Double Energy-saving Principle Analysis
Before, we had two kinds of energy-saving refrigerated air dryers. One is the PD series compressor air dryer. It has a compact 3-in-1 plate heat exchanger. Large heat exchange areas can increase efficiency, thereby saving energy. Another is the VSD air dryer. Here this refrigerated air dryer for air compressor combines their advantages. So we will analyze why it saves energy from two aspects.
(1) Energy Saving From Low-pressure Loss/Drop
This dryer is also the shell-tube type. But there is still a big difference from the traditional refrigerant air dryer. Traditional dryers are generally double-pipe. Tuy nhiên, this refrigeration air dryer is a single tube. The heat exchange system is integrated. Structurally, the evaporator is in the middle. Surrounding the outside are the heat exchange tubes of the precooler.
The advantage of the integrated design is the ability to circulate compressed air during heat exchange. One-piece design reduces cornering links. So effectively reduces airflow resistance. The pressure drop of this refrigeration air dryer is less than 0.1 quán ba.
The number of aluminum tubes surrounding the outside is particularly large and densely distributed. When compressed air circulates inside, the heat exchange area is large. So the heat exchange efficiency is high. Đồng thời, it uses fewer deflectors than traditional refrigerated air dryers.
Here take an example to illustrate why the pressure drop is small. Demonstrate with LY-DB200DAH dryer. The air capacity of a refrigerated dryer for compressed air is 28.5m³/min. Compressed air pressure is 0.6~1.0MPa. The flow speed is 10-15m/s.
Here we choose a 12m/s flow rate. Select the pressure 0.7Mpa. Through the calculation formula of compressed air flow, we can get the inner diameter of the delivery tube to be 79mm. And we choose the DN80 tube. The sectional area of DN80 is 5153mm2.
As long as the flow cross-sectional area of each part of the heat exchange system is greater than 5153mm2, there will be no pressure loss.
The outer diameter of the pre-cooling tube is 10mm, and the inner diameter is 9 mm2. The quantity is 250 pieces. The flow cross-sectional area of a single tube is 63.6mm2. So the sum is 15900 mm2. 15900mm2 is greater than 5153mm2.
The flow cross-sectional area of the shell side of the heat exchanger assembly is 44579mm2. 44579mm2 is greater than 5153mm2.
The flow cross-sectional area of the shell of the heat exchanger assembly is 44579mm2. 44579mm2 is greater than 5153mm2.
Vì thế, there will be no pressure loss inside the heat exchanger assembly.
Energy-saving Analysis of Refrigerated Air Dryer:
Many air compressor stations have the problem of large pressure drops. This leads to the high energy consumption of air compressors. Through theoretical calculation and actual testing, we conclude that for every 1 kg increase in air compressor pressure, energy consumption increases by 5-6%. Trong cùng điều kiện làm việc, áp suất càng cao, the greater the gas consumption. This process is also a process of energy waste.
The pressure difference of traditional refrigerated air dryers is ≥ 0.4 quán ba. But this refrigeration dryer for compressed air is only less than 0.1 quán ba. It can save pressure loss by more than 0.3 bar than traditional dryers.
How Much Energy Can Be Saved By Low-pressure Loss?
Ví dụ, there is a 160KW air compressor. Power consumption increases by 5% for every 1 bar increase in pressure. Compared to the traditional refrigerant dryer, this dryer can save 0.3 quán ba. We calculated that the energy consumption of the air compressor can save more than 2%.
Then when the pressure difference of the refrigeration air dryer system is 0.4 quán ba, 160KW*2%=3.2KW. When the pressure difference of the dryer system is less than 0.1 quán ba, 160KW*0.5%= 0.8KW. By comparison, this refrigerated air dryer can save 2.4KW per hour.
Calculate it by 8000 giờ. It can save 2.4*8000 = 19200 KW. And calculate at 0.8 CNY per kWh. It can save 19200*0.8=15360 CNY.
(2) Energy Saving From VFD Refrigerant Compressor
This dryer is also the shell-tube type. But there is still a big difference from the traditional refrigerant air dryer. Traditional dryers are generally double-pipe. Tuy nhiên, this refrigeration air dryer is a single tube. The heat exchange system is integrated. Structurally, the evaporator is in the middle. Surrounding the outside are the heat exchange tubes of the precooler.
