Engine exhaust gas waste heat recovery and control system and method based on organic rankine cycle

Abstract

The invention discloses an engine exhaust gas waste heat recovery and control system and method based on organic rankine cycle, and belongs to the field of energy conservation and emission reduction. In the invention, a waste heat recovery system comprises engine cycle, organic rankine cycle, cooling water cycle and lubrication oil cycle which are coupled together; by means of reasonable control, the system can be convenient to start, stable to operate and rapid to stop according to the operation of the engine under different working conditions; in case of a system failure, the system can be emergently braked; and under the condition of no influence on the normal operation of the engine, the optimal performances of the system can be obtained finally, and the utilization ratio of the engine exhaust gas waste heat is improved greatly, thus thermal pollution of the engine exhaust gas to the environment is improved.

Description

technical field [0001] The invention relates to an engine exhaust waste heat recovery control system and method based on an organic Rankine cycle, which is mainly used for recovering engine exhaust waste heat and belongs to the field of energy saving and emission reduction. Background technique [0002] Related studies have shown that the heat equivalent converted into effective work by the engine accounts for 30% to 45% (diesel engine) or 20% to 30% (gasoline engine) of the fuel combustion calorific value. The energy discharged outside the vehicle in the form of waste heat accounts for 55% to 70% (diesel engine) or 70% to 80% (gasoline engine) of the total combustion energy. Only about one-third of the energy emitted by automobile fuel combustion is effectively utilized, and most of the energy loss is dissipated through engine cooling water and high-temperature exhaust heat. The development and application of engine waste heat recovery technology is still in its infancy in...

AI Technical Summary

Problems solved by technology

However, due to the low thermoelectric conversion efficiency, only a small part of the exhaust heat of the engine can be used, and it is necessary to further improve the thermoelectric conversion efficiency and find materials with higher thermoelectric conversion efficiency.

The steam power generation device has advantages in utilizing low-grade heat energy, but the disadvantage of this system is that it is relatively complicated and heavy and has no working medium recovery device

The exhaust gas turbine power generation device has a simple structure and is easy to install, but it will affect the performance of the engine and needs further research

[0004] From the above analysis, it can be seen that a system with reasonable structure, simple operation, obvious waste heat recovery effect and low cost should be used to recover the exhaust heat of the engine, but the research on this aspect is still in the preliminary research stage, and the current models are Does not consider how to reasonably control a complete system, including the working process of engine cycle, organic Rankine cycle, cooling water cycle and lubricating oil cycle

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