chiller

Compression chiller

Vapor Compression Chiller
Compression chiller is a device for providing cold water with very low temperature, for air conditioning and industrial use. The compression chiller is based on the compression refrigeration cycle.
 
If used directly in large air conditioners, the cold produced directly will be very expensive and uneconomical, so instead of directly cooling the room air, cool the water in a tank and turn it into a converter to ventilate the room. They transfer heat such as fan coils or air conditioners, and this is the basis of the chiller structure.
 
• The main components of compression chillers
1- Compressor: The compressor can be of the reciprocating, spiral, centrifugal and in some cases snail type, depending on the capacity and design of the chiller.
2. Condenser: Depending on the model, design and capacity of the chiller, the condenser can be of blue or air type. The water condenser in the chiller is usually of the shell and pipe or plate type, and to heat the water with refrigerant and provide cold water, a cooling tower is needed, which is added to its facilities. Chiller air condensers are designed in two types: in the first type, the condenser is separate from the chiller and is installed in a space that is in contact with the open air, and in the second type, the condenser is installed on the chiller body, in which case The chiller must be installed outdoors.
 
3. Expansion valve: Depending on its design, the chiller expansion valve can be thermostatic, compression or electronic.
4- Evaporator: Chiller evaporator can be of shell and tube type, shell and coil or plate and its body is insulated to prevent heat loss.
• Subcompact chiller components
Compression chiller has different components. These components include tank receiver, side glass, dryer filter, protection switches, thermistors, accumulators and other electrical and control components.
• Chiller accessories
In cooling with a chiller, add-ons are also required to complete the system operation, including the following devices:
1- Pump: for water circulation in two routes of chiller evaporator to fan coil or air conditioner and also condenser to cooling tower (in water condensers)
2- Cooling tower: It is used in chillers with water condenser to cool condenser water.
3- Fan coil or air conditioner: In this system, one of these two devices is needed to provide cool air from cold water.
4- Plumbing, fittings and valves.
The refrigerant used in this device is usually Freon R134A and R-22, R407C.
 
Absorption Chiller
Absorption chillers are a good alternative to compression chillers, so one of the increasing uses of absorption systems is air conditioning. Absorption chillers reduce the cost of electricity consumption significantly by using low pressure steam, hot water or hot water. This type of chiller, like the cold water compression chiller required to provide air conditioning, such as fan coils and air conditioners.
Absorption chiller includes the following types:
1. Single Effect Chiller
The single-effect absorption chiller is the oldest and first generation of absorption chillers in the world, which has the lowest efficiency compared to other types of absorption chillers.
 
• The main components of single-effect absorption chiller
1. Evaporator: It is placed in the lower shell of the chiller.
2. Absorber or absorbent: Absorber is located in the lower shell of the chiller.
3. Generator: Located in the upper chamber of the chiller.
4. Condenser: The condenser is also located in the upper shell of the chiller.
5- Heat exchanger: This heat exchanger, as mentioned, is of shell and tube type.
6- Refrigerant pumps, solution and vacuum: The solution pumps are one on the aborbator and spray the solution on the abzurber and the other on the generator directs the dilute solution to the generator.
The vacuum pump also provides the necessary vacuum for the system.
These types of chillers require the vapor of an atmosphere to function in standard mode and consume about 8 kg per hour of steam per ton of refrigeration.
Economically, the initial purchase price of this chiller is more reasonable than other types, but its efficiency is much lower.
It is worth mentioning that the production of this type of chiller has almost stopped in the world, and if there is production, it is for the consumption of countries such as Pakistan and Iran.
2- Double Effect Chiller
Absorption chillers are two advanced and optimized types of single-effect absorption chillers. Two-stage absorption chillers in the same capacity as single-effect chillers have half the steam consumption. Of course, the consumption pressure of this chiller is 8 atmospheres.
This chiller model has a higher performance factor than the single-effect model due to its better design and optimal use of the thermal energy of the steam entering the device. The apparent difference between this chiller model and single chiller chiller is in the number of their generators.
The two-stage chiller has two primary and secondary generators that operate the High Stage Generator at a higher temperature.
The Low Stage Generator in the two-stage chiller absorbs some of the energy received from the refrigerant distillation by the dilute bromide solution of bromide and this preheats the dilute bromide solution of bromide.
• The main components of a two-stage absorption chiller
The components of this chiller are exactly the same as the single-impact chiller, except that there are two generators with primary and secondary names and in a heat exchanger with high temperature and low temperature names in this system.
 
In general, the bottom shell of this chiller is quite similar to the single-effect chiller, but the shell above the two chillers is different. In addition, refrigerant pumps and two-stage absorption chillers are one to two sizes larger than single-effect chillers.
This type of chiller requires steam at a pressure of 8 atmospheres to produce a ton of refrigerant at 4.5 kg / h.