1、FUNDAMENTALS OF GAS APPLIANCES THIRD EDITION Fundamentals of Gas Appliances Combined Manual and Workbook ORIGINALLY PREPARED BY Gas Appliance Manufacturers Association For AMERICAN GAS ASSOCIATION 400 North Capitol Street NW Washington, DC 20001 Catalog No. XH0501 Copyright 2005 By American Gas Asso
2、ciation First Printing August 2005 Printed in United States of America i Catalog No. XH0501 Third Edition, First Printing Copyright 2005, Revised March 2005 Registered by American Gas Association Printed in the United States of America Cover photos furnished by North American Technician Excellence (
3、NATE), Vent-Free Gas Products Alliance and Gas Appliance Manufacturers Association (GAMA). ii iii FOREWORD The original manual was prepared under the direction of the American Gas Association and Gas Appliance Manufacturers Association, Inc. Joint Committee for Customer Service, and written by J. Fr
4、ed Parr, Manager of Engineering Services, American Gas Association Laboratories, Cleveland, Ohio. The 2005 edition was edited and prepared by Mary Smith Carson, Consultant, Roger Carson Enterprises, Inc. (RCEI). The editors wish to thank James W. Freeman, Vent-Free Gas Products Alliance, Rheem Water
5、 Heaters, Whirlpool Corporation, Monessen Hearth Systems, ECS, Rasmussen Iron Works, Cozy Heating, Copreci S. Coop., David Sutula and David Bixby of GAMA for their assistance. The purpose of the manual is to provide a text for self-study. It is intended to become a useful tool to vocational-technica
6、l schools, appliance service and repairpersons, and utility customer service programs. The text has been prepared so that only a moderate knowledge of mathematics and science is required for understanding. Other texts in this series cover the following fundamental subject areas: Venting and Ventilat
7、ion Electricity Gas Controls Gas Combustion Customer Service A glossary is provided at the rear of the book. The text material will be more meaningful to the students if they familiarize themselves with these terms. Words that are defined in the glossary are noted in bold face type the first time th
8、ey appear in the text. For specific installation instructions always refer to the manufacturers instructions and or the local codes required by the authority having jurisdiction. This book is meant to be used only as a guide in explaining the fundamentals of the specific gas appliances listed within
9、 it. For more detailed information concerning a specific make or model of a gas appliance always check with the manufacturer. Most manufacturers offer installation and service manuals on their specific internet website. RCEI wishes to thank all the members of the American Gas Association Utility and
10、 Customer Field Ser-vices Committee for their review and editorial comments. DISCLAIMER The AGA (together with its members) disclaims liability for any personal injury, property or other damages of any nature whatsoever, whether special, indirect, consequential or compensatory, directly or indirectl
11、y resulting form the publication, use of, or reliance on this document or whether based on information contained in or omitted from this document. All warranties, express or implied, are disclaimed, including without limitation, any and all warranties concerning the accuracy of the information, its
12、fitness or appropriateness for a particular purpose or use, its merchantability and its non-infringement of any third partys intellectual property rights. AGA (together with its members) expressly disclaims any and all responsibilities for the accuracy or completeness of the information and makes no
13、 representations or warranties regarding the informations compliance with any applicable statute, rule or regulation. In issuing and making this document available, the AGA (together with its members) is not undertaking to render professional or other services for or on behalf of any person or entit
14、y. Nor is the AGA undertaking to perform any duty owed by any person or entity to someone else. Anyone using this document is doing so at the users own discretion and at its own risk. The user should seek the advice of a competent professional in determining the exercise of reasonable care in any gi
15、ven circumstances. This manual is not designed to provide installation, repair or maintenance instructions. Equipment should be installed, repaired or maintained in compliance with manufacturers instructions, applicable building codes and regulations and national standards. This manual is not intend
16、ed to take the place of those documents. iv TABLE OF CONTENTS I. INTRODUCTION . 1 Using the Heat. 1 Use of Gas . 1 Different Kinds of Fuels . 2 Manufactured Gas 2 Natural Gas. 2 LP-Gas 2 Appliance Standards . 2 Chapter Review. 4 II. COOKING APPLIANCES 6 Domestic Cooking 6 Types of Range Construction
