CN216808193U

CN216808193U - Solar flash evaporation seawater desalination system based on ultrasonic atomization

Info

Publication number: CN216808193U
Application number: CN202122372074.6U
Authority: CN
Inventors: 季旭; 张海麟; 范全海
Original assignee: Yunnan Normal University
Current assignee: Yunnan Normal University
Priority date: 2021-09-29
Filing date: 2021-09-29
Publication date: 2022-06-24
Anticipated expiration: 2031-09-29

Abstract

The utility model provides a solar energy flash distillation sea water desalination based on ultrasonic atomization comprises collecting system, ultrasonic atomization system, flash distillation system, condensing system. The device comprises a compound paraboloid light-gathering heat collector, a flow control valve, a vortex shedding flowmeter, a thermocouple valve, a flash chamber, a condenser, a vacuum pump, a fresh water collecting tank, a forced circulation pump, a gas-liquid separator and an ultrasonic atomization chamber. The heat conduction oil is heated by the compound parabolic light-focusing heat collector to be used as a driving heat source, the heat exchanger is placed in the sealed flash evaporation chamber, and the seawater in the flash evaporation chamber is heated continuously and circularly. Because the pressure in the flash chamber is lower than the saturated vapor pressure corresponding to the seawater, the ultrasonically atomized seawater is quickly vaporized, flows out of the flash chamber under the drive of air flow, flows into the condenser along the pipeline to be condensed into liquid water, and is collected by the steam-water separator to obtain fresh water. The ultrasonic atomization device has the main advantages that the seawater is atomized into micron-sized liquid drops through ultrasonic atomization, the specific surface area of the atomized seawater is increased, and the yield of fresh water is improved.

Description

Solar flash evaporation seawater desalination system based on ultrasonic atomization

Technical Field

The utility model designs a solar flash evaporation seawater desalination system based on ultrasonic atomization, and belongs to the field of solar seawater desalination.

Background

71% of the earth's surface is covered by water, but 97% of it is high salinity ocean water, and the fresh water resource available for human consumption is only 3%. Most of the world population lives on the coastline, and approximately 70% of the world population lives less than 70 kilometers from the coastline. Therefore, desalination of sea water is a logical method to meet the ever-increasing demand for fresh water. For half a century, seawater desalination technology has kept more than 1 hundred million people in the world, and has promoted the coastal economic and social development in arid desert regions and developed countries. At present, the development of the seawater desalination industry in China still has technical problems. Therefore, the improvement of the utilization rate of the seawater desalination becomes the development direction of the seawater desalination technology. Solar-based seawater desalination systems can be divided into two types: direct collection systems and indirect collection systems.

The seawater desalination device has the advantages that the seawater is desalinated by using a compound parabolic concentrating collector (CPC) and an ultrasonic atomization device, the CPC is a non-imaging concentrating power concentrator, incident light rays in a given receiving angle range can be collected on a receiver according to an ideal concentrating ratio, the continuous sun tracking is not needed during operation, and the seawater desalination device can work only by periodically adjusting the inclination angle for a plurality of times every year according to the size of the receiving angle and the hours of collecting sunlight. Ultrasonic atomization is one of the methods that produces very narrow droplets at atmospheric pressure and ambient temperature, which are ejected at low velocities and micron size distributions. The seawater distillation process removes salt and minerals in seawater as brine.

Disclosure of Invention

A solar flash evaporation seawater desalination system based on ultrasonic atomization applies ultrasonic atomization to flash evaporation seawater desalination and uses CPC for heat supply. The system consists of a heat collecting system, an ultrasonic atomization system, a flash evaporation system and a condensation system. The device comprises a compound parabolic light-gathering heat collector (1), a flow control valve (1) (2), a vortex shedding flowmeter (3), a thermocouple valve (4), a flash evaporation chamber (5), a condenser (6), a flow control valve (2) (7), a cold seawater inlet (8), a vacuum pump (9), a fresh water collecting tank (10), a forced circulation pump (11), a gas-liquid separator (12), a flow control valve (3) (13), a flow control valve (4) (14), an ultrasonic atomization chamber (15), a flow control valve (5) (16) and a circulation pump (17).

