An Introduction to Thermal Physics
1st Edition
ISBN: 9780201380279
Author: Daniel V. Schroeder
Publisher: Addison Wesley
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Textbook Question
Chapter 4.4, Problem 30P
Consider a household refrigerator that uses HFC-134a as the refrigerant, operating between the pressures of 1.0 bar and 10 bars.
(a) The compression stage of the stage of the cycle begins with saturated vapor at 1 bar and ends at 10 bars. Assuming that the entropy is constant during compression, find the approximate temperature of the vapor after it is compressed. (You’ll have to do an interpolation between the values given in Table 4.4)
(b) Determine the enthalpy at each of the points 1, 2, 3, and 4, and calculate the coefficient of performance. Compare to the COP of a Carnot refrigerator operating between the same reservoir temperatures. Does this temperature range seem reasonable for a household refrigerator? Explain briefly.
(c) What fraction of the liquid vaporizes during the throttling step?
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Chapter 4 Solutions
An Introduction to Thermal Physics
Ch. 4.1 - Prob. 1PCh. 4.1 - At a power plant that produces 1 GW ( 109 watts)...Ch. 4.1 - A power plant produces 1 GW of electricity, at an...Ch. 4.1 - It has been proposed to use the thermal gradient...Ch. 4.1 - Prove directly (by calculating the heat taken in...Ch. 4.1 - To get more than an infinitesimal amount of work...Ch. 4.2 - Why must you put an air conditioner in the window...Ch. 4.2 - Can you cool off your kitchen by leaving the...Ch. 4.2 - Prob. 9PCh. 4.2 - Suppose that heat leaks into your kitchen...
Ch. 4.2 - What is the maximum possible COP for a cyclic...Ch. 4.2 - Explain why an ideal gas taken around a...Ch. 4.2 - Under many conditions, the rate at which heat...Ch. 4.2 - Prob. 14PCh. 4.2 - In an absorption refrigerator the energy driving...Ch. 4.2 - Prob. 16PCh. 4.2 - Prob. 17PCh. 4.3 - Prob. 18PCh. 4.3 - The amount of work done by each stroke of an...Ch. 4.3 - Derive a formula for the efficiency of the Diesel...Ch. 4.3 - The ingenious Stirling engine is a true heat...Ch. 4.3 - A small-scale steam engine might operate between...Ch. 4.3 - Prob. 23PCh. 4.3 - Calculate the efficiency of a Rankine cycle that...Ch. 4.3 - In a real turbine, the entropy of the steam will...Ch. 4.3 - A coal-fired power plant, with parameters similar...Ch. 4.3 - In Table 4.1, why does the entropy of water...Ch. 4.3 - Imagine that your dog has eaten the portion of...Ch. 4.4 - Liquid HFC-134a at its boiling point at 12 bars...Ch. 4.4 - Consider a household refrigerator that uses...Ch. 4.4 - Suppose that the throttling valve in the...Ch. 4.4 - Suppose you are told to design a household air...Ch. 4.4 - Prob. 33PCh. 4.4 - Consider an ideal Hampson-Linde cycle in which no...Ch. 4.4 - The magnetic field created by a dipole has a...Ch. 4.4 - Prob. 36PCh. 4.4 - A common (but imprecise) way of stating the third...
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