scholarly journals Improvements in CO2 Booster Architectures with Different Economizer Arrangements

Energies ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1271 ◽  
Author(s):  
J. Catalán-Gil ◽  
L. Nebot-Andrés ◽  
D. Sánchez ◽  
R. Llopis ◽  
R. Cabello ◽  
...  
Keyword(s):  
Energy Efficiency ◽  
Energy Savings ◽  
Ambient Temperatures ◽  
Phase Out

CO2 transcritical booster architectures are widely analyzed to be applied in centralized commercial refrigeration plants in consonance with the irrevocable phase-out of HFCs. Most of these analyses show the limitations of CO2 cycles in terms of energy efficiency, especially in warm countries. From the literature, several improvements have been proposed to raise the booster efficiency in high ambient temperatures. The use of economizers is an interesting technique to reduce the temperature after the gas cooler and to improve the energy efficiency of transcritical CO2 cycles. The economizer cools down the high pressure’s line of CO2 by evaporating the same refrigerant extracted from another point of the facility. Depending on the extraction point, some configurations are possible. In this work, different booster architectures with economizers have been analyzed and compared. From the results, the combination of the economizer with the additional compressor allows obtaining energy savings of up to 8.5% in warm countries and up to 4% in cold countries with regard to the flash-by-pass arrangement and reduce the volumetric displacement required of the MT compressors by up to 37%.

Investigation of Thermal Effects in Direct Driven Hydraulic System for Off-Road Machinery

2016 ◽  
Author(s):  
Niko Karlén ◽  
Tatiana Minav ◽  
Matti Pietola
Keyword(s):  
Energy Efficiency ◽  
Hydraulic System ◽  
Energy Savings ◽  
Mechanical Energy ◽  
Hydraulic Model ◽  
Energy Losses ◽  
Total Efficiency ◽  
Ambient Temperatures ◽  
Wheel Loaders ◽  
Save Energy

Several types of off-road machinery, such as industrial trucks, forklifts, excavators, mobile cranes, and wheel loaders, are set to be operated in environments which can differ considerably from each other. This sets certain limits for both the drive transmissions and working hydraulics of these machines. The ambient temperature must be taken into account when selecting the hydraulic fluid since the viscosity and density of the fluid are changing at different operating temperatures. In addition to the temperature, energy efficiency can also be a problem in off-road machinery. In most off-road machines, diesel engines are employed to produce mechanical energy. However, there are energy losses during the working process, which causes inefficiency in produced energy. For better energy efficiency, hybridization in off-road machinery is an effective method to decrease fuel consumption and increase energy savings. One of the possible methods to save energy with hybrids is energy regeneration. However, it means that the basic hydraulic system inside off-road machinery needs to be modified. One solution for this is to utilize zonal or decentralized approach by means of direct driven hydraulic (DDH) system. This paper aims to investigate a DDH system for off-road machinery by means of modelling and analyzing the effect of the temperature. In the direct-driven hydraulic system, the actuator is controlled directly by the hydraulic pump which is operated by the electric motor. Specifically, it is a valveless closed-loop hydraulic system. Thus, there will be no energy losses caused by the valves, and the total efficiency is assumed to be significantly higher. In order to examine the DDH system, a thermo-hydraulic model was created. Additionally, a thermal camera was utilized in order to illustrate the temperature changes in the components of the DDH system. To reproduce the action of the system in different circumstances DDH system was run at different ambient temperatures, and the component temperatures in the system were measured and saved for the analysis. The thermo hydraulic model was proven capable to follow the general trend of heating up.

An Analysis of Actual Energy Savings in an Indian Cement Industry Through an Energy Efficiency Index

2012 ◽  
Vol 9 (8) ◽  
pp. 829-840 ◽  
Author(s):  
R. Saidur ◽  
M. T. Sambandam ◽  
M. Hasanuzzaman ◽  
D. Devaraj ◽  
S. Rajakarunakaran
Keyword(s):  
Energy Efficiency ◽  
Energy Savings ◽  
Efficiency Index ◽  
Cement Industry

scholarly journals Minimal Monitoring of Improvements in Energy Performance after Envelope Renovation in Subsidized Single Family Housing in Madrid

