Miniaturized integrated system for recovering waste heat of internal combustion engine and control method thereof

Abstract

The invention discloses a miniaturized integrated system for recovering waste heat of an internal combustion engine. The miniaturized integrated system improves fuel economy of the internal combustionengine by using the CO2 power cycle to recover the waste heat of the internal combustion engine, and achieves miniaturized integration by replacing an original radiator, intercooler and EGR cooler ofthe internal combustion engine, and the application of a waste heat recovery system on a whole vehicle is facilitated. By controlling the rotational speed of valves and working medium pumps, only theexhaust waste heat is recovered under the low speed working condition of the internal combustion engine, so that the normal operation of the internal combustion engine is ensured; and in the high speed working condition of the internal combustion engine, working media are connected in parallel in a two-way mode, and branches are separately connected in series to recover the low temperature cylinder liner water waste heat and high temperature exhaust waste heat, the low temperature pressurized air waste heat and the high temperature EGR waste heat to maximize the recovery and utilization of the waste heat of the internal combustion engine without affecting the operation of the internal combustion engine. The output power of a CO2 power cycle expander can be incorporated into the output work or power generation of a crankshaft of the internal combustion engine through mechanical connection to drive vehicle accessories or drive the working medium pumps, so that the fuel economy of the internal combustion engine is improved.

Description

technical field [0001] The invention relates to the field of vehicle heat management, in particular to a miniaturized integrated system for recovering waste heat of an internal combustion engine. Background technique [0002] As the main power equipment of the vehicle, the internal combustion engine is limited by the current technology, and its thermal efficiency is only 30% to 45%, and the remaining energy is dissipated into the atmosphere through the exhaust, cooling system, and lubricating oil system. Among them, except about 5% friction loss, exhaust waste heat energy usually reaches 25%-30% of the total combustion energy, and the temperature can reach 200-600°C. The cylinder jacket water waste heat energy in the cooling system usually reaches 15% of the total combustion energy. %~20%, the temperature is 80~90℃, the exhaust gas recirculation (EGR) waste heat energy usually reaches 5%~8%, the temperature is 200~750℃, the supercharged air waste heat energy usually reaches ...

AI Technical Summary

Problems solved by technology

However, the waste heat recovery system based on the organic Rankine cycle has problems such as large structure, leakage of working fluid, and difficulty in completely recovering waste heat, which have become the main reasons that limit its engineering application.

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