A Chiller Compressor plays a crucial role in refrigeration and air conditioning systems by compressing the refrigerant gas. Its primary function is to increase the pressure of the refrigerant, which leads to an increase in its temperature.
Below is the function of Chiller Compressor:
- Compression of Refrigerant Gas – The compressor draws in low-pressure, low-temperature refrigerant gas from the evaporator coil. It then compresses this gas, raising both its pressure and temperature. The resulting high-pressure, high-temperature gas is sent to the condenser.
- Cycle Continuity – By compressing the refrigerant, the compressor ensures that the refrigerant continuously circulates through the chiller system, maintaining the refrigeration cycle. This cycle is essential for the chiller to absorb heat from the environment and reject it to the surroundings.
- Energy Transfer – The compressor converts electrical energy into mechanical energy, which is used to compress the refrigerant. This energy transfer is essential to the chiller’s operation, as it drives the entire refrigeration process.
- Control of Cooling Capacity – The compressor controls the system’s cooling capacity by regulating the flow of refrigerant through the cycle, often in conjunction with other system components like expansion valves or variable frequency drives (VFDs).
Types of Chiller Compressors
There are several types of compressors used in chiller systems, and each one is suitable for different applications and cooling capacities. The common types include:
1. Reciprocating Compressors
- Mechanism – These use pistons that move back and forth within cylinders. The refrigerant gas is drawn into the cylinder and compressed by the piston’s movement.
- Applications – Best for smaller, low-capacity systems.
- Advantages – Reliable, relatively simple design, good for applications that require variable cooling loads.
- Disadvantages – Can be less energy-efficient for larger systems, noisy operation.
2. Screw Compressors
- Mechanism – Uses two interlocking helical screws (rotors) to compress the refrigerant. The gas is trapped between the rotors and compressed as they rotate.
- Applications – Common in medium to large capacity systems, widely used in commercial chillers.
- Advantages – Efficient for medium-to-large cooling loads, quiet operation and handles varying load conditions well.
- Disadvantages – Higher initial cost compared to reciprocating compressors.
3. Centrifugal Compressors
- Mechanism – These compressors use a rotating impeller to increase the velocity of the refrigerant gas, which is then converted into pressure.
- Applications – Common in large, high-capacity chiller systems (e.g., industrial and large commercial buildings).
- Advantages – Very efficient for large cooling capacities, suitable for systems that require continuous load and high efficiency.
- Disadvantages – Expensive and complex, less effective at partial load operation.
4. Scroll Compressors
- Mechanism – These use two interleaved scrolls to compress the refrigerant. One scroll remains stationary while the other orbits around it, drawing in and compressing the refrigerant gas.
- Applications – Often used in small-to-medium-sized air conditioning and chiller systems.
- Advantages – Quiet, smooth operation, compact size and high efficiency for small-to-medium loads.
- Disadvantages – Limited to systems with moderate refrigerant capacities, higher cost compared to reciprocating compressors.
5. Rotary Compressors
- Mechanism – These use a rotating mechanism to compress refrigerant gas. A rotor inside the compressor pushes the refrigerant around the housing, compressing it.
- Applications – Used in smaller, commercial chiller systems.
- Advantages – Smaller, simpler design than screw compressors, good for smaller cooling applications.
- Disadvantages – Less efficient for large systems and can be less reliable at high capacities.
Summary
- Reciprocating compressors are best for smaller systems, while screw compressors and centrifugal compressors are better suited for larger capacity systems.
- Scroll compressors offer smooth and quiet operation for smaller loads.
- The choice of compressor depends on factors like system capacity, efficiency, cost, and specific cooling needs.
Each type of compressor has its own advantages and is chosen based on the requirements of the chiller system.
Several well-known brands manufacture high-quality chiller compressors, each offering a variety of models tailored to different refrigeration and cooling needs. Here are some of the top brands in the chiller compressor market:
- Carrier
- Danfoss
- Bitzer
- Emerson (Copeland)
- Mitsubishi Electric
- LG Electronics
- Fujitsu General
- Kobelco
These brands are some of the top names in the chiller compressor industry, each offering different types of compressors, including scroll, reciprocating, screw and centrifugal types, to meet the needs of various commercial, industrial, and large-scale applications. When choosing a compressor, it’s essential to consider factors like cooling capacity, efficiency, reliability and service support.