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[技术] 帕尔瓦蒂的太阳灶

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发表于 2009-12-2 18:10:05 | 显示全部楼层 |阅读模式
为大家提供一款帕尔瓦蒂的太阳灶,非常简单也非常实用。在我国的高原地区非常适用,所以转来与大家分享。以后我还会发大量的简易太阳能炉灶,请大家关注:

First of our project is " Low Cost Solar Cooker ". For this we selected Funnel Cooker by Dr. Steven E. Jones While our experiments were being carried out we had found out that stacking of pots works better than placing them them side by side in funnel cooker. See these results here. Hence we  considered the total size of stacked cooking pots as 6 inches dia. And 6 inches height. We decided to improve this design. From the drawing we decided on a meeting point of Sunlight that are reflected  from the rim of the cone. ( Point 'x' in  figure1). The second cone of 900 was started from this level( The reference for this was taken from Prof. Mann's (1981)  improvement to VITA design ). The length of 900  cone section was taken as 6.25 inches. The base was closed and made reflective, so that any sunlight passing from sides of cooking pot is reflected back. The diagram of this with sunlight reflection is shown in Fig 2. From the diagram concentration of sunlight on cooking pot is clearly seen. This cooker is useful for unattended cooking. Reflections of sunlight with respect to position of Sun for     -60 minutes to +60 minutes is shown in fig 3. We had used pressure cooker cooking pots in stacked position with plastic cover. Opening diameter of this cooker is 24 inches. Basically this is a duel angle funnel cooker. We have Named it as 'Parvati Solar cooker'.

我们的项目首先是“低成本太阳能炊具”。为此,我们选择了医生史蒂芬琼斯漏斗试验电磁炉尽管我们正在开展,我们已经发现在这盆堆放作品并排比他们把他们一边,漏斗煲好。在这里看到这些结果。因此,我们认为,堆积炊具,总面积直径为6英寸的。和6英寸的高度。
我们决定改进这一设计。从上图我们汇合点阳光决定,是从锥环中反映出来。 (点')×'在图1。在九〇〇秒锥是开始从这样的高度(此是从曼教授的(1981)改善维设计所参考)。在900锥段长度,被认为是6.25英寸。该基地被关闭,使反射性,因此有阳光从锅里的逝世是两岸反射回来。这种与太阳光的反射图如图2。从上锅里的阳光图清楚地看到集中。这锅是有用的无人料理。阳光的思考-60分钟,就在太阳的位置来六〇分钟如图3。我们曾用塑料套叠与立场高压锅炊具。开幕这锅直径为24英寸。基本上这是决斗的角度漏斗煲。我们命名为'帕尔瓦蒂太阳灶'了。





 楼主| 发表于 2009-12-2 18:10:33 | 显示全部楼层
How to make and use Parvati Solar Cooker  
Construction of Parvati  low cost Parvati solar cooker  is given below                                          
As explained earlier Parvati Solar Cooker is Modified Funnel Cooker. This is made out of three sections. The reflector part is made out of cardboard. Stainless steel sheet also can be used as it is more durable We have constructed two types a) Circular type b) Twelve sided type Construction of circular type is given here and twelve sided version is given at Next page.
Design of Parvati Solar cooker: (Circular type)
Circular Parvati Solar cooker is made of three sections. Part C forms the upper section. Part B forms the lower section and part A forms the base of the cooker. How to cut these three parts from a single sheet of cardboard or aluminum or stainless steel sheet is shown in Fig 4 . Detailed dimensions for 24 inch diameter cooker are shown in Fig  5. This collector can collects heat energy equivalent to about 300 watts. For higher energy diameter of 30 , 36, 48 or higher can be used. For these sized collectors multiply the given dimensions by 1.25, 1.5 or 2 respectively.
Part C is semicircle shaped. Outer radius is 24 inches and inner radius is 16 inches. Join two end of this semicircle to form the upper section of cone.
Part B has outer radius of 12 inches, next circle is of radius 11.3 inches and third circle of radius 4.8 inches.  Part B is 255 degrees section of circle. Join two end of this section to form the middle section of cone. Part B has collar space to join it to Part C.
Part A is base of the structure. It is made of circle of radius 4..0 inches. There is another circle seen inside with same center. It's radius is 3.6 inches. This collar space is for joining the base to part B. The construction is shown Fig 6
Construction Tips: Small V-cuts are to be made in collar space of Part B and Part A. Then bend these V-cuts on inside. This will make it easy to join together the parts together this is shown in Fig 6. To make the structure sturdy and durable we have pasted brown paper on external surface of the cooker. After pasting the paper we have found the structure became stiff and does not need any support.


