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

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.

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Improvements in CO2 Booster Architectures with Different Economizer Arrangements

Energies ◽

10.3390/en13051271 ◽

2020 ◽

Vol 13 (5) ◽

pp. 1271 ◽

Cited By ~ 4

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%.

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Energy efficiency of modernization of translucent building envelope structures

Energy Engineering and Control Systems ◽

10.23939/jeecs2021.02.087 ◽

2021 ◽

Vol 7 (2) ◽

pp. 87-96

Author(s):

Vitalii Burmaka ◽

◽

Mykola Tarasenko ◽

Kateryna Kozak ◽

Oleksandr Burmaka ◽

...

Keyword(s):

Energy Efficiency ◽

Energy Savings ◽

Electricity Consumption ◽

Building Envelope ◽

Heat Energy ◽

Economic Feasibility ◽

Thermal Parameters ◽

Energy Losses ◽

Heating Period ◽

Cooling Period

The article focuses on determining the energy efficiency of the translucent structures of building envelope (TSBE) use with different lighting and thermal parameters. The expediency of replacing TSBE with more modern ones with higher thermal resistance and lower solar radiations relative penetration coefficient (SRRPC) is considered. The comparison was made taking into account the influence of TSBE parameters on electricity consumption in the office premises on the compensation of heat energy losses, as well as its savings due to the receipt of solar radiation during the heating period, the removal of excess heat during the cooling period and energy savings through the use of daylight during a year. It was found that despite the smaller glazing area and light-transmitting characteristics of configuration No. 3 (profile Veka Softline 82 with triple-glazed window 4Solar-16Ar-4-12Ar-4і), electricity savings when changing the configuration of TSBE No. 1 to No. 3 leads to energy savings of 31.7 kWh/yr with the TSBE area of 0.5 m2 to 419.5 kWh/yr at 6 m2, and when replacing configuration No2 by No3 – from 24.7 (STSBE = 0.5 m2) up to 397.2 (STSBE = 6 m2). This makes it possible to determine the energy and economic feasibility of TSBE modernization by installing metal-plastic structures with different lighting and thermal parameters.

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Energy efficiency of nonlinear domain decomposition methods

The International Journal of High Performance Computing Applications ◽

10.1177/1094342020953891 ◽

2020 ◽

pp. 109434202095389

Author(s):

Axel Klawonn ◽

Martin Lanser ◽

Oliver Rheinbach ◽

Gerhard Wellein ◽

Markus Wittmann

Keyword(s):

Energy Efficiency ◽

Domain Decomposition ◽

Newton’S Method ◽

Newton's Method ◽

Decomposition Method ◽

Energy Savings ◽

Domain Decomposition Method ◽

Nonlinear Problems ◽

Decomposition Methods ◽

Save Energy

A nonlinear domain decomposition (DD) solver is considered with respect to improved energy efficiency. In this method, nonlinear problems are solved using Newton’s method on the subdomains in parallel and in asynchronous iterations. The method is compared to the more standard Newton-Krylov approach, where a linear domain decomposition solver is applied to the overall nonlinear problem after linearization using Newton’s method. It is found that in the nonlinear domain decomposition method, making use of the asynchronicity, some processor cores can be set to sleep to save energy and to allow better use of the power and thermal budget. Energy savings on average for each socket up to 77% (due to the RAPL hardware counters) are observed compared to the more traditional Newton-Krylov approach, which is synchronous by design, using up to 5120 Intel Broadwell (Xeon E5-2630v4) cores. The total time to solution is not affected. On the contrary, remaining cores of the same processor may be able to go to turbo mode, thus reducing the total time to solution slightly. Last, we consider the same strategy for the ASPIN (Additive Schwarz Preconditioned Inexact Newton) nonlinear domain decomposition method and observe a similar potential to save energy.

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Integration of Natural and Artificial Light on Energy Efficiency of the Mega Bank Makassar Tower Building

EPI International Journal of Engineering ◽

10.25042/epi-ije.022021.10 ◽

2021 ◽

Vol 4 (1) ◽

pp. 71-80

Author(s):

Isty Cahyani Ismail ◽

Ramli Rahim ◽

Baharuddin Hamzah

Keyword(s):

Energy Efficiency ◽

Energy Consumption ◽

Light Intensity ◽

Energy Use ◽

Energy Savings ◽

Building Design ◽

Artificial Light ◽

Lighting System ◽

Lighting Systems ◽

Save Energy

One of the largest energy consumers in the world is buildings. The energy consumption comes from the lighting system. Energy use in buildings is generally 25% for lighting systems. The strategy used in building design is to reduce energy consumption while maintaining the best comfort in a building. The application of energy-saving concepts from the building sector is optimizing the lighting system by integrating natural and artificial lighting systems. This study aims to determine the light intensity in the integrated lighting system of natural and artificial manually and also to find out how much energy can be saved with the integrated lighting system manually. The research location is at the Mega Bank Makassar Tower Building. The research sample was selected by purposive sampling and the sixth floor was chosen as the research location. In this study, simulations were carried out using the DIAlux 4.13 program to integrate natural and artificial light and to calculate the amount of energy efficiency in the workspace. To obtain optimal light intensity and energy savings, a simulation was carried out by turning off half the light points in the workspace, especially the light points around the building openings. The simulation results show that the average integrated lighting quality meets the minimum lighting requirements and can save energy usage by up to 50%. Keywords: energy efficiency; integration lighting; workspace

