scholarly journals A New Step in the Optimization of the Chambadal Model of the Carnot Engine

Entropy ◽  
2022 ◽  
Vol 24 (1) ◽  
pp. 84
Author(s):  
Michel Feidt ◽  
Monica Costea
Keyword(s):  
Energy Efficiency ◽  
Entropy Production ◽  
Sequential Optimization

This paper presents a new step in the optimization of the Chambadal model of the Carnot engine. It allows a sequential optimization of a model with internal irreversibilities. The optimization is performed successively with respect to various objectives (e.g., energy, efficiency, or power when introducing the duration of the cycle). New complementary results are reported, generalizing those recently published in the literature. In addition, the new concept of entropy production action is proposed. This concept induces new optimums concerning energy and power in the presence of internal irreversibilities inversely proportional to the cycle or transformation durations. This promising approach is related to applications but also to fundamental aspects.

scholarly journals User Association and Power Control for Energy Efficiency Maximization in M2M-Enabled Uplink Heterogeneous Networks with NOMA

Sensors ◽  
2019 ◽  
Vol 19 (23) ◽  
pp. 5307 ◽  
Author(s):  
Shuang Zhang ◽  
Guixia Kang
Keyword(s):  
Energy Efficiency ◽  
Power Control ◽  
Heterogeneous Networks ◽  
Base Station ◽  
Sequential Optimization ◽  
User Association ◽  
Decode And Forward ◽  
Vast Number ◽  
Machine Type ◽  
Machine Type Communication

To support a vast number of devices with less energy consumption, we propose a new user association and power control scheme for machine to machine enabled heterogeneous networks with non-orthogonal multiple access (NOMA), where a mobile user (MU) acting as a machine-type communication gateway can decode and forward both the information of machine-type communication devices and its own data to the base station (BS) directly. MU association and power control are jointly considered in the formulated as optimization problem for energy efficiency (EE) maximization under the constraints of minimum data rate requirements of MUs. A many-to-one MU association matching algorithm is firstly proposed based on the theory of matching game. By taking swap matching operations among MUs, BSs, and sub-channels, the original problem can be solved by dealing with the EE maximization for each sub-channel. Then, two power control algorithms are proposed, where the tools of sequential optimization, fractional programming, and exhaustive search have been employed. Simulation results are provided to demonstrate the optimality properties of our algorithms under different parameter settings.

scholarly journals Assessment of the Effect of Energy Consumption on Trajectory Improvement for a Car-like Robot

Robotica ◽  
2019 ◽  
Vol 37 (11) ◽  
pp. 1998-2009 ◽  
Author(s):  
Francisco Valero ◽  
Francisco Rubio ◽  
Carlos Llopis-Albert
Keyword(s):  
Energy Efficiency ◽  
Energy Consumption ◽  
Mobile Robot ◽  
Optimization Algorithm ◽  
Random Distribution ◽  
Lower Cost ◽  
Maximum Velocity ◽  
Optimization Techniques ◽  
Sequential Optimization ◽  
Inertial Parameters

SummaryReducing the energy consumed by a car-like mobile robot makes it possible to move at a lower cost, yet it takes more working time. This paper proposes an optimization algorithm for trajectories with optimal times and analyzes the consequences of restricting the energy consumed on the trajectory obtained for a car-like robot. When modeling the dynamic behavior of the vehicle, it is necessary to consider its inertial parameters, the behavior of the motor, and the basic properties of the tire in its interaction with the ground. To obtain collision-free, minimum-time trajectories quadratic sequential optimization techniques are used, where the objective function is the time taken by the robot to move between two given configurations. This is subject to constraints relating to the vehicle and tires as well as the energy consumed, which is the basis for this paper. We work with a real random distribution of consumed energy values following a normal Gaussian distribution in order to analyze its influence on the trajectories obtained by the vehicle. The energy consumed, the time taken, the maximum velocity reached, and the distance traveled are analyzed in order to characterize the properties of the trajectories obtained. The proposed algorithm has been applied to 101 examples, showing that the computational times needed to obtain the solutions are always lower than those required to realize the trajectories. The results obtained allow us to reach conclusions about the energy efficiency of the trajectories.

scholarly journals The Nasal Geometry of the Reindeer Gives Energy-Efficient Respiration

2017 ◽  
Vol 42 (1) ◽  
Author(s):  
Elisa Magnanelli ◽  
Øivind Wilhelmsen ◽  
Mario Acquarone ◽  
Lars P. Folkow ◽  
Signe Kjelstrup
Keyword(s):  
Energy Efficiency ◽  
Entropy Production ◽  
Energy Efficient ◽  
The Arctic ◽  
Water Recovery ◽  
Total Entropy ◽  
Breathing Cycle ◽  
Reference Case ◽  
Heat And Mass Exchange ◽  
Total Entropy Production

