Refrigeration systems are comprised of several different components including heating, cooling and ventilation and some are designed for specific purposes. Refrigeration is a term used to describe any mechanical process in which temperature and moisture levels are controlled. There are several types of refrigeration including free-standing, closed, semi-open, open and packaged. Refrigeration systems include hot water and condenser systems. Refrigeration is very common in industrial, pharmaceutical and food processing plants as well as some restaurants.
Industrial refrigeration systems often include air handling, condensing, drying, desiccating and chillers. Refrigeration is classified into two types; positive pressure and negative pressure refrigeration. Positive pressure refrigeration pumps circulate heated water through cooled lines while negative pressure pumps circulate cooled or warm air through cooled lines. In the UK, there are two main types of refrigeration including air-source and water-injected chillers. Air-source refrigeration requires an injection of a refrigerant into the lines to chill the air and remove heat. Water-injected chillers are similar but use water instead of air to chill the water.
Refrigeration cycles include the cooling of a product through one of two processes. The first is primary cooling and this occurs when heat is introduced into a system through a cold stream of refrigerant gas whereas the second is condensing cooling. In the industrial applications, refrigeration cycles are generally used to cool the systems after they have been loaded or when cold liquid products are ready to be transported. Some of the refrigeration cycles are illustrated below.
The mechanical compression refrigeration system was invented by J. E. Woolley and his team more than 50 years ago. This revolutionary air conditioning technology uses the principle of hydraulic reciprocity and accounts for its unique design. In the industrial applications, it can cool approximately four different items at the same time. The compressor, condenser, expansion valve and dryer work together to compress the refrigerant gas. Once the refrigeration systems have been cooled, they are returned to their storage racks.
The cooling water systems are more complex as they use pumps and solids concentration to regulate the temperatures of the incoming air. They can cool the systems to nearly zero and are capable of sustaining high pressure levels for lengthy periods. These types of systems are sometimes referred to as superheaters. In some industrial applications, they are called thermal oxidizers.
An air-conditioning or refrigeration system is usually designed with one or more fixed zones. Each zone contains a fixed volume of cool air and one or more zones designed to remove heat from the incoming air. Air is passed through a series of cooling chambers, called evaporator coils, to remove heat from the air. An evaporator coil cools the refrigeration coils and then returns the cooled air to the designated area.
Cooling towers are used to maintain the constant temperature inside the various zones. A cooling tower is usually designed to use pressurized air to carry out the heating and cooling processes. There are two types of cooling towers: positive displacement and dynamic. Positive displacement towers can only reduce the temperature if a current is run through them; dynamic cooling towers must run with a current to enhance the process and make them work. All three types of cooling towers can be used to cool air in the designated area.
Refrigeration systems require regular servicing and adjustment to make sure that they work at their optimal efficiency. If the service schedule is not followed, the machines may start to malfunction. Regular maintenance checks of the condition of your cooling towers and other components should be scheduled either by you or the servicing company that you contract with. It is important to adjust the makeup water temperature of these units to get the best performance and avoid the risk of explosions and power surges.
