AB Converters PF400 in the central air conditioning system design and application of

I. Introduction Most of the buildings in a year, onlyhighest level roughly constant, but most applications
several tens day oersted time, central air conditioningare maintained water valve opening some, any
in the maximum load. Central air conditioning coolingchange with pressure. If so, will lead to pressure loss
loads, always in dynamic change, such as morning andand low efficiency. At this point the use of a speed
evening, alternating on a quarterly basis, annual cyclecontrol to maintain optimum pressure, prevents
of environmental and human factors have immediatepressure loss and a more substantial increase in
impact on the central air conditioning cooling loads.energy efficiency and to achieve good results.
General, the cooling load in the range of 5 to 60%2, cooling water control By the cooling pump and
fluctuations, most of the buildings at least 70% ofcooling water piping and cooling tower component.
the time each year is in this situation. Most central airChiller for heat exchange, is the cooling water
conditioning, because the majority of system designtemperature at the same time, will release a lot of
with maximum cooling load for the maximum powerheat. The heat absorbed by cooling water is cooling
drive. In this way, they often cause the actual needswater temperature. Cooling pumps will be promoted
of the cooling load and the maximum power outputto the temperature cooling water into the cooling
of the contradiction between the actual cause greattower, so that the cooling tower heat exchange with
waste of energy to cause a huge user electricitythe atmosphere, and then lower and lower the
charges, increased operating costs, reduce businesstemperature of cooling water, get back to chillers.
competitiveness.This constant cycle of heat released chiller away.
This article describes AB Inverter PF400 water cycleCooling water pump control mode as follows:
in the central air-conditioning systems, fans andtemperature difference control.
cooling tower fan variable frequency in the designAs the water temperature is cooling tower with
and application.ambient temperature change, and its unilateral
2, PF400 water circulation in the central airfreezing temperature can not accurately reflect the
conditioning system designamount of heat units. Therefore, cooling water pump
Central air conditioning system water system isto water and backwater of the difference in
divided into chilled water (or water) circulation, coolingtemperature as a control based on water and return
water circulation system, intelligent frequencywater to achieve constant temperature difference
conversion control cabinet main target for the chilledbetween the control is more reasonable.
water (hot water) circuit and the cooling waterTemperature difference, which meant that the heat
circuit.generated by a large refrigeration unit, should
1, the control of frozen water cycleincrease the speed of the cooling pump, cooling
From the frozen pump and chilled water pipingwater circulation rate increases; the contrary, you
component, outflow from the chiller chilled watershould reduce speed.
chilled by the chilled water pump pressure into the3, inverter control principle Can see from the above
pipeline, in a heat exchange within the room, takeanalysis, water recycling system for central air
away the heat inside the room, so roomconditioning inverter control is generally poor or
temperature decline.constant temperature with constant pressure
Chilled water pump control mode are: top (or thedifferential closed-loop control, PF400 Inverter Has a
most negative side) pressure controlbuilt-in PID control loop, used to make the feedback
At the top of the central air conditioning system, airprocess the pressure difference or temperature
conditioning because each layer corresponds todifference is consistent with the set value.
changes in heat load of cold water inlet valves openIn PF400 the PID control, the ratio of output control
and close, thus regulating temperature. As the chilledoperation is the ratio between volume and bias.
water flow constantly changing, the highest levels ofI am a professional writer from China Quality Dress,
hydraulic pressure caused by larger changes in orderwhich contains a great deal of information about
to solve the problem, the need to control a coolingscuba air compressors , booster air compressor,
pump valve, hydraulic pressure to maintain thewelcome to visit!