1、 international Journal of Heating, Ventilating, Air-Conditioning and Refrigerating Research Editor Raymond Cohen, Ph.D P.E., Professor of Mechanical Engineering and Herrick Professor of Engineering, Purdue University. U.S.A. Associate Editors Arthur E. Bergles. Ph.D., P.E., John A. Clark and Edward
2、T. Crossan Professor of Engineering, Department of Mechanical Engineering, Aeronautical Engineering and Mechanics, Rensselaer Polytechnic Institute. U.S.A. University of Oxford, United Kingdom Fire Research Laboratory, National Institute of Standards and Technology. U.S.A. Arthur L. Dexter. D.Phil.,
3、 C.Eng., University Lecturer. Department of Engineering Science, David h Didion, D.Eng., P.E., Leader, Thermal Machinery Group, Building and Raiph Qoldman, Ph.D Senior Consultant, Arthur D. Little, Inc U.S.A. Hugo Hens. Dr.Ir., Professor, Department of Civil Engineering, Laboratory of Building Physi
4、cs, Katholieke Universiteit, Belgium Ken-Ichi Simura. Dr. Eng., Professor, Department of Architecture, Waseda University and President, Society of Heating. Air-conditioning and Sanitq Engineers of Japan, Japan Horst Krusc. Dr.-Ing Professor, Institut fr Kiiltetechnlk und Angewandte Whetechnlk. Unive
5、rsitt Hannover, Germany Jean J. Lebrun, Ph.D., Professor, Laboratoire de Thermodynamique, Universit de Lige. Belgium John W. Mitchell, Ph.D P.E., Professor, Mechanical Engineering. University of Wisconsin-Madison, U.S.A. Dale E. Seborg, Ph.D Professor, Chemical Engineering, University of California,
6、 Santa Barbara, U.S.A. Policy committee Ronald J. Kessner, chair Frank M. Coda Eugene Stamper Fritz W. Steimle W. Stephen Cornstock Raymond Cohen Editorial Assistant Jenny OtletJakovljevlc Publisher Frank M. Coda Pubishng Director W. Stephen Comstock ASHRAE Editorial and Publishing Gemices Staff Rob
7、ert A. Parsons, Handbook Editor Nancy F. Thysell Adele J. Brandstrom Christina D. Tate Susan Boughadou a1995 by the American Soclety of Heating. Refrigeraung and Air-Conditionlng Engineers. Inc 1791 We Circle. Atlanta. Georgia 30329. Au rights reserved. Second class postage paid at Atlanta. Georgia.
8、 and additiod malling oftiees. HVAC primarily because, at the same time, the straw used as sleeping pallets by the prisoners began to be changed daily, thus eliminating the mites, ticks and Lice whose bites transmitted most of the lethal diseases. Concerns for Engiish workers led to advances in the
9、new field called “Industrial Hygiene.“ The Chimney Sweepers Act of 1788“ was a response to the prevalence of soot induced scrotal cancer, and Sir Humphry Davy (inventor of the miners safety lamp collaborated in a treatise describing work settings that contributed to “pthisisis“ (tuberculosis. Despit
10、e accumulation of such knowledge, there was no legislation on working condi- tions until the first in a series of “English Factory Acts“ was passed in 1833; the last Act, in 1878, established a London office to centralize factory inspection. However, much of the legislation was focused on providing
11、proper compensation for disabled workers, a trend adopted subsequently by a number of European countries, by the US in 1908 with its Federal employees compensation act, and in the laws on Workmans Compensation passed by all the States, the first in 1911 and the 48th by 1948. This approach, mandating
12、 compensation rather than change was strongly supported by John L. Lewis and his United Mine Workers Union, and probably was most effective in addressing the problems since the rising costs of workmans compensation made a stronger financial case for improving work conditions than any legislation tha
13、t might have been passed at the time. Industrial Hygiene was a well developed science by the 1960% with the American Conference of Government Industrial Hygienists (ACGIH) rec- ommending maximum long, and short. term limits for exposure to many industrial chemicals in common use. Three key pieces of
14、 legislation followed: The Metal and Non- metallic Mine Safety Act of 19%; the Federal Coal Mine Health and Safety Act of 1969; and the Occupational Safety and Health Act of 1970, which set up an Occupational Health and Safety Agency (OSHA) and empowered it to require employers to measure, record an
15、d report employee exposure to anything which might endanger their safety and health. Subsequently, a confluence of factors focused US national attention on air quality for the nonworking population. First, there were fantastic advances in the ability to detect, and measure down to lev- els of parts
16、per billion, many toxic chemicals. In my graduate training, which began in 1950, I used a kerosene smoked sheet of paper on a clockwork driven drum; this was marked by a stylus attached to a frogs muscle, to demonstrate aspects of muscle con- 173 ASHRAE TITLE*IJHVAC 1-3 95 0759650 0515538 756 1 74 H
17、VACBrR RESEARCH traction in response to electric current from an “inductorium,“ a hand wired pair of coils linked, through a vibrating contact, to a battery. Ten years later, my students used oscil- loscopes and variable power supplies. Today, small mass spectrometers are being devel- oped which, po
