Abstract Through the experimental research on the characteristic parameters of single screw pump with the change of pump outlet pipe structure and suction pipe line structure, the relationship curves between the pump characteristic parameters and the outlet pressure and suction port vacuum degree are plotted. The experimental results show that changing the pump outlet pipeline structure to make the pump outlet pressure work within a certain range, the flow rate changes greatly, and the pump efficiency is higher, which can be used as a means to adjust the parameters of the pump. Pump adjustment parameters means. Keywords screw pump characteristic parameter adjustment parameter test The single scew pump characteristic parameter interrelationship curves with the pump outlet pressure and the suction vacuum was drawn after the test, the characteristic parameter was affected by the alteration of the outlet line and the suction line structure, was done. The test results have proven that the flow rate widely varied and the pump efficiency is high when the pump outlet line structure was altered and the outlet pressure was controlled in a special limit. Single-screw pump in the field of drilling, oil and oil and other aspects are being more widely used. Single screw pump work, often encountered problems regulating pump flow. For this type of volume pump, the flow rate adjustment methods commonly used in two ways. One is to change the speed of the rotor; the other is to change the discharge line or the suction line structure (usually to change the opening degree of the outlet valve or inlet valve). The main discussion of the second method. However, the change of pipeline structure will not only change the pressure and flow rate of the pump but also affect the energy consumption and efficiency of the pump. How to change the influence of the pump characteristics by changing the opening degree of the pump outlet valve and changing the valve opening degree of the pump inlet valve? Different? In response to these problems, we conducted the following two indoor tests. a) single screw pump flow, pump shaft torque, efficiency and other parameters with the outlet pressure changes in the characteristics of the test. b) single screw pump flow, pump shaft torque, efficiency and other parameters with the suction port changes in the characteristics of the vacuum test. 1 test methods and test results Figure 1 is a single screw pump characteristic test bench schematic. Test medium is clear water, room temperature. Test single screw pump structural parameters are as follows: screw diameter φ42mm, bushing lead 241mm, screw eccentricity 7.1mm, rated head 500mm. The test is divided into two situations, one is to fully open the suction port valve 12 to change the opening degree of the outlet valve 7, while testing the outlet pressure, flow, pump shaft torque, speed and suction port vacuum these parameters, the test data shown in Table 1 ; The second is the suction valve 12 is fully open, and then close the small discharge valve 7, until the outlet pressure increases to 7.0MPa, the discharge valve 7 open degree fixed, and then gradually close the suction inlet valve 12, the suction port vacuum The degree of increase, while testing the pump outlet pressure, pump shaft torque, pump shaft speed and discharge flow of these parameters, the test data in Table 2. Pump outlet pressure and suction vacuum degree respectively as the abscissa, the flow rate, shaft power, efficiency for the vertical axis of the pump characteristic curve, as shown in Figure 2, Figure 3. 1-motor 2 torque meter 3 bearing box 4 tee 5 single-screw pump 6 discharge pressure gauge 7 discharge valve 8 discharge line 9 metering tank 10 drain Valve 11 water tank 12 pump suction valve 13 suction line 14 suction port vacuum gauge Figure 1 single screw pump test bench working principle Table 1 changes the single screw pump outlet pressure characteristic test data test value Calculated Serial number Outlet pressure p o / MPa Suction port pressure p i / MPa Actual flow Q p / m 3 . d -1 Pump shaft torque M a / N. m Pump shaft speed n / r. min -1 Shaft power P a / kW Effective power P f / kW Volume efficiency η v / % Mechanical efficiency η m / % Pump efficiency η / % 1 0.1 0.076 101.05 86.36 251 2.27 0.028 97.26 1.27 1.23 2 2.0 0.076 100.20 128.79 250 3.37 2.230 96.81 68.39 66.20 3 2.2 0.078 100.15 136.82 250 3.58 2.460 96.76 71.01 68.80 4 3.2 0.079 99.20 184.97 250 4.84 