Closed-loop bulk air conditioning:A renewable energy-based system for deep mines in arctic regions

With depletion of shallow deposits, the number of underground mines expected to reach more than 3 km depth during their lifetime is growing. Although surface cooling plants are mostly effective in mine airconditioning, usually secondary cooling units are needed below 2 km depth. This need emerges due to the elevated thermal impacts caused by auto-compression of mine air as well as heat emissions from strata and mine machinery. As a result, in cold climates, like Canada, ultra-deep mines need their secondary underground cooling plants running year-round while the intake air must be heated to protect the sensitive machinery and liners from freezing during the winter season. To cool mine air, horizontal bulk-airconditioners with direct spray cooling systems are commonly used due to their high performance.Conventionally, sprayed water in bulk-air-coolers are mechanically circulated and refrigerated in coupled refrigeration plants. This set up can be transformed to a natural cooling/heating process by resurfacing the warm underground bulk-air-cooler spray water for mine air heating on the surface and re-sinking the chilled water for cooling in the underground bulk air coolers. This could significantly cut-down the fossil-fuel consumption in burners for mine air pre-conditioning and refrigeration cost when applicable.This paper presents an anonymous real-life example to study the feasibility of the proposed idea for an ultra-deep Canadian mine.     

Diesel generator exhaust heat recovery fully-coupled with intake air heating for off-grid mining operations: An experimental,numerical, and analytical evaluation

The customarily discarded exhaust from the fossil fuel-based power plants of the off-grid mines holds the thermal potential to fulfill the heating requirement of the underground operation. This present research fills in an important research gap by investigating the coupling effect between a diesel exhaust heat recovery and an intake air heating system employed in a remote mine. An integrative approach comprising analytical, numerical, and experimental assessment has been adapted. The novel analytical model developed here establishes the reliability of the proposed mine heating system by providing comparative analysis between a coupled and a decoupled system. The effect of working fluid variation has been examined by the numerical analysis and the possible improvement has been identified. Experimental investigations present a demonstration of the successful lab-scale implementation of the concept and validate the numerical and analytical models developed. Successful deployment of the fully coupled mine heating system proposed here will assist the mining industry on its journey towards energy-efficient, and sustainable mining practices through nearly 70% reduction in fossil fuel consumption for heating intentions.     

Electronically Controlling the System of Preheating Intake Air by Flame for Diesel Engine Cold－Start

In order to improve the cold-start performance of heavy duty diesel engine, electronically controlling the preheating of intake air by flame was researched. According to simulation and thermodynamic analysis about the partial working processes of the diesel engine, the amount of heat energy, enough to make the fuel self-ignite at the end of compression process at different temperatures of coolant and intake-air, was calculated. Several HY20 preheating plugs were used to heat up the intake air. Meanwhile, an electronic control system based on 8 bit mi-cro-controller unit (MCS-8031) was designed to automatically control the process of heating intake air. According to the various temperatures of coolant and ambient air, one plug or two plugs can automatically be selected to heat intake air. The demo experiment validated that the total system could operate successfully and achieve the sched-uled function.     

Optimized model-based control of main mine ventilation air flows with minimized energy consumption

In early 2018, the Boliden Garpenberg operation implemented an optimized control strategy as an addition to the existing ventilation on demand system. The purpose of the strategy is to further minimize energy use for main and booster fans, whilst also fulfilling airflow setpoints without violating constraints such as min/max differential pressure over fans and interaction of air between areas in mines. Using air flow measurements and a dynamical model of the ventilation system, a mine-wide coordination control of fans can be carried out. The numerical model is data driven and derived from historical operational data or step changes experiments. This makes both initial deployment and lifetime model maintenance,as the mine evolves, a comparably easy operation. The control has been proven to operate in a stable manner over long periods without having to re-calibrate the model. Results prove a 40% decrease in energy use for the fans involved and a greater controllability of air flow. Moreover, a 15% decrease of the total air flow into the mine will give additional proportional heating savings during winter periods.All in all, the multivariable controller shows a correlation between production in the mine and the ventilation system performance superior to all of its predecessors.     

可再生能源采暖系统的能耗分析

我国可再生能源资源潜力大,在未来的建筑采暖能源供应中可以形成举足轻重的地位;笔者以长春地区某建筑为依据,对太阳能采暖系统、地源热泵系统,以及常规能源系统（燃气锅炉）的热源部分进行了详细的能耗分析和比较,得出严寒地区冬季采暖选用地源热泵采暖系统节能效果显著的结论．为长春市及严寒地区利用可再生能源供暖提供可靠的节能性数据．     

用于生态工业园的冷热电联产系统

基于能的梯级利用原理,提出了一种用于生态工业园的冷热电联产系统。园区产生的生活垃圾通过厌氧消化产生沼气来发电,柴油机排放的烟气用于吸收式制冷和生活用热水,缸套水废热用于除湿。研究表明,新系统具有更优良的热力性能,化石能源的相对节能率达到34%,比原系统高14个百分点。沼气发电节省了1.5%的重油,低品位废热除湿提供了42%的冷负荷,节省了原系统中空调的电耗。能的梯级利用原理在液体除湿中的应用以及化石能源与可再生能源综合互补能够使生态工业园获得优良的节能效果。     

