Flat Panel Solar Water Heater Project

working principle
Solar water heaters are heating devices that convert solar energy into heat energy, heating water from low temperature to high temperature to meet the hot water use of people in life and production. According to the structure, solar water heaters are divided into vacuum tube solar water heaters and flat panel solar water heaters, mainly vacuum tube solar water heaters, accounting for 95% of the domestic market share. The vacuum tube type domestic solar water heater is composed of heat collecting tubes, water storage tanks and brackets and other related parts. The conversion of solar energy into heat energy mainly depends on the vacuum heat collecting tube, and the vacuum collecting tube uses the principle of hot water floating on the cold water to make the water generate microcirculation. Get the hot water you need.
The sunlight passes through the first layer of glass of the heat absorbing tube to the black heat absorbing layer of the second layer of glass, and absorbs the heat of the solar energy. Since the two layers of glass are vacuum insulated, the heat transfer is greatly reduced. (radiation heat transfer still exists, but there is no heat conduction and heat convection), most of the heat can only be transferred to the water inside the glass tube, so that the water in the glass tube is heated, and the heated water is lightly moved up the heating surface of the glass tube. Entering the insulated water storage tank, the water with relatively low temperature in the barrel enters the glass tube along the backlight surface of the glass tube to be replenished, so that the water in the heat storage water bucket is continuously heated, thereby achieving the purpose of manufacturing hot water.
Endothermic process
When the vacuum tube type water heater absorbs heat, the solar radiation passes through the outer tube of the vacuum tube, is absorbed by the collector coating film, and is transferred to the water inside the tube along the inner tube wall. After the water in the tube absorbs heat, the temperature rises, the specific gravity decreases and rises, forming an upward power, forming a thermosyphon system. As the hot water continues to move up and is stored in the upper part of the water storage tank, while the lower temperature water is continuously replenished along the other side of the tube, the whole tank water is raised to a certain temperature.
The flat-type water heater is generally a split type water heater. The medium is naturally circulated by the thermosyphon in the heat collecting plate, and the heat of the solar radiation on the heat collecting plate is timely transmitted to the water tank, and the heat exchange (jacket or coil) is adopted in the water tank. Heat is transferred to cold water. The medium can also transfer heat through the pump cycle.
Circulation line
Domestic solar water heaters usually work in a natural circulation with no external power. The vacuum tube solar water heater is a direct insertion structure, and the hot water is powered by gravity. Flat-panel solar water heaters are powered by tap water pressure (called top water). The solar central heating system uses pump circulation. Since the solar water heater has a small heat collection area, in consideration of heat energy loss, pipeline circulation is generally not used.
Use process
The flat-panel solar water heater works in the top water mode, and the vacuum tube solar water heater can also implement the top water working mode, and the water tank can be jacketed or coiled. The advantage of the top water work is that the water supply pressure is the tap water pressure, which is larger than the natural gravity type pressure, especially when the installation height is not high, which is characterized by the fact that the water temperature is high first and then low during use, easy to grasp, and the user is easy to adapt, but requires tap water. Maintain water supply capacity. The solar water heater in the top water working mode is more expensive and higher in price than the gravity water heater.
Temperature difference control collector cycle
In the solar hot water heating system, there is a collector temperature detector and a water temperature sensor. After the heat collecting system absorbs the solar radiation, the temperature of the heat collecting tube rises. When the temperature of the collector and the water temperature of the water tank are Δt, the detection system The command is given, and the circulating pump inputs the cold water in the central water heater into the collector, and the water is heated and then returned to the water tank, so that the water in the water tank reaches the set temperature.
2. Floor heating pipe circulation system
Add a hot water circulation pump to control the floor heating pipe circulation through the controller. When the water temperature reaches the set temperature, the floor heating circulating pump is automatically activated, so that the high temperature water is circulated indoors through the floor heating coil, so that the indoor temperature is continuously increased. When the water temperature of the water tank is lower than a certain set value, the floor heating pump is automatically stopped.
Solar photothermal conversion materials are the most important solar materials. Materials in the field of photothermal utilization can be classified into heat storage materials, heat conductive materials, thermoelectric materials, heat collecting materials, etc.
Heat storage material
The heat storage materials mainly include phase change heat storage materials and sensible heat storage materials. The latent heat storage technology that uses the solid-liquid or solid-solid phase change latent heat of phase change materials to store thermal energy has become the most practical development potential due to its advantages of large heat storage density, approximate isothermal heat storage process, and easy process control. The most widely used and most important way to store heat.
