More electronics in the pump
Intelligent pumps communicate with the control room

Preventive maintenance ensures plant availability. Consequently there are benefits to be gained from also integrating the pumps into the control engineering system and managing and monitoring them using optimized adjustment algorithms.
Markus Reichling
There is probably no place where the working conditions for pumps are more demanding than in production plants for the chemicals industry: the properties of the media vary, and pumps are constantly having to handle changing feed volumes. To this, one could also add the often aggressive, abrasive or even environmentally hazardous media needing to be transported, calling for the use of high-quality materials and elaborate safety engineering.

Then there is the fact that, alongside safety, plant availability is often right at the top of the list of priorities for industry, and – last but not least – the lifecycle costs need to be included in the set of specifications. To satisfy these wide-ranging demands, it is a sensible approach to monitor and regulate feed media and pumps accordingly. Whereas in the past this has required a whole series of external devices (such as frequency converters, temperature/pressure/flow sensors, data storage devices or controllers), depending on the application, these have now been integrated into the pump itself for some considerable time. Thus, for instance, the electronically-regulated variable-speed drive with integrated micro-frequency converter comes as standard on Grundfos products. The integrated electronics allow for optimal adjustment of the pump to the operating conditions, improve availability and reduce electricity consumption by using optimized control algorithms.

Pumps as a configured solution

If the plant requirements are such that the pump is known to need to cope with different feed volumes, then the recommended choice is a pump with an integrated frequency converter to adjust its speed. In particular, this significantly reduces operating costs (energy costs) compared to using unregulated pumps, especially since CEMEP Class Eff1 optimized high-efficiency motors are used as the basis for the pump motors. The lower rev speed in partial load operation means that E-pumps also work very quietly. Today these are already available up to a size of 22 kW motor power. The sensor can be mounted directly onto the terminal box of the pump and the pump can be parameterized and adjusted.

For the operator, overall ease of use is improved through the simplified setting and changing of plant parameters, and by the better possibilities for control and monitoring:

Motor and frequency converter are optimally matched to one another.

Compared with a standard motor with an external frequency converter, the additional expense for wiring and installation is saved.

Compared with a standard motor with an external frequency converter, the pump can be installed in a smaller space.

Lower logistics costs (instead of a motor plus a frequency converter, only a single assembly needs to be ordered and perhaps kept in store).

Motor protection and controllers come as standard and are optimized for the pump.

Data bus connections to the control room are an option.

The aim of R&D at Grundfos is to integrate more electronics and thus more intelligence into the pump. In doing so, the use of electronic components should naturally not be at the expense of any additional risk. The primary focus is on developing reliable and robust electronic components. This is one of the reasons why Grundfos considers the development and manufacture of electronic components as a core competence and therefore controls this directly. The testing procedures in its own “electronics factory” in its parent plant apply Six-Sigma standards and guarantee the maximum possible quality. For a few years now, microprocessors integrated in the pump have already been gathering and analyzing the data relevant for safe and economical operation and, if necessary, intervening to effect adjustments to the pump operation. This allows for optimal control and adjustment of the pump.

The pump as part of process automation

Once you know that the electrical power consumption of a centrifugal pump changes to the power of three times the change in speed, the potential saving which this represents becomes apparent. This means that it is often worth installing an electronically speed-regulated pump in place of a constant speed pump and then running the new pump up to bring its speed to the calculated operating point. If this pump is then controlled via a data bus, having been optimized for its target value, the pump can react flexibly and safely to all changes in the process. Relevant data can be sent across the entire network via the data bus, and of course the central control station can control the pump in an optimal manner. Even preventive maintenance is made easier with this technology. Pumps with a data bus connection (e.g. Profibus-DP) are also available as dosing pumps, which are often integrated into the process in addition to the centrifugal pumps.

Conclusion: Integrating frequency converters, data bus technology, modern motor technology and optimizing control circuits into the pump offers many advantages to the user and operator. n