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Schlee (China) Refrigerating Equipment Manufacturing Co.,Ltd

Add:Jupu Road, Pukou Development Zone, Nanjing City, Jiangsu Province, China

Contact us:Annie





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Water Cooled Chiller Running Characteristics
- Oct 16, 2017 -

In the refrigeration industry is divided into air-cooled chiller and water cooled chiller two kinds, according to the compressor is divided into screw water chillers and vortex type water chiller, on the temperature control can be divided into industrial cold water machine in low temperature and room temperature cold water machine, cold temperature control in the range of 0-35 degrees. The cryogenic unit temperature control is generally about 0 to -100 degrees.

Cold water chiller is also called: freezer, refrigeration unit, ice water unit, cooling equipment and so on, because of the use of a wide range of industries, so the requirements of the cold water unit are different. Its working principle is a multi-function machine, which removes the liquid vapor through the compression or heat absorption refrigeration cycle.


In order to ensure the normal operation of the air conditioning engine after the operation of the air conditioner, it is necessary to guarantee that:

Heat dissipation of condenser is good, otherwise the cold - condensing temperature and corresponding condensation pressure will be too high, so that the cold water unit high voltage protection device action and stop, even cause failure.

(2) should be circulating evaporator in cold water, otherwise you will because of the cold water temperature is low, causing the cold water temperature protection device for parking, or due to the evaporation temperature and the corresponding evaporating pressure is too low, is a low voltage protection device action of the chiller and parking, even result in cold water and ice in the evaporator and damage equipment. Chiller, therefore, the boot sequence is: (must strictly abide by the cooling tower fan cooling water pump - > open - > cold water pump to open - > open chiller water chillers must strictly abide by) chiller stop order is: (- > - > cooling tower fan pause cooling water pump stop - > cold water pump stop


When the machine is shut down, the chiller should be closed half an hour before the work, and the cold water pump will be closed after work, which will save energy and prevent the failure of the shutdown and protection of the unit.

Before running the refrigeration cycle, it should be confirmed that the valve of the heat cycle pipe has been closed.

The type and operation characteristics of the chiller

1. The selection of the chiller shall be considered according to the cold load and use. For the cooling system with long working conditions of low load, it is appropriate to select a multi-head piston compressor or screw compressor unit for easy adjustment and energy saving.

2. The main control parameters of the screw chiller are the performance coefficient of refrigeration, rated refrigerating capacity, input power and type of refrigerant.

3. When selecting the chiller, the conditions of the nominal working conditions should be paid attention to. The actual cooling amount of the chiller is related to the following factors:

A) water temperature and flow rate of cold water; 

B) water inlet temperature, flow rate and fouling coefficient of cooling water.

4. When choosing cold water units, the units with high performance coefficient are given priority. According to the statistics, the normal water chiller operating time is about 1/4 of the total operating time under 100% load. The operating time ratio of 100%, 75%, 50% and 25% of total operating time was roughly 2.3%, 41.5%, 46.1%, 10.1%. Therefore, it should give priority to the model of the efficiency curve when choosing the chiller. At the same time, the adjustment range of the chiller load should be considered in the design selection. The multi-engine screw cold water chiller has excellent load performance and can be selected according to the actual situation.

5. When choosing the chiller, pay attention to the normal working range of the model unit, mainly the current limit of the main motor is the current value of the shaft power under the nominal working condition. 

6. Should be paid attention to in the design: under nominal working condition of flow rate, outlet temperature of cold water should not be more than 15 ℃, outdoor dry bulb temperature of air cooling unit should not be more than 43 ℃. If you have to exceed the above range, you should know whether the use range of the compressor is permissible and whether the power of the main motor is sufficient.

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