Operating Parameters of the District Heating Substation Cooperating With the Installation of Technological Air Conditioning With High Efficiency of Heat Recovery

The article analyses the problem of determining the operating parameters of the district heating substation cooperating with the air heating system in technological air conditioning systems equipped with heat exchangers with high efficiency of heat recovery.Attention was paid to the correct selection of heat exchangers for the heat output balance depending on the heat recovery protection algorithms against a drop in the temperature of the heat transfer surface below 0℃.Critical parameters were determined in Polish climatic conditions,at which the operation of the heat recovery exchanger in the air conditioning system is switched off or limited.It has been proven that the proper functioning of the district heating substation cooperating with the installation of air conditioning with high heat recovery efficiency requires the use of two heat exchangers with different characteristics,equipped with properly selected temperature control systems.The optimal model of cooperation between the technological air conditioning system and the heating substation was also indicated.

Numerical Analysis on Ventilating and Air Conditioning Scheme of Shenyang Subway Station

Different cities have different climate conditions and outdoor temperature and humidity, so the scheme of an environment control in subway should be analyzed by considering objective conditions, project cost and operating status. In this paper, a physical and mathematical model is built according to the design of Shenyang subway (line 1), the boundary conditions of the model are defined by the design and experiments, the numerical analysis of ventilating scheme and air conditioning scheme is introduced individually, and the temperature field and air flow field of the two schemes are compared, so that the feasibility of using a ventilating scheme in subway of northeast cities is discussed. Considering comfort and economy, it can be concluded that mechanical ventilation is feasible in subway of northeast cities because the air temperature there is not very high in summer.

Practice and analysis of recycling non-drinking water from air-condition and reverse-osmosis system into rainwater collection system

This paper is based on the rainwater collection project in the retrofit of the Dongyi teaching block in Zhejiang University Xixi Campus.The analysis incorporates the local meteorological data, recycling water utilization, and precipitation adjustment.The rainwater collection system in this program also adds the condensation water from the heating, ventilation and air conditioning （ HVAC） system and the concentration from the reverse-osmosis system used for watering greens and supplying waterscapes.By calculating, the quantity of the HVAC condensation water in summer is 3.48 m3/d, and the quantity of the reverse-osmosis concentrated water is 198 to 396 L/d.This method solves the water shortage caused by high evaporation in summer and low precipitation in winter.Supported by empirical monitoring data, the proposed method significantly increases the economic efficiency of the system during the summer period.

Alternative ventilation strategies in U.S.offices:Comprehensive assessment and sensitivity analysis of energy saving potential

Mature technologies exist to reduce the heating,ventilation,and air-conditioning(HVAC) energy associated with ventilation and use ventilation proactively to save energy.This study investigated the energy use impacts in U.S.office buildings of multiple alternative ventilation strategies that combined:economizing,demand controlled ventilation(DCV),supply air temperature reset(SR),and/or a doubled ventilation rate.We used energy simulations in a Monte Carlo analysis,sampling 17 building inputs and varying locations to match the climate zone distribution of the U.S.office stock.Results indicated the possibility for significant savings compared to a baseline that ventilated constantly at a minimum rate in both a small office type with a constant air volume(CAV) HVAC system and a medium office type with a variable air volume(VAV) system.In 95%of instances,HVAC source energy savings were 5-25%in the small-CAV office(median:11%) and 6-42%in the medium-VAV office(median:27%).In the small-CAV office,DCV typically saved the most energy,usually from heating,and heating degree days and occupant density were decisive influences.In the medium-VAV office,economizing and SR were most important,DCV usually only had minor impacts,and zone temperature setpoints,along with climate indicators,were the critical influences.Other than infiltration,envelope characteristics did not strongly influence energy impacts.The untapped primary energy savings of alternative ventilation strategies over the 74%of U.S.office floorspace reasonably represented by our modeling was estimated at 36 TWh per year,with an annual value of U.S.$ 1.25 billion.

