Drive control of rotorsystems

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:

  1. an as large as possible speed range to exploit the entire heat recovery capacity of rotor systems
  2. 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.

Drive control of rotorsystems - rotor speedDrive control of rotorsystems - rotorspeed 2

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.

Drive control of rotorsystems - Linearised ratio

Example:

Control signal 5V = 50% of the reheat valueControl signal 1V = 10% of the reheat value

Drive control of rotorsystems - Control signal

Product descriptions / Tender offer text

The rotortronic VVX variable speed drive unit consists of a control unit and a gearless electronic step motor with reluctance motor. The motor cable is factory mounted for direct connection to the control unit. The variable speed drive unit is intended for the stepless speed regulation of the rotorsystems and an optimal heat recovery and high exploitation of the rotorsystem in the transition period.

Precise and low-noise drive without gears and with constant torque across the entire speed range.

rotortronic VVX 15 for rotors up to a diameter of 1.5 m

rotortronic VVX 25 for rotors up to a diameter of 2.5 m

rotortronic VVX 35 for rotors up to a diameter of 3.5 m

The connection of the control unit is done with monophase voltage, 230 V, 50 (60) HZ. In case of under- or overvoltage the motor is stopped by the control unit and starts up again once the voltage returns.

The following control signals can be processed:

0 - 10V, 2-10V, 0-20V, 4-20 mA, 0-20 mA, Potentiometer 10 kOhm.

By adding auxiliary cards, it is possible to process further control signals.

Advantages of the rotortronic VVX 15 - 35:

  • Digital display of the operational status
  • Digital display of the rotor speed
  • Constant torque across the entire speed range
  • Automatic purging mode during the transfer period retains the self-cleaning effect. The rotor is turned by 30° every 15 minutes and remains clean because of the continuous purging operation.
  • Soft start - about 90 seconds start-up time till maximum speed
    Rotation monitoring
  • System of protection IP 54
  • Variable speed drive motor factory-equipped with 2.5 m special cable for direct connection to speed regulation
  • There is a continuous comparison of the set value and actual value made by an electronic tachometer built into the variable drive motor.
  • The integrated electronic motor protection makes the installation of an external motor protection unnecessary. In case of an overload the power supply to the motor is interrupted. For a restart the power supply to the controller needs to be interrupted for about 5 seconds.
  • Low-noise and low-wear, maintenance-free gearless motor
  • Low operating costs due to high effectivity
  • CE mark of conformity

The detailed operating instructions on the rotortronic VVX variable speed drive units can be found in the chapter on assembly, operation and maintenance or in the Internet as a pdf file in the download area.

 

The rotortronic VVX 6 is the control unit for the variable speed drive system VVX 6 with gear drive for stepless control of rotary heat exchangers with constant torque across the entire speed range.

Rotortronic VVX 6 is employed for rotors up with a diameter of 3.5 m to 6.0 m.

The control has a soft-start function with a ramp time of about 90 seconds.

To ensure the self-cleaning effect an additional interval mode is run during the transition period for the purging operation. The rotor is turned by 30° every 5 minutes. This slight rotor rotation causes that no unwanted heat transfer takes place. The rotor remains clean due to the continuous rinsing operation.

There is a continuous comparison of the set value and actual value made by an electronic tachometer built into the rotortronic VVX 6 drive motor.

The integrated electronic motor protection makes the installation of an external motor protection unnecessary. In case of an overload the power supply to the motor is interrupted. For a restart the power supply to the controller needs to be interrupted for about 5 seconds.

The connection of the control is done with monophase voltage, 220 V, 50/60 Hz. In case of under- or overvoltage the motor is stopped by the controller and starts up again once the voltage returns.

Advantages of the rotortronic VVX 6:

  • Constant torque across the entire speed range.
  • Automatic purging operation during the transition period; the rotor is turned by 30° every 5 minutes.
  • Soft start about 90 seconds start-up time till maximum speed is reached.
  • Display of the operational status

Further advantages when installing the rotation transmitter:

  • Digital display of the rotor speed
  • Rotation monitoring

The detailed operating instructions on the rotortronic VVX 6 drive units can be found in the chapter on assembly, operation and maintenance or in the Internet as a pdf file in the download area.

 

The rotortronic RHX variable speed drive unit consists of a control unit and a gearless electronic step motor. The drive units RHX 19, 24 and 34 are superbly suited for the exact stepless speed regulation and a maximal heat recovery and high exploitation of the rotorsystem in the transfer range.

rotortronic RHX 19 for rotors up to a diameter of 1.9 m
rotortronic RHX 24 for rotors up to a diameter of 2.4 m
rotortronic RHX 34 for rotors up to a diameter of 3.4 m

The characteristics curve between the heat recovery efficiency and the set value has been linearised. Precise and low-noise drive without gears with constant torque across the entire speed range.

The connection of the speed control is done with monophase voltage. 1 x 230 V-AC ± 15 % , 50 Hz (60 Hz)

Power consumption at maximum load:

  • RHX 19 : 45 W
  • RHX 24 : 90 W
  • RHX 34 : 150 W

max. fuse: 16 A.
Control signal input: 0 - 10 V

The detailed operating instructions on the rotortronic RHX variable speed drive units can be found in the chapter on assembly, operation and maintenance as a pdf file in the download area.