Explanation Express the partial pressure of water in the saturated product mixture at the dew point. P v , prod = P sat@40°C (I) Here, saturation pressure at temperature of 40°C is P sat@40°C . Express the vapor mole fraction. y v = P v , prod P prod (II) Here, pressure of product is P prod . Express kmoles of water condensed. y v = 4 − N w N total,prod − N w (III) Here, number of moles of water is N w and number of moles of total product is N total,prod . Express the steady flow energy balance. N ˙ fuel h R = Q ˙ fuel + N ˙ fuel h P (IV) Here, enthalpy of products is h P , enthalpy of reactants is h R , rate of heat transfer of fuel is Q ˙ fuel and molar flow rate of fuel is N ˙ fuel . Express the rate of heat transfer of fuel. Q ˙ fuel = Q ˙ out η furnace (V) Here, rate of heat transfer is Q ˙ out and combustion efficiency of furnace is η furnace . Express enthalpy of products. h P = 3 h ¯ CO 2 @298 K + 4 h ¯ H 2 O@298 K + 2 h ¯ O 2 @298 K + 26.32 h ¯ N 2 @298 K + N w ( h ¯ f , H 2 O o ) liq (VI) Here, enthalpy of carbon dioxide, water, oxygen and nitrogen at temperature of 25°C is h ¯ CO 2 @298 K , h ¯ H 2 O@298 K , h ¯ O 2 @298 K and h ¯ N 2 @298 K respectively and enthalpy of formation of water is h ¯ f , H 2 O o . Express enthalpy of reactants. h R = h ¯ f o fuel@298 K + 7 h ¯ O 2 @ 298 K + 26.32 h ¯ N 2 @ 298 K (VII) Here, enthalpy of formation of fuel at temperature of 25°C is h ¯ f , fuel@25 ° C o , and enthalpy of oxygen and nitrogen at temperature of 25°C is h ¯ O 2 @298 .15 K and h ¯ N 2 @298 .15 K respectively. Express the molar flow rates of the liquid water. N ˙ w = N w N ˙ fuel (VIII) Express mass flow rate of liquid water. m ˙ w = N ˙ w M H 2 O (IX) Here, molar mass of liquid water is M H 2 O . Express volume flow rate of liquid water. ν ˙ w = v f @ 25 °C ( m ˙ w ) (X) Here, saturated liquid specific volume at temperature of 25°C is v f @ 25 °C . Conclusion: Refer Table A-4, “saturated water-temperature table”, and write saturated liquid specific volume at temperature of 25°C . v f @ 25 °C = 0.001003 m 3 / kg Refer Table A-4, “saturated water-temperature table”, and write saturation pressure at temperature of 40°C . P sat@40°C = 7.3851 kPa Refer Table A-1, “molar mass, gas constant and critical point properties”, and write the molar mass of liquid water. M H 2 O = 18 kg / kmol Express the reaction equation for 40% excess air. C 3 H 8 + 1.4 a th [ O 2 + 3. 76N 2 ] → B CO 2 + D H 2 O + E O 2 + F N 2 (XI) Here, propane is C 3 H 8 , oxygen is O 2 , nitrogen is N 2 , carbon dioxide is CO 2 , water is H 2 O and stoichiometric coefficient of air is a th . Perform the mass balance to calculate the coefficients in Equation (XI) Carbon balance: B = 3 Hydrogen balance: 2 D = 8 D = 2 Oxygen balance: 2 × 1.4 a th = 2 B + D + 2 E 0.4 a th = E (XII) Nitrogen balance: 1.4 a th × 3.76 = F (XIII) Solve Equations (XII) and (XIII) by online calculator to get, E = 2 F = 26.32 a th = 5 Substitute 3 for B , 4 for D , 5 for a th , 26.32 for F and 2 for E in Equation (XI). C 3 H 8 + 1.4 × 5 [ O 2 + 3. 76N 2 ] → 3 CO 2 + 4 H 2 O + 2 O 2 + 26.32 N 2 C 3 H 8 + 7 [ O 2 + 3. 76N 2 ] → 3 CO 2 + 4 H 2 O + 2 O 2 + 26.32 N 2 (XIV) Refer Equation (XIV) and write the number of moles of total product. N total,prod = 3 kmol + 4 kmol + 2 kmol + 26.32 kmol = 35.32 kmol Substitute 7 .3851 kPa for P sat@40°C in Equation (I). P v , prod = 7 .3851 kPa Substitute 7 .3851 kPa for P v , prod and 100 kPa for P prod in Equation (II)

9th Edition

ISBN: 9781264446889

Author: CENGEL

Publisher: MCG

See similar textbooks

Concept explainers

Entropy

In physics, entropy means the amount of disorder or the degree of randomness associated with a thermodynamic system. The system is not self-organized when the entropy of the system is high. For instance, when a system is at an elevated temperature, its m…

Videos

Question

Chapter 15.7, Problem 71P

To determine

The volume of water condensed from the product gases per day.

Expert Solution & Answer

Want to see the full answer?

Check out a sample textbook solution

See solution

Chapter 15.7, Problem 70P

Chapter 15.7, Problem 72P

Students have asked these similar questions

got wrong answers help please

A crate weighs 530 lb and is hung by three ropes attached to a steel ring at A such that the top surface is parallel to the xy plane. Point A is located at a height of h = 42 in above the top of the crate directly over the geometric center of the top surface. Use the dimensions given in the table below to determine the tension in each of the three ropes. 2013 Michael Swanbom cc00 BY NC SA ↑ Z C b B У a D Values for dimensions on the figure are given in the following table. Note the figure may not be to scale. Variable Value a 30 in b 43 in 4.5 in The tension in rope AB is 383 x lb The tension in rope AC is 156 x lb The tension in rope AD is 156 x lb

A block of mass m hangs from the end of bar AB that is 7.2 meters long and connected to the wall in the xz plane. The bar is supported at A by a ball joint such that it carries only a compressive force along its axis. The bar is supported at end B by cables BD and BC that connect to the xz plane at points C and D respectively with coordinates given in the figure. Cable BD is elastic and can be modeled as a linear spring with a spring constant k = 400 N/m and unstretched length of 6.34 meters. Determine the mass m, the compressive force in beam AB and the tension force in cable BC. Z C D (c, 0, d) (a, 0, b) A B y f m cc 10 BY NC SA 2016 Eric Davishahl x Values for dimensions on the figure are given in the following table. Note the figure may not be to scale. Variable Value a 8.1 m b 3.3 m с 2.7 m d 3.9 m e 2 m f 5.4 m The mass of the block is 68.8 The compressive force in bar AB is 364 × kg. × N. The tension in cable BC is 393 × N.

Chapter 15 Solutions

THERMODYNAMICS LLF W/ CONNECT ACCESS

Ch. 15.7 - What are the approximate chemical compositions of...Ch. 15.7 - How does the presence of N2 in air affect the...Ch. 15.7 - Prob. 3P Ch. 15.7 - Prob. 4P Ch. 15.7 - Is the airfuel ratio expressed on a mole basis...Ch. 15.7 - How does the presence of moisture in air affect...Ch. 15.7 - Prob. 7P Ch. 15.7 - Prob. 8P Ch. 15.7 - Prob. 9P Ch. 15.7 - Are complete combustion and theoretical combustion...

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.

The volume of water condensed from the product gases per day.

Solution Summary: The author analyzes the volume of water condensed from the product gases per day.

Concept explainers

Videos

The volume of water condensed from the product gases per day.

Want to see the full answer?

Chapter 15 Solutions