Energy-saving pump machine device of cooling water system of steel rolling mill

Abstract

The utility model relates to a steel mill cooling water system energy-saving pump machine device which comprises a capsule air pressure tank, the input end of the capsule air pressure tank is connected with a filtering device, the input end of the filtering device is connected with an electric valve, the input end of the electric valve is connected with two sets of pump set water outlet main pipes, and the two sets of pump set water outlet main pipes are arranged in parallel. The pump set water outlet main pipe is connected with a main pipe pressure sensor, each pump set water outlet main pipe comprises a high-efficiency energy-saving water pump, the high-efficiency energy-saving water pump is connected with an electric valve, the input end of each high-efficiency energy-saving water pump is connected with a water inlet valve, and the high-efficiency energy-saving water pumps, the main pipe pressure sensor and the electric valve are connected to a control cabinet and are powered and controlled by the control cabinet. The main pipe pressure sensor detects the pressure of the water outlet main pipe of the pump set in real time and transmits the pressure data to the control cabinet; the device is efficient and energy-saving, can solve the problem of sudden pressure drop when a cooling water system of the rolling mill sprays water before the rolling mill is started, and improves the reliability of production water supply.

Description

[Technical field]

[0001] The utility model relates to the technical field of cooling water systems, in particular to an energy-saving pump device for a cooling water system in a steel rolling mill. [Background Technology]

[0002] Currently, the mill cooling water system in the plate mill workshop of a steel mill primarily provides cooling circulating water for equipment such as conveyor rollers and straighteners. After exchanging heat with the equipment, the water flows through a trench to a vortex well. This cooling water system also provides much of the spray water before the mills. This system, however, suffers from a range of issues, including high pressure fluctuations, severe cavitation, high vibration, and sharp noise.

[0003] The main reason is that the spray water in front of the rolling mill is used frequently and intermittently. When the valve in the spray water pipe in front of the rolling mill is opened, the flow rate increases significantly and the system pressure drops sharply. At this time, the water pump operates seriously out of working condition: the actual NPSH of the pump is too large, cavitation occurs, and the impeller is easily damaged. The water pump operates in the low efficiency range, with an efficiency of only 20%-50%, resulting in high ineffective energy consumption. The operating current increases sharply, exceeding the rated current of the motor, which is prone to motor failure and affecting production safety.

[0004] Therefore, this problem needs to be solved when carrying out energy-saving transformation of the user's rolling mill cooling water system. [Utility Model Content]

[0005] The purpose of this utility model is to solve the above-mentioned shortcomings and provide an energy-saving pump device for the cooling water system of a steel rolling mill, which is both highly efficient and energy-saving and can also solve the problem of sudden pressure drop in the cooling water system of the rolling mill when spraying water before starting the rolling mill, thereby improving the reliability of production water supply.

[0006] In order to achieve the above-mentioned purpose, an energy-saving pump device for the cooling water system of a steel rolling mill is designed, comprising a capsule air pressure tank 9, the input end of the capsule air pressure tank 9 is connected to a filter device 8 through a pipeline, the input end of the filter device 8 is connected to an electric valve 7, the input end of the electric valve 7 is connected to the pump group water outlet main through a pipeline, two groups of pump group water outlet mains are provided, and the two groups of pump group water outlet mains are arranged in parallel with each other, the pump group water outlet mains are connected to a main pressure sensor 6, each pump group water outlet main includes a high-efficiency energy-saving water pump 2, the high-efficiency energy-saving water pump 2 is respectively connected to the electric valve 7 through a line, the input end of each high-efficiency energy-saving water pump 2 is respectively connected to an inlet valve 1 through a pipeline, the inlet valve 1 is connected to the water outlet of the turbid ring cold water tank, the high-efficiency energy-saving water pump 2, the main pressure sensor 6, and the electric valve 7 are respectively connected to a control cabinet 10 through lines, and are powered and controlled by the control cabinet 10, the main pressure sensor 6 detects the pressure of the pump group water outlet main in real time and transmits the pressure data to the control cabinet 10.

[0007] Furthermore, each pump group water outlet main pipe is provided with a branch pressure gauge 3, a full-bore micro-stop return valve 4 and a water outlet valve 5. The input end of the branch pressure gauge 3 is connected to the high-efficiency energy-saving water pump 2, and the output end of the branch pressure gauge 3 is connected to the full-bore micro-stop return valve 4. The output end of the full-bore micro-stop return valve 4 is connected to the input end of the water outlet valve 5. The output end of the water outlet valve 5 is connected to the electric valve 7 through a pipeline. The full-bore micro-stop return valve 4 can achieve full-bore conveying of the medium, and the flow efficiency is higher. At the same time, the branch pressure gauge 3 ensures the stability of pressure and flow.