两种气候条件下空气热交换器的适用性分析

将新风处理到室内空气状态需要耗费大量能量,利用空气热交换器可以回收部分排风余热,降低新风能耗.空气热回收装置分为显热和全热(含显热和潜热)交换器,二者的能量回收效果取决于气候条件.我国南北气候差异很大,新风总能耗及潜热和显热能耗所占比例不同,全热交换器的节能优势只有在新风潜热能耗较高时才能充分体现.选择严寒地区的大同和夏热冬冷地区的上海两城市,分别在冬、夏季对室外空气温、湿度进行了连续31d(744h)的逐时测量.利用实测数据计算比较了两地新风能耗的差异,讨论了全热与显热交换器在上述地区的节能效果和两种热回收装置在应用时需遵守的原则,指出严寒地区最适宜的空气热回收装置为显热交换器,而夏热冬冷地区则适合选用全热交换器.     

制热模式下不同热源集中空调系统能流对比分析

在供热区域热舒适性及室内空气品质满足要求的前提条件下,通过分析从热源提取热量到最终释放到供热房间的整个环路的能流情况,分别建立了以空气源热泵热水机组和燃料燃烧的热水锅炉为热源的集中空调供热系统的整个环路的能流数学模型,并进行了对比分析.并以广州某酒店冬季供热系统为例,绘制了该系统在设计条件下,分别采用上述两种不同热源条件下完整的集中空调供热系统的能流图,直观地表现了这两种系统中各部分能流的大小和方向、能量平衡关系及能量损失以及它们之间的主要差别.识别出两种系统中主要的能流,可以为空调热源的优选及所选系统的节能降耗提供有用的信息.     

喷气式可变涡流进气系统对柴油机废气排放的影响

设计了一种喷嘴在螺旋进气道内喷射空气的可变涡流进气系统———喷气式可变涡流进气系统。研究了该系统对柴油机有害气体排放物的影响。试验结果表明,该系统在不影响进气充量系数的情况下,对柴油机有害气体排放量影响显著。其根本原因在于系统对气缸内涡流强度的改变直接影响了燃料、空气的混合和燃烧。对于涡流强度与燃烧不相匹配的发动机工况,喷气式可变涡流进气系统可以有效地降低有害气体排放量。     

效率高、环保效能好的供热制冷装置——地源热泵的开发与利用

地下浅层地能资源 (包括土壤、地下水、地表水和人类的生产生活低位能量等 )的非开采利用 ,可以通过热泵装置实现供热和制冷的双重作用。地源替代常规空气源 ,充分利用了地温逆变性 (冬暖夏凉 )和常年温变小以及蓄能的特点 ,实现了能量的再利用和良好的环保效能。使在北方冬季应用热泵供暖系统成为现实 ,并可实现供热制冷系统一体化。本文概述了国内外该领域的发展状况和该技术的可行性。     

热泵替代油田燃油加热炉技术研究

油田燃油加热炉能耗较高,排放的烟气中二氧化硫、氮氧化物及烟尘严重超标,对环境污染严重,油田原油加热炉替代工程刻不容缓。对空气源热泵、污水源热泵的工艺原理、能耗计算、设备特点及替代油田燃油加热炉工艺的可行性进行研究,并对两种热泵技术替代油田燃油加热炉后的效益进行分析。通过研究得出,空气源热泵和污水源热泵技术是进行油田加热炉燃油替代的有效途径;利用空气源热泵和污水源热泵替代燃油加热炉后可以分别降低运行费用30%和45%以上,分别降低碳排量60%和75%以上。通过加热炉燃油替代,不但可以获得可观的经济效益,还可以有效降低二氧化硫、氮氧化物及烟尘的排放。     

工艺排风热值回收的节能分析

通过对大发热量车间工艺排风问题的分析,认为在冬季将工艺排风的热量迁移至发热量小的车间,在夏季对温度较高的工艺排风进行预处理后回收利用,可取得良好的节能效果,为减少大发热量车间空调系统的需冷量和小发热量车间的补热量、改善车间工作条件、空调节能设计和改造提供技术依据。     

太阳能与地埋管热泵联合采暖实验

为了考察太阳能光热系统的蓄热能力,以及太阳能地埋管热泵联合采暖空调是否满足建筑物能量供给,针对一栋220 m2的建筑物,建立了一套太阳能地埋管热泵联合采暖空调系统.以冬季采暖负荷作为建筑物的能量需求,在此基础上配置太阳能和地埋管系统.实验结果表明:通过太阳能光热跨季节采暖蓄热,可以使土壤温度提高3℃,制热机组能力提高8%,太阳能光热和地埋管热泵系统联合采暖切实可行.     

