Fan Motor Research Articles

Generator Mini dengan Prinsip Termoelektrik dari Uap Panas Kondensor pada Sistem Pendingin

In daily life, it is often found that office buildings and shopping centers use air conditioning system (AC Central) for room cooling. The refrigerant in the cooling system releases the heat into the air with the help of the motor fan. In order to release the heat faster, the condenser pipe winding is designed and equipped with fins. The heat released from the condenser will be discharged to the air. This will lead to global warming if large numbers of air conditioning system are used. In this case, thermoelectric technology is a main alternative solution that can be implemented. Thermoelectric converts heat energy directly into electrical energy. Therefore, in this paper, we design a simple power system by utilizing waste heat energy from a condensor based on thermoelectric method. Based on the result of the experiment, an average temperature of 34°C results in voltage of 3.14 Volts and power of 0.16 Watts.

A wind tunnel study of aeolian sediment transport response to unsteady winds

Although moderate attention has been paid to the response of the aeolian mass transport rate to wind gusts, it is still unclear how the particle size and volumetric concentration affect this relation. Very little is known about the response time of the particle speed, and specifically, how the sensor scale and elevation affect measurements of this variable. The present study addresses this knowledge gap through a series of wind tunnel experiments in which a gusty wind was generated by programming the fan motor to adjust to a randomly selected rpm every 10s. Beds consisting of either medium or coarse sand were investigated through synchronous, co-located measurements of the local wind speed and particle speed/count rate obtained via a customized laser Doppler anemometry (LDA) system. The vertically integrated sand transport rate (Q) and the wind speed in the freestream were quantified using a passive sand trap and pitot tube, respectively. The results of the experiments indicate that the response of the aeolian transport system to wind gusts is generally faster in terms of the particle speed than the mass transport rate, while the degree of correlation is found to vary with the sensor elevation, as well as with the particle size and volumetric concentration. In essence, the coupling within the transport system is demonstrated to be strongly scale dependent.

Investigations on a virtual airflow meter using projected motor and fan efficiencies

Airflow measurements are not as accurate as needed in air-handling units due to space and cost limitations of physical meters. Generally, the airflow in an air-handling unit is propelled by a fan driven by a motor and, hence, the airflow rate is related to fan-motor system performance, which can be affected by other measurable variables, such as fan head and motor power. Theoretically, a virtual airflow meter can be developed to virtually obtain the airflow rate from measured fan head and motor power along with projected motor and fan efficiency models. Because variable frequency drives have been widely installed in HVAC systems, a comprehensive motor efficiency model is needed to project motor efficiency under variable frequency and voltage. At the same time, an in situ fan efficiency curve needs to be projected through a calibration process corresponding to actual fan head measurement. This article explores a theoretical model of virtual airflow meters in order to identify the relationship of fan airflow rate with measurable fan head, motor power, and power frequency and voltage; then, demonstrates a procedure to implement a virtual airflow meter and validate the virtual fan airflow meter through an experiment. The results show that airflow measurements from the virtual airflow meter match very well with a conventional duct mounted airflow meter with an standard deviation of 0.0177 m3/s (37.5 cubic feet per minute [CFM]) for instant measurement and 0.0142 m3/s (30.1 CFM) for a 5-min moving average with the measured airflow range between 0.45 m3/s (950 CFM) and 0.70 m3/s (1,480 CFM).

Parameter Estimation of Permanent-Split Capacitor-Run Single-Phase Induction Motor Using Computed Complex Voltage Ratio

Equivalent circuit parameters and performance variables of permanent-split capacitor-run single-phase induction motor can be obtained from dc test, no-load test, locked-rotor test, and using turns ratio as derived from the winding ratio test (the last one is carried out if the design data are not available). In this paper, turns ratio has been replaced by a computed complex voltage ratio, based on an assumption that single-phase motor for parameter transformation can be represented as an ideal transformer. The equations for this complex quantity have been derived that provide an alternative to winding ratio test, which otherwise requires the tedium of a physical test on the motor. The performance variables like input current, power factor, and power consumed by the motor, obtained by the proposed technique, have been compared with those obtained using the conventional techniques as well as with the experimental observations obtained on three fan motors of different ratings. It is observed that the proposed method gives performance variable values closer to the experimental observations in comparison to those obtained using the conventional methods.

