ENVIRONMENTAL AND FUNCTIONAL ENGINEERING OF AGRICULTURAL BUILDINGS

Transcription

1 ENVIRONMENTAL AND FUNCTIONAL ENGINEERING OF AGRICULTURAL BUILDINGS

2 ENVIRONMENTAL AND FUNCTIONAL ENGINEERING OF AGRICULTURAL BUILDINGS H. J. BARRE The Ohio State University Columbus, Ohio L. L. SAMMET University of California Berkeley, California G. L. NELSON The Ohio State University Columbus, Ohio An ovi Book Published by Van Nostrand Reinhold Company New York

3 An AVI Book (A VI is an imprint of Van Nostrand Reinhold Company Inc.) Copyright 1988 by Van Nostrand Reinhold Company Inc. Softcover reprint of the hardcover 1st edition 1988 Library of Congress Catalog Card Number ISBN-13: All rights reserved. No part of this work covered by the copyright hereon may be reproduced or used in any form or by any means-graphic, electronic, or mechanical, including photocopying, recording, taping, or information storage and retrieval systems-without written permission of the publisher. Van Nostrand Reinhold Company Inc. 115 Fifth Avenue New York, New York Van Nostrand Reinhold Company Limited Molly Millars Lane Wokingham, Berkshire RGll 2PY, England Van Nostrand Reinhold 480 La Trobe Street Melbourne, Victoria 3000, Australia Macmillan of Canada Division of Canada Publishing Corporation 164 Commander Boulevard Agincourt, Ontario MIS 3C7, Canada Library of Congress Cataloging-in-Publication Data Barre, H. 1. (Henry J.), Environmental and functional engineering of agricultural buildings. "An AVI book." Includes bibliographies and index. 1. Farm buildings-environmental engineering. I. Sammet, L. L. (Loy Luther) II. Nelson, G. L. (Gordon Leon), III. Title. TH6057.F35B ISBN-13: e-isbn-13: DOl: /

4 Contents PREFACE / xi 1 HEAT TRANSFER The Nature of Heat-Units of Measure / 1 Heat Transfer / 3 Conduction / 4 Radiation / 12 Convection / 19 Symbols Used in Chapter 1 / 23 Problems / 24 Bibliography / 26 2 HEAT FLOW THROUGH WALLS Wall Construction-Heat Conductance / 27 Heat Transmission Coefficients for Walls / 33 Symbols Used in Chapter 2 / 39 Problems / 39 Bibliography / 40 v

5 vi CONTENTS 3 PSYCHROMETRICS Air-Water Vapor Mixtures / 41 Symbols Used in Chapter 3 / 57 Problems / 58 Bibliography / 59 4 MOISTURE CONDENSATION IN WALLS Temperature Gradient / 60 Condensation on Wall Surfaces / 62 Condensation within Walls / 64 Laboratory and Field Observations / 72 Symbols Used in Chapter 4 / 75 Problems / 76 Bibliography / 76 5 ESTIMATING HEATING AND COOLING LOADS Introduction / 78 Heat Flow through Enclosures / 79 Design Temperatures / 79 Solar Radiation / 81 Total Solar Radiation it / 84 Building Surface Characteristics (exl fa) / 87 Heat Sources in Buildings / 89 Seasonal Heat Load / 91 Symbols Used in Chapter 5 / 94 Problems / 94 Bibliography / 96 6 REACTIONS OF ANIMALS TO THERMAL AND OTHER ENVIRONMENTAL FACTORS (by Robert E. Stewart) Homeostasis / 98 Environmental Parameters / 102 Productive and Physiological Parameters / 103 Heat Production and Dissipation / 103

