Electrical Transformers and Rotating Machines
4th Edition
ISBN: 9781337264419
Author: Stephen L. Herman
Publisher: Cengage Learning US
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Textbook Question
Chapter 14, Problem 19RQ
To what is countertorque proportional?
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The wall of a furnace has a thickness of 5 cm and thermal conductivity
of 0.7 W/m-°C. The inside surface is heated by convection with a hot
gas at 402°C and a heat transfer coefficient of 37 W/m²-°C. The
outside surface has an emissivity of 0.8 and is exposed to air at 27°C
with a heat transfer coefficient of 20 W/m²-ºC. Assume that the
furnace is inside a large room with walls, floor and ceiling at 27°C.
Show the thermal circuit and determine the heat flux through the
furnace wall.
h₁
T₁
k
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T.
sur
ho
E
Turbomachienery .
GIven:
vx = 185 m/s, flow angle = 60 degrees, R = 0.5, U = 150 m/s, b2 = -a3, a2 = -b3
Find: velocity triangle , a. magnitude of abs vel leaving rotor (m/s) b. flow absolute angles (a1, a2, a3) 3. flow rel angles (b2, b3) d. specific work done e. use code to draw vel. diagram
Use this code for plot
% plots Velocity Tri. in Ch4
function plotveltri(al1,al2,al3,b2,b3)
S1L = [0 1];
V1x = [0 0];
V1s = [0 1*tand(al3)];
S2L = [2 3];
V2x = [0 0];
V2s = [0 1*tand(al2)];
W2s = [0 1*tand(b2)];
U2x = [3 3];
U2y = [1*tand(b2) 1*tand(al2)];
S3L = [4 5];
V3x = [0 0];
V3r = [0 1*tand(al3)];
W3r = [0 1*tand(b3)];
U3x = [5 5];
U3y = [1*tand(b3) 1*tand(al3)];
plot(S1L,V1x,'k',S1L,V1s,'r',...
S2L,V2x,'k',S2L,V2s,'r',S2L,W2s,'b',U2x,U2y,'g',...
S3L,V3x,'k',S3L,V3r,'r',S3L,W3r,'b',U3x,U3y,'g',......
'LineWidth',2,'MarkerSize',10),...
axis([-1 6 -4 4]), ...
title('Velocity Triangle'), ...
xlabel('x'),ylabel('y'), grid
To save fuel during the heating season it is suggested that glass windows
be covered at night with a 1.2 cm layer of polystyrene. Estimate the
percent savings in energy and discuss the feasibility of this idea. Show
the thermal circuit with and without the insulation panel. Consider a typical
case of 0.2 cm thick window glass with inside and outside heat transfer
coefficients of 6 and 32 W/m²-ºC.
Lg←←Lp
h
T₁
T。
g
kp
insulation panel
Chapter 14 Solutions
Electrical Transformers and Rotating Machines
Ch. 14 - Prob. 1RQCh. 14 - What type of voltage is produced in all rotating...Ch. 14 - What are the three types of armature windings?Ch. 14 - What type of armature winding would be used for a...Ch. 14 - What are interpoles, and what is their purpose?Ch. 14 - How are interpoles connected in relation to the...Ch. 14 - What type of field winding is made with many turns...Ch. 14 - How is the series field connected in relation to...Ch. 14 - How is the shunt field connected in relation to...Ch. 14 - What is armature reaction?
Ch. 14 - To what is armature reaction proportional?Ch. 14 - What are eddy currents?Ch. 14 - What condition characterizes overcompounding?Ch. 14 - Prob. 14RQCh. 14 - Prob. 15RQCh. 14 - Explain the difference between cumulative- and...Ch. 14 - What three factors determine the amount of output...Ch. 14 - To what is the voltage regulation of a DC...Ch. 14 - To what is countertorque proportional?Ch. 14 - Of what is countertorque a measure?
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- Lonsider a regenerative gas turbine power plant with two stages of compression and two stages of expansion. The compressor pressure ratio of the compressor is 3. Air enters each stage of compressor at 290 K and esch stage of turbine at 1400 K. The regetierator has an effectiveness of 100%, Determine (a) The enthalpy at stage#2 in KJ/kg (b) The enthalpy at stage in KJ/kg" (c) The cathalpy at stager in KJ/kg* (d) The enthalpy at stage#10 in KJ/kg (c) The mass flow rate of air needed to develop a net power output of 50 MW *For all final answers please enter the integer part only, (ie 1234) and do not include the decimal part and the decimal point No rounding in your calculationarrow_forwardConsider a regenerative gas turbine power plant with two stages of compression and two stages of expansion. The compressor pressure ratio of the compressor is 3. Air enters each stage of compressor at 290 K and each stage of turbine at 1400 K. The regenerator has an effectiveness of 100%. Determine (a) The enthalpy at stage#2 in KJ/kg⭑ (b) The enthalpy at stage#6 in KJ/kg* (c) The enthalpy at stage#9 in KJ/kg (d) The enthalpy at stage#10 in KJ/kg (e)The mass flow rate of air needed to develop a net power output of 50 MW* *For all final answers please enter the integer part only, (ie 1234) and do not include the decimal part and the decimal point No rounding in your calculation. Compressor stage 1 Regenerator www HX ww 9 Combustor Reheat Intercooler ww Compressor stage 2 Turbine 1 combustor Turbine 2arrow_forwardDesign a proportional derivitivecontroller for a plant orsystemthat satisfies the following specifications : 1. is steady-state error is less than 2 % for a ramp input. 2.) Damping ratio (zeta) is greater than 0.7have determined the 3. Once youvalue of kp and kd, then plotthe response of the compensated(with controller) and uncompensated( without the controller, only the plantsystem using MATLAB.arrow_forward
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