Please don't let the air compressor displacement become a key word!

Please don't let the air compressor displacement become a key word!

For most unprofessional air compressor users, the standard for judging the energy efficiency of an air compressor is often to compare the exhaust volume data calibrated on the nameplate of the same air compressor. In fact, this is a serious misunderstanding!

Please don't let the air compressor "displacement" become a key word!

　　Okmarts.com editor first takes everyone to understand some basic knowledge about the energy efficiency of the air compressor.

　　The international general standard for measuring the energy efficiency of air compressors: SER specific power

　　·The smaller the SER, the better the energy efficiency and the more power saving;

　　·The larger the SER, the worse the energy efficiency and the more power consumption.

Air compressor energy efficiency grades are classified according to SER specific power. Taking oil-injected screw air compressors as an example, according to different rated pressure grades (0.7MPa, 0.8MPa, 1.0MPa, 1.25MPa) and different cooling modes (air-cooled) Or water cooling), the grading standard values ​​stipulated by the national standard are not the same. The current national standard is: GB 19153-2009 Energy efficiency limit value and energy efficiency grade of positive displacement air compressors. It should be pointed out that this standard does not specify the energy efficiency of variable frequency screw air compressors and low pressure machines (such as 3bar and 5bar models) The grading guide standard value, in other words: So far, no national standard for the energy efficiency classification of variable frequency air compressors and low-voltage models has been officially issued.

For a variable frequency air compressor, when any one of the pressure or speed changes, its SER specific power will also change; therefore, my personal opinion is that the energy saving of the variable frequency air compressor is more derived from Due to the following three main factors, the impact of SER specific power on energy saving is not the only factor.

　　 The flow adjustment of the variable frequency air compressor is good or bad. The better the follow, the lower the probability of no-load occurrence and the more energy saving (ie: PID control performance of the controller or inverter)

　　 There is only one pressure setting point for the variable frequency air compressor, and the power frequency air compressor must be equipped with a pressure band. Compared with the power frequency air compressor, the variable frequency air compressor can effectively reduce the energy loss caused by the pressure climb

The frequency conversion air compressor can be regarded as a stepless speed regulation equipment, and the relationship between its energy consumption and the gas consumption of the customer can also be regarded as a linear ratio; in layman’s terms: I consume as much electricity as you use. , To avoid the phenomenon of large horse-drawn carts or no-load, to achieve the purpose of saving energy for customers

　　Please don't let the "displacement" of the air compressor become a key word!

　　 SER specific power definition:

　　The input power of the whole machine required by the unit exhaust capacity;

　　 SER specific power calculation:

　　SER = machine input power / exhaust volume

　　 SER specific power unit:

　　KW/(m3/min)

　　 Machine input power:

　　 definition: refers to the total power of the air compressor running under rated pressure, including: the sum of the power of the main drive motor, cooling fan motor (air-cooled unit) and all power consumption components of the electrical system

　　Unit: kW

　　When purchasing an air compressor, customers need to pay attention to the actual input power of the whole machine when running at rated pressure, instead of simply looking at the displacement calibrated on the nameplate!

Please don't let the air compressor "displacement" become a key word!

　　Key point: (Never Forget)

　　The power calibrated on the unit nameplate ≠ the actual input power of the whole machine

　　 The higher the actual input power of the whole machine, the larger the displacement can be

The air compressor industry has gone through many years of development in China, and the relevant industry standards and specifications have become more and more perfect. The simple and crude "flow false standard" phenomenon of nameplate parameters has gradually been controlled and standardized; however, in fact, the nameplates of different brands of "same power" models Displacement can still make a big difference, ranging from 5-10% to as high as 15-25%. For the vast majority of unprofessional customers, it's a bit of a trap!

Please don't let the air compressor "displacement" become a key word!

　　 What is the truth? We must first patiently learn the concept of motor SF service coefficient:



　　 Motor SF service factor (Service Factor)

　　The motor service factor is a parameter to measure the intermittent overload capacity of the motor

　　The commonly used motor service coefficients are as follows: 1.15 / 1.25 /1.35

The motor is allowed to run within the service factor, but the motor continues to run under a load greater than the service factor 1, and its life will be shortened compared to running at the rated power; the more the excess, the greater the impact on the motor life Big.

　　 In short: the actual allowable operating power of the motor can be amplified by the SF service factor!

　　 Example:

　　 Motor nominal (rated) power: 90kW

When 　　SF=1.15, the actual limit operating power can reach: 90*1.15=103.5kW

When 　　SF=1.25, its actual limit operating power can reach: 90*1.25=112.5kW

When 　　SF=1.35, the actual limit operating power can reach: 90*1.35=121.5kW

and so:

　　 The 90kW air compressor can actually achieve 110kW or even larger air compressors through the amplification of the motor service coefficient;

　　 It is not difficult to understand why the flow rate of the "same model" air compressor can make a big difference!

　　Key points:

　　The actual allowable operating power of the motor can be amplified by the amplification of the SF service factor!

　　 The flow rate of the air compressor can be increased by amplifying the actual allowable operating power!

　　 Photos, comparison of nameplate photos of air compressor motors

　　 The motor service factor commonly used in LIUTECH air compressors: 1.15

　　Please don't let the "displacement" of the air compressor become a key word!

　　 Motor service coefficient used by other brands of air compressors in the industry: 1.25

Please don't let the air compressor "displacement" become a key word!

　　 　　 Motor service coefficient used by other brands of air compressors in the industry: 1.63