Window Air Conditioners Transition and Restriction in Saudi Arabia

This paper will provide a proposed solution for saving energy consumption due to residential air conditioners by reducing the window air conditioners type which is the most consumed energy and has a big percent of spreading inside KSA than the split type, also it will discuss some restrictions for trading and manufacturing of air conditioner devices inside KSA besides some restrictions on market and buildings to achieve the objective of reducing the consumption of energy which become a big trend in kingdom vision 2030. The results of this suggesting solution will help the decision-makers to start its plan for execution as it has a big difference between using window type from 2022 till 2030 and if we stop its sales and replace by an efficient one of split AC type in energy consumption in addition to CO2 emission reduction and decreasing of energy cost, hence our kingdom can save petroleum raw materials and keeping the environment to become clean from pollutants so that these resources are delivered to successive generations correct and clean as we received them from those before us.

Optimal Scheduling of Residential Heating, Ventilation and Air Conditioning Based on Deep Reinforcement Learning

Residential heating, ventilation and air conditioning(HVAC) provides important demand response resources for the new power system with high proportion of renewable energy. Residential HAVC scheduling strategies that adapt to realtime electricity price signals formulated by demand response program and ambient temperature can significantly reduce electricity costs while ensuring occupants' comfort. However, since the pricing process and weather conditions are affected by many factors, conventional model-based method is difficult to meet the scheduling requirements in complex environments. To solve this problem, we propose an adaptive optimal scheduling strategy for residential HVAC based on deep reinforcement learning(DRL) method. The scheduling problem can be regarded as a Markov decision process(MDP). The proposed method can adaptively learn the state transition probability to make economical decision under the tolerance violations. Specifically, the residential thermal parameters obtained by the leastsquares parameter estimation(LSPE) can provide a basis for the state transition probability of MDP. Daily simulations are verified under the electricity prices and temperature data sets, and numerous experimental results demonstrate the effectiveness of the proposed method.

地铁车站弱电设备间设备发热量确定方法

介绍了一种地铁车站弱电设备间设备发热量确定新方法,该方法利用弱电设备发热量实测数据与模型预测数据相互验证,可以有效提高弱电设备发热量确定结果的准确性。研究了室内气温、地铁是否运营、设备额定功率和车站类型等因素对设备发热量的影响。研究结果表明:基于间接测量和预测模型的地铁车站弱电设备间设备发热量确定方法可以提高和保障设备发热量计算结果的准确性;室内气温会显著影响设备外表面和围护结构内表面温度及围护结构内表面热流密度,但对设备外表面热流密度的影响较小;地铁是否运营对弱电设备间设备发热量有较大影响,地铁运营期间设备发热量大于非运营期间;设备额定功率对弱电设备间设备发热量峰值有较大影响,车站类型和建筑面积对设备发热量峰值的影响很小。

地铁站台公共区弥散送风系统结构参数研究

地铁站台公共区弥散送风系统(DASS)可以提供舒适的热环境,其结构设计参数会影响DASS送风效果。采用数值模拟方法,研究不同弥散送风板开口率、送风口数量、静压室高度以及下部空间高度等结构参数对站台公共区DASS送风效果的影响。结果表明:站台公共区气流分布均匀性和人员热舒适性随弥散送风板开口率和送风口数量的增加而增加;静压室高度在1.1m左右时的送风效果最好;下部空间高度越高,气流分布越均匀,但冷风感越强,综合初投资和系统送风效果,下部空间最优高度为3m。

基于改进的粒子群优化算法的暖通空调制冷机房BIM自动优化布置方法

采用结合Revit API和MATLAB的编程模式,对Revit平台进行了有效的二次开发,从而实现了暖通空调制冷机房设备的自动化布置设计,不仅有效地实现了设备布置方案的自动生成,还支持了布置方案的预览与验证,显著提高了设计效率和准确性。该研究的创新之处在于成功将粒子群优化算法与BIM技术相结合,为暖通空调系统的自动化设计提供了新的视角,并验证了BIM在暖通空调领域正向设计中的应用潜力。

日本HEAS-02-2022《医院设施设计指南(空调设备篇)》介绍

日本HEAS-02《医院设施设计指南(空调设备篇)》已经持续应用了30多年,对我国医院建设影响较大。历经4次修订,最新颁布的2022版是由医学主席在疫情中主持修订的,鉴于气溶胶新的传播特性提出了相应的合适措施。在医疗环境控制方面提出了许多新的思路与措施,局部修订了空气洁净度级别和各医疗科室的通风要求。依据感染管理风险评估及推荐强度与证据质量实施合理的医疗环境控制,并对一些关注点进行了澄清。

