Power generation system using exhausting and cooling waste heat in internal combustion engine at the same time and control method therefor

Abstract

The invention discloses a power generation system using exhausting and cooling waste heat in an internal combustion engine at the same time and a control method therefor. The control method comprises the steps as follows: transferring waste heat in the cooling liquid of the internal combustion engine to an organic working medium by using a preheater in an organic Rankine cycle loop; transferring waste heat taken away by the exhaust gas of the internal combustion engine to the working medium of the organic Rankine cycle loop by using a heat-conducting oil loop; evaporating and gasifying the working medium; transforming enthalpy change in a high-enthalpy expansion process into useful work for outputting by using a single-screw expansion machine; driving a power generator to generate power; taking the tail gas temperature of an exhaust pipe outlet as feedback quantity for realizing the flow closed-loop control of the heat-conducting oil; taking the inlet working medium temperature of the single-screw expansion machine as feedback quantity for realizing the flow closed-loop control of the organic working medium; and taking the outlet working medium temperature of a condenser as feedback quantity for realizing the closed-loop control of the fan motor of the condenser. According to the invention, the flow quantities of the working mediums of the organic Rankine cycle loop and the heat-conducting oil loop are adjusted by using the segmented PI (Proportion Integration) control, so that the waste heat in the internal combustion engine is made the best of, the heat efficiency of the internal combustion engine is improved, and the hazard of the exhaust gas on the environment is reduced.

Description

technical field [0001] The invention belongs to the technical field of waste heat recovery, and relates to an organic Rankine cycle power generation system and a control method for simultaneously utilizing exhaust gas of an internal combustion engine and cooling waste heat. The system uses the preheater in the organic Rankine cycle to transfer the waste heat of the internal combustion engine coolant to the organic working medium, and uses the heat transfer oil circuit to transfer the exhaust heat of the internal combustion engine to the working medium in the evaporator of the organic Rankine cycle. The single-screw expander outputs useful work to drive the generator to generate electricity, and the designed closed-loop control system adjusts the thermal cycle working status of the heat transfer oil circuit and the organic Rankine cycle circuit according to the working status of the internal combustion engine. Background technique [0002] At present, only a small part of the...

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 characteristics of long duration. , the maximum utilization of the waste heat of the internal combustion engine can be realized at a certain operating point, but it is difficult to achieve it at other operating points

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