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Modeling of Energy Savings Performed by a Barbecue Oven Isolated with Terracotta Bricks

Physical Science International Journal ◽

10.9734/psij/2020/v24i530190 ◽

2020 ◽

pp. 8-21

Author(s):

Gaël Lassina Sawadogo ◽

Serge Wendsida Igo ◽

Abdoulaye Compaore ◽

Drissa Ouedraogo ◽

David Namoano ◽

...

Keyword(s):

Energy Efficiency ◽

Energy Balance ◽

Finite Differences ◽

Energy Savings ◽

Numerical Study ◽

Numerical Results ◽

Implicit Scheme ◽

Energy Losses ◽

Nodal Method ◽

Transfer Equations

This work is devoted to a numerical study of the energy savings achieved by an oven insulated with terracotta bricks compared to an uninsulated oven. The numerical methodology is based on the nodal method and the transfer equations were obtained by making an energy balance on each node. The equations were then discretized using an implicit scheme with finite differences and solved by the Gauss algorithm. Numerical results validated by the experiment show that the insulation of the oven with terracotta bricks considerably reduces the energy losses through the walls, but the reduction level varies according to the thickness of the bricks. The optimal thicknesses of the bricks are between 3 and 4 cm, which corresponds to energy savings of between 60 to 70% compared to the uninsulated oven. The energy saved increases the energy efficiency of the oven from 15-17% to 25-29%.

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Multi-Point-of-View Energy Loss Analysis in a Refuse Truck Hydraulic System

Energies ◽

10.3390/en14092707 ◽

2021 ◽

Vol 14 (9) ◽

pp. 2707

Author(s):

Luis Javier Berne ◽

Gustavo Raush ◽

Pedro Javier Gamez-Montero ◽

Pedro Roquet ◽

Esteban Codina

Keyword(s):

Energy Efficiency ◽

Hydraulic System ◽

Energy Demand ◽

Combustion Engine ◽

Point Of View ◽

Energy Losses ◽

Hydraulic Systems ◽

Hydraulic Machines ◽

Points Of View ◽

The Individual

In recent years, much research has focused on reducing the power consumption of mobile hydraulic machines due to rising fuel costs, regulations on combustion engine emissions and the need to reduce the size and weight of the storage devices in hybrid drives. Current approaches to improve the energy efficiency of a hydraulic system can be classified into four basic groups: reduction of the energy demand, recovery of part of the supplied energy (ERS systems), regeneration of part of the supplied energy and reuse of the recovered and regenerated energy (hybrid systems). Today’s mobile hydraulic systems are often complex, perform different tasks and work under different load conditions, which makes it difficult to analyse energy losses. A study of the energy losses of a hydraulic system from different points of view, such as an energy balance for a complete machine cycle, an analysis of the individual cycle phases and a power analysis for the different operation quadrants of the actuators, can give an global picture of the energy losses, being very useful to rate its energy efficiency, identify main power losses and decide which of the different energy-saving techniques to apply. This paper describes the data collection process, its analysis from various points of view and the summary of the results in easy to understand charts as useful tools to identify and quantify the main energy losses. Only system architecture losses are considered. Losses in the ICE engine or the electric motor, hydraulic pump losses and mechanical losses are outside the scope of this study.

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Experimental Study on Energy Efficiency of Two-Cylinder Direct Driven Hydraulic System in a Large-Scale Test Bench

10.1115/fpmc2021-68797 ◽

2021 ◽

Author(s):

Robert Hermansson ◽

Ville Närvänen ◽

Jyrki Kajaste ◽

Olof Calonius ◽

Matti Pietola ◽

...

Keyword(s):

