Solar Water Heater and Solar Energy Information

Solar water heater refers to the solar energy to heat the water heaters. With the gas water heater, electric water heaters in parallel one of the three water heaters. Solar water heaters to solar energy into heat, from low-temperature water heated to high temperatures, to meet people in life, the production of hot water use. Solar water heater is by the collection heat pipe, the water tank and the related appendix is composed, to rely mainly on solar energy conversion into heat collector tube.

Solar Water Heater Works

First, Endothermic process

Solar radiation through the glass cover, is absorbed by collector plate and the wall along the finned tube is passed to the heat absorption of water. Heat-absorbing heat-absorbing water tube after the temperature increases, reducing the proportion of the rise in the formation of a power up to form a thermal siphon system. As the water continues to move up and stored in the tank top, while constantly replenished through the circulation pipe under the water cooler, so the cycle, and ultimately all the water FCL increased to a certain temperature. Existing flat collector, basically using multi-barrel with a good combination of methods, such as rolling or pressing methods, which take the water pipes and the thermal resistance between the heat-absorbing plate is almost negligible. Flat plate solar collector of the core performance of the main factors, one structural design, the second is the surface absorption coating.

Well-designed collector’s board core fin efficiency should be 93%. Collector fin efficiency and the board core board core structure, surface treatment and the overall structure of the collector. The overall structure of the collector can be used to describe the overall heat transfer coefficient, and its influence and its geometric dimensions (fin thickness, material) are the same. In other words, efficiency in the same circumstances, hours of collector plate core heat loss can be thinner. Selective absorption surface to increase the thermal efficiency, but market these products to improve economic efficiency, is often thin fin. Occasions for the water heater when the effect of such products and selectivity actual collector some (not even optional), but fins thicker collector will not be much difference.

Second, Circulation line

Solar water heaters usually work the way the natural cycle, no external power, well-designed system, as long as there is more than 5 ~ 6 ℃ temperature can cycle very well. Water circulation pipe diameter and pipe distribution directly affect the rationality of the heat exchange efficiency of the collector. The majority of cases domestic water heater system, natural circulation flow in the pipeline could as laminar flow. Collector resistance of the piping system along the main resistance came from, much less the impact of local resistance, which branch off than the resistance along the way charge is much greater. When the water temperature increases, due to the kinematic viscosity decreases, the resistance along the smaller, local resistance are larger. In a certain range, as head of diameter is constant, increasing branch diameter is not only the resistance decreased rapidly along the way and reduce local resistance will follow. In general, the hydraulic radius of the branch should be 10mm or more. When the diameter reaches a certain value charge, an increase in charge diameter on the reduced system resistance has little significance.

Third, The process of using top-water type

Solar Water Heater way into water into water type and top-water type. Fell into the water not tap water use affected the course of its shortcomings is the use of low temperature high after the first master the bad words likely to cause sudden embarrassment of water shortage. Is the temperature of the water way to the top of the first high to low, easy to grasp, easy to adapt to the user, but requires water to maintain water supply capacity. Guaranteed in the case of tap water is recommended to use the top of the water way. Domestic solar water heater designed to the top of the water mode, the structure inside the water tank must be reasonably designed to ensure the water evenly and avoid the formation of water “short” or dead. Designed using the pipe can be converted into the best type of connection drowning in the water deficiency or water stress during emergency use.

Solar Water Heater – Material Composition and Manufacturing

Solar water heater is a vacuum tube, tank insulation, support, connecting pipes and other components.

Solar Collector

The collector system components. Its function is equivalent to the water heater in the heater. And electric water heaters, gas water heater is different is that solar collector use the sun’s heat radiation, therefore the heating time only when there is sun.

