Classification of electric water heater
According to the water storage mode, the electric water heater can be divided into three types: hot type and volume type (also known as water storage type or heat storage type), fast heat type (also known as semi water storage type); Volume type is the main form of electric water heater. According to the different installation methods, it can be further divided into vertical, horizontal and floor type. According to the pressure bearing type, it can be divided into simple (open type) and pressure bearing type (closed type). According to the volume size, it can be divided into large volume and small volume type.
1. That is, the choice of heat type and water storage type
Electric water heater has the advantages of safe, hygienic, free from water pressure, water supply at any time, easy to adjust water temperature, etc. it has been widely used in developed western countries, that is, the hot water heater is small in volume and does not need to be preheated, but it has a large power, usually above 4-6kw, and the working current is up to 18-27a. Most of the power supply lines in China can only bear 15A current, And water temperature is easily affected by water pressure in use. The power of water storage water heater is usually 1.2-2kw and the current is 6-9A. The general home line can meet the requirements. The water storage type has the automatic constant temperature insulation, and can also provide hot water when the power is cut off, and can be used as the hot water supply center and supply multiple water. But it is large and needs preheating.
2. The choice of closed and open
Water storage water heater is divided into two types: closed type and open type. The open water heater can not supply water at multiple places at the same time because it is not pressure resistant; The enclosed electric water heater can withstand pressure and supply water at multiple places at the same time. The closed type should be selected as the best pressure vessel, and the round tank structure can bear the maximum pressure, so the design of the round tank is the most reasonable.
3. Choice of the inner bladder
The inner tank of water storage electric water heater is used for water storage. It must have the characteristics of heat preservation, pressure resistance, rust free, no scale and no water seepage. Once damaged, it is difficult to repair, and its life depends on the material and manufacturing process of the inner tank. The key is to choose a good inner tank. At present, there are several kinds of internal tanks of electric water heater in the market:
(1) . galvanized plate liner: the zinc protective layer is only 0.06mm, and it is not rust proof after forming, easy to rust and short life.
(2) Stainless steel inner liner: good material, not easy to rust; But the hidden danger of welding seam is difficult to find. After many times of heat expansion and contraction, chromium in stainless steel will be corroded by chloride ions in tap water and cause weld water leakage.
(3) . hot dip galvanized coating with antirust resin liner: after the inner liner is formed, the thickness of zinc alloy protective layer is more than 0.7mm, and the zinc containing gold surface is covered with antirust resin, with short service life.
(4) Enamel liner: the glaze on the surface of the inner liner is non-metallic material, which is neither rusted nor scale, and made of thick steel plate, with strong pressure resistance. High glaze steel liner is the highest level of enamel liner, not only good corrosion-resistant shape, but also a certain moisture retention effect, can be used for a long time.
4. What is the key to the quality of electric water heater?
As the quality of refrigerator is the compressor, the quality of electric water heater is the inner tank of water heater. The inner tank of electric water heater is used for water storage. It must have the characteristics of heat preservation, pressure resistance, no rust, no scale and no water seepage. To achieve this characteristic, the key to achieve this characteristic lies in the selection of the inner liner material and the production process of the inner tank.
5. Is it round or square?
Nowadays, the most high-quality international famous electric water heaters are round tank design, not square design. The reason is simple. Because only the design of round tank is the most uniform and can bear high pressure, while the square or other shape is not evenly stressed and can not withstand high pressure, so the pressure resistance performance of electric water heater reaches the strongest, and the best choice is circular design.
6. What is the water and electricity separation heater
The real water and electricity separation heater is to put the electric heating wire into the ceramic pipe groove, the ceramic pipe is placed in the stainless steel cylinder, the outer wall of stainless steel contacts with water to ensure the absolute separation of water and electricity, and there is no worries about the use.