Recovery system with heat accumulator for internal combustion engine exhausting waste heat and control method

Abstract

The invention provides a recovery system with heat accumulator for internal combustion engine exhausting waste heat and a ontrol method. The internal combustion engine exhausting waste heat is transmitted to organic fluid in an organic rankine cycle by utilizing a conduction oil circuit, and evaporation of the organic fluid is realized; heat from the organic fluid is absorbed or released by utilizing the heat accumulator in series with the organic rankine cycle; enthalpy change in expansion process is converted into useful work output by utilizing an expander; organic fluid flow is adjusted in a small scope according to rotating speed and load of the internal combustion engine; closed loop control of the fluid flow in the heat accumulator circuit is realized according to an overheating temperature of the organic fluid in the outlet of the heat accumulator; closed loop control of the heat conduction oil flow is realized with tail gas temperature in the outlet of the exhaust pipe as feedback; and closed loop control of a fan motor is realized with the organic fluid temperature in the outlet of a condenser as feedback. The waste heat recovery system can fully utilize the engine exhausting waste heat and guaranties that flow change of the organic fluid is not significant when the exhausting waste heat changes in a large scope in a dynamic working process of the engine, thus a small output-power fluctuation amplitude of the expander is guarantied.

Description

Technical field [0001] The invention belongs to the technical field of waste heat recovery and relates to an internal combustion engine exhaust waste heat recovery system and a control method with a regenerator. This system uses a thermal oil circuit to transfer the waste heat in the exhaust of the internal combustion engine to the working fluid in the evaporator of the organic Rankine cycle, and uses a regenerator connected in series in the organic Rankine cycle to absorb or release heat from the organic working fluid. For the organic working fluid, a single-screw expander is used to output useful power to drive the generator to generate electricity. The designed closed-loop control system adjusts the thermal cycle working conditions of the thermal oil circuit, organic Rankine cycle circuit and heat storage circuit according to the working status of the internal combustion engine. Background technique [0002] Only a small part of the heat energy generated by fuel combustio...

AI Technical Summary

Problems solved by technology

Using waste heat for heating can make good use of the waste heat of the engine in winter, but it cannot make full use of the waste heat of the internal combustion engine when heating is not needed in other seasons

The use of temperature difference power generation technology is limited by low conversion efficiency, and it is still not possible to realize practical applications.

Refrigeration devices using adsorption heat pumps are often too bulky, inefficient, and not suitable for automotive internal combustion engine applications

The waste heat recovery technology using the organic Rankine cycle is currently the most efficient. The use of the organic Rankine cycle system is still in the research stage. The current models rarely consider the wide range of operating conditions of the internal combustion engine for vehicles and the duration of the dynamic working process. The characteristics of long and unstable waste heat, can realize the maximum utilization of the waste heat of the internal combustion engine at a certain operating point, but it is difficult to achieve it at other operating points

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