What are the advantages and disadvantages of the f

2022-07-29
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What are the advantages and disadvantages of the four components of air source heat pump

the air source heat pump is mainly composed of compressor, expansion valve, fin heat exchanger and casing heat exchanger. It drives the compressor and motor to do work through the input of electric energy, so that the fin heat exchanger can absorb heat and the casing heat exchanger can release heat. The heating effect is as high as 3. Guarantee the quality, guarantee the service life, and ensure that the price is not charged indiscriminately or raised by 80%. It is one of the most energy-saving heat source equipment at present. It is safe and Environmental protection and high efficiency are its main characteristics

the strength is 5 times that of steel

what are the advantages and disadvantages of the four components of air source heat pump

1. Heart component compressor

as the heart component of the air source heat pump, the compressor is equivalent to the CPU of the computer and the heart of the human body. It can drive the circulation of the refrigerant, realize the process of thermal expansion and cold contraction, and make the refrigerant realize the physical changes of evaporation, heat absorption, condensation and heat release. At present, the commonly used compressor brands include tanlun compressor, Hitachi compressor, Sanyo compressor and Daikin compressor, which are known as the four major brands in the industry, In the heat pump industry, the GuLun brand compressor is the best

2. Throttling device - capillary electronic expansion valve and thermal expansion valve

throttling valve can generally be divided into capillary throttling, thermal expansion valve throttling (internal balance and external balance) and electronic expansion valve throttling. By changing the pressure change of refrigerant, the refrigerant can realize the process of liquefaction and gasification, and detect and collect data on Superheat or temperature difference between inlet and outlet air, return air temperature and its set value, After being processed by microprocessor, the opening of expansion valve is controlled to meet the requirements of system load. The advantage of electronic expansion valve is that it can accurately control the refrigerant flow, so as to accurately control the evaporation temperature. It is usually used where the temperature control accuracy is required to be high according to the requirements of some product standards and the needs of users and enterprises

the electric expansion valve with key speed regulation and digital display of experimental force displacement can work normally above -70 ℃, but the thermal expansion valve can only reach -60 ℃ at least. Capillaries are used in small refrigeration systems (simple in structure and not adjustable. After all, capillaries are only a small copper tube)

expansion valve is used in large and medium-sized refrigeration systems (relatively complex and adjustable). Besides controlling the evaporator, the adjustment of refrigerant flow can also be used to adjust the condenser. When the evaporation condition allows, if the condensation pressure is too high, the expansion valve can be properly closed to reduce the refrigerant flow in the system and the condenser load, so as to reduce the condensation pressure and realize the efficient and reliable operation of the air energy water heater unit

3. Heat release component - casing heat exchanger

the casing heat exchanger is the carrier that transfers part of the heat of the hot fluid to the water supply. It selects high-efficiency threaded copper pipe and wraps it with treated galvanized steel pipe to realize the process of refrigerant water inclusion, so that the high-temperature refrigerant gas can fully contact with water and achieve better heat transfer effect

advantages of casing heat exchanger:

◆ simple structure and free increase and decrease of heat transfer area. Because it is composed of standard components, no additional processing is required during installation

◆ high heat transfer efficiency. It is a pure countercurrent heat exchanger. At the same time, it can also select the appropriate section size to improve the fluid velocity and increase the heat transfer coefficient of the fluid on both sides. Therefore, it has good heat transfer effect. For liquid-liquid heat transfer, the heat transfer coefficient is 870 ~ 1750w/(M2 ℃). This is especially suitable for the heat transfer of high pressure, small flow and low heat transfer coefficient fluids. The disadvantage of the tubular heat exchanger is that it occupies a large area; The metal consumption per unit heat transfer area is about 5 times that of shell and tube heat exchanger; Many pipe joints, easy to leak; High flow resistance

◆ simple structure, wide working range, convenient increase and decrease of heat transfer area, both sides of the fluid can increase the flow rate, so that both sides of the heat transfer surface can have high heat transfer coefficient. The disadvantage is that the metal consumption per unit heat transfer surface is large. In order to increase the heat transfer area and improve the heat transfer effect, various types of fins can be added to the outer wall of the inner tube, and a film scraping disturbance device can be added to the inner tube to adapt to the heat exchange of high viscosity fluid

disadvantages of casing heat exchanger:

◆ it is troublesome to repair, clean and disassemble, and it is easy to cause leakage at the detachable connection

◆ in production, there are many materials with limited selection. As most of the casing heat exchangers are inner tubes, welding is not allowed, because welding will cause thermal expansion and cracking. However, most of the casing heat exchangers are bent and coiled into snake tubes in order to save space, so there are many special corrosion-resistant materials that cannot be produced normally

◆ there is no unified welding standard for the casing heat exchanger in China, and all enterprises choose the welding method based on the experience of other heat exchange products. Therefore, it is common for various problems to occur at the welding position of the casing heat exchanger, which requires frequent inspection and maintenance

4. Air absorbing component - fin heat exchanger

the fin heat exchanger mainly adopts aluminum foil with clean water film and a bridge mounted ventilation system to make the air fully contact with the heat transfer area and more efficiently absorb the heat in the air

characteristics of fin heat exchanger:

◆ high heat transfer efficiency. The boundary layer is constantly broken due to the disturbance of fins to the fluid, so it has a large heat transfer coefficient; At the same time, because the clapboard and fin are very thin and have high thermal conductivity, the plate fin heat exchanger can achieve high efficiency

◆ compact. As the plate fin heat exchanger has an expanded secondary surface, its surface area can reach 1000m2/m3

◆ lightweight. The reason is that it is compact and mostly made of aluminum alloy. Now steel, copper and composite materials have also been mass produced.

◆ through the arrangement and combination of flow channels, it can adapt to different heat exchange conditions such as countercurrent, cross tidal, multi stream and multi-path flow. The combination of series, parallel and series parallel between units can meet the heat exchange needs of large equipment. In industry, it can be finalized and mass produced to reduce costs, and the interchangeability can be expanded through building block combination

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