A self-cooling pump test device

Abstract

This invention relates to the field of pump testing technology, specifically a self-cooling pump testing device. The invention includes a pump under test and a high-level water tank connecting the inlet and outlet of the pump under test. A self-priming connector is also connected between the outlet of the pump under test and the high-level water tank. A first constricted tube inserted into the inlet end of the self-priming connector is installed at the outlet of the pump under test, and a second constricted tube connecting the outlet end of the self-priming connector to the high-level water tank is located at the outlet end. The invention also includes a low-level water tank, with the middle part of the self-priming connector connected to the low-level water tank via a suction pipe. Through a reasonable piping layout, this invention, without significantly increasing the operating cost of the pump testing device, allows the pump testing device to combine the self-feeding function of a high-level water tank with the slow heating advantage of a low-level water tank.

Description

Technical Field

[0001] This invention relates to the field of pump testing technology, specifically a self-cooling pump testing device. Background Technology

[0002] A pump testing apparatus is a key piece of equipment used to test, verify, and evaluate pump performance. The apparatus mainly consists of a water supply tank and a circulation pipeline connecting the water supply tank to the pump under test. The water supply tank can be installed in a high-position configuration above the inlet of the pump under test or in a low-position configuration below the inlet of the pump under test.

[0003] In the high-level installation of the water supply tank, the water in the tank can be backflowed into the pump under test, thus eliminating the need for a pre-pump or other self-priming device to feed water to the pump. However, due to limitations in construction space and cost, the water supply tank is often relatively small. This results in a rapid temperature rise of the test medium during testing of large pumps, necessitating additional cooling and heat exchange devices to lower its temperature, thereby increasing operating costs.

[0004] In the low-position installation method of the water supply tank, a large-volume water supply tank structure can be formed by excavating a water pool, which can avoid rapid heating of the water tank and significantly improve its self-heating performance. However, since ordinary pumps do not have self-priming capabilities, a pre-submersible pump needs to be added to the pump inlet to provide pre-priming water for the pump under test. This means that for one pump test, two pumps need to be running simultaneously, resulting in at least double the unnecessary energy waste.

[0005] Clearly, neither of the existing water tank installation schemes can achieve both low cost and high heat dissipation, and therefore a solution is urgently needed. Summary of the Invention

[0006] In order to avoid and overcome the technical problems existing in the prior art, the present invention provides a self-cooling pump testing device. Through reasonable pipeline layout, the pump testing device combines the self-feeding function of high-position water supply tank and the slow heating advantage of low-position water supply tank without increasing the operating cost of the pump testing device too much.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] A self-cooled pump testing apparatus includes a test pump and an elevated water tank connecting the inlet and outlet of the test pump. A self-priming connector is also connected between the outlet of the test pump and the elevated water tank. A first constriction tube inserted into the inlet end of the self-priming connector is installed at the outlet of the test pump, and a second constriction tube connecting the outlet end of the self-priming connector to the elevated water tank is provided. The apparatus also includes a low-level water tank, and the middle part of the self-priming connector is connected to the low-level water tank through a suction pipe.

[0009] As a further aspect of the present invention: the equivalent diameters of the first and second necked tubes are adjustable, wherein the equivalent diameter of the first necked tube is adjusted according to the following formula:

[0010] ;

[0011] In the formula, The equivalent diameter of the first constricted tube is in mm;

[0012] The density of the test medium is expressed in kg / m³. 3 ;

[0013] The flow rate of the pump under test, in m³ / s. 3 / s;

[0014] The outlet pressure of the pump under test is expressed in Pa.

[0015] This represents the atmospheric pressure above the liquid surface in the low-level water tank, expressed in Pa.

[0016] This is the acceleration due to gravity, expressed in m / s².

[0017] This refers to the liquid level in the low-level water tank, in meters (m).

[0018] The flow rate of the suction pipe is expressed in meters (m³). 3 / s;

[0019] This is the diameter of the suction pipe, in meters (m).

[0020] This is the length of the suction pipe, in meters (m).

