冀南农村地区冬季采暖的墙体优化设计

冀南地区农村住宅的冬季室内热环境较差,主要问题在于墙体保温能力有限,对农村住宅的墙体保温性能进行设计研究,基于实际调研的数据,构建农村住宅模型,并通过计算机仿真实验,对既有建筑墙体进行设计优化,量化不同材料结构对冀南地区农村住宅冬季采暖负荷的影响,为提高农村住宅冬季室内热环境提供数据支撑。     

集热墙式附加阳光间的冬季对流供热特性研究

将被动式太阳能建筑中的普通特朗伯集热墙系统的空气间层深度增大,形成附加阳光间。本文利用Design Builder软件的CFD模块对比分析了大空腔附加阳光间和小空腔空气间层的对流特性,并据此计算分析其冬季利用太阳能采暖供热量。结果表明:(1)附加阳光间的进深达到1.2 m可使出风口速度相对于空气间层0.1 m的集热墙提高12%,室内空间中心点温度提高约1.0℃,对流供热量提高30%以上;(2) 1.2 m进深附加阳光间情况下,集热墙大风口组合相比小风口组合对出风口速度和对流供热量影响不大,但室内空间中心点温度略有降低。     

国外冬季供暖方式一瞥

韩国崇尚地暖方便舒适又灵活 进入11月份,韩国各地普遍进入了冬季供暖期,各种供暖设施全面进入运营状态.韩国的供暖方式主要有单独供暖和集中供暖,不同种类的住宅采取不同的供暖方式,但供暖末端多采用地面辐射供暖系统. 所谓单独供暖,是指每家每户均设有取暖锅炉,自行供暖.这些家庭中的热力管道大多与城市天然气管道接通,取暖锅炉的体积相当于中国城市家庭使用的热水器的2倍或4倍.这种锅炉在室内有调控器,可以根据需要随时取暖和使用热水,温度可以调节,使用十分方便.装有这种设备的住户无所谓采暖期,只要需要随时都可取暖.由于这种方式方便实用,近年来各地高层住宅也在陆续采用单独供暖方式.     

Performance analysis of earth-pipe-air heat exchanger for winter heating

Earth-pipe-air heat exchanger (EPAHE) systems can be used to reduce the heating load of buildings in winter. A transient and implicit model based on computational fluid dynamics is developed to predict the thermal performance and heating capacity of earth-air-pipe heat exchanger systems. The model is developed inside the FLUENT simulation program. The model developed is validated against experimental investigations on an experimental set-up in Ajmer (Western India). Good agreement between simulated results and experimental data is obtained. Effects of the operating parameters (i.e. the pipe material, air velocity) on the thermal performance of earth-air-pipe heat exchanger systems are studied. The 23.42 m long EPAHE system discussed in this paper gives heating in the range of 4.1-4.8 °C for the flow velocities 2-5 m/s. Investigations on steel and PVC pipes have shown that performance of the EPAHE system is not significantly affected by the material of the buried pipe. Velocity of air through the pipe is found to greatly affect the performance of EPAHE system.     

The potential for solar space heating in Scotland

This paper investigates the relative effectiveness of passive-type solar-assisted space heating systems at various latitudes within the British Isles. A comparison is made of the useful solar gain of the same system linked to the same house at four different locations.

Month by month energy balances indicate that the annual useful solar contribution at the highest latitude (Lerwick, 60°N) is about 35% higher than at the lowest latitude (Kew, 53°N). The main reason for this difference is the higher heating loads in the North, particularly outside the winter months. The estimated available irradiation on south facing vertical surfaces was almost the same at all four locations. Previous work in the UK indicates that, contrary to the conclusions in this paper, more southerly latitudes were the most favourable for solar space heating. The reasons for the disparity are discussed. It is recommended that research and development of passive solar-assisted space heating systems should be most vigorously pursued in the more northerly latitudes of the British Isles, where both the potential benefit and the need are greatest.     

混凝土站台墙冬期施工

针对严寒地区混凝土站台墙的冬期施工，通过应用综合蓄热法热工计算公式和有关早期强度推算公式进行理论计算，合理选择了加防冻剂的综合蓄热法进行施工，达到了预期效果。     

A comparative performance study of some thermal storage materials used for solar space heating

One of the most common methods used in passive heating is the utilization of a massive wall for heat storage. Many factors affect the performance of the wall, such as the thickness and the media used for heat storage. A numerical study has been conducted on a zone heated by a thermal storage wall. Three different storage materials are examined, namely concrete, the hydrated salt CaCl₂·6H₂O and paraffin wax (N-eicosane). A numerical model is presented in this paper which judges the suitability of these materials as thermal storage mediums under the actual weather conditions of Iraq. For that purpose, the room temperature fluctuation in the zone is evaluated for each material using different thickness for each wall. The study concluded that an 8-cm-thick storage wall made from the hydrated salt is capable of maintaining the comfort temperature in the zone with the least room temperature fluctuation.     

冬期内外墙面抹灰冷作施工

结合工程实例，介绍了冬期内外墙面抹灰冷作施工方法，从冷作施工的特点、施工工艺和经济效益比较等方面做了较详细的叙述，为今后类似工程的施工，提供了可借鉴的经验。     

Field performance of an energy pile system for space heating

This paper describes the field performance of air conditioning with an energy pile system, which was applied to the pile foundations of an actual building for the purpose of reducing the cost of the underground heat exchanger. First, the building for both office and residential use, for which a space heating and cooling system using friction piles was installed, was built in Sapporo in December 2000. Second, three tests were carried out to specify the design of a heat exchanger inside the pile, and a U-tube type underground heat exchanger was adopted from the viewpoint of energy efficiency and installation costs. Long-term space heating operation measurements indicated that the seasonal average temperatures of brine returning from the underground and pile surfaces were 2.4 and 6.7 °C, respectively. The average coefficient of performance for space heating was quite high at 3.9, and the seasonal primary energy reduction rate compared with a typical air conditioning system reached 23.2%.     

