The whole system of air energy water heater is composed of heat pump host, water tank, solenoid valve, circulating pump and pipeline. The water tank of household machine can be divided into water circulation type, external coil type and internal coil type according to the heat transfer structure. There are also direct heated commercial engines. Whether they are direct heated or circular, their working principles are almost the same.

The water circulating heating in the household appliance is fast, safe, and has a long service life. There is no distance limit between the host and the water tank, but the production cost is relatively high, and the efficiency is very low. The most vulnerable thing is the circulating pump, which increases the power consumption, which is contrary to energy conservation. At the same time, circulating heating in the process of water use will lead to serious water mixing, and the heat source is also unstable. The external coil type has a long life and good safety performance, but it is slow to heat up and has a relatively long waiting time. Built in coil type heating is fast and efficient, but due to the influence of water quality, pipe material and thickness, there will be hidden dangers of coil corrosion and leakage after long-term use.

The direct heating air energy cold water will directly enter the main engine. Because the tap water itself has pressure, there is no need for a water pump. However, the circulating heat pump cold water enters the tank and the whole tank of water circulates. Therefore, the pump is required and the pump power is large, and the system is relatively power consuming. In the actual installation process, in order to ensure that users can wash hot water quickly and the temperature fluctuation of hot water is small, the circulating heat pump often needs to add an auxiliary water tank, and the water pump is needed between the two water tanks, so the system will be more complex and more power consuming. The circulating high-temperature refrigerant also conducts heat exchange with water at 15 ℃ at the beginning, but with its own work, the water temperature at which heat exchange takes place is getting higher and higher, and the heat exchange efficiency of the refrigerant drops. Especially when the water temperature rises to 50 ℃, the corresponding condensation temperature is as high as 75 ℃. The temperature of the refrigerant after heat exchange is still very high, at least 60 ℃. The heat release value of the refrigerant is obviously insufficient.

In commercial hot water units, the inlet water temperature of thermal units is low, but the outlet water temperature is relatively high (15 ℃~60 ℃). When the circulating hot water unit works initially, the inlet water temperature may also be 15 ℃. However, with each cycle, the inlet water temperature increases continuously. With the increase of temperature, the corresponding condensing temperature of the circulating hot water unit also increases rapidly.

The direct heating type usually improves the water temperature by controlling the water flow, so that the water temperature can be reached in one step. For the problem of water output, the water saving system can be adjusted through the water flow control valve to produce the same amount of hot water at the same temperature in the same time. Because the circulating heat pump system continuously heats the whole tank of water, the outlet water temperature is unstable, and users can use it from cold to hot; The outlet water temperature of the direct heat pump is constant, so there is no such problem.

The direct heating air energy water heater can solve the core technical problems of the heat pump when it works, and it is certainly the direction of the development of the air energy heat pump hot water technology in the future. However, the two operation modes of air energy heat pump have their own advantages, and the most important thing is to choose the appropriate product according to their actual needs.