Use Of Power Meter Research Articles

Energy monitoring of manufacturing plants: a real case application

Industries are increasingly demanded to became more green and, at the same time, the process of becoming more connected and automated enabled the measurement of actual energy flows. Indeed, the use of power meters is increased and energy related KPIs are becoming more relevant. High industrial interest is pointed to monitor the energy consumption, to automatically assess energy efficiency, and to identify potentialities for improvement. Nevertheless, monitoring systems are often limited to a certain area or resource and the plant-level vision is not common. Also, the attention is often focused on a particular process, usually energy-intense. The work presents the application of an on-line energy monitoring system to the analysis of the overall plant consumption of a real factory in Italy. The factory produces a full range of valves and actuators for the most critical applications of Oil & Gas industry, and faces with high energy consumption due to the nature of the involved processes (i.e., welding, machining, painting, and high-pressure testing). Monitored data are used to understand plant hot-spots in terms of energy consumption and to create a map of the most (or least) efficient areas of the plant so that specific measures can be implemented to reduce carbon footprint. Indications for a data-driven monitoring system to enable the identification of unexpected and unwanted behaviors are defined.

The Replacement of the R404A Refrigeration System with The Environmentally Friendly R448A, to Improve Convenience Store Energy Efficiency in Thailand

This study presents the energy saving characteristics of the R448A, instead of the R404A refrigeration system, in 5 convenience stores, with a total of 150 m2, situated in Central Thailand. The R448A hydrofluorocarbons/hydrofluoroolefins (HFCs/HFOs) (GWP=1390) is a non-azeotropic mixture of R32 (26%), R125 (26%), R1234yf (20%), R134a (21%) and R1234ze (E) (7%), which can be retrofitted to replace the R404A refrigeration system. The R404A hydrofluorocarbons (HFCs) (GWP=3735) is a near azeotropic mixture of R125 (44%), R143A (52%), R134A (4%). Both refrigerants are composed of polyol ester oil (POE), are incombustible and non-toxic. The R448A has a higher cooling capacity (Qe) and lower global warming potentials (GWP) than the R404A due to its hydrofluorocarbons (HFCs) R32 component and hydrofluoroolefins (HFOs) R1234yf/R1234ze (E) component, as opposed to the R404A. This was determined by measuring power consumption (kWh) and the ambient temperature (°C) through the use of power meters and temperature data logger respectively. The result obtained was able to summarize the relationship of all the parameters concerned, and showed an energy-saving average of 7.9%, i.e. 28,273 kWh/year per 5 stores, and a decreased global warming potential (GWP) of 70%, through the use of a digital scroll compressor.

On Optimization of Pacing Strategy in Road Cycling

The wide-spread use of power-meters in today's competitive road cycling has been an incentive for optimizing the distribution of power output i.e. the pacing strategy. Therefore, the aim of this study was to examine the effects of course profile on the optimal pacing strategy in road cycling. For that reason, three course profiles, built up by cubical splines, were simulated with a numerical program for a fictional cyclist. The numerical program solves the equations of motion of the athlete and bicycle while an optimal design algorithm is connected to the simulation, aiming to minimize the time between start and finish. The optimization is constrained by a power-endurance concept named the critical power model for intermittent exercise. Three course profiles with the same total elevation but different number of hills were studied. The time gains of an optimized pacing strategy were 3.0%, 5.0%, and 2.3% and the speed variances at the optimized pacing strategy were 6.54%, 1.18%, and 0.84% for the single plateau, double hill, and quadruple hill courses respectively. Hence, the course profile has great effect on the optimal pacing strategy. In addition, the results show that the potential improvement of adopting an optimized pacing strategy is substantial at the highest level of competition.

Measurement of electric power using an optical fiber grating

AbstractThere is increasing motivation to develop sensors and actuators to manage domestic electric power consumption. This article demonstrates an optical fiber sensor using a superstructure fiber grating (SFG) to measure electric power consumption. The sensor head is based on SFG encapsulated in a polymer‐half‐field metal cylinder embedded a magnetic material at measure point. The operating mechanism is that the sensor can be attracted by the induced magnetic force created by the electric power in the solenoid along one radial direction only, and responds to an axial force on the magnetic rod attached to the round plate, creating an axial attraction on the SFG. Therefore, variations in attractive force cause center‐wavelength variations in SFB and long‐period grating acts as an edge filter converting strain‐induced wavelength variation into optical power measurement. Thus, the sensor can be used to measure electric power without the use of power meter. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2438–2441, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24660