The utility model utilizes the light and heat collection principle of CPC. The low-energy flow density solar rays are concentrated to be used for heating a heat transfer working medium, the heat transfer working medium exchanges heat with atomized seawater through a heat exchange coil at the bottom of a flash chamber (5), the pressure in the flash chamber (5) is lower than the saturated vapor pressure corresponding to the seawater, the ultrasonically atomized seawater is quickly vaporized, the seawater flows out of the flash chamber (5) under the drive of air flow, flows into a condenser (6) along a pipeline to be condensed into liquid water, and the liquid water is collected by a steam-water separator (12) to obtain fresh water.

The heat collecting system and the CPC array are obtained by connecting a plurality of groups of tracking-free parabolic condensers, and the CPC only needs to adjust the angle according to seasons in the use process without a complex tracking system.

The ultrasonic atomization system is characterized in that ultrasonic waves are placed in a box body filled with seawater, when the ultrasonic waves normally work, a positive and negative pressure alternating period exists when high-energy ultrasonic waves are transmitted in the seawater, when positive pressure acts, seawater molecules are extruded, the distance between molecules is shortened, and the density is increased; when the negative pressure acts, the seawater molecules are stretched, the molecular distance is gradually increased, and when the negative pressure reaches a certain critical value, the attraction among the seawater molecules is broken, so that local gasification is formed. The specific surface area of the atomized seawater is increased, the heat and mass transfer in the flash chamber is enhanced, the size of the atomized liquid drops reaches the micron level and is uniformly distributed, and the salt scale in the equipment is reduced.

The flash evaporation system controls the flow of the water inlet through the flow control valve, and opens the flow control valve when the temperature is higher than the corresponding saturation temperature in the flash evaporation chamber. The high-temperature seawater exchanges heat with the atomized seawater at the bottom of the flash chamber through the heat exchange coil, the temperature of the seawater is rapidly increased to be changed into vapor, and the vapor flows out of the flash chamber under the drive of air flow.

The condensation system is characterized in that flash steam generated by the condensation system enters a condenser under the suction of a vacuum pump, the latent heat of condensation of the steam is utilized to preheat cold seawater, and a condensed gas-liquid mixture enters a gas-liquid separator to separate liquid.

Compared with the traditional solar seawater desalination system, the utility model effectively improves the solar energy utilization efficiency and the seawater desalination rate by means of ultrasonic atomization, evaporation chamber improvement, CPC and low-pressure utilization and the like.

Drawings

FIG. 1 is a system diagram of the apparatus, as shown in the figure: the system comprises a 1-compound parabolic concentrator collector, 2-flow control valves (1), 3-vortex shedding flowmeters, 4-thermocouple valves, 5-flash chambers, 6-condensers, 7-flow control valves (2), 8-cold seawater 9-vacuum pumps, 10-fresh water collecting tanks, 11-forced circulation pumps, 12-gas-liquid separators, 13-flow control valves (4), 14-flow control valves (5), 15-ultrasonic atomization chambers, 16-flow control valves (5) and 17-circulation pumps

Detailed Description

The utility model provides a solar flash evaporation seawater desalination system based on ultrasonic atomization, and the specific implementation mode of the device is explained in detail below by combining the attached drawings of the specification.

The operation process mainly comprises the following steps (the following steps are carried out simultaneously and are not in sequence):

in the light condensation and heat collection process, in sunny weather with solar radiation, the CPC array is exposed to the sun, the solar rays irradiate the surface of the CPC heat collector (1) and are collected in an internal pipeline for heating a heat transfer working medium, and the temperature is rapidly increased to be more than 100 ℃.

In the flash evaporation process, the heat transfer working medium exchanges heat with the atomized seawater through the heat exchange coil pipe at the bottom of the flash evaporation chamber (5), the temperature of the seawater is rapidly increased to reach boiling and become water vapor, and the pressure in the flash evaporation chamber is lower than the saturated vapor pressure corresponding to the seawater, so the ultrasonically atomized seawater is rapidly vaporized and flows out of the flash evaporation chamber under the drive of air flow.

Ultrasonic atomization process, put ultrasonic wave in the container body (15) equipped with sea water, when the ultrasonic wave works normally, there is positive and negative pressure alternating cycle when the high-energy ultrasonic wave is transmitted in the sea water, when the positive pressure acts on, the sea water molecule is squeezed, the intermolecular distance is shortened, the density is increased; when the negative pressure force acts, the seawater molecules are stretched, the molecular distance is gradually increased, when the negative pressure reaches a certain critical value, the attraction force among the seawater molecules is broken, cavitation bubbles are formed, the specific surface area of the atomized seawater is increased, and the atomized seawater can be rapidly evaporated after entering a flash chamber.

