Several large unit systems of screw air compressors (cooling / oil / control system)
Several large unit systems of screw air compressors (cooling / oil / control system)
Cooling system
2. Oil and gas separation system
3. Control system
4. Accessories for silencer, shock absorption, ventilation, etc.
cooling system
Air compressor cooling methods are air-cooled and water-cooled. Air-cooled and water-cooled are not good or bad, only applicable and not applicable.
◆ Water cooling requires the owner's enterprise to have a cooling water system, and the air cooling is more flexible, but there are also requirements for good ventilation in the installation site;
◆ The cooling effect of the water-cooled model is completely dependent on the cooling water system. If the cooling water system of the owner's enterprise is operating normally, the cooling effect is very stable and reliable. Air cooling is greatly affected by the ambient temperature and the installation environment, but usually the manufacturing company has already considered the extreme situation when designing, so it can achieve satisfactory cooling effect when installed according to requirements.
◆The water-cooled air compressor does not need electricity equipment during the cooling process, and does not occupy the energy consumption of the air compressor itself (the circulating cooling water of the owner's enterprise needs electricity to be another). The air-cooled air compressor needs to be equipped with a cooling fan, which occupies the energy consumption of the air compressor body.
◆Water-cooling heat exchange efficiency is high, the volume is small, and it is more compact and compact than the air-cooled structure. In addition, due to the air-cooling cooling fan, the wind noise is large during operation, so the noise value of the water-cooled air-cooled machine is low.
The medium to be cooled by the air compressor is compressed air, and the other is cooling oil (or air compressor oil, lubricating oil, and coolant). The latter is the most critical. It is the continuous operation of the whole unit. The key is.
The air compressor oil needs to be infinitely circulated in the body, which acts as a heat porter, bringing the heat and other heat released by the compression of the air during the compression process to the cooler, and is carried away by the cold medium (wind or water). .
In engineering, air-cooled air compressors almost all use plate-fin coolers, usually air-cooled and oil-cooled into one, and a part of cooling compressed air (air-cooled) partially cools the air compressor oil (oil-cooled). The water-cooled ones are almost all shell-and-tube type (or tube-type), oil-cooled coolers and air-cooled coolers.
The air-cooled plate-fin cooler is brazed from aluminum or aluminum alloy. The high-temperature oil and compressed air flow in the cooler, and the heat is forced by the cooling fan to take away the heat.
Water-cooled shell-and-tube type (column tube type) cooler, the heat medium is high temperature oil and compressed air, and the cold medium is cooling circulating water. The heat is taken away by the cooling water by heat exchange.
Oil and gas separation system
When the fuel injection screw air compressor compresses the air during the compression process, there must be a system to separate the oil and the gas, and leave the oil in the machine to continue to recycle and discharge the pure compressed air. The role of the oil and gas separation system is here.
It is the separation efficiency of the oil and gas separation system that reaches an acceptable level, and the injection screw model is widely used.
The oil and gas separation system of the air compressor is mainly composed of an oil storage tank and an oil separator.
Workflow: The oil and gas mixture from the exhaust port of the main engine enters the space of the oil separation tank. Most of the oil collects in the lower part of the tank through air collision and gravity, and then enters the oil cooler for cooling. The compressed air containing a small amount of lubricating oil is passed through the fine oil separator core to fully recover the lubricating oil, and flows into the low pressure portion of the main unit through the throttle check valve.
Control System
The air compressor control system includes logic controllers, various sensors, electronic control sections, and other control components. The image says that the air compressor control system is the brain, cerebellum, neural network, muscle tendon, etc. The air compressor without control system is just a bunch of components.
There are basically two types of controllers for screw machines (there are almost no pure instruments): a single-chip microcomputer, a PLC. The former is generally produced by a special air compressor controller factory to meet the general requirements of air compressor control, and the logic program cannot be changed. PLC (Programmable Controller) is a general-purpose industrial controller that needs to be self-programmed to realize the function of air compressor control, and also to meet the unique control requirements of its own products (for air compressor manufacturers).
The sensors used in the air compressor are mainly pressure and temperature sensors, and of course some parts will use differential pressure switches.
The electric control of the motor is the main part of the air compressor control. In simple terms, the control of the air compressor unit is realized by the on/off operation of the motor. Including various AC contactors, circuit breakers, transformers, relays, etc., the electronic control part of the main motor is generally referred to as the "starting disk".
The application of frequency conversion technology in the industry is more and more extensive, which is outside the control of the start and stop of the motor, and another control purpose: the control of the motor speed. This part is completed by the frequency converter or the embedded frequency conversion component. Usually, the start/stop of the air pressure electric control part using the frequency conversion is also controlled by the frequency converter, unless it is the air compressor of the industrial/frequency conversion dual system.
In addition to electrical control, there are many mechanical controls on the air compressor, such as temperature control valves and minimum pressure valves.
Accessories for silencer, shock absorption, ventilation, etc.
In the oil-injected screw air compressor unit, there are also some functional accessories, mostly in standard configuration:
On the inner wall of the air compressor case, sound-absorbing cotton is attached to absorb the high-frequency noise of the air compressor.
A rubber cushion is arranged at a position where vibration, such as a motor, a main engine, an oil and gas drum, etc., may occur.
On a slightly larger model, in addition to the cooling system, a ventilation fan is generally provided for heat dissipation inside the chassis.
Gas-water separators, installed on air-cooled or air-cooled systems on slightly larger models.