Thermal material
The heat conductive material mainly has a heat conductive flow material and a heat conductive flow pipe material, and the heat storage material can also be used as a heat conductive flow material in a liquid phase or a gas phase state.
Thermoelectric material
Thermoelectric materials (also known as thermoelectric materials) are functional materials that use the motion of internal carriers to achieve direct mutual conversion of thermal energy and electrical energy. The working principle is that solids have different electron or hole excitation characteristics at different temperatures. When there is a temperature difference between the two ends of the thermoelectric material, the difference in the amount of electron or hole excitation at both ends of the material will form a potential difference (voltage). The thermoelectric materials are mainly classified into four types: a semiconductor metal alloy type thermoelectric material, a skutterudite type thermoelectric material, a metal silicide type thermoelectric material, and an oxide type thermoelectric material.
Heat collecting material
The sun mainly brings light and heat to the earth in the form of electromagnetic radiation. The wavelength of solar radiation is mainly distributed in the range of 0.25 to 2.5 μm. In terms of photothermal effect, the infrared band in the solar spectrum directly produces a thermal effect, and most of the light cannot directly generate heat. According to the material of the heat absorbing core, there are steel plate iron, copper, all aluminum, copper and aluminum composite, stainless steel, plastic, lithium bromide, lithium chloride, sodium sulfide, silica gel, water, etc., which is commonly used in the world. Heater and copper-aluminum composite collector.
solar collector
The heat collecting element in the system. Its function is equivalent to the electric heating pipe in the electric water heater. Unlike electric water heaters and gas water heaters, solar collectors use the radiant heat of the sun, so the heating time can only be achieved when the solar radiation reaches a certain value.
Full glass solar vacuum collector tube. The structure is divided into an outer tube and an inner tube, and the outer wall of the inner tube is plated with a selective absorption coating. The collector plate of the flat plate collector is coated with a heat absorbing film such as black chrome, and the metal pipe is welded on the heat collecting plate.
Insulation tank
A container for storing hot water. The hot water collected by the heat collecting tube must be stored in the insulated water tank to prevent heat loss. The capacity of a solar water heater refers to the water capacity that can be used in a water heater, and does not include the capacity that cannot be used in a vacuum tube. For a pressurized solar water heater, its capacity refers to the capacity of the medium in which heat exchange can occur.
The solar water heater insulation tank consists of three parts: the inner tank, the thermal insulation layer and the water tank outer casing.
The tank liner is an important part of storing hot water, and its material strength and corrosion resistance are essential. There are stainless steel, enamel and other materials on the market. The quality of the insulation layer insulation material is directly related to the insulation effect, which is especially important during the cold season. The better insulation method is the polyurethane foaming process. The outer casing is generally a color steel plate, an galvanized sheet or a stainless steel plate.
The insulated water tank requires good insulation effect, corrosion resistance and clean water.
support
A shelf that supports the collector and the insulated water tank. Requires a firm structure, high stability, resistance to wind and snow, aging resistance, and no rust. The material is generally sprayed with stainless steel, aluminum alloy or steel.
Connecting pipe
The solar water heater firstly enters the cold water into the hot water storage tank, and then transfers the heat to the heat preservation water tank through the heat collector. The hot water tank is connected to the indoor cold and hot water pipes, so that the whole system forms a closed loop. A properly designed, properly connected solar line is critical to the ability of the solar system to achieve optimal operation. The solar energy pipeline must be insulated, and the cold area in the north needs to be installed on the outer wall of the pipeline to ensure that the user can use solar hot water in the cold winter.
Control unit
The intelligent solar water heater controlled by mobile phone short message has the functions of water temperature and water level inquiry, fault alarm, starting water supply, shutting off water supply, and starting electric heating, which is convenient for users.
Product Categories
1. From the heat collection section:
1) Glass vacuum tube solar water heater
It can be subdivided into all-glass vacuum tube type, heat pipe vacuum tube type, U-shaped tube vacuum tube type/vacuum tube collecting heat, and heat storage integrated boring type. Commonly used is all-glass vacuum tube type, its advantages: safety, energy saving, environmental protection, and economy. In particular, the solar water heater with auxiliary electric heating function is mainly based on solar energy, and the energy utilization mode supplemented by the electric energy enables the solar water heater to operate normally all the time throughout the year, and the efficiency is still relatively high when the ambient temperature is low. The disadvantage is that the volume is relatively large, the glass tube is fragile, the scale is easily accumulated in the tube, and the pressure cannot be operated.