Investigation of Multiple Miniature Axial Fan Cooling Solutions and Thermal Modeling Approaches

This paper investigates the thermal and fluid dynamic characteristics due to multiple miniature axial fans with blade chord and span length scales less than 10 mm, impinging air onto finned surfaces. A coupled approach, utilizing both experimental and numerical techniques, has been devised to examine in detail the exit air flow interaction between cooling fans within an array. The findings demonstrate that fans positioned adjacently in an array can influence heat transfer performance both positively and negatively by up to 35% compared to an equivalent single fan—heat sink unit operating standalone. Numerical simulations have provided an insight into the flow fields generated by adjacent fans and also the air flow interaction with fixed fan motor support structures downstream. A novel experimental approach utilizing infrared thermography has been developed to locally assess the validity of the numerical models. In particular, an assessment on implementing compact lumped parameter fans and fans modeled with full geometric detail is shown for two configurations that are impinging air onto finned and flat surfaces. Overall, the study provides an insight into fan cooled heat sinks incorporating multiple miniature axial fans and general recommendations for improving current numerical modeling approaches.

Optimum number of engines for transport aircraft employing electrically powered distributed propulsion

Realizing a significant reduction of enroute emissions with respect to greenhouse gases is one major challenge in aircraft design today. Conventional kerosene propulsion systems are going to reach their efficiency limits in near future and it will be very ambitious to fulfill the requirements for future aircraft transportation using conventional engines. Consequently, new approaches for propulsion system design and integration are required to further improve aircraft efficiency through synergy effects. In this paper, a universally electric, short-haul, medium-capacity aircraft utilizing electric motors and battery for motive power is used as datum. The focus lies on the impact of a distributed propulsion system on the aircraft design and flight performance and will not discuss the advantages and disadvantages of the used reference aircraft configuration. Initial studies were performed identifying that the critical design cases for electric motor sizing are the one-engine-inoperative (OEI) flight segments, i.e., the climb gradients required at take-off and landing as well as field length requirements. By increasing the number of installed engines (i.e., motor–fan combinations) the OEI performance requirements may be satisfied with a reduced amount of installed motor and battery system power. An integrated aircraft performance analysis is conducted to estimate the possible net benefit in terms of increased aircraft range when increasing the number of installed engines. Aerodynamic efficiency degradation is considered as well as weight impacts due to electric motor scaling and necessary system architecture modifications. The analysis shows that a 6 % increase in aircraft design range can be achieved when going from 2 to 4 installed propulsive devices.

小形ファンモータの振動騒音特性の実験的解明に関する研究

In this paper, the phenomenon of vibration and noise in a small fan motor caused by electromagnetic forces were experimentally investigated. First, vibration characteristics of the fan motor in a non-operating state were determined by experimental modal analysis. Next, vibration and noise characteristics of the fan motor in an operating state were determined. The rotational speed was continuously decreased from 2200 r/min to 1200 r/min while the measurements were taken. A detailed frequency analysis was also performed to investigate the directional patterns of noise at the rotational speed which the significant resonance were confirmed. In addition, analysis on the vibration and noise of the fan motor after turning off its power were performed. As a result, it was found out that the significant vibration and noise were generated in the axial direction, and were resonance phenomena between harmonic frequency of electromagnetic force and natural frequency of the fan.

Motor soft starters in electric drives used in mining machinery

This paper analyzes the selection of the type of a starter for electric drives with high-voltage synchronous motors depending on the nature of the change in the load torque of the mechanism, the amount of driving synchronous motors to be started up (single motor or successive start of several motors), and the technological regime requirements, as well as the parameters of the synchronous motor. Single-line schemes of implementing the soft starters of driving high-voltage synchronous motors of large grinding machines and axial mine fans for main and auxiliary ventilation are given.

1101 パッケージエアコン室内機用ターボファンの高効率化

We confirmed the superiority of the flow of the new 3D-blades by Computational Fluid Dynamics(CFD) for the high efficiency of the turbofan for package air-conditioner indoor units. As a result, the new 3D-blade fan reduces the flow-separation at the leading-edge and blows out uniformly form the outlet of the fan. In addition decreasing of 15% of axis power by the CFD result, and reducing of fan motor input 11% by the actual machine evaluation.

냉각팬 모터 제조공정의 품질개선에 관한 사례연구

The purpose of this study is to present a case study of six sigma quality improvement practice in cooling fan motor(CFM) manufacturing processes. In this study, the CFM manufacturing process of automobile parts not relevant to the target process rate of the process point of view, in order to reduce the system to solve the problem of localized resolution procedures of six sigma DMAIC methodology was applied to study. In conclusion , this study 's field D in order to improve the initial rate of inadequate quality management best practices by applying the method of Six Sigma quality CFM failure through stabilization schemes were proposed cost reduction .To be CFM product to satisfy customers based on continuous monitoring of the effective field of claims quality management system is required. Keyword : Quality Improvement, Six Sigma Technique, Case Study, CFM, DMAIC, Quality Management

Design and characterization of miniature fluid dynamic bearing using novel multi-step elliptical grooves

