EBK THERMODYNAMICS: AN ENGINEERING APPR
9th Edition
ISBN: 8220106796979
Author: CENGEL
Publisher: YUZU
expand_more
expand_more
format_list_bulleted
Videos
Question
Chapter 11.10, Problem 98P
To determine
Why semiconductor materials are preferable to metals in thermoelectric refrigerators.
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
Using the moment-area theorems, determine a) the rotation at A, b) the deflection at L/2, c) the deflection at L/4.
(Hint: Use symmetry for Part a (θA= - θB, or θC=0), Use the rotation at A for Parts b and c. Note that all deformations
in the scope of our topics are small deformation and for small θ, sinθ=θ).
Distilled water is being cooled by a 20% propylene glycol solution in a 1-1/U counter flow plate
and frame heat exchanger. The water enters the heat exchanger at 50°F at a flow rate of 86,000
lbm/h. For safety reasons, the water outlet temperature should never be colder than 35°F. The
propylene glycol solution enters the heat exchanger at 28°F with a flow rate of 73,000 lbm/h. The
port distances on the heat exchanger are Lv = 35 in and Lh = 18 in. The plate width is Lw = 21.5
2
in. The plate thickness is 0.04 in with a plate pitch of 0.12 in. The chevron angle is 30° and the
plate enlargement factor is 1.17. All ports have a 2 in diameter. The fouling factor of the propylene
glycol solution can be estimated as 2 ×10−5 h-ft2-°F/Btu.
a. Determine the maximum number of plates the heat exchanger can have while ensuring
that the water outlet temperature never drops below 35°F.
b. Determine the thermal and hydraulic performance of the heat exchanger with the specified
number of plates.…
Liquid pentane is flowing in the shell of a shell and tube heat exchanger at a rate of 350,000lbm/hr and an average temperature of 20°F. The shell has a diameter of 27 in and a length of 16ft. The tubes in the heat exchanger are ¾-in 15 BWG tubes on a 1-in triangular pitch. The purposeof this problem is to investigate how the number of baffles impacts the heat transfer and thepressure drop on the shell side of the heat exchanger. Calculate the shell-side convective heattransfer coefficient and pressure drop for the case where the heat exchanger has 10 baffles. Repeatthe calculation for 20 baffles. Then determine thea. Ratio of the shell-side convective heat transfer coefficient for the 20-baffle heat exchangerto the 10-baffle heat exchangerb. Ratio of the shell-side pressure drop for the 20-baffle heat exchanger to the 10-baffle heatexchangerc. If the optimum baffle spacing is somewhere between 0.4Ds and 0.6Ds, how many baffleswould you recommend for this heat exchanger? What are the…
Chapter 11 Solutions
EBK THERMODYNAMICS: AN ENGINEERING APPR
Ch. 11.10 - Why do we study the reversed Carnot cycle even...Ch. 11.10 - Why is the reversed Carnot cycle executed within...Ch. 11.10 - A steady-flow Carnot refrigeration cycle uses...Ch. 11.10 - Refrigerant-134a enters the condenser of a...Ch. 11.10 - Does the ideal vapor-compression refrigeration...Ch. 11.10 - Why is the throttling valve not replaced by an...Ch. 11.10 - In a refrigeration system, would you recommend...Ch. 11.10 - Does the area enclosed by the cycle on a T-s...Ch. 11.10 - Consider two vapor-compression refrigeration...Ch. 11.10 - It is proposed to use water instead of...
Ch. 11.10 - The COP of vapor-compression refrigeration cycles...Ch. 11.10 - A 10-kW cooling load is to be served by operating...Ch. 11.10 - An ice-making machine operates on the ideal...Ch. 11.10 - An air conditioner using refrigerant-134a as the...Ch. 11.10 - An ideal vapor-compression refrigeration cycle...Ch. 11.10 - A refrigerator operates on the ideal...Ch. 11.10 - A refrigerator uses refrigerant-134a as the...Ch. 11.10 - An ideal vapor-compression refrigeration cycle...Ch. 11.10 - A refrigerator uses refrigerant-134a as its...Ch. 11.10 - A refrigerator uses refrigerant-134a as the...Ch. 11.10 - A commercial refrigerator with refrigerant-134a as...Ch. 11.10 - The manufacturer of an air conditioner claims a...Ch. 11.10 - Prob. 24PCh. 11.10 - How is the second-law efficiency of a refrigerator...Ch. 11.10 - Prob. 26PCh. 11.10 - Prob. 27PCh. 11.10 - Prob. 28PCh. 11.10 - Bananas are to be cooled from 28C to 12C at a rate...Ch. 11.10 - A vapor-compression refrigeration system absorbs...Ch. 11.10 - A room is kept at 5C by a vapor-compression...Ch. 11.10 - Prob. 32PCh. 11.10 - A refrigerator operating on the vapor-compression...Ch. 11.10 - When selecting a refrigerant for a certain...Ch. 11.10 - A refrigerant-134a refrigerator