Introduction:
• Carnot cycle deals with heat sources of infinite heat capacity.
• The sequential cycle considers the temperature change of finite heat sources which occurs at the heat transfer process between the cycle and heat sources.
• Although a lot of researchers have studied a modified single Carnot cycle to apply it to the actual cycle more practically since Curzon and Ahlborn's research
• Ibrahim and Klein adopted sequential Carnot cycles simply as a reference one to evaluate the performance of some absorption power cycles.
• Sieniutycz and Spakovsky investigated the maximum power output of a multistage continuous endo-reversible Carnot system, they carried out the optimization study by introducing Hamiltonian function.
• Low temperature
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They obtained the numerical solutions by:
1- Hamilton-Jacobi-Bellman theory: using the dynamic programming algorithm. Baik et al. calculated theoretical maximum power of a heat engine using a low-grade heat source of about 100 by the sequential Carnot cycle model.
2- Ohman and Lundqvist: using low temperature heat sources they adopted local Carnot efficiency, which corresponds to efficiency of each Carnot cycle in sequential systems, and analyzed several power cycles with published field data.
3- Park and Kim: analyzed the thermodynamic performance of sequential Carnot cycles, established useful equations so that the performance of the sequential system is obtained and optimized, their work deal with the case of finite heat sources and infinite heat sinks.
System description and analytical modeling:
• The system is design and operation which with six variables only:
1- N : number of individual cycles in the system
2- : number of transfer unit of a heat
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• This efficiency change can be enhanced in the condition where the system works with smaller NTU, higher isentropic efficiency,
• And bigger difference between heat source initial temperature and its final temperature.
• The difference between the temperature from simulation and that from theoretical equations is explained by the result from theoretical analysis that the optimal temperature gets higher when the sequential system becomes far away from its ideal condition since an organic Rankine cycle generates more internal irreversibility than a Carnot cycle.
• The highest efficiency is the classic Carnot efficiency obtained from two initial temperatures of heat sources only and three kinds of ideal sequential efficiency are followed. Conclusions:
• It is shown that a sequential ORC has higher efficiency and increased work than a single ORC. The optimal final temperature, which is slightly higher than that from theoretical equations, is also found in the ORC simulation
• There is still a gap between this system and real
Throughout world civilization, numerous empires have dominated geographical areas with powerful military forces, effective rulers and strong economy’s. However, majority of the worlds empires have declined after centuries of dominance. The most significant similarity in all of the worlds empires is the greed of expansion. History has proven this significance to result in the falling of great empires. When empires fall, new ones are established and this is the process known as the dynastic cycle. The dynastic cycle is based off the different dynasties that once ruled China, however, the process can be used with the rise, fall and replacement of other empires. The dynastic cycle has occurred in the once dominant Ottoman empire, that dominated in Europe and the Middle East for nearly 500 years and also the Russian empire (1721-1917).
To discuss the power output, first the cycles of the engine itself needs to be mentioned.
Before I learn about Bobbie Haro’s Cycle, I didn’t know socialization is a big part of my life. For example, when my classmates think I’m Japanese because of the way I look. After learning about the cycle I realize my identity is by the people I grew up with. Second example is my parents gave me my Chinese identity and in temple I am taught to be a good individual. This illustrate an example of Harro’s socialization enforcement. Now I understand what it means and why it happens. Lastly, another example of my socialization is being a female, as a female I have limitations. I am socialized to think I have those barriers through media. For example, on television at night the girl is walking and gets kidnapped by a man. It’s scary that I always
8. If a coal-burning electrical generating plant burns 2 tons of coal to generate 6000 kWh of electricity, calculate the efficiency of the plant as the ratio of electricity output to fuel energy input (refer to Table 3.4).
Stasinopoulos, Peter, Paul Compston, Barry Newell, and Haley M. Jones. "A System Dynamics Approach in LCA to Account for Temporal Effects—a Consequential Energy LCI of Car Body-in-whites." The International Journal Of Life Cycle Assessment 17 (2012): 199-207. Springer Online Journals Complete. Web. 21 Apr. 2012. .
The next type of heat transfer is convection. Convection is heat transferred by a gas or liquid. Such as dumping hot water into a cold glass of water, making the water overall warmer. The last type of heat transfer is radiation.
Sirignano, W. A., & Liu, F. (1999). Performance increase for gas-turbine engine through combustion inside the turbine. Journal of Propulsion and Power, 15(1), 111-118.
Thermodynamics is the branch of science concerned with the nature of heat and its conversion to any form of energy. In thermodynamics, both the thermodynamic system and its environment are considered. A thermodynamic system, in general, is defined by its volume, pressure, temperature, and chemical make-up. In general, the environment will contain heat sources with unlimited heat capacity allowing it to give and receive heat without changing its temperature. Whenever the conditions change, the thermodynamic system will respond by changing its state; the temperature, volume, pressure, or chemical make-up will adjust accordingly in order to reach its original state of equilibrium. There are three laws of thermodynamics in which the changing system can follow in order to return to equilibrium.
We formulate a Performance Index J as there can be n number of optimal solutions to a problem. Once we formulate a performance Index J, we can call the solution which minimises this performance index as Optimal. This can be visualised as an energy function, as our ultimate objective is to reduce the energy consumption of the system.
In thermodynamics Refrigeration is the major application area, in which the heat is transferred from a lower temperature region to a higher temperature region. The devices which produce refrigeration are known as Refrigerators and the cycle on which it operates are called refrigeration cycles. Vapour compression refrigeration cycle is the most regularly used refrigeration cycle in which the refrigerant is alternately vaporized and condensed and in the vapor phase it is compressed. Gas refrigeration cycle is the well-known refrigeration cycle in which cycle refrigerant remains in the gaseous phase throughout the cycle. Cascade refrigeration are the other refrigeration cycles discussed in this chapter; absorption refrigeration is the one more refrigeration cycle which is used where the refrigerant is dissolved in liquid before it is compressed. One more refrigeration in which refrigeration is produced by passing the electric current through two dissimilar materials is called as the thermoelectric refrigeration.
Diesel engines are an important component of society in how they are used efficiently and effectively. Diesel engines have been around since 1892 when inventor Rudolph Diesel was able to achieve his goal of developing an internal combustion engine that can achieve maximum efficiency as seen in the Carnot Theorem. The Carnot Theorem set the standard for determining the maximum
...rmined to be environmentally friendly and are able to pay for hundreds of dollars of hydrogen fuel, then you should just buy a regular car or a hybrid vehicle that runs on gasoline. Therefore, because of the lack of readily available hydrogen fuel and the inefficient methods of producing hydrogen in a clean way, the use of fuel cell cars is highly improbable for now. However, if we are able to create apt methods of producing hydrogen without the aid of fossil fuels, we could enter an age of hydrogen within decades.
trade-offs that might be inefficient. The advantages of such high efficiency must be weighed against the risk involved.
The flow of working fluid in this type of cryocooler is oscillatory and hence have an analogy to alternative current electrical system. The working fluid inside this type of cryocooler oscillates in cycles and while passing through the regenerator exchanges heat with the wire m...
Bolton J. R., (1977), Solat Power and Fuels, New York, San Francisco, London, (by) ACADEMIC PRESS, INC