Energy saving analysis of air fan motor in power plant boiler controlled by variable frequency drive

A reporting of Energy Audit in 2018 by LEMTEK UI has reported that air fan system currently used in Power Plant of PLTU Tanjung Jati B Jepara is inefficient, energy efficiency in FDF is only 32% and PAF efficiency is 49.01%. Inefficiency of the air fan system is an impacted there are waste of electric energy amount of 13,352,929 KWh (13,35 GWh) a year with a financial loss of IDR 13,352,929,140. To overcome this condition, variable frequency drive (VFD) is installed which adjusted air flow as needed so that energy waste can be reduced. MATLAB simulation is proposed to analyze the VFD method. The result shows that by using VFD, 8,233,573.444 KWh (8.45 GWh) can be saved a year. Total cost benefits are IDR 8,233,573,444 as 32.1% of saving cost. Efficiency of FDF is 72.57 % and PAF is 66.84%.

A Functional Safety Assessment Methodology for Explosion Protection with Application to a Variable Frequency Drive System

Modern explosion protection equipment, protected by traditional explosion protection technology (as defined by the international electrotechnical commission (IEC) publication IEC60079-ff series standards) and electrical/electronic/programmable electronic (E/E/PE) safety-related systems, is becoming ever more complex in coal mine development and petrochemical industry; thus, the possibility of failures in their operation is also growing. It is well-known that E/E/PE safety-related systems can be used to actively control dangerous sources, with real and expected levels of reliability, if they have been qualified according to the IEC61508-ff series standards. To uniformly evaluate the safety integrity level (SIL) of the explosion protection function of traditional explosion protection technology and E/E/PE safety-related system technology, this study analyzed the ability of these types of protection to remove the ignition risk residual, evaluating the failure rates of safety devices. The key objective of this paper is the presentation of a new equipment protection level (EPL) assessment method for explosion protection equipment based on a functional safety assessment. The method is applied to a variable frequency drive (VFD) system, and the results show that the EPL of the explosion protection equipment evaluated by this method is consistent with the EPL corresponding to the traditional explosion protection type of the IEC60079-ff series standard. Meanwhile, the flexible configuration of explosion protection safety devices and E/E/PE safety-related systems enables explosion protection equipment of different EPL levels to be designed.

AS-Solar, a Tool for Predictive Maintenance of Solar Groundwater Pumping Systems

Energy for water abstraction limits the viability of some irrigable areas. Increasing efficiency and introducing renewable energy can reduce energy cost. Solar pumping is a widely recognized renewable energy solution. These pumping systems suffer special wear out due to sudden changes and for having working conditions far from the nominal points. Thus, monitoring systems are becoming more frequent for maintenance issues. A new decision support system, named AS-Solar, was developed to perform predictive maintenance. This model permits detecting if the source of the anomaly in the pump performance is the pump, the electrical components (motor, variable frequency drive (VFD) or cables) or the pumping pipe. It demands real-time data from the monitoring system and an accurate simulation model, together with an optimization process that helps in the decision making in predictive maintenance. To validate the developed model, it was applied to a complex case study of a solar pumping system of 40 kWp that abstracts groundwater from nearly 200 m deep. This pumping system has a VFD, two lines of cables up to the pump and aggressive water with slimes, which causes different problems in the pumping system. In this case study, the AS-Solar model shows an acceptable accuracy, with a relative error (RE) of the 2.9% in simulated power and 7.9% in simulated discharge.

Design and analysis of smoke flow visualization apparatus for wind tunnel

In the present study, the design and analysis of smoke generator are done for the low-speed wind tunnel. The wind tunnel fan is fitted with the Variable Frequency Drive to produce the wind speed in the range of 3 to 32 m/s with fan speed of 150 to 1500 rpm. The design of smoke generator was done according to Preston Sweeting mist generator principle corresponding to the free stream velocity of 3 m/s. A controlled smoke generator consisting of kerosene reservoir, controlled heater, blower, liquid column height adjustment mechanism, valves etc. was designed and fabricated. The smoke generator produced the smoke at the rate of 154 cm3/s which was close to the design flow rate of 149 cm3/s. To supply the required quantity of smoke in the wind tunnel, the smoke rake of NACA 0010 profile was developed and installed in the rapid contraction section of the wind tunnel to achieve the streamlined flow. The parametric studies were done on the smoke generator at different power inputs and its effects were studied on smoke temperature, smoke discharge and boiling time of the kerosene. The flow visualization was carried out on NACA 0015 airfoil model and the images were captured to examine the flow physics around them under different operating conditions.