[0008] Furthermore, the filtering device 8 is composed of a left end flange 8-1, a shell 8-2, a stainless steel filter screen 8-3 and a right end flange 8-4. The left end flange 8-1 and the right end flange 8-4 are respectively installed on the left and right ends of the shell 8-2. The stainless steel filter screen 8-3 is welded to the inner wall of the shell 8-2. The left end of the stainless steel filter screen 8-3 is open and the right end of the stainless steel filter screen 8-3 is closed, so that it only plays the role of blocking large particles. When the pressure tank is filled with water, the large particles are blocked outside the pressure tank to protect the capsule from being damaged by the large particles. When the pressure tank is discharged from water, the large particles are carried away with the outlet water flow.

[0009] Furthermore, the left end flange 8-1 of the filter device 8 faces the electric valve 7, and the right end flange 8-4 of the filter device 8 faces the capsule air pressure tank 9, so that the filtering effect is better and it is more convenient and quick to connect with the electric valve 7 and the capsule air pressure tank 9.

[0010] Compared with the prior art, the utility model aims at the problem of energy-saving transformation of the pump system and provides a new pump device, which is not only highly efficient and energy-saving, but also can solve the problem of sudden pressure drop of the cooling water system of the rolling mill when the rolling mill sprays water before the rolling mill is turned on, thereby improving the reliability of production water supply; the pump device realizes that when the rolling mill sprays water, the pressure fluctuation amplitude is small and the current change amplitude is small, thereby improving the reliability of production water supply; in addition, at the moment of using the spray water, the pressure and current change smoothly, and the water pump runs stably, which saves energy and ensures production safety, and is worthy of promotion and application. [Brief Description of the Drawings]

[0011] Figure 1 It is a structural diagram of the utility model;

[0012] Figure 2 It is a structural diagram of the filter device of the utility model;

[0013] Figure 3 This is a pressure-time variation curve diagram before the improvement of the present invention;

[0014] Figure 4 This is a pressure-time variation curve diagram of the present utility model;

[0015] Figure 5 This is a current-time variation curve diagram before the improvement of the utility model;

[0016] Figure 6 It is a current-time variation curve diagram of the utility model;

[0017] In the figure: 1, water inlet valve 2, high-efficiency energy-saving water pump 3, branch pressure gauge 4, full-diameter micro-stop return valve 5, water outlet valve 6, main pipe pressure sensor 7, electric valve 8, filter device 9, capsule air pressure tank 10, control cabinet 8-1, left end flange 8-2, shell 8-3, stainless steel filter 8-4, right end flange. [Specific implementation method]

[0018] As attached Figure 1 As shown, the utility model provides a new pump device for energy-saving transformation of pump systems, specifically, an energy-saving pump device for cooling water system of steel rolling mill, including a capsule air pressure tank 9, the input end of the capsule air pressure tank 9 is connected to the filter device 8 through a pipeline, the input end of the filter device 8 is connected to the electric valve 7, the input end of the electric valve 7 is connected to the pump group water outlet main through a pipeline, the pump group water outlet main is provided with two groups, and the two groups of pump group water outlet mains are arranged in parallel with each other, the pump group water outlet main is connected to the main pressure sensor 6, each pump group water outlet main includes a high-efficiency energy-saving water pump 2, the high-efficiency energy-saving water pump 2 is connected to the electric valve 7 through a line, the input end of each high-efficiency energy-saving water pump 2 is connected to the water inlet valve 1 through a pipeline, the water inlet valve 1 is connected to the water outlet of the turbid ring cold water tank, the high-efficiency energy-saving water The pump 2, the main pipe pressure sensor 6, and the electric valve 7 are respectively connected to the control cabinet 10 through lines, and are powered and controlled by the control cabinet 10. The main pipe pressure sensor 6 detects the pressure of the pump group water outlet main in real time and transmits the pressure data to the control cabinet 10; wherein, each pump group water outlet main is provided with a branch pressure gauge 3, a full-bore micro-stop return valve 4 and a water outlet valve 5, the input end of the branch pressure gauge 3 is connected to the high-efficiency energy-saving water pump 2, the output end of the branch pressure gauge 3 is connected to the full-bore micro-stop return valve 4, the output end of the full-bore micro-stop return valve 4 is connected to the input end of the water outlet valve 5, and the output end of the water outlet valve 5 is respectively connected to the electric valve 7 through a pipeline. The full-bore micro-stop return valve 4 can achieve full-bore conveying of the medium, and the flow efficiency is higher. At the same time, the branch pressure gauge 3 ensures the stability of pressure and flow.

