COOLMATION Launches Predictive Adaptive Function Plus
Rhoss spa, represented exclusively in the UK by
the Coolmation Group, has launched its new innovative predictive
control system, Adaptive Function Plus (AFP) and is now integrating
it as the standard control system in its range of multi scroll
compressor chillers and heat pumps. By using a patented predictive
control the AFP system matches multi scroll compressor operation to
actual working conditions, thus reducing chiller/heat pump energy
consumption by as much as 36% in winter mode and 18% in summer mode.
Traditionally, control logics on water chillers and heat pumps ignore cooling load dynamics, instead they regulate according to return water temperature in order to maintain steady chiller/heat pump operation. However, the Adaptive Function Plus is different, in that it objectively optimises the chiller/ heat pump’s operation through information gathered from the load profile, then regulates the delivery water temperature up or down according to the load demands. A special adaptive algorithm and mathematical formulae is used to vary these values by managing the operation of each individual compressor.
It is well known that chillers and heat pumps only operate at full load for a small part of the year, and their part-load operation for the remainder of the year has a noticeable effect on seasonal energy performance and power consumption. These are precisely the conditions where the Adaptive Function Plus can make efficiency savings through its predictive logic. In simple terms, the AFP ensures that in chiller mode, the highest possible water leaving temperature is delivered while still maintaining user conditions, and in heat pump mode, the lowest possible temperature. This can result in 36% less energy consumed in heat pump mode, 18% in chiller mode and proportionate reductions in carbon footprint.
The ESEER (European Seasonal Energy Efficiency Ratio) is the normal measure by which the seasonal efficiency of a chiller or heat pump is gauged, or used to compare one against another. With the assistance of the IT Department of the University of Padova, which helped with development of the AFP, Rhoss has developed a formula which uses the improved results of Adaptive Function Plus control to calculate a new measure, ESEER+. All Rhoss catalogues featuring their chillers and heat pumps with AFP now show both measures, the standard ESEER, and the ESEER+ resulting from AFP Control which is equal to or better than Class A performance as defined by Eurovent.
A secondary but equally significant feature of the AFP control is the ‘Virtual Tank’ function which means the AFP can allow chillers and heat pumps to operate with considerably less water volume per kW of cooling or heating capacity. As a result, in some circumstances the AFP completely eliminates the need for a buffer tank without causing short cycling, impaired operation and premature failure normally associated with an insufficient system water volume.
With the AFP control a chiller or heat pump can operate with as little as 2 litres/kW of water. The AFP compensates by ‘muffling’ the control signal when the source temperature is reached, preventing the compressor from switching on and off abruptly and reducing the average fluctuation of the set-point value. As a result, the compressor is switched on less often saving energy, while the lower water content means that if one is required, a smaller buffer tank can be installed, saving space, installation time, glycol and water treatment costs