18、inted at a cloud some miles away, can identi its chemical components. Second, although OSHAs National Institute of Safety and Health (NIOSH) had estab- lished maximum “Ceiling Exposure Limits,“ “15 minute, Short Term Exposure Limits,“ and “8 hour, Time Weighted Average Exposure Limits“ for many of t
19、he chemicals intro- duced to industry, and thence into consumer products, it could not keep up with the more than 30,000 new chemicals being developed each year. With hindsight, it is easy to see that someone could, and probably should, have made a connection between the toxicity of lead dust and fu
20、mes (known since 400 B.C.) and that using lead in house paints or in solder for drinking water pipes was a bad idea; but who should have, and who had the authority to do anything about it? Similarly, given the known problems of asbestos miners, someone could have identified use of asbestos in wall,
21、floor and ceiling tiles, and as steam pipe insulation, as a potential problem. But who could have known that the waste oils being used to hold down the dust on unpaved roads in the 1920s and 1930s contained a chemical called dioxane: or that this would prove to be so dan- gerous a carcinogen that an
22、 Environmental Protection Agency would need billions of dollars in the 1980s and 1990s to dig up soil containing levels of dioxane above a few parts per million. to build large. specially designed sheds to store millions of tons of this soil pending development of safe, economic ways to destroy it.
23、and to pay to remediate homes and buildings contaminated by dioxane laden dust. No one dreamed that a superb, new insulation, which could be foamed in place between the studs in the walls of old and new homes, blocking any air infiltration and thus reducing the rising costs of home heating, would pr
24、oduce such serious health problems for some residents that they would have to sell their homes at a heavy discount because of the vapor in their home from this urea foam formaldehyde insulation WFFI). And it was not until the mid 1980s that a nuclear power company hired a man named Jim Watrous and f
25、ound, as he was leaving through the radiation monitors used routinely to screen all departing workers to ensure that no radioactive contamination was carried outside the plant, that he exhibited a level of radiation contamination equivalent to the carcinogenic risk from smoking thousands of packs of
26、 cigarettes a day. Investigation found that his home was built on ground which was heavily contam- inated with minerals emitting Radon. This gas was nominated by the EPA as the most serious air and water pollutant in the United States less than 10 years ago. But a study supported by the EPA in the l
27、ate 1970s clearly showed that the major problems of air quality were not so exotic. The study compared the indoor air quality in homes in three places: in a pristine, rurai area of Idaho; in a clean suburb of Virglnia near Washington DCs airports in the industrialized East; and in the heavily pollut
28、ed area of New Jersey near Newarks industries and airport. The study found that indoor air quality in homes in all three areas was equally bad; it was not outdoor air pollut- ants. but chemicals brought into the homes as cleaners, new synthetic carpet and fur- niture, mercuric wallpaper dyes, Perchl
29、orethylene from dry cleaned clothing, etc., that produced the poor IAQ. Third, the average age of death, about 40 in 1900, exceeded 60 by 1980, in part because medical advances were keeping alive infants and seniors who would have suc- cumbed to an accumulation of health problems. This lead to a gro
30、wing recognition that what was needed were “Human Lifelong Exposure Limits,“ not just for the healthy, non- working, adult population but for prenatal, young, elderly, and sick populations. Finally, the enormous increase in the costs of heating fuel as a result of OPEC actions in the 1970% induced a
31、 frenzy of effort to reduce those costs by reducing out- side air ventilation and fdtration; the classic “dilution is the solution to indoor air pollu- tion“ became non-viable. ASHRAE TITLELIJHVAC 1-3 95 W 0759650 0535539 692 VOLUME 1. NUMBER 3, JULY 1995 175 In the late 1970s a new problem of air q
32、uality appeared. There was an outbreak of respiratory disease, with a number of fatalities, in guests at Philadelphias Bellevue- Stratton Hotel, many of whom were attending an American Legion convention. In response to questions as to the source of the Legionella bacteria eventually identified as th
33、e agent. and the role of the mist from an air conditioning cooling tower, ASHRAE established an ad-hoc Presidential Committee on kgionnaires Disease in 1980; as one of the few physiologists belonging to the Society, I was appointed to it. Experts from other societies were invited to join this commit