  


 楼主| 发表于 2009-12-2 18:11:00 | 显示全部楼层








Three sections are cut from the cardboard
Join two ends of part 'C' to make upper part of the cone
Join two ends of part 'B' to make lower part of the cone
Join all three parts to form the reflector
 楼主| 发表于 2009-12-2 18:11:13 | 显示全部楼层






Paste aluminum foil or other reflective surface
Completed reflector
Reflector, Cooking pots, Stands, Plastic cover
Using the PARVATI Solar Cooker:
Since Parvati solar cooker is modified version of funnel cooker it's use is identical. We have used a metallic stand to place the conical reflector. Another small tripod stand is used to place the cooking pot. As stated earlier we are using three pots in stacked position to cook the food. To retain the heat plastic cover is used. Instead of directly placing the plastic cover a small metallic stand is made and plastic bag is fitted on that. This cover is sufficiently big so that is does not  touch the cooking pots. An arrangement is made for focusing. Instead of focusing pin we have made simple arrangement. On a small metallic plate fixed to the rim of reflector a Nut bolt of 1/4 inch diameter and two inch long is fixed with two round washers at two ends. When the cooker is properly focused  shadow of upper washer coincides with the washer on the metal plate. As shown in figure while focusing it is better to adjust position in such a way that  shadow of  upper washer is slightly on the west so that sun tracking error is taken care of.




 楼主| 发表于 2009-12-2 18:11:47 | 显示全部楼层
Focusing Arrangement
While focusing, shadow of upper washer adjusted  towards west
Stacked Cooking pots








Small stand is placed at bottom of the reflector
Stacked pots are placed on the stand
Plastic Cover is put on for green house effect
Left for cooking for about 90 minutes
  Using Cooking pots in the Stacked Position
Sometimes it is necessary to cook multiple dishes. We in India generally have Rice, Curry, a Vegetable and Rotis. We have have successfully cooked  Rice, Curry and a vegetable ( Potato and Cauliflower) in this cooker. Time taken for cooking was 90 minutes. Bread pudding was also made. While cooking multiple dishes we placed Rice in lower pot, Curry in middle pot and Vegetables in upper pot. The food items that need more heat and time should be placed in the middle pot where it cooks better.
 楼主| 发表于 2009-12-2 18:21:08 | 显示全部楼层
帕尔瓦蒂太阳灶(十二单面)
太阳灶的帕尔瓦蒂建设(12单面)提供以下
这是改良双角度漏斗电磁炉在12节。这类似于反黑的Teong每小时谈设计。之间有一个这两个电饭锅设计微小的差别。 Apperture的Teong每小时谈氏锅的大小是36英寸,而Parvaticooker是24英寸和双方的长度比例。太阳能炊具双方的射线反射如图A和B,我们没有做过这两个设计的比较研究至今。
Parvati Solar Cooker (Twelve Sided)
Construction of Parvati solar cooker (Twelve sided)  is given below                                          
This is Modified Dual angled Funnel Cooker made in 12 sections. This is similar to DATS design of Teong H. Tan.There is one minor difference between design of these two cookers. Apperture size of Teong H. Tan's cooker is 36 inches while that of Parvaticooker is 24 inches and ratio of length of sides. Solar ray reflection of both the cookers is shown in Fig A and B. We have not done comparative study between these two designs so far.



Fig. A : DATS  ( Teong H. Tan)
Fig. B : Parvati Cooker.

Dimensions of single section are given in Fig.1. These dimensions are for cooker having rim diameter of 2 feet. For rim diameter of 3 feet and 4 feet multiply these dimensions by 1.5 and 2 respectively.  
     
