Advantages and disadvantages of condensation pressure adjustment of FNH, FNH,FNV,FNVT capacitors in cold climate.
In winter, when the outdoor temperature is very low, FNH, FNH,FNV,FNVT capacitors often work at too low condensation pressure. This leads to the failure of expansion valve, insufficient refrigerant flow to DL, DD and DJ evaporators, and irregular operation of the whole refrigeration equipment. Condensation pressure adjustment solved this problem.
The main goal of the system is to keep the high pressure within the specified minimum range, regardless of the external ambient temperature. In this way, the expansion valve has the necessary pressure difference to correctly power the evaporator of the refrigerating chamber.
There are several technologies to choose from: fan partial switch adjustment, continuous variable speed EC fan, hot air recirculation electric shutter and hot gas bypass valve. Each has advantages and limitations, depending on the size and type of installation.
Fan local shutdown regulation is the most extensive economic solution. Its disadvantage is staggered operation: the pressure jumps up and down, and it does not keep a completely stable value. It works well in small and medium-sized facilities.
The EC fan with continuous adjustment function has the highest stability. They change the speed without jumping and keep the condensation pressure almost constant. The initial investment is high, but the start-stop cycle and mechanical wear are reduced.
The electric shutter circulates some hot air discharged from the condenser to its entrance. They are suitable for very cold climates, but mechanical maintenance of the shutter mechanism is required.
Hot gas bypass is the last choice. It involves transferring hot gas from the compressor to the liquid side to increase the pressure. It generates extra energy consumption, so it should only be used when other solutions are not feasible.
A common mistake is to set the target pressure value too high. This makes the capacitor work under high voltage even in summer, which unnecessarily increases the power consumption of the compressor and shortens the service life of the components.
All these regulating systems indirectly affect the thermal performance of DL, DD and DJ evaporators, ensuring a stable flow of refrigerant in all winter weather conditions.
FAQ
What is the purpose of condensation pressure adjustment? Keep the minimum high pressure to ensure the normal operation of the expansion valve in winter.
What are the disadvantages of fan switch adjustment? The pressure changes with the jump, and it will not be completely continuously adjusted.
Which solution can improve the stability of condensation pressure? EC fan with continuously changing speed.
When to use the hot gas bypass? As the last choice, it will bring extra energy consumption to the system.
What if the target pressure is too high? Increase energy consumption in summer and accelerate compressor wear.
Key words: condensation pressure regulation, winter refrigeration system, EC fan, electric louver condenser, hot gas bypass, FNH condenser, FNV condenser, FNVT condenser, DL series air cooler, DD series air cooler, DJ series air cooler.
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