Variable speed drive in fan system monitoring

Fan systems are responsible for approximately 10% of the electricity consumption in industrial and municipal sectors, and it has been found that there is energy-saving potential in these systems. To this end, variable speed drives (VSDs) are used to enhance the efficiency of fan systems. Usually, fan system operation is optimized based on measurements of the system, but there are seldom readily installed meters in the system that can be used for the purpose. Thus, sensorless methods are needed for the optimization of fan system operation. In this thesis, methods for the fan operating point estimation with a variable speed drive are studied and discussed. These methods can be used for the energy efficient control of the fan system without additional measurements. The operation of these methods is validated by laboratory measurements and data from an industrial fan system. In addition to their energy consumption, condition monitoring of fan systems is a key issue as fans are an integral part of various production processes. Fan system condition monitoring is usually carried out with vibration measurements, which again increase the system complexity. However, variable speed drives can already be used for pumping system condition monitoring. Therefore, it would add to the usability of a variablespeed- driven fan system if the variable speed drive could be used as a condition monitoring device. In this thesis, sensorless detection methods for three lifetime-reducing phenomena are suggested: these are detection of the fan contamination build-up, the correct rotational direction, and the fan surge. The methods use the variable speed drive monitoring and control options for the detection along with simple signal processing methods, such as power spectrum density estimates. The methods have been validated by laboratory measurements. The key finding of this doctoral thesis is that a variable speed drive can be used on its own as a monitoring and control device for the fan system energy efficiency, and it can also be used in the detection of certain lifetime-reducing phenomena.

Keskisarja vastaa yleistajuistamishaasteeseen

Vastine Raisa Maria Toivon kirjoitukseen "Peruskauraa viihdepakettina eli mitä esitetään yleistajuisesti” (HAik 2/2012).

[Kaksi vanhaa tukkijätkää]

Soitinnus: lauluäänet (TTBB), harmonikka, kitara, kontrabasso.

[Kipparit maailman merillä] : sikermä

Soitinnus: lauluäänet (TTBB), piano, kitara, kontrabasso.

Sähköt sain runoon

Musiikkiarvostelu

Psykiatrian historiasta laajasti

Kirjallisuusarvostelu

What is left of leadership when the leader is gone?

Tässä kandidaatintyössä tutkitaan voidaanko organisaatioissa määrittää johtajuutta, joka ei ole henkilöitynyt. Jos voidaan, mikä on ei henkilöön sitoutuneen henkilöitymättömän johtajuuden määritelmä ja mitkä ovat tällaisen johtajuuden elementit.

Ristiretkeläisten, pakanoiden ja saraseenien kohtaamisia

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Suurvallan historia

Kirjallisuusarvostelu

Ristiretkeläisten motivointi

Kirjallisuusarvostelu

Comparison of Model-Based Flow Rate Estimation Methods in Frequency-Converter-Driven Pumps and Fans

Fluid handling systems such as pump and fan systems are found to have a significant potential for energy efficiency improvements. To deliver the energy saving potential, there is a need for easily implementable methods to monitor the system output. This is because information is needed to identify inefficient operation of the fluid handling system and to control the output of the pumping system according to process needs. Model-based pump or fan monitoring methods implemented in variable speed drives have proven to be able to give information on the system output without additional metering; however, the current model-based methods may not be usable or sufficiently accurate in the whole operation range of the fluid handling device. To apply model-based system monitoring in a wider selection of systems and to improve the accuracy of the monitoring, this paper proposes a new method for pump and fan output monitoring with variable-speed drives. The method uses a combination of already known operating point estimation methods. Laboratory measurements are used to verify the benefits and applicability of the improved estimation method, and the new method is compared with five previously introduced model-based estimation methods. According to the laboratory measurements, the new estimation method is the most accurate and reliable of the model-based estimation methods.