Why do the market recommend variable frequency air compressors?

Nov 14, 2024

1. What is a variable frequency air compressor?

A variable VSD screw air compressor controls the input voltage frequency according to load changes. It can maintain the stability of parameters such as pressure, flow, and temperature, thereby greatly improving the working performance of the compressor. There are many advantages of variable frequency air compressors. It can reduce the starting current of the motor, reduce the impact on the user’s power grid, automatically adjust the load to reduce power consumption, reduce losses, and extend the service life of the equipment.

2. How does variable frequency air compressor achieve energy saving?

Under most operating conditions, the user’s compressed air demand will fluctuate

to a certain extent. Traditional air compressors adjust the flow of the air compressor by adjusting the inlet valve of the air compressor to balance the actual gas output of the air compressor with the actual demand of the user. This adjustment method has the disadvantages of low efficiency and serious waste. The variable frequency speed air compressor adjusts the speed of the compressor motor by adjusting the frequency of the power supply, and then adjusts the speed of the air compressor host to make the actual output gas volume of the air compressor consistent with the actual gas consumption of the customer. This adjustment method can avoid a lot of energy waste in the inlet flow adjustment method, and is the most efficient air compressor flow adjustment method on the market.

3. How much electricity does a variable frequency air compressor save compared to an industrial frequency air compressor?

In industrial production, compressed air is a very important power source. The energy consumption of air compressors is the focus of enterprises. With the development of technology, variable frequency air compressors are gradually favored by the market. So, how much more electricity does a variable frequency fixed screw air compressor save than an industrial frequency air compressor? This article will compare it through actual calculation figures.

We first need to understand the working principles of variable frequency air compressors and industrial frequency air compressors. Industrial frequency air compressors use fixed frequency motors, and the operating speed cannot be changed, while variable frequency air compressors adjust the pressure by adjusting the motor speed. Therefore, variable frequency air compressors can adjust the operating state according to actual needs, thereby saving energy.

In order to more intuitively compare the energy consumption of the two, we can use a specific example. Suppose a company needs an air compressor with an exhaust volume of 10m³/min, working 24 hours a day, and the electricity price is 0.7 US dollars/kWh.

Industrial frequency air compressor: Taking a 75kW industrial frequency air compressor as an example, its rated power is 75kW, that is, the power consumption per hour is 75kWh. Therefore, the daily power consumption is 75kWh/h × 24h = 1800kWh. Calculated at an electricity price of $0.7/kWh, the daily electricity bill is 1800kWh × $0.7/kWh = $1260.

Variable frequency air compressor: After adopting variable frequency technology, the operating efficiency of the air compressor is improved. Assuming that the operating efficiency of the variable frequency air compressor is 80%, the power consumption per hour is 75kWh × 80% = 60kWh/h. Then, the daily power consumption is 60kWh/h × 24h = 1440kWh. Calculated at an electricity price of $0.7/kWh, the daily electricity bill is 1440kWh × $0.7/kWh = $1008.

By comparison, it can be seen that the variable frequency air compressor saves 1260 dollars – 1008 dollars = 252 dollars in electricity per day compared with the industrial frequency air compressor. If long-term operation and energy saving effects are taken into account, the electricity savings will be even more considerable. If calculated based on 365 days a year, the variable frequency air compressor saves 252 dollars/day × 365 days = 92180 dollars in electricity per year compared with the industrial frequency air compressor. In addition, the variable frequency air compressor has higher operating efficiency and can also improve the quality and stability of compressed air, bringing more benefits to the enterprise.