Diesel engine exhaust waste heat double-effect recovery system

Abstract

The invention disclose a diesel engine exhaust waste heat double-effect recovery system which adopts the technical scheme that a steam turbine is connected with an engine shaft, and the working medium side of an evaporator, the steam turbine, the working medium side of a condenser, a working medium pump and the working medium side of a preheater are sequentially connected to form an organic Rankine cycle thermal power generation system. An exhaust pipe of the engine is connected to the air side of the evaporator through an SCR (Selective Catalytic Reduction) device; a left bypass-valve is connected with a reagent box, and a right bypass-valve is connected with a water tank; and the left and right bypass-valves are connected in parallel and then are connected to a spray nozzle which is connected on the exhaust pipe of the engine. The drained high-temperature water of the circulating cooling water of the engine is connected to a water side inlet of the preheater, and a water side outlet of the preheater is connected to a circulating cooling water inlet of the engine to form a closed cycle. According to the diesel engine exhaust waste heat double-effect recovery system, the limitation of organic ORC(Organic Rankine Cycle) technology(low organic working medium decomposition temperature) on the recovery of diesel engine exhaust waste heat is broken through, the safe and efficient recovery of the exhaust waste heat can be realized, and at the same time, the emission of NOx of the diesel engine can be reduced. Therefore, the diesel engine exhaust waste heat double-effect recovery system achieves the purposes of saving energy and reducing emission.

Description

technical field [0001] The invention belongs to the energy-saving and emission-reduction technology of internal combustion engines, and in particular relates to a diesel engine waste heat recovery device combining an organic Rankine cycle and an exhaust gas selective reduction technology. Background technique [0002] With the increasing shortage of energy and the increasingly severe environmental problems, the energy saving and emission reduction of internal combustion engines has attracted worldwide attention. The use of organic Rankine cycle (ORC) technology to recover waste heat from diesel engines is a current research hotspot, with high thermal efficiency and safety and simple structure. However, the decomposition temperature of the working fluid used in ORC is generally lower than 350°C, while the engine exhaust temperature is generally as high as 500°C to 600°C. Higher temperature may cause the decomposition of organic working fluid, which is one of the key points r...

AI Technical Summary

Problems solved by technology

However, the traditional SCR technology uses very little urea solution to reduce NOx, which cannot significantly reduce the exhaust gas temperature, and is not very helpful to meet the working fluid conditions required for the use of ORC.

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