Measurement and analysis of the velocity field at

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Test and analysis of the velocity field at the outlet of cabinet air conditioner

1 preface

with the wide application of split air conditioner in people's daily life and work, its comprehensive performance has been paid more and more attention. Refrigeration (heat) capacity and noise are the two main indicators of air conditioners, and the qigong performance and noise characteristics of indoor units of air conditioners are the concrete embodiment of these two indicators. Due to space constraints, the flow channel of the air conditioner is very narrow, and various components in the pipe, such as air inlet panel, evaporator, air outlet form, etc., have a great impact on the flow of air. Therefore, the qigong performance of air conditioners is generally poor and the flow loss is large. In order to improve the flow efficiency and optimize the internal structure of the indoor unit, we tested the velocity flow field at the outlet of the cabinet air conditioner. Through analyzing and understanding the basic causes of the loss, the approximate location of the loss source is determined

2 test device and method

2.1 test device

test device is shown in Figure 1. This test system includes kf-60l/e, TSI speedometer, recorder and computer of indoor unit of cabinet air conditioner. The TSI speedometer model is tsi8384a-m-gb, with reading accuracy of ± 3%, output accuracy of 0.015m/s, range of 0.0~80m/s, resolution of 0.13. For experiments that need to be done in high temperature environment, M/s. During the test, the outlet deflector was horizontal. The TSI probe is installed horizontally and aligned with the outlet air flow, 40mm away from the outlet surface

2.2 layout of measuring points

the air outlet of the test prototype is 400mm long and 220mm high. There are six horizontal adjustable deflectors with a thickness of 4mm at the air outlet. In the vertical direction, a vertical fixed deflector with a thickness of 6mm is located in the middle, and two thickness deflectors are distributed on both sides. 1. A total of 97.02% of the respondents expressed concern about the market and Technological Development of circular economy, and the vertical fixed deflector with a thickness of 2mm. For the convenience of measurement and analysis, the measurement space in the vertical direction from top to bottom is defined as a~g, and the horizontal direction from left to right is defined as I ~ VII. Each horizontal area is measured from I ~ VII, and according to the spatial size of each area, an intermediate measurement point is allocated to areas I and VII respectively, while four measurement points are allocated to the other four areas equally. Therefore, there are 19 measuring points in each horizontal area from a to g, and 133 measuring points are arranged in the whole air outlet. As shown in the figure

3 test results

according to the layout of the measuring points in the diagram, the measured speed values of each point are shown in Table 1

4 data analysis

according to the data in Table 1, the velocities and their average values of 7 horizontal sections are shown in Figure 3 and figure 5 respectively, and the average velocities of 19 vertical sections are shown in Figure 4

it can be seen from Figure 3 that each curve has obvious concave lines, which clearly indicate the influence of the wake vortex generated by the fixed vertical deflector on the air flow. It can also be seen from the figure that the area near the measuring points 9, 10 and 11 is greatly affected, because the thickness of the middle deflector (6mm) is larger than that of other deflectors. At the same time, the velocities at the left and right ends of each curve in Figure 3 and Figure 4 are low, indicating that the left and right side walls of the box have a great impact on the air flow velocity, especially in the area near the right wall, the lowest value of the velocity appears, and the velocity changes significantly. This is mainly because the air flow in this area is not only affected by the wall, but also affected by the refrigeration pipeline and accessories installed on the right side of the evaporator. It can be seen that this is an important loss source that cannot be ignored

from the vertical direction, figures 3 and 5 show that the cross-sectional velocity close to the upper wall is small, indicating that the 900 corner of the upper wall has a great impact on the flow. In addition, the velocity of section g near the lower wall is significantly lower than that of section F, which convinces us that the shadow of the lower wall on the flow makes us distinctive

from the above analysis, it can be seen that the thickness and shape of the guide vane at the outlet of the indoor unit of the cabinet air conditioner, the upper, lower, left and right walls, the angle of the corner, and the installation position of the evaporator and its pipeline accessories all affect the air flow, resulting in a large internal flow loss. Based on these analyses, the internal structure of the indoor group of cabinet air conditioners should be further optimized

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