In the condensation process, the condenser (6) is a snake-shaped condenser, steam flows in the pipe, cold seawater flows outside, the cold seawater is preheated by utilizing the latent heat of condensation of the steam, and the condensed gas-liquid mixture enters the gas-liquid separator (12) to separate out the liquid and is gathered to the fresh water collecting tank (10).

Claims

1. A solar flash evaporation seawater desalination system based on ultrasonic atomization is characterized by mainly comprising a heat collection system, an ultrasonic atomization system, a flash evaporation system and a condensation system, and comprising a compound parabolic light-gathering heat collector (1), a flow control valve 1 (2), a vortex street flowmeter (3), a thermocouple valve (4), a flash evaporation chamber (5), a condenser (6), a flow control valve 2 (7), cold seawater (8), a vacuum pump (9), a fresh water collecting tank (10), a forced circulation pump (11), a gas-liquid separator (12), a flow control valve 3 (13), a flow control valve 4 (14), an ultrasonic atomization chamber (15), a flow control valve 5 (16) and a circulation pump (17), wherein a fin coil is arranged in the flash evaporation chamber (5), is placed in the flash evaporation chamber (5), and is connected with the parabolic circulation pump (17) and the compound light-gathering heat collector (1) to form a closed loop, heat conducting oil circularly exchanges heat in the loop to heat seawater in the flash chamber (5), the flash chamber (5) is made of 304 stainless steel, an O-shaped fluorine rubber ring is filled in a gap between the cover plate and the barrel, the air tightness of the O-shaped fluorine rubber ring is guaranteed, high temperature can be borne, the barrel cover and the barrel body are fixed by a flange, the barrel cover is provided with a flow control valve 1 (2) and a vortex flowmeter (3) to control the flow of a water inlet, and extra pumping power is not required to be consumed; in order to adjust and ensure the internal pressure to be stable and ensure safety, a PT100 thermocouple valve (4) is arranged at a water inlet of a flash chamber and is used for monitoring the temperature of the water inlet, when the temperature of the water inlet is higher than the saturation temperature corresponding to the flash chamber, a flow control valve 1 (2) is opened and the flow of the water inlet entering the flash chamber (5) is controlled, the flow of the water inlet is read out through a vortex flow meter (3), an ultrasonic atomization chamber (15) is arranged below the flash chamber (5) and is connected with the flash chamber, seawater is dispersed into liquid drops with smaller particle size after being subjected to ultrasonic atomization and enters the flash chamber, the temperature of the seawater is far higher than the saturation temperature corresponding to the air pressure inside the flash chamber and is rapidly changed into superheated water, the temperature and the pressure of gas-liquid phases inside the flash chamber are in an unbalanced state, the seawater is driven to be rapidly evaporated until the superheat degree is 0, the flash evaporation process is stopped, a vacuum pump (9) is connected with a gas-liquid separator (12) and a condenser (6) in series, the internal pressure of the flash evaporation chamber is adjusted by controlling the power of the vacuum pump (9), the generated flash evaporation steam enters the condenser (6) under the suction of the vacuum pump (9), the condenser is a snake-shaped condenser, the steam flows in the pipe, the cold seawater flows outside, the cold seawater is preheated by utilizing the latent heat of condensation of the steam, the condensed gas-liquid mixture enters the gas-liquid separator (12), and the liquid is separated and converged to the fresh water collecting tank (10).

2. The solar flash evaporation seawater desalination system based on ultrasonic atomization as claimed in claim 1, wherein the compound parabolic concentrator collector heats the heat conducting oil as the driving heat source.

3. The solar flash evaporation seawater desalination system based on ultrasonic atomization as claimed in claim 1, wherein the solar energy is absorbed by a vacuum tube to obtain a high temperature heat source, and a microwave generator is driven by a photovoltaic panel.

4. The solar flash evaporation seawater desalination system based on ultrasonic atomization as claimed in claim 1, wherein the negative pressure can reduce the saturation temperature of seawater, so that seawater can be vaporized into steam under the condition of energy supply of low-grade energy, thereby realizing seawater desalination.

5. The solar flash evaporation seawater desalination system based on ultrasonic atomization as claimed in claim 1, wherein the ultrasonic waves can atomize seawater into micron-sized droplets, and increase the movement rate of water molecules of the droplets, thereby increasing the kinetic energy of the water molecules, so that the seawater can get rid of the constraint of surface tension more easily, the evaporation process is accelerated, and the yield of fresh water is improved.