scholarly journals Dynamics of the distribution mechanism with rocking tappet with roll

2019 ◽  
Vol 10 (3) ◽  
pp. 951
Author(s):  
Florian Ion Tiberiu Petrescu ◽  
Relly Victoria Virgil Petrescu

In this paper the authors present shortly an original method to make the dynamic synthesis of a mechanism with rotary cam and rotated tappet with roll, used with priority at the distribution mechanisms from the heat engines with internal combustion. This type of distribution can improve the changes of gases, and may decrease significantly the level of vibration, noises, and emissions. As long as we produce electricity and heat by burning fossil fuels is pointless to try to replace all thermal engines with electric motors, as loss of energy and pollution will be even larger. However, it is well to continuously improve the thermal engines, to reduce thus fuel consumption. At the heat engine with internal combustion a great loss of power is realized and by the distribution mechanism, reason for that we must try to improve the functionality of this mechanism. The dynamic synthesis of this type of distribution mechanism can be made shortly, by the Cartesian coordinates, but to determine these coordinates we need and some trigonometric parameters of the mechanism. Dynamics and forces of this distribution mechanism are presented as well. One introduce the dynamic coefficient D.

2015 ◽  
Vol 792 ◽  
pp. 542-545 ◽  
Author(s):  
V.V. Biryukov ◽  
M.V. Kalugin ◽  
A.O. Nevolina

Everyday the mankind consumes more and more energy, in this regard the stocks of traditional sources of this energy are decreased. Much attention has always been given to the problem of effective energy saving in transport. The environmental degradation is in parallel to the problem. The hybrid vehicle invention can be the solution of the problems given. The research considers the development and invention of the energy saving hybrid vehicle. The vehicle is driven by means of power station, the differential peculiarity of which is two energy sources usage and two types of engine, electric-powered and heat engine. In this paper the arrangements of combined and hybrid power stations for vehicles with heat-engines are developed. The key advantage of such vehicles is a fuel consumption reduction and the emission of harmful agents to the atmosphere.


Entropy ◽  
2021 ◽  
Vol 23 (4) ◽  
pp. 419
Author(s):  
Congzheng Qi ◽  
Zemin Ding ◽  
Lingen Chen ◽  
Yanlin Ge ◽  
Huijun Feng

Based on finite time thermodynamics, an irreversible combined thermal Brownian heat engine model is established in this paper. The model consists of two thermal Brownian heat engines which are operating in tandem with thermal contact with three heat reservoirs. The rates of heat transfer are finite between the heat engine and the reservoir. Considering the heat leakage and the losses caused by kinetic energy change of particles, the formulas of steady current, power output and efficiency are derived. The power output and efficiency of combined heat engine are smaller than that of single heat engine operating between reservoirs with same temperatures. When the potential filed is free from external load, the effects of asymmetry of the potential, barrier height and heat leakage on the performance of the combined heat engine are analyzed. When the potential field is free from external load, the effects of basic design parameters on the performance of the combined heat engine are analyzed. The optimal power and efficiency are obtained by optimizing the barrier heights of two heat engines. The optimal working regions are obtained. There is optimal temperature ratio which maximize the overall power output or efficiency. When the potential filed is subjected to external load, effect of external load is analyzed. The steady current decreases versus external load; the power output and efficiency are monotonically increasing versus external load.


Processes ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 996
Author(s):  
Venera Giurcan ◽  
Codina Movileanu ◽  
Adina Magdalena Musuc ◽  
Maria Mitu

Currently, the use of fossil fuels is very high and existing nature reserves are rapidly depleted. Therefore, researchers are turning their attention to find renewable fuels that have a low impact on the environment, to replace these fossil fuels. Biogas is a low-cost alternative, sustainable, renewable fuel existing worldwide. It can be produced by decomposition of vegetation or waste products of human and animal biological activity. This process is performed by microorganisms (such as methanogens and sulfate-reducing bacteria) by anaerobic digestion. Biogas can serve as a basis for heat and electricity production used for domestic heating and cooking. It can be also used to feed internal combustion engines, gas turbines, fuel cells, or cogeneration systems. In this paper, a comprehensive literature study regarding the laminar burning velocity of biogas-containing mixtures is presented. This study aims to characterize the use of biogas as IC (internal combustion) engine fuel, and to develop efficient safety recommendations and to predict and reduce the risk of fires and accidental explosions caused by biogas.


