Explanation Express the combustion equation of hydrogen with 20% excess air. H 2 + 1.2 a th ( O 2 + 3.76 N 2 ) → x H 2 O + 0.2 a th O 2 + 4.512 a th N 2 (I) Here, hydrogen is H 2 , stoichiometric coefficient of air is a th , oxygen is O 2 , nitrogen is N 2 , carbon dioxide is CO 2 and water is H 2 O . Equate components to calculate the coefficients in Equation (I) Hydrogen balance: 2 = 2 x x = 1 Oxygen balance: 2.4 a th = x + 0.4 a th 2 a th = 1 a th = 0.5 Substitute 1 for x and 0.5 for a th in Equation (I). H 2 + 1.2 × 0.5 ( O 2 + 3.76 N 2 ) → 1 H 2 O + 0.2 × 0.5 O 2 + 4.512 × 0.5 N 2 H 2 + 0.6 ( O 2 + 3.76 N 2 ) → H 2 O + 0.1 O 2 + 2.256 N 2 (II) As the combustion process is a steady flow process, thus heat lost is equal to the heat gained. H prod = H react ∑ N P ( h ¯ f o + h ¯ exit − h ¯ 537 R ) P = ∑ N R ( h ¯ f o − h ¯ 280 − h ¯ 537 R ) R (III) Here, number of moles of products is N P , number of moles of reactants is N R , enthalpy of formation is h ¯ f , enthalpy is h ¯ , enthalpy of products and reactants is H prod and H react Express the total number of moles. N total = N H 2 O + N O 2 + N N 2 (IV) Here, number of moles of water, oxygen and nitrogen is N H 2 O , N O 2 and N N 2 respectively. Conclusion: Refer Equation (II), and write the number of moles of products. N P , H 2 O = 1 lbmol N P , O 2 = 0.1 lbmol N P , O 2 = 2.256 lbmol Here, number of moles of product hydrogen, oxygen and nitrogen is N P , H 2 O , N P , O 2 and N P , N 2 respectively. Refer Equation (II), and write the number of moles of reactant. N R , H 2 = 1 lbmol Here, number of moles of reactant hydrogen is N R , H 2 . Refer Appendix Table A-18E, A-19E, A-22E and A-26E and write the property table for products and reactants as in Table (1). Substance h f o ¯ ( Btu / lbmol ) h ¯ 500 R ( Btu / lbmol ) h ¯ 537 R ( Btu / lbmol ) H 2 0 3386.1 3640.3 O 2 0 3466.2 3725.1 N 2 0 3472.2 3729.5 H 2 O ( g ) − 104 , 040 3962 4258 Substitute the values form Table (I) into Equation (III) to get, [ 1 ( − 104 , 040 + h H 2 O − 4258 ) + 1 ( 0 + h O 2 − 3725.1 ) + 2.256 ( 0 + h N 2 − 3729

9th Edition

ISBN: 8220106796979

Author: CENGEL

Publisher: YUZU

See similar textbooks

Videos

Question

Chapter 15.7, Problem 75P

To determine

The exit temperature of the product gases.

Expert Solution & Answer

Want to see the full answer?

Check out a sample textbook solution

See solution

Chapter 15.7, Problem 74P

Chapter 15.7, Problem 76P

Students have asked these similar questions

-6- 8 من 8 Mechanical vibration HW-prob-1 lecture 8 By: Lecturer Mohammed O. attea The 8-lb body is released from rest a distance xo to the right of the equilibrium position. Determine the displacement x as a function of time t, where t = 0 is the time of release. c=2.5 lb-sec/ft wwwww k-3 lb/in. 8 lb Prob. -2 Find the value of (c) if the system is critically damping. Prob-3 Find Meq and Ceq at point B, Drive eq. of motion for the system below. Ш H -7~ + 目 T T & T тт +

Q For the following plan of building foundation, Determine immediate settlement at points (A) and (B) knowing that: E,-25MPa, u=0.3, Depth of foundation (D) =1m, Depth of layer below base level of foundation (H)=10m. 3m 2m 100kPa A 2m 150kPa 5m 200kPa B

W PE 2 43 R² 80 + 10 + kr³ Ø8=0 +0 R²+J+ kr200 R² + J-) + k r² = 0 kr20 kr20 8+ W₁ = = 0 R²+1) R²+J+) 4 lec 8.pdf Mechanical vibration lecture 6 By: Lecturer Mohammed C. Attea HW1 (Energy method) Find equation of motion and natural frequency for the system shown in fig. by energy method. m. Jo 000 HW2// For the system Fig below find 1-F.B.D 2Eq.of motion 8 wn 4-0 (1) -5- m

Chapter 15 Solutions

EBK THERMODYNAMICS: AN ENGINEERING APPR

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 exit temperature of the product gases.

Solution Summary: The author explains how to express the combustion equation of hydrogen with 20% excess air.

Videos

The exit temperature of the product gases.

Want to see the full answer?

Chapter 15 Solutions