17、 6 General Construction of Ranges 8 Ovens for example, baking ovens and commercial water heaters and dishwashers. About 40 percent of the gas produced in the United States is used in industry. Large quantities of gas are used in making steels, glass, chemi-cals, paper and in food processing. The gas
18、 com-bustion equipment used in these industrial proc-esses differs substantially from that used in do-mestic applications, but the idea is the sameutilization of the heat energy produced.1 2 Fundamentals of Gas Appliances DIFFERENT KINDS OF FUELS Manufactured Gas Long ago in Europe fuel gas was manu
19、factured to be used for lighting. In the United States manufactured gas* was also produced and widely distributed especially in the northeastern states. This manufactured gas is most often pro-duced by passing steam over heated coal. It con-tains hydrogen and carbon monoxide as the heat-producing co
20、mbustible gases. This gas burns with very different characteristics than natural gas, which is mostly methane. Very little manu-factured gas is now used, having been replaced by natural gas supplies. Synthetic natural gas (SNG) can be made from coal or petroleum liq-uids to augment the current natur
21、al gas supply. Although this gas is “manufactured” it differs from the earlier form of manufactured gas in that it will be mostly methane and be nearly identical to natural gas in composition and burning charac-teristics. There are other manufactured fuel gases such as coke oven gas and blast furnac
22、e gas but these are not distributed to domestic customers except rarely as small additions to natural gas supplies. Natural Gas Natural gas is used as the main fuel gas today. It is called natural gas because the gas is found in the earth. It occurs as a mixture of hydrocarbon and nonhydrocarbon gas
23、es often in association with petroleum. The natural gas of commerce, supplied to fuel gas markets, is usually 80 to 95 percent methane; the principal constituent of all natural gases. Most of the remainder is nitrogen with some natural gases containing heavier hy-drocarbons or carbon dioxide. Heatin
24、g values of natural gases range from about 900 to 1200 Btu per cubic foot. LP-Gas Liquefied petroleum (LP) gas is a petroleum product obtained from both gas and oil wells. The “wet” gas from these wells is a mixture of methane, ethane, propane, butane and heavier hydrocarbons. This gas is refined in
25、 a natural gasoline plant where the various components are separated. The methane and ethane extracted by this process are distributed as natural gas; the propane and butane are used as liquefied fuel gases; while the heavier hydrocarbons are used in the production of gasoline. Additional pro-pane a
26、nd butane are obtained as byproducts of refinery operations. Commercially distributed LP gases may be considered mixtures of pro-pane and butane. Propane gas mixtures can eas-ily be liquefied and thereby reduced in volume by moderate pressure, so they are shipped and stored as liquids until used. LP
27、 gas heating val-ues range from about 2500 Btu per cubic foot of gas to somewhat over 3000 Btu per cubic foot of gas depending on the relative amounts of propane and butane. Gas appliances operate on both types of gas but must be shipped as a natu-ral gas appliance or a propane appliance. APPLIANCE
28、STANDARDS In 1903, the Philadelphia Gas Works Company drew up specifications for gas ranges to enable manufacturers to build their ranges to meet cer-tain specific requirements. These specifications were prepared after several years of observation by the gas company and expressed its view of what wa
29、s desirable construction from the stand-point of the customer and the utility in terms of safety and performance. Work was continued on gas appliances by individual gas utilities and some cooperative efforts until the American Gas Association (AGA) was formed in 1918. AGA then assumed the task of pr
30、eparing appliance standards. In order to demonstrate that appliance models would conform to the standards, in 1925 the American Gas Association established the Test-ing Laboratories. In 1930 the American Gas As-sociation Approval Requirements Committee be-came a Section Committee (Z21) of the Ameri-
31、can Standards Association. The Z21 Committee of the American Nationals Standards Institute * Words that appear in text in bold italics are defined in the glossary starting on page 80. Introduction 3 The FTC label for furnace and boilers shows the Annual Fuel Utilization Efficiency (AFUE); for water
32、heaters the energy factor (EF) is shown. AFUE values for most furnaces and boilers can be found in the GAMA “Consumers Directory of Certified Efficiency Ratings for Heating and Water Heating Equipment. (http:/www.gamanet.org/gama/inforesources.nsf?OpenDatabase) The GAMA Furnace and Hy-dronics Instit
33、ute Divisions sponsor the certifica-tion program for residential gas and oil central furnaces and boilers. (ANSI) today supervises the making of gas appliance standards with subcommittees conducting assignments for each appliance type. ANSI is the descendent of the American Standards Association. Th
