Second, the "blank test" data 1. "blank test"
The “blank test†is a reflection of the comprehensive error of the equipment. The test error is due to the fact that there are indeed factors in the gas permeability test that cannot be effectively improved, such as system leaks and other unpredictable factors. Although there has been no clear "blank test" in the air permeability test standard, the test work on the "blank test" has been widely recognized by the society.
2. VAC-V1 “Blank Test†Data In order to obtain the comprehensive impact value of all factors, VAC-V1 uses a sample that is considered to be completely airtight to be tested according to normal operating procedures, and then to observe system leakage and other factors for the entire device. The combined impact. The "blank test" value obtained by this method determines the pros and cons of the device to be more credible.
Labthink VAC-V1's "blank test" uses 55μm copper foil (also can use thicker aluminum foil sample) as a sample to test, strictly sealed, the system is vacuumed for 48h (before entering the test state, the vacuum of the upper and lower chambers should be Below 10 Pa), the test was carried out using the conventional volume of the VAC-V1 (the device has an optional extended volume function). In order to analyze the influence of environmental temperature and humidity changes on the test, there is no self-temperature control function of the starting device. The pressure time curve is obtained as shown in Fig. 1. (In addition, there are temperature time and humidity time curves, which will not be described here)
The test lasted for 12 days (including vacuuming time), the temperature was between 18 and 23 °C, and the ambient humidity was 50±8% RH (if the self-temperature control function of the equipment was used, the test effect was better). After entering the test state, the lower chamber pressure increased by 6.0 Pa, and the test result was 0.023 ml / m 2 · 24 h · 0.1 MPa (if the extended volume or fuzzy test mode is selected, the comprehensive effects of the above various factors can be effectively reduced, and the obtained The test results will be more accurate). It is not difficult to find out that the influence of temperature and humidity changes on the test is small when the whole test curve is analyzed with the data list.
During the first 60 hours, the pressure change was relatively large, rising from 0 Pa to 3.84 Pa. In the subsequent 180 h, the pressure increase was decreased, and the equivalent gas permeability was 0.012 ml/m 2 · 24 h · 0.1 MPa. The reason for this phenomenon is related to the degassing state. The test proves that prolonging the vacuuming time can effectively improve the impact on the test results.
Third, data repeatability 1. The factor of data repeatability is due to the large gap between the components selected by each manufacturer when implementing a test method. Therefore, the data repeatability of the equipment is also an important indicator for evaluating equipment. By analyzing the data repeatability of the device, it is possible to better understand the error and fluctuation of the detection data of the device and improve the detection efficiency. Data repeatability includes: S (standard deviation standard deviation), CV (percent coefficient of variation data fluctuation percentage) and LSD (least significant difference between two individual test results based on a 95% confidence level confidence level 95% of two independent test results Minimum effective difference).
Membrane/Water Wall Material and Arrangement:
The
furnace and roof are made up of membrane water wall and hung on the
steel structure by upper hanging suspender of water cooling upper
header. Furnace intersecting surface is 3170×5290mm2 and
the elevation of top furnace is 28877mm. The membrane water wall is
made up of φ60×5 and 6×45 welding steel flat. The combustion chamber is
made of φ60×4 steel tube and welded with pin to fasten refractory
material. The upper part of combustion chamber connects with furnace
membrane water wall. The lower part connects with water cooling wind
chamber and water cooling air distributor. The water cooling wind
chamber is made up of φ60 steel tube and welded with pins to fasten the
refractory material. The water cooling distributor is welded with
φ60 steel tube and 6X45 steel flat. The small holes on the steel flat
connects with the funnel cap.
The
furnace divides left, right, front and back water circulation circuit.
The steam leading tube is made up of φ133×5 and φ108×4.5 steel tube. The
downcomer is made up of φ108×4.5 steel tube. Install the blowdown valve
under the lower header to periodic blow down.
Heat Surface,Scraped Surface,Heat Transfer Surface,Heating Surface For Coal Boilers
Jinan Boiler Group Co., Ltd. , https://www.jinanboiler.com