Method and device for generating electricity and preparing fresh water using low-temperature heat source

Abstract

The invention discloses a method and equipment for generating electricity and preparing fresh water by use of a low-temperature heat source. The equipment consists of a seawater pump, a heater, a flash evaporator, a superheater, a mixing chamber, an ascending pipe, a chimney, an air condenser, a water tank, a vacuum pump, a descending pipe, a water turbine generator set, a fresh water pool, a hydraulic ram and an atomization nozzle. In the invention, the seawater is subjected to the steps of heating, flash evaporation, superheating and the like to form low-pressure superheated steam; the superheated steam contacts in the mixing chamber, carries fogdrop, enters the ascending pipe and flows into the air condenser at the top of the chimney to be cooled into condensed water; the condensed water enters the water tank and flows downward through the descending pipe to flush the water turbine generator set to do work and generate electricity and then is stored in the fresh water pool; part of the fresh water is conveyed to the atomization nozzle by the hydraulic ram to be sprayed into the mixing chamber. The equipment disclosed by the invention can make full use of the low-temperature heat source to generate electricity, has the characteristics of high conversion efficiency, high net output power, low generating cost, abundant production of byproduct freshwater and the like, and can be widely applied to the technical field of low-temperature heat source utilization.

Description

technical field [0001] The invention belongs to the technical field of utilization of low-temperature heat sources, and in particular relates to a method and equipment for generating electricity and preparing fresh water by utilizing low-temperature heat sources. Background technique [0002] Low-temperature heat sources include air heat energy, soil heat energy, industrial waste heat, geothermal energy, solar energy, ocean temperature difference energy, etc. Exploring new technologies for the utilization of low-temperature heat sources is a long-awaited and urgently needed issue for scholars from all over the world. At present, the practical method of converting low-temperature heat energy into mechanical energy or electrical energy is still to achieve this conversion through a thermodynamic cycle, generally using a steam power cycle, mainly a Rankine cycle that works in the saturated steam region. The realization of the Rankine cycle can be divided into an open cycle using...

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Problems solved by technology

The advantage of this cycle is that the bulky steam turbine is replaced by a small water turbine, and the bulky surface condenser is replaced by direct spray condensation, so that the cost of power generation is expected to be reduced, but this cycle also cannot by-produce fresh water

At present, there are mainly the following problems in this cycle: First, if the flash temperature of saturated steam is low, the enthalpy drop of the steam will be small and the lifting height will be low; This fundamentally restricts the output power of the cycle; second, the efficiency of transferring the kinetic energy of the steam to the droplets by the friction between the two phases is very low; third, the saturated steam is easy to condense on the tube wall and cause precipitation , so that the flow lifting ratio is reduced, the lifting height is reduced, and the output power is reduced; Fourth, the hot water pump and the cooling water pump consume a lot of power. According to theoretical analysis, only when the actual lifting height is greater than 80m can there be net power output.

Due to the influence of the above factors, the current highest effective lifting height of the droplet lifting cycle is only 21m, which was obtained through experiments by the Guangzhou Institute of Energy Research, Chinese Academy of Sciences, so this cycle still has no prospect of practical application

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