Türkiye'de Derece-Günlerin Dağılımı

Gültekin, M. Latif
Süreli Yayın başlığı
Süreli Yayın ISSN
Cilt Başlığı
Fen Bilimleri Enstitüsü
Binaların enerji korunumlu dizaynı, endüstri alanlarının seçimi, ısıtma ve soğutma amacıyla tüketilecek yakıt ve enerji miktarının hesaplanması, üretiminin planlanması ve pazarlanması, ısıtma ve klima araçlarının dizaynı, kara yollarındaki ve hava alanlarında pistlerdeki buzlanmayı önlemek veya kaldırmak amacıyla alınacak tedbirlerin tesbiti, bitkilerin çeşitli safhalarının, özellikle de hasat tarihlerinin tesbiti, tedavi ve korunma gibi değişik amaçlar için derece-gün (soğutma, ısıtma, büyüme, donma derece-günler) adlı indeksler kullanılır. Bu çalışmada DG ve hesaplaması hakkında bilgi verilmektedir. Tablo Bl.'de yer alan Türkiye'deki 255 meteoroloji istasyonundan alman günlük ortalama sıcaklıklar yardımıyla her bir istasyonun ayrı ayrı soğutma, ısıtma, büyüme, donma derece-gün değerleri hesaplanmıştır. Derece-günler -25 °C ile +35 °C arasında ki çeşitli sıcaklık seviyeleri (taban sıcaklıklar) için hesaplanmıştır. Her bir istasyon için ve -25 °C ile +35 °C arasındaki çeşitli sıcaklık seviyelerine göre hesaplanan derece- günler yardımıyla Türkiye'nin genel derece-gün (ısıtma, soğutma, büyüme ve donma derece-günler) haritaları çıkartılmıştır. Elde edilen bu sonuçlar daha önce bu konuda yapılan çeşitli çalışmaların sonuçlarıyla da karşılaştırılmıştır.
The indexes, called degree-days (heating, cooling, growing, freezing and thawing degree-days) are used for effective energy design of buildings, location of industrial areas, calculations of the amount of fuel and energy used for home and industrial heating and cooling purpose, planning of fuel and energy production and sales, design of heating and cooling machines and systems, preventing of icing on roads and run ways, calculating dates of plant phases, especially date of harvesting. Large information about degree-days and different usage of degree-days are introduced in this study. For this purpose first of all the mean temperatures of 255 meteorological station at the all different parts of Turkey obtained by averaging maximum and minimum temperatures. Then degree-days (heating, cooling, growing, freezing and thawing degree-days) are calculated for every one station by using mean daily temperatures. Degree-days are calculated for different base temperatures between -25 °C and +35 °C. At the end, general degree-day maps of Turkey are prepared for each base temperature. The results of this study is compared with the results of other studies. The mean temperature for any day indicates the amount of fuel necessary for home or industrial heating. Heating degree-days is based on the assumption that heating is not required in a building when the daily mean is 18.3 °C (65 °F) or higher. Therefore heating degree-days are determined each day by subtracting the daily mean below 18.3 °C from this temperature. Thus a day with a mean temperature of 8.3 °C has 10 heating degree days (18.3-8.3=10) and one with an average temperature of 18.3 °C or higher has none. The maintenance of a suitable indoor climate depends on the successful interpretation of atmospheric behavior both inside and outside the building. For example Daws (1970) has shown how air entering rooms mixes with, and transfers momentum to, air already present and has outlined the action of micro-convection streams above heat sources, including the human body, which loses about one-third of its heat by convection. On the other hand, the total interior heating requirement, including the length of the heating season, is normally calculated on the basis of heating degree-days or the accumulated temperatures below a select desirable base value. The base temperature, taken from standard meteorological observations, is XI often either 15.6 °C or 18.3 °C, which represent conditions 2.7 °C below the desirable comfort level, the difference being accounted for by solar radiation receipts through cooking. However, it is important to ensure that degree-day calculations are made from directly relevant local data. Thus Perry (1957) suggested that, even in a moderate-size town in an area of low relief, the combination of lower wind speeds and higher mean temperatures within the town may produce local variations of 20-30 % in annual heat requirements. Similarly, Chandler (1964) has estimated that the urban influence of London accounts for a reduction of some 400 degree-days or about 10 % of the heating values obtained at comparable heights outside the city. The amount of heat required to maintain a certain temperature in a building is proportional to the heating degree days total. This linear relationship means that doubling the heating degree days usually doubles the fuel consumption. Consequently, a fuel bill will generally be twice as high for a month with 1000 heating degree days as for a month with just 500. When seasonal totals are compared for different place, we can estimate differences in seasonal fuel consumption, however, only if we assume that building construction and living habits in these areas are the same. Heating degree day totals are a familiar part of many newspaper weather reports. Each day the previous day's accumulation is reported as well as the total thus far in the season. For the purpose of reporting heating degree days, the heating season is defined, for example as the period from July 1 through June 30. These reports often include a comparison with the total up to this date last year or with the long-term average for this date or both, and so it is a relatively simple matter to judge whether the season so far is above, below, or near normal. The amount of power required to cool a building can be estimated by using a similar index called cooling