Chiller system basics

What is a chiller system? You can view our selection of air-cooled chillers here. By the end you should be able to identify the main components and the main circuits of a chiller.

Refers to a chiller or chiller system that is used in the medical industry. Chillers and Cooling Towers - Chilled Water System Basics.

It is the condenser barrel where the refrigerant is condensed and sent back to the evaporator barrel to remove the heat. The process is in reverse in the condenser barrel. The water absorbs heat from the refrigerant and allows it to condense.

In an absorption chiller , the generator uses a high-temperature energy source, usually steam or hot water, which flows through the tubes and boils off the refrigerant into vapor. The vapor moves to the condenser and the concentrated solution returns to the absorber. Large buildings with cooling loads in excess of 4tons of refrigeration or 4kW typically use water cooled chillers with either centrifugal compressors or Turbocor compressors within the central plant cooling system.

They might also use a separate smaller air cooled chiller to handle the critical cooling loads such as computer and communication rooms.

There are many types of refrigerant and applications depending on the temperatures required but they all work on the basic principle of compression and phase-change of the refrigerant from a liquid to a gas and back to a liquid. Process chillers contain a chemical compoun called a refrigerant. The air conditioning machine that cools the water is called a chiller , and it will be located in a dedicated machinery area somewhere in the building, on the roof, or outside. The basic cooling cycle is the same for both absorption chillers, and vapor-compression. Both of these systems utilize a liquid refrigerant that changes phase to a gas within an evaporator which absorbs the heat from the water to be cooled.

This cool fluid removes heat from the process and the warm fluid returns to the chiller. How does a Chiller Work? There are several types, and each type offers specific pros and cons based on the application, facility budget and available energy sources. The chilled water circuit of a typical water chiller system will consist of a pump, cooling coils, expansion tank, and piping valves and controls, in a closed loop.

The temperature of the chilled water supplied to the loop will depend on the set point of the chiller. A centrifugal chiller utilizes the vapor compression cycle to chill water and reject this heat collected from the chilled water plus the heat from the compressor to a water loop cooled by a cooling tower. Figure shows the basic refrigeration circuit. In this article we will learn how to locate these on the chiller and briefly what their purpose is.

Basic refrigeration cycle training is essential for safe and efficient power plant operations. Air-cooled chillers can be used as a single piece unit or a split in various configurations. This flexibility has contributed to their overall popularity among designers of chilled-water systems.

Set on cooling, a basic refrigeration principle is used: A condenser removes heat and is on the “hot” side of the air conditioner. In most air conditioning systems geared for cooling, the principal refrigerant is chilled water. An absorption chiller is different to other chillers because it doesn’t have a compressor. Instead it uses heat to generate cooling. System designers may get the most use from this manual by familiarizing themselves with chilled-water- system basics and understanding the benefits of various options.

Thereafter, when a specific job will benefit from these advantages, consult appropriate sections of the manual in detail. The closed-loop dry cooling system fluid cooler will be located outside and use the ambient air to reject the heat.