Working principle:
The system of magnetic levitation chiller technology is composed of four parts: rotor, sensor, controller and actuator. Assuming that the rotor is disturbed downward in the equilibrium position, it will deviate from its reference position. At this time, the sensor detects that the rotor deviates from the reference position. The microprocessor,which is used as the controller, converts the detected displacement into a control signal, and then the power amplifier converts this control signal into a control current, and the control current generates a magnetic force in the executive magnet, thereby driving the rotor back to the original balance position.
The magnetic levitation chiller can be roughly divided into compression part, motor part, magnetic levitation bearing and controller, and frequency conversion control part. The compression part is composed of a two-stage centrifugal impeller and an inlet guide vane, and an air supply port is reserved in the middle of the two-stage impeller, which can realize two-stage compression with intermediate air supply.
Features of Maglev centrifugal Chiller:
1. Use environmentally friendly refrigerant R134a, its ozone destruction (ODP) is 0, there is no ban timetable set in the new Montreal agreement, and it is a positive pressure refrigerant, the outside atmosphere is not easy to infiltrate the chiller system, the working pressure is low, and the container is safe. It is no appreciably toxic or flammable.
2. Low running noise
Low operating noise The noise is as low as about 70dB under full load, and the noise is even lower under partial load, which is about 20dB lower than that of conventional units. The feature of low operating noise makes the maglev compressor especially suitable for new construction and renovation of existing buildings in hotels and hospitals with strict noise requirements.
3. Oil-free operation
1) The shaft of the maglev compressor is not in contact with the bearing.
2) Compared with traditional bearings, magnetic suspension bearings have no mechanical friction, only airflow friction, and the energy loss of airflow friction is only 2% of mechanical friction;
3) 90% of compressor burning accidents are caused by failure of lubricating oil, and the magnetic levitation compressor eliminates a large number of failures caused by oil return problems.
4) When lubricating oil is used, a layer of oil film will be formed on the surface of the heat exchanger, which will block the heat absorption and heat release of the heat exchanger and affect the heat exchange effect of the heat exchanger.
4. Compact structure, small footprint
The benefit of the high speed of the magnetic levitation chiller is that the diameter of the impeller can be reduced to 5~8cm. The volume and weight of the magnetic levitation compressor are only about 20% of the conventional compressor with the same cooling capacity, which saves the floor space and makes the hoisting more convenient;
5. Efficient operation and stable performance
The use of two-stage compression can increase the theoretical refrigeration coefficient by about 10% compared with that of one-stage compression. The frequency conversion technology enables the unit to operate at low speeds at low loads (generally the lowest partial load is 10%) to avoid surges while maintaining high-efficiency operation.
6. Other advantages of actual runtime
The start of the maglev compressor is a soft start, and the start current is only 0~2A. The start current of the traditional compressor needs 200~600A. Moreover, in the actual operation, multiple modules of the magnetic levitation modular chiller start smoothly, without inrush current, and the previous one starts smoothly before the next one starts, making the operation safer;
When the power is suddenly cut off, the electricity in the capacitor in the compressor can ensure that the speed of the rotating shaft decreases slowly until it reaches zero, which avoids damage to the compressor caused by a sudden stop.
Application of Magnetic Levitation Chiller:
According to the characteristics of low noise and high energy efficiency ratio of the magnetic levitation chiller at partial load, it is especially suitable for the central air conditioning system of hospitals, large hotels, high-end office buildings, green energy-saving and environmental protection buildings, etc. It can give full play to the role of high efficiency and energy saving in partial loads, and greatly save the operating costs of the entire air-conditioning project. In addition, since the maglev frequency conversion centrifugal chiller has a high COP at an outlet water temperature of 3-18 °C, it can also be used in air-conditioning applications such as low-temperature air supply systems and independent fresh air systems.
Suspension chillers have outstanding advantages of high efficiency and energy saving. Compared with ordinary centrifugal chillers, magnetic levitation centrifugal chillers can reduce energy consumption by about 40% throughout the year, and the COP under nominal operating conditions can reach the first level of national chillers Energy efficiency level, its JPLV can reach 8.3-9, it is an energy-saving product worthy of vigorous promotion. At present, the magnetic levitation technology is still a new type of technology, which is mastered and produced by few domestic manufacturers, and the price of the unit is relatively expensive. With future development and cost reduction, maglev chillers have broad application prospects.
