Solar water heater
Now there are many options for installing water pipes, such as PPR water pipes, copper pipes, copper-plastic pipes ( aluminum-plastic pipes), PVC pipes, iron pipes, etc. .
In fact, considering various factors, PPR water pipes are quite ideal. The reason is also very simple. Firstly, the quality of good PPR water pipes is very reliable, which is quite comparable to that of copper pipes. Secondly, the price is more acceptable and much lower than copper pipes; that it is healthy, without any rust or patina.
Note that the water pipe must be rated 6 points. PPR water pipes are divided into cold water pipes and hot water pipes. The key is the thickness of the pipe wall. It is recommended that everyone use hot water pipes for drainage at home. the priceis not much more expensive.
Considering that solar water pipes must be antifreeze, meaning they cannot freeze and crack under normal circumstances, there are only three types of pipes on the market: true PEX reticulated pipes, PERT pipes. , and PB pipes.
At present, most of the market uses PEX as solar water pipes, because it is frost-resistant and its price is relatively low. However, over the past couple of years, many manufacturers have reduced their crosslinking. degree a lot in order to compete for the market, so The cost is reduced, but its antifreeze performance is also greatly reduced. If you use it, it is recommended not to choose one with less than 140 yuan. -the freezing performance of PERT is better than that of PEX, but its cost is relatively higher, so it is now very popular in the market. It is rarelyt used for solar energy and PB pipes should be considered the best antifreeze; on the market. They are now used in many high-end underfloor heating projects. Of course, their costs are higher and they cannot be promoted in the solar energy sector at present.
Therefore, it is recommended to choose higher quality PEX cross-linked pipes, as long as you are not trying to be cheap.
PPR cannot be used as solar water supply and drainage pipes. It can freeze and crack in one winter in the north (it can be used in the south). it does not work.
Aluminum-plastic pipes are not good either. Foshan Rifeng and Jinde used them for only four to five years in the north and south of the Yellow River, and only two or three years in the northeast. .
But inside, for aesthetic reasons and tohigh indoor temperature, PPR or aluminum-plastic pipes can be used.
What material is the water pipe of the solar water heater made of?
Since the solar water heater is installed outdoors, it is recommended to use aluminum-plastic pipes.
1. The low temperature resistance of aluminum-plastic pipes is higher than that of PPR pipes. PR is fragile when cold (the fragility point is -20°C), special care is therefore required during construction in winter (below 5°C). Aluminum-plastic pipes have no cold brittleness (the brittle point is -70°C) and can be easily installed below -20°C.
2. The expansion coefficient of PPR pipes is high. Since the piping system is rigid and straight, the PPR pipe itself cannot digest the deformation, so it is easy to cause bending, deformation and leakage.ite of the piping system. Aluminum pipes are made of aluminum. Taken together, their linear expansion coefficient with aluminum is approximately 0.025 mm/m.
The temperature is ℃, which is 1/6 of the PPR pipe. Affected by temperature changes, the deformation is small, and the aluminum tube is a flexible coil. The tube itself can absorb a certain amount of deformation and will not cause thermal deformation to form the piping system.
3. PPR pipe has poor aging resistance. The PPR molecular chain structure - (-CH2—CH-)n- contains a large number of unstable tertiary carbon atoms, which are more sensitive to CH3 light and oxygen. , and impurities (such as copper, iron ions) and aging. Therefore, the PPR product manual generally stipulates that the open air stacking time should not exceed six months.
The PE plastic usedin aluminum-plastic composite pipes has a molecular chain structure - (-CH2-CH2-)n-, which is the most stable structure among plastics, and the aluminum layer in the middle of the aluminum-plastic pipe insulates the inner and outer layers, the outer plastic layer can add sufficient stabilizers to resist aging by light and oxygen without affecting the hygiene of the inner layer that comes into contact with water.
