有關(guān)太陽(yáng)能跟蹤器中英文翻譯資料0001

1、附錄1 Solar Tracker The Solar Tracker team was formed in the fall of 2005 from five stude nts in an ME desig n team, and a Smart House liaison. We continued the work of a previous solar tracker group. The task was to desig n a prototype track ing device to alig n solar pan els optimally to the sun as

2、it moves over the course of the day. The impleme ntati on of such a system dramatically in creases the efficie ncy of solar pan els used to power the Smart House. This report exam ines the process of desig ning and con struct ing the prototype, the experie nces and problems encoun tered, and suggest

3、i ons for continuing the project. 1ntroduction Solar track ing is the process of vary ing the an gle of solar pan els and collectors to take adva ntage of the full amount of the sun?s en ergy. This is done by rotat ing pan els to be perpendicular to the sun?s angle of incidenee. Initial tests in ind

4、ustry suggest that this process can in crease the efficie ncy of a solar power system by up to 50%. Give n those gain s, it is an attractive way to enhance an existi ng solar power system. The goal is to build a rig that will accomplish the solar track ing and realize the maximum in crease in effici

5、e ncy. The ultimate goal is that the project will be cost effective -that is, the gains received by in creased efficie ncy will more than offset the one time cost of developing the rig over time. In addition to the fun cti onal goals, the Smart House set forth the other followi ng goals for our proj

6、ect: it must not draw external power (self-sustaining), it must be aesthetically pleasing, and it must be weatherproof. The desig n of our solar tracker con sists of three comp onen ts: the frame, the sen sor, and the drive system. Each was carefully reviewed and tested, in stituti ng cha nges and i

7、mproveme nts along the desig n process. The frame for the tracker is an alu minum prismatic frame supplied by the previous solar tracking group. It utilizes an ,A -frame? design with the rotating axle in the middle. Attached to the bottom of this square cha nnel axle is the platform which will house

8、 the main solar collecti ng pan els. The frame itself is at an an gle to direct the pan els toward the sun (along with the in cli nati on of the roof). Its rotati on tracks the sun from east to west duri ng the day. The sen sor desig n for the system uses two small solar pan els that lie on the same

9、 pla ne as the collect ing pan els. These sen sor pan els have mirrors vertically attached betwee n them so that, uni ess the mirror faces do not receive any sun, they are shadi ng one of the pan els, while the other is recei ving full sun light.Our sen sor relies on this differe nee in light, which

10、 results in a large impeda nee differe nee across the pan els, to drive the motor in the proper direct ion un til aga in, the mirrors are not see ing any sun light, at which point both solar pan els on the sen sor receive equal sun light and no power differe nee is see n. After evaluation of the pre

11、vious direct drive system for the tracker, we designed a belt system that would be easier to maintain in the case of a failure. On one end of the frame is a motor that has the drive pulley attached to its output shaft. The motor rotates the drive belt which then rotates the pulley on the axle. This

12、system is simple and easily disassembled. It is easy to in tercha nge motors as n eeded for further testi ng and also allows for optimizatio n of the final gear ratio for resp onse of the tracker. As with any design process there were several setbacks to our progress. The first and foremost was in c

13、leme nt weather which denied us of valuable testi ng time. Despite the setbacks, we believe this design and prototype to be a very valuable proof-of-principle.During our test ing we have elimi nated many of the repetitive problems with the motor and wiri ng so that future work on the project will go

14、 more smoothly. We also have achieved our goal of track ing the sun in a ,hand&off? demo. We were able to have the tracker rotate under its own power to the an gle of the sun and stop without any assista nee. This was the main goal set forth to us by the Smart House so we believe our sensed motion p

15、rototype for solar tracking will be the foundation as they move forward in the future development and implementation of this tech no logy to the house. 2. Defining the Problem The project was to complete thedgRgV phase of the solar tracker to be used on the Smart House. While the team was comprised

