Frequently troubled by temperature faults in refrigeration equipment? 5 Ways to Easily Distinguish

With the improvement of people's living standards, the demand for refrigeration equipment continues to rise in various industries, especially in the pharmaceutical industry. However, other pharmaceutical companies are troubled by the fact that refrigeration equipment is prone to malfunctions after prolonged use, resulting in high power consumption and low exhaust temperatures. A refrigeration equipment manufacturer has summarized some daily problems encountered based on customer feedback on temperature issues, and has made the following summary.
The exhaust temperature of the refrigeration system is too low
The low exhaust pressure is mainly caused by the refrigerant flow rate in the refrigeration system pipeline being too small or even stopping. Although the phenomenon of low exhaust pressure is manifested at the high pressure end, many reasons arise at the low pressure end.
The common cause of low exhaust pressure is blockage of the expansion valve hole, which reduces or even stops the supply of liquid. At this time, both the suction and exhaust pressures decrease. In addition, ice or dirt blockage of the expansion valve and filter blockage will inevitably cause a decrease in both suction and exhaust pressures
The suction temperature of the refrigeration system is high
There are three main reasons for high suction temperature in refrigeration systems:
Firstly, poor insulation of the return gas pipeline or excessively long pipelines can cause high gas temperatures. It is reported that under normal circumstances, the compressor cylinder head should be half cool and half hot.
Secondly, insufficient refrigerant charging in the system, or excessively small opening of the expansion valve, can result in insufficient circulation of refrigerant in the system, insufficient refrigerant entering the evaporator, high superheat, and thus high suction temperature.
Thirdly, the expansion valve port filter is clogged. The supply of liquid in the evaporator is insufficient, the amount of refrigerant liquid is small, and a part of the evaporator is occupied by superheated steam, resulting in an increase in suction temperature.
Low evaporation temperature of refrigeration system
The evaporation temperature has a significant impact on refrigeration efficiency. According to the manufacturer's introduction, for every 1 degree decrease, an increase of 4% in power is required to produce the same cooling capacity. So, if conditions permit, increasing the evaporation temperature appropriately is beneficial for improving refrigeration efficiency.
In general, the evaporation temperature is 5-10 degrees lower than the outlet temperature, "the manufacturer said. Although blindly reducing the evaporation temperature can cool the temperature difference, the cooling capacity of the compressor is reduced. Therefore, the cooling speed may not be fast. Moreover, the lower the evaporation temperature, the lower the refrigeration coefficient, while the load increases, the operating time prolongs, and the power consumption also increases.
Low suction temperature of refrigeration system
There are two reasons for the low suction temperature of the refrigeration system:
Firstly, it is due to the expansion valve opening being too large. Due to loose binding of the temperature sensing element, small contact area with the return pipe, or failure to wrap the temperature sensing element with insulation material and incorrect wrapping position, the temperature measured by the temperature sensing element is inaccurate and close to the ambient temperature, which increases the opening degree of the expansion valve and leads to excessive liquid supply.
Secondly, the refrigerant charge is too high. Excessive refrigerant charge can occupy the internal volume of the condenser, leading to an increase in condensation pressure and an increase in liquid entering the evaporator. The liquid in the evaporator cannot be completely vaporized, resulting in liquid droplets in the gas sucked in by the compressor. In this way, the temperature of the return gas pipeline decreases, but the evaporation temperature remains unchanged due to the pressure not decreasing, and the degree of superheat decreases. Even if the expansion valve is turned down, it cannot significantly improve.
Methods for diagnosing faults in refrigeration equipment
The common methods for identifying faults in refrigeration equipment are observation, listening, touching, testing, and analysis. The so-called observation refers to carefully observing the working condition of each component of the refrigeration equipment, focusing on the refrigeration system, electrical system, and air system, to determine whether they are working properly.
Listen, it means turning on the power and carefully listening to whether the compressor is operating normally, whether there is any noise from the fan due to abnormal noise, and whether the noise is too loud. In general, refrigeration equipment operates with slight vibration and low noise under normal circumstances. Taking air conditioning as an example, if there is excessive vibration and noise, it is likely due to improper installation, abnormal compressor vibration, fan impact, etc.
Touching the relevant departments of the refrigeration equipment with your hands to feel its temperature, vibration, and other conditions can help determine the nature and location of the fault.
Measurement is to accurately determine the nature and location of faults, often using instruments and meters to check the performance parameters and status of measuring equipment.
Analysis shows that the various parts of refrigeration equipment are interrelated and influence each other. Users also need to comprehensively compare and analyze local factors in order to accurately determine the nature and location of the fault.