3.580 95.85 77.25 74.02 5 3.8 0.079 98.81 213.63 250 5.59 4.260 95.47 79.74 76.26 6 5.3 0.082 94.00 288.15 249 7.51 5.680 91.17 82.91 75.63 7 7.2 0.086 86.50 379.04 245 9.72 7.120 85.29 85.91 73.25 8 8.4 0.096 76.20 424.49 237 10.53 7.320 77.67 89.55 69.53 Table 2 to change the single screw pump inlet vacuum characteristic test data test value Calculated Serial number Outlet pressure p o / MPa Suction port vacuum p hs / MPa Actual flow Q p / m 3 . d -1 Pump shaft torque M a / N. m Pump shaft speed n / r. min -1 Shaft power P a / kW Effective power P f / kW Volume efficiency η v / % Mechanical efficiency η m / % Pump efficiency η / % 1 7.00 0.0493 87.70 363.13 246 9.35 7.06 86.12 87.62 75.51 2 6.80 0.0293 86.00 362.82 247 9.38 6.74 84.41 85.08 71.86 3 6.50 0.0157 84.70 355.48 247 9.19 6.36 82.84 83.50 69.21 4 5.50 0.0092 72.10 298.85 250 7.82 4.58 69.67 84.10 58.56 5 4.40 0.0079 63.60 262.55 250 6.87 3.23 61.46 76.58 47.02 6 1.60 0.0039 31.30 134.52 250 3.52 0.58 30.24 54.31 16.48 p-N curve: outlet pressure and pump shaft power curve p-Q curve: outlet pressure and the actual flow curve p-η curve: outlet pressure and pump efficiency curve of Figure 2 to change the pump outlet pressure characteristics of the test Hs-N curve: vacuum and pump shaft power curve Hs-Q curve: vacuum and the actual flow curve Hs-η curve: vacuum and pump efficiency curve of Figure 3 to change the characteristics of the pump suction vacuum test 2 test analysis a) Single-screw pump theoretical flow, pump efficiency, volumetric efficiency and mechanical efficiency were calculated using the following formulas: η = 10 3 ΔpQp / (1.44Ma.n) (1) Qt = 1440 × 4eDTn (2) ηv = Qp / Qt (3) ηm = 10 3 QtΔp / (1.44Ma.n)             (4) Qt is the pump theoretical flow rate, m3 / d; η is the pump efficiency; ηv is the pump volumetric efficiency; ηm is the pump mechanical efficiency; Qp is the pump actual flow rate, m3 / d; Δp is the pump outlet and suction pressure differential, MPa; D for the screw section diameter, m; T for the bushing lead, m; Ma for the pump shaft torque, N. m; n is the pump shaft speed, r. min-1; e is the screw eccentricity, m. Based on the above formulas and the test data in Table 1 and Table 2, calculate the pump shaft power, effective power, pump efficiency, volumetric efficiency and mechanical efficiency under different operating conditions. The calculated values ​​are also shown in Table 1 and Table 2. b) From Table 1 and Figure 2, it can be seen that as the pump outlet pressure increases, the pump flow rate gradually decreases and the pump efficiency changes in a parabola shape with a highest efficiency point. Pump volume efficiency showed a decreasing trend, the mechanical efficiency showed an increasing trend (Figure 4), indicating that with the outlet pressure increases, the gap between the screw and bushing increases, the screw friction torque in the bush decreases when the friction torque , Resulting in increased mechanical efficiency; the same time, high-pressure liquid along the screw - bushing seal line cross-flow phenomenon intensified, resulting in reduced pump volumetric efficiency. As can be seen from the data in Table 1, when the outlet pressure changes in the range of 3.2 ~ 8.4MPa, the maximum difference in efficiency is 6.73%. Reference to the efficient working range of centrifugal pumps [1] , it can be considered that the scope of the screw pump is an efficient working range. Of course, the specific scope of efficient work should be based on the specific pump. c) Close the suction inlet valve is equivalent to artificially reduce the fullness of the pump, which will inevitably lead to reduced pump flow, pump inlet vacuum increased, which is also confirmed by the test. It can be seen from Table 2, Figure 3 and Figure 5 that the flow rate, shaft power, efficiency, volumetric efficiency and mechanical efficiency of the pump show a downward trend with the increase of the degree of vacuum in the suction inlet of the pump. However, when the degree of vacuum in the inlet changes between 0.1 ~ 0.015MPa, the above parameters show a downward trend, but the decline is smaller. This shows that within a certain range of changes in the degree of suction on the vacuum pump less impact on the characteristics of the pump; and once beyond this range, the parameters showed a straight downward trend, the working conditions of the pump greatly deteriorated. Therefore, when the pump inlet vacuum greater than a certain value, although the pump parameters can be greatly improved, but due to pump mechanical efficiency, volumetric efficiency and overall efficiency greatly reduced, it should be prohibited in this condition pump long term work. Figure 4 outlet pressure and mechanical efficiency, volumetric efficiency curve Figure 5 vacuum and mechanical efficiency, volumetric efficiency curve 3 Conclusion 1) Regardless of whether the pump outlet pipe structure is changed or the pump suction pipe structure is changed, the characteristics of the single screw pump will be affected to a certain extent. 