柴油机尾气余热回收系统的能分析和火用分析

采用R245fa作为循环工质,利用有机朗肯循环回收柴油机尾气余热,从而提高柴油机的燃油经济性。对不同蒸发压力下的朗肯循环热效率和发动机不同工况下余热回收系统的火用效率以及系统各组件的火用损失率进行了计算和分析。研究结果表明,蒸发压力越高则朗肯循环效率越高,工质和尾气之间传热的不可逆损失和蒸发器出口较高的尾气温度使得蒸发器的火用损失率最大,采用余热回收系统回收发动机尾气余热,系统输出净功最高可达18.7 kW。     

200MW热电联产机组的能耗分析

一般化的供热系统由燃料能释放与转移子系统、电量发生子系统、电能输配子系统、热量发生子系统、热量输配子系统和热用户子系统构成。利用“单耗分析理论”，分析了热电联产系统的能耗构成。以 ２００ ＭＷ供热机组构成的热电联产系统为对象，定量分析了环境温度、热网供（回）水参数、供热距离和供热抽汽参数对各子系统附加单耗和热电联产系统总能耗的影响，得出了一些有益于改善热电联产节能效果的结论。     

天津城市供热现状与问题探讨

天津城市供热近十年来取得了长足发展，集中供 热发展的特点是:起步较晚，发展较快，问题较多，需求 较大.面对建设资金严重短缺、交费主体的多元化、节 能降耗摆不上日程等诸多问题，有关部门做了大量的 研究和探索，在供热管理和经营方式方面，特别是在供 热体制改革方面走在     

长春市某高校间歇采暖节能潜力分析

针对学校建筑采暖负荷特点,采用能耗分析的方法分析研究采用间歇供暖的节能性.两种运行方式耗热量对比,建筑面积为10.6 W㎡的学校建筑,采用间歇采暖运行方式可以节省能量2 913 734 kWh,相当于节约标准煤556t,并减少水泵耗电31 691 kWh,相当于节省原来用能的11.7%.由于采用间歇采暖的运行方式使用小流量供暖,不但节约了燃料消耗量,减少了污染物排放,而且也显著降低了运行费用,是一种较为理想的节能方法.     

SGCHPS土壤蓄热供热供冷效果分析

为减少建筑供热供冷能耗,实现严寒地区太阳能-土壤源热泵系统（SGCHPS）对建筑进行长期稳定的供热供冷,提出依靠季节性太阳能土壤蓄热来维持土壤热平衡、提高系统效率的方法.以严寒地区太阳能-土壤源热泵供热供冷示范工程为平台,根据建筑负荷确定系统配置,并选定4种模式交替运行,进行了3年的长期实验.实验结果表明：季节性蓄热S...     

Energy efficiency performance of multi-energy district heating and hot water supply system

A district heating and hot water supply system is presented which synthetically utilizes geothermal energy, solar thermal energy and natural gas thermal energy. The multi-energy utilization system has been set at the new campus of Tianjin Polytechnic University (TPU). A couple of deep geothermal wells which are 2 300 m in depth were dug. Deep geothermal energy cascade utilization is achieved by two stages of plate heat exchangers (PHE) and two stages of water source heat pumps (WSHP). Shallow geothermal energy is used in assistant heating by two ground coupled heat pumps (GCHPs) with 580 vertical ground wells which are 120 m in depth. Solar thermal energy collected by vacuum tube arrays (VTAs) and geothermal energy are complementarily utilized to make domestic hot water. Superfluous solar energy can be stored in shallow soil for the GCHP utilization. The system can use fossil fuel thermal energy by two natural gas boilers (NGB) to assist in heating and making hot water. The heating energy efficiency was measured in the winter of 2010-2011. The coefficients of performance (COP) under different heating conditions are discussed. The performance of hot water production is tested in a local typical winter day and the solar thermal energy utilization factor is presented. The rusults show that the average system COP is 5.75 or 4.96 under different working conditions, and the typical solar energy utilization factor is 0.324.     

进气加热对燃气轮机能效的影响研究

为了进一步提高燃气轮机及其联合循环效率,采用某452 MW级燃气-蒸汽联合机组的燃气轮机作为研究对象,在控制环境温度及燃气轮机负荷工况的基础上,研究进气加热对燃气轮机整体性能的影响。首先,利用仿真软件MATLAB对燃气轮机进行系统建模,选取燃气-蒸汽联合循环机组中余热锅炉端所产生的热量作为热源加热给水,进而通过冷热交换器对燃气轮机压气机进口空气进行预热;其次,在模型基础上对不同负荷情况下的燃气轮机进气温度以及进口导向叶片(IGV)开度进行调整。最后,通过仿真模拟得出结论:在一定负荷及环境条件下,随着进气温度的提升,燃气轮机的最佳进气温度与燃气轮机功率最大值相对应,且恰当的进气温度能够提高燃气轮机效率,降低能源消耗。