Drive systems rotortronic VVX and rotortronic RHX
For an optimal exploitation of the heat recovery capacity of rotorsystems the speed regulation devices need to fulfil two criteria above all:
- an as large as possible speed range to exploit the entire heat recovery capacity of rotor systems
- linearised ratio between temperature efficiency and control signal
1. As large as possible speed range:
If the maximum temperature efficiency of the rotorsystem is needed in the winter, then the rotorsystem runs at the maximum speed of 10 rpm. An as large as possible speed range is important in particular during the transfer period, that is when only part of the heat recovery output of the rotorsystem is needed. Figure 1 shows that the temperature efficiency at on to two rpm is only 50 %. For conventional drive systems this range of 1 to 2 rpm is already the lower limit of the control range – there is a switch then to purging mode. There is no heat recovery during the purging mode.
To achieve an as large as possible exploitation during the transfer period (see Figure 2) the rotorsystem still needs to be run at much lower rotations per minute.
The rotortronic drive units can run the rotor system still with 0.05 rpm. This guarantees a nearly maximum exploitation of the heat reclaiming capacity in the transfer area.
2. Linearised ratio between temperature efficiency and control signal:
The rotortronic drive units feature an integrated linearisation function that make a linear relationship possible between the control signal and the characteristics of the heat exchanger's effectivity (Figure 1) instead of a speed proportional to the control signal.
Control signal 5V = 50% of the reheat valueControl signal 1V = 10% of the reheat value