本次澳洲代写是一个太阳能系统设计和数据分析的**物理代写**assignment

In the previous assignment, you determined the total area required for a solar farm at your

sites to produce 50 MW of electricity per year. Your employer recently heard about a potential

competitor who is designing a similar solar farm, they are designing a cooling system to

reduce the operating temperature of the solar panels. Cooling water is pumped over the top

surface of the solar panel, flowing over the surface as a “free film” of liquid. The cooling

water is available from nearby river, with an average temperature of 22°C, and a pump is used

to supply a mass flowrate of 1.2 kg/s water to each panel. The surface temperature of the solar

panel is to be maintained at ≤ 30°C. The dimensions of the solar panel are unchanged from

your Assignment II.

Investigate the rate of evaporation from the free-film cooling system

A. Draw a clear diagram of the mass balance for the free-film cooling system over the

solar panel, including all related assumptions. (5 marks)

B. The location of the solar farm proposed for this assignment is the same as your

Assignment II. Using the Bureau of Meteorology, identify key data to be used for

mass balance calculations; you will need to collect data to represent both mid-

summer (hottest time of the year) and mid-winter (coolest time of the year) so that

you can perform your calculations with both extremes in mind. Carefully reference

your data source and include any assumptions made. (8 marks)

For questions C – E below, show hand calculations for one condition (i.e. mid-summer or

mid-winter), and include an Excel spreadsheet showing the solution for both mid-summer

and mid-winter conditions. From a discussion with your employer, it is not clear whether or

not this evaporation problem is better analysed as a convective problem or a stagnant film

diffusion problem.

C. Estimate the convective mass transfer coefficients, km, for the free-film cooling

system for a solar panel at your site, assuming either forced or natural convection,

and determine the evaporation rate based on convective analysis. (14 marks)

D. Estimate the evaporation rate for the free-film cooling system assuming stagnant film

diffusion. The frame holding the solar panels is used to help direct the flow of water,

such that there is a stagnant air film above the water of ~1 cm. Based on your answers

to C and D, which approach makes more sense? (12 marks)

E. Will the evaporative mass transfer rate affect the outlet rate of water from the panel

surface? (4 marks)

F. The day-to-day variations in ambient conditions might dramatically impact the

evaporation rate for this system. Use graphs to show the effect of varying wind

velocity and relative humidity on the evaporative rate. Graphs can be produced in

Excel, but provide explanations to describe the results. (10 marks)

G. Calculate the evaporative heat rate (W) associated with evaporation of water from

the free-film. Explain in words how this would affect the energy balance and power

generation capacity for the solar farm, in comparison to an alternative approach of

back-surface panel cooling whereby cooling jacket was installed at the back of the

panel. Would you recommend jacketed cooling system or free-film approach?

Explain your answer in terms of fundamental heat and mass transfer concepts. Limit

your answer to a maximum of 150 words. (7 marks)