scholarly journals POWER EFFICIENCY OPPORTUNITIES FOR INDUSTRIAL REFRIGERATION SYSTEM OF FOOD PROCESSING ENTERPRISE

2017 ◽  
Vol 52 (6) ◽  
Author(s):  
O. Ostapenko ◽  
O. Zimin ◽  
I. Podmazko ◽  
M. Khmelniuk
Keyword(s):  
Power Consumption ◽  
Power Efficiency ◽  
Business Owners ◽  
Refrigeration System ◽  
Operation Process ◽  
Refrigeration Unit ◽  
Industrial Refrigeration ◽  
Night Period ◽  
Dry Cooling Tower ◽  
Processing Enterprise

Rising prices on power supply are forcing business owners to search the ways of operating costs reducing. Refrigeration system in the food industry is a major source of power consumption. The utilization of cold accumulation systems allows reducing of refrigeration unit power consumption. In this paper the refrigeration system with a system of cold accumulation and dry cooling tower is considered. The possibility of power consumption reducing due to the organization of the enterprise refrigeration system operation process in the night period according to electricity multiple tariffs has been analyzed.

scholarly journals Gas Heating Mechanisms in Atmospheric Pressure Helium Dielectric-Barrier Discharges Driven by a kHz Power Source

2020 ◽  
Vol 10 (21) ◽  
pp. 7583
Author(s):  
Kun-Mo Lin ◽  
Kai-Cheng Wang ◽  
Yao-Sheng Chang ◽  
Shun-Yu Chuang
Keyword(s):  
Power Consumption ◽  
Joule Heating ◽  
Atmospheric Pressure ◽  
Power Efficiency ◽  
Rotational Temperature ◽  
Elastic Collision ◽  
Dielectric Barrier Discharges ◽  
Dielectric Barrier ◽  
Heating Source ◽  
Barrier Discharges

The present work investigates contributions of different heating mechanisms and power efficiency of atmospheric-pressure helium dielectric-barrier discharges (APHeDBDs) containing a small amount of N2 for temperature measurements by developing the numerical methodology combining the one-dimensional (1D) plasma fluid model (PFM) and 3D gas flow model (GFM) with simulated results validated by measurements including the discharge power consumption and temperature distribution. The discharge dynamics are modeled by the 1D PFM for evaluating the average heating source considering elastic collision, ion Joule heating, and exothermic reactions as the source term of energy equation solved in the 3D GFM. The simulated current density reaches 29 A m−2 which is close to that measured as 35 A m−2. The simulated power consumption is 2.0 W which is in good agreement with the average measured power consumption as 2.1 W. The simulated average gas temperature in the reactive zone is around 346 K which is also close to the rotational temperature determined. The analysis shows that elastic collision and ion Joule heating are dominant heating mechanisms contributing 23.9% and 65.8% to the heating source, respectively. Among ion species, N2+ and N4+ are dominant species contributing 44.1% and 50.7% to the heating source of ion Joule heating, respectively. The simulated average total heating source is around 5.6 × 105 W m−3 with the maximum reaching 3.5 × 106 W m−3 in the sheath region due to the contribution of ion Joule heating.

scholarly journals Toward Green Sensor Field by Optimizing Power Efficiency Using D-Policy M/G/1 Queuing Systems

2013 ◽  
Vol 9 (3) ◽  
pp. 241-260 ◽  
Author(s):  
Fuu-Cheng Jiang ◽  
Hsiang-Wei Wu ◽  
Fang-Yi Leu ◽  
Chao-Tung Yang
Keyword(s):  
Sensor Networks ◽  
Power Consumption ◽  
Power Efficiency ◽  
Ieee 802.15.4 ◽  
Power Saving ◽  
Rechargeable Batteries ◽  
Sensor Nodes ◽  
Traffic Load ◽  
Mathematical Framework ◽  
Sensor Field

Power efficiency is a crucially important issue in the IEEE 802.15.4/ZigBee sensor networks (ZSNs) for majority of sensor nodes equipped with non-rechargeable batteries. To increase the lifetime of sensor networks, each node must optimize power consumption as possible. Among open literatures, much research works have focused on how to optimally increase the probability of sleeping states using multifarious wake-up strategies. Making things different, in this article, we propose a novel optimization framework for alleviating power consumption of sensor node with the D-policy M/G/1 queuing approach. Toward green sensor field, the proposed power-saving technique can be applied to prolong the lifetime of ZSN economically and effectively. For the proposed data aggregation model, mathematical framework on performance measures has been formulated. Data simulation using MATLAB tool has been conducted for exploring the feasibility of the proposed approach. And also we analyze the average traffic load per node for tree-based ZSN. Focusing on ZigBee routers deployed at the innermost shell of ZSN, network simulation results validate that the proposed approach indeed provides a feasibly cost-effective approach for prolonging lifetime of ZSNs.

