scholarly journals Class 1 Heating Cycles: A New Class of Thermodynamic Cycles

2021 ◽  
Author(s):  
Hong-Rui Li ◽  
Hua-Yu Li
Keyword(s):  
Thermodynamic Cycle ◽  
Medium Temperature ◽  
Power Cycles ◽  
Thermodynamic Cycles ◽  
New Class ◽  
Proper Order ◽  
Temperature Heat ◽  
Class 1 ◽  
Core Concepts ◽  
Temperature Heating

Thermodynamic cycles are not only the core concepts of thermal science, but also key approaches to energy conversion and utilization. So far, power cycles and refrigeration cycles have been the only two general classes of thermodynamic cycles. While diverse types of systems have been developed to perform thermodynamic cycles, no new general classes of thermodynamic cycles have been proposed. Based on the basic principles of thermodynamics, here we propose and analyze a new general class of thermodynamic cycles named class 1 heating cycles (HC-1s). Two basic forms of HC-1s are obtained by connecting six essential thermodynamic processes in the proper order and forming a thermodynamic cycle. HC-1s present the simplest and most general approach to utilizing the temperature difference between a high-temperature heat source and a medium-temperature heat sink to achieve efficient medium-temperature heating and/or low-temperature cooling. HC-1s fill the gaps that have existed since the origin of thermal science, and they will play significant roles in energy conservation and emission reduction.

scholarly journals Class 2 Heating Cycles: A New Class of Thermodynamic Cycles

2021 ◽  
Author(s):  
Hua-Yu Li ◽  
Hong-Rui Li
Keyword(s):  
Energy System ◽  
Medium Temperature ◽  
Power Cycles ◽  
Thermodynamic Cycles ◽  
New Class ◽  
Temperature Heat ◽  
Class 1 ◽  
Sustainable Energy System ◽  
The Relationship ◽  
Temperature Heating

Considering the significance of thermodynamic cycles in the global energy system, it is necessary to develop new general classes of thermodynamic cycles to relieve current energy and environmental problems. Inspired by the relationship between power cycles and refrigeration cycles, we realize that general classes of thermodynamic cycles should occur in pairs with opposite functions. Here we reverse class 1 heating cycles to obtain another new general class of thermodynamic cycles named class 2 heating cycles (HC-2s). HC-2s have two basic forms, and each contains six thermodynamic processes. HC-2s present the simplest and most general approach to utilizing the temperature difference between a medium-temperature heat source and a low-temperature heat sink to achieve efficient high-temperature heating. HC-2s fill the gaps that have existed since the origin of thermal science, and they will play significant roles in the global sustainable energy system.

Using Excel for the Thermodynamic Analysis of Air-Standard Cycles and Combustion Processes

2009 ◽  
Author(s):  
Amir Karimi
Keyword(s):  
Engineering Students ◽  
Solution Process ◽  
Ideal Gas ◽  
Power Cycles ◽  
Thermodynamic Cycles ◽  
Specific Heats ◽  
Property Evaluation ◽  
Difficult Time ◽  
Parametric Studies ◽  
Combustion Processes

In an undergraduate course or a course-sequence in thermodynamics mechanical engineering students are introduced to air-standard power cycles, refrigeration cycles, and the fundamentals of combustion processes. The analysis of air-standard thermodynamic cycles or solving problems involving combustion processes requires the evaluation of thermodynamic properties either from ideal gas tables or equations developed based on the assumption of constant specific heats. Many students have a difficult time to distinguish the differences between the two property evaluation methods. Also, solving problems involving power and refrigeration cycles or parametric studies of combustion processes involve several steps of property evaluation and some steps require interpolation of data listed in the thermodynamic property tables. Also solution to problems requiring trial and error iterative procedure makes the solution process tedious and time consuming, if it is done manually. This paper provides several examples to demonstrate the effectiveness of Excel in solving problems involving air-standard cycles and combustion processes.

scholarly journals Molecular Characterization of a New Class 3 Integron in Klebsiella pneumoniae

2003 ◽  
Vol 47 (9) ◽  
pp. 2838-2843 ◽  
Author(s):  
Mário Correia ◽  
Filipa Boavida ◽  
Filipa Grosso ◽  
M. J. Salgado ◽  
L. M. Lito ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Gene Cassette ◽  
Promoter Regions ◽  
Fusion Event ◽  
Integrase Gene ◽  
Gene Cassettes ◽  
New Class ◽  
Extended Spectrum ◽  
Class 1 ◽  
Cephalosporin Resistance

