The biggest problem of desalination is that it is expensive and energy consumption is high. This scheme uses solar thermal heat-collecting technology and solar green energy, which greatly reduces the energy consumption in the desalination process and provides a basis for further reducing desalination costs. For many current desalination technologies, this new slot solar catchment desalination system scheme is mainly aimed at the use of multi-stage flash ingenuation and low temperature multi-effect desalination technology.
In this scheme, the slotted solar heat collection system, which is connected directly to the steamer, reduces the intermediate heat exchange link, can improve the desalination efficiency and greatly reduce the cost.
The steamcondensator is designed as a system with multiple evaporation surfaces and condensation surfaces, the condensation potential heat of the previous level is transmitted to the evaporation surface at the next level, and then pushed to the last level of condensation surface feet, using the condensation potential heat of steam to preheat the sea water into the evaporation chamber so that the condensation potential heat of the steam can be reused. The heat transfer inside the steaming condenser uses the method of forced circulation, improves the heat transfer coefficient, improves the thermal performance of the steaming system, reduces the heat capacity of the sea water to be evaporated in the system, and quickly raises the temperature of the evaporation surface. This steaming system not only makes use of the condensation latent heat of steam many times, but also, because it strengthens its internal heat transfer process, it is relatively high in the temperature of its operation, and therefore the refore has a high water yield.
1,0 Design Foundation.
1.1 The processes and equipment involved in this scheme are able to meet the requirements for the preparation of drinking water for living.
1.1.1 Water production uses: drinking water for living.
1.1.2 System output: m3/d.
1.1.3 System recovery rate:35% to 40%.
1.1.4 System configuration: intake, pretreatment, solar heat ingestion system, condensation unit and related auxiliary equipment.
1.2 The main basis for this programme is as follows: .
1.2.1 Seawater water source: supplied.
1.2.2 Analysis of raw water quality: water quality report.
1.2.3 Design boundaries: from the point of water to the terminal water tank.
1.2.4 Other design fundamentals involved will be discussed and determined in the technical liaison.
1.3 Equipment manufacturing and design reference standards: .
1.3.1 JB2932-86Manufacturing Conditions for Water Treatment Equipment.
1.3.2 HGJ34-90Regulations on Anti-corrosion Design outside the Pipeline of Chemical Equipment.
1.4 Water quality: to achieve the drinking water quality hygiene norms(2001).
1.5 External requirements of the system: .
1.5.1 For cables: depending on the capacity designed for the scheme, the power cableist is delivered to the transformer for distribution.
1.5.2 Outlet water pipe: To the outlet of the terminal water tank.
1.5.3 Drugs: The drugs used in the commissioning process are provided by the user.
1.5.4 Environmental treatment: uniform consideration to standards.
2.0 Process and Description: .
Desalination is the technology of separating salt and water from seawater, although there are many methods of desalination, the scheme uses solar steaming cooling method as the technical route of desalination.
The whole project mainly includes:
(1) The water intake of seawater;
(2) Pretreatment of seawater;
(3)Desalination device;
(4) Plant and supporting works.
2.1 Process.
Sea pumps , sedimentation (clarification) pools, booster pumps, media filters, security filters, high-pressure pumps, solar energy.
Heat collection system and heat exchange system, desalination steaming system, product fresh water pool.
Figure 1-1 Slot Solar Desalination Schematic.
2.2 Process Description.
2.2.1 Pre-processing section .
Seawater water:
According to the coastal environment near the desalination plant, the available site is used in a feasible way of fetching water. The water intake is set up to intercept impurities, the intake is located below 2m below sea level, to ensure the continuous supply of seawater. The water is taken using a DN200 frittolutod pipe, which is secured with a cavity.
2.2.1.1 This design uses the following pre-treatment measures: .
Pretreatment consists of a sedimentation pool, a clarification pool, a dosing system (bactericidal algal ideants, coagulants, reducing agents, scale inhibitors, etc.), and a multi-media filter.
2.2.2 Solar heating system section.
The solar heat collection system is mainly composed of solar collector system, automatic tracking system, circulatory pump and circulation system, temperature control system instrument, etc.
(1)Slot solar collector.
1) The system is aparabolic opening 3 meters, focal length of 1.28 meters, axial total
2) using high-strength high temperature straight-through vacuum tube:2 meters / root, outer diameter 100mm,internaldiameter 40mm.
3)The glazing glass thickness is 5mm,the reflectivity is more than 85%, the mirror back protection paint is three layers of fluorocarbon paint, the bolt edill is fixed to the lens frame body, can resist wind speed of 10 levels.
4)The main beam bracket is type A, and is welded with square steel pipe. Modular design 6 meters a section, stitching easy to install, a variety of combinations.
5)The tracking system uses the self-developed single-axis tracking control system. The electric pushrod selected by the servo mechanism as the drive device is equipped with the crank linkage mechanism to ensure the system tracking accuracy and smooth operation. The tracking accuracy can be up to .1degrees. It can be designed as a remote control method to observe and control the scene through the central control room.
(2)Thermal circulation system.
It is mainly composed of circulating pump, circulation line, filtration system and control system. The system control is automatically controlled by temperature.
2.2.3 Desalination steaming device.
(1) The basic principles and process.
The treated seawater is transported to the heat exchanger through the cold seawater pipe in the condenser, heated to a certain temperature (steam state), introduced to a steaming chamber, and the hot seawater steam is sprayed on the cold seawater circulation pipe wall in the condensing device by spraying the system, which is the required fresh water after rapid condensation;
(2) The steaming chamber cold seawater circulation pipe is made of stainless steel pipe, and the fresh water produced by its condensation flows into the fresh water pool through the fresh water collection pipe.
(3) The hot sea water spray system uses iron or stainless steel pipes, which, after pressure from a high-pressure water pump, spray hot steam onto the wall of the cold seawater pipe. Due to the high temperature sea water caused by the fouling, corrosion phenomenon is serious, so the steel pipe after a period of use, need to be replaced regularly. Its structure is easy to install and remove. It greatly reduces the maintenance and repair work in the process of desalination and reduces the cost of the project.
2.2.4 Product afterwater treatment .