[0021] is the coefficient of friction of the fluid flowing in the suction pipe, which is dimensionless;

[0022] The equivalent diameter of the second constricted tube is adjusted according to the following formula:

[0023] ;

[0024] In the formula, This is the equivalent diameter of the second constricted tube, in mm;

[0025] c These are empirical coefficients, dimensionless.

[0026] yThe ratio coefficient between the flow rate of the suction pipe and the flow rate of the pump under test is dimensionless.

[0027] As a further embodiment of the present invention: an overflow pipe connecting the high-level water tank to the low-level water pool is installed on the upper part of the high-level water tank.

[0028] As a further aspect of the present invention: the high-level water tank is connected to the inlet of the pump under test through an inlet pipe, and a first control valve is installed on the inlet pipe.

[0029] As a further aspect of the present invention: a first pressure sensor is installed on the water inlet pipe near the inlet of the pump under test.

[0030] As a further embodiment of the present invention: the outlet of the tested pump is connected to the first constricted pipe through a drain pipe, and a second control valve is installed on the drain pipe.

[0031] As a further aspect of the present invention, a second pressure sensor is installed on the drain pipe near the outlet of the tested pump.

[0032] As a further aspect of the present invention, a flow meter is installed on the drain pipe.

[0033] Compared with the prior art, the beneficial effects of the present invention are:

[0034] 1. This application retains the structural layout of the high-level water tank and also provides a low-level water pool. During the circulation of the test medium between the high-level water tank and the pump under test, the self-priming connector at the outlet of the pump under test generates suction, which automatically draws the low-temperature test medium from the low-level water pool into the self-priming connector. The test medium in the low-level water pool mixes with the test medium discharged from the outlet of the pump under test, thereby reducing the temperature of the test medium finally sent to the high-level water tank. As a result, no additional cooling mechanism is required during the test, and no additional energy consumption is generated during the test.

[0035] 2. The equivalent diameters of the first and second necked tubes are adjustable. By adjusting these equivalent diameters, the suction flow rate of the suction pipe can be adjusted. By increasing or decreasing the suction flow rate of the suction pipe, the mixing ratio of the high-speed test medium discharged into the self-priming connector through the first necked tube and the low-speed test medium drawn into the suction pipe changes, thereby adjusting the cooling effect of the test medium discharged into the self-priming connector by the pump under test.

[0036] In addition, this application also provides an algorithm for adjusting the equivalent diameter of the first and second constricted tubes, so as to accurately adjust the equivalent diameter of the first and second constricted tubes according to the required mixing ratio of the mixed flow, so that the ratio between the high-speed test medium discharged into the self-priming connector by the first constricted tube and the low-speed test medium sucked in by the suction pipe in the mixed flow reaches the expected ratio, thereby providing technical support for adjusting the temperature of the mixed flow. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of the structure of the present invention.

[0038] In the diagram: 10, low-level water tank; 20, high-level water tank; 30, pump under test; 40, inlet pipe; 50, drain pipe; 51, first constriction pipe; 60, suction pipe; 70, self-priming connector; 71, second constriction pipe; 80, overflow pipe. Detailed Implementation

[0039] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0040] For ease of understanding, the specific structure and operation of the present invention will be further described below with reference to the accompanying drawings:

[0041] The specific structure of this invention is as follows: Figure 1As shown, its main structure includes a test pump 30 and a high-level water tank 20 connecting the inlet and outlet of the test pump 30. A self-priming connector 70 is also connected between the outlet of the test pump 30 and the high-level water tank 20. A first constriction tube 51 inserted into the inlet end of the self-priming connector 70 is installed at the outlet of the test pump 30. A second constriction tube 71 connecting the outlet end of the self-priming connector 70 to the high-level water tank 20 is also provided. It also includes a low-level water tank 10, and the middle part of the self-priming connector 70 is connected to the low-level water tank 10 through a suction pipe 60. This application retains the structural arrangement of the high-level water tank 20. The test medium in the high-level water tank 20 is automatically supplied to the test pump 30 under the action of gravity, thus eliminating the need to set up a pre-pump to continuously supply the test medium to the test pump 30 during the test. In addition, this application also includes a low-level water tank 10. During the circulation of the test medium between the high-level water tank 20 and the test pump 30, the self-priming connector 70 at the outlet of the test pump 30 generates suction, thereby automatically drawing the low-temperature test medium from the low-level water tank 10 into the self-priming connector 70. The test medium in the low-level water tank 10 is mixed with the test medium discharged from the outlet of the test pump 30, thereby reducing the temperature of the test medium finally sent into the high-level water tank 20. Thus, during the test, there is no need to operate an additional cooling mechanism, and therefore no additional energy consumption is generated during the test.