16、of members from the ME160 senior design course, the customer for this project was to be the Smart House organization. Jeff Schwane, a represe ntative from the Smart House, was our liais on and com muni cated to our group the direct ion Smart House leadership wished us to proceed. At our first meet i

17、ng with Jeff and Tom Rose, the followi ng n eeds were ide ntified: 1. Track the sun duri ng the day 2. Use no exter nal power source 3. Weather proof 4. Cost effective power gai n 5. Must look good 6. Solar panel versatile i.e. can fit differe nt types of pan els With these needs in hand, we constru

18、cted a Quality Function Deployment chart. This chart can be found in Appe ndix A.The QFD showed the major areas of concern might have bee n: nu mber of pan els/size of pan els, internal power requireme nts, motor torque required. At our first meeting we were also able to set up our goals for the sem

19、ester. Having a working prototype capable of tracking the sun was to be the main goal for the end of the semester, but we soon found that in order to accomplish this, we would be forced to omit porti ons of the desig n criteria in hopes they would be worked out later. This would result in the optimi

20、zation of platform space on the roof to be irrelevant, with our goal being to have one platform track. It also led to the assumption that our base would not need to be tested for stability or required to be faste ned to the roof. With an idea of where we were to begi n, from scratch with the possibi

21、lity of using the frame from the“ REV T design, and an idea o were to fin ish, with a movi ng prototype, we con structed the Gantt chart that can be found in Appe ndix B. Our group pla nned to meet with Jeff once a week to make sure we were on track with the needs of the Smart House. Jeff would also

22、 meet with Tom Rose, the director of Smart House, at least once a week in order to keep every one on the same page. With our goals in mind we embarked on the process of idea gen erati on. 3. Concepts and Research 3.1 Tracking Type Our group used a brain storm ing approach to con cept gen erati on. W

23、e thought of ideas for different solar tracking devices, which proved difficult at times due to the existing frame and con cept prese ntedto us by Smart House. Other con cepts were gen erated through research of pre-existing solar tracking devices. Originally our concept generation was geared toward

24、s creat ing a completely new solar tracker outside of the con strai nts of the previous structure give n to us by Smart House. This in itial brain storm ing gen erated many con cepts. The first one was a un i-axial track ing system that would track the sun east to west across the sky duri ng the cou

25、rse of a day and retur n at the end of the day. This con cept prese nted the adva ntage of simplicity and presented us with the option to use materials from the previous structure (which was also inten ded to be a un i-axial tracker) in con struct ion. Ano ther more complex con cept was to track the

26、 sun bi-axially which would invo Ive track ing the sun both east to west and throughout the seas ons. The adva ntage of this con cept was a more efficie nt harvesti ng of solar en ergy. The third con cept was to only track throughout the seas ons. This would provide small efficie ncy gains but no wh

27、ere n ear the gain provided by track ing east to west. The differe nt structures we came up with to accomplish track ing moti on in cluded a rotati ng cen ter axle with attached pan els, hydraulic or motorized lifts which would move the main panel in the directi on of the sun, and a robotic arm whic

28、h would tur n to face the sun. The clear efficie ncy gains coupled with the simplicity of desig n of the un i-axial track ing system and the existe nee of usable parts (i.e. motor and axle) for the rotat ing cen ter axle structure, led us to the choice of the East to West track ing, rotat ing cen te

29、r axle con cept. 3.2 Structure Once the method of moti on was chose n, it was n ecessary to gen erate con cepts for the structural support of the axle. Support could be provided by the tria ngular prismatic structure which was attempted by the previous Smart House solar tracker group or through the

30、use of colu mns which would support the axis on either side. While the prismatic structure prese nted the adva ntage of mobility and an exist ing frame, the colu mns would have provided us with ease of con struct ion, simple geometric con siderati ons, and ease of prospective mounting on the roof. D

