//10 Ultimate Guides to Chillers – part 2

10 Ultimate Guides to Chillers – part 2

In general, water chillers system help transfer heat from the internal environment to the external environment. The heat transfer unit depends on the physical state of the refrigerant as it circulates through the refrigeration system. This article will inform you about the remaining 5 out of 10 tips for ultimate guides to water chillers.

Guide 6 – How to do when exhaust temperature alarm?

1. Analysis:

1) Suction pressure is too low, suction and exhaust pressure is too large (cylinder compression ratio), the expansion valve open small, low-pressure regulation.
2) Excessive suction temperature, i. e. excessive heat of suction, excessive length of suction pipe or poor insulation effect.
3) Insufficient cooling water or high water temperature.
4) Over non-condensable gas (Air) in the system.
5) The condensing pressure is too high together with the corresponding condensing temperature, Causing the exhaust temperature to increase.

2. How to solve it?

1) Check whether the suction pipeline is too long, whether the suction line insulated, excluding the suction pipeline caused by excessive heat.

2) Adjust the opening of the expansion valve to reduce the suction superheat and exhaust temperature of the compressor.

3) Check the condenser (cooling water, Cooling Fan).Excluding the condensation pressure on the high condensation temperature caused by high exhaust temperature factors.

Guide 7- How to do when evaporator frosting serious?

Evaporator frosted badly

1. Analysis:

Evaporator frosting reason for the overall evaporator heat transfer is not good. Not all the coolant was taken away

1) Insufficient air flow of evaporation fan and poor heat transfer.
2) The evaporator is too dirty, affecting the evaporator of heat transfer (water-cooled evaporator scale, air-cooled evaporator fins too dirty).
3) Too much refrigerant is entering the evaporator and heat transfer is inadequate; the expansion valve is open too wide; the refrigerant is overcharged
4) The temperature is too low and the humidity is too high.

2. How to handle it?

1) Clean the evaporator of the refrigeration system (water cooled, air cooled)
2) Check the evaporating Fan (water pump) , eliminate the causes of insufficient air volume caused by the malfunction of the evaporating fan;
3) Increase the airflow of the evaporation Fan (the circulating water of the frozen water)
4) Adjust the opening of the expansion valve to make the refrigerant entering the evaporator normal.
5) Drain The excess coolant.
6) Forced defrosting.

Guide 8- How to do if refrigeration system oil back bad?

1: Analysis:

1)  The dirty plug of oil return filter, a dirty plug of oil return pipeline cause the oil cannot come back.
2) The oil separator use time is too long, the efficiency drops.
3) When the exhaust temperature is too high, the efficiency of oil separation decreases.
4) Suction lines do not return oil, resulting in oil stored in the evaporator or another pipeline.
5) The opening of the expansion valve is too small, the frequency of the inverter compressor is too low, and the velocity of the refrigerant flow is too low to bring the oil back to the compressor.

2. How to fix it?

1) Clean the oil return filter and the oil pipeline.
2) Change the oil separator.
3) Suction pipe increase oil return bend.
4) Adjust the expansion valve opening, reduce the air temperature, increase refrigerant flow.
5) Add oil return operation mode at the low point of the pipeline, and turn on the oil return mode at intervals.

Guide 9 – How to do when compressor suction temperature too high?

1. Analysis:

Inspiratory temperature is too high, the main reason is too large with inspiratory tube refrigerant has been endothermic, resulting in inspiratory temperature is high. the reasons are as follows:

1) the refrigerant is insufficient, the refrigerant in the evaporator is already overheated;
2) the expansion valve is blocked or the pipeline is blocked, which causes the evaporator refrigerant to be insufficient;
3) the opening of the expansion valve is too small;
4) the length of the suction pipe is too long or the insulation of suction pipe is not good.

The reasons are mainly concentrated in two points: 1. less refrigerant; 2. Suction Pipe Problems

2. How to fix it

The main reason: 1 Suction Pipe 2 Refrigerant

1) Make sure the suction pipe insulation.
2) Increase the opening of the expansion valve to reduce the suction superheat.
3) Increase the refrigerant charge.
4) Eliminate the reasons for expansion valve jam and Pipeline Jam

Guide 10- How to judge whether the refrigerant charge is sufficient?

1) Liquid optic microscopy :

Observe the Liquid Lens, if there is no bubble in the liquid lens, then the refrigerant charge is enough.

2) Current method:
Measure the compressor current, and the nameplate marked on the running current. if the current is almost the size of the refrigerant charge enough.

3) Pressure gauge method:

Observe the operating pressure of high and low pressure, according to the environmental conditions (or water temperature) to estimate the condensing temperature of the compressor, and the actual temperature indicated by the pressure gauge, small, then the refrigerant charge may be insufficient.

4) Return Air superheat method:

General refrigerating systems have 3-8 of the return gas superheat, if the degree of overheat, then the refrigerant may be insufficient, if the degree of overheat is small, then the refrigerant excess.


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By |2019-01-18T12:07:51+00:00January 18th, 2019|Updates|