Water-cooled Centrifugal Chiller

What Is A Water-Cooled Centrifugal Chiller

Centrifugal water chillers are key components of HVAC systems. It can cool the places and equipment you need. You rely on it to compress the circulating cooling water with steam and help the indoor circulating air remove heat. The heat absorbed by the chilled water, along with the heat generated by the compressor’s operation, will all enter the water circulation loop together. Finally, this heat is discharged into the atmosphere.

Key Components of Water-Cooled Centrifugal Chillers

Evaporator

There is a low-temperature and low-pressure liquid refrigerant in the evaporator. The refrigerant absorbs the heat of the equipment you need to cool and turns into a gas, but the temperature remains unchanged at this time. The equipment releases heat for cooling.

Compressor

The compressor sucks in the refrigerant and compresses it to make it high-temperature and high-pressure.

Condenser

High-temperature and high-pressure gas enters the condenser. The refrigerant gas releases heat and turns into a liquid. The chilled water absorbs the heat. This way, one cooling cycle comes to an end.

Expansion Valve

This is a pressure-reducing device. When the refrigerant goes in, it will become low-temperature and low-pressure.

Evaporator

The refrigerant returns to the evaporator again. Return to step one to complete the repeated cycle work.

What Are The Advantages of Centrifugal Chillers

Runs Stably

The heart of a centrifugal water-cooled machine unit lies in the impeller and the motor. The main work is done by the high-speed rotating impeller, compressing the refrigerant. There is no reciprocating motion of a piston machine, nor the multi-stage gear meshing of a screw machine.

Without these easily worn parts, the machine rotates more smoothly, and the vibration and noise are naturally reduced.

Easy to Maintain

Centrifugal water chillers have few moving parts, directly eliminating the trouble of maintenance. On a daily basis, only the oil filter, electrical wiring, and refrigerant pressure need to be checked.

Durable

The impellers of centrifugal water-cooled chiller compressors are mostly made of high-strength alloys. The motor heat dissipation structure has been optimized, and even the casing has been thickened to resist deformation. In addition, the force is evenly distributed during operation, and its service life is very long.

Does Not Make up Space

The centrifugal water-cooled machine features an integrated structure design, with the compressor, heat exchanger, and control system all integrated within a single frame. If your site area is limited, a centrifugal water chiller is a good choice.

Large Cooling Capacity

The principle of centrifugal compression is inherently suitable for large cooling capacities. Under the same power, its cooling capacity per hour can be 20% to 30% more than that of a screw compressor.

What Refrigerant Is used in Centrifugal Chillers

The mainstream refrigerants used in centrifugal water-cooled machines are HFC and HFO. HFCS, like R-134a, has been in use for a long time. HFO, such as R-1234ze, represents a new direction.

• Safety: The refrigerant needs to be non-flammable or low-flammable. These two types of refrigerants are either non-flammable (most HFCs) or low-flammable (some HFOs). You can use them with confidence.
• Environmental friendliness: Refrigerants also need to follow the national call for environmental protection. HFCS are gradually being restricted, while Hfos, due to their low GWP value (small potential for global warming), have become the preferred choice for upgrades. If you want to promote environmental friendliness, HFO is more suitable.

How Much Does A 1000-ton Centrifugal Chiller Cost

A 1,000-ton centrifugal chiller costs about $250,000 or more.

The cost of high-pressure centrifugal chillers is higher than that of low-pressure chillers. However, equipping a low-pressure chiller requires more power distribution equipment. In the long run, it is more cost-effective to be equipped with a high-pressure centrifugal water chiller.

Some Tips for Improving the Efficiency of Centrifugal Water Chillers

Regular Staff Training

Formulate operation manuals and maintenance manuals for employees. Regularly train employees.

Multi-unit Collaborative Control

Use multiple centrifugal water chillers to operate in coordination. For small loads, use low-power chiller units; for large loads, use high-power chiller units.

Maintenance of the Automatic Exhaust Device

Regularly inspect the scheduling device. If the exhaust device malfunctions, the automatic exhaust program can be initiated.

Upgrade of frequency conversion technology

Installing a frequency conversion drive on a centrifugal chiller can enhance the operational efficiency of the water side.

Economizer Is Activated

When the ambient temperature is low in winter, the water-side economizer is activated to circulate the condensate water. Lowering the water temperature through cooling towers can reduce the load on the main unit.

Daily Monitoring And Data Management

Record parameters such as the supply and return water temperatures of chilled water, the flow rate of cooling water, and the current of the compressor every day. If the temperature fluctuation of the chilled water exceeds ±0.5℃, it is necessary to check for faults in the water pump or valve. If there is a constant difference in cooling water pressure, it may indicate that the filter screen is clogged.

How to Maintain A Centrifugal Water-cooled Water Chiller

Calibration of Chilled Water Parameters

Check the reset Settings of the chilled water and confirm that the temperature regulation function is normal.

Electrical System Inspection

Check whether all electrical connections are tight, and pay special attention to whether the terminal blocks are oxidized or loose.

Seals and Lubrication Management

Check the sealing condition of the flange joints of the compressor, condenser, etc. Replace them immediately if aging or oil leakage is found.

Deep Cleaning of Heat Exchangers

Disassemble and clean the evaporator or condenser pipelines of the centrifugal chiller every year to remove scale or corrosion.

Specialized Inspection of Compressors

Analyze the quality of the compressor oil. If its color darkens or it contains metal particles, it should be replaced immediately.

Vibration And Alignment Calibration

Use a vibration meter to measure the vibration value of the motor or compressor. If it exceeds the standard, check for worn bearings or loose bases.

Refrigerant Circulation Management

Monitor the refrigerant dosage through the high and low pressure gauges. Replenish when the liquid level is lower than one-third of the sight glass.

Enhanced Water Treatment

Install an electronic water treatment instrument and test the hardness of the cooling water (≤8°dH) every month. In hard water areas, scale inhibitors should be added every quarter, and the water lines of the condenser should be acid-washed once every six months.