Wind-break walls with optimized setting angles for natural draft dry cooling tower with vertical radiators

Abstract

To get larger cooling performance enhancement for natural draft dry cooling tower with vertical cooling deltas under crosswind, setting angles of windbreak walls were optimized. Considering specific structure of each cooling delta, an efficient numerical model was established and validated by some published results. Aerodynamic fields around cooling deltas under various crosswind speeds were presented, and outlet water temperatures of the two columns of cooling delta were exported as well. It was found that for each cooling delta, there was a difference in cooling performance between the two columns, which is closely related to the characteristic of main airflow outside the tower. Using the present model, air inflow deviation angles at cooling deltas' inlet were calculated, and the effects of air inflow deviation on outlet water temperatures of the two columns for corresponding cooling delta were explained in detail. Subsequently, at cooling deltas' inlet along radial direction of the tower, setting angles of windbreak walls were optimized equal to air inflow deviation angles when no airflow separation appeared outside the tower, while equal to zero when outside airflow separation occurred. In addition, windbreak walls with optimized setting angles were verified to be extremely effective, compared to the previous radial walls.

Utilization of the lateral accelerated cross-wind to improve the cooling performance of a natural draft dry cooling tower

“…S1013-S1024 cooling performance of a NDDCT. Since CFD method is convenient to reveal the comprehensive flow field information, it is increasingly adopted in studying the performance of a NDDCT [7][8][9]. In order to conjointly study the NDDCT performance, a specially designed hot state test rig built in a wind tunnel is also reported [10,11].…”

Performance Recovery of Natural Draft Dry Cooling Systems by Combined Air Leading Strategies

“…Gu et al [22] optimized various windbreak structures (cross wall, windbreak wall, cross line-screen and louvers) for dry-cooling tower. With the windbreak walls installed at the heat exchanger inlet, Ma et al [23] pointed out that the windbreak wall angle should equal the inflow deviation angle without airflow separation. What's more, the enclosure type of windbreakers around the heat exchanger was also suggested for NDDCS [24,25], by which not only the cooling performance is improved, but the wind momentum can also be used.…”

Numerical and experimental study of small natural draft dry cooling tower for concentrating solar thermal power plant

“…The combined wall could provide both function and the air mass flow rate through the heat exchanger can be therefore increased. It is noted that no matter which kind of windbreak wall, the wind direction has a significant effect on the performance of these windbreakers [74,80,109,113]. For example, in Lu's [74] research on the internal tri-blade windbreak wall, they found that the effect could be varied more than 30% with different crosswind direction.…”

“…For example, in Lu's [74] research on the internal tri-blade windbreak wall, they found that the effect could be varied more than 30% with different crosswind direction. While most of the external windbreaker is radial direction, Ma et al [113] investigated the optimal setting angels for the external windbreak wall. They claimed that under certain crosswind speed and direction, the windbreak walls with optimised angle have better performance than the conventional radial ones.…”

“…They found the windbreak walls enhancing the performance of the cooling tower at certain wind speeds. Ma et al [87,113] studied the angles of the windbreak wall for a NDDCT with vertical heat exchanger. Their research found that the optimized walls can reduce the interference on airflow at low wind speeds and create a strong secondary flow at high wind speeds.…”