1、OR-05-15-1 (RP-1191) Field Evaluation of Ventilation and Control of Diesel Exhaust in Enclosed Locomotive Amy Musser, PhD, PE Associate Member ASHRAE ABSTRACT This paper summarizes the results ofjeld measurements that were conducted in four operating diesel locomotive shops. Thephysicalgeometry and
2、ventilation system design are docu- mented for each shop, and their usage is described. Measure- ments taken over a four-day period at each location are discussed, and typical data are presented. When possible, average contaminant concentrations for similar operating events are also analyzed togethe
3、r to provide a more complete assessment of ventilation system operation. Finally, qualita- tive observations gathered during thejeld study that may be useful to designers are discussed. These include insights on locomotive position within the shop, control issues, and the importance of temperature i
4、n certain types of design. INTRODUCTION Currently available design guidance for ventilation of enclosed locomotive facilities has been developed based on practical experience. However, little research exists to validate or invalidate the effectiveness of these ventilation quantities for removal of d
5、iesel exhaust. Furthermore, there is little inde- pendent published information that surveys current practice and reports routine operating experiences. This work describes field measurements that were conducted in four shops located in the United States under normal operating conditions. There were
6、 several goals of this study. First, the design of each ventilation system was docu- mented and described. Second, contaminant measurements were collected to compare and evaluate the various systems and also to provide validation data that can be used to develop a computational model. Also, addition
7、al information was collected while visiting the shops that may be useful to design- Faci I it es Matthew Radik Student Member ASHRAE ers in planning future systems. The final goal of this effort, combined with future CFD modeling, is to develop handbook appropriate material to guide the design proce
8、ss for these facilities. Several sources provide design and operations guidance relevant to ventilation of railroad facilities. The ventilation rate procedure of ASHRAE Standard 62-2001, Gntilation for Acceptable Indoor Air Quality, specifies 1.5 cfinlft2 (7.5 LIS per m2) to maintain acceptable indo
9、or air qualiy in auto repair rooms, which is the closest listed occupancy (ASHRAE 2001). However, locomotive facilities tend to have high ceil- ings and larger volumes, so the 1999 ASHME ffandbook- Applications recommends that a volumetric model instead be used to calculate the design ventilation (A
10、SHRAE 1999). Both the ASHRAE Handbook-Applications and the Ameri- can Railway Engineering and Maintenance-of-Way Associa- tion (AREMA) Manual for Railway Engineering suggest 6 air changes per hour when dilution ventilation is used (AREMA 2001). These values provide a benchmark for comparing the syst
11、ems analyzed here. FIELD MEASUREMENTS Test Protocols The test protocol implemented at the shops included oper- ations monitoring, contaminant, and temperature arrays inside the shop, ventilation assessment, and weather monitoring. Because the purpose of the measurements was to characterize the respo
12、nse of the ventilation system to locomotive operation, contaminant and temperature arrays in each shop were set up near tracks that experienced the most locomotive movement. In some cases, it was possible to leave the arrays in one loca- tion for several hours each day. In shops that experienced les
13、s Amy Musser is a partner at Vandemusser Design, LLC, Asheville, NC. Matthew Radik is a student at the University of Nebraska, Omaha, Neb. O2005 ASHRAE. 1015 traffic, it was necessary to move the arrays based on the planned daily schedule. During the times when instruments were installed, all locomo
14、tive movement and operation were recorded. This was done not just for the track adjacent to the instrument array, but for all tracks in the shop. Vertical contaminant and temperature arrays were set up inside the shop to obtain profiles that could be used for vali- dation of a computational model. I
15、n most cases the array consisted of three sets of sensors that were either hung from the ceiling structure or mounted on a telescoping pole. These sensors were capable of collecting time series data for up to eight hours at a time. In all of the shops, electrochemical sensors capable of measuring ca
16、rbon monoxide, nitric oxide, and nitrogen diox- ide were installed. Manufacturer information for the carbon monoxide sensor states a range of 0-500 ppm, a resolution of 1 ppm, a cross-reactivity without filtering of 3 ppm to 35 ppmNO, and-1 ppm to 5 ppmN0,. The nitric oxide sensor has a range of 0-2
17、50 ppm, a resolution of 1 ppm, no cross-reac- tivity to 300 ppm CO, and 1.5 ppm cross-reactivity to 5 ppm NO,. The nitrogen dioxide sensor has a range of 0-30 ppm, a resolution of O. 1 ppm, a cross-reactivity of 15 ppm to 300 ppm CO, and no cross reactivity to 35 ppm NO. The temperature sensors have