is to maintain the...Ch. 11.10 - Consider a refrigeration system using...Ch. 11.10 - A refrigerator that operates on the ideal...Ch. 11.10 - A heat pump that operates on the ideal...Ch. 11.10 - Do you think a heat pump system will be more...Ch. 11.10 - What is a water-source heat pump? How does the COP...Ch. 11.10 - A heat pump operates on the ideal...Ch. 11.10 - Refrigerant-134a enters the condenser of a...Ch. 11.10 - A heat pump that operates on the ideal...Ch. 11.10 - The liquid leaving the condenser of a 100,000...Ch. 11.10 - Reconsider Prob. 1144E. What is the effect on the...Ch. 11.10 - A heat pump using refrigerant-134a heats a house...Ch. 11.10 - A heat pump using refrigerant-134a as a...Ch. 11.10 - Reconsider Prob. 1148. What is the effect on the...Ch. 11.10 - Prob. 50PCh. 11.10 - How does the COP of a cascade refrigeration system...Ch. 11.10 - Consider a two-stage cascade refrigeration cycle...Ch. 11.10 - Can a vapor-compression refrigeration system with...Ch. 11.10 - Prob. 54PCh. 11.10 - A certain application requires maintaining the...Ch. 11.10 - Prob. 56PCh. 11.10 - Repeat Prob. 1156 for a flash chamber pressure of...Ch. 11.10 - Prob. 59PCh. 11.10 - A two-stage compression refrigeration system with...Ch. 11.10 - A two-stage compression refrigeration system with...Ch. 11.10 - A two-evaporator compression refrigeration system...Ch. 11.10 - A two-evaporator compression refrigeration system...Ch. 11.10 - Repeat Prob. 1163E if the 30 psia evaporator is to...Ch. 11.10 - Consider a two-stage cascade refrigeration cycle...Ch. 11.10 - How does the ideal gas refrigeration cycle differ...Ch. 11.10 - Prob. 67PCh. 11.10 - Devise a refrigeration cycle that works on the...Ch. 11.10 - How is the ideal gas refrigeration cycle modified...Ch. 11.10 - Prob. 70PCh. 11.10 - How do we achieve very low temperatures with gas...Ch. 11.10 - An ideal gas refrigeration system operates with...Ch. 11.10 - Air enters the compressor of an ideal gas...Ch. 11.10 - Repeat Prob. 1173 for a compressor isentropic...Ch. 11.10 - An ideal gas refrigeration cycle uses air as the...Ch. 11.10 - Rework Prob. 1176E when the compressor isentropic...Ch. 11.10 - A gas refrigeration cycle with a pressure ratio of...Ch. 11.10 - A gas refrigeration system using air as the...Ch. 11.10 - An ideal gas refrigeration system with two stages...Ch. 11.10 - Prob. 81PCh. 11.10 - Prob. 82PCh. 11.10 - What are the advantages and disadvantages of...Ch. 11.10 - Prob. 84PCh. 11.10 - Prob. 85PCh. 11.10 - Prob. 86PCh. 11.10 - Prob. 87PCh. 11.10 - Heat is supplied to an absorption refrigeration...Ch. 11.10 - An absorption refrigeration system that receives...Ch. 11.10 - An absorption refrigeration system receives heat...Ch. 11.10 - Heat is supplied to an absorption refrigeration...Ch. 11.10 - Prob. 92PCh. 11.10 - Prob. 93PCh. 11.10 - Consider a circular copper wire formed by...Ch. 11.10 - An iron wire and a constantan wire are formed into...Ch. 11.10 - Prob. 96PCh. 11.10 - Prob. 97PCh. 11.10 - Prob. 98PCh. 11.10 - Prob. 99PCh. 11.10 - Prob. 100PCh. 11.10 - Prob. 101PCh. 11.10 - Prob. 102PCh. 11.10 - A thermoelectric cooler has a COP of 0.18, and the...Ch. 11.10 - Prob. 104PCh. 11.10 - Prob. 105PCh. 11.10 - Prob. 106PCh. 11.10 - Rooms with floor areas of up to 15 m2 are cooled...Ch. 11.10 - Consider a steady-flow Carnot refrigeration cycle...Ch. 11.10 - Consider an ice-producing plant that operates on...Ch. 11.10 - A heat pump that operates on the ideal...Ch. 11.10 - A heat pump operates on the ideal...Ch. 11.10 - A large refrigeration plant is to be maintained at...Ch. 11.10 - Repeat Prob. 11112 assuming the compressor has an...Ch. 11.10 - An air conditioner with refrigerant-134a as the...Ch. 11.10 - A refrigerator using refrigerant-134a as the...Ch. 11.10 - Prob. 117RPCh. 11.10 - An air conditioner operates on the...Ch. 11.10 - Consider a two-stage compression refrigeration...Ch. 11.10 - A two-evaporator compression refrigeration system...Ch. 11.10 - The refrigeration system of Fig. P11122 is another...Ch. 11.10 - Repeat Prob. 11122 if the heat exchanger provides...Ch. 11.10 - An aircraft on the ground is to be cooled by a gas...Ch. 11.10 - Consider a regenerative gas refrigeration cycle...Ch. 11.10 - An ideal gas refrigeration system with three...Ch. 11.10 - Prob. 130RPCh. 11.10 - Derive a relation for the COP of the two-stage...Ch. 11.10 - Prob. 133FEPCh. 11.10 - Prob. 134FEPCh. 11.10 - Prob. 135FEPCh. 11.10 - Prob. 136FEPCh. 11.10 - Prob. 137FEPCh. 11.10 - An ideal vapor-compression refrigeration cycle...Ch. 11.10 - Prob. 139FEPCh. 11.10 - An ideal gas refrigeration cycle using air as the...Ch. 11.10 - Prob. 141FEPCh. 11.10 - Prob. 142FEP