31、ue to the heighte ned in te nsity of time con siderati ons, the previous finan cial commitme nt to the prismatic structure by Smart House, and our limited budget, the presenceof the pre-existing frame proved to be the most importa nt factor in decid ing on a structure. Due to these factors we decide

32、d to work within the frame which was provided to us from the previous Solar Tracker group. 3.2 Tracking Motion Once the structural support was fin alized we n eeded to decide on a mea ns to actualize this moti on. We decided betwee n sen sed moti on, which would sense the sun?s positi on and move to

33、 follow it, and continuous clock type motion, which would track the sun based on its pre-determined position in the sky. We chose the concept of continuous motion based on its perceived accuracy and the existe nee of known timi ng tech no logy. During the evaluati on stage, however, we realized that

34、 con ti nu ous moti on would prove difficult. One reas on was the in ability to draw con sta nt voltage and curre nt from the solar pan els n ecessary to sustai n con siste nt motio n, result ing in the n ecessity for sensing the rotati on positi on to compe nsate. Con ti nu ous moti on also require

35、d n early con sta nt power throughout the day, which would require a mecha nism to store power. Aside from these considerations, the implementation of a timing circuit and location sensing device seemeddaunting. After consulting Dr. Rhett George, we decided on a device using two pan els and shadi ng

36、 for sen sed moti on. 4. Analysis and Embodiment 4.1 Structure Geometry The geometry of the frame was created in order to allow the solar pan els to absorb light efficie ntly. This was done by allowi ng rotati on in the east-west directi on for track ing the sun daily and a 36 inclination (Durham?s

37、latitude) towards the south. Because this frame was designed to be placed on a roof with a slope of 25 , the actual incline of the frame was made to be 11 The geometry of the existing platform structure was modified. This was done in order to in corporate the results from the Clear Day Model supplie

38、d to us by Dr. Kni ght. This model led to the con clusi on that the platform should track to up to 60 in both direct ion sof horiz on tai. Thus, the an gle range of the frame had to be in creased. The sides of the frame were brought in to in crease the allowable an gle of rotati on, and they were br

39、ought in proporti on ally to mai ntai n the in cli nati on an gle of 11 Also, crosspieces were moved to the in side of the frame to allow greater rotati on of the platform before it came into con tact with the support structure. The pan els used for sensing and poweri ng rotati on were placed on the

40、 pla ne of the platform. Mirrors were placed perpendicular to and in between the panelsto shade one and amplify the other in order to produce a differe nee to power the motor. The sensing pan els were placed outside the platform area to mai ntai n the largest area possible for collect ing pan els. A

41、 third sensing panel was moun ted n early vertical and facing east to aid rotati on back towards the sun in the morning. This panel was attached to the frame un der the platform, so that duri ng most of the day, it?s shaded with minimal effects on sen sed rotatio n. Mi ni mizi ng the torques on the

42、motor was a main concern in order to mini mize the motor power n eeded. The platform desig ned for the placeme nt of the collecti ng solar pan els was placed un der the rotati onal shaft so that the pan els would be alig ned with it the rotati onal axis. Since the mai n pan els comprise the majority

43、 of the weight putt ing these in the pla ne of the rotati onal axis reduces torque on the shaft. The sensing pan els were placed symmetrically about the axis of rotatio n in order to preve nt additi onal torque on the motor. The third panel was attached to the frame in stead of the platform or rotat

44、i onal shaft so as to also avoid any torque. 4.2 Materials Materials selection for most of the frame was simple because it had already been con structed. The mirrors used for the amplificati on and shad ing of the sensing pan els were also already purchased and available for use. Additi onal parts f

45、or attachme nt of the pan els and mirrors to the frame were take n from the scrap pieces available in the mach ine shop. In our selecti on of sensing pan els, size and power n eeded to be bala need effectively. The pan els were to be as small as possible in order to add mini mai stress and weight to

