JP2008224198A - Freezing preventive device of sealed cooling tower - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a freezing preventive device of a sealed cooling tower capable of reducing energy cost for operation of a freezing preventive circuit, and without polluting cooling water when the cooling water contacts with spraying water, even when operating the freezing preventive circuit, when stopping operation of the sealed cooling tower. <P>SOLUTION: This freezing preventive device 10 in the sealed cooling tower 1 is composed of a cooling water circuit C1 for circulating the cooling water between a heat exchanger 2 and a load 3 by a cooling water pump 4, and a spraying water circuit C2 for circulating spraying water for cooling the heat exchanger 2 by a spraying water pump 5, and prevents freezing of the heat exchanger 2 by circulating the cooling water when stopping the operation of the sealed cooling tower. A freezing preventive circuit C3 is constituted for circulating the cooling water to the heat exchanger 2 by a freezing preventive pump 12, by arranging the freezing preventive pump 12 in a bypass passage 11, by forming the bypass passage 11 bypassing the cooling water pump 4 in the cooling water circuit C1. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a freeze prevention device for a hermetic cooling tower, and more particularly to a freeze prevention device for a hermetic cooling tower that prevents the heat exchanger from freezing when the operation of the hermetic cooling tower is stopped.

Normally, the closed cooling tower 20 includes a cooling water circuit C4 in which cooling water circulates between the heat exchanger 2 and the load 3 by the cooling water pump 4, and the spray water pump 5 as shown in FIGS. Is provided with a spray water circuit C5 through which spray water for cooling the heat exchanger 2 circulates.
The spray water circuit C5 sprays spray water from the water tank 6 disposed in the upper part of the housing 8 with respect to the heat exchanger 2 disposed in the housing 8 of the hermetic cooling tower 20. ing.
This sprayed water cools the heat exchanger 2 through which the cooling water that has been heated by cooling the load 3 passes, and accumulates in the water tank 7 disposed in the lower part of the housing 8. It is sent to the watering tank 6.
Further, when the spray water flows down through the heat exchanger 2, air (outside air) sucked from a louver (not shown) formed on the side surface of the housing 8 by the fan 13 provided on the upper portion of the housing 8. Cooled by.

  By the way, when the operation of the hermetic cooling tower 20 is stopped in winter when the outside air temperature is low, there is a problem that the heat exchanger 2 is frozen due to a decrease in the temperature of the cooling water in the cooling water circuit C4 and is damaged. In order to solve the problem, when the operation of the closed cooling tower 20 is stopped, the cooling water in the cooling water circuit C4 is removed or the operation of the cooling water pump 4 is continued to continuously circulate the cooling water in the cooling water circuit C4. Has been used.

However, in order to extract the cooling water remaining in the heat exchanger 2, it is necessary to drain the air by sending it into the heat exchanger 2 using an air compressor.
On the other hand, although the cooling water pump 4 varies depending on the capacity (scale) of the load 3, since a large pump is usually used, the operation of the cooling water pump 4 cannot be continued when the closed cooling tower 20 is stopped. There is a problem that the energy cost increases.

  In order to cope with this problem, the hermetic cooling tower shown in FIGS. 5 to 6 is provided with an anti-freezing device 30 (see, for example, Patent Document 1).

  In the hermetic cooling tower freezing prevention device 30, switching valves V <b> 5 to V <b> 8 are arranged on the inlet side and the outlet side of the spray water pump 5.

  In the normal operation of the closed cooling tower 20, both the cooling water pump 4 and the spray water pump are operated, the switching valves V5 and V6 are opened, and the switching valves V7 and V8 are closed. As shown, a cooling water circuit C4 and a spray water circuit C5 are configured.

On the other hand, when the operation is stopped in the winter when the outside air temperature is low, both the cooling water pump 4 and the spray water pump are stopped, the switching valves V5 and V6 are closed, and the switching valves V7 and V8 are opened. As shown in FIG. 3, the freeze prevention circuit C6 is configured.
Since the sprinkling water pump 5 is generally a smaller pump than the cooling water pump 4, the energy cost of the antifreezing circuit C6 that operates when the hermetic cooling tower 20 is stopped can be somewhat reduced. There is.