The current popularity of the Chinese market is all-glass vacuum tube solar collectors. Structure is divided into the outer tube, inner tube, selective absorbing coating, Getter, stainless steel clamp, vacuum laminated and other parts. Mature collector of foreign collectors are flat, flat-plate collector with a long life, high stability, the advantages of recycling, but slightly higher than the cost of the vacuum tube collectors, many of the domestic production of low-cost flat collector performance does not, therefore distorting domestic mainstream manufacturers of solar flat plate collector performance. But the flat-plate collector unstoppable in the solar industry, not misled by some manufacturers to be strangled. Now many designers Design Institute has been aware of the drainage problem.

All-glass vacuum tube solar collectors is usually a high borosilicate glass 3.3 special hardware, the use of selective sputtering vacuum coating process. Nitrogen can be divided into single target coating process of aluminum and copper, aluminum, stainless steel three-target coating process.

Tank Insulation

Hot water storage containers. As solar water heaters only work during the day, but people generally only use hot water at night, so must the collector through the holding tanks of hot water during the day and store the output. Volume of hot water every night combined.

Solar water heater tank insulation from the tank, insulation, water tank shell of three parts.

Holding tank requires effective insulation, corrosion-resistant, water clean, the service life of up to 20 years.

Support

Collector support rack and tank insulation. Requires solid structure, anti-wind, anti-aging, does not rust. Material is usually steel or aluminum color. Required service life of up to 20 years.

Connecting Pipes

The hot water from solar collector heat transfer to the water tank, cold water From the holding tanks will be delivered to the collector pipe, so that the entire system to form a closed loop. Designed, properly connected to the solar loop piping system is essential to achieve optimal working condition. Thermal insulation of hot water pipes must be done. Pipe must conform to standards, ensure that there are more than 10 years of life.

Advantages and Disadvantages of Solar Water Heater

Advantages: safety, energy conservation, environmental protection, the economy. Particularly solar water heaters with auxiliary heating function, it is solar based, energy, supplemented by the energy use, the solar water heater can be used around the clock throughout the year.

Disadvantages: Installation complicated, such as improper installation, will affect the housing, the appearance, quality and the city’s face of the city; maintenance more troublesome, because solar water heaters installed outdoors, the majority in the roof, the roof, so compared to electric water heaters and gas water heaters More difficult to maintain.

The solar-powered water heater is in a solar energy achievement application big industry. It is environmental protection, safety, energy, health, etc., quickly won the favor of consumers, China, is an energy consuming countries, the national annual energy consumption of the total world energy consumption accounts for about 1 / 3, while the country’s total energy Consumption, 1 / 3 is from the building energy consumption. “to the roof to the energy, ” solar water heater is the absorption of solar radiation energy, heating water available to people in life saving equipment used in production.

Performance Advantage

With the continued strengthening of environmental awareness, more and more consumers opt for solar water heaters, but many people on the use of this product are not very understanding. Here, we will be solar water heaters, electric water heaters and gas water heaters to make a rough comparison of the performance.

First, Aspects of water production

Gas water heater 5 liters, 7 liters, 8 different models of promotion, is within 1 minute when the water temperature 25 ℃ hot water production, if the water temperature is 25 ℃, 50 per minute can be produced ℃ hot water 5 liters 7 liters or 8 liters.

Marked water heater is 30 liters, 60 liters, 90 liters, etc., which refers to the capacity of the water heater water, the equivalent of our electric stove add a kettle, the kettle of water Sheng 30 liters, 60 liters 90 liters. Take an 8-liter 40 liters of gas water heater with an electric water heater compared to 8 liters of gas water heater can be produced continuously 8 liters of water per minute, while the water heater need to heat a can of water for half an hour intervals. If the tank water runs out, we have to wait half an hour.

The annual average temperature of solar water heaters in accordance with 15.7 ℃, 2014 hours of sunshine, solar radiation average is 111.59 total kcal / square meter, if the collector area of 2 square meters, the absorption of solar radiation energy is 9.37 × 106 kJ, 35 ℃ according to the calculation of water temperature (based on water temperature 10 ℃), a full year to provide domestic hot water (45 ℃) 53.5 tons per person per bath with hot water about 50 kg, the full year wash 1070 times, 2.93 times the average daily washing.