46、 the frame but also n eeded to be powerful eno ugh to power the rotatio n of the platform. Therefore, the most powerful of the in termediate sized pan els available were selected. The pan els purchased also appeared to be the most reliable of our opti ons. 4.3 Drive Mechanism After designing a proto

47、type and testing it, the motor purchased and used by the previous solar tracker group was slipping. It was removed, and the installation of a gear system with another simple motor was suggested and attempted. Professor Knight supplied some gears as well as some belts and pulleys. One end of the shaf

48、t was lathed so that one of the pulleys could be set on it, and spacers were bought so that a 6V motor we had available could power ano ther pulley. These pulleys were to be conn ected by a belt. This motor dem on strated in sufficie nt strength to turn the rotational shaft. The original motor, once

49、 detached, was taken apart and exam in ed. Itappeared to be work ing aga in so a new pulley was purchased to fit it and was attached in the place of the 6V motor. 5. Detailed Design 5.1 Frame The frame was desig ned from one inch square alu minum tub ing, and a five foot long, two inch square tube f

50、or the axle. It is con structed with a rigid base and tria ngular prismatic frame with side support ing bars that provide stability. The end of the axle is attached to a system of pulleys which are drive n by the motor. It is easily tran sported by removing the sides of the base and foldi ng the str

51、ucture. 5.2 Sensor Our sensing pan els are bolted to the bottom of the main solar panel frame and braced undern eath with half inch L-brackets. The mirrors are attached to the in side of the sensing pan els and braced by L-brackets as well. The whole structure attaches easily to the main panel frame

52、 which is attached to the main axle using four 2-inch U-bolts. A third panel is bolted to the structure to return the main pan els direct ion towards the horiz on of sun rise. 5.3 How the Sensor Works Our sen sor creates moveme nt of the motor by shadi ng one of the pan els and amplify ing the other

53、 whe n the system is not directly faci ng the sun. The two sensing pan els are moun ted parallel to the mai n pan els symmetrically about the cen ter axle with two mirrors in betwee n them. The shad ing on one of the pan els creates high impeda nee, while the amplified panel powers the motor. This h

54、appe ns un til the pan els receive the same amount of sun light and bala nee each other out (i.e. whe n the sensing pan els and main pan els are facing the sun.). We in itially attempted using a series con figurati on to take adva ntage of the voltage differe nee whe n one of the pan els was shaded

55、(Appe ndix C). This differe nee, however, was not large eno ugh to drive the motor. We subseque ntly attempted a parallel con figurati on which would take adva ntage of the impeda nee of the shaded panel (Appendix C) and provide the current needed to drive the motor. Once the sensing mecha nism has

56、rotated from sun rise to sun set, the third pan el, which is usually shaded, uses sun light from the sun rise of the n ext day to power the motor to retur n the pan els towards the direct ion of the sun. 6. Prototype Testing In itial test ing was done using just the sensing comp onent and a 6V motor

57、. The pan els were tilted by hand to create shad ing and amplificati on. A series eon figurati on of the sensing pan els was in itially tested and proved in effective. Data acquisiti on showed a maximum of a 2V differe nee across the motor, which was in sufficie nt to power it. Upon test ing the pan

58、 els in dividually, it was discovered that the ope n voltage across each in dividual panel would on ly vary betwee n 21.5V and 19.5V whe n fully amplified and fully shaded, respectively. The curre nt running through each pan el, however, was see n to fluctuate betwee n n early 0 amps whe n shaded, u

59、p to 0.65 amps whe n fully amplified. Therefore, in order to take adva ntage of the in crease in impeda nee of the solar pan els due to shad ing, we chose to put our sensing pan els in parallel with each other and the motor. Tests with this con figurati on turned the motor in one directi on, stopped

60、 whe n the sensing pan els were n early perpe ndicular to the sun, and reversed direct ion as the pan els rotated past perpe ndicular. We found the an gle range n ecessary to stop the motor to be very small. It was also observed that the pan els rotated to slightly past perpe ndicular whe n they cea