subject: Centrifugal Chillers On The Feasibility Of Frequency Transformation - Air Conditioning, Chiller - [print this page] Unique control logic, synchronization, and degree of regulation guide vane switch Motor Speed, variable frequency drive through the transformation of plant operation with remarkable energy savings. Apply to hotels, hospital building and other 24-hour run, and day and night cooling load were significantly different place. In this paper, centrifugal water chiller Frequency Converter, from the advantages of transforming the contents of the three aspects of economic analysis, explained the feasibility of frequency transformation.
1, VSD advantages 1. Saving significant Use Inverter After centrifugal chillers achieve energy efficiency from two: one part load operating conditions of the energy, the second is a low-energy cooling water temperature.
running under part load energy efficiency:
We all know, water chiller running more than 99% of the time at partial loads. Typically, in part load, constant speed centrifuge opening by adjusting the guide vanes to adjust the output unit cooling capacity, peak efficiency is usually 70% to about 80% load, load reduction, increased energy consumption of unit cooling capacity more significant. The VSD continuously monitoring the following parameters: temperature, chilled water, chilled water temperature set value, the refrigerant pressure guide vane opening and motor speed. And adaptive capacity control logic for an effective regulatory approach. It will optimize motor speed and PRV (guide vane) of the opening so that the smallest unit running speed and efficient, minimize energy consumption.
To 500 cold-ton York centrifugal group, for example, in the cooling water temperature is 25, constant speed machine and inverter operation parameters in the following table:
Can be seen from the above chart, in part load conditions, frequency centrifuge group and compared to the same type of constant speed units, the units Refrigeration Amount of energy consumption is much lower. This is part of the load for long-term units, using conversion unit will undoubtedly save users a lot of electricity.
low cooling water temperature conditions to run energy-saving:
Unit at night, even in the winter season, running the transition, the cooling water temperature is often low. For the constant speed unit, the need for constant working conditions, which need constant evaporating pressure and condensing pressure. But the cooling water temperature decreases, the condensing pressure must make a corresponding reduction at this time, in order to meet the centrifugal Compressor Working conditions, only a small inlet guide vane through customs, reduce gas transmission capacity to adjust the centrifugal compressor operating point to accommodate the lower condensing pressure. However, the above adjustment has reduced the efficiency of the unit, no reason to consume more energy. The use of frequency converter, you can adjust the compressor speed to meet the condensing temperature, low cooling water temperature to maximize energy saving effect, to save energy.
Centrifuge same group of 500 tons of cold, for example, at 70% load, different condensation temperatures, constant speed machine and inverter operation parameters in the following table:
Unit in the low cooling water temperature, use the converter has a very significant energy savings, and the cooling temperature is lower, energy-saving effect of the more significant changes when the load is low, this effect is also more evident. For the transition into the winter season or for the use of the unit, install the inverter is very obvious advantages.
