Solar water heaters are convenient, environmentally friendly and safe, and are well received by people. There are many types of solar water heaters. Currently, solar water heaters can be classified as follows.
According to the heat collection part, it can be divided into vacuum glass tube solar water heaters and metal flat plate solar water heaters. The evacuated glass tube solar water heater currently has the heat collection part with the highest heat absorption efficiency. Its advantage is that there is no need to add an insulation layer to the heat collection part, and the current vacuum glass tube has excellent performance. terms of high temperature resistance, impact resistance and heat preservation. It is very good and is used by most solar water heater manufacturers. Its disadvantages are that it is relatively encumbersome and that scale easily accumulates in the pipe.
The working principle of metal flat plate solar water heater is to cover a sheet metal with excellent heat transfer performance with a heat absorbing coating and utilize the heat transfer property. heat from the metal to transfer the absorbed heat. to the water tank. Its advantages are that it is aesthetic, easy to install, robust and can be transformed into a flat screen. The downside is that insulation is expensive and the cost is high.
Structurally, it can be divided into ordinary solar water heaters and split-type water heaters. Ordinary solar water heaters insert evacuated glass tubes directly into the water tank and use the circulation of heated water to increase the temperature of the water in the water tank. This is the most conventional water heater currently used by manufacturers. GeneraHowever, this type of water heater can only be used on the top floor of the house and the roof area is limited.
The split type water heater was born to solve the problem that users who are not on the top floor can use solar water heaters. There are two circulation methods for split solar water heaters: one is based on natural water circulation, which has very low heat exchange efficiency and is far from meeting water needs; the other is based on heat exchange by pump circulation, which is also used; to solve the problem. Due to the low efficiency of natural circulation, the use of pump circulation can significantly improve the heat exchange of water.
Solar water heaters can be divided into pressurized solar water heaters and non-pressure solar water heaters based on the pressure of the water tank.Pressurized solar water heaters use a pressurized water tank to circulate water through pressurization, which is more convenient to use. Pressurized solar water heaters have high requirements for the sealing performance of the collector and water tank. At present, ordinary rooftop solar water heaters are generally non-pressure water heaters. Their water tanks have a pipe connected to the atmosphere. They use the height difference between the roof and the house to generate pressure when using water. Its safety, cost and service life are much better than pressure type.
According to the water flow mode, it is divided into three types: solar drying type, direct flow type and circulation type. The sun-drying solar water heater is a water heater that combines heat collection and heat storage into one. he canbe divided into shallow pool type, plastic bag type and cylindrical type according to different water tanks. The circulating all-glass vacuum collector tube solar water heater uses the high absorption rate and low emissivity of the vacuum collector tube to convert the absorbed solar radiation into thermal energy. It uses the different density characteristics of hot and cold water to form water in the. vacuum tube. Natural circulation causes the water temperature to gradually increase and reach a certain temperature. Circulating solar water heaters can be divided into natural circulation according to different circulation powers. There are three types: fixed temperature automatic circulation type and forced circulation type.