CN202937463U - Self-sucking height test table for high-suction self-sucking pump - Google Patents

Abstract

The utility model relates to a self-priming height test bench for a self-priming pump with a high suction range. The test bench includes a test pump (1), an adjustable frequency conversion booster pump (5) and an electric differential pressure reducing valve (9). An adjustable frequency conversion booster pump (5) is added to the pump return pipe to supplement the pressure head at the inlet of the injector of the jet device, and an electric differential pressure reducing valve (9) is added to increase the pressure drop at the pump inlet. The inlet of the adjustable frequency conversion booster pump (5) is connected to the outlet of the test pump return pipe (4), and the outlet is connected to the inlet of the injector of the jet device (7); the inlet of the electric differential pressure reducing valve (9) is connected to the jet device (7) ) The upper ends of the venturi tubes are connected, and the outlet is connected with the inlet of the test pump (1). According to the installation height to be simulated, determine the head of the adjustable frequency conversion booster pump (5) and the pressure difference at the inlet and outlet of the electric differential pressure reducing valve (9), and set them. The utility model features: without changing the actual installation height of the test bench, it can meet the requirements of various jet pump tests.

Description

A self-priming height test bench for high-suction self-priming pumps

technical field

The utility model relates to a self-priming height test bench for a self-priming pump with a high suction range. the

Background technique

The self-priming pump is a special kind of centrifugal pump, which means that it only needs to add a certain amount of water to the pump before starting for the first time, without filling the water inlet pipe with water. A type of water pump that enters the normal working state immediately after the gas is discharged. In addition to the hydraulic performance parameters of ordinary centrifugal pumps, such as flow, head, efficiency and other parameters, self-priming height and self-priming time are unique performance parameters of self-priming pumps, and are important indicators for evaluating self-priming performance of self-priming pumps. The self-priming height refers to the installation height from the liquid level to the center line of the pump inlet flange when the self-priming pump pumps up the liquid. In general, when no special device is installed at the pump inlet, the installation height of the pump is the atmospheric head height (10.33m) minus the vaporization pressure of the pump, the necessary NPSH and the loss of the inlet pipeline, so the general installation height does not exceed 9m. However, in practical applications, especially with the decline of groundwater level and surface water level, it is necessary to operate a pump with a height of more than 9m in many occasions, that is, a high-suction self-priming pump. At this time, special devices need to be added to the pump to achieve Greater self-priming height. Jet pump is the one of self-priming pump, and it is made up of centrifugal pump and jet flow device, relies on the vacuum that jet flow device causes at the nozzle place to realize self-priming. According to the needs, the self-priming installation height of the jet pump can be designed to reach more than 40m. the

The measurement of the self-priming height is generally to install the self-priming pump on a lift tower, and change the height from the lift tower to the pool. If the pump can successfully self-prime at this installation height, it means that the self-priming pump can reach this self-priming height. Therefore, it is necessary to build a lifting tower of a corresponding height to test the self-priming height of the pump. The self-priming pump lifting tower commonly used at present can generally reach a height of 8-9m to adapt to the self-priming performance test of ordinary self-priming pumps. But for jet pumps with higher self-priming height, adopting the above traditional method needs to spend a lot of manpower, material and financial resources to specially build a lifting platform of corresponding height or put the jet pump into a very deep well to test the self-priming height. At present, there are no lifting towers and deep wells of relevant heights in China to test the self-priming height of high-suction self-priming pumps. The self-priming height test of high-suction jet pumps is in a blank state, which affects the improvement of the hydraulic performance of the pump and the self-priming. Further development of pumps. the

The traditional test method and test bench layout are as follows:

The jet pump is composed of a centrifugal pump and a jet device. First, the centrifugal pump is installed at the design installation height, filled with water before starting, the outlet gate valve is closed, the motor is started, and the centrifugal pump starts to work. The water pressure in the return pipe begins to increase. Before the gate valve is opened, the water in the return pipe passes through the jet device, the water inlet pipe, and returns to the centrifugal pump to continue circulation. At this time, the bottom valve is closed. The outlet gate valve is gradually opened, and a small amount of water is discharged from the outlet. At this time, the water ejected by the nozzle in the jet device at high speed takes away the surrounding liquid, and the pressure around the nozzle drops. Under the action of atmospheric pressure, the bottom valve opens (the opening degree is affected by the opening degree of the outlet gate valve) and starts to absorb water. As the gate valve is gradually opened, the opening of the bottom valve will gradually increase. If the pump is normal at this installation height, the self-priming height is the pump installation height. the

