Guangzhou Huangjinwei Warehouse Renovation Project

1、 Current situation of air conditioning and water system in logistics warehouse

The air conditioning system ensures that the temperature inside the Huangjinwei Pharmaceutical Warehouse is maintained within 20 ℃, playing a crucial role in the storage of valuable drugs.

The air conditioning system has 6 water pumps (30KW cooling water pump for dual use and one backup, 30KW chilled water pump for dual use and one backup), and 2 cooling tower fans (with a power of 4KW). 1-3 11KW fans (a total of 24 fans) are installed on each floor for air supply, all of which are currently operating in power frequency mode.

The water pump and fan operate directly at the power frequency, which has disadvantages such as high starting current, large mechanical shock, and poor electrical protection. Often, the water pump burns out, the motor burns out, and there is water leakage at the pipeline connection. This not only wastes energy but also accelerates equipment loss, resulting in high maintenance costs.

2、 User modification requirements

1. Add DDC system, which can set a constant temperature through the system and automatically control the start and stop of each cooling water pump, chilled water pump, cooling tower fan, and fan, as well as the on/off of each pipeline electric butterfly valve according to the set temperature;

2. The start and stop of cooling water pumps, chilled water pumps, cooling tower fans, and fans, as well as the on/off of electric butterfly valves in each pipeline, can also be switched to manual operation separately to ensure the operation of the system;

3. Reduce the workload of operating personnel, eliminating the need to manually start and stop each distribution box;

4. Simple operation, reliable operation, easy maintenance, and reasonable cost;

5. Realize energy conservation;

6. When the frequency converter malfunctions, it can be switched to the power frequency operation mode through the switch on the cabinet door, greatly ensuring the stable operation of the system;

3、 Control scheme, as shown in the figure1、2、3、4.

image1

image2

image3

image4

4renovation effect

1. The on-site renovation construction requires a small amount of work, only replacing damaged pipelines and electric butterfly valves;

2. The distribution box is installed near the old distribution box, and only needs to be rewired from the old distribution line to within 10 meters of the new distribution box;

3. Easy to operate and maintain, operators only need to operate the selection switch, button, and potentiometer of the cabinet door to achieve manual operation mode. Through DDC, the system can achieve fully automatic operation by setting a constant temperature and selecting start on the PC, making it convenient and flexible to switch between manual and automatic operation modes;

4. The Danfoss frequency converter has complete protection functions and can provide multiple protections for the motor, such as overcurrent, phase loss, short circuit, grounding, etc; After adopting frequency conversion control, the mechanical impact of the system disappeared and the water hammer phenomenon disappeared;

5. The system runs reliably. When the frequency converter fails, it can be switched to the power frequency operation mode through the cabinet door switch to ensure uninterrupted and reliable operation of the system;

6. Energy saving, the built-in PID function of Danfoss frequency converter can automatically adjust the output frequency according to water pressure, which can achieve energy saving;

Equipment isAt the end of May 2017, it was officially handed over to the customer, and the system is running stably with significant energy-saving effects.