Cooling water system with online automatic filtering device

Abstract

The utility model discloses a cooling water system with an on-line automatic filtering device, which comprises a circulating water tank, a circulating water pump, a water chilling unit and a heat exchanger which are sequentially communicated end to end through pipelines, the circulating water tank is communicated with a water source through a water replenishing pipe, and the on-line automatic filtering device comprises a filtering pump. The filter pump inlet is communicated with the circulating water tank through a filter pipeline, the filter pump outlet is communicated with the security filter inlet through a filter pipeline, and the security filter outlet is communicated with the circulating water tank through a filter pipeline; a turbidity online detector is arranged in the circulating water tank, the turbidity online detector is electrically connected with the signal input end of the PLC, and the signal output end of the PLC is electrically connected with the filter pump. The turbidity of the cooling water system is controlled through the on-line automatic filtering device, stable operation of the circulating cooling water system is achieved, the problems of overheating of a heat exchanger, low heat exchange efficiency and deterioration of water quality caused by too high turbidity are avoided, and the maintenance and operation cost is reduced.

Description

Technical Field

[0001] The utility model relates to the field of chemical production equipment, in particular to a cooling water system with an online automatic filtering device. Background Art

[0002] In the chemical production process, the industrial cooling water system is a comprehensive system involving water source treatment, refrigeration and temperature reduction, circulating cooling, water quality control, and reflux treatment, designed to provide stable and efficient cooling services for industrial production. Currently, a common cooling water system is to set up a water circulation tank, then introduce industrial water into the water circulation tank. A circulating water pump is installed at the outlet of the water circulation tank. The circulating water pump transports the water to the chiller. The chiller includes core components such as the evaporator, compressor, condenser, and expansion valve. The refrigerant circulation transfers heat from the water, cooling the water temperature to the set temperature. The cooled cooling water is then pumped to various equipment or processes that require cooling, such as heat exchangers, reactors, and air conditioning systems. During this process, the cooling water absorbs heat generated by the equipment, causing its own temperature to rise.

[0003] During operation, in order to prevent scaling, corrosion and microbial growth, an online water treatment system is usually installed in the circulating cooling water system, including the addition of chemical agents (such as corrosion inhibitors, scale inhibitors, bactericides, etc.) for chemical treatment, as well as regular drainage, water replenishment and replacement of fresh water to maintain water quality. However, long-term operation may cause problems such as heat exchanger leakage. Once the chemicals in the heat exchanger leak into the cooling water system, especially the leakage of acidic substances, suspended matter such as rust will enter the cooling water system, causing the turbidity of the cooling water system to increase. However, it is difficult to solve the problem of high water turbidity by using the above chemical agents. High cooling water turbidity will lead to the following problems: (1) Cooling water with high turbidity will form a cover and obstruction on the surface of the heat exchanger due to suspended particles, reducing the heat transfer efficiency of the heat exchanger, making it impossible for the heat exchanger to dissipate heat effectively, resulting in overheating of the heat exchanger and a decrease in heat exchange efficiency. In severe cases, it may also damage the heat exchanger; (2) The suspended particles in the cooling water contain corrosive ions. As the turbidity increases, these ions are more likely to adhere to the surface of the heat exchanger, further aggravating the corrosion process of the metal parts of the heat exchanger; (3) The long-term accumulation of suspended particles will cause blockage of cooling system pipes, filters, etc., affecting the smooth flow of water, increasing the system pressure drop, and in severe cases, causing the entire cooling system to fail; (4) High turbidity water will provide more attachment surfaces and nutrient sources for microorganisms, thereby promoting the reproduction and growth of microbial communities in the system, forming biofilms, affecting heat transfer efficiency and causing water quality to deteriorate; (5) Due to a series of problems caused by high turbidity, more frequent cleaning, maintenance and replacement of equipment are required, increasing maintenance and operating costs. Utility Model Content

[0004] The utility model provides a cooling water system with an online automatic filtering device, which aims to solve the problem that when chemical leakage occurs in the cooling water system, suspended matter enters the cooling water system, which increases the turbidity of the cooling water system, not only leading to low heat exchange efficiency but also damaging the heat exchange equipment.

