Simulation Modelling and Techno-Economics of Supercritical Carbon Dioxide Recompression Closed Brayton Cycle

In recent years, there has been global interest in meeting targets relating to energy affordability and security while taking into account greenhouse gas emissions. This has heightened major interest in potential investigations into the use of supercritical carbon dioxide (sCO2) power cycles. Climate change mitigation is the ultimate driver for this increased interest;other relevant issues include the potential for high cycle efficiency and a circular economy. In this study, a 25 MWe recompression closed Brayton cycle (RCBC) has been assessed, and sCO2 has been proposed as the working fluid for the power plant. The methodology used in this research work comprises thermodynamic and techno-economic analysis for the prospective commercialization of this sCO2 power cycle. An evaluated estimation of capital expenditure, operational expenditure, and cost of electricity has been considered in this study. The ASPEN Plus simulation results have been compared with theoretical and mathematical calculations to assess the performance of the compressors, turbine, and heat exchangers. The results thus reveal that the cycle efficiency for this prospective sCO2 recompression closed Brayton cycle increases (39% - 53.6%) as the temperature progressively increases from 550˚C to 900˚C. Data from the Aspen simulation model was used to aid the cost function calculations to estimate the total capital investment cost of the plant. Also, the techno-economic results have shown less cost for purchasing equipment due to fewer components being required for the cycle configuration as compared to the conventional steam power plant.

Conjuncture Cycles and Monetary Anomalies Are Unwelcome Guests for Sustainability

Economic cycles are not economic evils but rather healing agents for returning to equilibrium,just as inflation and deflation are not economic misfortunes but the sign of bad governance and a bitter medicine for returning to calm monetary.Unfortunately,signs of poor governance are mistaken for unfortunate events,but are instead tools offered to restore economic systems.Politics seeks consensus and does not accept the bitter cure of recession.Monetary policy is therefore called into question even if monetary anomalies also depend on errors in the management of the economy;the result is the gradual increase in interest rates.Is the idea that we can achieve the goal of complete neutrality with nature acceptable in a global economic framework pervaded by inflation and denunciation?Can we similarly argue that economic problems can coexist once the goal of neutrality has been achieved?The answer is negative.We must correct these anomalies and dysfunctions of the economy,which cannot coexist in the new context of complete and indefinite equilibrium of tomorrow.And not even the idea that conflicts can be resolved with war seems to find a place in the renewed scenario of neutrality.In this regard we can remember that,when we have reached the economic optimum of complete neutrality,or at least we are close to it,the most socially and economically advanced territories and continents will benefit from an acceleration of productivity and development.Scarcity itself will give way to the new,long-awaited reality.A condition that approaches the state of abundance and which will produce surpluses to be allocated to countries and territories that are struggling towards the condition of neutrality.The acceleration of lagging continents and the recovery of altered economic systems are therefore preconditions that can allow us to access the state of global neutrality.As we get closer to the great objective,it is to be believed that the pretense of regulating conflicts through war will also disappear.With the new reality of abundance,the economic reason for war disappears,while the aspiration of peoples-inscribed in their DNA-for solidarity and peaceful aggregation towards substantial unity becomes clear.

ECONOMIC GROWTH AND CYCLES IN MODERN CHINA

If the theory of cyclical fluctuation can be applied to modern China, the economic development ofChina in this period can be seen as consisting of several stages. At each stage as well as in the wholeperiod, chosen index system is likely to help measure the growth rate. By vertical and horizontal com-parison, this paper will try to settle the disputes on China’s modern economic development.

The Chinese Urban-rural Dual Economic Structure Model and Analysis

Based on the characteristics of urban-rural dual economic structure in China,we build a dynamic endogenous urban-rural dual economic model closely linked to China's reality,and carry out mathematical economics analysis of optimized conditions for urban and rural sectors. The main results show that:(i) The labor growth rate of urban-rural sectors must be greater than the time discount rate,or else there would be a vicious cycle of diminishing returns in the sectors;(ii) The accumulation rate of physical capital and human capital of urban-rural sectors,and the rate of technological progress,need to be greater than the corresponding depreciation rate plus the time discount rate,otherwise there would be a vicious cycle of diminishing returns in the sectors;(iii) The low accumulation rate in the rural sector,and the occurrence of labor outflow,human capital loss and lack of investment,will expand income gap between urban and rural areas,which is a reason for solidification of urban-rural dual economic structure.

