Ev tipi yıkayıcı-kurutucularda ısıtma yöntemlerinin karşılaştırılması
Comparison of alternative water heating methods in household washing-drying machines
Yazar: UĞUR SARITAŞ
Danışman: PROF. DR. LÜTFULLAH KUDDUSİ
İstanbul Teknik Üniversitesi / Fen Bilimleri Enstitüsü / Makine Mühendisliği Ana Bilim Dalı / Isı-Akışkan Bilim Dalı
Derece: Yüksek Lisans, 2015
Konu: Makine Mühendisliği = Mechanical Engineering

Özet:
Yeni dünya koşullarında insanlar için zaman en ciddi parametrelerden biri haline gelmiştir, öyle ki 24 saatlik zaman dilimi insanlara yeterli gelmemektedir. Bu sebeple insanoğlu yapması gereken işlerde zamanı olabildiğince verimli kullanmaya çalışmaktadır. 
Artan nüfus ile birlikte son dönemde yaşanılan diğer bir sorun ise yerleşim problemidir. Büyük kentlerde nüfusun etkisiyle insanlar daha küçük evlerde yaşamaktadırlar ve bu durum yaşam alanlarının kısıtlanmasına yol açmaktadır. 
Bu sorunlara cevap verebilmek adına, yeni ürün gamları oluşturulmakta ve geliştirilen teknolojiler bu ürünlere uyarlanmaktadır. Bunun en güzel örneklerinden biri ev tipi yıkayıcı – kurutucu makinelerdir. Özellikle çamaşır makinelerinde yıkanan tekstillerin kurutulmasında, gerek zaman gerekse ürünlerin kapladığı yer anlamında ciddi sıkıntılar meydana gelmektedir. Yıkayıcı – kurutucu makineler içerdikleri komponentler sayesinde tekstillerin hem yıkama hem de kurutma işlemini geleneksel yöntemlere nazaran daha kısa sürede gerçekleştirmektedirler. Bunun yanında yıkama ve kurutma işlemlerinin tek makinede birleştirilmesi kullanıcılara yer tasarrufu sağlamaktadır.
Yıkayıcı – kurutucu makineler yıkama safhasında tıpkı bir çamaşır makinesi gibi su alma, ısıtma, durulama ve sıkma adımlarını gerçekleştirmektedirler. Kullanıcı dilerse ürünlerini kurutma fazına geçmeden makineden çıkarabilmektedir. Makinenin tekstilleri kurutması da istenirse kurutma adımına geçilir ve bu adımda tambur içerisindeki ve tekstillerin üzerindeki nem uzaklaştırılmaya çalışılır.
Bu tez çalışmasında amaç, yıkama ve kurutma özelliklerine sahip ev tipi makinelerde hızlı yıkama ve kurutmanın gerçekleştirilebilmesi için yıkama safhasındaki ısıtma adımında farklı ısıtma yöntemlerinin termodinamik analizlerinin yapılarak, yıkama süresinin kısaltılması açısından en uygun metoda karar verilebilmesidir. 
Tez çalışması kapsamında yıkayıcı –kurutucu makinelerin ısıtma adımında makine üzerinde bulunan komponentlerin ısıtma adımı boyunca zamana bağlı sıcaklık değişimleri ölçülmüştür. Isıtma adımında farklı ısıtma yöntemleriyle enerji bilançosu çalışmasını gerçekleştirebilmek için ölçülen sıcaklık değerlerinin yanında tahliye edilen ana yıkama suyunun miktarı ve sıcaklığı da ölçülmüştür. Ölçülen bu değerler yardımıyla verilen enerjinin komponentlerde depolanan, suya verilen ve kayıp olan miktarları hesaplanmıştır.
Çalışmada ilk olarak, ısıl çift (termokupl) yerleştirilecek komponentler ve ısıl çift sayılarına karar verilmiştir. Daha sonra makinenin sökümü gerçekleştirilerek belirlenen yerlere ısıl çiftler yerleştirildikten sonra makine yeniden yıkama yapılabilir duruma getirilmiştir. Veri Toplama Sistemi ve Agilent yazılım yardımıyla ilk olarak mevcut ısıtıcı ile yapılan çalışmaların verileri toplanmıştır. Mevcut durum analizi yapıldıktan sonra, buhar jeneratörü ve flowthrough ısıtıcı kullanılarak 40 dakikalık ısıtma adımındaki ısıtıcılar arasındaki farkların incelenme fırsatı elde edilmiştir. Çalışmalarda flowthrough ısıtıcı kullanımıyla suyun azaltılabilme olanağından dolayı ısıtmanın daha hızlı gerçekleşebileceğinin mümkün olduğu anlaşılmıştır ve çalışmanın devamında flowthrough ısıtıcılı sistemde sürenin kısaltılabileceği bir algoritma üzerine yoğunlaşılmıştır. Yeni ısıtma algoritmasının yardımıyla mevcut ısıtıcı ile ulaşılan sıcaklığa flowthrough ısıtıcı ile 5 dakika daha kısa sürede ulaşılmıştır.