2) to change the pump outlet valve opening degree, to achieve the purpose of changing the pump characteristic parameters within a certain range, and the pump has a higher work efficiency. 3) to change the single screw pump inlet valve opening degree, when the suction degree of vacuum is small, the pump characteristics of little change, and when the suction degree of vacuum is large, the working conditions of the pump deteriorated rapidly. Therefore, this method should not be used as a single screw pump to adjust the parameters of the means. Author: Daqing Petroleum Institute, Department of Mechanical Engineering, Heilongjiang Anda 151400 Daqing Petroleum Administration Building Company Daqing 163453, Heilongjiang Province 2 Daqing Petroleum Administration Eighth Oil Production Plant Daqing Heilongjiang 163514 references [1] Wanbang Lie, Li Jizhi. Oil Field Hydraulic Machinery. Beijing: Petroleum Industry Press, 1990.99 ~ 100 Abstract Through the experimental research on the characteristic parameters of single screw pump with the change of pump outlet pipe structure and suction pipe line structure, the relationship curves between the pump characteristic parameters and the outlet pressure and suction port vacuum degree are plotted. The experimental results show that changing the pump outlet pipeline structure to make the pump outlet pressure work within a certain range, the flow rate changes greatly, and the pump efficiency is higher, which can be used as a means to adjust the parameters of the pump. Pump adjustment parameters means. Keywords screw pump characteristic parameter adjustment parameter test The single scew pump characteristic parameter interrelationship curves with the pump outlet pressure and the suction vacuum was drawn after the test, the characteristic parameter was affected by the alteration of the outlet line and the suction line structure, was done. The test results have proven that the flow rate widely varied and the pump efficiency is high when the pump outlet line structure was altered and the outlet pressure was controlled in a special limit. Single-screw pump in the field of drilling, oil and oil and other aspects are being more widely used. Single screw pump work, often encountered problems regulating pump flow. For this type of volume pump, the flow rate adjustment methods commonly used in two ways. One is to change the speed of the rotor; the other is to change the discharge line or the suction line structure (usually to change the opening degree of the outlet valve or inlet valve). The main discussion of the second method. However, the change of pipeline structure will not only change the pressure and flow rate of the pump but also affect the energy consumption and efficiency of the pump. How to change the influence of the pump characteristics by changing the opening degree of the pump outlet valve and changing the valve opening degree of the pump inlet valve? Different? In response to these problems, we conducted the following two indoor tests. a) single screw pump flow, pump shaft torque, efficiency and other parameters with the outlet pressure changes in the characteristics of the test. b) single screw pump flow, pump shaft torque, efficiency and other parameters with the suction port changes in the characteristics of the vacuum test. 1 test methods and test results Figure 1 is a single screw pump characteristic test bench schematic. Test medium is clear water, room temperature. Test single screw pump structural parameters are as follows: screw diameter φ42mm, bushing lead 241mm, screw eccentricity 7.1mm, rated head 500mm. The test is divided into two situations, one is to fully open the suction port valve 12 to change the opening degree of the outlet valve 7, while testing the outlet pressure, flow, pump shaft torque, speed and suction port vacuum these parameters, the test data shown in Table 1 ; The second is the suction valve 12 is fully open, and then close the small discharge valve 7, until the outlet pressure increases to 7.0MPa, the discharge valve 7 open degree fixed, and then gradually close the suction inlet valve 12, the suction port vacuum The degree of increase, while testing the pump outlet pressure, pump shaft torque, pump shaft speed and discharge flow of these parameters, the test data in Table 2. Pump outlet pressure and suction vacuum degree respectively as the abscissa, the flow rate, shaft power, efficiency for the vertical axis of the pump characteristic curve, as shown in Figure 2, Figure 3. 