Joint control of air compressor and chilled water dryer

The joint control system of air compressors and chilled water dryers is widely used in modern industries. Its core lies in achieving efficient production and purification of compressed air through intelligent control. The following is an analysis from four aspects: purpose, technical advantages, implementation methods and actual cases:

1. Core goals and advantages of joint control

1. Improve the quality of compressed air
   The compressed air output by the air compressor contains a large amount of water vapor, oil and impurities. The chilled water dryer condenses water vapor into liquid water by cooling and discharges it, ensuring that the compressed air dew point temperature is as low as 2-10℃ (pressure dew point) to prevent downstream equipment from being corroded or condensed due to moisture.

2. extend equipment life
   Dry air reduces oxidation and wear on pipes and pneumatic components. For example, in the food packaging industry, dry air prevents cylinder and piston jams due to rust, reducing the equipment failure rate by more than 40%.

3. Energy conservation and cost optimization
   The joint control system automatically adjusts the start and stop of the air compressor and the load of the dryer according to the air consumption. For example, after an electronics factory was transformed through joint control, it saved annual electricity bills by about 180,000 yuan and reduced equipment maintenance costs by 35%.

2. Technical realization method of joint control

1. Hardware integrated architecture
   • parallel mode: Multiple air compressors + dryers are connected in parallel, suitable for large flow needs (such as steel mills), but a single failure affects the overall situation.
   • Series mode: The air compressor and dryer are connected in series one by one to improve system stability (such as hospital air supply), but the pressure loss is large.
   • Hybrid model: Combined with the first two, the main circuits are connected in parallel to ensure flow, and the backup circuits are connected in series to ensure redundancy.
2. intelligent control system
   • sensor network: Deploy temperature and humidity sensors and pressure sensors at the outlet of the air compressor and the inlet and outlet of the dryer to feed back data in real time.
   • control logic：
     • When the compressed air temperature is greater than the ambient temperature +5 ℃, the dryer is automatically started;
     • When the pressure dew point is greater than the set threshold, an alarm is triggered and the standby dryer is linked.
   • communication protocol: Modbus or Ethernet/IP protocol is used to realize data interoperability between air compressor and dryer.
3. Energy saving optimization strategy
   • waste heat recovery: Use air compressor cooling water to preheat the inlet air of the dryer to improve refrigeration efficiency.
   • frequency conversion adjustment: Dynamically adjust the speed of the air compressor according to the air consumption to match the dryer load.

3. Typical application scenarios and cases

1. precision manufacturing industry
   • case: An auto parts factory uses a joint control system of 3 screw air compressors +2 chilled water dryers.
   • effect: The dew point of compressed air on the spraying line is stable at-15℃, and the paint defect rate is reduced from 1.2% to 0.3%.
2. Pharmaceutical and Food Industry
   • case: Pharmaceutical companies adopt the structure of double air compressors in series + double dryers in parallel.
   • effect: The oil content of compressed air in the sterile workshop is <0.01ppm, which meets GMP standards.
3. energy industry
   • case: The natural gas field adopts a remote joint control system, integrating 5 air compressors +3 dryers.
   • effect: Achieve unmanned duty and save approximately 650,000 yuan in annual operation and maintenance costs.

4. Selection and maintenance suggestions

1. Equipment selection principles
   • flow matching: The processing capacity of the dryer must be ≥ 1.2 times the exhaust capacity of the air compressor.
   • pressure adapt: The pressure bearing capacity of the dryer must be ≥ the maximum system pressure +0.2MPa.
2. Maintain key points
   • Regularly calibrate sensors: Calibrate the pressure dew point sensor quarterly (error should be <±1℃).
   • condensate drain: Check the automatic drain every day to prevent secondary dew condensation.
   • energy efficiency test: Conduct energy efficiency tests of the joint control system every year to compare the energy saving effects before and after the transformation.

conclusion: Through intelligent integration, the joint control system of air compressor and chilled water dryer significantly improves the quality of compressed air and reduces operation and maintenance costs. In practical applications, the hardware architecture needs to be selected according to industry characteristics and combined with regular maintenance to ensure stable operation of the system.