Closed cooling tower winter operation system based on PLC control

Abstract

The utility model relates to the technical field of non-ferrous metal metallurgy, and discloses a closed cooling tower winter operation system based on PLC (Programmable Logic Controller) control, which comprises high-temperature smelting equipment needing to be cooled, a closed cooling tower and a water tank, the internal circulation is composed of a water tank, a water pump M2, a water pump M3, a high-temperature equipment heat exchanger, an auxiliary water pump M4 and a cooling tower heat exchanger, the outer circulation is composed of a closed cooling tower, a water pump M1, spraying equipment and an auxiliary water pump M5. According to the closed cooling tower, circulating cooling of the high-temperature smelting equipment, the closed cooling tower and the water tank can be achieved through cooperation of all components, meanwhile, continuous operation of circulating water can be guaranteed through cooperation of the auxiliary water pump, and the anti-freezing problem of the closed cooling tower in winter operation can be effectively solved.

Description

Technical Field

[0001] The present invention relates to the field of automatic control, in particular to a design for the operation of multiple water pumps controlled by a PLC, and specifically to a design for the winter operation system of a closed cooling tower based on PLC control. Background Art

[0002] A closed cooling tower is a cooling device used for cooling industrial circulating water. Its greatest feature is the cooling of the internal and external double - circulation systems. The internal circulation completely isolates the air, there will be no evaporation and consumption of the circulating water, and no foreign objects will enter. The external circulation system ensures the cooling effect.

[0003] In the northern region, the winter temperature is usually below zero degrees Celsius, and the anti - freezing problem of the operation of closed cooling towers has become increasingly prominent. If not solved well, it may damage the heat exchange tubes or other components of the cooling tower. The closed cooling towers of metal smelting units in winter usually operate in some time periods. When operating, the circulating water cools the high - temperature furnace body, and the closed cooling tower can operate normally. During the shutdown stage, anti - freezing problems need to be considered. Usually adopted anti - freezing measures include draining water during shutdown, installing tracing cables, and operating without shutdown, etc. Utility Model Content

[0004] The purpose of the present utility model is to provide a winter operation system of a closed cooling tower based on PLC control to solve the problems raised in the above - mentioned background art.

[0005] In order to achieve the above purpose, the technical solution adopted by the present utility model is:

[0006] A winter operation system of a closed cooling tower based on PLC control includes a high - temperature melting equipment to be cooled, a closed cooling tower, and a water tank. The closed cooling tower is divided into two parts: an internal circulation and an external circulation. The internal circulation consists of a water tank, a main pump M2 and a standby pump M3, a high - temperature equipment heat exchanger, an auxiliary pump M4, and a cooling tower heat exchanger; the external circulation consists of a closed cooling tower, a pump M1, a spraying device, and an auxiliary pump M5.

[0007] The water tank is respectively connected to the pump M2, the pump M3, and the cooling tower heat exchanger.

[0008] The high - temperature equipment heat exchanger is respectively connected to the pump M2, the pump M3, and the cooling tower heat exchanger.

[0009] The spraying device and the cooling tower heat exchanger are both located inside the closed cooling tower, and the spraying device is located at the top inside the closed cooling tower.

[0010] The spraying device is connected to the bottom of the closed cooling tower through the pump M1 located outside the closed cooling tower.

[0011] The input end and the output end of the auxiliary water pump M5 are respectively connected to the bottom of the closed cooling tower through pipelines.

[0012] In summary, due to the adoption of the above technical solutions, the beneficial effects of the present utility model are as follows:

[0013] The present utility model can realize the circulating cooling of the high-temperature melting equipment, the closed cooling tower and the water tank by the cooperation of each component, and at the same time, with the cooperation of the auxiliary water pump, it can ensure the continuous operation of the circulating water, and can effectively solve the problem of anti-freezing during the winter operation of the closed cooling tower. Description of the Drawings

[0014] Figure 1 is a schematic structural diagram of the present utility model;

[0015] In the figure: high-temperature melting equipment 1, closed cooling tower 2, water tank 3, high-temperature equipment heat exchanger 4, cooling tower heat exchanger 5, spraying equipment 6. Detailed Embodiments

[0016] To make the objectives, technical solutions and advantages of the embodiments of the present utility model clearer, the technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Apparently, the described embodiments are some, but not all, of the embodiments of the present utility model. Generally, the components of the embodiments of the present utility model described and illustrated herein can be arranged and designed in various different configurations.

[0017] Therefore, the following detailed description of the embodiments of the present utility model provided in the drawings is not intended to limit the scope of the present utility model claimed, but merely represents selected embodiments of the present utility model. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts shall fall within the protection scope of the present utility model.