Research on the Impact of Rural Labour Forces Transfer on the Urban-rural Income Based on Economics of Discrimination

On the basis of the analytical frame of discrimination, the thesis establishes a model of transfer of rural labour forces into city, and researches the impact of rural labour forces transfer on urban-rural income. The results show that the transfer of rural labour forces into city can increase urban-rural income and bridge the income gap between city and village to a certain extent. However, the capital stock of city in China is greatly more than that of the village, so the rural labour forces transfer cannot eliminate the urban-rural income gap completely. In order to elevate the rural income level in China and narrow urban-rural income gap, the government should paint a picture with two brushes at the same time: on one hand, the government should promote the transfer of rural labour forces into city, and change the status quo of dual urban-rural labour forces market structure; on the other hand, the government should increase the input in rural areas and promote the increase of rural capital stock so as to further increase rural residents' income in the process of labour forces transfer.

Research progress of socio-economic water cycle in China

China has made great progress in the study of socio-economic water cycle. She has completed national water resources appraisement and medium to long-term water supply planning. She has been engaging in study on water-deficient regions in North China and Northwest China for about half a century. For solving water shortage problem in northern China, she has put forward the famous South-to-North Water Transferring Projects, which has been set as one of the four biggest national projects in the Tenth Five-Year-Plan period although there are still debates. For promoting water use efficiency, China has been reforming her water management system, including water right system and water price system. There has already been a case of water right purchase. China has also done a lot of research on the interaction between human activity, water and ecosystem. For meeting the need of sustainability and coordinating water resources development and environmental protection, the study of ecological water requirement became very hot in recent years. There are three focuses of socio-economic water cycle study now in China: water transfer projects from the south to the north, water resources management and ecological water requirement.

Explore economic restructuring Institutional Analysis based on the urban-rural dual economic structure

China＇ s urban and rural economic and social structures are persisted, perfectly shaped, very typical. Since the new century, the Chinese government began to adjust serious distorted urban-rural relations. New rural construction, total abolition of agricultural tax, the construction of modern agriculture and other major strategic decisions have been introduced; free compulsory education in rural areas, the new rural cooperative medical care, rural public infrastructure, cultural services and other specific measures have been rolled out building. But these still can not slow down our growing urban-rural gap, China＇ s economic and social development is still running under the urban and rural pattern, and the trend has increased.

Uncertainty in life cycle economical analysis of cassava-based ethanol fuel

Biomass ethanol fuel is not only renewable but also environmental-friendly. Guangxi Zhuang Autonomous Region is developing the cassava-based ethanol fuel. Economical performance of the project is the key issue. The traditional life cycle economical analysis is just a static calculation process. Uncertainty is the character of cassava yield, cost of cassava plant, cassava price, tax rate and gasoline price, and the economical performance of the project is determined by these aspects. This study proposes an economical model of cassava-based ethanol fuel. The method of Monte Carol is used to simulate the economical performance. This method conquers the shortage of the traditional way. The results show that cassava-based ethanol fuel can get survived when the tax is exempted. Finally, the study also evaluates the potential of the economical performance.

The Analysis of Economic Growth Cycle in Henan Province

According to the data of practical GDP time sequences from 1978 to 2009 provided by Henan Statistical Yearbook of every year,Hodrick-Prescott filter model is established,and it is disintegrated into tendency component(potential yield)and fluctuation component(yield gap).The critical division loci of filter model are 4 wave crest years(1980,1988,1996 and 2007),and 3 trough years(1984,1992 and 2002).Thus since the opening up and reform,the economic growth fluctuation of Henan can be divided into 3 complete cycles and 2 incomplete cycles.Based on the economic situation and background within and without province,we preliminarily conclude the stage-characteristics of all growth cycles and the probable reasons of fluctuation.On the whole,the economic growth cycle of Henan takes on astringency to some extent,and sustainability and stability are reinforced,showing the characteristics of growth-type cycle increasingly.