6 CONTENTS vii Some Specific Animal Reactions I 109 Symbols Used in Chapter 6 I 122 Bibliography I PRINCIPLES OF CROP AND FOOD PRESERVATION AND STORAGE Introduction I 124 Preservation Methods I 134 Problems I 139 Bibliography I VENTILATION Estimating Air Flow Rate / 141 Heat Balances in Ventilation / 144 Ventilation Systems / 153 Natural Ventilation / 159 Forced Ventilation / 161 Symbols Used in Chapter 8 / 165 Problems / 167 Bibliography / DRYING AND COOLING STORED CROPS Introduction / 170 Moisture Content / 171 The Drying Process / 173 Theoretical Analysis / 180 Cooling Stored Products / 191 Symbols Used in Chapter 9 / 194 Problems / 195 Bibliography / LIVESTOCK WASTE MANAGEMENT Introduction / 198 Waste Generation by Livestock / 200 Collecting Livestock Wastes / 206

7 viii CONTENTS Storage / 209 Gases and Odors from Wastes / 212 Treatment / 214 Symbols Used in Chapter 10 / 217 Problems / 218 Bibliography / DAIRY HOUSING Introduction / 220 Environment / 221 Sanitation / 225 Space Requirements / 226 Arrangement of Space / 229 Storage / 237 Ventilation / 242 Problems / 246 Bibliography / SWINE HOUSING Basic Considerations / 249 Building Systems / 253 Ventilation / 256 Manure Handling / 262 Bibliography / STORAGE OF FRUITS AND VEGETABLES Introduction / 264 Ventilated Storage / 267 Refrigerated Storage / 276 Functional Requirements of Apple Storage / 276 Rate of Cooling / 278 Symbols Used in Chapter 13 / 290 Problems / 290 Bibliography / 291

8 CONTENTS ix 14 GRAIN STORAGE Introduction / 293 Conditioning Moist Grains in Storage / 298 Aerating Stored Grain / 304 Grain Storage and Handling Systems / 309 Symbols Used in Chapter 14 / 312 Problems / 312 Bibliography / 313 APPENDIXES / 315 INDEX / 339

9 Preface This book has been written as a textbook for students seeking a professional degree in agricultural engineering. The authors believe that for students with this objective the course of study should be primarily analytical, rather than descriptive, and that the analytical approach should apply not only to ideas but also to quantitative procedures and computations. We recognize that sound analysis, particularly in applied fields, is based on the understanding of theoretical principles and on knowledge of many practical considerations. We have tried to maintain a good balance between the preparation of theory and practice, but we favor emphasis of theoretical considerations on the basis that they usually are not mastered except in an organized course of study, whereas practical knowledge is more easily assimilated. To present both theory and practice makes heavy demands on class time and textbook space. For this reason it has been possible to treat in detail only a few typical environmental systems for livestock housing and storing agricultural products as a means of illustrating methods of analysis and the application of principles. It is presumed, however, that such study will prepare the student for work with other types of structures. The book was prepared on the assumption that most of the professional curricula in agricultural engineering require all students to take one course in environmental engineering of farm structures, although only a small proportion of students later become specialists in this field. This book therefore may provide the basis of a five-hour course on the quarter system or a three-hour course on the semester system. The chapters in the book relate to topics on environmental and functional requirements, knowledge of which should prove valuable to agricultural engineers in all fields of specialization. Structural analysis and xi

10 xii PREFACE design of farm structures could be treated in a second course for students electing to specialize in this area. This book is primarily one on engineering the environment and its control in agricultural engineering educational programs. Prerequisite courses are presumed to include engineering mechanics, thermodynamics, and fluid mechanics. Heat transfer would be helpful but not essential. The authors have drawn material from many sources. Every effort has been made to acknowledge these contributions. We wish most of all to acknowledge the contribution of the late Mr. Harold E. Pinches, who was responsible for the conception of this book as one in a series of textbooks in agricultural engineering and whose effort in arranging its sponsorship has made the writing and publication possible. The authors are grateful for the contribution of Dr. M. Y. Hamdy, Professor of Agricultural Engineering, Ohio State University, in developing the theory and solutions for the analysis of drying and cooling grain. We also wish to acknowledge the effort by Mr. Edgar L. Barger, Retiree of the Massey-Ferguson Foundation, in arranging for sponsorship and support of this book.