The advantage of the integrated design is the ability to circulate compressed air during heat exchange. One-piece design reduces cornering links. So effectively reduces airflow resistance. The pressure drop of this refrigeration air dryer is less than 0.1 quán ba.
The number of aluminum tubes surrounding the outside is particularly large and densely distributed. When compressed air circulates inside, the heat exchange area is large. So the heat exchange efficiency is high. Đồng thời, it uses fewer deflectors than traditional refrigerated air dryers.
Here take an example to illustrate why the pressure drop is small. Demonstrate with LY-DB200DAH dryer. The air capacity of a refrigerated dryer for compressed air is 28.5m³/min. Compressed air pressure is 0.6~1.0MPa. The flow speed is 10-15m/s.
Here we choose a 12m/s flow rate. Select the pressure 0.7Mpa. Through the calculation formula of compressed air flow, we can get the inner diameter of the delivery tube to be 79mm. And we choose the DN80 tube. The sectional area of DN80 is 5153mm2.
As long as the flow cross-sectional area of each part of the heat exchange system is greater than 5153mm2, there will be no pressure loss.
The outer diameter of the pre-cooling tube is 10mm, and the inner diameter is 9 mm2. The quantity is 250 pieces. The flow cross-sectional area of a single tube is 63.6mm2. So the sum is 15900 mm2. 15900mm2 is greater than 5153mm2.
This refrigeration dryer for compressed air uses a variable-speed compressor. It can adjust the refrigerant to adapt to changes in working conditions. Vì thế, this air compressor dryer is especially suitable for occasions where the working conditions change greatly. One case is that the temperature change is relatively large. Ví dụ, the temperature difference between morning and evening is large daily. Or there is a large temperature difference between the four grades throughout the year. Another situation is that the actual air consumption varies greatly.
How Does The VFD Compressor Bring Energy Saving?
The double-effect energy-saving air dryer can sense the change of evaporative load. Vì thế, the compressor frequency variation can be controlled.
Take the air-cooled refrigeration dryer as an example. When the ambient temperature decreases, the air compressor discharge temperature will decrease. The condenser temperature is also easier to cool down. So there will be a lot of room for energy saving. Ngoài ra, for example, summer will be hot for three months. Tại thời điểm này, the load of the refrigeration dryer for compressed air is higher. Vào mùa đông, the load on the refrigerated dryer is lower. Because in winter, the inlet temperature and ambient temperature are low. Tại thời điểm này, the refrigerant dryer’s working condition has improved. Then its energy-saving effect will come out. Because the refrigerated dryer no longer needs such a high cooling capacity. Đó là, the power of the refrigerant compressor does not need to be so high.
If it is a traditional refrigerated dryer, it cannot adapt to this change. It will run at rated power. But our dual energy-saving refrigeration dryer is different. It uses a VFD compressor. It can adjust the power to adapt to this change. When the actual air consumption changes, the principle of energy saving is similar.
Ví dụ, the compressor of the traditional 200Hp refrigerated air dryer is 5P. The input power is 4.32KW (Copeland compressor VR57KF). The cooling capacity of the compressor is 13.9 KW. The cooling capacity of the VFD compressor in the double energy-saving refrigeration dryer is 6.76KW~23.38KW. The corresponding input power is 2.03KW~7.06KW. It bases on the frequency of 30Hz ~90HZ.
In the case of the same cooling capacity, the corresponding input power of the VFD compressor is 3.068KW. Trong cùng điều kiện làm việc, the double energy-saving refrigeration air dryer can save energy by 29%.
Double Energy-saving Compressed Air Refrigerated Dryer Working Principle
High temperature compressed air enters from the dryer inlet (MỘT). Then flow down the precooler. Its flow rate is relatively fast. Their temp will preliminarily cool in the precooler. Then enter the evaporator through the opening. Đây, heat exchange is performed with the refrigerant. There will generate condensation water during this process. Tương tự như vậy, a separator separates air from moisture. Then liquid water will be drained out.
Mặt khác, cold compressed air enters the precooler again. They exchange heat with high-temperature air. After cooling down, dry compressed air is discharged from the outlet (b).