Detailed information:
The advantages of aluminum-plastic pipes can be summarized in the following three aspects:
1. Excellent hygienic performance: the outer layer made of aluminum-plastic. Plastic pipes are made from a special polyethylene material, which is clean and non-toxic. More importantly, the middle layer oftube is made of aluminum, which not only isolates light but also blocks oxygen. It is well known that the environment in which microorganisms grow requires light oxygen. The aluminum interlayer of aluminum pipes will eliminate the growth of microorganisms and algae that plastic pipes cannot reach.
Not only do plastic pipes contain high amounts of antioxidants, which prevent material degradation, but when the antioxidants are extracted from the water held in the pipes, they can also cause water pollution. the water. In addition, because there is no photoresistant material in the entire plastic pipe, microorganisms are easily generated, causing secondary pollution of water quality.
2. Excellent high and low temperature resistance: long-term use temperature is 95°C (50 years, IMPa), the temperatureMaximum use temperature is 110°C and the aluminum plastic pipe has a low coefficient of thermal expansion. . It is equivalent to the thermal expansion coefficient of aluminum and only one-sixth of the total number of plastic pipes. When the temperature changes, the deformation is very small and the aluminum plastic pipe is a flexible coil. The pipe itself can absorb a certain amount of deformation and will not cause thermal expansion deformation of the piping system.
The whole plastic pipe has poor high and low temperature resistance. The long-term use temperature of PPR is only 70 degrees (50 years, IMPa), and the maximum use temperature is 95 degrees. At the same time, the expansion coefficient of PPR pipes is high, and when the external water temperature (hot and cold water) changes, a large initial deformation occurs. Since thes PPR pipes are straight and rigid pipes, they cannot absorb deformation, which can easily cause the system to bend, deform or even leak.
3. Long service life: PE plastic multi-tube aluminum mold, the molecular chain structure (CH2 - CH2 -) used is relatively stable in the plastic, and. As an insulation layer between the inner and outer aluminum layers of the tube, plastic can be added to the outer layer to repel light stabilizers and oxygen aging without affecting the hygiene of the internal contact with water, thus improving its anti-aging performance.
Solar water heater\x0d\There are many options for installing water pipes, such as PPR water pipes, copper pipes, pipes copper-plastic pipes (aluminum-plastic pipes), PVC pipes, iron pipes, etc. \x0d\Actually, coConsidering various factors, PPR water pipes are quite ideal. The reason is also very simple. Firstly, the quality of good PPR water pipes is very reliable, which is quite comparable to that of copper pipes. Secondly, the price is more acceptable and much lower than copper pipes; that it is healthy, without any rust or patina. \x0d\Note, the water line must be 6 points. PPR water pipes are divided into cold water pipes and hot water pipes. The key is the thickness of the pipe wall. It is recommended that everyone use hot water pipes for drainage at home. the price is not much more expensive. \x0d\ Considering that solar water pipes must be antifreeze, meaning they cannot freeze and crack under normal circumstances, there are only three types of pipes on the market: true reticulated pipes PEX, thePERT pipes and PB pipes. . \x0d\At present, most of the market uses PEX as solar water pipes, because it is frost-resistant and the price is relatively low. However, over the past couple of years, many manufacturers have significantly reduced their degree of crosslinking. in order to be competitive in the market, thereby reducing costs. But at the same time, its antifreeze performance has also been significantly reduced. If you use it, it is recommended not to choose one that costs less than 140 yuan. the anti-freeze performance of PERT is better than PEX, but the cost is relatively higher, so it is rarely used for solar energy in the market, and PB pipe should be regarded as the best anti-freeze pipe in the market. It is now used in many high-end underfloor heating projects. Of course, its cost is higher and it cannot be promoted in the sectorsolar energy today. \x0d\ Therefore, it is recommended to choose higher quality PEX cross-linked pipes, as long as you are not trying to be cheap. \x0d\PPR cannot be used as solar water supply and drainage pipes. It will freeze and crack in one winter in the north (it can be used in the south). \x0d\Aluminum-plastic pipes are no good either. Foshan Rifeng and Jinde used them for only four to five years in the north and south of the Yellow River, and only two or three years in the northeast. \x0d\But inside, for the sake of appearance and high indoor temperature, PPR or aluminum-plastic pipes can be used.