[0042] The self-priming principle of the self-priming connector 70 is as follows: Since the inlet end of the self-priming connector 70 is connected to the outlet of the pump under test 30 through the first constriction tube 51, the flow area of ​​the test medium at the first constriction tube 51 is obviously much smaller than the flow area of ​​the liquid at the outlet of the pump under test 30. Therefore, the flow velocity of the test medium delivered to the first constriction tube 51 will increase. As pressure energy is converted into kinetic energy, according to the principle of energy conservation, the pressure in the inner chamber of the self-priming connector 70 will decrease. When the pressure in the inner chamber of the self-priming connector 70 drops below atmospheric pressure, under the action of negative pressure, a negative pressure suction force is generated on the test medium in the low-level water tank 10 through the suction pipe 60, thereby realizing the self-priming function of the test medium in the low-level water tank 10. A second constriction tube 71 is provided at the outlet end of the self-priming connector 70. The high-speed test medium discharged into the self-priming connector 70 by the first constriction tube 51 and the low-speed test medium sucked in by the suction pipe 60 will mix into a mixed flow in the inner cavity of the self-priming connector 70. The mixed flow still flows through the first constriction tube 51 at a certain flow rate, and then converts pressure energy into kinetic energy. According to the principle of energy conservation, the subsequent pressure will gradually decrease, keeping the pressure in the inner cavity of the self-priming connector 70 lower than the pressure of the suction pipe 60.

[0043] Based on the above, such as Figure 1As shown, since the test medium in the low-level water tank 10 is mixed and then sent to the high-level water tank 20, the liquid level of the test medium in the high-level water tank 20 will gradually increase during the test. This application has an overflow pipe 80 connected to the low-level water tank 10 installed at the top of the high-level water tank 20. When the water level in the high-level water tank 20 increases above the overflow pipe 80, the test medium in the high-level water tank 20 can flow back to the low-level water tank 10 through the overflow pipe 80, and the large space of the low-level water tank 10 is used for heat dissipation.

[0044] In addition, such as Figure 1 As shown, the high-level water tank 20 is connected to the inlet of the test pump 30 through the inlet pipe 40, and a first control valve is installed on the inlet pipe 40 for connecting and disconnecting the inlet of the test pump 30 from the high-level water tank 20 so as to replace the test pump 30 with a new one for testing; at the same time, it can also be used to control the flow rate of the high-level water tank 20 into the inlet of the test pump 30.

[0045] Furthermore, a first pressure sensor is installed on the inlet pipe 40 near the inlet of the test pump 30 to obtain the pressure value at the inlet of the test pump 30.

[0046] Based on the above, such as Figure 1 As shown, the outlet of the test pump 30 is connected to the first constricted pipe 51 through the drain pipe 50. A second control valve is installed on the drain pipe 50, which is used to connect and disconnect the outlet of the test pump 30 from the high-level water tank 20 so as to replace the test pump 30 with a new one for testing; at the same time, it can also be used to control the flow rate of the outlet of the test pump 30.

[0047] In addition, a second pressure sensor is installed on the drain pipe 50 near the outlet of the pump under test 30, and a flow meter is installed on the drain pipe 50, which are used to obtain the pressure and flow rate at the outlet of the pump under test 30, respectively.

[0048] Based on the above, the equivalent diameters of the first constriction tube 51 and the second constriction tube 71 are adjustable. By adjusting these equivalent diameters, the suction flow rate of the suction pipe 60 can be adjusted. By increasing or decreasing the suction flow rate of the suction pipe 60, the mixing ratio of the high-speed test medium discharged by the test pump 30 into the self-priming connector 70 through the first constriction tube 51 and the low-speed test medium sucked in by the suction pipe 60 changes, thereby adjusting the cooling effect of the test medium discharged by the test pump 30 into the self-priming connector 70.

