AKD already has many customers in the global supermarket industry. Since 2007, nearly 10 supermarkets in China have also used AKD. After more than two years of efforts by Danfoss, AKD's application in China's supermarket condenser fans is becoming more and more mature. Theoretical analysis and multiple measurements have proved the energy-saving and optimization effects of AKD. This article will help more customers realize that there is a huge potential for energy savings on condensing fans.
1. Make full use of the heat transfer area of the condenser and greatly increase the efficiency of heat dissipation In the traditional control mode, the condenser fan is started in stages according to the condensing pressure. For example, eight 1kW fans are divided into four groups. In many cases, only two to six fans are in operation. This corresponds to only 25% to 75% of the condenser surface area being utilized. Moreover, the circulation will bring the heat of the condenser back to the part where the fan does not rotate. Therefore, under the traditional control mode, the heat exchange efficiency is often very low.
After using the AKD, all fans are adjusted together and the condenser surface area is 100% utilized. So you can achieve better heat dissipation with less energy.
For fan-type loads, the flow is proportional to the speed, and the energy consumption is proportional to the third power of the speed. In other words, all eight fans are operated at 25Hz with AKD, and only 1 degree is consumed in one hour. In the traditional way, two fans running at full speed will consume 4 degrees.
To illustrate the energy-saving effect, let's assume that the refrigeration system has been operating in this static condition. In one year, it will only save 4 degrees * 24 hours * 365 days, or 26,280,000 degrees on the fan.
2. Control of condensing pressure to further optimize unit operation The energy consumption of the refrigeration system is mainly in the compressor and condenser. The sum of the energy consumption of the two has the best advantage.
Danfoss' refrigeration controllers with condensing pressure float control, in conjunction with AKD, will allow the refrigeration system to operate near the best point. The traditional control mode is often run at a point where the compressor consumes a lot of energy. The AKD102 is Danfoss' dedicated frequency converter for the cooling system and contains condensation control. This means that customers do not need to add an extra expensive unit controller to fully realize the huge energy savings brought about by the condensing pressure floating control.
3. Significantly reduce the start-stop of the condensing fan Under the traditional control mode, the condensing fan starts and stops thousands of times per day, and the straight-up current of the motor is 5~7 times of the rated current. This not only increases energy consumption but also causes electrical and mechanical shocks. The measured results show that after the use of AKD, the number of fan start-stops was reduced by 30 to 50%. In most cases, the cooling requirements can be matched by adjusting the speed. At night or at low loads, the fan is also started at low frequency and the starting current is very small.
4. Other benefits to customers AKD can also significantly reduce the noise pollution of the condenser fan, reduce the accumulation of dust on the condenser surface, and reduce the flash phenomenon.
Conclusion
The application of AKD condenser fan brings very obvious energy saving and system optimization results to supermarket customers. As the world's leading refrigeration system control manufacturer, Danfoss has taken the lead in promoting the frequency conversion speed regulation technology in domestic supermarkets. It is believed that AKD will gain more customers' favor and make its due contribution to the energy conservation and emission reduction of Chinese supermarkets.
