Maglev central air conditioner refers to the central air conditioner that adopts maglev frequency conversion technology. Maglev central air conditioner adopts maglev oil-free operation technology, full DC frequency conversion technology, high-efficiency heat exchange tube design, secondary enhanced subcooling technology of refrigerant, centralized control technology, aerospace technology, etc. technology. With ultra-high energy efficiency, it is the air conditioner with the highest level of energy efficiency in the central air conditioning industry.
The high-temperature and high-pressure refrigerant is discharged from the air-conditioning compressor, enters the condenser, releases heat to the copper tube cooling water, condenses into medium-temperature and high-pressure refrigerant liquid, and then reduces the pressure through the shut-off valve into low-temperature and low-pressure liquid, which enters the evaporator, and flows from the flow in the evaporator shell. The chilled water in the copper tube absorbs heat, vaporizes it into a low-temperature and low-pressure gas, and then sucks it into the compressor. After secondary compression in the compressor, it is discharged into high-temperature and high-pressure gas.
Magnetic levitation air conditioner is a high-efficiency energy-saving central air conditioner with magnetic levitation centrifugal compressor as the core technology. It uses the radial bearing and axial bearing composed of permanent magnets and electromagnets to form a numerically controlled magnetic bearing system to realize the frictionless movement of the moving parts of the compressor suspended on the magnetic lining, and the positioning sensor on the magnetic bearing is the motor rotor. Provides ultra-high-speed real-time repositioning to ensure precise positioning of the entire air conditioning system without lubricating oil.
Maglev technology has a long history, and maglev trains have been running in Shanghai for many years. This technology eliminates friction, improves mechanical efficiency and reduces mechanical failures. With the development and maturity of this technology, the air-conditioning industry has also ushered in the tide of maglev.
Since the air-conditioning system is a combination of many different equipment and pipes, a good combination can find the best balance between initial investment, operating costs, and operating effects.
Core Technology and Advantages of Magnetic Levitation Central Air Conditioning
1. The technical core of magnetic levitation air conditioners
The magnetic levitation compressor uses the radial bearing and axial bearing composed of permanent magnets and electromagnets to form a numerically controlled magnetic bearing system to realize the frictionless movement of the moving parts of the compressor suspended on the magnetic lining. The positioning sensor on the magnetic bearing is the motor rotor. Provides ultra-high-speed real-time repositioning to ensure precise positioning.
The magnetic levitation and DC frequency conversion technology of the compressor of the magnetic levitation centrifugal chiller greatly improves the performance of the unit. The compressor has a magnetic bearing, which is affected by magnetic force during operation. There is no direct contact between the shaft and the bearing. The double-stage cast aluminum impeller is directly embedded on the shaft, which reduces the energy loss caused by gear transmission. The compressor motor is a permanent magnet Synchronous motor, the compressor is powered by PWM (pulse width modulation technology) control voltage, which can realize variable speed operation. The inlet of the compressor is equipped with guide vanes to adjust the load of the compressor.
The anatomical diagram of the compressor of the magnetic levitation centrifugal chiller is shown in the following figure:
2. The technical advantages of magnetic levitation air conditioners
With the continuous development of science and technology, and the country’s vigorous promotion of energy conservation and consumption reduction, it is particularly important to apply new energy conservation technologies in all walks of life. Magnetic levitation technology was first used in the aerospace industry. With the further promotion of the technology, magnetic levitation technology has been successfully used in refrigeration and other industries.
Among them, the magnetic levitation centrifugal chiller can effectively overcome the problems of high noise and high energy consumption in the operation of the ordinary centrifugal chiller. Therefore, it is foreseeable that the magnetic levitation centrifugal chiller will replace the ordinary centrifugal chiller in the near future. Compared with the traditional unit, the magnetic levitation unit reduces the motor loss, frequency conversion loss, gear loss and bearing loss, so that the output energy loss is only 5.5%, compared with the traditional unit loss of 15.8%, the magnetic levitation centrifugal unit has obvious energy-saving advantages.
(1) Magnetic levitation central air-conditioning The entire air-conditioning system adopts magnetic levitation bearings to achieve zero friction, improve mechanical efficiency, increase speed, reduce impeller size, significantly reduce the volume and weight of the compressor, and the bearing is more durable than conventional bearings, making the central air-conditioning unit The operating life reaches 25 years;
(2) Using the stepless frequency conversion technology, the compressor speed can be infinitely small, the operating adjustment range is expanded, and the performance coefficient is high. At the same time, the unit realizes an oil-free system, and there is no lubricating oil in the refrigerant. maintenance costs;
(3) At the same time, the oil-free system can make the central air-conditioning system avoid the influence of the oil film covering the heat pipe during the shell-and-tube heat exchange, which will lead to the decrease of the heat exchange efficiency, and improve the heat exchange efficiency of the unit by more than 15%;
(4) The magnetic levitation air conditioner adopts full DC frequency conversion technology, which can realize high energy efficiency of ultra-high partial load through variable speed drive, and can realize partial load operation of the unit.
(5) The compressor only needs to meet the electromagnetic force supporting the weight of the rotating shaft, and the starting current and noise are low. The equipment does not need to be preheated before starting, and can start normally at low ambient temperature.
(6) The highest energy efficiency ratio of partial loads reaches 26, and the energy efficiency ratio of comprehensive working conditions reaches 11.98, and realizes remote control of intelligent cloud services of the Internet of Things, unattended.
(7) Due to its multi-head structure and precise control program, the magnetic levitation chiller can make the low-load operation time of the unit account for about 50% of the total operation time, and the high energy efficiency of partial load can be fully utilized.
3. Disadvantages of magnetic levitation machine
The initial investment in equipment is high. Because the magnetic suspension cooler integrates the magnetic suspension bearing and the digital frequency conversion control system, the initial investment of the equipment is greatly improved compared with the ordinary cooler.
When the air conditioner is not used for heating in winter, it is still necessary to energize the unit to prevent freezing; there are many accessories, such as water supply valve, exhaust valve, etc., individual models also need to install an expansion tank to increase leakage points. The outdoor body is large and heavy.