How to choose air conditioning main engine? What does common air conditioning main engine have?

一、WATER-COOLED CHILLERS:
 
The water cooled chiller is part of the chiller in the air conditioning, and its refrigerant is water, called the Chiller, and the condenser is cooled by heat exchange of normal temperature water. So called water-cooled units, and water-cooled units known as the opposite of air-cooled units, air-cooled units by the condenser and outdoor air forced ventilation heat exchange to achieve refrigeration since.
1、Screw chillers: Screw chillers are large and medium-sized chillers that provide chilled water. Commonly used in National Defense Research, energy development, transportation, hotels, restaurants, light industry, textile and other departments of air conditioning, as well as water conservancy and power engineering frozen. The screw type chiller is a complete refrigeration system which is composed of screw refrigeration compression group, condenser, evaporator, automatic control element and instrument. It has the advantages of compact structure, small volume, light weight, small area, convenient operation and maintenance, smooth operation and so on, so it has been widely used.

2、Centrifugal chillers: chillers are made up of Centrifugal chillers, complete with evaporators, condensers and throttling controls, and electrical meters. The capacity of a single chiller ranges from 700 to 420OKW. Applicable to sub-large and extra-large projects.

二、AIR-COOLED CHILLERS:
water-cooled chillers and air-cooled chillers, the main difference between them lies in the condenser. The condenser of a water-cooled chiller takes away heat mainly by circulating cooling water. Unlike water-cooled chillers, air-cooled chillers use fans for cooling. Finned condenser is usually used. The finned condenser is actually a piece of aluminum. The area where the heat transfer is about to take place is externally mounted with the finned condenser for efficient heat dissipation. The hot air is then discharged through a powerful fan.
The modular machine was developed on the basis of the VRV system, which was invented and patented in 1985 by the Czech Wind Group of Australia. It will change the traditional Freon pipeline into the water system, the combination of indoor and outdoor units into refrigeration units, indoor units into fan coil. The refrigeration process is realized by the heat transfer of the refrigerant water. The module machine is named because it can automatically adjust the number of starting machine according to the requirement of cooling load and realize flexible combination.

AIR-COOLED WATER SCREW MACHINE:
The difference between air-cooled screw and water-cooled screw is that a condenser adopts a fin-type condenser, another is a tube-shell type condenser, which is suitable for a large cold capacity factory, market.
三、VRV system

VRV system is the abbreviation of variable Refrigerant Volume system, I. E. Variable Refrigerant flow system. Its form is a group of outdoor machine, by the function machine and constant speed machine, frequency conversion machine composition. Through the parallel outdoor machine system, the refrigerating pipe is centralized into a pipe system, and the suitable capacity of the indoor machine is selected from 122.5 kw to 1.5 kw according to the matching of the capacity of the indoor machine, that is up to a group of outdoor units can be connected to 30 indoor units.

Indoor machine has ceiling embedded type, hanging wall type and so on. Different types of indoor single machine can be connected to a refrigeration loop, and can be controlled separately. The minimum capacity of indoor single machine is 0.6 kw and the maximum is 3.75 kw. The capacity of indoor machine can be adjusted from 50% to 130% of outdoor machine capacity.
四、How to choose a refrigeration unit
Calculate air conditioning cooling load according to the air conditioning area and room function of the building;
Statistical Building Air conditioning total load;
Most buildings need to consider the simultaneous use of rooms, the general simultaneous use of buildings for 70-80% , special circumstances need to be determined according to the building function and use;
The cooling load of the refrigerator is the product of the total air-conditioning load of the building and the simultaneous utilization ratio. According to the calculated cooling load of the refrigerator, both the refrigeration host can be selected;
The number of refrigeration units can be determined according to the building owner and the equipment room provided
The type of host machine can be determined according to the actual situation of the owner or according to the project situation, and the most suitable type of host machine can be chosen.
An office Gross leasable area for 2000 square meters, air-conditioning area for 1500 square meters, the whole building to use VRV system, should choose how much cooling capacity of the external unit?

Calculations based on Empirical Cooling Capacity: 1500 m2200w/m2 = 300kw/2500w = 120hp.