2020 ◽  
Vol 13 (1) ◽  
pp. 235
Author(s):  
Fernando Martín-Consuegra ◽  
Fernando de Frutos ◽  
Ignacio Oteiza ◽  
Carmen Alonso ◽  
Borja Frutos
Keyword(s):  
Energy Efficiency ◽  
Energy Savings ◽  
Low Cost ◽  
Energy Performance ◽  
Quality Parameters ◽  
Urban Setting ◽  
Single Family ◽  
Nineteen Fifties ◽  
Environment Quality ◽  
Urban Complex

This study quantified the improvement in energy efficiency following passive renovation of the thermal envelope in highly inefficient residential complexes on the outskirts of the city of Madrid. A case study was conducted of a single-family terrace housing, representative of the smallest size subsidized dwellings built in Spain for workers in the nineteen fifties and sixties. Two units of similar characteristics, one in its original state and the other renovated, were analyzed in detail against their urban setting with an experimental method proposed hereunder for simplified, minimal monitoring. The dwellings were compared on the grounds of indoor environment quality parameters recorded over a period covering both winter and summer months. That information was supplemented with an analysis of the energy consumption metered. The result was a low-cost, reasonably accurate measure of the improvements gained in the renovated unit. The monitoring output data were entered in a theoretical energy efficiency model for the entire neighborhood to obtain an estimate of the potential for energy savings if the entire urban complex were renovated.

scholarly journals Real-World Implementation of an ICT-Based Platform to Promote Energy Efficiency

Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2416
Author(s):  
Marina Dorokhova ◽  
Fernando Ribeiro ◽  
António Barbosa ◽  
João Viana ◽  
Filipe Soares ◽  
...  
Keyword(s):  
Energy Efficiency ◽  
Real World ◽  
Energy Savings ◽  
Quality Parameters ◽  
Horizon 2020 ◽  
Flexible Devices ◽  
Information And Communication ◽  
Energy Consuming ◽  
And Behavior ◽  
And Control

The energy efficiency requirements of most energy-consuming sectors have increased recently in response to climate change. For buildings, this means targeting both facility managers and building users with the aim of identifying potential energy savings and encouraging more energy-responsible behaviors. The Information and Communication Technology (ICT) platform developed in Horizon 2020 FEEdBACk project intends to fulfill these goals by enabling the optimization of energy consumption, generation, and storage and control of flexible devices without compromising comfort levels and indoor air quality parameters. This work aims to demonstrate the real-world implementation and functionality of the ICT platform composed of Load Disaggregation, Net Load Forecast, Occupancy Forecast, Automation Manager, and Behavior Predictor applications. Particularly, the results obtained by individual applications during the test phase are presented alongside the specific metrics used to evaluate their performance.

Energy efficiency and energy savings

Energy Policy ◽  
1994 ◽  
Vol 22 (12) ◽  
pp. 992 ◽  
Author(s):  
Leonard G. Brookes
Keyword(s):  
Energy Efficiency ◽  
Energy Savings

scholarly journals Renewable Energy Technologies for Energy Efficient Buildings: The Case of Kuwait

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4440
Author(s):  
Bader Alshuraiaan
Keyword(s):  
Energy Efficiency ◽  
Renewable Energy ◽  
Solar Energy ◽  
Energy Savings ◽  
Methodological Approach ◽  
Investment Efficiency ◽  
Renewable Energy Technologies ◽  
Energy Technologies ◽  
Energy Efficient Buildings ◽  
Proposed Model

The purpose of this study is to identify the most relevant renewable energy technologies for buildings and to assess the effectiveness of their implementation in the long term for Kuwait. Methods of analogies and comparisons were used to determine the features of energy efficiency based on the technologies under study. The study proposes the methodological approach to assessing the effectiveness of the introduction of renewable energy technologies, determining the direction of increasing the energy efficiency of buildings and the investment efficiency of introducing these technologies. Renewable energy efficiency analysis for buildings in Kuwait confirms that solar energy systems have been the most widely available for widespread use of solar energy over the past three years. An increasing level of energy efficiency with a decrease in the notional cost of increasing energy savings is characteristic of solar collectors with booster reflectors. The proposed model for assessing the level of energy saving provides an opportunity for economic justification of introducing renewable energy technology in buildings.