 楼主| 发表于 2009-12-2 18:21:33 | 显示全部楼层
To simplify the construction we decided to make it out of single sheet of aluminum or cardboard instead of making multiple section and joining them together. Apart from simplifying construction this strengthened the cooker.
Take a rectangular sheet of dimension 24” * 48”. Draw a  semicircle of 24” radius. Divide this semicircle into 12 equal parts by replicating 12 times the drawing of single section. Complete drawing resembles as shown is fig 3. The drawn portion is cut along the edge. You will have the sheet now as shown in fig 2.


Next you have to bend this to form solar cooker. First bend the “A” parts of all sections to the angle  of 135 degrees with part “B”. Then bend part “B” of all sections to the angle of 165 degrees with Part “C”.
Now start bending all “C” parts on the inner side so that each “C” part makes an angle of 165 degrees with next one. After bending is complete join together two ends of  “C” parts by  using paper strip and glue. For aluminum sheet use  nut bolt and connecting strips.
All “B” parts will form the lower cone while all ”A” parts will form the part of base. A circular disc of the diameter of 7" has to be fitted to bring together all “A” parts.  For cardboard paste the ring. Then paste reflective paper or aluminum foil. For aluminum cooker aluminum disc has to be bolted. The photograph of aluminum disc bolted is shown in the photograph. This completes the construction of Cooker. The inner surface of aluminum cooker will need polishing and protective coating.


Parvati Solar cooker and Full size plans  available.
Please send in you comments and queries.
Contact or E-mail to,
Mrs. Shobha Ravindra Pardeshi, A-3/3 Saudamini Co-op Hsg. Society, Bhusari Colony, Paud Road, Kothrud, Pune India Pin 411 029.
 楼主| 发表于 2009-12-2 18:26:30 | 显示全部楼层
During visit to solarcooking.org site there is a topicrequiring attention, i.e. whether to stack the cooking pots side by side or tostack them?
While experimenting with modified funnel cooker"Parvaticooker" we found that stacking works better. Details of our experimentare given below.
Our next goal was tocook 2-3 different dishes. For this purpose we used a large stand and placedthree identical pots as above side by side, with 750 ml of water in each. Wemeasured temperature in all three pots after 90 minutes and readings were 70 0C,77 0C and 77 0C there was no improvement with differentpositioning pattern.





 楼主| 发表于 2009-12-2 18:27:11 | 显示全部楼层
Then it was decidedto work with pots stacked on each other. With available aluminum pots we wereable to stack only two pots. We decided to work with stainless steel pots thatcome with pressure cookers. In aluminum pots we placed 750 ml of water while inSS pots we placed 1 liter water in large pot and 750 ml water in smaller pot. (SS pots had diameter of 6.25 " , height of big pot is 2.75" small potis 1.75")
Temperatures recorded after 80 minutes is given in table
                  
      

   
      Aluminum            
   
      SS            
   
      Pot at top            
   
      85
0C            

   
      85 0C            
   
      Pot at Bottom            
   
      96 0C            
   
      85 0C            
   
This test clearely showed that stacking of cooking pots worksbetter than keeping them side by side in concentrator type cookers
We repeated same experiment with three SS pots stacked on eachother.
Temperatures recorded after 90 minutes is given in a tablebelow.   
  
            Top pot            
   
      500 ml of water            
   
      83 0C            
   
      Middle pot            
   
      500 ml of water            
   
      83 0C            
   
      
Bottom pot            

   
      750 ml of water            
   
      83 0C



 楼主| 发表于 2009-12-2 18:27:51 | 显示全部楼层
From this result it is evident that solarcooker with does even heating of pots in stacked position.
Some friends advised us to use aluminum cooker pots which areused in box type cookers. We again repeated the above experiment by using thesecontainers (Dimensions 6" diameter and 3" height). Temperaturesrecorded after 90 minutes are as given below.
  
      Top container
   
      750 ml of water
   
      78 0C      
   
      Bottom container
   
      750 ml of water
   
      95 0C




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