[0049] Specifically, this application also provides an algorithm for adjusting the equivalent diameter of the first constriction tube 51 and the second constriction tube 71, so as to accurately adjust the equivalent diameter of the first constriction tube 51 and the second constriction tube 71 according to the required mixing ratio of the mixed flow, so that the ratio between the high-speed test medium discharged into the self-priming connector 70 by the first constriction tube 51 and the low-speed test medium sucked in by the suction pipe 60 in the mixed flow reaches the expected ratio, thereby providing technical support for adjusting the temperature of the mixed flow.

[0050] Specifically, the equivalent diameter of the first constricted tube 51 is adjusted according to the following formula:

[0051] ;

[0052] In the formula, The equivalent diameter of the first constricted tube 51 is in mm;

[0053] The density of the test medium is expressed in kg / m³. 3 ;

[0054] The flow rate of the tested pump 30, in m³ / s. 3 / s;

[0055] The outlet pressure of the tested pump 30 is expressed in Pa.

[0056] The atmospheric pressure at the liquid surface of the low-level water tank 10 is expressed in Pa.

[0057] This is the acceleration due to gravity, expressed in m / s².

[0058] The liquid level of the low-level water tank 10 is as follows: Since the area and volume of the low-level water tank 10 in this application are much larger than those of the high-level water tank 20, the liquid level of the low-level water tank 10 is almost constant during the circulation of the medium. The unit is m.

[0059] The flow rate of the suction pipe is 60 m³ / h. 3 / s;

[0060] The diameter of the 60mm suction pipe is in meters (m).

[0061] The length of the suction pipe is 60 mm;

[0062] is the coefficient of friction of the fluid flowing through the suction pipe 60, which is dimensionless;

[0063] The equivalent diameter of the second constricted tube (71) is adjusted according to the following formula:

[0064] ;

[0065] In the formula, The equivalent diameter of the second constricted tube 71 is in mm;

[0066] c This is an empirical coefficient, dimensionless. The empirical coefficient is introduced to take into account the mixing loss and flow non-uniformity in actual design, and is taken as 1-1.3.

[0067] y The ratio coefficient between the flow rate of the set suction pipe 60 and the flow rate of the tested pump 30 is dimensionless.

[0068] I. The specific derivative logic of the equivalent diameter adjustment formula for the first necked tube 51 mentioned above is as follows:

[0069] (1) Write the equation for the cross-section of the suction pipe 60.

[0070] According to the principle of conservation of energy, applying Bernoulli's equation to the upper end of the suction pipe 60, we can obtain:

[0071] (1);

[0072] In the formula, The atmospheric pressure at the liquid surface of the low-level water tank 10 is expressed in Pa.

[0073] The pressure at the upper end of the suction pipe 60 is measured in Pa.

[0074] The density of the test medium is expressed in kg / m³. 3 ;

[0075] The acceleration due to gravity is expressed in m / s², and is taken as 9.81.

[0076] The liquid level in the low-level water tank 10 is in meters (m).

[0077] The length of the suction pipe is 60 mm;

[0078] The suction pipe has a nominal diameter of 60 mm, in meters.

[0079] The velocity of the test medium within the 60mm suction pipe is expressed in m / s.

[0080] is the coefficient of friction of the fluid flowing through the suction pipe 60, which is dimensionless;

[0081] (2);

[0082] The suction pipe has a flow rate of 60 m³ / h. 3 / s;

[0083] We can obtain:

[0084] (3);

[0085] From equations (1) to (3), we can solve for:

[0086] (4);

[0087] Since the flow design of the suction pipe 60 is generally turbulent, the friction coefficient of the turbulent fluid flowing in the suction pipe 60 is... for:

[0088] (5);

[0089] in, The drag coefficient is dimensionless. ;

[0090] The Reynolds number is dimensionless. ;

[0091] u The viscosity of the test medium is expressed in Pa·s.

[0092] (2) Write the equation for the cross section of the first constricted tube 51.

