Question

Which of the following is NOT true?

Select one:

a. The f-chart design method is a correlation of the results of many hundreds of thermal performance simulations of solar heating systems performed with TRNSYS.

b. The f-chart design method can quickly estimate the long-term performance of solar energy systems of standard configurations

c. The f-chart design method can be used for a standard air based solar heating system

d. The f-chart design method is used to design commercial-type large scale solar heating systems

Question 2

For the f-chart method, the two dimensionless groups X and Y increase as, (there may be more than one answer)

Select one or more:

a. The collector area increases

b. Ambient temperature increases

c. Collector overall loss coefficient decreases

d. The collector heat exchanger efficiency correction factor increases

Question 3

In the f-chart method, the solar collector can be which of the following (indicate all correct answers).

Select one or more:

a. Evacuated tube collector

b. Concentrating collector

c. compound parabolic collector

d. Flat plate collector

Question 4

For a 25 m² solar collector, X and Y are calculated to be 0.782 and 0.211. If the collector area increases to 50 m² (other parameters kept the same), what will be the values of X and Y?

Select one:

a. 1.564 and 0.211

b. 0.782 and 0.211

c. 1.564 and 0.422

d. 0.782 and 0.422

Question 5

For a standard liquid-based solar heating system with the values of X and Y are 1.56 and 0.41, what is the value of f?

Select one:

a. 0.15

b. 0.36

c. 0.28

d. 0.21

Which of the following are NOT needed as input data in f-chart design method?

Select one or more:

a. The monthly load required to heat a building and its service water

b. The collector performance parameters obtained from standard collector tests

c. The monthly average temperature and daily radiation

d. The control strategy

Question 7

Given the table above, what is the annual fraction of load covered by the solar energy system?

Select one:

a. 35.3 %

b. 29.5 %

c. 26.6%

d. 38.1%

Answer 1

Question 1

Which of the following is NOT true?

Select one:

a. The f-chart design method is a correlation of the results of many hundreds of thermal performance simulations of solar heating systems performed with TRNSYS.

b. The f-chart design method can quickly estimate the long-term performance of solar energy systems of standard configurations

c. The f-chart design method can be used for a standard air based solar heating system

d. The f-chart design method is used to design commercial-type large scale solar heating systems

Question 2

For the f-chart method, the two dimensionless groups X and Y increase as, (there may be more than one answer)

Select one or more:

a. The collector area increases

b. Ambient temperature increases

c. Collector overall loss coefficient decreases

d. The collector heat exchanger efficiency correction factor increases

When ambient temperature increases, the X & Y decreases. And as Collector overall loss coefficient decreases, the X & Y decreases.

Question 3

In the f-chart method, the solar collector can be which of the following (indicate all correct answers).

Select one or more:

a. Evacuated tube collector

b. Concentrating collector

c. compound parabolic collector

d. Flat plate collector

Question 4

For a 25 m2 solar collector, X and Y are calculated to be 0.782 and 0.211. If the collector area increases to 50 m2 (other parameters kept the same), what will be the values of X and Y?

Select one:

a. 1.564 and 0.211

b. 0.782 and 0.211

c. 1.564 and 0.422

d. 0.782 and 0.422

X and Y are directly proportional to Area of collector, therefore if area of collector is doubled then value of X & Y are both doubled.

Question 5

For a standard liquid-based solar heating system with the values of X and Y are 1.56 and 0.41, what is the value of f?

Select one:

a. 0.15

b. 0.36

c. 0.28

d. 0.21

f = 1.029Y - 0.065X - 0.245Y2 + 0.0018X2 + 0.0215Y3  

f = 1.029 (0.41) - 0.065 (1.56) - 0.245(0.41)2 + 0.0018(1.56)2 + 0.0215 (0.41)3  

f = 0.285

Ans C

Please rate my answer. Thank You.