2) Flat type solar water heater
Flat-panel solar water heaters can be divided into tube plate type, wing tube type, coil type, flat box type, round tube type and heat pipe type. Its advantages: good overall,
It has long life, low failure, low safety hazard, can be operated under pressure, safe and reliable, large area of heat absorption body, easy to combine with building, strong resistance to water and air drying, and its thermal performance is also very stable. The shortcoming is that the non-vacuum inside the cover plate has poor heat preservation performance, so the heat collection performance is poor when the ambient temperature is low, and the relative power consumption is adopted when the auxiliary heating is used. The thermal efficiency is low when the ambient temperature is low or when the outlet water temperature is high.
3) Ceramic hollow flat solar water heater
The ceramic solar panel is a hollow thin-walled flat-box solar collector with a common ceramic as a base and a three-dimensional mesh vanadium-titanium black porcelain as a surface layer. The ceramic solar panel is made of porcelain material. It is impervious to water, impervious to water, high in strength, good in rigidity, non-corrosive, non-aging, non-fading, non-toxic, harmless, non-radioactive, and the absorption rate of sunlight is not attenuated. Photothermal conversion efficiency.
According to the China Solar Water Heater Quality Supervision and Inspection Center, the solar absorption ratio of ceramic solar panels is 0.95, and the daily heat of concrete-structured ceramic solar roofs is 8.6MJ, which is much higher than the Chinese standard. The ceramic solar panel is low in manufacturing cost, low in sunlight absorption ratio, and has the same life span as the building. It can be used to share the structural layer, thermal insulation layer, waterproof layer, simple structure, and better thermal insulation effect than the original roof. The concrete structure ceramic solar roof, the sunny wall surface and the balcony railing surface integrated with the building provide hot water, heating and air conditioning for the building; provide heat energy for industry, agriculture and aquaculture; can be used for large-scale solar hot water power generation and wind in the desert Road power generation, seawater desalination, brackish water desalination, desertification into farmland.
2. Classification from structure:
1) Compact solar water heater: It is to insert the vacuum glass tube directly into the water tank, and use the circulation of heated water to raise the water temperature in the water tank. This is the most common solar water heater in the market.
2) Split type water heater: The split type water heater separates the collector from the water tank, which can greatly increase the capacity of the solar water heater, and does not adopt the falling water working mode, thereby expanding the scope of use.
3. From the pressure of the water tank:
1) Pressure-bearing solar water heaters: The water output of solar water heaters is under pressure. Generally, it is a top-water type work, and it is not necessary to use a pressurized water tank.
2) Non-pressure-bearing solar water heaters: ordinary solar water heaters are non-pressure-bearing water heaters. The water tank has a pipe that communicates with the atmosphere. It uses the height difference between the roof and the home to generate pressure when using water. Its safety, cost and service life are much more significant than the pressure type.
Features
High-tech products, copper-aluminum anodized composite core or full copper core, high surface treatment process, good heat transfer performance, strong heat absorption capacity and large water production.
The system has good heat preservation performance, large heat storage energy, and the water storage function of the heat preservation water tank can meet the needs of large-volume personnel to use hot water centrally, and can also be used as emergency water source when water is stopped.
The solar water heater system is fully automatic and static operation, no need for special care, no noise, no pollution, no leakage, fire, poisoning, etc. It is safe and reliable, environmental protection and energy saving, benefiting the country and the people.
It has a sewage purification function, and the water source is clean and pollution-free.
The vacuum tube solar water heater has good insulation performance and strong anti-freezing ability.
Large-area installation has insulation effect on the floor
Application scenario
Solar water heating engineering solutions are increasingly used in residential areas, villas, hotels, tourist attractions, science parks, hospitals, schools, industrial plants, agricultural planting and breeding areas, etc., for different areas of hot water use Rational design and configuration to achieve comprehensive utilization of energy and reduce cost investment.
solution
The solar water heating project is mainly composed of solar collectors, heat storage systems, control systems, heat exchange systems, auxiliary energy systems, insulation materials, piping systems and accessories. The solar collector absorbs the heat of the sun and heats the water in the pipeline. The heated water is transported to the heat storage device through the pipeline through the circulation pump. The design of the overall energy system can provide basic hot water for the boiler, heat pump, etc. The road is transported to various hot spots for use.