[0093] According to the principle of energy conservation, we can apply Bernoulli's equation to the first constricted tube section 51 to obtain:

[0094] (6);

[0095] In the formula, The outlet pressure of the tested pump 30 is given in Pa; the initial value can be determined by theoretical calculations based on the inherent characteristics of the pump before the test begins. , Is the traffic as Q The corresponding head was obtained through actual measurement after the start of the test;

[0096] The velocity at the outlet of the tested pump 30 is expressed in m / s. In actual design, the diameter of the outlet of the tested pump 30 is much larger than that of the first constriction tube 51; therefore, the velocity at the outlet of the tested pump 30 is... The flow velocity, which is much smaller than that at the outlet of the first constriction tube 51, is ignored in the calculations of this application. ;

[0097] The velocity at the outlet of the first constriction tube 51 is expressed in m / s.

[0098] Therefore, ignoring Then, equation (6) can be rearranged as:

[0099] (7);

[0100] This can then be further organized as follows:

[0101] (8);

[0102] The flow rate of the tested pump 30 is expressed in m³ / s. 3 / s;

[0103] The equivalent diameter of the first constricted tube 51 is in mm.

[0104] Combining formulas (6) to (8), we can obtain:

[0105] (9);

[0106] Substituting equation (4) into equation (9), we obtain the pipe diameter adjustment formula for the first necked tube 51 in this application:

[0107] ;

[0108] II. The specific formula for differentiating the equivalent diameter of the second necked tube 71 is as follows:

[0109] (1) Write the equation for the flow of the mixture in the self-priming pipe 70.

[0110] When the test medium is drawn into the chamber of the self-suction tube 70, the test medium delivered by the first constriction tube 51 exchanges momentum with the test medium drawn into the suction tube 60. According to the law of conservation of momentum, the following equation can be derived:

[0111] (10);

[0112] The discharge flow rate of the second constricted tube 71 is expressed in m³ / s. 3 / s;

[0113] The flow rate of the tested pump 30, in m³ / s. 3 / s;

[0114] The suction pipe has a flow rate of 60 m³ / h. 3 / s;

[0115] The discharge velocity of the second constriction tube 71 is expressed in m / s.

[0116] The velocity of the test medium within the 60mm suction pipe is expressed in m / s.

[0117] According to the principle of conservation of mass:

[0118] (11);

[0119] According to the requirements and The ratio between:

[0120] (12);

[0121] y For setting and The proportionality coefficient between them;

[0122] The liquid flow velocity within the suction pipe 60 is very small, and its magnitude is ignored in this application. ;

[0123] but:

[0124] (13);

[0125] b) According to the law of conservation of mass:

[0126] (14);

[0127] In the formula The area of ​​the second constricted tube 71 is in mm². 2 ;

[0128] Substituting equations (8), (11), and (12) into equation (14) yields:

[0129] (15);

[0130] Furthermore, due to:

[0131] (16);

[0132] Combining equations (15) and (16), the equivalent diameter of the second constricted tube 71 can be calculated. for:

[0133] (17);

[0134] In practical design, mixing losses and flow non-uniformity need to be considered, and empirical coefficients need to be introduced. c By taking a value of 1.3 to 1.0, the equivalent diameter of the actual second necked tube 71 required in this application is obtained. for:

[0135] (18).

[0136] During the practice, the conditions were divided into three groups:

[0137] The first group is when the test medium is water at 20℃, and the density of the test medium... 1000 kg / m 3 Atmospheric pressure at the liquid level of the low-level water tank 10 101325 Pa; gravitational acceleration The flow rate is 9.81 m / s²; the liquid level in the low-level water tank 10 is... The length is 3m; the suction pipe has a diameter of 60mm. It is 0.2m long; the suction pipe is 60mm long. The value is 3.5m. At this point, the viscosity of the test medium is... u Take 0.001 Pa·s as the friction coefficient. Based on the 60mm diameter of the suction pipe and the flow rate of the test medium within the suction pipe 60 Calculated The resistance coefficient is 40000, which gives the fluid resistance coefficient when flowing through the suction pipe 60. The outlet pressure of the tested pump 30 is 0.50. The flow rate of the tested pump 30 is set to 500,000 Pa. 100m 3 / h, water suction pipe flow rate 60 100m 3 / h.

