Control system and method for generating power by waste heat of diesel engine

Abstract

The invention provides a control system and method for generating power by waste heat of vehicle diesel engine, wherein the control method comprises the following steps: converting the waste heat which is taken away by the exhaust of a diesel engine to an available power by using an organic rankine cycle with a high-temperature circuit of close-loop feedback control, outputting the available power, converting the waste heat which is taken away by the cold solution of the diesel engine to an available power by using an organic rankine cycle with a low-temperature circuit of close-loop feedback control, outputting the available power and driving the electric generator generate electricity; the flow rate of working medium is controlled by regulating the revolution speed of a motor, and a pressure regulation valve of high-temperature circuit is connected to the working medium of the high-temperature circuit in parallel so as to limit the supreme evaporating pressure and control the flow rate of the cold air which is flown through a condenser and to regulate condensation temperature of the low-temperature circuit. The control system for generating power by waste heat is used for judging the working condition of the engine by collecting the revolution speed of the engine and the position signal of the accelerator pedal, accurately regulating flow rates of the working mediums of high-temperature circuit and low-temperature circuit, fully utilizing the waste heat of diesel engine, improving the thermal efficiency of the diesel engine and simultaneously reducing the harm of exhaust of the diesel engine to the environment.

Description

technical field [0001] The invention belongs to the technical field of waste heat recovery, and relates to a power generation control system and a control method using waste heat of a vehicle diesel engine. The system adopts the coupling method of high-temperature organic Rankine cycle with closed-loop feedback control and low-temperature organic Rankine cycle with closed-loop feedback control, and adjusts the thermodynamic cycles of the high-temperature loop and low-temperature loop through the designed closed-loop control system. Background technique [0002] At present, only about one-third of the heat energy generated by the fuel combustion of vehicle diesel engines is utilized, and as useful work output, nearly two-thirds of the heat energy is dissipated by the exhaust gas of the engine, the cooling system, and the convection and radiation of the engine body. Wasted in vain. If this part of wasted energy can be effectively utilized, on the one hand, it can improve 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 diesel 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 and inefficient, and are not suitable for automotive diesel 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 do not consider the wide range of operating conditions of the vehicle diesel engine and the characteristics of long duration. It is possible to maximize the utilization of diesel engine waste heat at a certain operating point, but it is difficult to achieve it at other operating points

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