Analysis of Power Matching on Energy Savings of a Pneumatic Rotary Actuator Servo-Control System

When saving energy in a pneumatic system,the problem of energy losses is usually solved by reducing the air supply pressure.The power-matching method is applied to optimize the air-supply pressure of the pneumatic system,and the energy-saving effect is verified by experiments.First,the experimental platform of a pneumatic rotary actuator servo-control system is built,and the mechanism of the valve-controlled cylinder system is analyzed.Then,the output power characteristics and load characteristics of the system are derived,and their characteristic curves are drawn.The employed air compressor is considered as a constant-pressure source of a quantitative pump,and the power characteristic of the system is matched.The power source characteristic curve should envelope the output characteristic curve and load characteristic curve.The minimum gas supply pressure obtained by power matching represents the optimal gas supply pressure.The comparative experiments under two different gas supply pressure conditions show that the system under the optimal gas supply pressure can greatly reduce energy losses.

Comprehensive Energy-Saving Technology for RTO Flue Gas Waste Heat Utilization

In the automobile painting workshop,the oven will discharge harmful exhaust gas,the exhaust gas can be reused through the TNV system,the natural gas can meet the emission standard to the atmosphere after burning,and the high temperature gas discharged TNV the system can carry considerable heat.Utilization can effectively improve the economic benefits of the factory.At present,the more mature scheme is to heat the high temperature exhaust gas through the heat exchanger,which can reduce the steam consumption of the factory.Based on the analysis of the comprehensive energy saving content of waste heat utilization of RTO flue gas,this paper hopes to provide some reference and reference for readers.

Electricity Pricing for Natural Gas CHP Projects The Higher, the Better?

Regarding the state's policy that gives a higher on-grid electricity price to natural gas CHP (combined heat and power) projects, this paper studies the effect of it on the operation of those projects by theoretical analysis and a case study. It concludes that on-grid electricity price on the high side, compared to heat price, will lead power plants to produce more electricity but less heat, thus causing decrease of the plants' thermal eff iciency and harm to energy saving of the whole society.

Technical and Economic Aspects and Experience from 6 Years of Operating the Technology Using the Waste Heat from the Exhaust Gases of Heat Sources and 3 Years of Operating a Heating Plant in an Autonomous, Island Regime

This article is focused on technical and economic evaluation of more than 6-years experiences of operating the Waste Heat Recovery technology—the manner and system of flue gas processing generated in the combustion process in heat & power plants, cogeneration units, etc., which burn the gaseous fuel, primarily natural gas, or methane, biogas, geothermal gas, or other gaseous mixtures containing hydrogen. The solution proposes a more effective and non-traditional use of gaseous fuel for heating, the flue gases of which are processed in order to extract additional utilisable heat, with potential elimination of CO2 from them. Deploying of the heating plant in an island regime (OFF-GRID) enables definition of the benefits brought by the 3 years of operational experience and presents visions for the future offering the possibility to utilise the support energy services at the municipal as well as regional level.

Process Optimization of Coke Oven Gas to Methanol Based on the Downgrade of By-Product Steam

In the coke oven gas to methanol(CTM) process, boiling water(above 200 ℃) is generally used as the coolant in the methanol synthesis reactor, and thus, medium-pressure steam is generated as a by-product. In this paper, the influence of the coolant temperature on the CTM process is investigated from two aspects, which are the performance analyses of the reactor and the overall process and the energy integration of by-product steam. The results reveal that the coolant temperature plays a key role in the CTM process optimization. When the coolant temperature is reduced to 187 ℃, though low-pressure steam is generated, the techno-economic performance of the whole process is greatly improved: the energy/exergy efficiency is increased by 4-9%, energy cost is saved by 37.1%, income is increased by 5.4 M$/year, and the C02 emission is reduced by 21.3%.

Zero Net Energy Consuming Residential Houses

Preliminary investigation of the assigned task shows that the energy efficiency of residential houses is conditioned by the quantity of energy,consumed by all internal energy providing systems that serve for creation of comfort microclimate in all rooms of the building.The energy consuming systems of residential houses are:heating,ventilation,air conditioning,domestic hot water providing,tap water supplying systems and other life supporting facilities.If the listed systems consume possibly least quantity of energy or so cold zero net energy,the building can be qualified as energy efficient.The authors of this article try to give right answers how to provide the best,cheapest and ecologically safe solutions of assigned tasks.One of the radical solutions of the problem is the development and use of fossil fuel non-consuming installations of energy production.To overcome of mentioned problems the authors developed new type of thermal and electrical energy generating high efficiency local and central systems.For this reason,the authors of this study decided to develop new generation of heating,ventilation and domestic hot water supplying high efficiency integrated systems.

新型切割燃气丙烷与乙炔的气割分析

通过热值计算法 ,求出了使用丙烷的理论节约率。氧丙烷焰比氧乙炔焰的总热值高 ,但一次热值低 ,因此燃烧温度低 ,预热时间较长。用于低碳钢板气割时 ,气割成本随板厚不同而变化。用于厚钢板气割时节约成本显著。

Optimization and Scheduling of Byproduct Gas System in Steel Plant

A mathematical model was proposed to optimize byproduct gas system and reduce the total cost. The scope and boundaries of the system were also discussed at the same time. Boilers and gasholders were buffer users to solve the fluctuation of byproduct gases. The priority of gasholders should be ranked the last. The allocation of surplus ga- ses among gasholders and boilers was also discussed to make full use of gases and realize zero emission targets. Case study shows that the proposed model made good use of byproduct gases and at least 7.8 ~//00 operation cost was re- duced, compared with real data in iron and steel industry.