[0018] Such as Figure 1As shown in the figure, the utility model provides a winter operation system of a closed cooling tower based on PLC control, which includes a high-temperature smelting equipment 1 to be cooled, a closed cooling tower 2 and a water tank 3. The closed cooling tower is divided into two parts: an internal circulation and an external circulation. The internal circulation is composed of the water tank 3, a one-open-one-standby water pump M2 and water pump M3, a high-temperature equipment heat exchanger 4, an auxiliary water pump M4 (a small-power water pump) and a cooling tower heat exchanger 5. Both the water tank 3 and the high-temperature equipment heat exchanger 4 are respectively connected to the water pumps M2, M3 and the cooling tower heat exchanger 5. The external circulation is composed of the closed cooling tower 2, a water pump M1, a spraying device 6 and an auxiliary water pump M5 (a small-power water pump). Both the spraying device 6 and the cooling tower heat exchanger 5 are located inside the closed cooling tower 2. The spraying device 6 is located at the top inside the closed cooling tower 2. The input end of the spraying device 6 is connected to the bottom of the closed cooling tower 2 through a water pump M1 located outside the closed cooling tower 2. The input end and the output end of the auxiliary water pump M5 are respectively connected to the bottom of the closed cooling tower 2 through pipelines.

[0019] When the closed cooling tower is operating, the water tank 3 is filled with softened water for circulation. The circulating water is pressurized by the water pump M2 / water pump M3 from the water tank 3 and reaches the heat exchanger 4 of the high-temperature smelting equipment 1 to cool down the high-temperature smelting equipment 1. The circulating water gets heated up, and then the circulating water reaches the heat exchanger 5 of the closed cooling tower 2 (the water pump M4 stops). Under the cooling of the spraying device 6, the circulating water gets cooled down and then re-enters the water tank 3. The external circulating water of the closed cooling tower 2 is pressurized by the water pump M1 at the bottom pool of the cooling tower and enters the spraying device 6. After the circulating water is sprayed out, it is collected in the bottom pool of the cooling tower. When the high-temperature smelting equipment stops operating, the water pumps M2 / water pump M3 and the water pump M1 continue to operate for 1 hour, and the closed cooling tower continues to operate (to cool down the high-temperature smelting equipment and avoid long-term high temperature). After 1 hour, when the temperature of the high-temperature smelting equipment drops below 300 degrees Celsius, the closed cooling tower stops operating, the water pumps M2 / water pump M3 and the water pump M1 stop operating, and the auxiliary water pumps M4 and M5 start to operate to ensure the continuous operation of the internal and external circulating water to prevent the pipelines from freezing. After the start of work the next day, the high-temperature smelting equipment 1 starts to operate, the auxiliary water pumps M4 and M5 stop operating, the water pumps M2 / water pump M3 and the water pump M1 start to operate, and the closed cooling tower starts to work. During the winter production of the enterprise, it operates according to the above steps.

[0020] When the closed cooling tower is shut down for a long time, stop the operation of all equipment. In winter, it is necessary to drain the internal and external circulating water, or drain the external circulating water, and start the auxiliary water pump to ensure the continuous operation of the internal circulating water (the internal circulating water usually uses softened water).

Claims

1. A closed cooling tower winter operation system based on PLC control, characterized in that: It includes a high-temperature smelting device that needs to be cooled, a closed cooling tower, and a water tank. The closed cooling tower is divided into two parts: an internal circulation and an external circulation. The internal circulation consists of a water tank, a pump M2 and a pump M3 with one in use and one in reserve, a heat exchanger for high-temperature equipment, an auxiliary pump M4, and a heat exchanger for the cooling tower; the external circulation consists of a closed cooling tower, a pump M1, a spraying device, and an auxiliary pump M5.

2. The closed cooling tower winter operation system based on PLC control according to claim 1, characterized in that: The water tank is respectively connected to the pump M2, the pump M3, and the heat exchanger for the cooling tower.

3. The closed cooling tower winter operation system based on PLC control according to claim 1, characterized in that: The heat exchanger for high-temperature equipment is respectively connected to the pump M2, the pump M3, and the heat exchanger for the cooling tower.

4. A closed cooling tower winter operation system based on PLC control according to claim 1, characterized in that: The spraying device and the heat exchanger for the cooling tower are both located inside the closed cooling tower, and the spraying device is located at the inner top of the closed cooling tower.

5. A closed cooling tower winter operation system based on PLC control according to claim 1, characterized in that: The spraying device is connected to the bottom of the closed cooling tower through a pump M1 located outside the closed cooling tower.

6. The closed cooling tower winter operation system based on PLC control according to claim 1, characterized in that: The input end and the output end of the auxiliary pump M5 are respectively connected to the bottom of the closed cooling tower through pipelines.

Images