Winter Approaches: How to Solve the Low High - pressure Issue of Air - cooled Condensing Units?

2025-02-20

In winter (when the ambient temperature is relatively low), the condensing pressure of the condenser is often very low.

Winter Approaches: How to Solve the Low High - pressure Issue of Air - cooled Condensing Units?1740064345174

This reduces the pressure drop across the expansion valve, resulting in less refrigerant reaching the evaporator, thus causing malfunctions in the refrigeration system.

1. Fault of Excessively Low Condensing Pressure

In a refrigeration system, if the condenser is installed outdoors, the discharge pressure (condensing pressure) of the system is often relatively low in winter (or in a low - temperature environment). This is more common in northern areas. This situation is not only applicable to air - conditioners but also to other equipment like cold storages.

An excessively low condensing pressure makes it impossible for the expansion valve to obtain a sufficient pressure drop across its two ends. As a result, it's difficult to supply an appropriate amount of refrigerant to the evaporator. On one hand, the refrigeration capacity of the system fails to meet the requirements. On the other hand, the system frequently experiences malfunctions such as low - pressure alarms.

2. Several Ways to Increase Condensing Pressure in Low - temperature Conditions

2.1 Using a Discharge Pressure Controller

Intermittent fan operation is simple and practical, and the technology is well - established. The controller employed is a pressure controller, which can regulate the intermittent start - stop of the fan.

2.1.1 When the pressure is too low, shut off the fan.
2.1.2 When the pressure is too high, turn on the fan.
Generally, for small - capacity units, two or more fans are used. One fan operates continuously, while the rest are controlled by the pressure controller. The start or stop of these fans is determined by the level of the condensing pressure.

2.2 Controlling Fan Speed

[The original text seems to be about introducing speed - regulating equipment, perhaps something like "The figure above shows a speed governor and a three - phase frequency converter", but due to insufficient information, it's hard to provide an accurate translation.]

2.
3 Using an Air Volume Control Device

The main component is a louver - type air volume control device. Its principle involves using a piston - type damper driven by high - pressure refrigerant. This control device can achieve a stable discharge pressure, just like a fan - speed controller.

Winter Approaches: How to Solve the Low High - pressure Issue of Air - cooled Condensing Units?1740064345267