RHOSS Compact-Y SM TCAEY 122 P0 Instrucciones De Uso página 24

2. High precision: "Precision" option
In this operating mode, the unit works at a fixed set-point and, thanks
to the delivery water temperature control and the evolved regulation
logic, at a capacity of between 50% and 100% it is possible to
guarantee an average fluctuation from the water supply temperature
of approximately ± 1.5°C from the set-point value compared to an
average fluctuation over time of approximately ± 3°C, which is
normally obtained with standard return control.
The "Precision" option thus guarantees precision and reliability for all
those applications that require a regulator that guarantees a more
accurate constant water supply temperature, and where there are
particular damp control requirements. However, in process
applications it is always advisable to use a water buffer tank or a
greater system water content to guarantee higher system thermal
inertia.
s
s
fluctuation
FC
capacity
Unit with water buffer tank, 4 litres/kW in the system and
return control.
Unit with water buffer tank, 2 litres/kW in the system and
delivery control with "Precision" AdaptiveFunction Plus
function
The chart illustrates the fluctuations of the water temperature from the
set value for the various capacities, demonstrating how a unit with
delivery control and the AdaptiveFunction Plus "Precision" function
guarantees greater water supply temperature precision
Virtual Tank: guaranteed reliability, even with water in the
pipes only
A low water content in the system can cause the chiller units/heat
pumps to be unreliable and can generate system instability and lack of
performance. Thanks to the Virtual Tank function, this is no longer a
problem. The unit can operate in systems with just 2 litres/kW in the
pipes given that the control is able to compensate for the lack of inertia
specific to a water buffer tank, "muffling" the control signal, preventing
the compressor from switching on and off in an untimely fashion and
reducing the average fluctuation of the set-point value.
T
14
12
10
8
6
4
2
0
2000 3000 4000
T
Water temperature (°C)
t
Time (s)
FC
T1
Set-point temperature
Delivery temperature with Virtual Tank
Delivery temperature without Virtual Tank
The chart shows the various chiller outlet temperatures considering
capacity of 80%. We can observe how the temperatures of the unit with
AdaptiveFunction Plus logic and the Virtual Tank function is far less
varied and more stable over time, with average temperatures closer to
the working set-point compared to a unit without the Virtual Tank
function. Moreover, we can see how the unit with AdaptiveFunction
Plus logic and the Virtual Tank function switches the compressor on
less often over the same period of time, with obvious advantages in
terms of energy consumption and system reliability.
ACM Autotuning compressor management
AdaptiveFunction Plus enables the Compact-Y units to adapt to the
system they are serving, so as to always identify the best compressor
operating parameters in the different working conditions.
During the initial operating phases, the special "Autotuning" function
enables the Compact-Y unit with AdaptiveFunction Plus to estimate
the thermal inertia characteristics that regulate the system dynamics.
The function, which is automatically activated when the unit is switched
on for the first time, executes a number of set operating cycles, during
which it processes the information relative to the water temperatures. It
is thus possible to estimate the physical characteristics of the system
and to identify the optimal value of the parameters to be used for the
control.
At the end of this initial auto-estimate phase, the "Autotuning" function
remains active, making it possible to adapt the control parameters
quickly to every change in the water circuit and thus in the system water
contents.
24
Compact-Y SM
5000 6000 7000 8000
T1
t
9000