Süre kısaltılmasına karar verildikten sonra çalışılan yöntem ve algoritmaların yıkama performanslarının karşılaştırılması yapılmıştır. Yıkama performansını etkileyen en önemli parametre ısıtma adımının süresi ve bu adımda ulaşılan sıcaklıktır. Bu sebepten dolayı belirlenen alternatif ısıtma yöntemlerinin yıkama performanslarının incelenmesi ve mevcut su ısıtıcısıyla yapılan yıkama performansı test sonuçlarıyla karşılaştırılması önemli bir husustur. 
Çalışmanın sonunda ise, ısıtma yöntemlerinin birbirine olan üstünlükleri belirlenmiş ve tekstillerin hızlı bir şekilde ısıtılması için mevcut ısıtma yöntemine alternatif olabilecek yönteme karar verilmiştir.

Abstract:
Time is an important parameter in the recent developing lifestyles all over the world. In fact the speed of causal live increases day by day. Therefore, the work completion time is tried to be reduced as much as possible. 
Another problem is the accommodation due to growing population. In metropolitans, people begin to live in smaller sized houses. So, this is another reason for people to have extremely limited areas to live.	
In order to find a solution to these issues, new product ranges have been recently created and new technologies are implemented to home appliance products. One of the best examples for limited area solution is new washer-dryers in household appliance market. Especially, conventional dryers due to their large dimensions and occupying large area in bathroom are a serious problem at homes. They have also an additional cost when washing machine is used.  Washing-drying machines have similar steps like a typical washing machine. These steps are; water inlet, heating up the water, rinsing, and spinning.
If users wish, they can take their clothes off the machine before the drying process, or, can continue up to the end of the drying process. At the end, machine will remove moisture either from the load of clothing and other textiles or from the tumbler alone.
The aim of this thesis is to find the best heating method and thermodynamic analysis of different kinds of heating procedures while heating step of washing phase to realize best washing and drying in household washing-drying machines.
This M. Sc. study begins with literature search. By the end of this M.Sc.study, it is planned to applicate new heating method, which is alternative to traditional resistance type water heaters. Patents and literature related to heating methods are search. Afterwards, a testing apparatus and testing algorithm is designed for the alternative heating methods.   In the light of this design, it is decided to locate thermocouples in various points to measure the temperature of these points in testing appratus. Within the scope of studies planned tests are realized for 6 kg standard weight. Thereafter, the experimental data are analysed by Microsoft Excel and MiniTab17 programmes. This phase is followed by measuring the washing performance by the colorimetric device for each heating method. In the final chapter of the study, the optimum method and heating duration are determined by introducing advantages and disadvantages of the alternative methods.
In this M. Sc. study; while heating step, changing of temperature of components on washing-drying machine versus time is measured. The amount and temperature of discharged water is measured to find out the energy balance in heating step as well. Due to these measurements, the amount of energy which converts to work, stored by components, given to the water and lost energy are calculated. In the study, at first, the number of thermocouples and components in which the thermocouples will be set is decided. Then, by taking down the machine the thermocouples are located and the machine is assembled. With the help of DAQ and Agilent VEE, the data of the studies that are conducted with the existing heater are gathered. After analysing of the present situation, by using steam generator and flowthrough heater in the heating process the differences between the heaters are analysed. In the studies, with the opportunity of decreasing the amount of water by using flowthrough heater, it is understood that the heating can be realized faster. So, in the rest of the study heating with flowthrough heater that reduces the heating time is the algorithm which is focused. Due to the new heating algorithm, the same amount of heat is supplied 5 minutes earlier by the flowthrough heater. By using the flowthrough heating system, various washing algorithms are applied and the washing performance of each algorithm is measured. The most significant parameter that affects the washing performance is the time length of heating process and the temperature reached in that step. So, the washing performances of the alternative heating methods are examined and compared to the existing water heaters. 
At the end of the study, the priorities of heating methods to each other are defined and the best one to heat the textiles fast is decided to be an alternative to the existing heating methods.
At the first step of the experimental studies the water heaters with 1950 W power is located in the machine, is used in heating step. The water amount is determined as 18 liters in the main washing cycle. The main washing water cannot be reduced below 18 liters in the current heating system. Because the whole heater in the current system should be in the water, nearly 3 liters of water must be waited under the tub for a safe operation of heater. In this situation, 3 liters of water is wasted in every washing cycle causing more water consumption and unnecesary heating of this water. This natuarally leads to loss of time and energy. 
The machine is operated in cold washing steps for 7 minutes with a 18 liters water in. Then, the heater is opened and the water heater is operated for 40 minutes. In this step, the temperature reaches up to nearly 55,7oC. The temperature values, which are recorded from the moment of closing the heater to passing before the tightening step, are used for thermodynamics analysis.
Because of the water circulation in the machine, the temperature of the load is increased by scattering. Since the weight of upper piece of balance is much more than the tub and glass the temperature is increased more slowly. Water temperature at the end of the discharge is measured. In this way, various methods can be compared. Otherwise, the measured temperatures in the alternatives heating methods will mislead in the absence of homogeneous heating. The drain water filled in the bucket causes a sudden rise in the water temperature.The measured temperatures with the current heater system are; at the laundry 56,9 0C, at the washing tub 53,7 0C, at the upper balance 27,6 0C, on the glass 44,7 0C and the water 55,7 0C.