新型丙烷切割燃气的气割成本分析

采用理论推导和热值计算法 ,可求出使用丙烷气的理论节约率。氧丙烷焰比氧乙炔焰的总热值高 ,但一次热值低 ,因此燃烧温度低 ,预热时间较长。用于低碳钢板气割时 ,气割成本随板厚不同而变化。用于厚钢板气割时 。

Utilization and recycling of low-temperature waste heat of stainless steel continuous annealing furnace

Stainless steel continuous annealing furnace is mainly used for heat treatment of hot-rolled strip steel.The combustion air will be enabled to heat to 520℃by waste heat recovery system,but the discharge temperature is still up to about 300℃.Owing to with development of global emphasis on energy conservation energy saving and discharge reduction,it's significant to lower the discharge temperature to below 200℃, for the sake of achieving rational use of waste heat resource.Through the analysis of the existing heat recovery system by this study,it is proved that mixing low temperature with flue gas in high temperature standard will increase the capacity of the flue gas and deteriorate the quality of remaining heat resource.In stead of that,increasing the combustion air temperature to 600℃on the basis of stability temperature for the prerequisite of recuperator design,and giving priority to reducing fuel consumption are the better way.The recovery and recycle of low temperature gas are also be introduced.It is demonstrated by the way of setting a secondary recuperator at the exit of the primary recuperator,and using low temperature flue gas to heat the air used for drying the strip steel,the exhuast temperature of flue gas can be reduced to lower than 200℃.At the same time,the steam required for heating air is saved,the energy reserve as high as 2 300 t of standard coal per year.

Oilfield geothermal resources of the Upper Assam Petroliferous Basin,NE India

Extracting geothermal energy from the oil-producing fields is an experimental venture globally.The exploitation and utilization of geothermal energy can partly reduce the larger dependence on conventional non-renewable energy sources like oil,gas,coal,and other fossil fuels,and has a bright prospect.The Upper Assam Basin is a mature petroliferous basin of NE India,where there are several hundred low production,high water cut,or abandoned oil and gas wells that can be retrofitted as geothermal wells instead of drilling new ones.This will help bridge the gap of growing energy demand and limited supply in energy-deficient state like Assam.Situated away from the active plate boundaries and in lack of active volcanism,the Upper Assam Basin remains a low-to-medium enthalpy geothermal fluid regime.The deeper reservoir in this regard can,therefore,be the best candidate for the introspection of the potential geothermal energy reservoir reconnaissance.The selection of a deeper horizon considered in the present case has been the stratified reservoirs of the Lakadong-Therria(Lk-Th)Formation,Sylhet Group of the Lower Eocene age occurring at a variable depth of 3400 me 4600 m.The Lk-Th Formation possesses a fair-quality reservoir with lateral continuity and favourable petrophysical properties.In this study,representative gamma-ray(GR)and resistivity(R)logs were examined to work out lithology,and bed boundary demarcation,etc.The total Formation thickness varies from 97 to 157 m;the individual sand body thickness is up to 6 m.Other reservoir parameters,e.g.,porosity(φ=8-33%),water saturation(S_(w)=4.57-95.15%),geothermal gradient(2.71℃/100m to 3.92 C/100 m at 4300 m and 3608 m)respectively,and theoretical estimate of high heat flux in the range 70e100 mW/m^(2)/s,are the necessary yard-stick to measure the subsurface geothermal reserves.Efficient energy extraction will have the potential in facilitating energy utilization for industrial purposes,especially in tea processing units present nearby oilfields and also for power generation by the binary mechanism.

Multi-Period Optimal Distribution Model of Energy Medium and Its Application

A mathematical model of optimal energy medium distribution in steelmaking process is formulated. In this model, three kinds of important energy mediums including byproduct gases, steam and electricity are considered, and the objective function accounts for both the change of generation and consumption of the byproduct gases and the demand of low （or middle） pressure steam and electricity for each period to maximize the benefit of products cost and minimize the consumption of energy. The results indicate that the optimal distribution scheme of byproduct gases, middle pressure steam, low pressure steam and electricity is achieved and case study shows that 6% of operation cost is reduced by using the proposed model comparing with the previous model.

Quantification of energy related industrial eco-efficiency of China

Improving eco-efficiency is propitious for saving resources and reducing emissions,and has become a popular route to sustainable development.We define two energy-related eco-efficiencies:energy efficiency(ENE)and greenhouse gas(GHG)emission-related eco-efficiency(GEE)using energy consumption and the associated GHG emissions as the environmental impacts.Using statistical data,we analyze China’s energy consumption and GHG emissions by industrial subsystem and sector,and estimate the ENE and GEE values for China in 2007 as 4.871×10^(7)US·/PJ and 4.26×10^(8)US$/TgCO_(2)eq,respectively.Industry is the primary contributing subsystem of China’s economy,contributing 45.2%to the total economic production,using 79.6%of the energy consumed,and generating 91.4%of the total GHG emissions.We distinguish the individual contributions of the 39 industrial sectors to the national economy,overall energy consumption,and GHG emissions,and estimate their energyrelated eco-efficiencies.The results show that although ferrous metal production contributes only 3.5%to the national industrial economy,it consumes the most industrial energy(20%of total),contributes 16%to the total industrial global warming potential(GWP),and ranks third in GHG emissions.The power and heat sector ranks first in GHG emissions and contributes one-third of the total industrial GWP,although it only consumes about 8%of total industrial energy and,like ferrous metal production,contributes 3.5%to the national economy.The ENE of the ferrous metal and power and heat sectors are only 8 and 2.1×10^(7)US$/PJ,while the GEE for these two sectors are 9 and 4×10^(4)US$/GgCO_(2)eq,respectively;these are nearly the lowest ENE and GEE values among all 39 industry sectors.Finally,we discuss the possibility of ecoefficiency improvement through a comparison with other countries.