[0138] Therefore, the calculation yields It is 34.62mm. The thickness is 69.24 mm, and the empirical coefficient c is taken as 1.05. It is 72.70mm.

[0139] According to the obtained equivalent diameter of the first constricted tube 51 The value of the equivalent diameter of the second constricted tube 71 Adjust the equivalent diameters of the first constriction tube 51 and the second constriction tube 71, and start the test apparatus. After stable operation, the measured flow rate of the tested pump 30 is 99.7 m³ / s. 3 / h, the flow rate of the 60mm suction pipe is 99.5m³ / h. 3 / h, with the expected flow rate fluctuation range all within 0.5m. 3 Within / h. Obviously, through the adjustment algorithm of the equivalent diameter of the first constriction tube 51 and the equivalent diameter of the second constriction tube 71 provided in this application, the ratio between the high-speed test medium discharged into the self-priming connector 70 by the first constriction tube 51 and the low-speed test medium sucked in by the suction pipe 60 in the mixed flow can reach the expected ratio, thereby providing technical support for adjusting the temperature of the mixed flow.

[0140] The second group involves water at 20.1℃, and the density of the test medium. 1000 kg / m 3 Atmospheric pressure at the liquid level of the low-level water tank 10 101325 Pa; gravitational acceleration The flow rate is 9.81 m / s²; the liquid level in the low-level water tank 10 is... The length is 3m; the suction pipe has a diameter of 60mm. It is 0.2m long; the suction pipe is 60mm long. The value is 3.5m. At this point, the viscosity of the test medium is... u Take 0.001 Pa·s as the friction coefficient. Based on the 60mm diameter of the suction pipe and the flow rate of the test medium within the suction pipe 60 The calculated value is 40038, from which the resistance coefficient of the fluid flowing in the suction pipe 60 can be obtained. The outlet pressure of the tested pump 30 is 0.50. The pressure is 500,000 Pa; the flow rate of the tested pump 30 is... 120m 3 / h; 60 flow rate for the suction pipe 120m 3 / h.

[0141] Therefore, the calculation yields It is 37.86mm. It is 75.71mm, empirical coefficient. c If we take 1.05, then It is 79.5mm.

[0142] According to the obtained equivalent diameter of the first constricted tube 51 The value of the equivalent diameter of the second constricted tube 71 Adjust the equivalent diameters of the first constriction tube 51 and the second constriction tube 71, and start the test apparatus. After stable operation, the measured flow rate of the tested pump 30 is 119.6 m³ / s. 3 / h, the flow rate of the 60mm suction pipe is 119.4m³ / h. 3 / h, with the expected flow rate fluctuation range all within 0.5m. 3 Within / h.

[0143] The third group involves water at 20.2℃, and the density of the test medium. 1000 kg / m 3 Atmospheric pressure at the liquid level of the low-level water tank 10 101325 Pa; gravitational acceleration The flow rate is 9.81 m / s²; the liquid level in the low-level water tank 10 is... The length is 3m; the suction pipe has a diameter of 60mm. It is 0.2m long; the suction pipe is 60mm long. The value is 3.5m. At this point, the viscosity of the test medium is... u Take 0.001 Pa·s as the friction coefficient. Based on the 60mm diameter of the suction pipe and the flow rate of the test medium within the suction pipe 60 The calculated value is 39888, from which the resistance coefficient of the fluid flowing in the suction pipe 60 can be obtained. The outlet pressure of the tested pump 30 is 0.50. The pressure is 500,000 Pa; the flow rate of the tested pump 30 is... 150m 3 / h; 60 flow rate for the suction pipe 150m 3 / h.

[0144] Therefore, the calculation yields It is 42.18mm. It is 84.37mm, empirical coefficient c If we take 1.05, then It is 88.59mm.

