RU2343319C2 - Method of pump station startup to run mode - Google Patents

Abstract

FIELD: motors and pumps.

SUBSTANCE: invention relates to hydraulic machinery construction and may be used for startup pumping unit arranged in parallel and with drooping head-flow characteristics. Startup method provides for initial startup and bringing to running mode one pumping unit. Then the second pumping unit is started up and liquid carryover is performed through by-pass from the second pumping unit outlet to inlet in the amounts sufficient for outlet pressure being equal to the pressure behind the initially started unit. After that, the transverse chokes are opened ensuring liquid supply from the second unit into the main line, while liquid carryover is terminated through the bypass by means of the mounted gate valve.

EFFECT: ensures bringing to the running mode of pumping station with drooping head-flow characteristics.

1 dwg

Description

The invention relates to hydraulic engineering and can be used in the operation of pumps, in particular pump units installed in parallel, having a flowing pressure characteristic at low flows (0≤Q≤Qopt).

A known method of joint parallel operation of centrifugal pumps (see E.Z. Rabinovich, A.E. Rotte. Pumping installations in the oil, petrochemical and gas industries. Moscow, Nedra, 1965, p.145).

The disadvantage of this method is that it regulates only the procedure for constructing and determining the flow and pressure of pumps running in parallel to a given network, including the supply and pressure of each (first and second) pump. It is indicated that “in parallel operation, the pumps are connected to the pipeline independently of each other and each of them has its own receiving and pressure lines; the latter are connected to a common trunk pipeline. ” It does not indicate how it is possible to start the pumps and their operation with the total pressure characteristic determined by the described method.

Closest to the invention is a technical solution (see A.K. Mikhailov, V.V. Malyushenko. Vane pumps. Moscow, Mashinostroyenie, 1977, p. 287), according to which parallel connection of the pumps is most effective with a gentle characteristic of the system. The pumps are started up at the same speed at the same time, gradually opening the valves on both pumps.

The disadvantage is that the known technical solution does not allow a reliable start-up of parallel-connected pump units with a gentle downward pressure characteristic in its left part, since even with the simultaneous gradual opening of the valve on both pumps, one pump can be “blocked” by the other. This “locking” can be caused by a number of reasons: different resistance of flow lines (up to the point of confluence of flows), deviation of pressure characteristics of identical pumps from passport ones, due to non-compliance with design geometric dimensions within tolerances. In addition, the simultaneous start-up of pumping units can be attributed to the disadvantages, since in practice this is not always justified (for example, when it is necessary to turn on the second pump when one pump is already running).

The objective of the invention is the provision of the possibility of bringing to operation the pumping station with a flowing pressure characteristic at low feeds.

The technical result is achieved by the fact that in the method of starting up an operating mode of a pumping station, consisting of full-pressure centrifugal pumping units arranged in a parallel circuit and having a downward pressure characteristic in the left part (0≤Q≤Qopt), according to the invention, start-up and output to operating first, the mode of one pumping unit, after which the second unit is put into operation and through the bypass line they provide liquid bypass from the outlet to the inlet of the second unit in such an amount that the outlet pressure talo equal to the pressure of the pump unit included first, open secant valve providing fluid flow from the second unit in the line is stopped and both bypass liquid through the bypass line via valves located thereon.

The drawing shows a diagram for implementing the method of starting the operating mode of the pumping station.

The circuit for implementation includes pumps 1 and 2 connected in parallel, pressure gauges 3, valves 4, 5, 6 and 7 and a bypass line 8.

The method is implemented as follows.

Initially, the pump unit 1 is started up and put into operation when the valves 4 and 5 are open and the valves 6 and 7 are closed. Then the pump unit 2 is put into operation and bypass line 8 provides the liquid bypass from the output to the input of the second pump unit in such quantity so that the outlet pressure becomes equal to the pressure behind the pumping unit, which is turned on first, which is monitored using pressure gauges 3 with an open valve 7, which ensures the flow of fluid from the second pumping unit into the line, and simultaneously enno bypass fluid stop by the bypass line 8 by closing valve 7 and opening the valve 6.

The use of the invention will allow to start the pumping station for operation, containing full-pressure centrifugal pumping units connected in a parallel circuit and having a flowing pressure characteristic at low flows (0≤Q≤Qopt).

Claims (1)

The method of starting up the pumping station, which consists of full-pressure centrifugal pumping units arranged in parallel and having a flowing pressure characteristic in the left part (0≤Q≤Qopt), which consists in starting and starting up one pumping pump of the unit, after which the second unit is put into operation and through the bypass line the liquid is transferred from the outlet to the inlet of the second unit in such a quantity that the outlet pressure becomes equal to the pressure behind the pump unit , switched on by the first, open the secant gate valve, which ensures the flow of fluid from the second unit to the main line, and at the same time stop the fluid bypass through the bypass line using the gate valve located on it.