1、 International Journal of Heating, Ventilating, Air-conditioning and Refrigerating Research Editor John W. Mitchell, Ph.D., P.E. Professor of Mechanical Engineering University of Wisconsin-Madison, USA Associate Editors James E. Braun, Ph.D., P.E., Associate Professor, Ray W. Herrick Laboratories, A
2、lberto Cavallini, Ph.D., Professor, Dipartmento di Fisicia Tecnica, University of Padova, Italy Arthur L. Dexter, D.Phil., C.Eng., Reader in Engineering Science, Department of Leon R. Glicksman, Ph.D., Professor, Departments of Architecture and Ralph Goldman, Ph.D., Chief Scientist, Comfort Technolo
3、gy, Inc., Framingham, Massachusetts, USA Anthony M. Jacobi, Ph.D., Associate Professor and Associate Director ACRC, Department of Mechanical and Industrial Engineering, University of Illinois, Urbana-Champaign, USA Jean J. Lebrun, Ph.D., Professor, Laboratoire de Thermodynamique, Universit de Lige,
4、Belgium Reinhard Radermacher, Ph.D., Professor and Director, Center for Environmental Energy Keith E. Starner, P.E., Engineering Consultant, York, Pennsylvania Jean-Christophe Visier, Ph.D., Head, Centre Scientifique et Technique du Btiment Energy Management Automatic Controller Division, Marne La V
5、alle, France School of Mechanical Engineering, Purdue University, West Lafayette, Indiana, USA Engineering Science, University of Oxford, United Kingdom Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, USA Engineering, Department of Mechanical Engineering, University of Mary
6、land, College Park, USA Policy Committee Lee W. Burgett, chair Jack B. Chaddock Ken-Ichi Kirnura John W. Mitchell Frank M. Coda W. Stephen Comstock Editorial Assistant Publisher ASHRAE Staff Jennifer A. Haukohl W. Stephen Comstock Mark S. Owen, Handbook Editor Jayne Jackson, Publishing Services Nanc
7、y F. Thysell, Typographer 02001 by the American Society of Heating, Refrigerating and Air-Con- ditioning Engineers, Inc., 1791 Tullie Circle, Atlanta, Georgia 30329. All rights reserved. Periodicals postage paid at Atlanta, Georgia, and additional mailing offices. HVAC nor may any part of this book
8、be reproduced, stored in a retrieval system, or transmitted in any form or by any means+lectronic, photocopying, recording, or other-without permission in writing tom ASHRAE. Abstracts-Abstractid and indexed by ASHRAE Abstract Center; Ei (Engineering Information, Inc.) Ei Compendex and Engineering I
9、ndex; IS1 (Institute for Scientific Information) Web Science and Research Alert; and BSRIA (Building Services Research ., - To, = O and increasing infiltration with increasing ITi, - Toutl, and Figure 5 shows increasing infiltration with increasing wind speed. Particle deposition rates in the test h
10、ouse were determined both for use in the CONTAM model and for the analysis of filtration efficiencies. The analysis of deposition rates was very VOLUME 7. NUMBER 3. JULY 2001 229 on o a -5 O 5 IO I5 Tm - Toia (“Cl Figure 4. Measured Hourly Infiltration Rates (Wind Speed - 5 1.OE+6 e 1.OEt5 HVAC 1000
11、000 r 500000 O c) 0.7 - 1.0 P 1 600000 I - 500000 E 5 400000 8 300000 e ; 200000 2 100000 O I d) 1.0 - 5.0 90000 ,. 80000 2 70000 e 60000 50000 8 40000 30000 10000 O 5 20000 Figure 13a-d. Comparison of Measured and Simulated Particle Counts with Decay Test MAClb Filtration Efficiency VOLUME 7, NUMBE
12、R 3, JULY 2001 24 1 turned on at the start of the test which resulted in the initial sharp decline seen in Figure 14. The particle source was on from 12:OO P.M. to 4:OO P.M. The percent difference between measured and simulated 24 h average particle concentrations was 11.7% for 0.3 pm to 0.5 p parti