[0145] According to the obtained equivalent diameter of the first constricted tube 51 The value of the equivalent diameter of the second constricted tube 71 Adjust the equivalent diameters of the first constriction tube 51 and the second constriction tube 71, and start the test apparatus. After stable operation, the measured flow rate of the tested pump 30 was 149.8 m³ / s. 3 / h, the flow rate of the 60mm suction pipe is 149.6m³ / h. 3 / h, with the expected flow rate fluctuation range all within 0.5m. 3 Within / h.

[0146] Obviously, by using the adjustment algorithm for the equivalent diameter of the first constriction tube 51 and the equivalent diameter of the second constriction tube 71 provided in this application, the ratio between the high-speed test medium discharged into the self-priming connector 70 by the first constriction tube 51 and the low-speed test medium sucked in by the suction pipe 60 in the mixed flow can reach the expected ratio, thereby providing technical support for adjusting the temperature of the mixed flow.

[0147] Of course, those skilled in the art will recognize that the present invention is not limited to the details of the exemplary embodiments described above, but also includes the same or similar structures that can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0148] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

[0149] The technologies, shapes, and structures not described in detail in this invention are all known technologies.

Claims

1. A test method for a self-cooled pump test apparatus, comprising a test pump (30) and a high-level water tank (20) connected to the inlet and outlet of the test pump (30), characterized in that, A self-priming connector (70) is also connected between the outlet of the test pump (30) and the high-level water tank (20). The outlet of the test pump (30) is equipped with a first constriction tube (51) inserted into the inlet end of the self-priming connector (70). The outlet end of the self-priming connector (70) has a second constriction tube (71) that connects to the high-level water tank (20). It also includes a low-level water tank (10). The middle part of the self-priming connector (70) is connected to the low-level water tank (10) through a suction pipe (60). This reduces the temperature of the test medium that is finally sent into the high-level water tank (20). The equivalent diameters of the first constricted tube (51) and the second constricted tube (71) are adjustable, wherein the equivalent diameter of the first constricted tube (51) is adjusted according to the following formula: In the formula, D3 is the equivalent diameter of the first constricted tube (51), in mm; ρ is the density of the test medium, in kg / m³. 3 ; Q P The flow rate of the tested pump (30) is expressed in m³ / s. 3 / s; p2 is the outlet pressure of the tested pump (30), in Pa; p0 is the atmospheric pressure at the liquid surface of the low-level water tank (10), in Pa. g is the acceleration due to gravity, and its unit is m / s². 2 ; H0 is the liquid level height of the low-level water tank (10), in meters; Q X The flow rate of the suction pipe (60) is expressed in m³ / s. 3 / s; D s The diameter of the suction pipe (60) is in meters. L is the length of the suction pipe (60), in meters; k is the friction coefficient of the fluid flowing in the suction pipe (60), which is dimensionless; The equivalent diameter of the second constricted tube (71) is adjusted according to the following formula: In the formula, Q d The equivalent diameter of the second constricted tube (71) is in mm; c is an empirical coefficient, which is dimensionless; y is the proportionality coefficient between the flow rate of the set suction pipe (60) and the flow rate of the tested pump (30), which is dimensionless.

2. The test method for a self-cooling pump test device according to claim 1, characterized in that, An overflow pipe (80) connecting to the low-level water tank (10) is installed on the upper part of the high-level water tank (20).

3. The test method for a self-cooling pump test device according to claim 1, characterized in that, The high-level water tank (20) is connected to the inlet of the pump under test (30) through the water inlet pipe (40), and a first control valve is installed on the water inlet pipe (40).

4. The test method for a self-cooling pump test device according to claim 3, characterized in that, A first pressure sensor is installed on the inlet pipe (40) near the inlet of the test pump (30).

5. The test method for a self-cooling pump test apparatus according to claim 1, characterized in that, The outlet of the tested pump (30) is connected to the first constricted pipe (51) through a drain pipe (50), and a second control valve is installed on the drain pipe (50).

6. The test method for a self-cooling pump test apparatus according to claim 5, characterized in that, A second pressure sensor is installed on the drain pipe (50) near the outlet of the test pump (30).

7. The test method for a self-cooling pump test apparatus according to claim 5, characterized in that, A flow meter is installed on the drain pipe (50).

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