This paper investigates the design and characterization of a miniature fluid dynamic bearing using novel multi-step elliptical grooves for small-form-factor data storage applications and miniature fan motors. In contrast to conventional herringbone-grooved cylindrical journal bearings (HGJBs), the proposed journal bearing contains a single set of multi-step elliptical grooves (EGJB). The performance of the proposed multi-step EGJB is characterized numerically using proprietary flow field analysis software. In addition, to reduce the number of optimal full-factorial experimental design tests (323), the Taguchi parameter design methodology is used to find out the optimal design parameters of the multi-step EGJB. Results show that compared to the conventional HGJB presented by the current group in a previous study, the proposed multi-step EGJB improves the load capacity. Consequently, the proposed motor represents another solution for both existing and emerging miniaturized spindle motor applications.

Design of an exhaust air energy recovery wind turbine generator for energy conservation in commercial buildings

The exhaust air energy recovery wind turbine generator is an on-site clean energy generator that utilizes the advantages of discharged air which is strong, consistent and predictable. Two vertical axis wind turbines (VAWTs) in cross-wind orientation which are integrated with an enclosure are installed above a cooling tower to harness the discharged wind for electricity generation. It is mounted at a specific distance and position above the cooling tower outlet. The enclosure (consisting of several guide-vanes and diffuser-plates) acts as a wind power-augmentation device to improve the performance of the VAWTs. The guide-vanes are placed in between the discharged air outlet and the wind turbine. They are designed to guide the on-coming wind stream to an optimum flow angle before it interacts with the rotor blades. The diffuser-plates are built extended from the outlet duct of the exhaust air system. They are tilted at an optimum angle to draw more wind and accelerate the discharged air flow. A particular concern related to public safety which may be due to blade failure is minimized since the VAWTs are contained inside the enclosure. The performance of the VAWTs and its effects on the cooling tower's air intake speed and current consumption of the power-driven fan were investigated. A laboratory test was conducted to evaluate the effectiveness of the energy recovery wind turbine (5-bladed H-rotor with 0.3 m diameter) generator on a cooling tower model. The results showed a reduction in the power consumption of the fan motor for cooling tower with energy recovery turbine compared to the normal cooling tower while the intake air speed increased. Meanwhile, the VAWT's performance was improved by a 7% increase in rotational speed and 41% reduction in response time (time needed for the turbine to reach maximum rotational speed) with the integration of the enclosure. This system can be used as a supplementary power for building lighting or fed into electricity grid for energy demand in urban building. The energy output is predictable and consistent, allowing simpler design of the downstream system. The fact that there is an abundance of cooling tower applications and unnatural exhaust air resources globally causes this to have great market potential.

Vibration Strength Estimation of a Structure-Borne Source: Case Study for a Reception Beam

This paper presents the estimation of vibration strength obtained from reception structure method. It describes a laboratory-based measurement procedure, which determines the strength of a vibration source in terms of its total squared free velocity. The source used in the experiment is a small electric fan motor. Here instead of using the usual flat rectangular plate, a thin stainless steel beam was used as the reception structure. The aim is to validate the data obtained from the reception method with that from the direct measurement. A good agreement is found between the two results, although small discrepancies occur due to the modal behavior of the beam.

Comparison of different fan control strategies on a variable air volume systems through simulations and experiments

Through a variable frequency drive (VFD), a variable air volume air handling system can significantly reduce supply fan power under partial load conditions. Typically, the VFD on a supply fan motor is modulated to maintain a supply air duct static pressure set point. The static pressure set point can be either constant or dynamically reset in response to different load conditions. In this paper, comprehensive mathematical models are established to describe the performance of a VFD-motor-fan system under three different static pressure control strategies: constant static pressure set point, static pressure reset by total airflow rate, and static pressure reset by highest zone demand. The total input power to the system, including the energy imparted into the air as well as the energy losses from the VFD, motor, and fan, are simulated and compared among the different static pressure reset strategies with different minimum airflow ratios. The simulation results show that more than 50% of electrical power savings can be realized by static pressure reset when the diversity of the zone thermal loads is moderate. In addition, although a lower minimum airflow ratio can result in more power savings, there were no significant power saving by reducing the minimum airflow ratio from 30% to 10% due to relatively high energy losses of the fan, motor and VFD at low load and speed conditions. Finally, experiments were carried out to demonstrate the performance comparison of three different control strategies.

