According to the different heating forms, instant electric water heaters can be divided into the following types:
1: naked heating wire heating electric water heater.
2. Electric film heating electric water heater.
3. Electric heating tube electric water heater.
4. Semiconductor ceramic heating electric water heater
5: 3dmax integrated quick heating system intelligent constant temperature instant heating electric water heater. The four schools of hot electric water heaters are metal tubes, glass tubes, cast aluminum and semiconductor ceramics.
1. "Metal Pipe" School
The "metal tube" school refers to the enterprise camp where the heating element of instant electric water heater is made of metal.
The main materials on the market are stainless steel and copper. Compared with stainless steel, red copper has good ductility and can be made into seamless copper tube, which enhances thermal conductivity and effectively prevents water leakage. However, because the price of copper is higher than that of stainless steel, most enterprises use stainless steel as the liner and heater for cost reasons. Advantages of the "metal pipe" school: the technology comes from the storage water heater, and the heating pipe is directly immersed in water, with high thermal efficiency, rapid temperature rise and mature matching. It is a widely used heating technology at present. The weakness of "metal tube" school: metal heating elements can not avoid scaling problems, which will bring hidden dangers of electricity leakage and high maintenance rate.
New technology adopted by metal tube school
The new technology of instant electric water heater —— split pipe structure design has the characteristics of high thermal efficiency, uniform heating, pressure resistance, high temperature resistance, long service life and low noise, which greatly improves the stability and durability of the whole machine and equips the water heater with "Pentium core". Three-stage cycle
Multi-gear control, different gears are loaded by different heating groups, and the service life of heating pipes doubles. Water rotating structure
After the water enters the heater, it rotates at high speed, which makes the heat exchange more fully and evenly and greatly improves the thermal efficiency. "Robot" welding
Advanced robot automatic welding technology greatly improves welding efficiency, quality and stability. Laser welding
Using laser welding technology not only makes the process beautiful, but also greatly improves the anti-corrosion and anti-scaling ability of the heater at high temperature. Tube separation structure
With the design of pipe body separation structure, it is detachable and washable, which can better clean the metal heating element-cleaning scale, reduce the maintenance cost and solve the inevitable scaling problem in the early stage. 2. The "glass tube" genre
The "glass tube" school refers to the enterprise camp where the heating element material of instant electric water heater is nonmetal.
The main nonmetallic heating elements in the market are made of crystal, glass and ceramics. A layer of heating material (resistive film) is attached to the outer wall of nonmetallic pipeline made of nonmetallic materials in the form of high temperature sintering, normal temperature coating or printing. As the material of electric water heater heater, crystal is the best medium in terms of safety and heat conduction, and "QSC" nonmetal crystal heater is the most advanced in application technology. Advantages of the "glass tube" school: the outer wall of the glass tube is coated with a resistive film, water flows through the inner wall of the glass tube, and water and electricity are separated. Generally, the safety performance is good. The weakness of the "glass tube" school: poor thermal conductivity, which will cause a lot of energy waste and low thermal efficiency when heating; When the outer wall is heated, the outer temperature of the tube wall is extremely high, cold water passes through it, and the inside of the glass tube shrinks and expands, resulting in great torsional stress, which is easy to cause the glass tube to burst. Even if it does not burst, it will greatly shorten the service life of the glass tube; Glass tube has high hardness, but low toughness and limited bearing capacity. When the tap water pressure is too high, it is easy to break.
3. "Cast Aluminum" School
The "cast aluminum" faction refers to the enterprise camp in which the heating element, the main component of the instant electric water heater, is made of tubular electric heating element and metal aluminum die-casting.
Based on the increasingly exposed defects of the traditional heating method of instant electric water heater, another heating technology of cast aluminum-3D MAX integrated extreme speed heating system, namely three-dimensional molding and alloy aluminum integral casting, has appeared in the market. It is a high-tech product developed by Zhongshan Hangong Electric Appliance Co., Ltd. and obtained the national patent certificate. Technical characteristics of cast aluminum
Bend the tubular electric heating element and stainless steel water channel into the mold, and die-cast it into a flat or cylindrical shape with high-quality metal aluminum as the shell (mainly used for instant faucet). It can be closely attached to the heated body, and it is an efficient heater with uniform heat distribution and excellent thermal conductivity, which ensures the uniform temperature of the hot surface and eliminates the cold hot spots of the heater. superiority
The waterway is completely isolated from the heating element, and the water gradually heats up when flowing in the pipeline, which belongs to the principle of low-temperature circulating "living water" heating, avoiding the scale problem caused by high-temperature still water heating, and theoretically, no scale is generated at all; It has the advantages of long service life and corrosion resistance. disadvantaged
The heating element is biased, the process is complex, the cost is high, and it takes time to popularize the new technology. 4. Institute of Semiconductor Ceramics
brief introduction
Semiconductor ceramics are intelligent electrothermal materials developed and patented by Shanghai Meilan Electric in 2008. It will show different electrothermal characteristics according to different temperatures and automatically change its own power.
