基于PLC的净化空调循环机组自动控制的设计与实现

净化空调控制系统由空气净化系统和自动控制系统组成。空气净化系统包括通风管道、空调机组等,其中空调机组中装有风机、过滤器、表冷器、加热器和加湿器等设备,风机的作用是使空气流动起来形成风,过滤器能够净化空气,表冷器、加热器和加湿器能够实现空气温湿度的调节。自动控制系统通过现场的各种传感器、变送器采集现场的信号,然后驱动现场的各种阀门、执行器进行动作达到调节空气的作用。其中空气净化系统的主要设备是空调机组,空调机组又有新风机组和循环机组2种,新风机组构成、工作原理及自动控制的实现在其他文献已经作了介绍,这里就循环机组相关控制参数、构成与自动控制的实现进行详细的阐述。     

Biological Status Assessment of Coral Reefs in Southern Puerto Rico: Supporting Coral Reef Protection Under the U.S. Clean Water Act

Abstract

States and other jurisdictions may protect coral reefs using biological water quality standards outlined by the United States Clean Water Act (CWA). Such protection will require long-term, regional monitoring of the resource using biological indicators and a probability-based sampling design. A 60-station survey targeting nearshore linear coral reef was conducted across southern Puerto Rico in December 2011 to document the status of reef inhabitants using a probabilistic, regional sampling design. The quantity, type and condition of stony corals, fish, gorgonians, and sponges were documented from each station, providing a robust representation of linear reef status and composition across the region. Fish represented 106 unique taxa and stony corals 32 unique taxa. Benthic organisms (stony corals, sponges, and gorgonians) averaged nearly 12 colonies per square meter, more than half of which were gorgonians. Assessment results can be used as a baseline to compare with future regional surveys to quantify change in reef condition over time (trend). Both temporal and spatial changes can be expected after large-scale disturbances like hurricanes Maria and Irma in 2017. The indicators and probabilistic sampling design support the long-term regional monitoring envisioned by the Environmental Protection Agency to implement CWA protections in Puerto Rico and elsewhere.     

Hybrid- and battery-electric vehicles offer low-cost climate benefits in China

Car ownership in China is expected to grow dramatically in the coming decades. If growing personal vehicle demand is met with conventional cars, the increase in greenhouse gas emissions will be substantial. One way to mitigate carbon dioxide (CO₂) emissions from passenger travel is to meet growing demand for cars with alternative vehicles such as hybrid- and battery-electric vehicles (HEVs and BEVs). Our study examines the cost-effectiveness of transitioning from conventional cars to HEVs and BEVs, by calculating their marginal abatement cost (MAC) of carbon in the long-run. We find that transitioning from conventional to hybrid and battery electric light-duty, four-wheel vehicles can achieve carbon emissions reductions at a negative cost (i.e. at a net benefit) in China. In 2030, the average MAC is estimated to be about −$140/ton CO₂ for HEVs and −$515/ton CO₂-saved for BEVs, varying by key parameters. The total mitigation potential of each vehicle technology is estimated to be 1.38 million tons for HEVs and 0.75 million tons for BEVs.     

清洁汽车--未来中国城市车辆发展的方向

本文着重介绍了燃气汽车近3年来在中国的发展及取得的成果,并从能源结构调整和环保两大意义上阐述了发展燃气汽车的必要性和重要性,并就未来燃气汽车的发展做了展望。     

清洁发展机制（CDM）与垃圾填埋气回收发电

根据生活垃圾填埋气体的特性、危害和相关处理技术,分析了清洁发展机制(CDM)在我国运用的前景;并介绍了邯郸市生活垃圾填埋厂运用CDM引进资金,利用垃圾填埋气体发电的情况。     

GTL柴油作为柴油机清洁代用燃料可行性分析

综述了GTL柴油的特性及其对排放的影响,并就GTL柴油和常规柴油在柴油机中的燃烧和排放特性进行了比较。同时指出GTL柴油在发动机中应用时的润滑性和对橡胶的适应性等方面存在的问题,并探讨了解决途径。     

北京西站餐饮业创建国家卫生区前后的分析

目的:调查北京西站创建国家卫生区(以下简称创卫)前后餐饮单位卫生设施、管理水平的变化,评价创卫工作效果。方法采用横断面调查的方法,对北京西站2006年、2009年餐饮单位卫生设施、量化分级水平的日常监督文书和调查问卷进行分析,对相关的因素进行比较。结果创卫前有冷荤食品加工能力的餐饮单位19个(43.2%),创卫后有34个(64.2%),χ2=23.6777,P<0.01。创卫前量化标化均值为67.627 8±5.5321,创卫后量化标化均值为80.179 6±4.481 0,t=-5.5050,P=0.000。创卫前后食品卫生知识知晓率比较,认为集体用餐配送食品不得在10～60℃储存和运输的由53.3%上升到76.6%,χ2=5.452 4,P=0.000。结论通过创卫工作,北京西站餐饮业硬件条件、卫生管理水平和从业人员食品安全知识有明显提高。     

降低涂装生产能源消耗的生产实践

为了降低涂装生产能源消耗,减少废水及废气的排放,实现清洁生产,文章介绍了对涂装生产线进行的改进,包括制纯水设备由原来的离子交换树脂设备改造为反渗透膜制水;阐述了对反渗透膜制水设备产生的浓水再利用。通过对喷漆室空调风机电机采用变频技术,对烘干室内部结构及发热元件的选用等改进,实现了降低工业水消耗30％,并降低了电能消耗,减少了制造成本。     

波浪能发电装置水叶轮设计及试验

针对一种海洋波浪能轴流式叶轮波浪能发电装置,结合我国近海波浪特点,对该装置的叶轮进行结构设计、优化选型和实验验证。该海洋波浪能轴流式叶轮波浪能发电装置以水叶轮作为唯一的波浪能转化装置,能量转化效率是影响发电的重要因素。根据浮标的运动状态,结合我国近海水纹特征,得出不同设计参数下叶轮的轴向力、扭矩、相对出口压力、能量损失系数等关键数据。这些数据为制造样机提供力学及能量转化效率方面的指导作用。     

分布式清洁供暖及氢能热电联供装置应用分析

以燃料电池为核心的热电联供是一种高效环保的分布式清洁供暖方式,越来越多国家与地区开始关注,在国内尚属新鲜事物。首先,以山东省为例,对其发展规划所提到的清洁供暖方式,了解其含义及优缺,并从成本、安全性、效果/效率、寿命、规模、应用领域六方面进行对比分析;其次,阐述分布式能源的含义、特点及分类,明确燃料电池热电联供是清洁供暖与分布式能源的良好结合体;最后,从耗煤量、耗天然气量及费用节约三个方面对燃料电池热电联供系统进行节能性分析。分析结果为今后搭建及优化系统、建模理论分析提供了一定的指导。