The Role and Selection of Surge Tank for Recirculation System

 
In modern recirculation systems, the role of surge tanks is indispensable. They enhance system stability and operational efficiency by storing and regulating water flow, thus balancing load fluctuations. Properly selected surge tanks not only reduce the frequent start-stop cycles of equipment, extending their service life, but also decrease energy consumption and maintenance costs. However, the selection process involves multiple key factors, making the choice of an appropriate surge tank crucial. Below is a detailed analysis of the role of surge tanks and practical advice for selection.

The Function and Advantages of Surge Tanks

 
Surge tanks play a vital role in recirculation systems, primarily by storing and regulating water flow to improve system stability and efficiency. Here are the main functions and advantages of surge tanks.

1. Reduction of Frequent Start-Stop Cycles

 
Surge tanks can store hot or cold water, effectively mitigating temperature fluctuations in the recirculation system. When the water temperature reaches the set target, the stored water in the surge tank can continue to supply the system, thereby reducing the frequent start-stop cycles of the compressor. This approach not only extends the service life of the compressor but also effectively reduces electrical energy consumption and improves the stability of the system's operation.

2. Gas Exclusion

 
The design of surge tanks typically allows circulating water to enter from the top of the tank and exit from the bottom. This design enables the accumulation of gases within the tank, which are then expelled through an automatic air vent valve. This not only prevents the impact of gases on the system but also protects the impeller of the pump from damage by bubbles, ensuring the normal operation of the compressor.

3. Prevention of Impurity Accumulation

 
Impurities in the water source may gradually deposit at the bottom of the surge tank during the system's circulation. Without a surge tank, impurities could adhere to the internal pipes of the chiller, leading to abnormal cooling effects or equipment damage. Surge tanks effectively prevent the accumulation of impurities inside the equipment, enhancing the stability and operational efficiency of the cooling system.

4. Reduction of Pressure Fluctuations

 
Surge tanks can alleviate pressure fluctuations in the system, maintaining stable system pressure, thereby reducing the pressure impact on pipes and equipment. A stable pressure environment helps to reduce wear and tear on pipes and equipment, improving the system's operational reliability.
 

Selection Advice for Surge Tanks

 
Choosing the right surge tank is crucial for improving system operational efficiency, extending equipment life, and reducing maintenance costs. Here are some key selection tips to help you choose the most suitable surge tank based on actual needs.

1. Choice of Insulation Layer

 
The thickness of the insulation layer is crucial for the insulation effect of the surge tank. In warmer winter regions, it is recommended that the insulation layer be 40-50mm thick to effectively prevent heat loss. In colder winter regions, the insulation layer thickness should be increased to 80-100mm to adapt to lower temperature environments. In addition, the density of the insulation layer is also a key factor. Insulation materials with higher density offer better insulation effects. Choosing uniform foam materials ensures good insulation performance.

2. Positions of Outlet and Return Inlets

 
Outlet: It should be about 30 cm from the bottom of the tank. This design prevents sediment from being sucked into the pump filter, reducing the pump's load and maintenance costs. Maintaining an appropriate outlet height prevents bottom sediment from affecting the system.
 
Return Inlet: It should be about 20 cm from the top of the tank. This prevents water overflow or splashing when the return water flow is high. For non-pressurized tanks, correctly setting the return inlet position is particularly important, while for pressurized tanks, this requirement is relatively more relaxed, but it is still necessary to ensure that an air vent valve is equipped.

3. Position of Temperature Sensors

 
The installation position of the temperature sensor probe should be chosen about 2/3 of the way from the bottom of the tank. This is because hot water is usually concentrated in the upper layer, and the probe measuring the water temperature at this position will be more accurate, helping to achieve more reliable temperature control.

4. Insulation and Support Structure at the Bottom

 
The bottom of the surge tank needs to have an insulation layer, and steel supports should be added on both sides. This is to prevent the deformation of the bottom insulation layer due to the gravitational force when the tank is full of water, thereby ensuring the stability of the insulation effect and the overall structural strength of the tank.
 
By properly designing and selecting surge tanks, you can significantly improve the operational efficiency of the recirculation loop, reduce the frequent start-stop cycles of equipment, lower electrical energy consumption, and ensure the stability and long life of the system. Meticulous selection and installation measures, such as the thickness of the insulation layer, the positions of the outlet and return inlets, the setting of temperature sensors, and the bottom support structure, are key factors in ensuring the optimal performance of the surge tank. These measures not only enhance the overall operational efficiency of the system but also provide strong support for long-term stable operation.