Second, The heating speed

The current production of gas water heaters are mostly water heater, no matter when, just want to use hot water, open the gas valve and faucets, hot water will flow out. The pre-power electric water heater needs about half an hour to get started. Solar water heater used in fine weather better and the best floor in the six to eight levels.

Third, Temperature stability

As is the rapid heating gas water heater, and adjust the temperature device, as long as the use of the body transferred to the beginning of the temperature comfortable, and then will remain constant at this temperature to supply hot water.

Require the use of electric water heaters also take a cold water pipe is blended with cold water, continue to flow when the tank water, cold water being added, the temperature will gradually decrease until all cold water. So when in use, you need to constantly adjust the proportion of hot and cold water.

Solar water heater is not yet large easy to use, to Sheung Shui, and can not guarantee to always have hot water.

IV, Power aspects

Gas water heater’s power is much larger than the electric water heater, take an 8 liters and 40 liters of gas water heaters, electric water heater compared to 8 liters of gas water heater power is equivalent to 16-17 kW, and 40 liters of the water heater is generally 3 kW This is also why the gas water heater can cause a continuous supply of hot water. So, whether the water heater can be made into 16 kilowatts of it? It is not possible, because household meters, wires can not afford.

V, Price

8 liters of gas heaters generally cost 800 yuan or more, plus installation fee, about more than 1,000 yuan, or even close to 2,000 yuan. Electric water heaters are now more than 500 yuan, plus installation costs, generally less than 1,000 yuan. The price of solar water heaters are more than 3,000 yuan.

Use of the cost, the current is 1.7 yuan per cu m of natural gas per unit of electricity is 0.44 Yuan, while the solar water heaters, water charges only.

VI, In terms of security

Gas water heater has the advantage of fast heating, water volume and temperature stability, and guitar scale small, small footprint, not water control. The disadvantage is used to emit a lot of emissions, emissions of carbon dioxide in addition, there are carbon monoxide, if you are using to close doors and windows, ventilation, carbon monoxide will increase, and in severe cases of poisoning incidents, but if understand this correctly, the use of when the note is also very safe; In addition, high pressure gas water heater starts, and some live in high-level users who do not install booster pump can not start; installation is not convenient, holes in walls, etc. An exhaust fan.

Advantage of the water heater can adapt to all weather changes, the average family can be installed directly used for a long time can be a large flow of hot water power; use does not produce emissions, so this sense is both safe and health, currently on the market Most of the water heater also comes with electric shock devices. The disadvantage is bulky, take up interior space, easy guitar scale, large waste of energy, the latest type of electric water heaters built magnesium anode rod cleaning device, the product is easy to solve scaling problems, but magnesium anode rod to be two years replace one, to the maintenance of trouble.

Advantages of solar water heaters are safe, energy saving, environmental protection, economy, particularly solar water heaters with auxiliary heating function, it is solar based, energy, supplemented by the energy use, can be used around the clock throughout the year. Defects is to install complex, improper installation, will affect the appearance of housing, quality, and the city’s face of the city; because they have to be installed outdoors, maintenance is troublesome.

Solar Water Heater Technological Development

China Solar Energy dating back to 1958, Tianjin university has 12.6 square meters of solar bathroom. By 1973 the world energy crisis, the search for renewable energy, China in the late 70s of last century, the increased R & D and production of solar collectors. Some units before and after 1979, head of R & D all-glass vacuum tube collector. Tsinghua University, the physical background of the use of power vacuum, stuck with it. Cattle is an elongated structure, but there is a layer including glass selectively absorbing coating.

Tsinghua University patent is Al – N / Al solar selective absorbing coating, in the world by creating a single aluminum cathode magnetron sputtering lower infrared low emissivity of aluminum – aluminum nitride ceramic film to absorb sunlight and dilute three parts Aluminum antireflective coatings. Vacuum tube collector can be used in the cold weather, use of low solar radiation, it is suitable for a variety of climate. This is a selective absorbing coating structure, each absorbing layer is only 10-30 nm, low emissivity layer is 150 nm.

