A solar energy storage compartment contains 1,778 rocks that can approximate 3-inch-diameter spheres. The properties of the rocks are k = 2.2 Btu / h ∙ ft ∙ ºF, α = 0.07 ft2 / h, cp = 0.2 Btu / lbm ° F, and the density is 160 lbm / ft3. How long (in hours) would it take for solar energy to saturate the compartment using 200 ° F air from a solar collector? How much energy (in Btu) is stored in the compartment under these conditions if it is initially at 79 ° F and h = 5 Btu / h ∙ ft2 ∙ ºF?

A solar energy storage compartment contains 1,778 rocks that can approximate 3-inch-diameter spheres. The properties of the rocks are k = 2.2 Btu / h ∙ ft ∙ ºF, α = 0.07 ft2 / h, cp = 0.2 Btu / lbm ° F, and the density is 160 lbm / ft3. How long (in hours) would it take for solar energy to saturate the compartment using 200 ° F air from a solar collector? How much energy (in Btu) is stored in the compartment under these conditions if it is initially at 79 ° F and h = 5 Btu / h ∙ ft2 ∙ ºF?

Refrigeration and Air Conditioning Technology (MindTap Course List)

8th Edition

ISBN:9781305578296

Author:John Tomczyk, Eugene Silberstein, Bill Whitman, Bill Johnson

Publisher:John Tomczyk, Eugene Silberstein, Bill Whitman, Bill Johnson

Chapter2: Matter And Energy

Section: Chapter Questions

Problem 26RQ: How many Btu of heat can be produced by 4 kWh ofelectricity?

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