Thermo-6 – Saving Energy with Energy-Control
In view of rapidly rising energy costs, potential savings in energy consumption are becoming increasingly important in the plastics processing industry. HB-Therm AG has anticipated precisely this circumstance in the development and implementation of the new Thermo-6 unit generation and offers several features for more energy efficiency in the operation of the temperature control units. These include the standard speed-controlled pump in combination with the "Energy-Control" assistant for determining the optimum operating point using temperature control units equipped with a speed-controlled pump, energy and thus costs can be saved by reducing the pump speed.
By using a speed-controlled pump, the pump characteristic can be adapted to the application so that the desired flow rate is achieved with minimum energy input. And that is the crucial aspect: achieving the optimum temperature control with as little energy as possible. In most cases, however, it is not clear from the outset what the correct flow rate is for a process. It thus makes sense to control the temperature differential in a temperature control circuit. In this way, the component quality can be guaranteed and at the same time the flow rate and thus the pump power can be reduced to the necessary minimum.
An example of cost saving
The following example shows the possible savings by using a speed-controlled pump. Here, the flow rate was reduced by half, because instead of the original temperature difference between main and return line of 0.5 K, 1 K was sufficient. Thus, with a reduction of the speed from 3 000 to 1 500 min-1, a flow rate reduction by 12.5 L/min could also be achieved. With 6 000 operating hours per year, a total energy saving of 4 200 kWh and an assumed price of 0.25 euros per kWh, this results in 1 050 euros less energy costs per year with only one unit. The current prices for kWh are usually even higher, so that the amortisation of a temperature control unit with speed control is further reduced.
Always the optimum operating point with the assistant "Energy Control"
With "Energy-Control", an optimal operating point can always be achieved in just a few steps. The result is up to 85 percent less power consumption. The Energy Control Assistant correlates the variables pump speed, temperature differential and energy savings. Finding the optimum operating point is made easier by a simple visual display that shows the current pump speed, the difference between main and return line in Kelvin and the savings per year in euros. If the user adjusts one of the variables, the other two change in the same measure, and the probable effects of the change are immediately apparent. The setting can be accepted at the touch of a button. With the assistant "Energy-Control", every user can find the optimal operating point, even without special knowledge about regulation. Energy Control can be restricted to authorised users by means of an input lock with code.