Nowadays, the self-priming height of the jet pump can be designed to reach more than 40m. Obviously, the traditional test method needs to test the installation height of this kind of pump to be more than 40m. If you want to test a jet pump with a high self-priming height, you need to install it in a very high place or on a lifting tower, that is, a high installation height is required, which will inevitably require a lot of investment. the

Contents of the invention

The purpose of the utility model is to provide a self-priming height test platform for a self-priming pump with a high suction range, which can meet the test requirements of a self-priming pump with a relatively high self-priming height. Compared with the traditional self-priming pump self-priming height test bench, this test bench can measure the actual higher self-priming height at a smaller installation height. the

The technical scheme adopted by the utility model is as follows: the test bench includes a test pump (1), an adjustable frequency conversion booster pump (5) and an electric differential pressure reducing valve (9), and an adjustable frequency conversion valve is added to the pump return pipe. The booster pump (5) is used to supplement the pressure head at the inlet of the injector of the jet device, and the electric differential pressure reducing valve (9) is added to increase the pressure drop at the pump inlet. The inlet of the variable frequency booster pump (5) and the return pipe (4 ) outlet, the outlet is connected to the injector inlet of the jet device (7), the inlet of the electric differential pressure reducing valve (9) is connected to the upper end of the venturi tube of the jet device (7), and the outlet is connected to the inlet of the test pump (1) connected. the

Before the test, it is necessary to set the adjustable frequency conversion booster pump and the electric differential pressure reducing valve according to the designed installation height of the test pump to meet the requirements for testing a specific jet pump. the

In order to simulate the operating state of the self-priming pump at the actual self-priming height, the following formula is provided on the pump return pipe:

H _g ＝H _z +H′ _g +H _f1

That is, the head setting of the adjustable variable frequency booster pump has the following formula:

H _z =H _g -H' _g -H _f1

H _z : head produced by adjustable frequency conversion booster pump, unit m

H _g : design self-priming height of the test pump, unit m

H′ _g : the actual installation height of the test bench, unit m

H _f1 : hydraulic loss in the return pipe, unit m

Similarly, there is the following formula on the pump inlet pipe:

H _g ＝H _j +H′ _g +H _f2

The following formula is used for setting the electric differential pressure reducing valve:

H _j ＝H _g -H′ _g -H _f2

H _j : the pressure drop generated by the electric differential pressure reducing valve, unit m

H _g : design self-priming height of the test pump, unit m

H′ _g : installation height of the test bench, unit m

H _f2 : hydraulic loss in the inlet pipe, unit m

The utility model has the following characteristics: on the basis of the traditional self-priming pump performance test platform, an adjustable frequency conversion booster pump and an electric differential pressure reducing valve are added to realize the measurement of the self-priming height of the self-priming pump with high suction range. Without changing the actual installation height of the test pump, by setting the adjustable frequency conversion booster pump and the electric differential pressure reducing valve, various installation heights can be simulated, which can meet the needs of various jet pump tests without adding The new test bench equipment is put into use, and the testing process is simple and convenient. the

Description of drawings

Accompanying drawing 1 is the test bench schematic diagram of the present utility model. the

Detailed ways

The embodiments of the present utility model are described in detail below, and the present embodiment is implemented under the premise of the technical solution, and detailed implementation methods and specific implementation processes are provided, but the protection scope of the present utility model is not limited to the following implementation example. the

