Effect of yarn hairiness on energy consumption in rotating a ring-spun yarn package

The effect of yarn hairiness on energy consumption when rotating a ring-spun yarn package is investigated theoretically and experimentally. A theoretical model is developed to calculate the energy required to rotate hair fibers, based on hair length and number as well as package speed and size. A single spindle test rig is used to verify the theoretical prediction. The experimental results confirm the theoretical prediction that the package power increases with increased yarn hairiness level and spindle speed.

Minimizing energy consumption of yarn winding in ring spinning

Ring spinning has been and will continue to be an important system for making staple yarns from different fibers in the textile industry. But high power consumption and low productivity remain the two outstanding problems with ring spinning. Based on an analysis of power distribution during yarn winding in ring spinning, models for the ratio of energy consumption to yarn production over a full yarn package are established. Spindle speed, yarn count, and package diameter are the three key parameters affecting this ratio. The effects on energy consumption of these parameters are discussed through a case study. The energy-to-production ratio increases with increased package diameter but decreases with increased spindle speed and/or yarn count (tex). The results will help guide spinners in minimizing energy consumption in ring spinning.

Recent studies on yarn tension and energy consumption in ring spinning

High energy consumption remains a key challenge for the widely used ring spinning system. Tackling this challenge requires a full understanding of the various factors that contribute to yarn tension and energy consumption during ring spinning. In this paper, we report our recent experimental and theoretical research on air drag, yarn tension and energy consumption in ring spinning. A specially constructed rig was used to simulate the ring spinning process; and yarn tension at the guide-eye was measured for different yarns under different conditions. The effect of yarn hairiness on the air drag acting on a rotating yarn package and on a ballooning yarn was examined. Models of the power requirements for overcoming the air drag, increasing the kinetic energy of the yarn package (bobbin and wound yarn) and overcoming the yarn wind-on tension were developed. The ratio of energy-consumption to yarn-production over a full yarn package was discussed. A program to simulate yarn winding in ring spinning was implemented, which can generate the balloon shape and predict yarn tension under a given spinning condition. The simulation results were verified with experimental results obtained from spinning cotton and wool yarns.

Energy consumption and real GDP in G7 countries : new evidence from panel cointegration with structural breaks

This paper examines the relationship between capital formation, energy consumption and real GDP in a panel of G7 countries using panel unit root, panel cointegration, Granger causality and long-run structural estimation. We find that capital formation, energy consumption and real GDP are cointegrated and that capital formation and energy consumption Granger cause real GDP positively in the long run. We find that a 1% increase in energy consumption increases real GDP by 0.12–0.39%, while a 1% increase in capital formation increases real GDP by 0.1–0.28%.

Urban heat island and its impact on building energy consumption

Urban areas tend to have higher air temperatures than their surroundings as a result of man-made aiterations. This phenomenon is known as the urban heat island (UHI) effect. UHI is considered to he one of the major problems encountered by the human race this century. Solar radiation that is absorbed during the day by buildings is re~emitted after sunset creating high temperatures in urban areas. Also, anthropogenic heat sources such as air conditioners and road traffic add to the rise in temperatures, A number of
studies have indicated that UHI has a significant effect on the energy use of buildings. In mid- and low-latitude cities, heat islands contribute to urban dwellers' summer discomfort and significantly higher air-conditioning loads. This chapter summarizes and reviews the latest research methodologies and findings about the effect of increased temperatures on the energy consumption of buildings. The latest developments in the heat island mitigation strategies are remarkable, However, more attention needs to be
given to the implementation and testing of these strategies in full-scale buildings.

Are shocks to energy consumption permanent or temporary? evidence from 182 countries

This article applies univariate and panel data unit root tests to annual panel data for 182 countries over the period 1979–2000 to examine the stationarity properties of per capita energy consumption. The univariate unit root test can only reject the unit root null for 56 countries or 31% of the sample at the 10% level or better. However, univariate unit root tests have low power with short spans of data and therefore failure to reject the unit root null should be treated with caution. When we apply the panel data unit root test we find overwhelming evidence that energy consumption is stationary. We discuss the policy implications of these findings and offer suggestions for future research.

A note on the long-run elasticities from the energy consumption-GDP relationship

The goal of this paper is to examine the long-run elasticities of the impacts of energy consumption on GDP and GDP on energy consumption. The energy consumption–GDP relationship is amongst the most popular relationships examined in the energy economics literature. The bulk of the extant literature has assumed a positive relationship between energy consumption and real GDP. Our analysis shows that in only around 60% of the countries considered the relationship is positive.

Reducing energy consumption of vehicle air conditioning system by an energy management system

This paper presents an energy management system to reduce the energy consumption of a vehicle when its air conditioning system is in use. The system controls the mass flow rate of the air by dynamically adjusting the blower speed and air-gates opening under various heat and loads circumstances. Simulations were conducted for a travelling vehicle operating the air conditioning system without and with the developed energy management system. The results show that the comfort temperature within the cabin room is achieved for reduced amount of energy consumption.

The energy consumption - real GDP nexus revisited : empirical evidence from 93 countries

In this paper, we analyse the long-run relationship between energy consumption and real GDP for 93 countries. We find mixed results on the impact of energy consumption on real GDP, with greater evidence at the country level supporting energy consumption having a negative causal effect on real GDP. For the G6 panel of countries, we find significant evidence that energy consumption negatively Granger causes real GDP. This means that for countries where energy consumption has a negative long-run causal effect on real GDP, energy conversation policies should not retard economic growth. We identify these countries and regional panels. We argue that these countries/regions should play a greater role in reducing carbon dioxide emissions.

Disaggregation of household energy consumption patterns in Australian

Improving energy efficiency is an important target to be achieved in residential building development and household behaviour. The aim of this research is to help building professionals and policy makers understand the current housing situations and householders’ behaviour regarding energy consumption. The results of a survey of energy consumption, including house situations and householder behaviour, of 504 households in New South Wales Australia are reported. Twelve features affecting household energy consumption are investigated. These features included cooking appliances, refrigerators, laundry appliances, televisions, computers, gaming consoles, hot water systems, space cooling and heating systems, glazing, insulation, lighting, and other major energy consumption facilities. The differences of these features across different households with different physical characteristics, social-demographic features and geographical areas are analyzed. Based on the disaggregate study, it is found that mandatory policy, geographical and socio-economic factors can significantly affect the selection of fixtures and appliances in the households. It is also found that the positive effect of the government’s mandatory policy implementation on household energy consumption behaviour is evidenced. The findings will be of use in sustainable residential building development policy-making, and tailoring the regulations and standards with consideration of the various geographical and socio-economic factors.