18、 a range of 4OF to 158F (-20C to 70C). They have a resolution of O.8“F at 68F (0.4“C at 20C) and about 1.2“F at 140F (0.7“C at 60C). At one of the sites, carbon dioxide sensors were also installed. These sensors have a range of 0-4000 ppm when used with a data logger and a resolution of 50 ppm. They
19、 were not deployed at the other sites because the recorded variation in CO, that accompanied locomotive operation was not much larger than the normal fluctuations observed throughout the day. Therefore, they were not useful as an indicator of loco- motive operation. Mechanical flow rates were verifi
20、ed in a number of ways, depending primarily on equipment accessibility. Manufac- turer ratings were taken fi-om drawings and nameplate infor- mation. When possible, flow rates were verified by pitot tube duct traverse or traverse-type measurements at air outlets. Although the latter method is not a
21、particularly accurate Site la lb 2 method of determining airflow (order *20%), it does provide a means of verifiing the rated equipment flow rates. Outdoor wind speed, temperature, and relative humidity were recorded using a weather station mounted on the roof of each shop. Due to some lapses in our
22、 data recording device, hourly average weather data recorded at nearby airports were also obtained from a weather service and used when needed to supplement the collected data. These data were primarily collected to assist in developing computational models of the facilities. Shop Area Ceiling Heigh
23、t Exhaust Airflow Air Change Location (ftY Volume (ft?) Ventilation System Rate (cfm) Rate (hr-) Chicago 12,800 42 537,600 General exhaust 60,000 6.7 Chicago 12,800 42 537,600 General exhaust 72,000 - 102,000 8 - 1 1.3 New Orleans 21,600 19.5 and 34.5 543,000 Gcncral exhaust 5 19,000 57 Test Schedul
24、e The four sites studied were locomotive repair shops located throughout the United States. Pilot tests were conducted at site 1 for two days in December 200 1. A second visit of three days duration was then made to this location in March 2002. Because of a calibration problem that was later discove
25、red, the nitrogen dioxide concentration data collected at this site are unreliable and are not presented here. The protocol for the remaining tests allowed for four days at each site. The first day was reserved for setup and planning, and the remaining three days were used for data collection. A tri
26、p to site 2 was completed in May 2002, and a trip to site 3 took place in June 2002. Site 4 was monitored in July 2002. 3a 3b 4 Test Sites A brief description of each site and its ventilation system follows. These data are based on drawings, when available, as- built conditions verified on the site
27、visits, manufacturer infor- mation, and ventilation system measurements. Table 1 summarizes shop characteristics and exhaust volumes for all of the sites. Site i: This shop is located in Chicago. The facility is actually made up of two connected structures. The first, site la, is used for fueling an
28、d washing locomotives. The second, site lb, is used for daily service and repair. The two structures are oriented such that locomotives first pull in to the fueling facility from the south, move forward through it into the repair Los Angeles 20,400 42 (avg.) 855,400 Natural and general 180,000 12.6
29、Los Angeles 1 1,000 37 (avg.) 406,000 Natural and hoods 40,000 5.9 Rensselaer, NY 64,000 39 (avg.) 2,490,000 General exhaust and 320,000 - 371,000 7.7-8.9 heating Table 1. Summary of Shop Characteristics * Reported ceiling heights are rail to ceiling, and do not account for solid platforms. 1016 ASH
30、RAE Transactions: Symposia Exhaust fan Exhaust fan I I Track 3 Treck 2 Track 1 Section View A-A Figure 1 Site 1 section viewsewice and repair shop. facility, and exit to the north. Both of these facilities are heated in the winter. A section view of the service and repair facility is shown in Figure
31、 I. The fueling facility shares the same phys- ical arrangement but has a different ventilation system. The fueling facility, site 1 a, is heated and ventilated using three roof-mounted heat recovery units that operate year- ment. Locomotives can and do idle at all positions located on the tracks, a
32、nd the ventilation system does not assume a loco- motive position. However, the locations of servicing equip- ment, such as the fueling tanks, do create patterns of movement and would allow the more common standing loca- tions to be identified. round for ventilation. Supply ducts are mounted vertica
33、lly on the exterior walls, and air is supplied near the occupied zone. Air is removed at the ceiling level. These units each supply approximately 20,000 cfm (9,438 L/s) of outdoor air for venti- lation. The exterior doors on the south end of this shop remain open year-round. During the winter months