Forecasting grain production costs in the backdrop of economic cycles

This research indicates that with the changes in economic cycles, China's production costs are experiencing "wave-shaped" spiral growth. From 2004 to 2008, China's grain production costs increased rapidly, with the primary driving force the rapid growth of labor, land and material costs. In the middle stage of industrialization, China's grain production costs will experience spiral growth following economic cyclical fluctuations, entering relative stability after a certain period. From 2009 to around 2012, grain production costs will drop, but average production costs may be higher than in the current upward cycle. From 2013 to around 2020, grain production costs will rise again and be much higher than in the current upward cycle.

China's economic growth and the inflation cycles since reform and opening to the outside world

This paper analyzes the cyclical characteristics of China’s economic growth and inflation since reform and opening-up, and explores the intrinsic link between the two.The study will be a guideline to keep a good balance between economic growth and inflation.

Energy, Environment, Economic Life Cycle Assessment of Cassava-based Ethanol Used as Automotive Fuel in Guangxi Province, China

A life-cycle assessment (LCA) was carried out to compare the energy, environmental and economic impacts of converting cassava to fuel ethanol in Guangxi Province, China. The entire life cycle is a system that includes stages from cassava farming to ethanol fuel combustion. A computer-based model was developed to assess energy, environmental, and economic (EEE) life cycle implication of cassava-based ethanol fuel. The LCA results for fuel ethanol were compared to conventional gasoline (CG) as a base-line case. On the life-cycle bases, the use of cassava-based ethanol fuel in Guangxi may consume more energy but reduce greenhouse gas, VOC, and CO emissions. Life cycle cost results indicate that although fuel ethanol currently is not competitive compared to conventional gasoline, it has great potentials when there are subsidies and/or yields of cassava planting are improved. In terms of balancing the energy, environmental and economical, the introduction form of cassava-based ethanol fuel would be E10. The assessment results generated from this study provide an important reference for Guangxi policy makers to better understand the trade-offs among energy, environmental effects, and economics for the most effective using of regional energy resources.

The Relationship between Corporate Real Estate and Economic Cycle

Studies on the relationship between corporate real estate(CRE)and economic cycles are very thin,especially from developing countries,such as South Africa.More,in practice,most firms hardly dedicate enough resources to CRE divisions.This leads to that management not fully maximises the wealth of shareholders.This study uses multi-linear regression to test how GDP,interest rate,and total corporate costs react to changes in CRE.The sample is made up of blue chip firms listed on the Johannesburg Stock Exchange(JSE).The results reveal mixed bag solutions-for certain firms;GDP,interest rate,and corporate costs are statistically significant and vice versa.More,this analysis can be replicated to other similar industries and indices around the world.

Net Present Value Method: A Method Recommended by ISO 15686-5 for Economic Evaluation of Building Life Cycle Costs

The publication of ISO 15686-5 is significant for studies related to the life-cycle costs of buildings. Among the many economic evaluation methods, the NPV method is recommended for use by this standard. This study explains the concept and method of PV, and then provides an explanation of the concept and method of NPV, and points out the limitations in the practical application of the method.

China＇s Economic Growth Cycles over the Past 60 Years and the Current New Cycle

This paper first summarizes China＇s economic growth rate fluctuations over the past 60 years since 1949 and examines the new developments in China＇s economic structure behind these fluctuations since reform and opening-up in the late 1970s.In tackling the global financial crisis,China is embracing a new economic cycle and must draw upon its economic history to prolong the upward momentum in the new cycle.To do so means maintaining an appropriate growth rate in the new cycle.This paper also analyzes the importance urbanization and the housing sector will play in the new cycle and how to address rising housing prices.