The development of solar thermal industry. In the solar selective absorbing coating breakthrough core technology, production and research through the combination of good performance and low cost of media production.

2001 to 2006, the rapid development of solar energy heat utilization industry. 2006 sales of nearly 300 million to provide employment opportunities for more than 60 million. China solar water heater installed capacity in 2005 77% of the world. Vacuum-type accounts for about 90% of world production, annual production of about 3.3 borosilicate glass, 70% of the world, Getter about 95% of the world, was about 190 million vacuum tubes, was about 090 million tubes use. A large number of tubes are manufactured in China are Chinese-getter. These three aspects we have to go ahead. Supporting the formation of the industrial chain. 30 million tons of which 3.3 glass vacuum tubes for 28 million tons. 1000 vacuum tube coating production lines and supporting equipment, production capacity is 200 million, the assembly of about 20 million square meters of solar water heaters, as well as ancillary equipment. Some of the technological transformation of key enterprises do to improve the enterprise’s equipment level and conditions.

Solar water heater market analysis

Tensions in the global energy situation, global warming a serious threat to economic development and health of people living today, countries around the world are looking for new alternative energy strategies, in order to achieve sustainable development and the development in the future to obtain a superior position. Solar energy for its clean, steady flow, security and other significant advantages, as focus of attention. In the solar industry, solar thermal water heater is undoubtedly the most mature conversion technology, and its industrialization process are more solar photovoltaic(PV), solar power and other industries one step ahead. But the market has yet to be standardized, consumers have yet to be nurtured, technologies have yet to improve, and thus for the enterprise there is a large room for growth.

China’s solar thermal technology research and development began in the late 20th century, 70, and its focused on simple, inexpensive low-temperature heat utilization of appropriate technology, such as solar greenhouse, solar, passive solar house, solar water heaters, and solar dryers . Such technologies used widely in rural areas, to alleviate the energy shortage in rural areas, improving the rural ecological environment and farmers played a positive role in life, and received results. 80 solar water heaters, the 20th century, included in the national “Plan” and “July” science and technology research projects. The main R & D project is the efficient flat panel solar collector and all-glass vacuum tube. In the 90′s all-glass vacuum tube of the scientific and technological achievements into productive forces through the trial – to design and supporting the formation of tube production line is the most outstanding scientific and technological achievements.

2007, China solar water heater production growth rate of about 30%, annual production of 23.4 million square meters (16380MWth), the total reserves is about 108 million square meters (75600MWth) (solar water heater life expectancy by 10 years of computing, 1997 years ago to maintain amount set aside). In 2007, the solar water heater market sales of about 32 billion yuan, output value of enterprises with more than billion yuan more than 20; 2007, solar water heater is about 28% growth in exports, 6,500 million dollars, exports to Europe, America, Africa, Southeast Asia more than 50 countries and regions.

China’s annual production capacity of solar water heater 2 times in Europe, North America 4 times, has become the world’s largest producer and largest solar water heater solar water heater market, and is still 20% -30% annual rate of increase. But the Chinese manufacturer of solar water heaters more than 5,000, in addition to Lok Sang, Wong Ming, Qinghua Sun, Hua Yang, Sun Yu, Li Norit in 10 national brands for quality, excellent service and high market visibility, the industry, there are many diverse and caught up in brand-name companies, this situation is not conducive to long-term development of the industry, which requires government departments to regulate and strengthen regulatory guidance. Despite the market situation is not satisfactory, but the market outlook remains good. With the national economy and improve people’s living standards, the residents of the home indoor growing demand for hot water, solar water heater market has great potential in China.

Solar Water Heaters Use Common Sense

Daily use common sense

Q: Solar water heaters in the course of what issues should pay attention to?