Rack Server Solution in Data Center

2015 ◽  
Author(s):  
Sheng Kang ◽  
Guofeng Chen ◽  
Chun Wang ◽  
Ruiquan Ding ◽  
Jiajun Zhang ◽  
...  
Keyword(s):  
Power Consumption ◽  
Low Power ◽  
Power Supply ◽  
Data Center ◽  
Power Efficiency ◽  
High Performance ◽  
High Efficiency ◽  
High Growth ◽  
General Purpose ◽  
Power Supplies

With the advent of big data and cloud computing solutions, enterprise demand for servers is increasing. There is especially high growth for Intel based x86 server platforms. Today’s datacenters are in constant pursuit of high performance/high availability computing solutions coupled with low power consumption and low heat generation and the ability to manage all of this through advanced telemetry data gathering. This paper showcases one such solution of an updated rack and server architecture that promises such improvements. The ability to manage server and data center power consumption and cooling more completely is critical in effectively managing datacenter costs and reducing the PUE in the data center. Traditional Intel based 1U and 2U form factor servers have existed in the data center for decades. These general purpose x86 server designs by the major OEM’s are, for all practical purposes, very similar in their power consumption and thermal output. Power supplies and thermal designs for server in the past have not been optimized for high efficiency. In addition, IT managers need to know more information about servers in order to optimize data center cooling and power use, an improved server/rack design needs to be built to take advantage of more efficient power supplies or PDU’s and more efficient means of cooling server compute resources than from traditional internal server fans. This is the constant pursuit of corporations looking at new ways to improving efficiency and gaining a competitive advantage. A new way to optimize power consumption and improve cooling is a complete redesign of the traditional server rack. Extracting internal server power supplies and server fans and centralizing these within the rack aims to achieve this goal. This type of design achieves an entirely new low power target by utilizing centralized, high efficiency PDU’s that power all servers within the rack. Cooling is improved by also utilizing large efficient rack based fans for airflow to all servers. Also, opening up the server design is to allow greater airflow across server components for improved cooling. This centralized power supply breaks through the traditional server power limits. Rack based PDU’s can adjust the power efficiency to a more optimum point. Combine this with the use of online + offline modes within one single power supply. Cold backup makes data center power to achieve optimal power efficiency. In addition, unifying the mechanical structure and thermal definitions within the rack solution for server cooling and PSU information allows IT to collect all server power and thermal information centrally for improved ease in analyzing and processing.

The Use of Ejector Refrigeration Systems for Turbine Inlet Air Cooling: A Thermodynamic and CFD Study

2007 ◽  
Author(s):  
Hany A. Al-Ansary
Keyword(s):  
Power Consumption ◽  
Power Output ◽  
Waste Heat ◽  
Evaporative Cooling ◽  
Published Data ◽  
Air Cooling ◽  
Refrigeration System ◽  
Compressor Blades ◽  
Cooling Systems ◽  
Turbine Inlet

Cooling turbine inlet air is a proven method of increasing turbine power output, especially during peak summer demand. It is estimated that turbine power output can increase by as much as 0.7% for every 1°C drop in inlet air temperature. Two inlet air cooling systems are widely used: evaporative cooling systems and chiller systems. Evaporative cooling is economical and uncomplicated, but its efficiency can significantly drop if the relative humidity is high. There is also a potential for excessive wear of compressor blades if water droplets are carried into the compressor section. On the other hand, chiller systems have the advantage of being independent of humidity and do not have the potential to cause damage to compressor blades. However, chiller systems consume power and cause a larger pressure drop than evaporative coolers. In this work, the possibility of using an ejector refrigeration system to cool turbine inlet air is explored. These systems are low-maintenance, fluid-driven, heat-operated devices that can use part of the turbine exhaust flow as the heat source for running the cycle. These systems require only pump power to feed liquid refrigerant to the vapor generator, making the power consumption potentially lower than conventional chiller systems. Using thermodynamic analysis, this paper compares the performance of ejector refrigeration systems with that of chiller systems based primarily on their power consumption. Performance characteristics for the ejector system are obtained through a CFD model that uses a real-gas model for R-134a. Published data on the performance of a commercial gas turbine is also considered. The power consumption of ejector refrigeration systems is found to be significantly smaller than that of vapor compression systems, with savings ranging from 19% to 80%. Power consumption is also found to be small compared to the boost in turbine power that is obtained. The percentage of waste heat needed to operate the ejector refrigeration system is found to be generally less than 25%.

