RU2450253C1 - Method of diagnosing pump operating performances - Google Patents

Abstract

FIELD: engines and pumps.

SUBSTANCE: proposed method comprises testing, measuring pressure difference P at inlet and outlet of pump 1, fluid temperature T at pump inlet and outlet, forcing preset amount of working fluid via bypass line 4 provided with controller restrictor 5 and communicating pump inlet and outlet. In all tests one pressure difference created by pump 1 and one number of pumping cycles are used. Time of pumping preset number of cycles is used as diagnostics parameters.

EFFECT: comprehensive results of diagnostics.

1 dwg

Description

The invention relates to hydraulic engineering and can be used to assess the technical condition of pumps in operating conditions.

A known method for determining the technical condition of the pump, including conducting sequential tests, measuring in each test the differential pressure at the inlet and outlet of the pump, the temperature of the liquid at the inlet to the pump, pumping during each test a fixed volume of working fluid through a bypass line with an adjustable throttle, communicating the input and the pump output, and during all tests, set the pressure drop created by the pump and the number of pumping cycles to be the same, while as a diagnostic The parameter of the parameter is the temperature increase in the pump after a given number of pumping cycles (SU 1513196 A1, 10/07/1989).

The disadvantage of this method is the lack of information, as it does not allow us to distinguish the share of volumetric energy losses from the total sum of hydraulic and volumetric losses. The measured diagnostic parameter according to the known method is proportional to the total efficiency of the pump, and such an informative parameter as volumetric efficiency is not determined.

The objective of the invention is to increase the information content of the test results of the pump during diagnosis by determining both total and volumetric losses.

The technical result is achieved by the fact that in the method for diagnosing the technical condition of the pump, which includes measuring in each test the pressure drop at the inlet and outlet of the pump, the temperature of the liquid at the inlet to the pump, pumping at each test a fixed volume of the working fluid through a bypass line with an adjustable throttle, reporting pump inlet and outlet, and during all tests, the pressure drop created by the pump and the number of pumping cycles are the same, the diagnosis is determined a parameter and an estimate of the parameter obtained during various tests of the technical condition of the pump, while the temperature increase in the pump after a given number of pumping cycles is taken as a diagnostic parameter, according to the invention, the time taken to pump a given number of cycles is also measured.

The total losses (total efficiency of the pump) are estimated by changing the temperature of the pumped liquid over a certain number of cycles of pumping it in a closed circuit, and the volume losses (volumetric efficiency of the pump) are estimated by the time during which the liquid passes a given number of cycles.

The drawing shows a hydraulic circuit of a device for implementing this method.

A device for diagnosing the technical condition of the pump 1 has an inlet and an outlet pipe 2, 3, which are interconnected by a bypass line 4 with an adjustable throttle 5. On the inlet pipe 2 there is a temperature sensor 6 T and a liquid pressure sensor 7 P ₁ at the inlet to the pump 1, and at the outlet pipe 3, a pressure sensor 8 P ₂ at the outlet of the pump 1 and a flow sensor 9. On the main line 10, valves 11 and 12 are installed, with which a fixed volume of liquid is cut off.

The diagnostic method is as follows.

At the scheduled time points, the tests of the pump 1 are carried out sequentially. First, during each test, a fixed volume of liquid in the system is cut off by shutting off the valves 11 and 12 of the main line 10, then pump 1 of the fixed volume of liquid is pumped through the bypass line 4 with an adjustable choke 5, which informs the input and the output of pump 1, and in all tests the pressure difference ΔP = P ₂ -P ₁ and the number of pumping cycles N. The number of pumping cycles N determined by the measured values of a fixed volume and total fluid flow. Using the temperature sensor 6, a temperature increase is determined after a predetermined number of pumping cycles. At the same time, the time taken for the fluid to pass a given number of cycles is measured. The current fluid flow rate is determined by the formula:

,

,

where N is the number of cycles;

v is a fixed volume of liquid;

Δt is time.

The difference between the flow rate or the pumping time of a given number of cycles determined during the first diagnosis (for a new pump) and subsequent diagnoses will characterize the change in the volumetric losses of the pump during operation.

The use of the invention will reduce current costs for maintenance and repair of the pump by increasing the information content of the diagnosis.

Claims (1)

A method for diagnosing the technical condition of the pump, including consecutive tests, measuring the pressure drop at the pump inlet and outlet in each test, the temperature of the liquid at the pump inlet, pumping at each test a fixed volume of the working fluid through a bypass line with an adjustable throttle communicating the input and output pump, and during all tests set the pressure drop created by the pump and the number of pumping cycles to be the same, determining the value of the diagnostic st parameter and the estimate of the parameter obtained at different pump conditions technical tests, at the same time as the diagnostic parameter taking the temperature rise in the pump after a predetermined number of pumping cycles, characterized in that the further measured time during which the pumping is carried out a predetermined number of cycles.