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Design Considerations for Switched Reluctance Machines
Published in Berker Bilgin, James Weisheng Jiang, Ali Emadi, Switched Reluctance Motor Drives, 2019
Rotational speed of the rotor can be expressed in revolutions per minute (rpm) nm, revolutions per second (rev/s, Hz) fm (or fmech), or radians per second (rad/s) ωm. Revolutions per minute (rpm) is frequently used to express the rotational speed of a motor. The relationship between angular speed (also called angular frequency), ωm, and nm is: () ωm=π30nm
Energy Audit
Published in Anil Kumar, Om Prakash, Prashant Singh Chauhan, Samsher, Energy Management, 2020
Anil Kumar, Om Prakash, Prashant Singh Chauhan, Samsher
Speed measurements are critical and a challenging task in audit exercise as it may change with frequency, belt slip, and loading. A tachometer is an instrument measuring the rotation speed of a shaft or disk, as in a motor or other machine in revolutions per minute (RPM). Contact type tachometer can be used wherever direct access is possible. More sophisticated and safer ones are non-contact instruments such as stroboscopes.
Applications of Sensors to Physical Measurements
Published in Robert B. Northrop, Introduction to Instrumentation and Measurements, 2018
RPM is the shaft’s revolutions per minute. One way of measuring the phase angle, θ, is to use a PDIC, such as the Motorola MC4044. The MC4044 has a working range of ±360° and generally can be used to resolve angles as small as ±0.1°. Obviously, to measure low values of torque, a PD is needed that can resolve hundredths of a degree or better and work over a wide range of frequencies.
Co-pyrolysis of Juliflora biomass with low-density polyethylene for bio-oil synthesis
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2021
Midhun Prasad k, Murugavelh Somasundaram
The experiments were conducted in an auger reactor made of stainless steel. The length of the reactor is 1.49 m and width is 0.29 m, internal diameter of the tubular reactor is 0.16 m shown in Figure 1. A screw feeder inside delivers the feedstock. The reactor consists of mainly five components (1) feed hopper, (2) inconel tube which served as a reactor, (3) electrical furnace, (4) condensing column, and (5) control unit. Feed hopper delivers the biomass into the reactor. The hopper is designed to hold 8 kg of JF biomass, the conical shape helps in uniform flow of biomass. Tubular reactor has a capacity of 14 kg. The rotation of the screw helps in the movement of feed from the hopper to the end of the reactor. The screw feeder is coupled with a shaft on the both sides, one end is connected with the motor for the rotation of the shaft and the other end is fixed with a bearing to avoid vibration in shaft. Furnace acts as the source of heat. The tubular reactor is covered by furnace by its all sides and the edges are coated with heat-resistance material to avoid heat loss in the furnace. The coil present inside the furnace heats the walls of the reactor. Heat is transferred from the wall of the tubular reactor to the biomass. The vapor liberated from the reactor is condensed using a condensing column of 5,000 ml capacity. The condensation of volatile gas components is achieved by circulating chilled water at 10°C. The reactor is supplemented with a control panel which consists of eight segment Proportional–Integral–Derivative (PID) controller made of siemens S7-1500, which helps for the fixing of temperature and heating rate for the reaction. A tachometer is provided for measuring theROTATION PER MINUTE (RPM) of the shaft. The temperature at various sections of the reactor is monitored using six k-type thermocouples of Emerson Rosemount 214°C temperature sensor.
Condition-based monitoring as a robust strategy towards sustainable and resilient multi-energy infrastructure systems
Published in Sustainable and Resilient Infrastructure, 2023
Nita Yodo, Tanzina Afrin, Om Prakash Yadav, Di Wu, Ying Huang
Components in energy infrastructure typically have different lifespans and criticality. Longer-lifespan components usually do not need to be monitored as frequently as shorter-lifespan components. Any critical components need to be observed as frequently as possible because the failure of critical components may cause deliberating impact on the overall energy infrastructure network. Based on the periodicity of the data collection for monitoring, CBM can be classified into three categories as follows. Periodical monitoring: Periodical monitoring is typically performed using a portable data logger with one or more sensors. The most used sensors are vibration and temperature sensors. Besides, a tachometer or stroboscope is used to measure a machine’s rotation per minute (rpm). The collected data are stored at the data logger and uploaded to the maintenance server for further analysis. Depending on the potential failure characteristics and the cost-effectiveness, the commonly practiced periodicity for this type of condition monitoring is biweekly or monthly.Semi-online monitoring: The CBM process can be shifted to semi-online monitoring when running the periodical monitoring becomes difficult. The semi-online monitoring uses wireless sensors mounted on the machine body and automatically transfers the data to the maintenance server through a wireless connection. This type of monitoring is suitable for machines that work continuously at a relatively constant load. The commonly practiced periodicity for this type of condition monitoring is one data per day to check if there is any parameter that crosses the threshold limit.Real-time, near real-time, or online monitoring: When monitoring for a particular type of machine that works at variable load, does not work continuously, and a variety of process parameters need to be monitored, then the real-time monitoring system can be considered. The machine condition is constantly monitored, and an alarm is triggered when the health parameter reaches the threshold. In this type of condition monitoring, data is collected one time per hour or more. The data logger used for this application can recognize different sensor readings for various parameters, such as rpm, pressure, current, airflow, and others.