System composition:
solar collector:
1. It is suitable for installation on roof and other fixed installation positions (steel structure brackets, etc.);
2. The collector is beautiful and can be installed at any angle and is easy to maintain;
3. The collector models are various and can meet any space installation, and the customers choose diversified.
Thermal storage system:
1.JDSOLAR patented engineering water tank, strong anti-corrosion performance, reasonable design of nozzle, convenient connection pipe;
2. The insulation layer is formed by polyurethane foaming once, foaming is uniform, and the heat preservation effect is good;
3. The model is complete, which can meet the needs of users with hot water below 80 tons;
4. It can meet the single-family heating demand of buildings below 400 square meters.
Heat exchange system:
1. Select high-efficiency and high-quality heat exchanger, and the heat exchange effect is good;
2. Using a heat exchange system, the system has good water quality;
3. Design an independent heat exchange system to meet the needs of users with a variety of hot water quality, water pressure and water volume.
Control System:
1. It adopts PLC program module control, multi-point control, high precision and stable performance;
2. The control interface is user-friendly, the module is clear, and the operation is convenient.
Auxiliary Energy System:
1. A variety of auxiliary heat sources are available for selection, electric auxiliary, gas-assisted, coal-fired boiler auxiliary, oil-fired boiler auxiliary, and heat pump auxiliary can all be selected according to user characteristics;
2. The system has more heat and less heat loss.
Insulation Materials:
1. Polystyrene foam material is used for good heat preservation and low heat dissipation;
2. Insulation externally applied aluminum foil, beautiful, radiation-proof heat dissipation.
Piping system and accessories:
1. The pipeline is made of standard PVC pipe, which is economical and reasonable;
2. Standard design of accessories, anti-rust and anti-corrosion.
Program characteristics
The hot water effect guarantees: sufficient water supply is available 24 hours a day throughout the year, that is, hot water is on;
Hot water quality assurance: constant pressure, stable water temperature and clean water quality;
System integration design: system overall consideration, with auxiliary heat source, professional software analysis, system efficient and reliable, user-friendly design;
System quality assurance: comprehensive protection for collectors, water tanks, circulation pumps, pipelines, etc., to ensure safe and stable operation of the system for more than 20 years;
System intelligent control: full data display, intelligent control, household measurement, and accurate information.
Routine maintenance
1. When installing a solar water heater, the water pipe may be dusty or oily. When using it for the first time, the tap can be opened to remove debris.
2. The water stored in the solar water heater should be periodically discharged according to the local water quality. The drainage time can be selected when the collector is at a lower temperature in the morning.
3. The surface of the solar water heater shall be periodically wiped according to the amount of dust falling in the area. It can be cleaned by itself when it rains, and the surface of the water heater can be cleaned to obtain higher heat collection efficiency.
4. When hot water is not used for many days in a continuous sunny day, the hot water temperature is very high. When using a solar water heater, please open cold water first, then open hot water to avoid burns.
5. The outlet end of the faucet generally has a filter device. The scale and debris in the water pipe will gather on the net. It should be removed and cleaned regularly, which can increase the flow of water smoothly.
6. In winter, it is very common for the pipeline to be frozen. If it is found that the pipeline is frozen but the pipeline has not been cracked, the temperature will generally be cleared automatically after the temperature rises. You can also blow it with a hair dryer, or use a towel to wrap the water pipe, then slowly pour it with warm water. Do not use fire to bake, tap the pipe or boil it with boiling water, which will burst the pipe. Repeated freezing will easily cause the pipe to freeze and crack, so it is necessary to strengthen the pipe insulation measures.
7. Solar water heaters need to be cleaned, inspected and disinfected every two to three years. Users can also do some disinfection work by themselves. For example, you can buy some chlorine-containing disinfectant and pour it into the water inlet to let it soak. After a period of time, release it again, it can play a certain disinfection effect.
8. The solar water heater needs to clean the inside of the vacuum tube for an average of two to three years to prevent the scale inside the vacuum tube from affecting the heat absorption effect.
9. If the special instrument for solar water heater configuration needs to pay attention to lightning protection, do not take a bath and unplug the electric heating plug when thunder.