1-motor 2 torque meter 3 bearing box 4 tee 5 single-screw pump 6 discharge pressure gauge 7 discharge valve 8 discharge line 9 metering tank 10 drain Valve 11 water tank 12 pump suction valve 13 suction line 14 suction port vacuum gauge Figure 1 single screw pump test bench working principle Table 1 changes the single screw pump outlet pressure characteristic test data test value Calculated Serial number Outlet pressure p o / MPa Suction port pressure p i / MPa Actual flow Q p / m 3 . d -1 Pump shaft torque M a / N. m Pump shaft speed n / r. min -1 Shaft power P a / kW Effective power P f / kW Volume efficiency η v / % Mechanical efficiency η m / % Pump efficiency η / % 1 0.1 0.076 101.05 86.36 251 2.27 0.028 97.26 1.27 1.23 2 2.0 0.076 100.20 128.79 250 3.37 2.230 96.81 68.39 66.20 3 2.2 0.078 100.15 136.82 250 3.58 2.460 96.76 71.01 68.80 4 3.2 0.079 99.20 184.97 250 4.84 3.580 95.85 77.25 74.02 5 3.8 0.079 98.81 213.63 250 5.59 4.260 95.47 79.74 76.26 6 5.3 0.082 94.00 288.15 249 7.51 5.680 91.17 82.91 75.63 7 7.2 0.086 86.50 379.04 245 9.72 7.120 85.29 85.91 73.25 8 8.4 0.096 76.20 424.49 237 10.53 7.320 77.67 89.55 69.53 Table 2 to change the single screw pump inlet vacuum characteristic test data test value Calculated Serial number Outlet pressure p o / MPa Suction port vacuum p hs / MPa Actual flow Q p / m 3 . d -1 Pump shaft torque M a / N. m Pump shaft speed n / r. min -1 Shaft power P a / kW Effective power P f / kW Volume efficiency η v / % Mechanical efficiency η m / % Pump efficiency η / % 1 7.00 0.0493 87.70 363.13 246 9.35 7.06 86.12 87.62 75.51 2 6.80 0.0293 86.00 362.82 247 9.38 6.74 84.41 85.08 71.86 3 6.50 0.0157 84.70 355.48 247 9.19 6.36 82.84 83.50 69.21 4 5.50 0.0092 72.10 298.85 250 7.82 4.58 69.67 84.10 58.56 5 4.40 0.0079 63.60 262.55 250 6.87 3.23 61.46 76.58 47.02 6 1.60 0.0039 31.30 134.52 250 3.52 0.58 30.24 54.31 16.48 p-N curve: outlet pressure and pump shaft power curve p-Q curve: outlet pressure and the actual flow curve p-η curve: outlet pressure and pump efficiency curve of Figure 2 to change the pump outlet pressure characteristics of the test Hs-N curve: vacuum and pump shaft power curve Hs-Q curve: vacuum and the actual flow curve Hs-η curve: vacuum and pump efficiency curve of Figure 3 to change the characteristics of the pump suction vacuum test 2 test analysis a) Single-screw pump theoretical flow, pump efficiency, volumetric efficiency and mechanical efficiency were calculated using the following formulas: η = 10 3 ΔpQp / (1.44Ma.n) (1) Qt = 1440 × 4eDTn (2) ηv = Qp / Qt (3) ηm = 10 3 QtΔp / (1.44Ma.n)             (4) Qt is the pump theoretical flow rate, m3 / d; η is the pump efficiency; ηv is the pump volumetric efficiency; ηm is the pump mechanical efficiency; Qp is the pump actual flow rate, m3 / d; Δp is the pump outlet and suction pressure differential, MPa; D for the screw section diameter, m; T for the bushing lead, m; Ma for the pump shaft torque, N. m; n is the pump shaft speed, r. min-1; e is the screw eccentricity, m. Based on the above formulas and the test data in Table 1 and Table 2, calculate the pump shaft power, effective power, pump efficiency, volumetric efficiency and mechanical efficiency under different operating conditions. The calculated values ​​are also shown in Table 1 and Table 2. b) From Table 1 and Figure 2, it can be seen that as the pump outlet pressure increases, the pump flow rate gradually decreases and the pump efficiency changes in a parabola shape with a highest efficiency point. Pump volume efficiency showed a decreasing trend, the mechanical efficiency showed an increasing trend (Figure 4), indicating that with the outlet pressure increases, the gap between the screw and bushing increases, the screw friction torque in the bush decreases when the friction torque , Resulting in increased