2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Yuto Ashida ◽  
Takahiro Sagawa

AbstractThe quest to identify the best heat engine has been at the center of science and technology. Considerable studies have so far revealed the potentials of nanoscale thermal machines to yield an enhanced thermodynamic efficiency in noninteracting regimes. However, the full benefit of many-body interactions is yet to be investigated; identifying the optimal interaction is a hard problem due to combinatorial explosion of the search space, which makes brute-force searches infeasible. We tackle this problem with developing a framework for reinforcement learning of network topology in interacting thermal systems. We find that the maximum possible values of the figure of merit and the power factor can be significantly enhanced by electron-electron interactions under nondegenerate single-electron levels with which, in the absence of interactions, the thermoelectric performance is quite low in general. This allows for an alternative strategy to design the best heat engines by optimizing interactions instead of single-electron levels. The versatility of the developed framework allows one to identify full potential of a broad range of nanoscale systems in terms of multiple objectives.


Entropy ◽  
2021 ◽  
Vol 23 (7) ◽  
pp. 860
Author(s):  
Ivan R. Kennedy ◽  
Migdat Hodzic

Despite the remarkable success of Carnot’s heat engine cycle in founding the discipline of thermodynamics two centuries ago, false viewpoints of his use of the caloric theory in the cycle linger, limiting his legacy. An action revision of the Carnot cycle can correct this, showing that the heat flow powering external mechanical work is compensated internally with configurational changes in the thermodynamic or Gibbs potential of the working fluid, differing in each stage of the cycle quantified by Carnot as caloric. Action (@) is a property of state having the same physical dimensions as angular momentum (mrv = mr2ω). However, this property is scalar rather than vectorial, including a dimensionless phase angle (@ = mr2ωδφ). We have recently confirmed with atmospheric gases that their entropy is a logarithmic function of the relative vibrational, rotational, and translational action ratios with Planck’s quantum of action ħ. The Carnot principle shows that the maximum rate of work (puissance motrice) possible from the reversible cycle is controlled by the difference in temperature of the hot source and the cold sink: the colder the better. This temperature difference between the source and the sink also controls the isothermal variations of the Gibbs potential of the working fluid, which Carnot identified as reversible temperature-dependent but unequal caloric exchanges. Importantly, the engine’s inertia ensures that heat from work performed adiabatically in the expansion phase is all restored to the working fluid during the adiabatic recompression, less the net work performed. This allows both the energy and the thermodynamic potential to return to the same values at the beginning of each cycle, which is a point strongly emphasized by Carnot. Our action revision equates Carnot’s calorique, or the non-sensible heat later described by Clausius as ‘work-heat’, exclusively to negative Gibbs energy (−G) or quantum field energy. This action field complements the sensible energy or vis-viva heat as molecular kinetic motion, and its recognition should have significance for designing more efficient heat engines or better understanding of the heat engine powering the Earth’s climates.


Entropy ◽  
2018 ◽  
Vol 20 (11) ◽  
pp. 865 ◽  
Author(s):  
Julian Gonzalez-Ayala ◽  
Moises Santillán ◽  
Maria Santos ◽  
Antonio Calvo Hernández ◽  
José Mateos Roco

Local stability of maximum power and maximum compromise (Omega) operation regimes dynamic evolution for a low-dissipation heat engine is analyzed. The thermodynamic behavior of trajectories to the stationary state, after perturbing the operation regime, display a trade-off between stability, entropy production, efficiency and power output. This allows considering stability and optimization as connected pieces of a single phenomenon. Trajectories inside the basin of attraction display the smallest entropy drops. Additionally, it was found that time constraints, related with irreversible and endoreversible behaviors, influence the thermodynamic evolution of relaxation trajectories. The behavior of the evolution in terms of the symmetries of the model and the applied thermal gradients was analyzed.


