Output flow automatic regulating device, regulating method and centrifugal pump

Abstract

The present invention provides an output flow automatic regulating device, comprising a piston valve installed at one end at the pump outlet of a centrifugal pump body and a spray head installed at the other end of the piston valve, the piston valve comprising a piston rod, a piston and a cylinder, the spray head comprising a spray head inlet and a spray head outlet, a pressure regulating water pipe is provided at the spray head outlet, one end of the pressure regulating water pipe is connected to the pump inlet, and the pressure regulating water pipe is connected to the cylinder through a threaded water pipe, a spring is provided at the bottom of the cylinder, and the spring is placed directly below the piston; regulating valve 1 and pressure gauge 1 and regulating valve 2 and pressure gauge 2 are respectively provided on the pressure regulating water pipes on both sides of the threaded water pipe. In addition, the present invention provides a regulating method for the automatic regulating device and a centrifugal pump comprising the automatic regulating device, the service life of the pump is greatly extended, and according to experimental calculations, the centrifugal pump can operate continuously for 3 years.

Description

Technical Field

[0001] The invention relates to an output flow automatic regulating device, in particular to an output flow automatic regulating device of a mechanical centrifugal pump, a regulating method and a centrifugal pump with the regulating device. Background Art

[0002] The installation head of a centrifugal pump system refers to the energy required to transport a unit weight of liquid from the liquid surface of the suction tank to the liquid surface of the drainage tank. There are usually complex piping equipment between the suction tank and the drainage tank. There are pipeline losses during the transportation of the medium. There is a height difference between the liquid surface of the suction tank and the liquid surface of the drainage tank. There are differences in atmospheric pressure in different places and other factors make it difficult to accurately calculate the installation head. In order to meet the customer's use requirements, some margin is often given to the installation head, resulting in the calculated installation head Ha being greater than the actual installation head Ha1. Therefore, when designing and selecting the performance of the water pump, the pump head H1 ≥ Ha>Ha1. When the flow rate increases, the pump head decreases, the shaft power increases, and the operating efficiency decreases. When a centrifugal pump with a selected head of H1 is incorporated into the pipeline for operation, the actual pump head H2 can only operate at the actual installation head Ha1 point, from Figure 3 It can be seen that at this time, the flow rate of the pump will move from Q1 to Q2, the head H1 will move to H2, the efficiency will move from η1 to η2, and the shaft power will move from P1 to P2. Therefore, when the pump head is running at H2 (actual device head), the actual operating point delivery flow is greater than the design operating point, Q2>Q1, at this time the actual shaft power increases, P2>P1, the motor may be overloaded, and even cause the motor to overload, causing tripping, burning the motor and pump. At this time, the operating efficiency is low, η2<η1, the operating efficiency of the actual operating point is lower than the operating efficiency of the design operating point, resulting in large energy loss and low economic benefits. Summary of the invention

[0003] In order to solve the above-mentioned defects and shortcomings in the prior art, the present invention provides an output flow automatic adjustment device, an adjustment method and a centrifugal pump, which effectively solves the technical problem that the pump parts and the motor are damaged due to high flow operation of the pump caused by improper use or low actual head, and greatly extends the service life of the pump.

[0004] In order to solve the above technical problems, the present invention provides an output flow automatic regulating device, comprising a piston valve installed at one end at the pump outlet of a centrifugal pump body, and an injection head installed at the other end of the piston valve, the piston valve comprising a piston rod, a piston and a cylinder, the injection head comprising an injection head inlet and an injection head outlet, a pressure regulating water pipe is provided at the injection head outlet, one end of the pressure regulating water pipe is connected to the pump inlet, and the pressure regulating water pipe is connected to the cylinder through a threaded water pipe, a spring is provided at the bottom of the cylinder, and the spring is placed directly below the piston, wherein the initial tension of the spring is greater than the sum of the gravity of the piston and the piston rod; a regulating valve 1 and a pressure gauge 1 and a regulating valve 2 and a pressure gauge 2 are respectively provided on the pressure regulating water pipes on both sides of the threaded water pipe.

[0005] Furthermore, the piston valve and the pump outlet are fixedly connected by bolts.

[0006] Furthermore, the piston valve and the injection head are fixedly connected by bolts.