34、, an air curtain is used to reduce infiltration from outdoors. Site 1 b, the service and repair shop, is heated by three air- handling units that provide 30,000 cfm (14,157 L/s) each of total supply air via ducts mounted overhead. These units provide approximately 10,000 cfin (4,7 19 L/s) of outdoor
35、 air each, and they are operated only during the heating season. This shop also makes use of four large exhaust fans, which Site 2: This shop, shown in Figure 2, is located in the hot and humid climate of New Orleans. It contains four tracks, each of which can accommodate two locomotives indoors. Tr
36、acks 1 and 4 are primarily used for extensive repairs and rebuilds. Track 2 is usually used for 90-day inspections and other repairs that require one to three days to complete. Track 3 is most often used for routine maintenance activities, which usually require about an hour. Often, locomotives are
37、running on Track 3 for that duration. Therefore, measurement arrays at this site were usually deployed adjacent to Track 3. The arrays were moved to Track 2 for a few short periods when locomo- tive movement was planned on that track. - operate continuously at approximately 18,000 cfm (8,494 L/s) ea
38、ch. Since our measurements were conducted during the heating season, this shop was operating at the higher air change rate during our tests. Both shops contain three tracks. These shops are heavily utilized, and ali tracks experience frequent locomotive move- Locomotives are moved into the shop thro
39、ugh four large doors on the east end of the building that remain open. Loco- motives on Track 4 can be pulled through and out the west side of the building, but locomotives on the other tracks must be backed out of the east end doors. One notable aspect of loco- motive operation in this shop is that
40、 locomotives are almost ASHRAE Transactions: Symposia 1017 Exhausi Fan Typical insirumeni Location Section View A-A Figure 2 Site 2 section view always pulled completely forward, and are therefore parked in the same location most of the time. This shop has many openings for natural ventilation. In a
41、ddition to the four large open doors on the east side, there are rows of windows located at a height of about 10 ft (3 m) from the ground on the north and south walls. The shop is mechan- ically ventilated using a general exhaust system that utilizes 23 roof-mounted exhaust hoods at approximately 22
42、,500 cfm (10,618 L/s) each. These are located above the four tracks. Personnel in the shop are able to manually start and stop these exhaust fans, but they remained on almost constantly during our visit. The only reason identified for turning them off was that they generate a moderate amount of nois
43、e, but since they also make a significant contribution to keeping the shop cool in this hot climate, they tended to remain on. This may be somewhat less likely to occur in the winter months. All fans in this shop are normally switched on and off together. However, since they are installed with expos
44、ed belts, fan failures are relatively common. The large number of fans, therefore, helps to maintain high exhaust flow rates even when some ofthe fans may not be operational. Since repairs had been performed just prior to our visit, all ofthe fans were operating during our tests. Site 3: This shop i
45、s located in Los Angeles, which expe- riences warm, dry weather. Unlike all of the other shops, which operate on a 24/7 basis, this shop does not perform daily service and therefore operates on a single daytime shift. It is composed of two areas, connected by a large, open wall, as shown in Figure 3
46、. The larger section, referred to here as site 3a, houses two tracks (3 and 4) and an elevated, enclosed office. The smaller section, site 3b, contains two additional tracks (i and 2). The tracks are oriented in the north-south direction, so that locomotives can enter from either end of the shop and
47、 exit at the opposite end. The two shops are used and ventilated differently. The larger section, referred to here as site 3a, has a higher roof and has natural ventilation openings along the roofline and a general exhaust system. This shop has a peaked roof, with 4 ft (1.2 m) high natural ventilati
48、on openings at the top of the wall that run the length of the building on both sides. Six 30,000 cfm (14,157 L/s) exhaust fans are mounted at the roof level, spaced evenly along its length. The smaller shop, site 3b, is connected to the east side of the larger shop and has most of its remaining thre
49、e sides open to the outdoors. Large exhaust hoods are installed over each of the tracks. The hood configuration consists of a 90 ft (27 m) length of duct, with anarrow slot opening with 1.5 in. (38 mm) width, through which 20,000 cfm (9,438 L/s) is drawn. Flex- ible curtains hang from either side ofthe duct to guide the loco- motive exhaust into the hood. Site 3b is typically used for inspections and other rela- tively quick turnaround work. Operation is limited to idling and low throttle speeds when moving in and out. It was orig- inally intended that this area be used for proc