基于实测数据的地铁车站强电设备发热量影响因素分析

如果地铁车站强电设备管理用房的空调系统设计缺少可靠的设备发热量参数,不利于地铁空调系统的优化设计和节能减排。提出一种地铁车站强电设备管理用房空调设备发热量计算与分析方法,并在郑州地区4种地铁车站中进行应用,研究室内空气温度、地铁是否运营、设备额定功率和车站类型等因素对地铁强电设备管理用房设备发热量的影响。结果显示:室内气温虽然对设备外表面温度有较大影响,但是对设备外表面热流密度和设备发热量的影响较小。地铁运营期间的设备发热量大于非营运期间的设备发热量,设备发热量低于设备额定功率。

某有机化学实验室项目通风空调系统设计

有机化学实验往往会产生对人体有害的气体,有效的通风空调系统可以避免有害物泄漏,以保证实验人员在工作环境里的安全和健康。不同的有机化学实验室要求不同,其通风空调系统设计也有相应的不同要求。合成实验室通风量大,但对房间温湿度要求不高;分析仪器实验室中仪器设备较多,发热量较大,且对环境温湿度有一定的要求。本文结合某实际工程,对不同功能化学实验室通风量的确定、新风送风温度及空调设置情况和通风系统控制进行了介绍。

暖通空调给排水管道的表面改性与性能研究

为提升暖通空调铜合金排水管的表面性能,采用化学镀的方法在铜合金排水管表面制备了Ni-P/TiN镀层,研究镀液中TiN质量浓度对化学镀层物相组成、表面及截面形貌、硬度和耐磨性能的影响。结果表明,无镀层的铜合金基体主要物相为CuZn和CuZn5,表面镀层主要由非晶Ni组成;在基础镀液中适当添加TiN会形成镀层质量较好的含有胞状颗粒的镀层,而过量的TiN添加会使得镀层质量恶化。相较铜合金基体,表面镀层的硬度明显更高,且表面镀层硬度会随着镀液中TiN质量浓度的增加而增大;当TiN质量浓度为10 g/L时,表面镀层的硬度和磨损率分别为633 HV0.1和0.93×10^(-8)g/(r·N),具有相对较好的耐磨性,此时的磨损机制主要为氧化磨损。

屏蔽门漏风对地铁站台公共区弥散送风效果的影响研究

弥散送风系统(DASS)能为地铁站台公共区提供舒适的热环境,但地铁实际运行中站台存在屏蔽门漏风,对DASS送风气流的影响需要进一步研究。采用数值模拟方法,对屏蔽门漏风作用下站台公共区DASS的送风效果进行研究,并对DASS送风板开启位置进行了优化。结果表明:不考虑屏蔽门漏风作用时,一侧射流式DASS方案的站台公共区温度分布不均匀,靠近送风口一侧温度高,局部区域高于32℃;列车进站时,送风侧吊顶满布弥散送风板的方案使送风出现短路,部分气流直接从楼扶梯口排出,站台公共区靠近送风口一侧温度高于30℃,温度分布不均匀;楼扶梯附近的吊顶板封闭时,避免了气流短路现象,站台公共区温度在23~30℃范围内,送风效果得到改善;列车离站时,将楼扶梯附近的吊顶板封闭,人员活动区温度在28℃以内,满足热舒适要求。

海洋平台HVAC系统减噪技术研究

文章结合海洋平台供热通风与空气调节(HVAC)系统噪声控制的现状,重点介绍了平台HVAC系统噪声对人员和设备的影响;分析了HVAC系统噪声的来源,包括机组本身运行时产生的噪声、管线内流体流动噪声等;提出了设计和安装阶段HVAC系统噪声控制的要点,如选择低噪声设备、合理布置管线、采用隔振器和消声器等。