Advantages: there is no concept of dry burning, which completely solves the problem of fire caused by dry burning. Because the material itself will control the temperature not to exceed 260 degrees Celsius, even if it is electrified for a long time, there will be no problem. Semiconductor has a long life, with a design life of 654.38+ million hours. Even in the case of water-free heating, it can still be heated continuously for 5000 hours without damage, which is equivalent to a domestic water heater working continuously for 20 years. Tubular heat exchange, permanent isolation of water and electricity. The water flow pipeline is completely separated from the ceramics, and the water pipe is a high-finish metal pipe, so there is no potential risk such as pipe bursting and water leakage. It is difficult to scale when heated at low temperature. The maximum temperature of the heater is 260 degrees Celsius, which is much lower than the temperature of the general heater of 600- 1200 degrees Celsius, and it can adapt to different water quality all over the country. Intelligent materials with strong adaptability to voltage fluctuation. Semiconductor ceramics can automatically adjust their own resistance characteristics with temperature, eliminate the influence of voltage change on power, and solve the long-term technical problem of "low voltage and not hot water" in winter. High pressure-bearing structure, with water pressure resistance above 16 kg, suitable for various environmental water pressures. Disadvantages: In the initial stage of cold water start-up, it takes a long time to reach the appropriate water temperature, with high manufacturing cost and various flue types.
The smoke outlet is large, the smoke pipe is thick and the wind resistance is poor. Outdoor airflow is easy to blow into the water heater through the thick smoke pipe, causing accidental flameout or flashback to damage the water heater, so it cannot be installed on high floors (only below 7 floors). Because it is an open combustion chamber, the combustion efficiency is not high, and the energy efficiency level is level 3, so it is now in the elimination period.
Forced discharge type
It adds a forced exhaust fan on the basis of the hood, and its function is to suck the air outside the water heater into the combustion chamber to help combustion (high combustion efficiency, energy efficiency level 2), and at the same time, forcibly exhaust the burned waste gas outside. Because the wind pressure in the water heater is large and the smoke outlet is thin, the outdoor end is connected with a special windproof smoke pipe. So it can be installed in an apartment with a high elevator. Constant temperature type: on the basis of forced exhaust machine, two main components are added. Microcomputer display controller and gas proportional valve. When the water pressure, air pressure and external temperature change, the microcomputer controls the gas proportional valve to automatically adjust the size of the gas to keep the water temperature constant (the constant temperature speed depends on the accuracy of the gas proportional valve). The reaction time is 5-25 seconds). 10 liter constant temperature water heater, if the water is reduced by half, the capacity of 10 liter is changed to about 5 liters, which means that the constant temperature effect of the water heater is better. Like washing hands and dishes at ordinary times, the thermostat with low water pressure can start working normally without the maximum amount of water, and water and gas are the same, which can save water and gas to some extent. This is impossible for flue machines and forced exhausters. It can be set according to the temperature, and the temperature is constant.
Condensing type
The function of condenser is high efficiency and energy saving (national energy efficiency is 1). Based on the thermostat, a condensing heat exchanger is added to the condenser. Its function is to recover the high-temperature waste gas that should be discharged from the condenser and then absorb the heat, and at the same time separate the condensed water from the high-temperature waste gas to protect the water heater from corrosion and prolong the service life of the water heater.
Formation of condensed water: There is water in the air. When the high-temperature waste gas with 100 -200 degrees meets the condensation water tank with only 10-20 degrees, the moisture in the high-temperature flue gas instantly condenses into water droplets and is discharged from the water heater. The spiral V-shaped condenser tube of Sakura Snow is inverted pyramid-shaped, which can absorb heat in the largest area and discharge condensed water more smoothly. The thermal efficiency reaches 103%.