RU2016265C1 - Method for operating pump-ejector system - Google Patents

Abstract

FIELD: hydraulic engineering. SUBSTANCE: gas-fluid mixture is fed to the inlet of the system. The mixture is separated. The separated fluid is pumped and the separated gas is ejected. Part of the mixture is bled and fed together with the flow of the separated gas for ejection of the pumped separated fluid. A particular characteristic relation for various flow rates of the bled mixture is preliminary plotted. EFFECT: improved reliability. 3 cl, 2 dwg, 1 tbl

Description

 The invention relates to inkjet technology and may find application in the oil and gas industry, thermal power and other sectors of the economy.

 A known method of operation of a pump-ejector system, including the separation of the gas-liquid mixture, pumping the separated liquid and directing one part of it to the consumer, and the other to eject the separated gas, followed by the supply of the gas-liquid mixture to the system inlet.

 The disadvantage of this method is the low efficiency of ejection.

 Closest to the claimed technical solution is a method of operating a pump-ejector system, comprising supplying a gas-liquid mixture to the inlet of the system, separating the mixture, pumping the separated liquid, and ejecting the separated gas therewith.

 The disadvantage of this method is the low system performance.

 The purpose of the invention is to increase the system performance by improving energy exchange between interacting flows, optimizing the operation of the pump-ejector system and providing a mode of maximum system performance.

This is achieved by the fact that part of the gas-liquid mixture supplied to the system inlet is taken together with the separated gas stream for ejection by the injected separated liquid. The optimization of the operation of the pump-ejector system is achieved by the fact that previously for various costs of the selected gas-liquid mixture, a characteristic dependence is built
Q _c = f (Q _ws ^otb ) where Q _c is the system capacity for the gas-liquid mixture, l / s;
Q _LLL ^sel - gazozhidkosnoy mixture withdrawn consumption in l / s, at which the system operation mode is set in the characteristic curve of the upper branch band limited value of the maximum flow rate withdrawn liquid mixture.

Determine the optimal flowrate withdrawn liquid mixture (Q ^dep _{GLM) opt,} corresponding to the maximum system performance, and the withdrawn liquid mixture flow is maintained in the range of 0,52-1,5 (Q ^dep _{GLM) opt.}

In FIG. 1 shows a diagram of a device for implementing the proposed method; in FIG. 2 - characteristic dependence of Q _c = f (Q _ghs ^otb ).

 A device for implementing the method of operation of the pump-ejector system comprises an inlet pipe 1 of a gas-liquid mixture, a separator 2 with a liquid 3 and gas 4 lines, a pump 5, an ejector 6, a line 7 for supplying a gas-liquid mixture to a consumer, a line 8 for selecting a part of the gas-liquid mixture 8 with an adjustable gate valve 9 .

 The method of operation of the pump-ejector system is as follows.

 The gas-liquid mixture is fed to the inlet of the system through the inlet pipe 1. In the separator 2, the mixture is separated into gas and liquid. The liquid through the liquid line 3 enters the pump 5 and is pumped into the active nozzle of the ejector 6. The separated gas enters through the gas line 4 into the receiving chamber of the ejector 6 and is ejected by the liquid pumped by the pump 5. A part of the gas-liquid mixture entering the system inlet via pipeline 1 is taken off and sent via line 8 to ejection with the injected separated liquid together with the separated gas stream. The flow rate of the selected gas-liquid mixture can be changed using an adjustable gate valve 9. After the ejector 6, the gas-liquid mixture with increased pressure is sent to the consumer through line 7.

 The supply of a gas-liquid mixture to the flow of ejected gas improves the energy exchange between the injected working fluid and the ejected medium, which increases the performance of the pump-ejector system.

To optimize the operation of the pump-ejector system for any previously withdrawn liquid mixture costs build intrinsic dependence Q _c = f (Q _GLM ^sel), in which the system operation mode is set in the range of the upper characteristic curve branch limited value of the maximum flow rate withdrawn liquid mixture.

