Problem 9-1: An iron-constantan thermocouple is placed in a moving air stream in aduct, as shown in the figure below. The air flows at 70 m/s. The emissivity of thethermocouple is 0.5 and the recovery factor is 0.6. The wall temperature300°C. The thermocouple reference junction is maintained at 100° C. The emfoutput from the thermocouple is 16 mV.I w-A. Determine the thermocouple junction temperature.B. By considering recovery and radiation errors, estimate the possible value for totalerror in the indicated temperature. Discuss whether this estimate of themeasurement error is conservative and why, or why not. The heat-transfercoefficient may be taken as 100 W/(m² K).T = 260°CwAirU = 200 ft/sTrefVoltage

Step 1: Step 2: Step 3: Step 4: Step 5:

Answered: Problem 9-1: An iron-constantan…

Principles of Heat Transfer (Activate Learning with these NEW titles from Engineering!)

8th Edition

ISBN:9781305387102

Author:Kreith, Frank; Manglik, Raj M.

Publisher:Kreith, Frank; Manglik, Raj M.

Chapter8: Natural Convection

Section: Chapter Questions

Problem 8.3DP

See similar textbooks

Similar questions

A Thomas meter is located in an air duct of 2 sq ft cross-sectional area. The air weighs 0.083 lb per cu ft, and its specific heat is 0.24. Assume a controlled temperature differential of 5° and heater potential of 110 volts. Plot the velocity as abscissa and amperage as ordinate for veloc- ity 0 to 300 ft per min. Assume constant amperage of 3, and plot tem- perature difference against velocity. Discuss the curves from the stand- point of accuracy of the system.
2. Two copper-constantan thermocouples with 1 and 2 mm diameters are taken from ambient at 20 °C, and dipped into boiling water at 100 °C. a. Find the time constant for each TC, where Time Constant, t=mc/hA Assume: Density, p = 8500 kg/m3 Specific Heat, c = 400 J/kgK Heat transfer coefficient for the TC's is h = 400 W/m²C. b. Find the output from each thermocouple after 10 seconds in the boiling water. y = Kxo (1-e¹½) Temperature (C) 110 100 90 80 70 60 50 40 30 20 10 0 1 01 L L 2 3 4 5 6 1 L 7 8 Time (s) 9 10 1mm diameter 2mm diameter 1 11 12 13 14
What is the log mean temperature difference in deg C of a double-piped counterflow heat exchanger where a fluid enters at 90 deg C and exits at 50 deg C? Inside the inner pipe, another fluid enters at 20 deg C and exits at 60 deg C. Select the correct response: 35 75 30
1. Figure 1 below shows a stirred tank heating process-with a constant holdup volume. Assume mass flow rate w, of the inlet pipe is constant whereas its temperature T fluctuates but the product temperature T must be maintained within set temperature tolerances about the reference. Heater Figure 1: Stirred heating tank process
a buildiug has the following calculated cooling loads: RSH gain 300 kW RLH gain = 110 kW The space is maintained at the following conditions Room DBT 25°C, Room RH = 55% Outdoor is at 40°C and RH 50%. And 10% by mass of air supplied to the buildings is out door. If the air supplied to the space is not to be at a temperature lower than 18°C. Find (i) Miu amount of air supplied to space in m/sec. (ii) Mass flow rates of return air, exhaust air and out door air (i) Capacity, BPFand sensible heat factor of cooling coil. Given: Condition DBT RH Sp. Humidity Enthalpy °C g.w.v./kg d.a. kJ/kg d.a. outside 40 50 23.6. 100 inside 25 55 10.6 52.5 supply Specitic valume of air supply point 0.836 m³/kg, coil ADP=9°C. 18 41.2
