.