34、tee. Some opted to join ASHRAE and, a few years later, were appointed to ASHRAEs Special Project Committee for the regular, five year revision of Standard 62 on ventilation. Recommended ventilation levels, set at a 35 cfm level in the 1920s and reduced to less than half that under the economics of e
35、nergy costs in the 1970% were returned toward the earlier levels as a result of IAQ concerns, with higher requirements in areas where smoking was allowed. The revision committee also attempted to introduce stricter limits for some respirable particle levels and volatile organic compounds and ran int
36、o a legal barrage from aggrieved parties. In 1984, the president of ASHRAE asked me, as one of ASHRAEs directors, to Chair an ad-hoc Committee on Environmental Health Issues to investigate whether ASHRAE needed to become more involved in such issues. This committee came back with an unusual recommen
37、dation: not only did ASHM need to establish a Committee on Environmental Health and Indoor Air Quality, but this committee needed to bring in added expertise on these issues. The ad-hoc committee also noted that many countries (especially in Scandinavia where the severe winters and lack of oil had,
38、for centuries, resulted in construction of tighter buildings) were well ahead of the US. In 1700 AD, physicians were instructed by Ramazzini, in his “De Morbis Artificum“ to ask their patients “of what trade are you?“ About the mid 1900s. physicians began to ask about alcohol and cigarette consumpti
39、on. In his 1950 opus “Stress,“ Hans Selye defined a “General Adaptation Syndrome,“ a systemic response of the body to resist any stressor. If overwhelmed by cumulative challenges, the exhaustion of these defense mechanisms is manifest by whatever genetic susceptibility the individual might have; i.e
40、 heart, lung, kidney disease, etc. Today, although still not totally accepted by the medical profession, as a result of increasing exposure to a wide range of chemicals at work and at home, there appears to be a growing population of chemically hypersensi- tive individuals. Growing awareness of the
41、stressful effects of life long exposure to such chemicals, to the noise we are assaulted by in our daily lives and to the, stili ques- tioned, mortality effects of living near nuclear power plants and/or high voltage lines (or even the use of electric heated blankets) may soon lead physicians to ask
42、 about such exposures when taking any new patients history. Over the last 15 years our knowledge of environmental health and air quality issues has increased dramatically. Cigarette smoking is increasingly being limited in public areas, although there are still questions as to whether it is the toxi
43、city of tobacco tar combustion products from smoking, or the extension of clearance times for inspired gases and particulates (from a few days to as many months as a result of the cilia (hair like, microscopic structures) on the surface of the cells lining the respiratory tract being so overworked a
44、s to become unable to sweep the intrusions out of the lungs. The indoor level of carbon dioxide, the normal output of body metabolism, is being used as a marker of ventilation. Some new construction, and most new furnishings and fabrics, are specfically designed to eliminate possible sources of indo
45、or air pollutants. The very restrictive Russian and far more liberal US standards for permissible exposures to elec- tro-magnetic radiation are being examined to see which is right. Concerns for destruc- tion of the ozone layer, and its effects on extra-terrestrial radiation reaching the earth, are
46、legislating changes in refrigerants. The roles of noise, poor lighting, “life stress events“ ranging from getting a traffic ticket to losing a spouse. and other stressors are all being examined for their impacts on health. Not all of these fali into the domain of ASHRAE TITLEtIJHVAC 1-3 95 0759b50 0
47、515540 304 176 HVAC physical or empirical models. The chief disadvantage of this approach is the time and effort required both to develop a sufficiently accurate process model and to subsequently update it as conditions change. A number of WAC applications of this general residual-monitoring approac
48、h have been reported. For example, residual generation using a dynamic physical model and Paul S. Fado is a manufacturing engineer at the Etec Corporation, Hayward, CA. Dale E. Sebog is Professor of Chemical Engineering at the University of California, Santa Barbara. 177 178 HVAC and four input vari
49、ables: u, the normalized valve position; T, the inlet air temperature; q. the mass flow rate of the air: and Twi, the inlet water temperature. The single manipulated input, u, is expressed as a normalized variable between zero and one. The other three input variables are considered to be disturbances. Process Yodel The static and dynamic behavior of this heating coil subsystem has been modeled by Tdtli et al. (1982) based on mass and energy balances. This model has also been used in a companion study (Fasolo and Seborg 1
