Experimental Study on the Influence of Air Side Equalizing Device on the Flow Heat Transfer Characteristics of Cooling Delta Unit

doi:10.12096/j.2096-4528.pgt.22094

Abstract

Abstract:

For the cooling delta unit, the basic heat transfer element of the cold end of the indirect air-cooling system, the wind speed, air temperature, and wall temperature measuring points were arranged laterally along the heat transfer bundle in the cooling columns on both sides of cooling delta with or without air equalizing apparatus. The wall temperature measuring points were further arranged on the left and right side of water outlet cooling columns. The changes of lateral windward wind speed, wind temperature, wall temperature and outlet water temperature of the cooling columns on both sides along the heat transfer bundles were compared and analyzed. And the influence mechanisms of the air equalizing apparatus on the flow and heat transfer characteristics of the cooling delta unit and the outlet water temperature were studied. The results show that, with the air equalizing apparatus, the distribution of lateral windward wind speed and wall temperature of the two sides cooling columns are more uniform along the heat transfer bundle.

Key words: coal-fired power unit, indirect air-cooling system, cooling delta, air side equalizing device, flow heat transfer, water temperature distribution

CLC Number:

TK 124

Tao GUO, Haiyang YU, Haibo FENG, Hanchuan YUAN, Bing TIAN, Yujie YANG, Yuanbin ZHAO, Qian ZHAO. Experimental Study on the Influence of Air Side Equalizing Device on the Flow Heat Transfer Characteristics of Cooling Delta Unit[J]. Power Generation Technology, 2024, 45(1): 79-89.

Figures/Tables 22

Fig. 1 Relative position of each cooling sectors for a dry cooling tower

Fig. 2 Position of 8 and 9 cooling delta units in the third cooling sector

Fig. 3 Air side equalizing device and the original structure cooling delta unit

Fig. 4 Measurement point installation position of the 8 and 9 cooling delta unit

Fig. 5 Installation location of the wall water column temperature measurement point

Tab. 1 Experimental measurement parameters and instruments

测量参数	仪表	测量范围	测量精度
环境风向	WD4510风向传感器	0~360°	±1°
环境风速	WD4510风速传感器	0~10 m/s	±0.02 m/s
环境风温	温度传感器	-40~+80 ℃	±0.05 ℃
迎风风速	管道式风速仪	0~20 m/s	±0.02 m/s
迎风风温	PT100探针式温度传感器	-50~200 ℃	±0.1 ℃
迎风壁温	PT100贴片贴片温度传感器	-50~200 ℃	±0.1 ℃

Fig. 6 Windward wind velocity distribution of the 8 cooling delta unit cooling column

Fig. 7 Windward wind velocity distribution of the 9 cooling delta unit cooling column

Tab. 2 Range of wind velocity in sector 3

冷却三角	测点迎风风速
冷却三角	L-V1	L-V2	R-V1	R-V2
8号	2.31~4.86	1.57~3.45	1.65~3.77	1.37~5.36
9号	1.39~4.00	3.02~4.01	1.71~5.29	1.57~3.45

Fig. 8 Windward wind temperature distribution of the 8 cooling delta unit cooling column

Fig. 9 TWindward wind temperature distribution of the 9 cooling delta unit cooling column

Tab. 3 The range of wind temperature in sector 3

冷却三角	测点迎风风温
冷却三角	L-V1	L-V2	R-V1	R-V2
8号	10.51~13.07	11.36~13.74	10.20~12.83	10.45~13.20
9号	10.20~12.95	12.22~14.84	8.49~11.18	11.18~13.93

Tab. 4 Range of windward wall temperature in sector 3

位置	测点编号	8号冷却三角	9号冷却三角
左侧冷却柱迎风壁温/℃	L-T1	18.64~21.33	19.49~25.29
	L-T2	18.52~20.96	17.72~20.78
	L-T3	16.44~19.19	17.60~20.47
右侧冷却柱迎风壁温/℃	R-T1	19.43~22.30	19.80~22.55
	R-T2	18.82~21.45	18.52~20.96
	R-T3	17.85~20.59	16.44~19.19

Fig. 10 Windward wall temperature distribution of the 8 cooling delta unit cooling column

Fig. 11 Windward wall temperature distribution of the 9 cooling delta unit cooling column

Tab. 5 Outlet wall temperature of 1 and 2 cooling delta in sector 11 and the data of the environment

时间	1号出水柱壁温/℃	2号出水柱壁温/℃	环境风速/(m/s)	环境温度/℃	环境风向/(°)
13：00	25.23	22.51	2.72	-1.82	199.48
14：00	25.23	22.28	2.95	-1.18	210.15
15：00	24.85	22.86	2.93	-1.20	181.97
16：00	25.07	22.36	2.70	-1.37	168.46
17：00	25.53	22.39	3.14	-1.64	143.36
18：00	26.96	22.31	4.65	-1.88	137.50
19：00	28.27	22.59	5.68	-2.14	132.70
20：00	28.46	22.36	6.10	-2.16	156.71
21：00	28.76	22.15	6.61	-2.14	158.84

Tab. 6 Single side outlet wall temperature of 1 and 2 cooling delta in sector 11

时间	1号冷却三角			2号冷却三角
时间	左侧	右侧	差值	左侧	右侧	差值
13：00	25.34	25.12	0.22	22.64	22.38	0.26
14：00	25.29	25.17	0.12	22.33	22.23	0.11
15：00	24.70	25.00	0.30	21.66	22.07	0.42
16：00	25.03	25.11	0.08	22.32	22.41	0.09
17：00	25.43	25.62	0.19	22.31	22.47	0.16
18：00	26.86	27.06	0.21	22.26	22.36	0.11
19：00	28.38	28.15	0.23	22.65	22.53	0.12
20：00	28.84	28.09	0.75	22.68	22.04	0.65
21：00	28.90	28.63	0.27	22.39	21.91	0.48

Fig. 12 Change trend of 1 and 2 cooling delta units outlet water average temperature and ambient wind direction

Fig. 13 Change trend of 1 and 2 cooling delta units outlet water average temperature and ambient wind velocity

Fig. 14 Change trend of 1 and 2 cooling delta units outlet average water temperature and ambient temperature

Fig. 15 Change trend of the one-sided outlet column water temperature with time

Fig. 16 Change trend of the outlet water column and the temperature water difference of the inlet and outlet water on both sides of the 1 and 2 cooling delta units

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