地下车站供冷季用能特征分析与基于需求响应的调峰潜力评估

聚焦地铁车站小时尺度用能特征,以长江中下游地区某典型屏蔽门地下车站为例,分析了车站逐时能耗构成及通风空调系统能耗的影响因素。研究结果表明,通风空调能耗为地铁车站动力照明能耗的最大占比项,占比可达83%,室外空气参数、客流量与发车密度均与通风空调能耗呈现显著相关关系。面向需求响应,建立了混合整数规划模型,评估蓄能参与下的地铁车站调峰潜力。模拟结果表明,蓄能装置参与下,车站全年累计高峰时段用电量可大幅削减,48.2%的高峰时段用电量可转移至平时段和低谷时段。

A new ventilation mode of air conditioning in subway vehicles and its air distribution performance

The traditional ventilation mode of subway vehicles adopts the form that the inlets and outlets are placed on the upper part of the cabin.The air distribution formed in this mode often cause serious problems of thermal comfort and energy consumption.In order to solve these problems caused by the traditional ventilation mode,a new hybrid ventilation mode was proposed.The hybrid ventilation mode uses both upper and underside air supply inlets.A method for evaluating the air distribution performance of subway air conditioning was developed.The method applies non-uniformity coefficients,maximum temperature difference,air diffusion performance index,modified energy utilization coefficient and Air short-circuit comprehensive coefficient.Air short-circuit comprehensive coefficient was a new index to evaluate the degree of air short-circuit of supply air.Based on the airflow simulation,the air distribution performance for the hybrid ventilation mode was evaluated using these indexes,and compared with the traditional ventilation mode.The results show that compared with the traditional ventilation mode,the hybrid ventilation mode has more uniform temperature distribution,better thermal comfort,higher energy utilization efficiency and lower degree of air short-circuit of supply air.

地铁站空调水系统节能控制研究

为了降低空调水系统的能耗,研究广州某地铁站的空调水系统节能控制策略。使用设备厂商提供的样本数据进行参数拟合,建立较为准确的设备模型,利用Trnsys软件搭建地铁站空调水系统模型。针对“大流量、小温差”现象,提出定温差控制策略,以降低水系统的能源消耗。结果显示:与定流量水系统相比,定温差控制策略下地铁站空调水系统节能率达到25.86%;在整个供冷季,相对于常规7℃的供水温度定温差控制策略,变冷冻水供水温度定温差控制策略的空调水系统节能约3.40%。

空调二次泵系统在地铁车站中的应用

杭州地铁机场轨道快线工程杭州西站为地铁四线换乘车站,地铁车站体量大、空调系统末端多、运营要求高。针对本工程特点,经过比较分析水系统采用二次泵变流量系统,根据不同区域负荷特点和运营需求进行分区划分,可有效的降低空调水系统输送能耗,为运营后的稳定运行和场所管理创造了了良好条件。同时,文中给出了二次泵系统分区划分、设备选型及运行控制方案,并对选用条件进行了验证,可为类似工程提供参考。

Characteristic studies of heat sources and performance analysis of free-cooling assisted air conditioning and ventilation systems for working faces of mineral mines

High temperature heat hazard at mineral mine becomes more and more serious as the increase of mining depth.Heat sources at working faces of mineral mines are complex and are of different characteristics,presenting new challenges for air conditioning systems.In this paper,heat sources at four types of working faces are summarized and their characteristics are investigated.Based on this,simplified equations,which are linear with length of working faces,are proposed to calculate heat dissipation rates.So that the main heat sources of different working faces can be found,and cooling load of air conditioning systems can be calculated.Then,considering main heat sources of coal mines,a typical working face is designed to investigate performances of different ventilation systems and air conditioning systems.Simulation results show that segmented ventilation systems(SC)and heat shield assisted centralized ventilation systems(CCHS)can realize much better temperature distributions at working faces.However,cooling load can be greatly reduced for CCHS,when untreated air is supplied to the coal seam side.Based on this,free cooling assisted air conditioning systems are designed,and annual average energy efficiency ratio(EERann)of the systems are investigated and compared between direct evaporate cooling and indirect evaporate cooling(IEC).For SC,as compared with scenarios without free-cooling,IEC can increase EERann by 15%-23%and 22%-32%under Benxi and Datong ambient conditions,respectively.Besides,to ensure high EERann,CCHS is preferred and it is essential to increase thermal insulation of air ducts.