Suppressing Bearing Voltage in an Inverter-Fed Ungrounded Brushless DC Motor

This paper describes the bearing voltage reduction achieved by the brushless dc motor for air conditioning driven by the voltage source inverter. First, the simplified equivalent circuit of the brushless dc motor is derived based on the common-mode equivalent circuit where stray capacitance is taken into account. Then, the electrostatic capacity distributions between a winding and a stator core, a winding and a magnet, a stator core and a magnet, and magnet capacitance are measured, and the bearing voltage is calculated with the simplified equivalent circuit. It is confirmed with the experiment that the bearing voltage can be suppressed when the inside and outside of the rotor core are insulated with resin (hereafter, the insulated rotor) and that the electrostatic capacity of the rotor is made smaller. Finally, a bridge-type equivalent circuit is derived in an air conditioning fan motor where the frame is not grounded, an insulated rotor is actually designed, and the bearing voltage is measured.

DESIGN AND SIMULATION OF SHUNT ACTIVE POWER FILTER FOR ASSIUT CEMENT COMPANY DC MOTOR DRIVE

This paper introduces a design and simulation of an adaptive shunt active power filter (APF) for harmonic mitigation and power factor (PF) correction of 630 kW DC motor (DCM) drive (called By Pass Motor Fan in production line # 2 in Assiut cement company). Due to the presence of power thyristor converters, a very bad PF and different harmonic components exist in the system, especially in the input current to the DCM drive. All measurements needed for complete analysis at the Medium Voltage (MV) supply source side and at Low Voltage (LV) motor drive side are performed using professional power quality (PQ) analysers and their associated software programs. The studied system is modelled and simulated using MATLAB Simulink software. The instantaneous active and reactive current components id and iq control method is used in this study to drive the shunt active filter. Therefore the harmonic contents at MV supply source and at point of common coupling (PCC) with the DCM drive are reduced to the standard values. Both digital simulation and practical measurements are presented and consistent. The results show that a good dynamic and steady-state performance of the system is achieved.

A Driver for the Single-Phase Brushless DC Fan Motor With Hybrid Winding Structure

This paper mainly proposes a novel driver for a single-phase brushless dc fan motor with a hybrid series/parallel winding structure. The winding symbols and directions of the hybrid motor stator structure are defined, and the winding steps for the proposed series/parallel winding are explained. An adequate inverter driving circuit, which is capable to simultaneously obtain the advantages of the hybrid structure, is also discussed. At last, the overall system of this hybrid brushless dc motor with the proposed driving circuit is then implemented to verify the performance of the proposed driver and structure.

Detection of Mass Increase in a Fan Impeller With a Frequency Converter

Fan systems are often responsible for the ventilation of contaminated air, such as exhaust gases. Contaminants can build up on the fan impeller eventually causing a mechanical imbalance, which may lead to the fan breakdown and shutdown of production processes. Usually, the contamination buildup can be detected by visual inspection or from increased vibrations caused by the imbalance on the fan impeller. If the contamination buildup could be detected before the imbalance occurs, the unscheduled maintenance or even the failure of the fan system could be avoided. In this paper, a novel method is presented that can be used to detect the contamination buildup on the fan impeller. The method uses the capability of the frequency converter controlling the fan motor to estimate the rotational speed of the motor and the capability to control the motor torque. The presented method is validated by laboratory measurements.

Innovative Method to Achieve Product Quality Convergence and Optimal Electrical Energy Consumption by Changing Motor Frequency in Batch Annealing

The batch annealing process is used for heat treatment of coils output of the cold rolled process. In this process, high speed fan motors are used to generate strong convection currents and thermal heat convergence in all coil layers. Several factors could affect product quality grade. In this work by changing the motor speed, optimal frequency is reported to have the highest quality convergence and lowest energy consumption. For testing, frequencies of 45, 55, 65 and 75 Hz were tested. The results showed that there is highest quality convergence and lowest electrical energy consumption in frequency of 55 Hz. The practical solution represented in this work can be used to achieve optimal frequency for each condition.

Exhaust air energy recovery system for electrical power generation in future green cities

This paper investigates a technology-driven solution to supply a portion of energy demand in future green cities. An idea on harnessing unnatural wind resources for electricity is presented. Two vertical axis wind turbines with an enclosure are mounted above a cooling tower to recover part of the energy from the exhaust air. Guide-vanes are designed to create a venturi effect and guide the wind before it interacts with the turbine blades. Diffuser-plates help to draw more wind and accelerate the exhaust airflow. Safety concerns that may result from blade failure are minimized by the design of the enclosure. From the laboratory test and field test results, there is no significant difference in the current consumption of the fan motor with the installation of the wind turbines. The integration of the enclosure has shown an improvement on the turbine’s rotational speed which is 30.4% higher. The electricity generated from this system can be fed into the electricity grid. For 3000 units of cooling tower (2 m outlet diameter powered by a 7.5 kW fan motor and operated for 16 hours/day), 13% of the energy to power the fan motor is expected to be recovered from this system which equals 17.5 GWh/year.