Heat Transfer Analysis of Regenerative Thermo-Mechanical Refrigeration System

2020 ◽  
Author(s):  
Ahmad K. Sleiti ◽  
Mohammed Al-Khawaja
Keyword(s):  
Environmental Effects ◽  
Power Efficiency ◽  
Power Plants ◽  
Internal Combustion Engines ◽  
Waste Heat ◽  
Heat Transfer Analysis ◽  
Working Fluid ◽  
Refrigeration System ◽  
Renewable Energy Resources ◽  
Working Fluids

Abstract Refrigeration systems contribute to the critical environmental concerns including global warming and ozone depletion. It is necessary to develop new systems that use renewable energy resources and waste heat to perform the cooling function with eco-friendly working fluids. This improves the energy efficiency of the power systems and minimizes the harmful effects of conventional refrigeration systems. This paper introduces an analysis of a regenerative thermo-mechanical refrigeration system that is powered with renewable heat sources (solar, geothermal) or waste heat (from internal combustion engines, gas power plants, and steam power plants). The system operates at the supercritical conditions of the working fluids. The performance of the system is evaluated based on power efficiency, the COP, and the expander-compressor diameters. Also, a number of working fluids were compared with each other based on their performance and environmental effects. There is a trade-off between high-performance fluids and their environmental effects. Using R32 as a working fluid at Th = 150 °C and Tc1 = 40 °C, the system produces a cooling capacity of 1 kW with power efficiency of 10.23%, expander diameter of 53.12 mm and compressor diameter of 75.4mm. The regenerator increases the power efficiency by about 1%. However, the size of the regenerator is small (Dr = 6.5 mm, Lr = 142 mm].

Low Power Electronics for Square-Wave Piezoactuator Driving

2009 ◽  
Author(s):  
G. Biancuzzi ◽  
T. Lemke ◽  
F. Goldschmidtboeing ◽  
O. Ruthmann ◽  
H.-J. Schrag ◽  
...  
Keyword(s):  
Power Consumption ◽  
Low Power ◽  
Power Efficiency ◽  
Low Voltage ◽  
Power Converter ◽  
Driving Voltage ◽  
Output Stage ◽  
Maximum Displacement ◽  
Artificial Sphincter ◽  
Charge Recovery

The German Artificial Sphincter System (GASS) project aims at the development of an implantable sphincter prosthesis driven by a micropump. During the last few years the feasibility of the concept has been proven. At present our team’s effort is focused on the compliance to safety regulations and on a very low power consumption of the system as a whole. Therefore a low-voltage multilayer piezoactuator has been developed to reduce the driving voltage of the micropump from approximately 300 Vpp to 40 Vpp. Doing so, the driving voltage is within the limits set by the regulations for active implants. The operation of the micropump at lower voltages, achieved using multilayer piezoactuators, has already resulted in a much better power efficiency. Nevertheless, in order to further reduce power consumption, we have also developed an innovative driving technique that we are going to describe and compare to other driving systems. A direct switching circuit has been developed where the buffer capacitor of the step-up converter has been replaced by the equivalent capacitance of the actuator itself. This avoids the switching of the buffer capacitor to the actuator, which would result in a very low efficiency. Usually, a piezoactuator needs a bipolar voltage drive to achieve maximum displacement. In our concept, the voltage inversion across the actuator is done using an h-bridge circuit, allowing the employment of one step-up converter only. The charge stored in the actuator is then partially recovered by means of a step-down converter which stores back the energy at the battery voltage level. The power consumption measurements of our concept are compared to a conventional driving output stage and also with inductive charge recovery circuits. In particular, the main advantage, compared to the latter systems, consists in the small inductors needed for the power converter. Other charge recovery techniques require very big inductors in order to have a significant power reduction with the capacitive loads we use in our application. With our design we will be able to achieve approximately 55% reduction in power consumption compared to the simplest conventional driver and 15% reduction compared to a charge recovery driver.