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, mechanical-engineering and related others by exploring similar questions and additional content below.Similar questions
- The evaporator of a vapor compression refrigeration cycle utilizing R-123 as the refrigerant isbeing used to chill water. The evaporator is a shell and tube heat exchanger with the water flowingthrough the tubes. The water enters the heat exchanger at a temperature of 54°F. The approachtemperature difference of the evaporator is 3°R. The evaporating pressure of the refrigeration cycleis 4.8 psia and the condensing pressure is 75 psia. The refrigerant is flowing through the cycle witha flow rate of 18,000 lbm/hr. The R-123 leaves the evaporator as a saturated vapor and leaves thecondenser as a saturated liquid. Determine the following:a. The outlet temperature of the chilled waterb. The volumetric flow rate of the chilled water (gpm)c. The UA product of the evaporator (Btu/h-°F)d. The heat transfer rate between the refrigerant and the water (tons)arrow_forwardThe blade support of a hacksaw is subject to compression when a blade is installed and tightened. What is the state of stress (total combined stress) at A in MPa if the compression in the support is 1,524 N. Note: pay close attention to what is compression and what is tension and use a negative sign for the former. 100 mm 8 mm 3 mm 75 mm A 8 mm 3 mm B 50 mmarrow_forwardThe answer is not 4.378 ft/sarrow_forward
- The answer is not 0.293 marrow_forwardplease first help me solve this problem find the line of action and them help to find the forces like for example {fx= fy= mz= and determine the shear force in the nailsarrow_forwardAn open channel of square cross section had a flowrate of 17.2 ft³/s when first used. After extended use, the channel became 0.6-filled with silt. Determine the flowrate for this silted condition. Assume the Manning coefficient is the same for all the surfaces. Qs= ! ft³/sarrow_forward
- (Manning equation) The triangular flume shown in the figure below is built to carry its design flowrate, Qo, at a depth of 0.991 m as is indicated. If the flume is to be able to carry up to twice its design flowrate, Q = 2Qo, determine the freeboard, I, needed. ✓ -90°- 0.991 m i marrow_forwardWater flows in a 2-ft-wide rectangular channel at a rate of 10 ft³/s. If the water depth downstream of a hydraulic jump is 2.5 ft, determine (a) the water depth upstream of the jump, (b) the upstream and (c) downstream Froude numbers, and (d) the head loss across the jump. (a) y₁ = i (b) Fr₁ = i (c) Fr₂ = i (d) h₁ = ft ftarrow_forwardA hydraulic jump at the base of a spillway of a dam is such that the depths upstream and downstream of the jump are 0.8 and 3.2 m, respectively (see the Video). If the spillway is 12 m wide, what is the flowrate over the spillway? Q= i m³/sarrow_forward
- (Manning equation) Water flows in a rectangular channel of width b at a depth of b/2. Determine the diameter of a circular channel (in terms of b) that carries the same flowrate when it is half-full. Both channels have the same Manning coefficient, n, and slope. barrow_forward(Manning equation) A weedy irrigation canal of trapezoidal cross section is to carry 20 m³/s when built on a slope of 0.60 m/km. If the sides are at a 45° angle and the bottom is 8 m wide, determine the width of the waterline at the free surface. i marrow_forwardWater flows in a 1.2-m-diameter finished concrete pipe so that it is completely full and the pressure is constant all along the pipe. If the slope is So = 0.0073, (a) determine the flowrate by using open-channel flow methods. Compare this result with (b) that obtained using the pipe flow methods of Chapter 8 (Use Colebrook formula, Table 8.1, Table 10.1 and assume that Re > 10º). (a) Q = i (b) Q = i m³/s m³/sarrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
Refrigeration and Air Conditioning Technology (Mi...Mechanical EngineeringISBN:9781305578296Author:John Tomczyk, Eugene Silberstein, Bill Whitman, Bill JohnsonPublisher:Cengage Learning
Refrigeration and Air Conditioning Technology (Mi...
Mechanical Engineering
ISBN:9781305578296
Author:John Tomczyk, Eugene Silberstein, Bill Whitman, Bill Johnson
Publisher:Cengage Learning
The Refrigeration Cycle Explained - The Four Major Components; Author: HVAC Know It All;https://www.youtube.com/watch?v=zfciSvOZDUY;License: Standard YouTube License, CC-BY