ABSTRACT Klebsiella pneumoniae FFUL 22K was isolated in April 1999 from the urine of an intensive care unit patient in Portugal. The strain showed an extended-spectrum cephalosporin resistance profile. A typical synergistic effect between cefotaxime or cefepime and clavulanic acid was observed. An Escherichia coli transformant displayed a similar resistance phenotype and harbored a ca. 9.4-kb plasmid (p22K9). Cloning experiments revealed that the extended-spectrum β-lactamase was encoded by bla GES-1, previously described in class 1 integrons from K. pneumoniae ORI-1 and Pseudomonas aeruginosa Pa695. Further sequence analysis demonstrated that the bla GES-1 gene cassette was located on a new class 3 integron. The integron was 2,863 bp long and consisted of an intI3 integrase gene, an attI3 recombination site, two promoter regions, and two gene cassettes. The IntI3 integrase was 98.8% identical to that of Serratia marcescens AK9373. The bla GES-1 gene cassette was inserted at the attI3 site. The second gene cassette was the result of a fusion event between bla OXA-10-type and aac(6′)-Ib gene cassettes and conferred resistance to kanamycin. This is the second class 3 integron reported and the first time that the bla GES-1 gene cassette has been found on an integron belonging to this class, highlighting the considerable heterogeneity of their genetic environment and the spread of gene cassettes among different classes of integrons.

Effect of Carbon Dioxide Recirculation and Pressure on Efficiency of the TIPS and ENEL Oxy-Coal Power Cycles

2019 ◽  
Vol 142 (6) ◽  
Author(s):  
Md. Moheiminul I. Khan ◽  
Mehrin Chowdhury ◽  
A. S. M. Arifur Rahman Chowdhury ◽  
Jad Aboud ◽  
Norman Love
Keyword(s):  
Flow Rate ◽  
Flue Gas ◽  
Thermal Efficiency ◽  
Pressure Range ◽  
Aspen Plus ◽  
Dominant Factor ◽  
Power Cycles ◽  
Thermodynamic Cycles ◽  
Coal Power ◽  
Cycle Efficiency

Abstract This paper presents the results of thermal efficiency of two coal based oxy-combustion thermodynamic cycles that are modeled using aspen plus. The objective of the present study is to perform a parametric analysis, investigating the effect of different recirculation ratios at different pressures on the efficiencies of the cycle named for the company, ENEL, and the thermo energy power system, TIPS, cycles using aspen plus® software. Variables include the flue gas recycle flow rate, the combustor temperature, and the operational pressure. Five recirculation ratios were investigated, ranging from 20% to 75%. It was determined that as the amount of recycled gas into the combustor increased, the thermal efficiency increased for both the TIPS and ENEL cycles. The highest thermal efficiency for TIPS is 37% and for ENEL is 38%, both occurring at a 75% recirculation ratio. After investigation, since combustion temperature and specific heat capacity decreases at higher recirculation ratios, the mass flow rate was the dominant factor that contributes to the increase in thermal efficiency of the cycle. At each recirculation ratio, the effect of pressure is also determined. For ENEL, the increase in cycle efficiency is 10% over the pressure range of 1–12 bar at a recirculation ratio of 20%, while the increase in cycle efficiency is only 1.5% at a higher recirculation ratio of 75%. For TIPS, the cycle efficiency increases by 4% at the recirculation ratio of 20% and increases by 3% at the recirculation ratio of 75% for a pressure range of 50–80 bar.

Comparative Performance Study of Closed Cycle Gas Turbine Utilizing Cryogenic Cold

1982 ◽  
Author(s):  
W. H. Lee
Keyword(s):  
Low Temperature ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Liquefied Natural Gas ◽  
Closed Cycle ◽  
Performance Study ◽  
Comparative Performance ◽  
Power Cycles ◽  
Temperature Heat ◽  
Cycle Temperature

The re-evaporation of Liquefied Natural Gas (LNG) is capable of acting as a low temperature heat sink for power cycles, thereby enhancing the thermal efficiency of the cycle. Leaving aside the detail of the appropriate heat exchanger technology, the comparative performance of improved high and low temperature closed cycle gas turbines is investigated using non-dimensionalized performance analysis. It was shown that the effect of lowering the minimum cycle temperature on the efficiency is equivalent to raising the maximum cycle temperature by a multiple amount. The specific output, however, decreases to a fraction of that achieved by the cycle with the original minimum cycle temperature. Implications are drawn for the application of the closed cycle gas turbine utilizing cryogenic cold.

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