[0019] As attached Figure 2As shown, the filter device 8 consists of a left end flange 8-1, a shell 8-2, a stainless steel filter screen 8-3 and a right end flange 8-4. The left end flange 8-1 and the right end flange 8-4 are respectively installed on the left and right ends of the shell 8-2. The stainless steel filter screen 8-3 is welded to the inner wall of the shell 8-2. The left end of the stainless steel filter screen 8-3 is open and the right end of the stainless steel filter screen 8-3 is closed, so that it only plays the role of blocking large particles. When the pressure tank is filled with water, the large particles are blocked outside the pressure tank to protect the capsule from being damaged by large particles. When the pressure tank is discharged from the water, the large particles are carried away with the outlet water flow; the left end flange 8-1 of the filter device 8 faces the electric valve 7, and the right end flange 8-4 of the filter device 8 faces the capsule pressure tank 9, so that the filtering effect is better and it is more convenient and quick to connect with the electric valve 7 and the capsule pressure tank 9.

[0020] The present invention will be further described below with reference to the accompanying drawings and specific embodiments:

[0021] This energy-saving pump assembly primarily consists of an inlet valve 1, a high-efficiency, energy-saving water pump 2, a branch pressure gauge 3, a full-bore micro-stop valve 4, an outlet valve 5, a main pressure sensor 6, a motorized valve 7, a filter 8, a capsule air pressure tank 9, and a control cabinet 10. The high-efficiency, energy-saving water pump 2 is custom-made based on measured data to match the system's normal operating conditions. The capsule air pressure tank 9 is connected to the pump assembly main pipe via the motorized valve 7 and filter 8. The filter 8 consists of a left-end flange 8-1, a housing 8-2, a stainless steel filter screen 8-3, and a right-end flange 8-4. The stainless steel filter screen is welded to the inner wall of the housing, with the left side open and the right side sealed. The installation direction of the filter device 8 is that the left end flange 8-1 faces the water outlet pipe of the pump group, and the right end flange 8- faces the capsule pressure tank 9. It only serves to block large particles. When the pressure tank is filled with water, the large particles are blocked outside the pressure tank to protect the capsule from being damaged by large particles. When the pressure tank is discharged from the water, the large particles are carried away with the outlet water flow.

[0022] The high-efficiency, energy-saving water pump 2, main line pressure sensor 6, and electric valve 7 are all connected to a control cabinet 10, which supplies power and control to the system. The electric valve 7 is linked to the high-efficiency, energy-saving water pump 2. When any water pump starts, the electric valve 7 slowly opens, allowing water to flow into the pressure tank. This prevents damage to the capsule caused by a sudden pressure surge when the tank is empty (in certain special circumstances). When all water pumps are shut down, the electric valve 7 slowly closes. The main line pressure sensor 6 monitors the main line pressure in real time and transmits this data to the control cabinet 10. If the main line pressure falls below the set value while at least one pump is running, an alarm is triggered and a backup pump is automatically activated to maintain the main line pressure.

[0023] The present invention is described below by means of specific embodiments:

[0024] The roller cooling water system of a medium plate mill has two pumps, one for use and one for backup. When the spray water in front of the mill is not turned on, the actual operating flow is 160m 3 / h, main pipe pressure 0.7MPa, operating current 120A, operating power 70.5KW, system efficiency about 40.6%; when the spray water in front of the rolling mill is turned on, the actual operating flow is 450m 3 / h, main pipe pressure 0.3MPa, operating current 150A, operating power 88.1KW, system efficiency about 24.5%. Spray water lasts about 8 seconds, with an average interval of 2 minutes. This system has the problem of low system efficiency and high energy consumption, and has great potential for energy-saving transformation. However, it also has its own characteristics, see the attached for details. Figure 3 and attached Figure 5 The pressure-time curve and current-time curve of the equipment before improvement show that when the spray water is used, the pressure drops sharply and the current rises sharply, and the vibration and noise of the water pump increase significantly, affecting production safety. Analysis of the operating data shows that the increase in flow rate during the spray water opening period is approximately (450-160)×8 / 3600≈0.645m 3 .