Motor Intelligence Versus Vibration Analysis for Early-Stage Diagnosis of Electric Submersible Pumps

The main objective of this paper is to investigate the condition monitoring based on electric signature analysis for electric submersible pumps (ESPs) as introduced in our previous paper, SPE-201169-MS. While an ESP core physical concept is similar to other rotary electric machinery, they have unique features which make their selection, installation and operation different than typical rotating equipment applications. For the purpose of this study, a scale-down ESP system and flow loop was utilized to replicate an actual ESP application. Condition monitoring of the ESP was completed with mechanically and electrically induced vibrations and compare the results vis-à-vis those obtained by a common vibration analysis method. Furthermore, by running the ESP at various operation points, we show how the mechanical and electrical efficiency of the pump, induction motor and variable frequency drive are intertwined. This observation may suggest an interesting insight for further discussion on ESP optimization.

Inclusion of frequency dependences into prediction model of conducted electromagnetic emissions for a VFD motor system

This paper presents a quantitative prediction model of conducted electromagnetic emissions (EME) for a variable frequency drive (VFD) motor system based on the macro-modeling approach. This model relies on the effective representations of the frequency dependent characteristics of the parasitic behaviors between converter arms and heatsink, of shielded power cable, and of motor windings. The frequency dependent performances between converter arms and heatsink, and of the motor windings are obtained by processing measurement data. Then the vector fitting method (VFM) with passivity enforcement and circuit synthesis method are adopted to obtain the corresponding equivalent circuits. The equivalent circuit implementation of shielded power cable is achieved by applying a node-to-node admittance functions (NAFs) model, which considers the propagation phenomenon and frequency dependent losses accurately. The conducted EME model is compatible with commonly used transient circuit solvers since it only includes constant circuit elements. The conducted emissions of the VFD system are then evaluated by analyzing the common mode (CM) and differential mode (DM) voltages and currents.

Applying Criteria Equations in Studying the Energy Efficiency of Pump Systems

This paper presents a method for evaluating the energy efficiency of pump systems used to transport fluids .It is mainly scientifically applied and engineering-applied in nature and aims to propose a new approach (method) to researchers in their study of the energy efficiency of such systems. By applying the well-known scientific method of Dimensional Analysis (Buckingham π-theorem), dimensionless complexes (π-criterions and their relevant equations, which are original (innovative) and are offered for the first time in the scientific literature), used in accomplishing an energy assessment and analysis of such systems, are obtained. The criterion ∏1 = ev/ρgD represents specific energy consumption in kWh/m3 for a given pipe system with an exemplary diameter D. The criterion ∏2 = Q/[n(Hp − Hst)D2] represents a generalized parameter which is characterized by the selected method of flow rate (Q) regulation for a pump system with given static head Hst—by changing the speed of rotation (VFD, Variable Frequency Drive), by throttling, leading to an increase of the system hydraulic losses hv = (HpHst) or by diverting a part of the flow, known as “by-pass”, where the pump operates with the required system head Hp, but ensures higher flow rates, i.e., Qp > Qs. The flow rate criterion ∏3 = Q/(νD) characterizes the flow rate for a pipe system with an exemplary diameter D, used to transport a liquid with known viscosity ν. An example for applying these dimensionless complexes in accomplishing a quantitative evaluation of the energy efficiency of a given pump system is presented. A method for determining the main parameters forming these criterions, used to describe the different methods of flow rate regulation, has been developed. To demonstrate the application of this method, newly proposed by the authors, including obtaining the relevant criteria equations of the type ∏1 = f(∏2, ∏3), a certain pump system was used. This original approach for studying pump systems used to transport fluids can be used both to accomplish an energy analysis of such systems as well as to solve for optimization or other engineering problems.