The basis of the work of chillers

When dealing with a chiller damage case, you need to prepare yourself for the complexities that come with it. These systems are usually complex and are customized based on the space or equipment they have, meaning that each has its own challenges for insurance regulators like you. If you are unfamiliar with this complex cooling device and are working on such a case, you will need to know the basics.

How do chillers work?

Chillers transfer heat from a space that requires temperature control and transfers it to another space. Something almost like what a split or package system does. But chillers use water (or water-soluble matter) instead of air. There are two types of chillers: water-cooled and air-cooled. The two-act similarly in most stages of the process, as far as condenser work is concerned, and both are discussed below.

How cold water chillers work

In general, the cooling process begins when water returns to the evaporator after returning from where the heat generated by the water has been transferred to the refrigerant.

The cooled water is then sent from the primary source (indicated in blue) to the water tank. From there, it is distributed by the pump to different parts under control. Since according to the second law of thermodynamics, heat always moves from hot to cold, cooled water absorbs ambient heat in the air conditioner. A fan then draws cool air into the environment through ducts. As a result, warmer water returns to the chiller to cool again.

Meanwhile, the heat absorbed by the refrigerant (the path is shown in green) needs to be changed in the evaporator to allow the refrigerant to absorb more heat in return. Therefore, a refrigerant with low pressure and high temperature moves from the evaporator to the condenser to increase its pressure and temperature.

After this step, the refrigerant enters the condenser. Cooling water chillers use water to surround the refrigerant tubes to get heat and cooling (path is shown in red). Water is then pumped to the cooling tower to release heat. After condensing in the condenser, the refrigerant enters the expansion valve to reduce the pressure (and temperature) before returning to the evaporator, where the steps are resumed.

How cool air chillers work

In these chillers, similar to cold water chillers, the process begins with the first return of hot water to the chiller. Inside the evaporator, heat is transferred to the refrigerant and water moves from the primary source to the cold environment. The refrigerant is passed through the compressor to increase the pressure and temperature and then reaches the condenser section. In this part, the fans circulate the outside air through the condenser, and this (again due to the second law of thermodynamics, which says that the movement is from heat to cold) removes heat from the refrigerant before it is released into the environment. The refrigerant (as before) then enters the expansion valve and returns to the evaporator.

Where are chillers used?

Chillers have many uses and are sometimes referred to as split systems or packages because water manages and conducts heat better than air. This is why cold water chillers are known for their stability, effective performance, and longer useful life than their other counterparts, cold air chillers. Coldwater chillers are common in medium and large structures and buildings (provided they have sufficient water supply) such as airports, hospitals, hotels, shopping malls, commercial buildings and more (Photo: A portable chiller) ).

In contrast, cool air chillers are common in small to medium-sized structures and buildings, where space and water resources are limited. These chillers cost less to install and maintain than their counterparts, cold water chillers but typically have a shorter service life. These chillers are commonly used for restaurants, corporate and sporting events, and temporary structures.

Chillers are also used for industrial or medical purposes. Assembly equipment, construction sites, lasers, MRI machines and other high-powered equipment and facilities may also be needed to keep the desired temperature of the chillers.

Common problems that affect the operation of chillers
Corrosion and rust

Chillers use metal pipes (usually copper or carbon steel) to transfer water between the chiller and the temperature control space. The presence of oxygen in the water can cause corrosion and rust, but if the water and pipes are properly cared for, it can significantly reduce this risk. At the same time, bacteria, minerals and sediments can enter the system even if the water treatment is not done well. If the accumulation of sediments and bacteria changes the oxygen level, it can lead to the onset of corrosion of metals. In addition, corrosion is likely to occur wherever two different metals are used due to their electrochemical properties. In the end, it does not matter how the corrosion occurred, but it can cause leakage and damage the chiller, reduce its effective performance, and even damage the space around where the chiller is located.

Poor maintenance

These sophisticated machines require a lot of maintenance to be able to maintain their good performance. If not taken properly, the chiller can cause corrosion, clogging, loss of efficiency, or other problems. For example, if proper water management measures are not taken or cooling towers are not cleaned, sediments or suspended particles can enter the system, clogging the pipes and impairing heat transfer. The condenser of a cool air chiller can also be clogged with debris and garbage, or covered with dust, which reduces the useful performance of the chiller.

Electrical problems

The electrical systems inside the chiller are carefully designed and complex like the rest of the machine. They can be easily out of balance by sudden high voltage currents or depletion. If there are ground connection problems or power supply faults, the chiller can detect them and turn them off. At the same time, working above the capacity of the chiller can raise its temperature more than usual, which will usually lead to a breakdown. Wires and cables can also become loose and damaged after maintenance or due to negligence, which also affects the positive performance of the chiller.

source:

https://www.hvacinvestigators.com/webinars/the-basics-of-chillers-how-they-work-where-theyre-used-and-common-problems/