However, since the freeze prevention device 30 of the hermetic cooling tower uses the spray water pump during the operation of the freeze prevention circuit C6, the spray water circulating through the spray water circuit C5 and the cooling water circulating through the cooling water circuit C4 There was a problem that the cooling water was contaminated.
JP 7-35484 A

  In view of the problems of the conventional anti-freezing device for a hermetic cooling tower, the present invention has a low energy cost for operating the anti-freezing circuit even during operation of the anti-freezing circuit when the operation of the hermetic cooling tower is stopped. It is another object of the present invention to provide an antifreezing device for a hermetic cooling tower in which the cooling water is not contaminated by contact between the cooling water and the spray water.

  In order to achieve the above object, a freeze prevention device for a hermetic cooling tower according to the present invention includes a cooling water circuit in which cooling water circulates between a heat exchanger and a load by a cooling water pump, and a heat exchanger by a spray water pump. In the anti-freezing device in the closed cooling tower, which prevents the heat exchanger from freezing by circulating the cooling water when the closed cooling tower is shut down, Forming a detour circuit that bypasses the cooling water pump in the circuit, arranging an antifreeze pump in the detour circuit, and configuring an antifreeze circuit that circulates cooling water to the heat exchanger by the antifreeze pump It is characterized by.

According to the freeze prevention device for a hermetic cooling tower of the present invention, a detour that bypasses the cooling water pump in the cooling water circuit is formed, and the antifreezing pump is disposed in the detour, and heat exchange is performed by the antifreeze pump. By constructing an anti-freezing circuit that circulates the cooling water in the vessel, the cooling water is not in contact with the cooling water and the spray water even during operation of the anti-freezing circuit when the closed cooling tower is shut down. There is no contamination.
In addition, the anti-freezing pump disposed in the anti-freezing circuit only needs to have a capacity that allows the cooling water to circulate through the anti-freezing circuit, so that a small pump can be used, which greatly increases the energy cost. Can be reduced.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a freeze prevention device for a hermetic cooling tower according to the present invention will be described below with reference to the drawings.
In addition, about the structure similar to a conventional apparatus, the same code | symbol and a series of code | symbol are attached | subjected, and description is abbreviate | omitted.

  1 to 2 show an embodiment of an antifreezing device 10 for a hermetic cooling tower 1 according to the present invention.

  The antifreezing device 10 for the hermetic cooling tower 1 is connected to the cooling water pump 4 in the cooling water circuit C1 via the switching valves V1 to V4, and in the present embodiment, the bypass circuit 11 that also bypasses the load 3 together. The antifreezing pump 12 is disposed in the bypass 11 and the antifreezing circuit C3 for circulating the cooling water through the heat exchanger 2 by the antifreezing pump 12 is configured.

  The switching valve V1 and the switching valve V2 are disposed between the heat exchanger 2 and the load 3, and the heat exchanger 2 is disposed between the switching valve V3 and the switching valve V4. Yes.

Further, an antifreezing pump 12 is disposed between the switching valve V3 and the switching valve V4.
Since the antifreezing pump 12 only needs to have a capacity that allows the cooling water to circulate through the antifreezing circuit C3, a small pump can be used.

  In the normal operation of the closed cooling tower 1, the switching valves V1 and V2 are opened, the switching valves V3 and V4 are closed, and the cooling water circuit C1 and the spray water circuit C2 are configured, and the cooling water pump 4 and the spray water pump 5 are operated to cool the load 3 serving as a heat source in the coolant circuit C1 while cooling the heat exchanger 2 with spray water.

  On the other hand, when the operation of the closed cooling tower 1 is stopped in winter when the outside air temperature is low, the switching valves V3 and V4 are opened and the switching valves V1 and V2 are closed so that only the freeze prevention circuit C3 is configured.