13、cles, 12.6% for 0.5 p to 0.7 pm, -15.2% for 0.7 p to 1.0 p, and -27.2% for 1.0 p to 5.0 pm. The percent differences at any point in time ranged from -82% to 142% but fluctuated much more than for MAClb. This larger fluctuation was likely due to the smaller absolute particle concentrations in the bui
14、lding as a result of the highly effective air cleaner. EACl was also modeled for the same case using the total removal efficiencies determined by decay tests (values in Table 5) in combination with the system-off deposition rates (values in Table 2). The simulated indoor particle concentrations usin
15、g this method are presented in Fig- ures 15a through 15d. The percent difference between measured and simulated 24 h average par- ticle concentrations was 16.0% for 0.3 pm to 0.5 pm particles, 16.8% for 0.5 p to 0.7 pm, -9.7% for 0.7 pm to 1.0 p, and -23.4% for 1.0 p to 5.0 pm. The percent differenc
16、es at any point in time ranged just as widely as the previous method from -87% to 153%. Similar to the MAC1b predictions, the CONTAM predictions with this method were somewhat closer to the measurements for the two larger size ranges but somewhat further from the measurements for the two smaller siz
17、e ranges. The statistical measures from ASTM D5 157 were calculated for the predicted particle con- centrations for the cases presented in Figures 12 to 15 above. All of the model predictions met the criteria given above for adequate model performance for all the statistical measures with 9000000 80
18、00000 7000000 -2 6nooono - 2 5000000 4000000 3000000 2 a 2000000 1000000 O - b) 0.5 - 0.7 p 1400000 I 1200000 - -E 1000000 . 1 ; 800000 : 6onooo = 4nonno P 2noooo o - O IS d- Measured A CONTAM 200000 I80000 160000 140000 5 120000 100000 v 0 80000 .y 60000 2 40000 20000 O - d) 1.0 - 5.0 P Soo00 45000
19、 - 40000 E 35000 30000 2 25000 20000 .; 15000 5000 O - 2 10000 Figure 14a-d. Comparison of Measured and Simulated Particle Counts with Direct EACl Filtration Efficiency 242 HVAC 60000 2 40000 20000 O I c) 0.7 -1.0 p I b) 0.5 - 0.7 p 1200000 . I “E 000000 800000 u 600000 Z 400000 200000 O . 5 - 2 Fig
20、ure 15a-d. Comparison of Measured and Simulated Particle Counts with Decay Test EAC1 Filtration Efficiency very few exceptions. For example, the correlation coefficient for all cases was greater than 0.94 for all cases and was 0.98 to 0.99 for all cases except the two smallest size particles with th
21、e electronic air cleaner operating. Similarly, the NMSE was less than 0.2 for all cases and was less than 0.1 for many cases. The bias measures fared nearly as well with the model predictions meeting the criteria for all cases except for the predictions for the largest size particles which were slig
22、htly outside the adequate criteria for FB. DISCUSSION The primary objective of this effort was to evaluate the capability of the multizone IAQ model CONTAM to simulate the impact of particle air cleaners in a real building subject to real ambient conditions. As shown in Figures 12 through 15, it is
23、possible to adequately predict the air cleaner performance, at least for a single zone building without occupants present. Future work is underway to extend the project to include measurements and predictions of particle air cleaners in an occupied home. One important limitation of this study was th
24、at simulations and predictions were made for the HVAC system operating at steady-state condition. This was nec- essary as the current CONTAM model is not capable of modeling the cycling of the system to meet a thermal load. A thermal model is currently being added to the model. Although both the dec
