What are the reasons for poor oil return of the screw machine in the HVAC system
A screw compressor is a common type of compressor used to compress gases, usually air or gas mixtures, to higher pressures. It utilizes the rotation of the screw to realize the compression process of the gas.
A screw machine usually consists of two screws (a pair of screws), which are a male screw and a female screw. The axes of the male and female screws are parallel and they rotate inside the compressor casing to form a closed compression chamber. When the screw rotates, the gas is sucked into the compression chamber, and with the rotation of the screw, the gas is compressed and pushed to the outlet, so as to achieve the purpose of gas compression. Screw machines have some advantages over other types of compressors, such as simple structure, smooth operation, and high efficiency.
Advantages: High efficiency: The screw machine has an efficient gas compression capacity and is able to compress the gas to the required pressure level in a shorter time.
Stable operation: The structure of the screw machine is simple, there are no valves and other moving parts, so the operation is stable and the noise is low.
High flow rate: The screw machine is capable of handling large gas flows, making it suitable for large industrial systems.
Long life: Screw machines are relatively simple in structure, usually have a long service life, and they can run for a long time as long as they are properly maintained.
Energy saving: Screw machines are generally more energy efficient than reciprocating compressors under the same operating conditions, as there is no loss of intermittent compression of the cylinders.
Disadvantages: Higher initial cost: Screw machines have a higher initial purchase cost compared to some other types of compressors.
Complex maintenance: Although the structure of a screw machine is relatively simple, maintenance may require specific skills and knowledge, requiring regular inspection and maintenance.
Not suitable for high pressure: The efficiency of the screw machine may be reduced at higher pressure conditions and it is not suitable for some specific high pressure applications.
Need for clean gas: The screw machine has high requirements for the purity of the gas, and is not suitable for gases containing a large number of particles or pollutants.
The impact of poor oil return of the screw compressor.
The screw compressor has poor oil return, which will lead to a large amount of lubricating oil trapped in the evaporator pipeline, when the oil film increases by 01mm will directly affect the cooling of the system, on the other hand, the machine can not run due to lack of oil, and needs to constantly replenish the lubricating oil, which will lead to the accumulation of lubricating oil in the system, resulting in a vicious circle, increasing operating costs and reducing operational reliability.
There can be a variety of reasons for poor oil return in a screw machine, and some of the common possible reasons are listed below:
Oil quality: The use of inferior or contaminated lubricating oil may result in poor oil return in the screw machine. The oil should be clean and free of impurities or moisture.
Oil viscosity: The viscosity of the oil should be suitable for the working temperature and pressure conditions of the screw machine. A viscosity that is too high or too low can lead to poor oil return.
Oil temperature: High oil temperature may cause the oil to be thin, which will affect the lubrication effect, and may also lead to oil vaporization, which will affect the oil return.
Clogged return lines: Dirt, impurities, or other obstructions in the return lines can cause unsmooth oil returns.
Return Pump Problems: If the return pump is faulty or not working properly, it will lead to poor oil return.
Compression screw problems: Wear, corrosion, or damage to the screw inside the screw machine can also affect oil return.
Overload: When the screw machine is overloaded, insufficient oil return is one of the common problems.
Lubrication system failure: Failure or improper operation of the lubrication system can also lead to poor oil return.
Improper design of the lubrication system: The improper design of the lubrication system may lead to poor oil return or poor lubrication effect.
To solve the problem of poor oil return of the screw machine, it is first necessary to carefully inspect and diagnose to find out the specific cause.
Then, depending on the nature of the problem, repairs, replacement parts, or adjustments to operating parameters are carried out accordingly. Regular care and maintenance of the screw machine and its lubrication system is also key to keeping it working properly.