mechanical efficiency; the same time, high-pressure liquid along the screw - bushing seal line cross-flow phenomenon intensified, resulting in reduced pump volumetric efficiency. As can be seen from the data in Table 1, when the outlet pressure changes in the range of 3.2 ~ 8.4MPa, the maximum difference in efficiency is 6.73%. Reference to the efficient working range of centrifugal pumps [1] , it can be considered that the scope of the screw pump is an efficient working range. Of course, the specific scope of efficient work should be based on the specific pump. c) Close the suction inlet valve is equivalent to artificially reduce the fullness of the pump, which will inevitably lead to reduced pump flow, pump inlet vacuum increased, which is also confirmed by the test. It can be seen from Table 2, Figure 3 and Figure 5 that the flow rate, shaft power, efficiency, volumetric efficiency and mechanical efficiency of the pump show a downward trend with the increase of the degree of vacuum in the suction inlet of the pump. However, when the degree of vacuum in the inlet changes between 0.1 ~ 0.015MPa, the above parameters show a downward trend, but the decline is smaller. This shows that within a certain range of changes in the degree of suction on the vacuum pump less impact on the characteristics of the pump; and once beyond this range, the parameters showed a straight downward trend, the working conditions of the pump greatly deteriorated. Therefore, when the pump inlet vacuum greater than a certain value, although the pump parameters can be greatly improved, but due to pump mechanical efficiency, volumetric efficiency and overall efficiency greatly reduced, it should be prohibited in this condition pump long term work. Figure 4 outlet pressure and mechanical efficiency, volumetric efficiency curve Figure 5 vacuum and mechanical efficiency, volumetric efficiency curve 3 Conclusion 1) Regardless of whether the pump outlet pipe structure is changed or the pump suction pipe structure is changed, the characteristics of the single screw pump will be affected to a certain extent. 2) to change the pump outlet valve opening degree, to achieve the purpose of changing the pump characteristic parameters within a certain range, and the pump has a higher work efficiency. 3) to change the single screw pump inlet valve opening degree, when the suction degree of vacuum is small, the pump characteristics of little change, and when the suction degree of vacuum is large, the working conditions of the pump deteriorated rapidly. Therefore, this method should not be used as a single screw pump to adjust the parameters of the means. Author: Daqing Petroleum Institute, Department of Mechanical Engineering, Heilongjiang Anda 151400 Daqing Petroleum Administration Building Company Daqing 163453, Heilongjiang Province 2 Daqing Petroleum Administration Eighth Oil Production Plant Daqing Heilongjiang 163514 references [1] Wanbang Lie, Li Jizhi. Oil Field Hydraulic Machinery. Beijing: Petroleum Industry Press, 1990.99 ~ 100 test value Calculated Serial number Outlet pressure p o / MPa Suction port pressure p i / MPa Actual flow Q p / m 3 . d -1 Pump shaft torque M a / N. m Pump shaft speed n / r. min -1 Shaft power P a / kW Effective power P f / kW Volume efficiency η v / % Mechanical efficiency η m / % Pump efficiency η / % 1 0.1 0.076 101.05 86.36 251 2.27 0.028 97.26 1.27 1.23 2 2.0 0.076 100.20 128.79 250 3.37 2.230 96.81 68.39 66.20 3 2.2 0.078 100.15 136.82 250 3.58 2.460 96.76 71.01 68.80 4 3.2 0.079 99.20 184.97 250 4.84 3.580 95.85 77.25 74.02 5 3.8 0.079 98.81 213.63 250 5.59 4.260 95.47 79.74 76.26 6 5.3 0.082 94.00 288.15 249 7.51 5.680 91.17 82.91 75.63 7 7.2 0.086 86.50 379.04 245 9.72 7.120 85.29 85.91 73.25 8 8.4 0.096 76.20 424.49 237 10.53 7.320 77.67 89.55 69.53 test value Calculated Serial number Outlet pressure p o / MPa Suction port vacuum p hs / MPa Actual flow Q p / m 3 . d -1 Pump shaft torque M a / N. m Pump shaft speed n / r. min -1 Shaft power P a / kW Effective power P f / kW Volume efficiency η v / % Mechanical efficiency η m / % Pump efficiency η / % 1 7.00 0.0493 87.70 363.13 246 9.35 7.06 86.12 87.62 75.51 2 6.80 0.0293 86.00 362.82 247 9.38 6.74 84.41 85.08 71.86 3 6.50 0.0157 84.70 355.48 247 9.19 6.36 82.84 83.50 69.21 4 5.50 0.0092 72.10 298.85 250 7.82 4.58 69.67 84.10 58.56 5 4.40 0.0079 63.60 262.55 250 6.87 3.23 61.46 76.58 47.02 6 1.60 0.0039 31.30 134.52 250 3.52 0.58 30.24 54.31 16.48