Energetic, economic and environmental performance of a solar-thermal-assisted HVAC system

A solar-assisted HVAC system was retrofitted in 2006-2009 onto an earlier (1980) energy-efficient building. A hybrid system of flat plate and vacuum tube solar collectors heats water in a large hot storage tank that is delivered to an absorption chiller in the cooling season or directly to heating coils in the heating season. Large chilled water storage tanks are charged off-peak and discharged during the day, cooling the building in parallel with the chiller. Measurements of the seasonal performance of the system are presented. Good overall agreement between actual measurements and earlier numerical modeling results is reported for our system, with one notable discrepancy attributable to the operation of the air terminal units, which requires tuning. In cold seasons, solar thermal energy can easily displace a large fraction of traditional heating sources. In the cooling season, the conversion of heat to cooling capacity incurs several parasitic losses, which if not accounted for properly in the design stage, have the capacity to completely offset any advantage gained from the solar system. The economics of building-scale solar thermal systems are strongly dependent on the cost of energy, and electricity in particular. The economics are favorable where electricity costs are high, and vice-versa.     

Life-cycle carbon and cost analysis of energy efficiency measures in new commercial buildings

Energy efficiency in new building construction has become a key target to lower nation-wide energy use. The goals of this paper are to estimate life-cycle energy savings, carbon emission reduction, and cost-effectiveness of energy efficiency measures in new commercial buildings using an integrated design approach, and estimate the implications from a cost on energy-based carbon emissions. A total of 576 energy simulations are run for 12 prototypical buildings in 16 cities, with 3 building designs for each building-location combination. Simulated energy consumption and building cost databases are used to determine the life-cycle cost-effectiveness and carbon emissions of each design. The results show conventional energy efficiency technologies can be used to decrease energy use in new commercial buildings by 20-30% on average and up to over 40% for some building types and locations. These reductions can often be done at negative life-cycle costs because the improved efficiencies allow the installation of smaller, cheaper HVAC equipment. These improvements not only save money and energy, but reduce a building’s carbon footprint by 16% on average. A cost on carbon emissions from energy use increases the return on energy efficiency investments because energy is more expensive, making some cost-ineffective projects economically feasible.     

燃气采暖热水炉全自动测试系统研发

介绍了燃气采暖热水炉标准的要求,论述了燃气采暖热水炉全自动测试系统的软硬件设计。     

大直径厚壁钢管等弯矩加载热弯技术试验研究

提出一种大直径厚壁钢管等弯矩加载,火焰加热弯管技术。通过对该技术受力分析及方案设计,并系统记录试验过程中存在问题和改进措施,验证该技术系统的施力系统和加热系统的可行性。该技术采用的设备成本低、构造简单、便于转场,适于直径较大的厚壁钢管的弯制,特别适于曲率较小的条件。     

燃气采暖热水炉部分负荷热效率测试方法探讨

通过国家标准并结合实际操作探讨燃气采暖热水炉部分负荷热效率的测试方法。     

加热炉余热回收系统节能防腐改造

针对催化重整和汽柴油加氢装置共3台加热炉热效率低、烟气换热管腐蚀严重等问题,进行系统的分析,并提出和落实技术改造方案,使改造后的加热炉基本达到了高效、稳定、安全运行的目的,进一步优化了生产,降低了能耗。     

相变材料地板蓄能采暖方式的应用探讨

相变材料与地板采暖系统相结合,形成一种更节能、更高效的采暖系统,该系统可充分利用夜间低价电蓄热,供次日白天的辅助热源,降低采暖系统的投资与能耗。本文主要介绍了该种系统的理论和实践研究成果。     

散热器和低温水辐射采暖系统不同连接方式及控制策略动态仿真

散热器和低温水辐射采暖系统最佳连接方式一直是业界探讨的重要课题之一。本文以动态模型为手段,模拟和分析直接、混水泵及间接连接方式系统动态响应和能耗。仿真结果表明,地板热情性的提高延长了室内温度达到稳态时间;地暖系统直接连接方式是不适宜的;混水泵和间接连接系统可节省燃料消耗约17％。从控制角度看,间接连接系统具有更好的稳定性和控制精度。     

计量供热多水泵并联管网的调试与运行

本文列举了多水泵并联供热管网运行调试用到的基本理论和计算公式,对一个住宅小区供热外网初步测试数据进行了分析,发现系统失调度过大并提出改进意见。并对改进后的系统,根据实测数据做出系统真实的管网阻力特性曲线,以及单台水泵和3台水泵并联的运行特性曲线,最后得到了水泵运行工作点。经最后调试,使系统的水力平衡和热力平衡满足了计量供热的要求。     

关于住宅采暖系统节能问题

通过对现阶段住宅采暖系统设计、运行现状以及采暖收费政策等问题的分析,探讨解决住宅采暖节能问题方法,指出应通过政府的收费体制改革调动供热企业和住户的节能积极性,使实际的供热成本趋近理论供热成本。