As shown in Figure 1, the test bench is mainly composed of a test pump 1 (including a jet device 7, a tee 2, a gate valve 3 and a bottom valve 6), an adjustable frequency conversion booster pump 5 and an electric differential pressure reducing valve 9, etc. . The main function of this test bench is to pressurize the return pipe and decompress the inlet pipe. The pressurization of the return pipe is realized by an adjustable frequency conversion booster pump 5 , and the decompression of the water inlet pipe is realized by an electric differential pressure reducing valve 9 . The inlet of the adjustable frequency conversion booster pump 5 is connected to the outlet of the pump return pipe 4, and the outlet is connected to the inlet of the injector of the jet device 7; Connect the test pump 1 inlet. the

Referring to the accompanying drawing 1, firstly, the test pump 1 is fixed on the test bench, the installation height is H' _g , the installation height H _g to be simulated, and the head Hz of the adjustable frequency conversion booster pump 5 is determined.

The following formula is used to set the 5 lift _Hz of the adjustable frequency conversion booster pump:

H _z =H _g -H' _g -H _f1

H _z : head generated by adjustable frequency conversion booster pump 5, unit m

H _g : design self-priming height of test pump 1, unit m

H′ _g : the actual installation height of the test bench, unit m

H _f1 : hydraulic loss in the return pipe, unit m

Secondly, according to the installation height H _g to be simulated, the pressure difference at the inlet and outlet of the electric differential pressure reducing valve 9 needs to be reduced, and the pressure drop H _j generated by the electric differential pressure reducing valve 9 is set.

The following formula is used to set the pressure drop H _j of the electric differential pressure reducing valve 9:

H _j ＝H _g -H′ _g -H _f2

H _j : the pressure drop generated by the electric differential pressure reducing valve 9, unit m

H _g : design self-priming height of test pump 1, unit m

H′ _g : installation height of the test bench, unit m

H _f2 : hydraulic loss in the inlet pipe, unit m

Finally, after setting, the injection pump can be tested. When the self-priming pump can self-prime successfully, it means that the pump has passed the test, otherwise it means that the test has failed. the

The utility model has the following characteristics: on the basis of the traditional self-priming pump performance test bench, an adjustable frequency conversion booster pump 5 and an electric differential pressure reducing valve 9 are added to realize the measurement of the self-priming height of the self-priming pump with high suction range. Without changing the actual installation height of the test pump, by setting the adjustable frequency conversion booster pump 5 and the electric differential pressure reducing valve 9, various installation heights can be simulated to meet the needs of various jet pump tests, and There is no need to increase the investment in test bench equipment, and the test process is simple and convenient. the

In this embodiment, the test pump model is JP-505, and the design performance parameters of the tested pump are as follows:

The flow rate is 10m ³ /h, the head is 80m, the power is 1.8Kw, the suction diameter is 25mm, and the suction lift H _g =23m.

The installation height of the pump is set as H′ _g = 3m. In order to meet the suction requirement of 23m, it is necessary to use the adjustable frequency conversion booster pump 5 to increase the water head of 20m in the return pipe 4, and use the electric differential pressure reducing valve 9 to increase the water head in the inlet pipe 4. Reduce the water head by 20m in the water pipe 8 (pipeline losses H _f1 and H _f2 are omitted, and the actual situation shall prevail during measurement).

According to the formula (1), the 5 head of the adjustable frequency booster pump _Hz is set to 20m.

According to the formula (2), the pressure drop H _j of the electric differential pressure reducing valve 9 is set to 20m, that is, the pressure difference between the inlet and outlet should be set to 0.2Mpa.

That is to say, the test bench under this setting can measure the JP-505 deep suction pump with a suction distance of 23m. the

Claims (1)

1. high priming stroke self priming pump suction lift test bench, it is characterized in that: test stand comprises test pump (1), adjustable freq uency conversion supercharging pump (5) and electronic Fixed differential reducing valve (9), increase adjustable freq uency conversion supercharging pump (5) to replenish fluidic device sparger inlet pressure head on the blowback water pipe, increase electronic Fixed differential reducing valve (9) to increase the pressure drop of pump inlet, adjustable freq uency conversion supercharging pump (5) import is connected with return pipe (4) outlet, outlet is connected with fluidic device (7) sparger import, electronic Fixed differential reducing valve (9) import and fluidic device (7) literary composition are told inner pipe upper end and are connected, outlet is connected with the import of test pump (1).