JP2587370B2 - Freezing prevention device for closed cooling tower - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for preventing freezing of a closed cooling tower, which prevents a heat exchanger from freezing when the cooling tower is stopped in winter.

[0002]

2. Description of the Related Art When a closed cooling tower is used in winter, the heat exchanger may freeze due to a decrease in outside air temperature when the operation is stopped and may be damaged. As a method of preventing this freezing, a method of cooling the heat exchanger and mixing an antifreeze into the secondary cooling water circulating between the heat exchanger and the load, separately from the primary cooling water contacting the outside air, Either a method of forcibly circulating the entire amount of cooling water to be cooled is adopted.

[0003]

However, the method of mixing the antifreeze into the secondary cooling water involves setting and controlling the concentration of the antifreeze according to the outside air temperature, requiring maintenance and inspection, and running the antifreeze because it is expensive. The cost is also high. In addition, the method of circulating the entire amount of the secondary cooling water circulates the cooling water of the entire facility other than the place necessary for preventing freezing, so that the power consumption of the cooling water circulation pump becomes expensive and energy is wasted significantly. Becomes

An object of the present invention is to provide a spraying water pump with a cooling water pipe in parallel with the spraying water pipe, and to circulate the cooling water by the spraying water pump when the operation of the cooling tower is stopped to prevent the heat exchanger from freezing. And

[0005]

SUMMARY OF THE INVENTION The present invention has been made to achieve the above object, and has a cooling water circuit for circulating cooling water between a heat exchanger and a load, cooling the heat exchanger, and spraying water. In a cooling tower having a spray water circuit provided with a pump, a parallel cooling water circuit that circulates a heat exchanger and a spray water pump through a switching valve at each of an inlet side and an outlet side of the spray water pump is formed. The gist of the invention is that when the operation is stopped, cooling water is circulated only to the heat exchanger by the spray water pump to prevent freezing.

[0006]

The switching valves 9a and 9 are provided between the closed cooling tower 1 and the spray water pump 4 separately from the normal spray water pipe 6.
b, 9c, 9d, parallel cooling water pipes 8A, 8B are provided. During normal operation, the switching valves 9a, 9b are opened to open the spray water pipe side 6, and the parallel cooling water pipes 8A, 8B are opened.
By closing the B side, the operating state becomes the same as the conventional one. When the operation of the cooling tower is stopped, the switching valves 9a and 9b are closed to close the spray water pipe side 6, the switching valves 9c and 9d are opened to open the parallel cooling water pipe sides 8A and 8B, and only the spray water pump 4 is operated. When driving, at this time,
As for the cooling water, only the heat exchanger section 2 is connected in parallel with the cooling water pipes 8A and 8B.
Thus, it is possible to prevent the heat exchanger from freezing without circulating the entire cooling water unlike the related art.

[0007]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing an embodiment of the present invention; In the figure, reference numeral 1 denotes a closed cooling tower having a required capacity. A heat exchanger 2 is housed in the closed cooling tower 1 and cooling water is circulated through the heat exchanger 2, a load 3 and a cooling water pump 5. A pipe 7 is provided to cool the load 3.

After the primary cooling water and the heat exchanger 2 are cooled by the spray water pump 4 in the closed cooling tower 1,
A spray water pipe 6 is provided so as to circulate so as to exchange heat with the atmosphere. Switching valves 9a and 9b are provided in the spray water pipe 6 and on the inlet side and the outlet side of the spray water pump 4, respectively.

In the present invention, the cooling water pipe 7 and the spray water pipe 6 are independent of each other, but in the present invention, they are connected to each other by parallel cooling water pipes 8A and 8B. That is, one parallel cooling water pipe 8A branches off from the cooling water pipe 7 on the way to the heat exchanger 2 via the cooling water pump 5, and is connected to the outlet side spray water pipe 6 of the spray water pump 4 via the switching valve 9d. And the other parallel cooling water pipe 8B
Is branched from the cooling water pipe 7 between the heat exchanger 2 and the load 3 and is connected to the inlet side spray water pipe 6 of the spray water pump 4 via the switching valve 9c.

Therefore, in the circuit composed of the cooling water pipe 7, the spray water pipe 6, and the parallel cooling water pipes 8A and 8B as described above, the switching valves 9a and 9b are opened during normal operation, and
When c and 9d are closed and the spray water pipe 6 is used as a circulation path, and the parallel cooling water pipes 8A and 8B are closed and the pumps 4 and 5 are operated, the same operating state as the conventional closed cooling tower is obtained.

When the operation of the cooling tower is stopped in winter or the like, the parallel cooling water pipes 8A, 8B
The cooling water is circulated only in the part to prevent the heat exchanger from freezing. That is, the switching valves 9a and 9b are fully closed, the switching valves 9c and 9d are fully opened, and only the spray water pump 4 is operated. Thus, a circulation circuit is sequentially formed through the parallel cooling water pipe 8A, the heat exchanger 2, the parallel cooling water pipe 8B, and the spray water pump 4, and the cooling water circulates only through the circulation circuit passing only through the heat exchanger. Only by circulating a small amount, freezing of the heat exchanger can be prevented.

[0012]

According to the present invention, there is provided an antifreezing device for a closed type cooling tower, comprising: a cooling water circuit for circulating cooling water between a heat exchanger and a load; and a spray water circuit for cooling the heat exchanger and having a spray water pump. In the cooling tower equipped with a water spray pump, a parallel cooling water circuit that circulates the heat exchanger and the spray water pump via the switching valve at the inlet side and the outlet side of the spray water pump respectively is formed. Since the cooling water is circulated through the heat exchanger in the above, there is an advantage that freezing can be prevented with less energy.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing an embodiment of an apparatus for preventing freezing of a closed cooling tower according to the present invention.

FIG. 2 is a circuit diagram of a known example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Closed cooling tower 2 Heat exchanger 3 Load 4 Spray water pump 5 Cooling water pump 6 Spray water pipe 7 Cooling water pipe 8A, 8B Parallel cooling water pipe 9a, 9b, 9c, 9d Switching valve

Claims (1)

(57) [Claims] 1. A cooling tower having a cooling water circuit for circulating cooling water between a heat exchanger and a load, and a spray water circuit for cooling the heat exchanger and having a spray water pump. A parallel cooling water circuit that circulates the heat exchanger and the spray water pump through the switching valve on the side and the outlet side respectively, and circulates the cooling water only to the heat exchanger with the spray water pump when the operation of the cooling tower is stopped An anti-freezing device for a closed-type cooling tower, wherein the anti-freezing device is adapted to prevent freezing.