2020 ◽  
Vol 60 (1) ◽  
pp. 123-129
Author(s):  
M.G. Matache ◽  
M. Cristea ◽  
I. Găgeanu ◽  
A. Zapciu ◽  
E. Tudor ◽  
...  

Taking into consideration the current trend to mitigate the agriculture’s negative impact on the environment, this implies using new technologies and equipment for performing agricultural works. Currently, the most used equipment in agriculture is the agricultural tractor with heat engine. One alternative is represented by electric motors, usually powered by batteries. The main advantage for the environment is that zero emissions are released into the atmosphere during agricultural works. Another advantage consists of the nominal torque which could be sustained from almost zero revolutions of the electric motors resulting in lower loads on the batteries with a proper mechanical transmission. Ploughing represents the agricultural work which exploits most of the performances of an agricultural tractor, in terms of fuel consumption and engine wear. Within this paper are presented the tests performed on an electric tractor during ploughing works, at different depths and with different working speeds, in order to assess its autonomy and efficiency with a single battery charge. The electrical parameters of the tractor were recorded during tests, as well as the tractor draft force. The results were used to establish the optimal working regime of the electric tractor during ploughing works.


2021 ◽  
Vol 8 (1) ◽  
pp. H16-H20
Author(s):  
A.V.N.S. Kiran ◽  
B. Ramanjaneyulu ◽  
M. Lokanath M. ◽  
S. Nagendra ◽  
G.E. Balachander

An increase in fuel utilization to internal combustion engines, variation in gasoline price, reduction of the fossil fuels and natural resources, needs less carbon content in fuel to find an alternative fuel. This paper presents a comparative study of various gasoline blends in a single-cylinder two-stroke SI engine. The present experimental investigation with gasoline blends of butanol and propanol and magnesium partially stabilized zirconium (Mg-PSZ) as thermal barrier coating on piston crown of 100 µm. The samples of gasoline blends were blended with petrol in 1:4 ratios: 20 % of butanol and 80 % of gasoline; 20 % of propanol and 80 % of gasoline. In this work, the following engine characteristics of brake thermal efficiency (BTH), specific fuel consumption (SFC), HC, and CO emissions were measured for both coated and non-coated pistons. Experiments have shown that the thermal efficiency is increased by 2.2 % at P20. The specific fuel consumption is minimized by 2.2 % at P20. Exhaust emissions are minimized by 2.0 % of HC and 2.4 % of CO at B20. The results strongly indicate that the combination of thermal barrier coatings and gasoline blends can improve engine performance and reduce exhaust emissions.


2019 ◽  
Vol 4 (02) ◽  
pp. 113
Author(s):  
Melati Intan Kurnia ◽  
Hadi Sasana ◽  
Yustirania Septiani

<p><em>Increasing economic growth will spark against increased energy consumption. But on the other hand, increasing economic growth will also trigger the occurrence of natural damage and degradation of environmental quality derived from CO2 emissions. CO2 emissions are caused by oxidation process of fossil fuel energy. This research aims to know the causality relationship between CO2 emissions, fossil fuel consumption, electricity consumption, and economic growth in Indonesia, as well as long-term relationship between CO2 emissions, fossil fuel consumption, electricity consumption, to economic growth in Indonesia in 1990 – 2019. The used data is the secondary data that is in the form of data time series. The dependent variables of this study are economic growth, while independent variables are CO2 emissions, fossil fuel consumption, electricity consumption. The method that is used in this study is Vector Error Correction Model. The results showed that there was a one-way causality between economic growth and fossil fuel consumption, and between electricity consumption and CO2 emissions. The research also shows that on long-term CO2 emissions has a negative influence, while the consumption of fossil fuels and electricity has a positive effect on Indonesia's economic growth in 1990-2019.</em></p><p><strong><em>K</em></strong><strong><em>eywords</em></strong><em>: CO2, Energy Consumption, Economic Growth.</em></p>


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