* It required to design a ducting system to condition the building shown in figure (1). The uantity of outdoor is (20%) of supply air. Using information in table, find 1- The sensible and latent load for cooling coil. 2- The quantity and condition of supply air to each place. 3- By using equal pressure drop method, design the rectangular ducting system with maximum height side (600mm). 4- Illustrate the all process on psychometric chart. Outdoor 45 °C db & 30% RH Out let type Celling conditioning indoor conditioning 24 °C db & 50% RH diffuser Number of diffuser 2 for each place 15 kpa 10 kpa 15 kpa By pass factor Apparatus dew point 9°C Ap losses diffuser Ap losses filter Ap losses coil 0.15 R/w 1.5 бm бm бm Room (1) Room (2) RSH=6KW Room (3) 4m RSH=8KW RSH=8KW RLH=2KW RLH=1KW RLH=2KW 2m AHU Mechanical Room (4) RSH=20KW 4m Room RLH=3KW 4m 14m
* It required to design a ducting system to condition the building shown in figure (1). The uantity of outdoor is (20%) of supply air. Using information in table, find 1- The sensible and latent load for cooling coil. 2- The quantity and condition of supply air to each place. 3- By using equal pressure drop method, design the rectangular ducting system with maximum height side (600mm). 4- Illustrate the all process on psychometric chart. Outdoor 45 °C db & 30% RH Out let type Celling conditioning indoor conditioning 24 °C db & 50% RH diffuser Number of diffuser 2 for each place 15 kpa 10 kpa 15 kpa By pass factor Apparatus dew point 9°C Ap losses diffuser Ap losses filter Ap losses coil 0.15 R/w 1.5 6m 6m 6m Room (1) Room (2) Room (3) 4m RSH=8KW RSH=6KW RSH=8KW RLH=2KW RLH=1KW RLH=2KW 2m AHU Mechanical Room (4) RSH=20KW 4m Room RLH=3KW 4m 14m
Inside Diamete r 56 cm 58 mm 58 mm Pass Number of Tubes 1 st 1 2 nd 38 3 rd 30 Crown Sheet Cover True Value = 503 ft² fill up the table Outside Length Heating Diamete Surface r 62 cm 273 cm 64 mm 298 cm 64 mm 304 cm 151 cm Experimental Value = Per Cent Error =
7:24 O t ME 4141L -Controls... Z Encountered error/s: of and for the exclusive use of SLU. Reproduction, storing in a retrieval system, distributing, uploading or posting online, or transmitting in any form ectronic, mechanical, photocopying, recording, or otherwise of any part of this document, without the prior written permission of SLU, is strictly pro Problem #3: Use of 5/2 way valves with spring return Problem: Boxes (or certain production parts) are moved by a double-acting cylinder away from a gravity-feed magazine towards an assembly device. A push button and a pedal switch are to be incorporated in the circuit. The cylinder is to move out when either of these is actuated The return stroke is actuated by the cylinder rod after it reaches the end of the forward stroke. Positional sketch: 19/ 33 ::: II
PROBLEM: VA-34 FROM THE BOOK: ENGINEERING THERMOFLUIDS, M. MASSOUD.
Find frequency and mode shape for the system shown in Fig. 5, using Stodola process. Take m = 1 kg; k = 1000N/m. wwwwww m 2k Fig. 5
A 4 cylinder normally aspirated two stroke piston engine develops a brake mean effective pressure of 8 atm, having a piston stroke of 120 mm, a cylinder bore of 150 mm, a volumetric compression ratio of 7 and operates at 3000rpm in sea-level-standard ambient conditions. The internal efficiency is 80 % . Find the Indicated Power and the charge mass flow rate if the mixture is preheated by 60°C and the charge pressure is 0.9 atm and the exhaust pressure is 1.1 atm (Assume Rc = 0.99 R_air).

SEE MORE QUESTIONS

Recommended textbooks for you

Principles of Heat Transfer (Activate Learning wi…

Mechanical Engineering

ISBN:

9781305387102

Author:

Kreith, Frank; Manglik, Raj M.

Publisher:

Cengage Learning