[0007] The present invention also provides a method for adjusting the above-mentioned mechanical centrifugal pump water outlet flow automatic regulating device, comprising the following steps:

[0008] Step 1: When the centrifugal pump is closed, the spring applies force to the piston, further driving the piston rod to move upward, thereby closing the injection head inlet;

[0009] Step 2: Open the injection head inlet: After the centrifugal pump is started, the liquid enters the pressure regulating water pipe from the pump inlet, and after the pressure is adjusted by the second pressure regulating valve, it enters the cylinder through the threaded water pipe, and pushes the piston to move downward and compresses the spring. During the downward movement of the piston, the piston rod is driven to move downward together, thereby opening the injection head inlet;

[0010] Step 3, water flow regulation: after the injection head inlet is opened, the output liquid passes through the pump outlet, the injection head inlet and the injection head outlet in sequence. A pressure regulating water pipe is provided at the injection head outlet. The liquid flows into the pressure regulating water pipe, is pressure-regulated by the pressure regulating valve 1, and then enters the cylinder through the threaded water pipe. The pressure regulating valve 2 is closed and the pressure of the pressure regulating valve 1 is adjusted, thereby changing the magnitude of the force applied by the liquid to the piston, and then changing the opening degree of the injection head inlet, thereby automatically adjusting the output flow of the pump;

[0011] Step 4: Reset the injection head inlet: After the centrifugal pump finishes working, the pressure at pressure regulating valve 1 and pressure regulating valve 2 is 0. Due to the elastic force of the spring itself, the piston moves upward to the top of the cylinder and drives the piston rod upward to close the injection head inlet. The adjustment device completes the reset to the step 1 state.

[0012] Furthermore, the specific calculation process of the output flow is as follows:

[0013] Calculate the pressure f on the piston: The pressure f on the piston = P / S, where S is the force area of ​​the piston and P is the pressure on the piston, which is equal to the pressure of the liquid flowing into the threaded water pipe:

[0014] When the centrifugal pump is started, the value P2 displayed on the pressure gauge 2 is the pressure of the liquid flowing into the threaded water pipe;

[0015] When the centrifugal pump runs stably, close the pressure regulating valve 2, and the pressure on the piston is equal to the value P1 displayed on the pressure gauge 1;

[0016] Calculate the spring force f 弹 : Spring force f 弹 = kΔX, ΔX is the compression of the spring, k is the elastic coefficient of the spring, which is a constant;

[0017] Since the pressure on the piston is equal to the elastic force f of the spring 弹 , that is, f=f 弹 , so the calculation formula for the spring compression ΔX is obtained:

[0018] ΔX=P / Sk;

[0019] The degree of opening of the injection head inlet is proportional to the compression amount ΔX of the spring.

[0020] Finally, the present invention also protects a centrifugal pump using the above-mentioned output flow automatic regulating device.

[0021] Beneficial technical effects achieved by the present invention: The output flow automatic regulating device provided by the present invention can make the pump operate within a set range by regulating the output flow by itself, thereby avoiding the large flow operation of the pump, thereby avoiding the problems of motor burnout and parts damage caused by the large flow, and greatly extending the service life of the pump. In addition, the present invention provides an adjustment method for the automatic regulating device, and the purpose of automatic adjustment can be achieved by simply adjusting the pressure at regulating valve one and regulating valve two according to actual requirements. Finally, the centrifugal pump provided by the present invention, which includes the automatic regulating device, has a greatly extended service life. According to experimental calculations, the centrifugal pump can operate continuously for 3 years. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a structural schematic diagram of the automatic water flow regulating device of the present invention when the centrifugal pump stops working;

[0023] Figure 2 It is a schematic structural diagram of the automatic water flow regulating device of the present invention when the centrifugal pump is in working state;

[0024] Figure 3 This is the characteristic curve of a centrifugal pump.

[0025] Among them, 1-pump inlet; 2-pressure regulating water pipe; 3-regulating valve 2; 4-pressure gauge 2; 5-threaded water pipe; 6-regulating valve 1; 7-pressure gauge 1; 8-injection inlet; 9-injection head outlet; 11-piston rod; 12-piston; 13-spring; 14-cylinder; 15-pump outlet; 16-centrifugal pump body. DETAILED DESCRIPTION

[0026] The present invention will be further described below in conjunction with specific examples. The following examples are only used to more clearly illustrate the technical solutions of the present invention, and are not intended to limit the scope of protection of the present invention.

