For air conditioners with the same energy consumption level, the difference between fixed frequency and variable frequency, and the difference in power consumption

The so-called "variable frequency air conditioner" is a concept derived from comparison with the traditional "fixed frequency air conditioner". As we all know, my country's power grid voltage is 220 volts and 50 Hz. Air conditioners working under these conditions are called "fixed frequency air conditioners". Since the power supply frequency cannot be changed, the compressor speed of the traditional fixed-frequency air conditioner basically remains unchanged. It relies on the constant "starting and stopping" of the compressor to adjust the indoor temperature. When it is turned on and off, it is easy to cause the room temperature to become hot and cold. And consume more power. In contrast, the "variable frequency air conditioner" inverter changes the compressor power supply frequency and adjusts the compressor speed. The purpose of controlling the room temperature is achieved by relying on the speed of the compressor speed. The room temperature fluctuation is small, the power consumption is small, and the comfort is greatly improved. The inverter air conditioner using variable frequency control technology can automatically select heating, cooling and dehumidification operation modes according to the ambient temperature, so that the room can quickly reach the required temperature in a short time and operate at low speed and low energy consumption with a small temperature difference. Fluctuation, achieving fast, energy-saving and comfortable temperature control effects.

When the power supply frequency is high and the compressor rotates quickly, the air conditioner has a large cooling (heat) capacity; when the power supply frequency is low, the air conditioner has a small cooling (heat) capacity. This is the so-called "fixed frequency" principle. The core of the inverter air conditioner is its frequency converter. The frequency converter is a high-tech technology that came out in the 1980s. It realizes automatic adjustment of the motor's operating frequency by converting current, changing the fixed grid frequency of 50Hz to 30 to 130Hz. The frequency of changes has completed a new revolution in air conditioning. At the same time, it also makes the power supply voltage range reach 142V to 270V, completely solving the problem of air conditioners not working properly due to unstable grid voltage. Every time the inverter air conditioner is started to be used, it usually allows the air conditioner to perform heating or cooling at the maximum power and maximum air volume, quickly approaching the set temperature. Since the inverter air conditioner increases the heating capacity at low temperatures by increasing the working frequency of the compressor, the maximum heating capacity can reach 1.5 times that of air conditioners of the same brand and level, and it can still maintain good heating at low temperatures. Effect. In addition, the general split machine only has four wind speeds for adjustment. When the indoor fan of the inverter air conditioner runs automatically, the rotation speed will change within the 12 wind speed range according to the working frequency of the compressor. Since the fan speed is different from the air conditioner, The capacity coordination is more reasonable, achieving quiet operation with low noise. When the air conditioner operates at high power and quickly approaches the set temperature, the compressor will operate at low speed and low energy consumption, using only the required power to maintain the set temperature. This not only stabilizes the temperature, but also avoids the attenuation of life caused by frequent starting and stopping of the compressor, and greatly reduces power consumption, achieving high efficiency and energy saving.

The "variable frequency air conditioner" adopts relatively advanced technology, with a small voltage when starting, and can be started under low voltage and low temperature conditions. This is not suitable for some areas due to unstable voltage or low indoor temperature in winter. The situation where the air conditioner is difficult to start can be improved to a certain extent. Due to the stepless speed change of the compressor, it can also adapt to the cooling and heating needs of a larger area. However, the price of "variable frequency air conditioners" is usually about a thousand yuan higher than that of "fixed frequency air conditioners". Therefore, you should also pay attention to the following points when purchasing "variable frequency air conditioners":

1. DC variable frequency energy saving 48% are generalizations. Experts from the Chinese Refrigeration Society pointed out that the polarity of the two electrodes of DC is fixed, the current only flows in one direction, does not alternating, and has no frequency at all. How to talk about frequency conversion? The so-called "DC variable frequency air conditioners" currently promoted on the market are actually DC speed-adjustable air conditioners, and the DC speed-adjustment technology used in them is far superior to frequency modulation technology. However, in order to make full use of people's thinking patterns, marketers put the original frequency conversion hat on it without thinking, which made a joke. According to reports, DC speed regulation only undergoes one voltage conversion, so the energy loss is smaller than that of frequency modulation speed regulation.

In addition, since the rotor of this DC motor is permanent magnet, it saves the current consumption of the rotor of the three-phase AC asynchronous motor. Therefore, the electrical efficiency from the grid power supply to the motor is higher than that of the frequency modulation speed regulation method, saving a lot of money. A certain amount of energy. However, some manufacturers exaggerate the energy saving of the internal adjustment system into the energy saving of the entire machine, so there is a saying that the energy saving is 48%. Experts say that energy saving mainly depends on the design and configuration of the refrigeration system, as well as the size of the system's refrigeration coefficient. It is not difficult to see that the main purpose of improving the constant speed air conditioner into a variable speed air conditioner is to improve its automatic adjustment method to improve the quality of the machine, rather than to save energy. However, it should be pointed out that speed regulation is only a basis for improving the operating quality of air conditioners, and the real improvement depends on the matching of the refrigeration system. The key component for regulating the cooling capacity of the system is the throttling and pressure reducing element. If it is not changed from a capillary tube with constant damping to an electronic pressure reducing valve (expansion valve) with adjustable damping that is suitable for the speed regulation range, then this kind of A speed-adjustable air conditioner does not make much sense, and may even consume excess power required for internal conversion. The efficiency ratio of today's air conditioners is generally between 2.6 and 2.9, and rarely exceeds 3.0. Therefore, the promotion of energy saving of 48% is inaccurate.

2. "Working salary variable frequency" does not reduce the price but reduces the cost. The price of "working salary variable frequency" air conditioner is about 1,000 yuan lower than the price of most "variable frequency" air conditioners, mainly because it reduces the cost. First of all, most of the current inverter air conditioners are dual-rotor, and most of them use imported compressors, while the "working salary inverter" uses Shanghai Hitachi single-rotor compressor. The price difference is about a few hundred yuan. Secondly, there are two types of throttling devices, one is the expansion valve and the other is the capillary tube. Generally, fixed frequency air conditioners use capillary tubes, while variable frequency air conditioners use expansion valves. The "working salary variable frequency" uses capillary tubes, which cost more than ten yuan, while the expansion valve costs one or two hundred yuan.

The third is the frequency converter. Generally, frequency converters are imported, while the "work salary frequency converter" uses domestic ones. At this point, in addition to the difference in cost, there is also a difference in frequency conversion range. Fourth, the "worker's salary inverter" is a single-cooling inverter that is not used in winter. The commonly used four-way valve has been changed to a straight-through one. A four-way valve costs hundreds of yuan. Together, these items reduce the cost by an estimated 800 yuan. about. 3. Do not use the maximum cooling capacity as the criterion for purchasing. There are differences in the selection of inverter air conditioners and ordinary air conditioners. When purchasing, the power of the inverter air conditioner should be determined based on the area of ??the room, rather than the maximum cooling capacity. Because the inverter air conditioner does not work under maximum cooling conditions for a long time, its maximum cooling capacity is limited to the cooling capacity that can be achieved in a short time in a room with a specific area, and it is necessary to avoid using it in situations that exceed the area.