JP2875373B2 - Water cooler - Google Patents

Description

The present invention relates to the arrangement of baffle plates of a water cooler in a chiller unit.

[Conventional technology]

The arrangement of the baffle plate of the conventional water cooler is such that the pitch of the baffle plate is uniform in the entire region on the cold water side, as described in Japanese Patent Publication No. 88-10269.

[Problems to be solved by the invention]

In the above prior art, the chilled water temperature is high at the chilled water inlet side and the temperature difference from the refrigerant evaporation temperature is large, and the temperature difference between the chilled water temperature at the chilled water outlet side and the region where the refrigerant and chilled water heat exchange characteristics are high is small. In addition, the refrigerant also needs to be gasified and superheated, and the heat exchange characteristic is low in both the regions where the heat exchange characteristics are low, and the flow rate of the chilled water in the region where the heat exchange characteristics are high in the chilled water inlet side region is increased. In addition, no consideration was given to improving the heat exchange characteristics and effective use of the heat transfer tubes, and increasing the number of heat transfer tubes increased the manufacturing cost as a structure that supplemented the cooling performance. . An object of the present invention is to narrow the pitch of the buckle in the chilled water inlet side region, increase the chilled water flow rate, greatly improve the heat exchange characteristic, and increase the buckled pitch in the chilled water outlet side region without increasing the passage resistance of the chilled water. Even when the heat exchange characteristic is reduced, the heat exchange characteristic on the cold water inlet side is covered to improve the cooling performance of the entire water cooler.

[Means for solving the problem]

In order to achieve the above object, the pitch of the baffle is narrowed in the cold water inlet side area, the flow rate of the cold water is increased, the heat exchange characteristic with the refrigerant is improved by the increased flow rate of the cold water, and the pitch of the baffle is increased toward the cold water outlet area. Gradually increase the chilled water passage resistance, and sufficiently compensate for the performance degradation in the area where the chilled water temperature is low and the temperature with the refrigerant is low and the heat exchange characteristics are poor in the chilled water outlet area. In order to improve the cooling performance of the entire water cooler, the baffle pitch was changed between the cold water inlet side and the cold water outlet side.

[Action]

The performance of the water cooler can be expressed by Q = K · A · ΔTM, where Q is the cooling capacity, A is the surface area of the heat transfer tube, ΔTM is the logarithmic average temperature of the cold water temperature and the refrigerant temperature, and K is the heat transfer coefficient. K is Can be represented by alpha _R refrigerant side heat transfer coefficient, alpha _W in the water side heat transfer coefficient, alpha _W is represented by ^{_{α W = av-bv 2 +}} cv 3 formula, a, b, c
Is a constant, v is the water speed, α _R is large at the refrigerant inlet side, and decreases as it goes to the refrigerant outlet side, but is not directly related in the present invention. Α _W increases as the water speed increases, and ΔTM indicates the cold water inlet side. Since the cold water temperature is high, it is higher than the cold water outlet side. That is, since ΔTM is inevitably large in the cold water inlet region, increasing the flow rate of the cold water to increase K in this region has a synergistic effect. For this reason, in the chilled water inlet area, only by narrowing the baffle pitch, the gap of the heat transfer tube does not change, so the chilled water flow rate becomes faster,
performance Q of alpha _W K value is high as a high will result is connexion water cooler operates to increase. Further, in the cold water outlet region, ΔTM is small, and it is a region where improvement in performance cannot be expected from the beginning. Even if the pitch of the baffle is widened and the flow rate of the cold water is reduced, the amount of decrease in the performance Q is small. Therefore, at the cold water inlet side, the baffle pitch is gradually widened as the buffle pitch narrows toward the cold water outlet area, so that the flow rate of the cold water gradually decreases. As a result, the passage resistance of the cold water gradually decreases, so that the passage resistance of the water cooler through the cold water channel does not increase.

〔Example〕

Hereinafter, an embodiment of the present invention will be described with reference to FIG. Cold water flows into the water cooler through the cold water inlet pipe 1. From here, the portion surrounded by the heat transfer tube 3 and the gap between the heat transfer tube and the baffle plate 4 flows outside the heat transfer tube in the shell 2.
The gap between the heat transfer tubes is arranged so as to have a uniform gap over the entire area of the water cooler. Further, the baffle plate 4 is partially cut out so that cold water can move to an adjacent baffle plate 4 alternately. That is, the flow rate of the cold water can be changed by changing the pitch of the baffle plates 4a-n. Here, the pitch of the baffle plates 4a to 4n is narrowed gradually on the inlet side of the cold water, and the pitch of the adjacent baffle plates 4b to n is gradually widened and finally arranged so as to be the widest on the cold water outlet side. That is, the gap between the baffle plate 4a and the baffle plate 4b is the smallest, the gap between the baffle plate 4b and the baffle plate 4c is slightly larger, and the gap is gradually increased as n becomes larger in the baffle plates 4a to 4n. Bappur plate 4n−
The gap between ₁ and baffle plate 4n is arranged to be the widest. Since the gap gradually widens, the flow rate of the cold water gradually decreases. Eventually, the flow rate of the chilled water becomes the slowest, and the chilled water exits from the chilled water outlet pipe 5. According to the present embodiment, the flow rate of the chilled water is the fastest in the chilled water inlet area, and becomes slower as it approaches the chilled water outlet area. Therefore, the heat transfer coefficient of the chilled water is greatly improved in the chilled water inlet area.

〔The invention's effect〕

According to the present invention, the water pitch is changed stepwise, the chilled water flow rate is increased in a region largely affecting the performance of the water cooler in the chilled water inlet region, and the water-side heat transfer coefficient determined by the chilled water flow rate factor is greatly increased. In the area where the logarithmic average temperature is small due to the low chilled water temperature in the chilled water outlet area and the improvement of the water-side heat transfer coefficient cannot be expected even if the chilled water flow rate is increased, the chilled water flow rate is reduced, Since the water-side heat transfer coefficient in the entire water cooler can be improved without increasing the resistance, there is an effect of improving the performance of the water cooler.

[Brief description of the drawings]

FIG. 1 is a sectional view of a water side according to an embodiment of the present invention. 1 ... cold water inlet pipe, 2 ... shell, 3 ... heat transfer tube,
4, 4a to n: baffle plate, 5: cold water outlet pipe, 6: tube plate.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) F28F 9/24 F28F 1/38

Claims (1)

(57) [Claims] In a water cooler including a shell, a tube plate, a heat transfer tube, a baffle plate, and a cold water inlet / outlet pipe, a pitch of the baffle is narrowed in a cold water inlet side region, and the pitch of the baffle is reduced toward a cold water outlet side. A water cooler characterized by gradually widening the pitch of the baffle.