Last week we received an invitation from a customer to visit their plant and develop a cooling program for their machine. There are about a dozen die casting machines in production.

We were guided by our client to visit their factory environment and production process. 

Finally, we summarized the customer’s needs and production environment to recommend a 80hp water-cooled screw machine. After about 7 working days of production, our 80hp water-cooled screw machine is finally ready.

So, compared with other types of water chillers, what are the performance, cost-effectiveness, advantages and disadvantages of water-cooled screw machines? Let’s take a look together.

Performance
1. High efficiency: The cooling efficiency of water-cooled screw machines is generally higher, because the thermal conductivity of water is stronger than that of air, so water-cooled systems have better heat transfer efficiency than air-cooled systems. Screw compressors perform particularly well under medium to large loads and have good performance regulation.

2. Adaptation to large-scale loads: screw compressors can be adjusted in a wide range of refrigeration capacity, suitable for industrial, commercial and other large-scale places of cooling needs, especially in large refrigeration capacity scenarios (such as plastics manufacturing, food processing, chemical industry, etc.).

3. Stable: water-cooled screw machines are more stable in performance over long periods of time, making them suitable for industrial applications that run continuously for 24 hours. Screw compressors, due to their structural characteristics, less vibration, relatively low noise, and smooth operation.

4. long life: screw compressor design is simple, less moving parts, low friction, so under reasonable maintenance its life is usually longer.

Cost effectiveness
1. Higher initial investment: the initial investment of water-cooled screw chillers is relatively large, with high equipment costs and complex installation. In particular, the need for supporting cooling towers, pumps and other auxiliary facilities, the overall cost of the system.

2. Low operating costs: Despite the high initial cost, the water-cooled system in long-term operation of the energy efficiency ratio (COP) is generally higher, especially in the case of high load and long-term continuous operation, its energy consumption is relatively low. Therefore, in the long run, water-cooled screw machines are more cost-effective in terms of operating and maintenance costs.

3. Moderate maintenance cost: Although the maintenance cost of water-cooled screw machine is higher (regular cleaning of condenser, checking water quality, etc.), compared with other types of water chillers, it is stable in operation and has a low failure rate of the equipment, which reduces the indirect cost due to downtime for maintenance.

Advantages
1. energy saving and high efficiency: water-cooled system utilizes water for cooling, with high energy efficiency ratio, especially under large-scale cooling load, it can significantly save energy consumption and reduce operating costs.

2. Stable operation: Screw compressor compresses the gas gradually, which reduces the instantaneous impact, low vibration and stable operation. It is suitable for large-scale factories or equipments that need to work continuously.

3. low noise: compared with reciprocating compressors, screw compressors are lower noise, suitable for applications that require a quiet environment.

4. long life: screw compressors usually have a longer life than other types of compressors due to fewer moving parts and less wear and tear.

5. Suitable for large-scale refrigeration: Suitable for medium and large enterprises with high cooling demand, especially in the continuous work of large industrial scenarios, the screw chiller is more advantageous.

6. Good environmental adaptability: Due to the presence of water-cooled condensers, water-cooled screw chillers are less affected by ambient temperatures and are suitable for high temperatures or harsh environments.

Disadvantages
1. High initial investment: compared with air-cooled chillers, water-cooled screw chillers have high purchase and installation costs because of the need for ancillary facilities (e.g., cooling towers, piping systems, etc.), which require more space for installation. 2.

2. Complicated maintenance: Water-cooled systems require regular cleaning and maintenance of the condenser to prevent scale and other impurities from accumulating and affecting heat transfer efficiency. In addition, it is also necessary to maintain the quality of cooling water to avoid corrosion and clogging.

3. Dependence on water: Water-cooled systems require a continuous supply of water and have high water quality requirements. Especially in areas where water is scarce or of poor quality, the use of water-cooled systems may not be appropriate.

4. Low dependence on ambient temperature but limited by water temperature: Although water-cooled systems are not significantly affected by air temperature, variations in water temperature can have an effect on the efficiency of the system. If the water source is too hot, the condenser’s heat transfer capacity will be limited.

Comparison with other types of chillers
1. Air-cooled chiller:

  Performance comparison: air-cooled type is suitable for small and medium-sized load and ambient temperature is not high scene, subject to the ambient temperature. Water-cooled screw chillers are more efficient and suitable for large-scale and continuous production scenarios.

 Cost comparison: air-cooled initial installation costs are lower, but the long-term operation of energy consumption is higher, while the water-cooled screw machine initial investment is large, but the operating costs are lower.

2. Centrifugal chiller:

    Performance comparison: centrifugal chillers are usually used for super-sized cooling needs (e.g. commercial buildings, airports, etc.) and have higher efficiency and cooling capacity than screw machines, but are not as well regulated as screw machines, especially in small and medium-sized loads where the efficiency is not good.

   Cost comparison: centrifugal machines are more costly and complicated to maintain, and are suitable for super-large-scale application scenarios, while water-cooled screw machines are suitable for medium- and large-scale industrial use and are more cost-effective.

In summary, water-cooled screw chillers have excellent performance in large-scale and high-load refrigeration applications, with high energy efficiency and stable operation, especially suitable for industrial settings requiring long-term continuous operation. Although the initial investment is large, it is cost-effective in the long run due to its low energy consumption and maintenance frequency. Water-cooled screw chillers are an ideal choice for companies with high requirements for cooling capacity, long-term operating costs and operational stability.

If you are also looking for a screw machine that suits your needs, please feel free to consult us and our chiller experts will reply you within 24 hours. (thaconmachinery@gmail.com)