scholarly journals Power-Efficient Driver Circuit for Piezo Electric Actuator with Passive Charge Recovery

Energies ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2866 ◽  
Author(s):  
Takashi Ozaki ◽  
Norikazu Ohta
Keyword(s):  
Power Consumption ◽  
Piezoelectric Actuator ◽  
Power Efficiency ◽  
Parasitic Capacitance ◽  
Passive Components ◽  
Power Efficient ◽  
Electric Actuator ◽  
Driver Circuit ◽  
Aerial Vehicle ◽  
Charge Recovery

Piezoelectric actuation is a promising principle for insect-scaled robots. A major concern while utilizing a piezoelectric actuator is energy loss due to its parasitic capacitance. In this paper, we propose a new concept to recover the charge stored in the parasitic capacitance; it requires only three additional lightweight passive components: two diodes and a resistor. The advantages of our concept are its small additional mass and simple operating procedure compared with existing charge recovery circuits. We provided a guideline for selecting a resistor using a simplified theoretical model and found that half of the charge can be recovered by employing a resistor that has a resistance sufficiently larger than the forward resistance of the additional diode. In addition, we experimentally demonstrated the concept. With a capacitive load (as a replacement for the piezoelectric actuator), it was successfully observed that the proposed concept decreased the power consumption to 58% of that in a circuit without charge recovery. Considering micro aerial vehicle (MAV) applications, we measured the lift-to-power efficiency of a flapping wing piezoelectric actuator by applying the proposed concept. The lift force was not affected by charge recovery; however, the power consumption was reduced. As a result, the efficiency was improved to 30.0%. We expect that the proposed circuit will contribute to the advancement of energy-saving microrobotics.

scholarly journals Improving the Energy Efficiency of Industrial Refrigeration Systems by Means of Data-Driven Load Management

Processes ◽  
2020 ◽  
Vol 8 (9) ◽  
pp. 1106
Author(s):  
Josep Cirera ◽  
Jesus A. Carino ◽  
Daniel Zurita ◽  
Juan A. Ortega
Keyword(s):  
Food Industry ◽  
Operation Time ◽  
Data Driven ◽  
Load Management ◽  
Common Denominator ◽  
Refrigeration System ◽  
The Individual ◽  
Industrial Refrigeration ◽  
Electrical Consumption ◽  
New Industry

A common denominator in the vast majority of processes in the food industry is refrigeration. Such systems guarantee the quality and the requisites of the final product at the expense of high amounts of energy. In this regard, the new Industry 4.0 framework provides the required data to develop new data-based methodologies to reduce such energy expenditure concern. Focusing in this issue, this paper proposes a data-driven methodology which improves the efficiency of the refrigeration systems acting on the load side. The solution approaches the problem with a novel load management methodology that considers the estimation of the individual load consumption and the necessary robustness to be applicable in highly variable industrial environments. Thus, the refrigeration system efficiency can be enhanced while maintaining the product in the desired conditions. The experimental results of the methodology demonstrate the ability to reduce the electrical consumption of the compressors by 17% as well as a 77% reduction in the operation time of two compressors working in parallel, a fact that enlarges the machines life. Furthermore, these promising savings are obtained without compromising the temperature requirements of each load.

Thermodynamic Analysis of a Solar Zeolite Refrigeration System

1985 ◽  
Vol 107 (3) ◽  
pp. 189-195 ◽  
Author(s):  
S. C. Chang ◽  
J. A. Roux
Keyword(s):  
Ambient Temperature ◽  
Water Absorption ◽  
System Performance ◽  
Solar Collector ◽  
Design Parameters ◽  
Absorption Refrigeration ◽  
Refrigeration System ◽  
Absorption Data ◽  
Refrigeration Unit ◽  
Determine System

A solar zeolite-water absorption refrigeration unit was studied. Thermodynamic expressions were derived to predict the system performance. The operating range and optimum design parameters for the zeolite system were determined. The main parameters governing performance were: solar collector type, ambient temperature, and absorber properties. Results are shown for various solar collector types and various zeolite types. A desorption initiation temperature is shown to exist. The analysis is not based on empirical heat of absorption data, but rather on a zeolite properties relationship (log Pv versus 1/Tz) to determine system performance.

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