34、ere are over sixty ANSI gas appliance standards, each being constantly revised and updated by a consensus subcommittee made up of representatives from gas utilities, appliance manufacturers, consultants, government and other interested parties. Similarly, the ANSI Z83 Committee is responsible for co
35、mmercial gas appliance and accessory standards. Natural gas is used in a multitude of applications in industry such as heat-treating furnaces, kilns, atmosphere furnaces, drying ovens and process steam generators. Since most of this equipment is custom designed and built, or service requires specifi
36、c training, these types of equipment are not covered in this manual. This manual does describe most kinds of domestic and commercial gas-using devices encountered by the utility or private company general gas service persons. Only cursory attention is given to controls and control systems since they
37、 are discussed in more detail in Fundamental of Gas Controls, another manual in this series. Also since this manual is intended to cover only general appliance operations and principles, trouble-shooting methods have not been included. Troubleshooting and repair are discussed in other manuals in thi
38、s series and in “Gas Heating Controls Service Manual” and “Gas Appliance Service Manual.”* In cases of specific appliances, information can be generally obtained from the manufacturers. Prototype models of gas appliances are tested for compliance to the appropriate national standards at CSA. If desi
39、gns are accepted as complying, the manufacturer is authorized to display the Certification Seal on production models. The seal is granted for each appliance design. When standards are revised, the appliance must be retested at a nationally recognized laboratory. The seal does not indicate quality or
40、 cost of an appliance but only that the design meets or surpasses a national standard for safety, performance and construction. The Energy Policy and Conservation Act of 1975 required the Federal Trade Commission (FTC) to issue labeling rules for disclosure of energy and cost of operation informatio
41、n of major home appliances. The labels give consumers the estimated cost or energy efficiency of competing products. This information will enable consumers to: (1) compare the relative costs of competing appliances and (2) consider both the purchase price and long term energy cost of the appliance.
42、Consumers are now seeing appliances that are marked with an Energy Star logo. This logo represents that the appliance meets strict energy efficient guidelines set by the Environmental Protection Agency (EPA) and the U.S. Department of Energy (DOE). * References and their sources are listed on page 7
43、8. 4 Fundamentals of Gas Appliances I. QUESTIONS INTRODUCTION ANSWERS Sample question 1. Forty percent of the gas produced in the United States is used by 2. Industry. The answer to this question can be found on page 1. (1) Methane Pressure Forty percent 2. The first gas appliances were gas 1. _ use
44、d over 150 years ago for 2._ _. (1)Lights Street lighting Industry 3. Natural gas is composed mainly of 1. _. (2)H | HCH | H 4. Commercially distributed liquefied petroleum (LP) gas can easily be liquefied and reduced in volume for shipping and storage by applying moderate 1. _. (2)H H H | | | HCCCH
45、 | | | H H H PROPANE C3H8Introduction 5 I. QUESTIONS INTRODUCTION CONT. ANSWERS 5. The American Gas Association (AGA) was formed in 1918 and un-dertook the task of preparing appliance standards for durable 1. _, as well as, minimum requirements for 2. _ and 3. _. (2)Construction Annual Fuel Utili-za
46、tion Efficiency National Standard 6. The Certification Seal does not indicate quality or cost of an appli-ance but only that the design meets or surpasses the 1. _ _ for safety, performance and construction. (3)Safety Performance 7. The AFUE rating of a furnace or boiler indicates the 1. _ _ _ _. (3
47、)II Cooking Appliances DOMESTIC COOKING The first gas appliance to be sold in the United States on a wide scale was the domestic gas range. The design of the gas range has pro-gressed from a counter top, match-lit unit to the sophisticated range of today with automatic igni-tion, self-cleaning oven
48、and timed cooking fea-tures. Types of Range Construction The most popular range style is called “free- standing,” Figure 1. Free-standing ranges are self-contained and self-supporting. They offer the obvious advantage over built-in types that may be moved, by a qualified professional, from house to
49、house with no remodeling or kitchen modification required for installation. This style may be of very simple construction or have all the most deluxe features obtainable on a gas range. It may have a single oven and low broiler; an oven and broiler in the same compartment; double ovens with two low broilers; a broiler compartment immediately