[0027] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0028] like Figure 1-2 As shown, the present invention provides an automatic regulating device for the water outlet flow of a mechanical centrifugal pump, comprising a piston valve with one end mounted at the pump outlet of a centrifugal pump body, and a spray head mounted at the other end of the piston valve, wherein the piston valve comprises a piston rod, a piston and a cylinder, the spray head comprises a spray head inlet and a spray head outlet, a pressure regulating water pipe is arranged at the spray head outlet, one end of the pressure regulating water pipe is connected to the pump inlet, and the pressure regulating water pipe is connected to the cylinder through a threaded water pipe, a spring is arranged at the bottom of the cylinder, and the spring is placed directly below the piston, wherein the elastic force of the spring is greater than the sum of the weights of the piston and the piston rod, because, in order for the spring to push the piston and drive the piston rod to close the spray head inlet when the pump is stationary, the selected spring must have an initial tension greater than the sum of the weights of the piston and the piston rod, and must satisfy f 弹0 = (1.05-1.2) G 活塞+活塞杆 , f 弹0 Represents the initial tension of the spring itself, in N; G 活塞+活塞杆 =(m 活塞 +m 活塞杆 )g, G 活塞+活塞杆 Represents the sum of the weights of the piston and the piston rod, in N; m 活塞 Represents the weight of the piston, m 活塞杆 Represents the weight of the piston rod, in kg; g represents the local gravity acceleration, in m / s 2 ;

[0029] The pressure regulating water pipes on both sides of the threaded water pipe are respectively provided with regulating valve 1, pressure gauge 1 and regulating valve 2, pressure gauge 1 is used to display the pressure information of regulating valve 1, and pressure gauge 2 is used to display the pressure information of regulating valve 2. The pump can be operated within the set range, avoiding the large flow rate of the pump, thereby avoiding the problems of motor burning and parts damage caused by the large flow rate, and greatly extending the service life of the pump.

[0030] The piston valve and the pump outlet are fixedly connected by bolts; the piston valve and the injection head are fixedly connected by bolts, which is convenient for installation and disassembly.

[0031] The present invention also provides a method for adjusting the above-mentioned mechanical centrifugal pump water outlet flow automatic regulating device, comprising the following steps:

[0032] Step 1: When the centrifugal pump is closed, the spring applies force to the piston, further driving the piston rod to move upward, thereby closing the injection head inlet. Figure 1 As shown;

[0033] Step 2: Open the injection head inlet: After the centrifugal pump is started, the liquid enters the pressure regulating water pipe from the pump inlet, and after the pressure is adjusted by the pressure regulating valve 2, it enters the cylinder through the threaded water pipe, and pushes the piston to move downward and compresses the spring. During the downward movement of the piston, the piston rod is driven downward together, thereby opening the injection head inlet. Figure 2 As shown;

[0034] Step 3, water flow regulation: after the injection head inlet is opened, the output liquid passes through the pump outlet, injection head inlet and injection head outlet in sequence. A pressure regulating water pipe is provided at the injection head outlet. The liquid flows into the pressure regulating water pipe, and after being pressure-regulated by the pressure regulating valve 1, it enters the cylinder through the threaded water pipe. The pressure regulating valve 2 is closed and the pressure of the pressure regulating valve 1 is adjusted, thereby changing the magnitude of the force applied by the liquid to the piston, and then changing the opening degree of the injection head inlet, thereby automatically adjusting the output flow of the pump; the specific adjustment process is as follows:

[0035] Calculate the pressure f on the piston: The pressure f on the piston = P / S, where S is the force area of ​​the piston and P is the pressure on the piston, which is equal to the pressure of the liquid flowing into the threaded water pipe:

[0036] When the centrifugal pump is started, the value P2 displayed on the pressure gauge 2 is the pressure of the liquid flowing into the threaded water pipe;

[0037] When the centrifugal pump runs stably, close the pressure regulating valve 2, and the pressure on the piston is equal to the value P1 displayed on the pressure gauge 1;

[0038] Calculate the spring force f 弹 : Spring force f 弹 = kΔX, ΔX is the compression of the spring, k is the elastic coefficient of the spring, which is a constant;

[0039] Since the pressure on the piston is equal to the elastic force f of the spring 弹 , that is, f=f 弹 , so the calculation formula for the spring compression ΔX is obtained:

[0040] ΔX=P / Sk;

[0041] The degree of opening of the injection head inlet is proportional to the compression amount ΔX of the spring.

[0042] The degree of opening of the injection head inlet is proportional to the compression of the spring ΔX, that is, the compression of the spring determines the degree of opening of the injection head inlet. When the pump is running stably, close the pressure regulating valve 2. At this time, the compression of the spring ΔX=P1 / Sk. By adjusting the pressure of the control piston of the pressure regulating valve 1, the degree of opening of the injection head inlet can be adjusted, thereby changing the output flow of the regulating device.