degree-days. The 18.3 °C base temperature is also used in calculating this index, cooling degree days are determined for each day by subtracting 18.3 °C from the daily mean temperature. Thus if the mean temperature for a given day is 30.3 °C, 12 cooling degree days would be accumulated. Although indices that are more sophisticated than heating and cooling degree days have been proposed to take into account the effects of wind speed, solar radiation, and humidity, degree days continue to be widely used. Growing degree-days are used in agriculture to determine the approximate dates that cops will be ready for harvesting. The number of growing degree-days for a particular crop on any day is the difference between the daily mean temperature and the base temperature of the crop-that is, the minimum temperature required for growth of that crop. The base temperature for sweet corn is 10 °C and for peas it is 4.4 °C, for example. Thus on a day when the mean temperature is 25 °C, the number of growing degree days for sweet corn is 15 and the number for peas is 20.6. Starting with the onset of the growth season, the daily growing degree day values are added; then if 1200 growing degree days are needed for that crop to mature, it should be ready to harvest when the accumulation reaches 1200. Although many factors important to plant growth, such as moisture conditions and sunlight, are not xu included in the growing degree day index, this system nevertheless serves as a simple and widely used tool in determining approximate dates of crop maturity. Freezing and thawing degree-days are used in agriculture to prevent icing in greenhouses and fields, in transporting to prevent icing.on roads and runways. Freezing and thawing degree days for any one day is the differences between the average daily temperature and 0 °C. The degree-days are minus (-) when the average daily temperature is below 0 °C. That is called freezing degree-days. The degree- days are plus (+) when the average daily temperature is above 0 °C. That is called thawing degree-days. Several factors are very important in controlling the thermal comfort of human body. Air temperature is a major factor. Other environmental conditions such as relative humidity, wind and solar radiation are also important İn comfort of human body. Because evaporation is a cooling process, the evaporation of perspiration from skiing is a natural means of regulating body temperature. When the air is very humid, however, heat loss by evaporation is reduced. As a result, a hot and humid day feels warmer and more uncomfortable than a hot and dry day. The temperature-humidity index is a well known and often used at summertime to guide human comfort or discomfort based on the conditions of temperature and humidity. Wind is another significant factor, effecting the sensation of temperature. Because wind increases the rate of evaporation and evaporation is reduced the heat. That is way a cold and windy winter day may feel much colder than the air temperature would seem to indicate. The rate of climate in the development of some industries is difficult to asses. There are examples in which climate can be shown to play a major part. The role of climate in development of some industries can be shown clearly by degree-days. The rapid growth of industry in Southern California illustrates the point for the development of the aircraft industry was initially directly related to heating degree- days so climate. Differences in observation time between climatological observing stations can result in significant errors in temperature and degree-days calculation. That is why a modified version of the Blackburn method for adjusting mean temperature data for observation time bias is presented. The modified method involves adjusting data to a "true" mean obtained by averaging all hourly temperature values for the 24 hour period ending at midnight, rather than adjusting the maximum and minimum values over the same period. The probability function of degree days below the base 18.3 °C is derived from the temperature probability function. Standard statistical analysis is applied to this function to obtain the relationship between mean degree days and mean temperature. This relationship is modified for use with available data and applied in the conversion of a monthly normal temperature for Detroit to the corresponding degree day normal Energy planning requires the information of environmental heating demand. Regional and national demand is related to both weather and population density. X1U Fuel demand information is often needed at the state level. The divisional degree-day statistics were combined into statewide weighted average degree-day statistics. Population-weighting procedure assures that each state's degree-day average is biased (weighted) towards weather conditions existing in the more populous areas of the state. Heating engineers sometimes have need for normal degree days for bases other than 18.3 °C. Future analysis of the relationship between mean temperature and mean degree days for base of 18.3 °C showed that the form of this relationship is independent of the base. This makes it possible to vary the base to any value and hence to compute degree-day normals for any base from normal temperature. Results are presented here for selected station for bases ranging from -25 °C to 35 °C. A degree-day is a unit expressing the amount of heat in terms of the persistence of a temperature for a 24-hr period of 1 °C departure from a reference temperature. As often applied snowmelt studies, the degree-day is computed by subtracting the average of the several hourly temperatures (07.00, 14.00, 21.00 local) from 0 °C. For example, if a daily mean temperature were 0 °C, there would be 0 