پديد آورندگان :
معماريان، سينا دانشگاه هنر، استان تهران - دانشكده معماري و شهرسازي , محمدكاري، بهروز مركز تحقيقات راه، مسكن و شهرسازي استان تهران , فياض، ريما دانشگاه هنر، استان تهران - دانشكده معماري و شهرسازي , اسدي، سميه دانشگاه ايالتي پنسيلوانيا - دانشكده مهندسي معماري
كليدواژه :
دوره گذر فصلي , جرم حرارتي , مواد تغييرفازدهنده (PCM) , تهويه طبيعي , مصرف انرژي
چكيده فارسي :
محدوديت منابع سوخت هاي فسيلي و افزايش مصرف انرژي از نگراني هاي پيش روي جوامع امروزي است. از آنجا كه بخش قابل توجهي از مصرف انرژي كشور در ساختمان هاي مسكوني براي فراهم آوردن آسايش حرارتي مصرف مي شود، تاكنون تلاش زيادي براي بهبود شرايط آسايش فضاي داخل با مصرف انرژي كمتر انجام شده است. تاثير جرم حرارتي در كاهش مصرف انرژي ساختمان و افزايش آسايش حرارتي از موضوعات مورد بررسي در اين خصوص است. در اين زمينه جرم حرارتي نويني تحت عنوان مواد تغييرفازدهنده (PCM) در ساختمان سازي به ويژه سبك سازي و بلندمرتبه سازي مورد استفاده قرار مي گيرد. اين تحقيق با محدود كردن مطالعه رفتاري در بازه زماني دوره گذر فصلي بهاري و پاييزي در ساختمان هاي مسكوني در شهر تهران سعي در به حداكثر رساندن كاهش مصرف انرژي و عدم وابستگي به تاسيسات مكانيكي جهت كاهش استهلاك تاسيسات در دوره گذر فصلي دارد. در اين زمينه اثر مواد تغييرفازدهنده (PCM) با نقطه ذوب مختلف 21، 23، 25، 27، 29 درجه سلسيوس به وسيله نرم افزار انرژي پلاس (نسخه 8) شبيه سازي و تاثير آنها بر دوره گذر فصلي بهاري و پاييزي مورد بررسي قرار گرفته است. با توجه به نتايج به دست آمده ماده تغيير فازدهنده (PCM) با دماي ذوب 29 درجه سلسيوس، سبب كاهش مصرف انرژي سالانه و افزايش طول دوره گذر فصلي نسبت به كل سال با ميزان نرخ تهويه طبيعي ach 5 مي شود و در نهايت 38 روز در دوره گذر بهاري و 29 روز در دوره گذر پاييزي با مصرف انرژي صفر كيلووات ساعت روزانه منجر به عدم كاركرد سيستم هاي گرمايشي و سرمايشي مي شود.
چكيده لاتين :
Two of the main issues societies are facing with today are limited fossil fuel resources and increase in energy consumption. A significant part of energy is consumed in residential buildings to obtain thermal comfort, thus so far are, many efforts have been made to improve the indoor thermal conditions and reduce energy consumption simultaneously. One of the issues in this regard is the impact of thermal mass on energy conservation and increase of indoor thermal comfort. Seasonal transition period is a time of year when there is a change of heating to cooling and vice versa. Within this period thermal comfort may be maintained consuming no energy. Lengthening this period will help to conserve energy, and this may be achieved using indoor thermal storage. Common thermal storage materials include high density and heavy materials and sensible heat usage for energy storage. There is a new and light-weight thermal mass (phase change material) especially used in high-rise constructions to reduce the structural load and preserve thermal energy. Phase change materials (PCM) are based on latent heat energy storage. In this paper, the thermal performance of residential buildings in Tehran during seasonal transition period of spring and autumn is studied, in order to maintain the highest reduction in energy consumption without relying on mechanical equipment, and to reduce depreciation of the equipment. The impact of phase change materials (PCM), with various melting temperatures (21, 23, 25, 27 and 29oC), on the duration of seasonal transition period is studied using energy simulation. The dimensions of the studied model are similar to those of a common apartment room in the city. The model was first constructed in Ecotect software and then using EnergyPlus, and Tehran weather data, and its annual heating load was calculated. The temperature set points were 20oC for winter and 28oC for summer. Thermal performance of PCMs with various melting temperatures, regarding the best energy consumption condition during a whole year and the number of the days that were added to the seasonal transition period were identified. In hot -arid climate of Tehran natural ventilation may be used to decrease cooling load and maintain thermal comfort during transition period. To study the impacts of natural ventilation on the period, various ventilation rates, 0, 1, 3, 5, 7, and 10 ach were considered with a constant debi rate. The results revealed that using PCMs as thermal storage material and natural ventilation, energy conservation will be achieved more easily during transition period. It was found that PCM with melting point of 29oC will reduce the annual energy consumption by 15% and will increase the seasonal transition period by 20%, with 5 ach natural ventilation, and has a significant effect on reducing thermal problems of the period and performance of the mechanical equipment. The spring transition period is from 12th March to 19th May. This period for autumn is from 5th October to 5th November, which is 38 days for spring period and 29 days for fall, without any energy consumption which results in shut down of mechanical equipment.
