Chapter 11, Problem 11.1DP

i. Sketch and explain the working operation of a Dish type solar cooker? ii. With the help of a schematic diagram explain the operation of active type solar water heater?

In an absorption refrigerator, the energy driving the process is sllPplied not as work, but as heat from a gas flame. (Such refrigerators commonly use propane as fuel, and are used in locations where electricity is unavailable. *) Let us define the following symbols, all taken to be positive by definition:                     Qf = heat input from flame                      Qe = heat extracted from inside refrigerator                      Qr = waste heat expelled to room                      Tf = temperature of flame                                         Te temperature inside refrigerator                                           Tr = room temperature Use the second law of thermodynamics to derive an upper limit on the COP, in terms of the temperatures Tf, Te, and Tr alone.

In an absorption refrigerator, the energy driving the process is sllPplied not as work, but as heat from a gas flame. (Such refrigerators commonly use propane as fuel, and are used in locations where electricity is unavailable. *) Let us define the following symbols, all taken to be positive by definition:                     Qf = heat input from flame                      Qe = heat extracted from inside refrigerator                      Qr = waste heat expelled to room                      Tf = temperature of flame                                         Te temperature inside refrigerator                                           Tr = room temperature Explain why the "coefficient of performance" (COP) for an absorption refrigerator should be defined as Qc/Qf.

Question 1 A nuclear power plant is rated at 500 MW (it provides this amount of useful power). During operation, the hot core is at 577 °C , and the average temperature of the cooling water is 27 °C Part A What is the maximum available thermal efficiency for these temperatures? Part B This plant is rated at the lower efficiency of 50%. For cooling, it takes in seawater at 17 C and gives it back at 37 °C (so that the average is indeed 27 °C). How many kilograms of water is needed per second?

Refrigerationa.) Explain why you can’t cool down your kitchen by leaving your refrigerator or freezer door open with your refrigerator plugged in for an extended period of time.b.) The condenser of a home refrigerator is commonly underneath the appliance, thus the condensing refrigerant exchanges heat with household air, which averages 70oF. It is proposed toreconfigure a refrigerator so that the condenser is in the garage, where the average yearly temperature is about 50oF. Assume a freezer temperature of 0oF, a minimum temperature difference of 10K for heat transfer, and an actual coefficient of performance of 60% that of a Carnot cycle. Calculate the Coefficient of Performance for both configurations and discuss the pros and cons of this proposal.c.) Which is the most effective way to increase the coefficient of performance of a Carnot refrigerator: to increase TC with TH held constant or to decrease TH with TC held constant? Justify mathematically. For a real refrigerator, do…

Assume that the average solar insolation in Jamaica is 6500Wh/m² per day and its land area is 10,992 km². Consider that 3% of the land area could be covered by photovoltaic (PV) solar farms and 80% of the area of the solar farm is covered with PV modules with a conversion efficiency of 20%. In this case how much energy expressed in kWh/day could be produced using PV farms? Part B With the aid of diagrams, explain the similarities and differences between a fuel fired steam plant and a combined cycle gas plant. Label all major sections of your diagrams. With the aid of a simple sketch, explain how the following angles affect the location of the sun relative to the earth's sky. • Solar declination Solar azimuth Altitude 1

Discuss briefly the different types of heat loads which have to be taken into account in order to estimate the total heat load of a large restaurant for summer air conditioning?

Pls. Answer thank you! An air-conditioning system is used to maintain a house at 65°F when the temperature outside is 85°F. The house is gaining heat through the walls and windows at a rate of 1250 Btu/min, and the heat generation rate within the house from people, lights, and appliances amounts to 350 Btu/min. Determine the minimum power input required for this air-conditioning system

An increase in the natural greenhouse effect that leads to heating of the earth is called _____.