Energy Efficiency ◽

Electric Motor ◽

Hydraulic System ◽

Large Scale ◽

Test Bench ◽

Position Control ◽

Input Power ◽

Total Efficiency ◽

Servo Motor ◽

High Dependency

Abstract In this research the energy efficiency of a pump controlled direct driven hydraulic (DDH) system is experimentally tested and analyzed. The test bench uses two cylinders’ cross-connection to rotate the middle joint of the 5-meter-long pivot arm which is loaded with unequal load of maximum 1685 kg. Originally the test bench is designed to study the application of DDH in the case of an articulated steering system, but in this research the system is treated as load lifting and load lowering application. The power pack of the test bench features a permanent magnet servo motor and a bent-axis, fixed-displacement hydraulic motor-pump unit. A separate charge pump circuit is attached, which also controls the servo motor and pump case temperature and takes care of fluid heat management as well as filtering. An extensive CAN-network is utilized for measurement and control. The motion of the test bench is driven with position control to give reproducible lifting and lowering cycles with different loads and velocities. Three motion cycles are executed involving three different loads, nine combinations in total, to study their effect on energy efficiency in load lifting and load lowering situations. Mechanical input power is measured between the electric motor and pump, hydraulic power is measured at the pump outlet and at the cylinder ports, and finally the mechanical output power is calculated for the cylinder-to-mechanical interface. Energy losses are determined as well as the overall energy efficiency of the hydraulic system. The research focuses on the hydraulic system and therefore the electric input power to the system and the regenerated electric power in load lowering is left out of the study. However, the regeneration potential in load lowering part of the cycles is measured as the available electric motor shaft power. In load lifting, the total energy efficiency of the hydraulic system was at its best at 82% when using the maximum additional load of 1685 kg and the lowest lifting velocity of 0.1 rad/s. Energy efficiency of load lowering was at its best in the same cycle with 77% of the energy recovered from the pump-motor’s shaft. High dependency on load and velocity was detected, because the total efficiency in lifting decreased to 44% with highest velocity (0.3 rad/s) and lowest load (445 kg). In lowering, during the same cycle, the total efficiency was −17%, meaning that gravity loading alone could not produce fast enough motion and that active input power was needed. In conclusion, very good energy efficiency could be achieved when operating against high enough loading. Operating at partial loads and with higher velocities will clearly reduce energy efficiency, emphasizing the need for careful dimensioning of all the power train components.

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What Factors Cause Weak Industrial Energy Management Practices?

Strategic Planning for Energy and the Environment ◽

10.13052/spee1048-4236.39145 ◽

2021 ◽

Author(s):

Naseha Wafa Qammar ◽

Zohaib Ur Rehman Afridi ◽

Shamaima Wafa Qammar ◽

Fazal Muhammad ◽

Farman Ali ◽

...

Keyword(s):

Energy Efficiency ◽

Energy Management ◽

Management Practices ◽

Energy Savings ◽

Service Providers ◽

Light Emitting Diode ◽

Steel Mill ◽

Industrial Energy ◽

Save Energy ◽

Awareness Level

The aim of this study is to investigate the ongoing energy management and energy efficiency practices in the industries of Peshawar division of Khyber Pakhtunkhwa, Pakistan. The outcomes of this research shows that Khazana Sugar Mills, Caliph Pharmaceutical, Naguman Flour Mill have no or low awareness of energy management practices (awareness level mainly includes barriers to energy efficiency and drivers for energy efficiency) except FF steel mill. The major paces observed in lacking the awareness are (1) “understanding level of staff and workers about energy savings due to energy management practices” (2) “interest level of top managers for energy management implementation” (3) “awareness level regarding energy efficiency” (4) “lack of technical competence” (5) “use of standardized procedures”. When the industry managers were inquired about the relationship with energy service providers it is found that there is absolute absence of energy engineers, relationship with energy consultancies and long-term energy strategy in all the industries. It was also found that there is lack of using renewable energy technologies in all industries as they were relying upon using the generators during the blackout hours. In terms of percentage, the energy saving factor of 36 kWh/day has also observed with the replacement of fluorescent tube lights with light emitting diode (LED) tube lights. Proper maintenance and energy management practices in the heating, ventilation and air conditioning system (HVAC) would also save energy in a significant amount. The study shows that there is an overall improvement factor of 4% to 8% if the inclusion of energy management and energy efficiency practices would have been applied in all the stated industries.

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Energy Saving Systems of Hydrostatic Drives for Ship Deck Machines

New Trends in Production Engineering ◽

10.2478/ntpe-2018-0063 ◽

2018 ◽

Vol 1 (1) ◽

pp. 507-514

Author(s):

Grzegorz Skorek

Keyword(s):

Energy Efficiency ◽

Control System ◽

Energy Saving ◽

Energy Savings ◽

Control Valve ◽

Total Efficiency ◽

Hydraulic Motor ◽

Pump Operation ◽

Variable Capacity ◽

Energy Behavior

Abstract A control system with a proportional directional throttling control valve or a directional control servo valve, controlling a cylinder (linear hydraulic motor) is used in the ship steering gear drive, in the controllable pitch propeller control, in the variable capacity pump control system for hydraulic deck equipment motors or fixed pitch propellers in small ships (for example ferries). Energy savings in a constant capacity pump operation can be achieved by means of overflow valve controlled by the oil outlet pressure between the directional throttling control valve and the cylinder. Although structural volumetric losses cannot be eliminated in such a system, but it is possible to reduce considerably structural pressure losses, mechanical losses and volumetric losses in the pump, and mechanical losses in the cylinder too. The paper discusses these energy savings using an earlier developed by Paszota mathematical model of losses in elements, the energy efficiency of the system and the operating range of the cylinder. The paper also presents a comparison of the energy behavior of two widespread structures of hydrostatic systems: a standard individual systems with a throttling steering fed by a constant capacity pump. Both system solutions are described and equations of the total efficiency η of the system are presented. Diagrams of energy efficiency of two hydraulic systems working at the same parameters of a speed and a load of hydraulic linear motor, which were different due to structure and ability of energy saving, were presented and compared.

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