scholarly journals Dynamic Daylight Metrics for Electricity Savings in Offices: Window Size and Climate Smart Lighting Management

Energies ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 3143 ◽  
Author(s):  
Ignacio Acosta ◽  
Miguel Ángel Campano ◽  
Samuel Domínguez-Amarillo ◽  
Carmen Muñoz
Keyword(s):  
Energy Efficiency ◽  
Net Present Value ◽  
Energy Savings ◽  
Performance Metrics ◽  
Control Strategies ◽  
Window Size ◽  
Weather Conditions ◽  
Worst Case ◽  
Daylight Performance ◽  
Dynamic Metrics

Daylight performance metrics provide a promising approach for the design and optimization of lighting strategies in buildings and their management. Smart controls for electric lighting can reduce power consumption and promote visual comfort using different control strategies, based on affordable technologies and low building impact. The aim of this research is to assess the energy efficiency of these smart controls by means of dynamic daylight performance metrics, to determine suitable solutions based on the geometry of the architecture and the weather conditions. The analysis considers different room dimensions, with variable window size and two mean surface reflectance values. DaySim 3.1 lighting software provides the simulations for the study, determining the necessary quantification of dynamic metrics to evaluate the usefulness of the proposed smart controls and their impact on energy efficiency. The validation of dynamic metrics is carried out by monitoring a mesh of illuminance-meters in test cells throughout one year. The results showed that, for most rooms more than 3.00 m deep, smart controls achieve worthwhile energy savings and a low payback period, regardless of weather conditions and for worst-case situations. It is also concluded that dimming systems provide a higher net present value and allow the use of smaller window size than other control solutions.

scholarly journals DEVELOPMENT OF A NEW CO2-BASED DEMAND-CONTROLLED VENTILATION STRATEGY USING ENERGYPLUS

2017 ◽  
Author(s):  
Behrang Chenari ◽  
Francisco Bispo Lamas ◽  
Adélio Rodrigues Gaspar ◽  
Manuel Gameiro da Silva
Keyword(s):  
Energy Efficiency ◽  
Indoor Air ◽  
Energy Use ◽  
Energy Savings ◽  
Environmental Condition ◽  
Ventilation Strategy ◽  
Controlled Ventilation ◽  
New Strategy ◽  
Demand Controlled Ventilation ◽  
Air Conditioning Systems

A significant amount of energy is being used by ventilation and air conditioning systems to maintain the indoor environmental condition in a satisfactory and comfortable level. Many buildings, either new or existing (throughout their renovation process) are subjected to energy efficiency requirements but these must not be in the expenses of indoor environmental conditions. For instance, indoor air quality (IAQ) has to be considered while improving energy efficiency, otherwise occupants might be exposed to inappropriate indoor environment.Demand-controlled ventilation (DCV) is a method that provides comfortable IAQ level with lowest energy use. In this paper, the main objective is developing a new CO2-based DCV strategy and simulating it using EnergyPlus. The IAQ and energy consumption associated to this strategy have been compared with the results of CO2-based DCV strategies previously developed by the same authors in another article. The comparison shows that the new strategy performs better, both in energy use and IAQ. The recorded energy savings ranged between 6-14% comparing with the previously developed strategies while IAQ slightly improved.

scholarly journals Can We Regulate Our Way to Energy Efficiency? Product Standards as Climate Policy

2018 ◽  
Author(s):  
Noah M. Sachs
Keyword(s):  
Energy Efficiency ◽  
Financial Incentives ◽  
Information Disclosure ◽  
Energy Demand ◽  
Energy Savings ◽  
The United States ◽  
Vital Role ◽  
Political Support ◽  
Carbon Taxes ◽  
Regulatory Approach

In this Article, I demonstrate that the regulatory strategy for energy efficiency is working. Although information disclosure, financial incentives, and other softer alternatives to regulation play a vital role in reducing energy demand, these should be viewed as complements to efficiency regulation, rather than replacements. The regulatory approach has led to substantial cost and energy savings in the past, it has enjoyed bipartisan political support, and it targets products and behaviors that are difficult to address through other policy tools. Given the politics of climate change in the United States, which make federal carbon taxes or a cap-and-trade system infeasible, the regulatory option should be expanded, not abandoned.

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