 For example, when testing the method for the case of pumping out the air-water mixture with a surfactant - disolvan 4411 at the laboratory bench in MING them. I. M. Gubkin, the following results were obtained, presented in the table.

Characteristic dependence of Q _c = f (Q _GLM ^sel) is constructed from experimental points. This dependence has two branches - the upper (solid line in Fig. 2) and the lower (dashed line in Fig. 2). From the analysis of the characteristic dependence it follows that at the beginning, when the adjustable gate valve is opened, both the flow rate of the selected gas-liquid mixture and the system performance increase. Then the system performance goes through a maximum and with a further increase in the flow rate of the selected gas-liquid mixture decreases. At the subsequent opening of the adjustable gate valve, the dependence Q _l = f (Q _ghs ^otb ) bends to the left, passing from the upper branch to the lower one. The boundary between the branches depending on the characteristic determined by the maximum flow withdrawn liquid mixture (Q _GLM ^sel) max (see. Fig. 2). Thus, the further opening of the adjustable gate valve leads to a decrease in both the flow rate of the selected gas-liquid mixture and the performance of the system.

More favorable operating modes are implemented in the area of the upper branch; therefore, the pump-ejector systems are operated in the zone of the upper branch of the characteristic dependence Q _c = f (Q _GFG ^otb ). If the operating mode of the system is in the lower branch of the characteristic dependence — the zone of impaired energy exchange between interacting flows, then it is necessary to completely close the adjustable gate valve 9 and then, gradually opening it, bring the system into operation in the upper branch of the characteristic dependence, without crossing the critical point (Q _GLM ^sel) _max.

For maximum system performance define optimal flowrate withdrawn liquid mixture (Q _GLM ^sel) _opt corresponding to maximum system capacity (Q _{c) max} (see. Fig. 2), and the flow withdrawn liquid mixture is maintained with a controlled valve 9 in the range 0 , 52-1.5 (Q _ghs ^otb ) _opt . The boundaries of the range are established according to experimental data, based on the condition that the decrease in system performance should not exceed 10% of (Q _s ) _max . So, for a maximum productivity of 4.62 l / s obtained in the experiments, the productivity, taking into account an acceptable 10% decrease, is 4.17 l / s. From the characteristic dependence (see Fig. 2) it follows that the boundaries of the interval in which Q _c > 4.17 l / s are the values of Qgfs srt equal to 0.4 l / s and 1.16 l / s. With respect to (Q _GLM ^sel) _opt = 0.776 l / s, these values are 0.52 and 1.5. Thus, the proposed method allows to operate the pump-ejector system in the field of the most advantageous energy exchange between the interacting flows and significantly increase the performance of the system, which makes it possible to significantly expand the scope of the pump-ejector systems in the national economy.

Claims (3)

 1. METHOD OF OPERATION OF A PUMP-EJECTOR SYSTEM, including supplying a gas-liquid mixture to the inlet of the system, separating the mixture, injecting the separated liquid and ejecting the separated gas therewith, characterized in that a part of the gas-liquid mixture supplied to the system inlet is selected and sent together with the separated gas stream for ejection with an injected separated liquid. 2. The method according to claim 1, characterized in that previously, for various costs of the selected gas-liquid mixture, a characteristic dependence is built
Q _c = f (Q _ghf ),
where Q _with - the performance of the system for gas-liquid mixture, l / s;
Q _ghs - the flow rate of the selected gas-liquid mixture, l / s;
by which the operating mode of the system is set in the range of the upper branch of the characteristic dependence, limited by the maximum flow rate of the selected gas-liquid mixture. 3. The method according to claims 1 and 2, characterized in that they determine the value of the optimal flow rate of the selected gas-liquid mixture Q _gfs.opt , corresponding to the maximum system performance, and support the flow rate of the selected gas-liquid mixture in the range (0.52 - 1.5) Q _{gfc .opt} .

Images