A: 1、Note Sheung Shui time. 2、According to weather conditions, the decision on the water to ensure proper water bath. 3、Regularly check the water heater pipes, vents and other components are working properly. 4、Air pollution is serious, or wind, wash vacuum dry areas on a regular basis. 5、Water heater installation, the non-professionals do not easily move, loading and unloading machine, to avoid damage to critical components.

Q: How to determine whether the water is full of solar water heater?

A: An ordinary solar water heaters have an overflow pipe, according to the overflow pipe to determine whether the drainage of water over the state, the other can be equipped with water level control device, water full automatic alarm, according to police discrimination.

Q: The best time for solar water heaters, Sheung Shui, what time?

A: Water vacuum tube, that air drying conditions, the tube can reach temperatures of about 250 ℃, at this time caused by the vacuum tube burst, Sheung Shui, it is in the tank or the first time, Sheung Shui, water must be before sunrise or sunset in the half-hour After.

Q: Solar water heaters will not cause harm? Use of solar water heaters, which area should pay attention to safety?

A: Use of solar water heaters used to pay attention to security: First, to prevent users from burns, nearly two years, there have been several cases of patients with burns, burns often think of solar hot water temperature will not produce too high, in fact, solar water heater in the summer The temperature often reaches above 80 ℃, users often pay no attention to burn, turn on the water bath in the first release to be noticed at first was part of the water stored in cold water, once the water flow to the solar water heater, the temperature suddenly rises to 80 ℃ above, resulting in burns; second is to tighten the water heater to prevent entry of typhoon blew it from the room, causing damage.

Q: Solar water heaters for a long time without water, will heat bad?

A: Vacuum tube solar water heaters, high efficiency, in the case of sunny summer, the water temperature up to boiling point less than two days, if a long time without water, such as travel, tourism, make the tank a long time in high temperature and pressure of the state, will promote the seal Circle of aging, accelerated aging of polyurethane, atrophy, and sometimes the exhaust does not flow, too much pressure will make a bad expansion tank, but also guitar scale, shorten tank life. Therefore, if you are not at home long term, should arrange for someone else often heat water in cold water, or place in the vacuum tube collector covering block the sun, to be home, and then removed.

Q: Several days of solar water heaters can not use hot water bath?

A: Several days of solar water heaters are generally not used in hot water, water, reach above 70 ℃, especially in the summer, sunny weather more than 2 days, water will boil, to cool down properly at night, so the water temperature maintained at 60 ℃ -70 ℃ area very long time, and this temperature region is an excellent bacteria in water temperature, so long as several days or without hot water, poor water quality, bacteria and more, to be discharged out, do not take a bath or to boil water Drinking, so that the water bath on skin adverse long-term use can cause skin diseases such water for bathing.

Q: Why is frequent use of solar water heater good?

A: Solar water heaters in use, should always use the best day is recommended to use 4 to 5 times in 4 hours time interval, it is because:

① Long water users on the lower floors, the water is actually used in the low-temperature water pipe (solar water heater inside the water stays cool in the pipe to form); especially in the northern winter, the outside temperature is low, Sometimes reach -25 ℃ below the upper and lower water pipeline to the water cooler soon, if the six floors, each time a user need to let go of the first floor of a basin of cold water, especially waste, if you like a number of frequently used; ②Effectively freezing, so there is always heat up and down water pipeline, together with insulation layer, which can effectively freeze. In the northern winter, many people also use the indoor water heater valve slightly open, dripping down the way to frost.

Q: Solar water off in winter should it?

A: No, the water tank by the heat capacity, meaning that the solar water tank there is some heat, the greater the amount of water, heat capacity, the more to slow the rate of ice. If you put the water, the water in the tube is not put out, the heat capacity is smaller, easier to freeze.

Q: How to use solar water heaters in winter?

A: Low intensity of sunshine, sunshine time is short, and the solar energy environmental temperature is low, it may not reach the expected day, the day temperature, Sheung Shui, this time inside the water tank can be properly controlled, or if necessary, start the electric auxiliary systems, or gas auxiliary systems.