AbstractReindeer in the arctic region live under very harsh conditions and may face temperatures below 233 K. Therefore, efficient conservation of body heat and water is important for their survival. Alongside their insulating fur, the reindeer nasal mechanism for heat and mass exchange during respiration plays a fundamental role. We present a dynamic model to describe the heat and mass transport that takes place inside the reindeer nose, where we account for the complicated geometrical structure of the subsystems that are part of the nose. The model correctly captures the trend in experimental data for the temperature, heat and water recovery in the reindeer nose during respiration. As a reference case, we model a nose with a simple cylindrical-like geometry, where the total volume and contact area are the same as those determined in the reindeer nose. A comparison of the reindeer nose with the reference case shows that the nose geometry has a large influence on the velocity, temperature and water content of the air inside the nose. For all investigated cases, we find that the total entropy production during a breathing cycle is lower for the reindeer nose than for the reference case. The same trend is observed for the total energy consumption. The reduction in the total entropy production caused by the complicated geometry is higher (up to -20 %) at more extreme ambient conditions, when energy efficiency is presumably more important for the maintenance of energy balance in the animal. In the literature, a hypothesis has been proposed, which states that the most energy-efficient design of a system is characterized by equipartition of the entropy production. In agreement with this hypothesis, we find that the local entropy production during a breathing cycle is significantly more uniform for the reindeer nose than for the reference case. This suggests that natural selection has favored designs that give uniform entropy production when energy efficiency is an issue. Animals living in the harsh arctic climate, such as the reindeer, can therefore serve as inspiration for a novel industrial design with increased efficiency.

Drying and heating of scrap metal at steelmaking: industrial safety, economics, ecology

2020 ◽  
Vol 76 (12) ◽  
pp. 1353-1258
Author(s):  
V. A. Spirin ◽  
V. E. Nikol’skii ◽  
D. V. Vokhmintsev ◽  
A. A. Moiseev ◽  
P. G. Smirnov ◽  
...  
Keyword(s):  
Energy Efficiency ◽  
High Efficiency ◽  
Steel Production ◽  
Scrap Metal ◽  
Industrial Safety ◽  
Technical Solution ◽  
Metal Charge ◽  
Basic Task ◽  
Scrap Heating ◽  
Winter Time

At steel production based on scrap metal utilization, the scrap heating before charging into a melting facility is an important way of energy efficiency increase and ecological parameters improving. In winter time scrap metal charging with ice inclusions into a metal melt can result in a considerable damage of equipment and even accidents. Therefore, scrap preliminary drying is necessary to provide industrial safety. It was shown, that in countries with warm and low-snow climate with no risk of scrap metal icing up during its transportation and storing in the open air, the basic task being solved at the scrap drying is an increase of energy efficiency of steelmaking. InRussiathe scrap metal drying first of all provides the safety of the process and next - energy saving. Existing technologies of scrap metal drying and heating considered, as well as advantages and drawbacks of technical solutions used at Russian steel plants. In winter time during scrap metal heating at conveyers (Consteel process) hot gases penetrate not effectively into its mass, the heat is not enough for evaporation of wetness in the metal charge. At scrap heating by the furnace gases, a problem of dioxines emissions elimination arises. Application of shaft heaters results in high efficiency of scrap heating. However, under conditions of Russian winter the upper scrap layers are not always heated higher 0 °С and after getting into a furnace bath the upper scrap layers cause periodical vapor explosions. The shaft heaters create optimal conditions for dioxines formation, which emit into atmosphere. It was shown, that accounting Russian economic and nature conditions, the metal charge drying and heating in modified charging buckets by the heat of burnt natural gas or other additional fuel is optimal. The proposed technical solution enables to burnt off organic impurities ecologically safely, to melt down ice, to evaporate the wetness in the scrap as well as to heat the charge as enough as the charging logistics enables it. The method was implemented at several Russian steel plants. Technical and economical indices of scrap metal drying in buckets under conditions of EAF-based shop, containing two furnaces ДСП-100, presented.

Perspectives and Regulation of the Russian Market for Project-based Transactions under the Kyoto Protocol

2008 ◽  
pp. 108-125
Author(s):  
K. Zavodov
Keyword(s):  
Energy Efficiency ◽  
Market Mechanism ◽  
Point Of View ◽  
Market Regulation ◽  
Foreign Investments ◽  
Russian Market ◽  
Increase Energy Efficiency ◽  
New Form ◽  
Contract Structure ◽  
Carbon Fund

Project-based transactions (PBTs) are a market mechanism of attracting foreign investments in order to abate greenhouse gas emissions and increase energy efficiency of the country’s enterprises. The article provides a classification and analyzes advantages and drawbacks of PBTs from the point of view of a host country. The main trends and factors determining the dynamics of the PBT market are described. Given that Russia currently lags behind the leaders of the PBT market, an incorporation of a state carbon fund is put forward with an aim of channelling PBTs through it. This paper proposes a form of PBT market regulation by incorporating an option mechanism into the contract structure of a transaction. A comparison of the new form of regulation with the tools that are currently in use in Russia and other countries demonstrates its greater economic efficiency under uncertainty.

Fiscal deduction in Italy for energy efficiency in residential buildings: Some insights

2017 ◽  
pp. 15-29
Author(s):  
Domenico Prisinzano ◽  
Alessandro Federici ◽  
Amalia Martelli ◽  
Chiara Martini ◽  
Roberto Moneta
Keyword(s):  
Energy Efficiency ◽  
Residential Buildings
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