Anti-corrosion and anti-ash-deposition low-grade waste heat cascade recycling system

Abstract

The invention discloses an anti-corrosion and anti-ash-deposition low-grade waste heat cascade recycling system, and belongs to the technical field of heat recovery. The anti-corrosion and anti-ash-deposition low-grade waste heat cascade recycling system comprises a first-stage evaporator, a second-stage evaporator, a heat flow pipeline, an ejector, an expansion machine, a generator, a condenser, a circulating pump and a working medium, and the first-stage evaporator communicates with the second-stage evaporator through the heat flow pipeline. The ejector is connected with the first-stage evaporator and the second-stage evaporator, the expansion machine is driven by the generator and connected with the ejector, the expansion machine is connected with the condenser, the condenser is connected with the second-stage evaporator, and an expansion valve is arranged between the expansion machine and the condenser. Through the action of the expansion valve, the evaporation pressure of a working medium in the second-stage evaporator is reduced, so that the working medium absorbs heat and vaporizes at a lower temperature, heat flow waste heat close to or below an acid dew point can be recycled, and the recycling amount of the waste heat is increased; and secondly, a coupling working mechanism of a primary loop and a secondary loop adopts a gradient utilization mode, so that the utilization rate of waste heat resources is increased.

Description

technical field [0001] The invention relates to the technical field of heat recovery, in particular to an anti-corrosion and anti-dust low-grade waste heat cascade recycling system. Background technique [0002] In actual production and life, there is a large amount of low-grade waste heat, such as a large amount of process cooling water generated in the process of process production, exhaust waste heat above 150°C, etc. Most of these heat will be discharged in vain and cause resources waste. [0003] At present, there are many ways to recover and utilize waste heat. Waste heat recovery can be divided into passive waste heat recovery and active waste heat recovery. Through heat exchangers, industrial wastewater, industrial waste gas and low-temperature fluid are exchanged to recover waste heat, which belongs to passive type. waste heat recovery. Passive waste heat recovery generally does not consume power, but the recovery temperature is limited by the waste heat temperatu...

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Problems solved by technology

[0006] The purpose of the present invention is to provide an anti-corrosion and anti-fouling low-grade waste heat cascade recycling system to solve the problem that when the waste heat temperature is too low in the background technology mentioned above, the heating surface of the heat exchanger operates below the acid dew point and close to the water dew point. The dew condensation on the heat flow side is serious, and a large amount of cohesive dust is formed; not only the serious blockage of the tube bundle of the heat exchange equipment, but also the acid dew medium and dust mixture also cause strong corrosion and abrasion to the heat exchange equipment

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