System and method for recycling waste heat of bath sewage by utilizing absorption heat pump

Abstract

The invention discloses a system and a method for recycling waste heat of bath sewage by utilizing an absorption heat pump. The system comprises a hot water storage tank, a cesspool, a tap-water pipe and an absorption heat pump set, wherein the tap water is divided into two branches after being pressurized by a feed water pump; one branch exchanges heat in the absorption heat pump set firstly and then enters the hot water storage tank; the other branch enters a tap-water preheater and exchanges heat with the sewage directly; the effluent absorbs heat and rises the temperature through an absorber and a condenser and then enters the hot water storage tank for being used as hot water for bath; the bath sewage is collected by the cesspool and is purified; the purified sewage is filtered by a filter, is pressurized by a sewage pump, then enters the tap-water preheater, and exchanges heat with the tap water firstly; and the effluent exchanges heat with refrigerating fluid of an evaporator and then is exhausted. The invention does not need to additionally install a boiler as a heat source; and the tap water exchanges heat with the bath sewage directly, so the heat exchange efficiency is improved.

Description

technical field [0001] The invention belongs to the technical field of energy, and relates to a system for recovering heat in sewage, in particular to a system for recovering waste heat from bathing sewage by using an absorption heat pump, and also relates to a method for recovering waste heat in bathing sewage by using the system. Background technique [0002] At present, most public baths such as schools, military camps, swimming pools and bathing centers rely on regularly operated coal-fired boilers to provide hot water. In addition, there are also oil-fired (gas) boilers or electric boilers. However, coal-fired boilers have low efficiency and serious environmental pollution. Oil (gas) boilers are greatly affected by fuel supply and price fluctuations, and the cost is high. Electric boilers that use high-grade electric energy to produce hot water are a kind of energy quality. waste. [0003] The above-mentioned public baths use relatively concentrated heat and discharge ...

AI Technical Summary

Problems solved by technology

Such as the patent "energy storage type heat pump hot water boiler water supply device" (patent number ZL01244858.3, publication number CN2502177, publication date 2002.07.24), the patent "a public bath waste heat recovery heat pump bathing machine" (patent number ZL200610112860. X, Publication No. CN1916510, Publication Date 2007.02.21) and the patent "A Low-Grade Waste Heat Recovery Heat Pump Hot Water Device" (Patent No. ZL200720003768.X, Publication No. The working principle and method of bathroom wastewater heat. Although these methods can effectively recover part of the heat in bathroom wastewater, the driving force of the heat pump is high-grade electric energy. Long-term use will cause waste of energy quality and is not economical. ; Patent Application "A Waste Heat Recovery Type Bathroom Hot Water Boiler Device" (Application No. 200910131279.6, Publication No. CN101520208, Publication Date 2009.09.02) discloses a device that uses a boiler as a heat source to drive an absorption heat pump to recover waste heat, but the The device has the following problems: 1) The driving force of the absorption heat pump comes from the hot water or steam generated by the boiler, and the system requires an additional boiler as a heat source; 2) The tap water does not directly exchange heat with the bathing sewage, but with the intermediate water ring The heat exchange of hot water in the water reduces the heat exchange temperature difference, and the heat exchange efficiency is low. The outlet temperature of tap water is lower than the temperature of direct heat exchange with sewage, which leads to an increase in the capacity of the absorption machine when recovering the same amount of heat.

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