As a result, the cooling water can be circulated to the heat exchanger 2 only by operating the small antifreezing pump 12, and even if the operation of the closed cooling tower 1 is stopped in the winter when the outside air temperature is low. The heat exchanger 2 is frozen and does not break.
Further, since the cooling water does not come into contact with the sprayed water in the sprayed water circuit C2, no contamination is caused by the contact with the sprayed water.

By the way, in the said Example, although the switching valves V1-V4 are arrange | positioned, the flow of water is interrupted | blocked by stopping the driving | operation of the cooling water pump 4 and the antifreezing pump 12, for example. When the pump is used, the switching valves V1 to V4 are omitted as shown in FIG. 3 because the operation and stop of the cooling water pump 4 and the freeze prevention pump 12 perform the functions of the switching valves V1 to V4. can do.
In addition, the other structure and effect | action of this Example are the same as that of the said Example.

Further, in each of the above embodiments, the bypass 3 also bypasses the load 3 together with the cooling water pump 4 in the cooling water circuit C1, but for example, as shown in FIG. The bypass circuit 11 can be formed so as to bypass only the cooling water pump 4 in C1, and the switching valves V1 and V2 can be provided.
In addition, when using a pump of a type in which the flow of water is cut off by stopping the operation of the cooling water pump 4 and the freeze prevention pump 12, the operation and stop of the cooling water pump 4 and the freeze prevention pump 12 are switched. Since the functions of the valves V1 to V4 are fulfilled, the switching valves V1 to V4 can be omitted as in the embodiment shown in FIG.
In addition, the other structure and effect | action of this Example are the same as that of the said Example.

  As described above, the antifreezing device for the hermetic cooling tower of the present invention has been described based on the embodiments thereof, but the present invention is not limited to the configurations described in the above embodiments, and does not depart from the spirit thereof. The configuration can be changed as appropriate.

The freeze prevention device for a closed cooling tower of the present invention has a low energy cost for operation of the freeze prevention circuit even during operation of the freeze prevention circuit when the operation of the closed cooling tower is stopped. Since it has a characteristic that the cooling water is not contaminated by the contact, it can be suitably used for a hermetic cooling tower whose operation is often stopped in winter when the outside air temperature is low.
In addition to the new hermetic cooling tower, the application object can be applied to the existing hermetic cooling tower by attaching a freeze prevention circuit.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic explanatory drawing at the time of the normal operation which shows one Example of the freezing prevention apparatus of the hermetic cooling tower of this invention. It is a schematic explanatory drawing at the time of the freeze prevention operation | movement of the freeze prevention apparatus of the same enclosed cooling tower. It is a schematic explanatory drawing which shows another Example of the closed type cooling tower of this invention. It is a schematic explanatory drawing which shows another Example of the closed type cooling tower of this invention. It is the schematic explanatory drawing at the time of the normal operation which shows the conventional freezing prevention apparatus of the enclosed cooling tower. It is a schematic explanatory drawing at the time of the freeze prevention operation | movement of the freeze prevention apparatus of the same enclosed cooling tower.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Sealing type cooling tower 2 Heat exchanger 3 Load 4 Cooling water pump 5 Spraying water pump 10 Antifreezing device 11 Detour circuit 12 Antifreezing pump 13 Fan C1 Cooling water circuit C2 Sprinkling water block C3 Antifreezing circuit V1 Switching valve V2 switching Valve V3 switching valve V4 switching valve

Claims (1)

  A cooling water circuit in which cooling water circulates between the heat exchanger and the load by the cooling water pump and a spray water circuit in which the spray water for cooling the heat exchanger by the spray water pump circulates. In an anti-freezing device in a closed cooling tower that circulates cooling water when the operation is stopped to prevent the heat exchanger from freezing, a detour that bypasses the cooling water pump in the cooling water circuit is formed and frozen in the detour An anti-freezing device for a hermetic cooling tower, wherein an anti-freezing circuit is provided, and an anti-freezing circuit is configured to circulate cooling water to the heat exchanger by the anti-freezing pump.

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