[0005] To achieve its purpose, the utility model adopts the following technical solutions:

[0006] A cooling water system with an online automatic filtering device includes a circulating water tank, a circulating water pump, a chiller and a heat exchanger connected end to end through pipelines. The circulating water tank is connected to a water source through a water supply pipe. The online automatic filtering device includes a filter pump, the filter pump inlet is connected to the circulating water tank through a filter pipeline, the filter pump outlet is connected to the safety filter inlet through the filter pipeline, and the safety filter outlet is connected to the circulating water tank through the filter pipeline; an online turbidity detector is provided in the circulating water tank, the online turbidity detector is electrically connected to the signal input end of a PLC programmable controller, and the signal output end of the PLC programmable controller is electrically connected to the filter pump.

[0007] Furthermore, there are two security filters, which are arranged in parallel.

[0008] Furthermore, a first pressure gauge is provided at the inlet of the safety filter, and a second pressure gauge is provided at the outlet.

[0009] Furthermore, the flow rate of the filter pump is 20% of the hourly circulating water volume in the circulating water tank.

[0010] Furthermore, the flow rate of a single security filter is 10% of the hourly circulating water volume in the circulating water tank.

[0011] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0012] 1. The cooling water system provided by the utility model controls the turbidity of the cooling water system through an online automatic filtration device, thereby achieving stable operation of the circulating cooling water system, avoiding problems such as overheating of the heat exchanger, low heat exchange efficiency and deterioration of water quality caused by excessive turbidity, and reducing maintenance and operating costs.

[0013] 2. In the cooling water system provided by the present invention, the online turbidity detector arranged in the circulating water tank is electrically connected to the signal input terminal of the PLC programmable controller, and the signal output terminal of the PLC programmable controller is electrically connected to the filter pump, thereby realizing the interlocking of automatic control instruments, which is practical and intelligent. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a schematic diagram of the cooling water system structure of the utility model;

[0015] In the figure: 1-circulating water tank; 2-pipeline; 3-circulating water pump; 4-chiller; 5-heat exchanger; 6-filtration pump; 7-filtration pipeline; 8-safety filter; 9-PLC programmable controller; 10-turbidity online detector; 11-water supply pipe; 12-first pressure gauge; 13-second pressure gauge. DETAILED DESCRIPTION

[0016] The present invention will be further described below with reference to the accompanying drawings:

[0017] like Figure 1 As shown, the utility model is a cooling water system with an online automatic filtering device, including a circulating water tank 1, a circulating water pump 3, a chiller 4 and a heat exchanger 5 connected end to end through a pipe 2. The circulating water tank 1 is connected to the primary water source through a water supply pipe 11. The amount of primary water added needs to ensure that the entire cooling water system establishes a stable circulation.

[0018] The online automatic filtration device includes a filter pump 6. The inlet of the filter pump 6 is connected to the circulating water tank 1 via a filtration pipe 7. The outlet of the filter pump 6 is connected to the inlets of two parallel safety filters 8 via the filtration pipe 7. The outlets of the safety filters 8 are connected to the circulating water tank 1 via the filtration pipe 7, achieving recirculating filtration. The inlet and outlet pipes of the two parallel safety filters 8 are each controlled by valves, and the two safety filters 8 operate in a single-unit (one active, one standby) mode. A first pressure gauge 12 is installed at the inlet of the safety filter 8, and a second pressure gauge 13 is installed at the outlet. This facilitates monitoring of the inlet and outlet pressure differential of the safety filter 8 during operation. Under normal operating conditions, the operating pressure differential is: the pressure of the first pressure gauge 12 minus the pressure of the second pressure gauge 13 < 0.1 MPa. If the pressure of the first pressure gauge 12 minus the pressure of the second pressure gauge 13 is greater than or equal to 0.1 MPa, it indicates that the filter element of the active safety filter 8 is clogged and needs to be replaced. In this case, the parallel standby safety filter 8 can be put into operation, and the membrane tube of the out-of-service safety filter 8 can be replaced. Among them, the flow rate of the filter pump 6 is 20% of the water circulating volume in the circulating water tank 1 per hour, and the flow rate of a single safety filter 8 is 10% of the water circulating volume in the circulating water tank 1 per hour.

