As a key piece of equipment in high-efficiency data centers, the performance of chillers plays a crucial role in the overall performance and energy efficiency of these centers. Therefore, the performance and selection of chillers are of paramount importance.
During the selection phase, it is necessary to utilize selection software to analyze and compare the chiller's performance under a thousand operating conditions (i.e., the cooling capacity and input power of the chiller under various load rates, chilled water outlet temperature and temperature difference, cooling water return temperature and temperature difference, and chilled water and cooling water flow rates). This allows for the construction of a full-condition performance model of the chiller. On the one hand, this model can calculate the hourly energy consumption of the chiller over 8760 hours during the energy efficiency simulation phase to predict the system's overall annual energy efficiency. On the other hand, during operation, the control system can match the current operating parameters with the operating database to find the optimal operating point of the chiller in real time. Therefore, the thousand-point operating condition selection analysis of the chiller plays a crucial role in energy efficiency prediction and proactive optimization control.
In addition, when selecting chiller units, factors such as the similarity of water resistance between the two chillers in parallel units must be considered, which will not be elaborated here. This discussion on the selection of high-efficiency computer room chiller units only focuses on conventional air conditioning systems and chiller units, and does not cover heat recovery, ice storage, water storage, natural cooling, or other operating conditions.
How to choose the most suitable industrial chiller? It's actually quite simple; there's a selection formula: Cooling capacity = Chilled water flow rate * 4.187 * Temperature difference * Coefficient
1. Chilled water flow rate refers to the required chilled water flow rate when the machine is operating; the unit needs to be converted to liters per second.
2. Temperature difference refers to the temperature difference between the inlet and outlet water of the machine.
3. 4.187 is a fixed value (specific heat capacity of water).
4. When selecting an air-cooled chiller, multiply by a coefficient of 1.3; when selecting a water-cooled chiller, multiply by a coefficient of 1.1.
5. Select the appropriate machine model based on the calculated cooling capacity.
The common practice is to use "P" to calculate the required size of a chiller, but the most important thing is to know the rated cooling capacity. Generally, a 9.07KW air-cooled chiller would be a 3P machine, and so on. Therefore, the most important thing in selecting an industrial chiller is to determine its rated cooling capacity.