25、ay and direct methods resulted in good predictive accuracy, the decay method was found to be somewhat more accurate than the direct method. This is because it yielded a filtration efficiency for the HVAC system and air cleaner as an installed unit. Thus, factors such as leakage around a poor fitting
26、 air cleaner and deposition in the ductwork is VOLUME 7, NUMBER 3, JULY 2001 243 accounted for in the measured efficiencies. However, for typical design applications, an “installed” efficiency would not be available and the manufacturer test data that might be similar to the direct method efficienci
27、es would need to be used. These efficiencies would then need to be combined with appropriate deposition factors to account for the total removal of particles. Additional study into the issue of particle removal throughout the HVAC system ductwork, and deposition dependence on ventilation flows, is n
28、eeded to enable such modeling. CONCLUSIONS The capability of the multi-zone IAQ model CONTAM to model the impact of particle clean- ers in an actual building was evaluated. The decay method was found to be more accurate than the direct method for modeling particle air cleaners. With the efficiency o
29、btained in this manner, the air cleaner performance in an unoccupied house was adequately predicted. ACKNOWLEDGEMENTS The authors wish to acknowledge the efforts of Dan Greb, Stuart Dols, Kevin Denton, and Elisabeth Ivy in support of this project and the support of Dilip Vyavaharkar of Carrier Corpo
30、ra- tion in providing technical information and some of the tested air cleaners. REFERENCES Abraham, M.E. 1999. Microanalysis of Indoor Aerosols and the Impact of a Compact High-Efficiency Par- ALA. 1997. Residential Air Cleaning Devices: Types, Effectiveness, and Health Impact. American Lung ANSIIA
31、HAM. 1988. Method for Measuring Performance of Portable Household Electric Cord-Connected ASHRAE. 1992. Gravimetric and Dust-Spot Procedures for Testing Air-Cleaning Devices used in General ASHRAE. 1999. Method of Testing General Ventilation Air-Cleaning Devices for Removal Efficiency by ASHRAE. 198
32、8. Practices for Measurement, Testing, Adjusting and Balancing of Building Heating, Venti- ASHRAE. 1999. Ventilation for Acceptable Indoor Air Quality. ASHRAEStandard 62. ASHRAE. 1991. Handbook of Fundamentals. ASTM. 1991. Standard Guide for Statistical Evaluation of Indoor Air Quality Models. ASTM
33、Standard D5 157-91 American Society for Testing and Materials. ASTM. 1995. Standard Test Method for Determining Air Change in a Single Zone by Means of a Tracer Gas Dilution. ASTM Standard E741-95. ASTM. 1999. Standard Test Method for Determining Air Leakage Rate by Fan Pressurization. ASTM Standard
34、 Ell9-99. Bascom, R., T.K. Fitzgerald, J. Kesavanathan, and D.L. Swift. 1996. A Portable Air Cleaner Partially Reduces the Upper Respiratory Response to Sidestream Tobacco Smoke (1996) Appl. Occup. Environ. Burch, D.M., W.E. Remmert, D.F. Krintz, and C.S. Barnes. 1982. A Field Study of the Effect of
35、 Wall Mass on the Heating and Cooling Loads of Residential Buildings. Proceedings of Building Thermal Mass Seminar. Burroughs, H.E. and K.E. Kinzer. 1998. Improved Filtration in Residential Environments. ASHRAE Jour- nal June 47-5 1. Climet. 1994. Climet Instruments Operating Manual for VersaPort 10
36、. Climet Instruments, Inc. CMHC. 1999. Evaluation of Residential Furnace Filters. Canada Mortgage and Housing Corporation CR. 2000. Breathe Easy. Consumer Reports, January 2000,42-46. ticulate Air (HEPA) Filter System. Indoor Air 9:33-40. Association http:/www.lungusa.org/pub/cleaners/air_clean_toc.