[0025] According to the parameters of normal operation point, design and select high-efficiency energy-saving pump. Normal operation point flow rate 160m 3 / h, main pipe pressure 0.7MPa. The actual operating current of the high-efficiency energy-saving pump is 80A, the operating power is 46.8KW, the hourly power saving is 23.7KW, and the power saving rate is 33.6%. During the use of spray water, if the high-efficiency energy-saving pump does not cause cavitation vibration, check the performance curve of the high-efficiency energy-saving pump and ensure that the main pipe pressure is not less than 0.55MPa. At this time, the corresponding flow rate of the pump is 190m 3 / h. Additional flow rate required: 0.645-(190-160)×8 / 3600≈0.578m 3 The inflation pressure of the capsule air pressure tank is 0.4MPa, and the total volume V of the capsule air pressure tank is calculated according to the following formula:

[0026] V(1-(0.4+0.1) / (0.7+0.1))-V(1-(0.4+0.1) / (0.55+0.1))>0.578m 3 ;

[0027] V>4m 3 ;

[0028] Taking the coefficient of 1.1, V≥4.4m 3 , select a total volume greater than 4.4m 3 The capsule air pressure tank can ensure that the main pipe pressure is not less than 0.55MPa during the use of spray water.

[0029] The improved energy-saving pump device is shown in the attached Figure 4 and attached Figure 6 The pressure-time and current-time curves for the energy-saving pump device in the figure show gentle changes in pressure and current at the moment of water spraying, ensuring stable pump operation, saving energy while ensuring production safety. (The above parameters and calculations are based on existing technology in the field and are only used for comparison to demonstrate the effectiveness of the present invention.)

[0030] The contents not described in detail in this specification belong to the existing technology known to professional and technical personnel in this field. The standard parts used can be purchased from the market, and special-shaped parts can be customized according to the description in the specification and drawings. The specific connection methods of each part adopt mature conventional means such as bolts, rivets, welding, etc. in the existing technology. The machinery, parts and equipment all adopt conventional models in the existing technology, and the circuit connections adopt conventional connection methods in the existing technology, which will not be described in detail here.

[0031] The present invention is not limited to the above-mentioned embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be considered as equivalent replacement methods and are included in the scope of protection of the present invention.

Claims

1. An energy-saving pump device for a cooling water system in a steel rolling mill, characterized by: The invention comprises a capsule air pressure tank (9), wherein the input end of the capsule air pressure tank (9) is connected to a filter device (8) via a pipeline, the input end of the filter device (8) is connected to an electric valve (7), the input end of the electric valve (7) is connected to a pump group water outlet pipe via a pipeline, the pump group water outlet pipes are provided with two groups, and the two groups of pump group water outlet pipes are arranged in parallel with each other, the pump group water outlet pipes are connected to a pipe pressure sensor (6), and each pump group water outlet pipe includes a high-efficiency energy-saving water pump (2), the high-efficiency energy-saving water pump (2 ) are connected to the electric valve (7) through lines respectively, the input end of each high-efficiency energy-saving water pump (2) is connected to the water inlet valve (1) through a pipeline, the water inlet valve (1) is connected to the water outlet of the turbid ring cold water tank, the high-efficiency energy-saving water pump (2), the main pipe pressure sensor (6), and the electric valve (7) are connected to the control cabinet (10) through lines respectively, and are powered and controlled by the control cabinet (10), the main pipe pressure sensor (6) detects the pressure of the water outlet main pipe of the pump group in real time, and transmits the pressure data to the control cabinet (10).

2. The energy-saving pump device for the cooling water system of a steel rolling mill according to claim 1, characterized in that: Each pump group water outlet main pipe is provided with a branch pressure gauge (3), a full-diameter micro-stop return valve (4) and a water outlet valve (5); the input end of the branch pressure gauge (3) is connected to the high-efficiency energy-saving water pump (2); the output end of the branch pressure gauge (3) is connected to the full-diameter micro-stop return valve (4); the output end of the full-diameter micro-stop return valve (4) is connected to the input end of the water outlet valve (5); and the output end of the water outlet valve (5) is connected to the electric valve (7) through a pipeline.

3. The energy-saving pump device for the cooling water system of a steel rolling mill according to claim 1, characterized in that: The filtering device (8) is composed of a left end flange (8-1), a shell (8-2), a stainless steel filter screen (8-3) and a right end flange (8-4). The left end flange (8-1) and the right end flange (8-4) are respectively mounted on the left and right ends of the shell (8-2). The stainless steel filter screen (8-3) is welded to the inner wall of the shell (8-2). The left end of the stainless steel filter screen (8-3) is open, and the right end of the stainless steel filter screen (8-3) is closed.

4. The energy-saving pump device for the cooling water system of a steel rolling mill according to claim 1, characterized in that: The left end flange (8-1) of the filter device (8) faces the electric valve (7), and the right end flange (8-4) of the filter device (8) faces the capsule air pressure tank (9).

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