Outdoor synthetic temperature for the calculation of space heating load

Methods to select the outdoor design temperature (ODT) for heating load calculation specified in current design codes in different countries are firstly discussed. Then a new method namely Stochastic Analysis is presented to determine the outdoor synthetic temperature (OST), which fully considers the randomness of weather and internal casual gains, and the thermal performance of buildings. The concept of OST enables the design of space heating system to be the trade-off between economics and risk. Finally, case studies of the influence of different building components on OST of a residential room in Beijing have been studied, which shows that OST depends upon building structures as well as weather conditions. It is recommended that OST rather than ODT should be employed in heating load calculation hence, sizing equipment for space heating systems.     

大空间厂房热风供暖系统设计

结合工程实例,介绍了以高效节能热风炉为热源的大空间厂房供暖系统设计,使用该系统可以减少初投资,节省运行费用。     

热舒适评价指标及冬季室内计算温度探讨

以Fanger热舒适方程及PMWV，PPD评价指标为理论依据，模拟计算了严寒地区居室热环境，结果表明，满足人体热舒适的室内空气温度为21－24℃，明显高于现行暖通规范规定的冬季居室内计算温度16－20℃。认为应研究适于我国严寒地区居民的热舒适标准。     

太阳能供暖系统的设计和实测

阐述了太阳能供暖系统的组成、运行原理、主要设计参数和经济效益等,并介绍了一个太阳能供暖系统的实测情况.     

某小区冬季取暖改造方案论证

以西安市某住宅小区冬季取暖方案改造为例,从业主、供热公司及社会角度分析了采用集中供暖体制给各方造成的不同程度的损失,在此基础上提出分户采暖方式,实行按用热量分户计量收费的办法,实践证明采用该方法取得良好的效益,可进一步推广应用。     

Combined space cooling and water heating system for Hong Kong residences

The combined space cooling and hot water preheating system that utilizes the rejected condenser heat is considered one of the most cost effective energy conservation measures. However, simultaneous consumption characteristics are absent in public domain. Questionnaire surveys have been conducted to obtain the relevant information from 126 households residing in high-rise public rental residential buildings in Hong Kong, achieving a confidence level of 95%. The candidate households were selected by a convenience sampling approach, and the questionnaire was constructed using either forced-choice format or in numeric response format. The data obtained were verified by correlation analysis. Data collected includes the occupancy pattern, the installed air-conditioner and water heater characteristics, and the utilization pattern of air-conditioning and hot water. Based upon the collected data and site measurements, hourly, daily and monthly heat recovery and hot water heating demand profiles were established, as well as the correlation between tap water and outdoor air temperatures. The combined profiles enable the evaluation of the feasible use of the combined system, and for future sizing of hot water storage tanks. The potential energy and fuel cost saving associated with the use of the proposed combined system for typical public rental housing in Hong Kong was estimated to be 50%.     

陶瓷太阳能集热系统在北方农村冬季采暖中的应用

结合工程实例,介绍了陶瓷太阳能采暖系统的构造及运行原理,分析了采用该系统采暖后房屋室内温度的变化情况,指出陶瓷太阳能集热系统可有效调控农村独立住宅温度,承担采暖中的大部分冷负荷。     

Exergetic cost analysis of a space heating system

In order to evaluate and improve the design of space heating systems with groundwater source heat pumps (GWHP), common design practices should be examined. In this paper, a GWHP system with common design is studied. The COP of the heat pump is 3.5 at design condition. The system is divided into five subsystems, and exergetic cost analysis is performed on it based on structural theory of thermoeconomics. The results show that the three largest relative exergy destructions and lowest exergy efficiencies occur in power generation and distribution, heat pump, and terminal unit subsystems with relative exergy destructions of 71.2%, 17.1% and 7.02% and exergy efficiencies of 32.8%, 54.8% and 65.6% respectively. The three subsystems also have the largest increases of unit exergetic costs of 2.04 W/W, 2.15 W/W, and 2.73 W/W respectively. Therefore, designers of GWHP space heating systems should pay close attention to heat pump and terminal unit subsystems, especially to the latter one because of its larger increase of unit exergetic cost. The unit exergetic cost of the system final exergetic product is 7.92 W/W. This value can be used to evaluate the system and compare it with others from the viewpoint of energy conservation.     

Optimisation of a heat pump space heating system

Because the heat pump has a very high capital cost compared with other forms of space heating, and also because the peak space heating demand in the U.K. only occurs for a few hours in the year, it has become recognised practice to install low capital cost supplementary electric heating to meet peak demands. A technique is described which optimizes the mix of heat pump and supplementary capacity to minimize the total cost of operation. A simulation model is employed which uses a weather tape containing hourly outside air temperatures to generate a space heating demand profile for a building of known thermal characteristics. The technique specifically allows the examination of intermittent heating, and in this paper is applied to a small factory operating on a variety of shift patterns. This application is of particular interest because it considers the effect of maximum demand charges on the economics of heat pump space heating systems. It is concluded that the optimum heat pump capacity depends strongly upon the length of shift, and that optimum oversizing of the heat pump system for intermittent heating appears to be lower than for conventional heating systems as a result of maximum demand pricing.     

某工程冬季施工临时采暖系统的设计与施工

介绍了某工程冬季施工临时采暖系统的设计思想及计算,对散热装置的选择、光管散热器用量的计算、采暖管道的安装以及安装和使用时注意的问题作了扼要说明,实践证明该工程取得了良好的经济和社会效益。