degree-day; a daily mean of 10 °C would yield 5 degree-days. There are many ways of computing the mean temperature; the method used above is just one example. Degree-days below a reference temperature of 18.3 °C is found to be a useful indicator of a heating demand. The cumulative normals of such degree-days since September 1 during the winter months and the degree-days by months are generally published. Degree-days above 0 °C and degree-days above other reference temperatures have been used in point-snowmelt and in runoff-snowmelt computations. An accurate computation of degree-days could be made from hourly observations or from a chart recording temperatures. Air temperature thermograph records useful for such computations are relatively rare, especially for the areas on which tile winter snowpack accumulates. Computations of degree-days from the daily mean may be misleading. In many parts of the West of USA the drop of temperature to the niinimum may be so great as to yield daily means below 0 °C, indicating no degree-days, whereas snowmelt conditions may have prevailed during part of the day when air temperatures were much above the freezing point. Correlation of snowmelt with air temperature are much poorer in the forest, probably because of reradiation of heat from the forest canopy. Since heat supplied by the air is only one of the sources of heat available for snowmelt at a point, considerably superior correlation's exist when several sources of heat are taken into account. The point melting rate in inches per degree-day above 0 °C may vary from as little as 0.015 to as much as 0.20 inc./degree-day. For a spring snowmelt period, an average of 0.05 inc./degree-day may be used, but with discretion. Such point melt values for inches melt per day must be distinguished from the basin-index melt values. Endeavors to establish a workable relationship between degree-days and runoff were not very successful for short period, although such a relationship between degree- days and snowmelt was shown to be possible. XIV Site-specific total electric energy and heating oil consumption for individual residences show a very high correlation with temperature data of a climatological station when transformed to heating degree-days. The demand for fuel and power is very sensitive to changes in atmospheric conditions. One of the most clear-cut relationships is the inverse correlation which exists between space-heating requirements and air temperatures. With the marked increase in gas space-heating appliances in Britain over recent years, the peak demands for this fuel have become increasingly temperature-dependent, although for forecasting purposes. Therefore, Berrisford (1965) has rejected the degree-day method and devised an exponential weighting model, which depends on the cumulative temperature experience of the immediate past and, because it allows time for human reaction to temperature changes, is a sensitive index of day-to-day fluctuations. On the annual time scale, Manley (1957) explored the connection between coal consumption and temperature during the heating season in England and concluded that a drop of 30 per cent in the accumulated temperature deficit below normal in any one season, such as occurred several times between 1878 and 1895, would result in an additional requirement 5-6 million tones of coal. There is an important impact of climate on natural gas sales. The problem of projection monthly residential natural gas sales and evaluating interannual changes in demand is investigated by using a linear regression model adjusted monthly, with lagged monthly heating degree-days as the independent variable. Analysis of the phases of the monthly billed sales and the degree-day data indicated that monthly sales reports lag degree-days and gas consumption by 15 days on average. Lagged degree-days explain, on average, 97 % of the variability in the monthly sales reports for the study years. Annualized trends in the regression coefficients indicate changes in consumption due to conservation and changes in price. By this study, heating-cooling-growing-freezing-thawing degree-days and day numbers of Turkey (by used 255 climatological station) are calculated for different base temperatures. These values are shown in tables. Heating and freezing degree- days are shown in Table Bl, Cooling, thawing and growing degree-days are shown in Table B5. Heating and freezing day numbers are shown in Table B4, cooling, thawing and growing day numbers are shown in Table B6. Also, general degree-days and day numbers maps of Turkey are prepared. Heatmg-cooling-growing-freezing-thawing degree-days and day numbers maps are prepared by used degree-days and days numbers that showed in Table B3-B6. These maps are prepared for base temperatures between -25 °C and 35 °C and showed by Figures A1-A68. We can easily say that South East of Anatolia Region has the biggest cooling degree days by looking to maps showed by Figures A34-A68. East Anatolia Region has the smallest cooling degree days. On the other hand, we can see the biggest heating degree day and day numbers in East Anatolia Region and the smallest heating degree-days and day numbers in South East Anatolia Region. For the industry the XV region that has small heating degree-days are preferred. South East Anatolia Region is, therefore, the most suitable region of Turkey for plane industry. Freezing degree- days are high in East Anatolia Region. For this reason, it can said that icing is occur very often in this region. Freezing degree-days are small in Mediterranean See Region. Therefore, the icing is occur rarely in this region.
Tez (Yüksek Lisans) -- İstanbul Teknik Üniversitesi, Fen Bilimleri Enstitüsü, 1995
Anahtar kelimeler
derece-gün yöntemi, degree-day method