The stored energy in the components in the experimental studies with using current heater as a result of the first law analysis is shown. According to this values, the 65,1 % of energy of heater is used for heating the water. The 11% of the given energy is stored at the tub. Leaks occurred in the system is 6%.
Similar to the current resistance water heating system, 18 liters water is used in the steam generator heating system. In steam generator heating phase, water was heated for 40 minutes. Just after the steam generator disengagement, water temperature was measured for thermodynamic investigation and this value was used for thermodynamic analysis. At the end of heating phase, temperature was measured to be 47,7 0C. Experimental system losses caused a lower water temperature than expected.

At the end of heating with steam generator, the machine parts and water were observed as the most heat absorbing components. Steam is transmitted from the generator to the inside by the aid of a nozzle. The steam blower temperature was increased more than expected, compared to heating with the existing resistance heater. When the heating phase with the steam generator was finished, the temperatures were measured to be as; laundry 44,7 0C, boiler 48,10C, blower 50,1 0C, machine door 44,9 0C, water 47,7 0C. As it is seen from these results, the temperatures were not reached to expected levels. The most important reason for this issue is the losses of the experimenta system. Moreover, the system cannot be placed into the inside of the machine.
In experiments with steam generators, 60,5% of the energy given by steam generator is used to heat the water. 10.1% is absorbed by washing tub. To heat the laundry, 7,9% is used and 6,9% of total heat was observed as system losses.
At the flowthrough heating experiment, which contains 18 litres washing water and 40 minutes heating time, the temperature of the laundry 60.7 0C, washing tub 55,5 0C, door bellow 61,2 0C, circulation pump 55,1 0C and washing water 58,9 0C are measured. The most significant point of this experiment is, the flowthrough heater is more effective than the existing resistance heating. Besides, water consumption is decreased 3 litres owing to use flowthrough heater. Moreover, a decrease in water level causes an incease in concentration of detergent. As a result, washing index increases.
At the flowthrough heating experiment, which contains 18 litres washing water and 40 minutes heating time, the water absorbed 64,1% energy of the flowthrough heater. Moreover, the 10,9% of energy was absorbed by washing tub. The energy loss of system has been calculated 5,6%.   
The temperatures are; laundry  63,8 0C, washing tub 58,6 0C, door bellow 64,4 0C and circulation pump 64,1 0C and washing water 62,9 0C under the condition 15 litres washing water and 40 minutes heating period. Similar to other experiments, energy dissipation is analysed at same condition. It is found that, 63,4% of energy was absorbed by water and 13,1% of energy was consumed by washing tub. In addition, 6,6% of energy is given to laundry. 
The water temparature is increased 7 0C more than standard heater's performance. This situation shows that heating duration can be shortened. On the other hand, this condition affect the washing performance in negative way. However, it is expected that the increase in detergent concentration will tolerate this negative effect. 
By using of flowthrough heater only 15 liters washing water is consumed. This leads to energy consumption by washing water in the amount of 60,6%. 12,6% of released energy is stored in the washing tub. Leaked energy is 4,2%. The effect of decreasing the water amount is clearly leaded to a decrease in energy consumption. In the experiment with 18 litres water, about 65% energy is given to washing water while, with 15 litres water, given energy is limited to 60,6%. Moreover, water temperature is measured higher in 15 litres experiments at the end of heating stage. The result is that the flowthrough heater reduces; the washing duration, the washing water amount and the consumed energy. 
The temperatures are; laundry 56,8 0C, washing tub 51,9 0C, door bellow 57,5 0C and machine door 48,3 0C under the condition of 15 litres washing water and 35 minutes heating period. Similar to the other experiments, energy dissipation is analysed at the same condition. It is found that, 63,4% of energy is  absorbed by water and 13,1% of energy is consumed by washing tub. In addition, 6,6% of energy is given to laundry. 
As a result of these studies, the experiments with traditional water heater which contain 18 litres water with 40 minutes heating duration the maximum water temperature is 55,7 0C. Moreover, the experiments which uses steam generator (same conditions) the maximum water temperature is 47,7 0C. In addition in heating tests with flowthrough heater under same conditions (18 litres - 40 minutes) water temperature reaches to 58,9 0C. If only the water level has reduced 3 litres the temperature reaches to 62,9 0C. At the last part of experiments, not only water level has reduced 3 litres but also, heating time has shortened 5 minutes. Under this condition the water temperature is 55,4 0C.
To compare the alternative heating methods' washing indexes,it is seen that the traditional water heater's washing index is 1,008 while steam generator's is 0,998. Washing indexes are calculated for flowthrough experiments too. In first flowthrough experiment which contains 18 litres washing water and 40 minutes of heating time, the index of washing is 1,026. While water level has been reduced 3 litres, the index is changed to 1,052. Final experiment washing index is 1,010 under 15 litres washing water and 35 minutes heating time conditions