Energy saving method for air compressor system without spending money
Many users regard the air compressor as just ordinary mechanical equipment such as motors and fans. If energy saving is mentioned, the first thing that comes to mind is to replace the more efficient energy-saving air compressor. This is true for general purpose devices. But it is not the same for air compressors. (This is not in line with the premise of "energy saving does not cost money" in this article)
01. Leakage management
Compressed air systems are the most effective and cost-effective to reduce emissions. Statistics show that the leakage of compressed air system is generally as high as 30~50%, and the factory or new factory with better management is about 10~30%. The proportion of this waste is extremely amazing.
If the faucets, lights, and air conditioners in your factory are not closed, someone must take care of them. Because it is a waste of water and electricity, it is easy to understand. However, compressed air leaks seem to be less serious, and it is not known that compressed air is produced by air compressors. Leaking compressed air is equivalent to wasting electricity. In other words, the governance leak is equal to the energy savings achieved by the air compressor system.
Air passage per minute at different pressures at different pressures
Compressed air leak data - air per minute per minute at a circular orifice at different pressures
A small hole with a diameter of 1 mm has a compressed air per pass through the small hole of 0.0742 m3 at a pressure of 7 bar. A simple calculation shows that in a year, compressed air leaking through a small hole with a diameter of 1 mm under a pressure of 7 bar will cost more than 4,000 yuan in electricity costs.
The possibility of leakage includes: insufficient connection and looseness of the pipe joint; the cylinder seal of the gas equipment is not strict; the air leakage or damage of the automatic drain port; the leakage of the solenoid valve and the filter device; the gas leakage of the gas source triple piece. The longer the leak exists, the more serious the leak will be.
There are dedicated instruments for finding leak points. In addition, conditions can be verified by the "holding test". After the production line is off duty, the pressure is kept at the usual working pressure, and the air compressor is turned off. The severity of the leak can be judged by observing the pressure drop rate. In a quieter environment (such as at night), it is easier to find leak points.
The above has a good effect on the leakage inspection of non-moving parts such as pipes and joints, but further inspections are required for components such as cylinders and valves.
02. Governance pressure loss
The pressure loss is the pressure drop. The air compressor exit 7bar to the use site is only 5bar, and the difference of 2bar is the pressure loss.
The economics of managing pressure loss are second only to governance leaks. For fluid transport, there is a pipe and the pressure loss must exist. For those products with superior design and superior technological materials, the pressure drop is usually small. Ideally, a large-sized seamless stainless steel straight pipe is used, but it cannot be ideally produced in actual production, and the price is considerable. What we have to do is to strike a balance between pressure drop and economy.
Why is the pressure drop to be effective and effective for energy saving in air compressor systems? This is because the air compressor consumes about 7% of power for every 1 bar of pressure. If the site requires 5 bar pressure, if the pressure loss is 2 bar, the air compressor outlet pressure needs to reach 7 bar or more. Assuming that the pressure loss can be reduced to 1 bar by the treatment, the outlet pressure of the air compressor can be adjusted down by 1 bar, which means that the air compressor will save about 7%, which is very impressive. (This is much more cost-effective than replacing a new air compressor).
Some pressure loss is caused by design selection, and some are acquired factors, such as construction process and lack of maintenance.
Some parts and causes that cause large pressure loss: 1 pipe is too long (non-annular pipe), small size, reduced diameter, short radius elbow, too many valves, rough inner welding of pipes, etc.; 2 filter, suction The dryer is under maintenance, non-full-diameter valve, and air source triple-piece pressure regulating device.
In addition to the inspection and transformation of the above parts, it is also necessary to pay attention to some practices of “regulating the steps”, such as non-essential centralized gas supply (air compressor station), deliberate pursuit of uniform models, and some gas equipment. The filter unit of the belt is very inefficient, and the inferior gas source triple piece is not necessary in addition to increasing the pressure loss.
03. Reduce gas pressure
Air compressor pressure of 1 bar requires about 7% of energy consumption. Therefore, the pressure set by the air compressor is directly related to the electricity cost of the air compressor.
Some misconceptions:
1 There are a lot of air compressor users holding a steady psychological, air compressor pressure setting is not high;
2 Reproduction of peer-to-peer production processes and equipment, including air compressor systems, is considered to be a mature experience, thus causing some erroneous operations of outdated technology to be repeatedly copied;
3 The gas source requirements of the gas equipment are not clear or the margin is too large, even after high pressure and pressure reduction, in order to "maintain pressure stability", these devices often do not pursue high efficiency, causing some unnecessary waste;
4 The air compressor pressure selection adopts “no high or low”, which leads to the high pressure required to meet the local high pressure use requirement of very small flow.
Solution:
The minimum pressure requirements for detailed nuclear utility equipment can be verified by experiments if conditions permit. If the pressure difference between the demand exceeds 1 kg, the high-pressure and low-pressure air compressor system can be considered for gas supply separately. Some small flow high pressures can be achieved with a booster valve without the need for global high pressure.
04. Adjust the running settings
There is a phenomenon, many air compressors that have been used for many years, and their operation settings are still factory settings when they are put into use.
For example, the pressure setting is not set according to the actual needs of the factory. Instead, it is set according to the specifications of the air compressor. For example, an air compressor of 0.8 MPa, the unloading pressure of the loading and unloading control method is 0.8 MPa, and the loading pressure is 0.7 MPa, even if Actually only 0.6 MPa is required, which is very common.
For example, the no-load time of the unloading control mode is changed by almost few people. No-load, that is, the air compressor no longer produces gas, but the motor is still running. Since there is no compressed air output, the power consumed at this time is useless.
The no-load time set by the manufacturer is to prevent the user from supporting the gas storage tank too small, resulting in frequent start-up damage to the air compressor. The setup time is relatively long, and some even last up to 30 minutes. This means that if the air compressor does not drop to the set loading pressure, the air compressor will continue to idle for 30 minutes before it stops. The energy consumption of the air compressor at no load is between 30% and 50%, which is a very serious waste.
The linkage setting problem of multiple air compressors, many companies set the uniform pressure, which will cause the loading and unloading almost at the same time (actually because the error of each pressure sensor is not the same, there is always a pressure value downward shifting) The air compressor is first started, and the one with the upward pressure value is first unloaded). The correct approach should be to split the base and auxiliary machines (the basic air compressor is responsible for the basic flow, and the auxiliary machine is responsible for the flow change adjustment).
The above is the details of the operation of the energy-saving scheme of the air compressor system that is shared for everyone without spending money and less money. Moreover, these methods can basically be implemented by the user and get good results.
