1、 Summary
The air-cooled water chiller refrigeration unit is suitable for medium and small systems where water resources are tight in the region; The longer the annual operating hours of the refrigeration system, the more advantageous it is to use air-cooled chiller refrigeration units; The annual comprehensive cost of air-cooled water chiller refrigeration units is lower than that of water cooled water chiller systems. However, if the water cooled water chiller system is properly managed and the water replenishment amount is controlled below 3%, it is difficult to recover the increased initial investment of air-cooled water chiller refrigeration units compared to water cooled water chiller refrigeration units.
2、 Technical and Economic Comparison between Air Cooled Chiller and Water Cooled Chiller Refrigeration Units
1. Description Considering that there are too many air-cooled condensers in large refrigeration units, it is often difficult to arrange them. On the other hand, too small water cooled refrigeration units are also not conducive to use. Therefore, a comparison is made between a moderately easy air-cooled water chiller refrigeration unit and a water cooled water chiller refrigeration unit with the same cooling capacity.
2. Initial investment of the unit
The initial investment of the unit includes equipment costs, installation costs, and electricity capacity increase costs; A comparison is made between a certain type of water cooled chiller refrigeration unit and an air cooled chiller refrigeration unit with the same host and evaporator. The annual operating time of the compressor ranges from 1000 hours to 3000 hours, while the annual operating time of the cooling tower and water pump ranges from 1400 hours to 4200 hours.
Operating cost of air-cooled water chiller refrigerating unit Annual power consumption cost of air-cooled water chiller refrigerating unit=(compressor power consumption+fan power consumption) × Operating time/year × Electricity price
Operating cost of water cooled chiller refrigerating unit Annual water cost of water cooled refrigerating unit=(total circulating water × Number of water changes+water replenishment × Total circulating water volume × Operating time/year) × Water price
Annual power consumption cost of water cooled chiller refrigeration unit=(compressor power consumption+cooling tower fan power consumption+cooling water pump power consumption) × Operating time/year × Electricity price
3、 Conclusion
The initial investment of air-cooled water chiller refrigeration units is relatively high, and the power consumption per unit of refrigeration capacity is also slightly higher than that of water cooled water chiller units. However, the annual comprehensive cost of air-cooled water chiller units is basically the same as that of water cooled water chiller units and slightly lower. The technical and economic analysis results show that it is reasonable to configure air-cooled condensers for small and medium-sized water chillers.
The longer the annual operation time of the water chiller, the more advantageous it is for the air cooled unit. Compared to the water cooled water chiller unit, the initial investment recovery period of the air cooled water chiller unit is shorter. Therefore, air cooled units are more suitable for chillers used for air conditioning in southern regions. From the perspective of cooling conditions, high wet bulb temperatures in southern regions are also detrimental to water cooled units.
The amount of cooling water make-up for a water cooled chiller unit is an important factor affecting its cost. Strengthening maintenance management and reducing water consumption are important aspects of reducing the cost of water cooled units.