The Environmental Impacts and Economic Benefits on Comprehensively Promoting Alternative Fuel Buses in China: Life-Cycle and Scenario Analysis Based on LEAP Model

With the continuous development of urban public transportation, the harmful GHG emissions and pollutants generated by itself and the consequent issues such as the losses of residents’ health, economic value and residents’ welfare have become the focus of social attention. In order to study the impacts of promoting new energy vehicles on public transportation pollution mitigation and residents’ health benefits, this paper adopts the LEAP model to build some scenarios that fulfill different development needs to quantitatively analyze the ownership of new energy buses, the reduction of pollutants and the losses of residents’ health welfare. It is concluded that promoting new energy buses comprehensively can significantly reduce the emissions of atmospheric pollutants and the economic losses of residents’ health, but cannot fully realize the targets of greenhouse gas reduction under Life Cycle Analysis.

The significance of resource recycling for coking wastewater treatment:based on environmental and economic life cycle assessment

The sustainability of the coking industry is supported by reasonable production profit and environmental quality requirements.The traditional measures substantially increased the related costs for enterprises to reach standards.This paper aims to develop a comprehensive cost combined environmental impact assessment method that is necessary for the analysis of wastewater treatment systems.Typical three coking wastewater treatment processes in China were evaluated.Results showed that eutrophication dominantly contributed to the overall environmental effect.Improving effluent quality could significantly reduce the total environmental impact.In terms of an economic perspective,the price of raw materials was the main factor that affected the operating cost of comprehensive treatment.Based on subsystem analysis,the pretreatment stage accounted for the majority of environmental and cost burdens,respectively reaching 64%-78%and 64%-86%.Optimizing the pretreatment process by enhancing the efficiency of high concentration raw material recovery and substituting toxic raw materials for extractant could reduce the environmental impact and economic cost by 43.8%and 57%,respectively,which was an effective way to improve the potential performance of coking wastewater treatment plants(WWTPs).

Life cycle cost analysis of new FRP based solar parabolic trough collector hot water generation system

Parabolic trough collectors （PTCs） are employed for a variety of applications including steam generation and hot water generation. This paper deals with the experimental results and an economic analysis of a new fibre reinforced plastic （FRP） based solar PTC with an embedded electronic controlled tracking system designed and developed for hot water generation in a restaurant in Madurai, India. The new collector performance has been tested according to ASHRAE Standard 93 （1986）. The performance of a new PTC hot water generation system with a well mixed hot water storage tank is investigated by a series of extensive tests over ten months period. The average maximum storage tank water temperature observed was 74.91℃, when no energy is withdrawn from the tank to the load during the collection period. The total cost of the new economic FRP based solar PTC for hot water generation with an embedded electronic controlled tracking system is Rs. 25000 （US$ 573） only. In the present work, life cycle savings （LCS） method is employed for a detailed economic analysis of the PTC system. A computer program is used as a tool for the economic analysis. The present worth of life cycle solar savings is evaluated for the new solar PTC hot water generation system that replaces an existing electric water heating system in the restaurant and attains a value of Rs. 23171.66 after 15 years, which is a significant saving. The LCS method and the MATLAB computer simulation program presented in this paper can be used to estimate the LCS of other renewable energy systems.

Economical Evaluation of a Low-Enthalpy Geothermal Resource Located in an Arid-Zone Area

In this work an economical evaluation that established the viability of a low enthalpy geothermal resource as an energy source in north Africa is presented. The factors considered included the payback period, average rate of return, net present value, and net benefit-cost ratio. The model was based on utilising the energy source to energise four models that comprised thermal equipment consisting of water/air cooled single/half effect lithium bromide water mixture absorption chillers and an R-245fa organic Rankine cycle. These modelled cycles were based on the energy demand for Waddan city a community in southern Libya which has a demand for combined cooling/electricity only or cooling/electricity with district hot water supply. The results revealed that all of the proposed simulated stand-alone models, except the water-cooled half effect chiller, are not economically viable unless they are heavily subsidized or combined with the district hot water supply at least in the winter season.