[0019] The circulating water tank 1 is provided with an online turbidity detector 10. The online turbidity detector 10 must have light source emission, signal processing, and logical operation functions, and can accurately calculate the turbidity in the water. The numerical value needs to be displayed in NTU units. The online turbidity detector 10 is electrically connected to the signal input end of the PLC programmable controller 9, and the signal output end of the PLC programmable controller 9 is electrically connected to the filter pump 6 to realize the automatic control instrument interlock. The interlock logic is that when the online turbidity detector 10 displays ≥50NTU, the PLC programmable controller 9 interlocks and controls to start the filter pump 6. When the online turbidity detector 10 displays <50NTU, the PLC programmable controller 9 interlocks and controls to stop the filter pump 6. The PLC programmable controller 9 intelligently selects to start or exit.

[0020] During chemical production, when using a 5°C circulating cooling water system, industrial primary water is first added to circulating water tank 1. The 5°C circulating cooling water system is then activated to circulate, ensuring stable outlet pressure and flow at circulating water pump 3. Circulating water pump 3 then delivers water to chiller 4 for cooling. The cooled water, now at 5°C, then passes through heat exchanger 5 to remove heat from the chemical materials. After the heat is removed, the water flows through pipe 2 to circulating water tank 1, repeating the cycle.

[0021] At the same time, start the online automatic filtration device to filter. Open the inlet and outlet valves of filter pump 6 to prime the filter pump 6, and open its exhaust valve to exhaust all air from the pump casing. Open the inlet and outlet valves of one safety filter 8 in standby mode and close the inlet and outlet valves of the other backup safety filter 8. Check that the interlocking functions of the PLC 9, online turbidity meter 10, and filter pump 6 are normal before commissioning. During operation, if the pressure on the first pressure gauge 12 of the standby safety filter minus the pressure on the second pressure gauge 13 is ≥ 0.1 MPa, this indicates that the filter element of the active safety filter 8 is clogged and needs to be replaced. At this point, switch to the backup safety filter 8 and replace the membrane tube of the out-of-service safety filter 8. The online automatic filtration device ensures that the turbidity of the 5°C cooling water system is kept below 50 NTU online, ensuring stable operation of the 5°C circulating cooling water system. This prevents problems such as heat exchanger overheating, low heat exchange efficiency, and water quality deterioration caused by excessive turbidity, thereby reducing maintenance and operating costs.

Claims

1. A cooling water system with an online automatic filtering device, comprising a circulating water tank (1), a circulating water pump (3), a chiller (4) and a heat exchanger (5) connected end to end via a pipe (2), wherein the circulating water tank (1) is connected to a water source via a water supply pipe (11), and is characterized in that: The online automatic filtering device comprises a filter pump (6), the inlet of the filter pump (6) is connected to the circulating water tank (1) through a filter pipe (7), the outlet of the filter pump (6) is connected to the inlet of the safety filter (8) through the filter pipe (7), and the outlet of the safety filter (8) is connected to the circulating water tank (1) through the filter pipe (7); an online turbidity detector (10) is provided in the circulating water tank (1), the online turbidity detector (10) is electrically connected to the signal input end of the PLC programmable controller (9), and the signal output end of the PLC programmable controller (9) is electrically connected to the filter pump (6).

2. A cooling water system with an online automatic filtration device according to claim 1, characterized in that: There are two security filters (8) arranged in parallel.

3. A cooling water system with an online automatic filtration device according to claim 2, characterized in that: The security filter (8) is provided with a first pressure gauge (12) at the inlet and a second pressure gauge (13) at the outlet.

4. A cooling water system with an online automatic filtration device according to any one of claims 1 to 3, characterized in that: The flow rate of the filter pump (6) is 20% of the hourly circulating water volume in the circulating water tank (1).

5. A cooling water system with an online automatic filtration device according to any one of claims 1 to 3, characterized in that: The flow rate of a single security filter (8) is 10% of the hourly circulating water volume in the circulating water tank (1).

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