[0043] Step 4: Reset the injection head inlet: After the centrifugal pump finishes working, the pressure at pressure regulating valve 1 and pressure regulating valve 2 is 0. Due to the elastic force of the spring itself, the piston moves upward to the top of the cylinder and drives the piston rod upward to close the injection head inlet. The regulating device completes the reset to the step 1 state.

[0044] Finally, the present invention also protects a centrifugal pump using the above output flow automatic regulating device. The service life of the pump is greatly extended. According to test calculations, the centrifugal pump can operate continuously for 3 years.

[0045] The present invention has been disclosed above with preferred embodiments, but they are not intended to limit the present invention. Any technical solutions obtained by adopting equivalent replacement or equivalent transformation solutions fall within the protection scope of the present invention.

Claims

1. An output flow automatic regulating device, characterized in that: It comprises a piston valve with one end installed at the pump outlet of a centrifugal pump body, and an injection head installed at the other end of the piston valve, the piston valve comprises a piston rod, a piston and a cylinder, the injection head comprises an injection head inlet and an injection head outlet, a pressure regulating water pipe is arranged at the injection head outlet, one end of the pressure regulating water pipe is connected to the pump inlet, and the pressure regulating water pipe is connected to the cylinder through a threaded water pipe, a spring is arranged at the bottom of the cylinder, and the spring is placed directly below the piston, wherein the initial tension of the spring is greater than the sum of the gravity of the piston and the piston rod; regulating valve 1 and pressure gauge 1 and regulating valve 2 and pressure gauge 2 are respectively arranged on the pressure regulating water pipes on both sides of the threaded water pipe; the piston valve and the pump outlet are fixedly connected by bolts; the piston valve and the injection head are fixedly connected by bolts.

2. The adjustment method of the output flow automatic adjustment device according to claim 1, characterized in that: The following steps are involved: Step 1: When the centrifugal pump is closed, since the initial tension of the spring is greater than the sum of the weights of the piston and the piston rod, the spring applies force to the piston, further driving the piston rod to move upward, thereby closing the injection head inlet; Step 2: Open the injection head inlet: After the centrifugal pump is started, the liquid enters the pressure regulating water pipe from the pump inlet, and after the pressure is adjusted by the second pressure regulating valve, it enters the cylinder through the threaded water pipe, and pushes the piston to move downward and compresses the spring. During the downward movement of the piston, the piston rod is driven to move downward together, thereby opening the injection head inlet; Step 3, output flow rate regulation: after the injection head inlet is opened, the output liquid passes through the pump outlet, the injection head inlet and the injection head outlet in sequence. A pressure regulating water pipe is provided at the injection head outlet. The liquid flows into the pressure regulating water pipe, is pressure-regulated by the pressure regulating valve 1, and then enters the cylinder through the threaded water pipe. The pressure regulating valve 2 is closed and the pressure of the pressure regulating valve 1 is adjusted, thereby changing the magnitude of the force applied by the liquid to the piston, and then changing the opening degree of the injection head inlet, thereby automatically adjusting the output flow rate of the pump; Step 4: Reset the injection head inlet: After the centrifugal pump finishes working, the pressure at pressure regulating valve 1 and pressure regulating valve 2 is 0. Due to the elastic force of the spring itself, the piston moves upward to the top of the cylinder and drives the piston rod upward to close the injection head inlet. The regulating device completes the reset to the step 1 state.

3. The adjustment method according to claim 2, characterized in that: The specific calculation process of output flow is as follows: Calculate the pressure f on the piston: The pressure f on the piston = P / S, where S is the force area of ​​the piston and P is the pressure on the piston, which is equal to the pressure of the liquid flowing into the threaded water pipe: When the centrifugal pump is started, the value P2 displayed on the pressure gauge 2 is the pressure of the liquid flowing into the threaded water pipe; When the centrifugal pump runs stably, close the pressure regulating valve 2, and the pressure on the piston is equal to the value P1 displayed on the pressure gauge 1; Calculate the spring force f 弹 : Spring force f 弹 = kΔX, ΔX is the compression of the spring, k is the elastic coefficient of the spring, which is a constant; Since the pressure on the piston is equal to the spring force f 弹 , that is, f=f 弹 , so the calculation formula for the spring compression ΔX is obtained: ΔX=P / Sk; The degree of opening of the injection head inlet is proportional to the compression amount ΔX of the spring.

4. A centrifugal pump having the output flow automatic regulating device according to claim 1.

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