37、html. Room Air Cleaners ANSUAHAM AC-1-1988, Association of Home Appliance Manufacturers. Ventilation for Removing Particulate Matter. ASHRAE Standard 52. I. Particle Size. ASHRAE Standard 52.2. lation, Air-conditioning and Refrigeration Systems ASHRAE Standard l l l. Hyg. 1 l(6): 553-559. Research R
38、eport. 244 HVAC Studies with Mite, Roach, Cat, Mouse and Guinea Pig Antigens. Journal ofrlllergy and Clinical Immunology 76:724. Traynor, G.W., D.W. Anthon, and C.D. Hollowell. 1982. Technique for Determining Pollutant Emissions from a Gas-fired Range. Atmospheric Environment Vol. 16:2979-2987. Wall
39、ace, L. 1996. Indoor Particles: A Review. Journal of the Air for example, Bailey (1951), Fauske (1965), Zaloudek (1965), Benjamin and Miller (1941). EXPERIMENTAL PROCEDURE A typical orifice tube used in air conditioning systems for mobile units is schematically shown in Figure 2. Several such orific
40、e tubes in five nominal diameters were tested in different configurations. All the orifice tubes had the identical housing, the same length, but a different inner diameter. The color of the housing indicates the nominal diameter of the tube. The major elements of the orifice tubes tested are given i
41、n Table 1. As a first step 100 tubes were tested (in sets of 20 according to diameter) by a flow procedure using nitrogen in order to identify a representative unit in each group for testing with refrigerant. The nitrogen test procedure and results are discussed in Singh and Hmjak (2000). In summary
42、, nitrogen flow through the orifice tubes was measured to determine manufacturing variability G.M. Singh is a graduate research assistant, C.W. Bullard is a professor, and P.S. Hrnjak is a research professor, in the Department of Mechanical and Industrial Engineering at the University of Illinois at
43、 Urbana-Champaign. 245 246 HVAC&R RESEARCH 3 ? r i 5 t e x L i c - o C .- E 9 E I .- M II - o a .- .- E $ w M o .- .- E ? E w - e, a 8 m- c a M L - d 8 % m- c a - m .- .- LE 9 P VOLUME 7, NUMBER 3. JULY 2001 241 Table 1. Orifice Tubes Examined Orifice Tube Original Sample Size Inside Diameter, mm Le
44、ngth, mm Brown 20 1.205 38.4 Green 20 1.355 38.4 Orange 20 1.450 38.4 Red 20 1.580 38.4 Blue 20 1.705 38.4 Table 2. Test Matrix-Number of Test Runs for a Given Geometry Screens No Screens Length 38.4 38.4 30.8 23.8 18.4 13.1 TOTALS Color Dia. SL TP SL TP SL TP SL TP SL TP SL TP SL TP ALL Brown 1.205
45、 31 24 31 29 27 13 53 23 22 18 164 107 271 Green 1.355 161 59 161 59 220 Orange 1.45 28 19 23 10 13 O 12 O 76 29 105 Red 1.58 25 25 25 25 50 Blue 1.705 49 31 15 34 26 12 44 31 23 22 157 130 287 TOTAL 294 158 69 73 66 25 109 54 23 22 22 18 583 350 933 Numbers represent data points taken for each comb
46、ination of diameter, length, and inlet flow conditions (SL = subcooled liquid at the inlet, TP = two-phase liquid at the inlet) and to identify a representative sample prior to removing the screens. At least one tube from each sample was tested with refrigerant. After the orifice tube was tested wit
47、h refrigerant, with both inlet and exit screens, both screens were removed and the tests were repeated to quantify the effect of the screens. The purpose of the inlet screen is to serve as a strainer while the exit screen substantially reduces noise generated by the expansion. Subsequently the orifi
48、ce tubes were carefully shortened in steps and tested again. Special care was given in shortening to avoid any change in diameter, shape or geometry of exit plane. The flow rates were measured after each step to verify the effect of length. The test matrix is summarized in Table 2. Values in the cel
49、ls of Table 2 show the number of data points taken for each combination of diameter, length, and inlet flow conditions. SL indicates sub- cooled liquid inlet conditions while TP indicates two-phase inlet conditions. The aim of the test matrix was to cover a wide range of operating parameters to provide the experimental basis for a model that could be used to predict steady and transient flow at normal operating conditions. Tests were conducted in the range of 10 to 33 bar for the upstream pressure, 3.5 to 4.5 bar for the downstream pre
