CN108169071A - Oil viscosity detection device under a kind of ultra-high voltage environment - Google Patents

Abstract

The invention belongs to the field of oil viscosity detection, in particular to a viscosity detection device under ultra-high pressure working conditions. The detection device includes end cover, O-ring 1, capillary plug, O-ring 2, O-ring 3, differential pressure sensor, connecting oil passage, capillary, pressure-resistant shell, oil pipe, temperature sensor, flow sensor , Pressure sensor, relief valve, ultra-high pressure oil pump, motor, high pressure oil tank, relief valve, oil pump, filter valve, oil-immersed motor, thermostat. The present invention uses a differential pressure sensor to obtain measurement data in a convenient manner, and an oil-immersed motor and an oil pump are installed inside the high-pressure oil tank, which eliminates the problem of high-pressure resistant rotary sealing. A low-flow ultra-high pressure pump is used to maintain the high-pressure environment of the closed measurement system, and an oil-immersed motor is used to drive the oil pump to provide a large flow of oil required for measuring the viscosity of the oil.

Description

A device for detecting oil viscosity in ultra-high pressure environment

technical field

The invention relates to the field of oil viscosity detection, in particular to a viscosity detection device under ultra-high pressure working conditions.

Background technique

The viscosity characteristics of hydraulic oil have a very important impact on the dynamic performance of the hydraulic system. For deep-sea hydraulic equipment, due to the ultra-high pressure working environment, the oil viscosity changes greatly. It is of great practical value to design a device that can be used to detect the viscosity of oil in an ultra-high pressure environment.

Viscosity, also called viscosity coefficient, is the internal friction between two layers of liquid at a certain area and a certain velocity gradient. For liquids, this is a very important physical quantity. The existing viscosity detection methods mainly include:

1. Capillary method

A capillary viscometer is an instrument designed to measure viscosity based on Hagen-Poiseuille's law. Its working principle is that when the measured liquid flows through a capillary with a radius of r and a length of 1, the flow rate q is constant, and the viscosity value can be calculated according to Hagen's law.

2. Drop ball method

Let the object fall in the fluid. The higher the viscosity of the fluid, the slower the object will fall in it. Therefore, the viscosity of the fluid can be compared by the falling speed.

3. Rotation method

The principle of the rotational viscometer is based on the rotation of objects immersed in the fluid (such as cylinders, cones, discs, balls and other rigid bodies), or when these objects are stationary and the surrounding fluid is rotated, these objects will be affected by the fluid. The effect of viscous moment, the size of the viscous moment is proportional to the viscosity of the fluid, and the viscosity of the liquid is measured by measuring the viscous moment and the speed profile of the rotating body.

Currently disclosed viscosity detection device patents are mostly used in normal pressure environments or medium and low pressure working conditions, such as the cylinder rotary viscometer disclosed in CN104122172A, the rotary online viscometer disclosed in CN202974800U, and the rotary viscometer disclosed in CU203595648U. It can only measure the viscosity of oil under normal pressure. For the high temperature and high pressure rotary viscometer disclosed in CN2852109Y and the high temperature and high pressure falling column viscometer disclosed in CN2205004, the working pressure for measuring oil viscosity is medium and low pressure. The high-temperature and high-pressure viscometer disclosed in CN101685058A cannot accurately control the pressure in the sealed cavity, and the high-pressure rotary viscometer disclosed in CN106596343A uses a magnetic force transmission device with limited driving force, which is difficult to implement and has large measurement errors.

Contents of the invention

The main problem to be solved by the present invention is to provide a method for detecting oil viscosity under ultra-high pressure conditions; to design a high-pressure closed oil tank to provide large flow and high-pressure oil for viscosity measurement; to design a A lower device that uses a capillary to detect the viscosity of high-pressure oil.

The focus of this invention is to maintain the high-pressure environment of the closed measurement system through a small-flow ultra-high-pressure pump, and use the oil-immersed motor to drive the oil pump to provide a large flow of high-pressure oil to measure its viscosity.

In order to realize above-mentioned technical purpose, the present invention will take following technical scheme:

A hydraulic oil viscosity detection device, including an end cover, an O-ring I, a capillary plug, an O-ring II, an O-ring III, a differential pressure sensor, a connecting oil passage, a capillary, a pressure-resistant housing, and an oil pipe , temperature sensor, flow sensor, pressure sensor, relief valve, ultra-high pressure oil pump, motor, high pressure oil tank, relief valve, oil pump, filter valve, oil-immersed motor, thermostat.

The motor drives the ultra-high pressure oil pump to input hydraulic oil into the closed oil tank to increase the internal pressure. The oil-immersed motor in the oil tank drives the oil pump to output a certain flow of hydraulic oil, which is adjusted to the temperature required by the measurement through the thermostat.

The hydraulic oil with a certain pressure and temperature output from the high-pressure oil tank and the thermostat enters the capillary viscosity measuring device through the oil pipe.

In order to ensure the sealing condition, there is a layer of O-ring seal 1 and the matching gasket between the end covers on both sides and the pressure-resistant shell. There are two O-ring seals 2 between the pressure-resistant shell and the capillary plug. There are two O-rings three between the plug and the capillary.

After the hydraulic oil flows through the capillary, it returns to the inside of the closed oil tank through the right end cap, through the oil pipe and the flow sensor, and enters the circulation again.

Further, the oil-immersed motor in the oil tank drives the hydraulic oil pump to output a certain flow of oil, which is supplied to the viscosity detection device after passing through the thermostat. When the output pressure is too high, the overflow valve works to ensure the safety of the system.

Furthermore, the high-pressure oil flows through the capillary inside the viscosity detection device. Due to the viscosity of the oil, the pressure of the oil will drop when passing through the capillary. The pressure between the two pressure measuring points can be measured by a high-precision differential pressure sensor. Difference.

Further, the high-precision differential pressure sensor is used to measure the pressure difference in the stable flow field between the two measuring points inside the capillary, and the flow sensor is used to measure the oil flow through the capillary, and the theoretical formula is used to calculate the oil under high-pressure working conditions. under the viscosity value.

Compared with the traditional viscosity detection device, the present invention has the main advantages of:

1. The motor and oil pump are immersed in high-pressure oil environment, which can provide high-pressure and large-flow oil for viscosity measurement, which solves the problem of high-pressure rotary sealing.

2. The immersion capillary viscosity detection in high-pressure environment reduces the manufacturing difficulty and sealing requirements of the high-pressure viscosity detection device.

3. Using theoretical formulas, the relationship between the pressure change and its viscosity in the process of oil flow is converted into an easy-to-implement device for fluid viscosity testing.

Viscosity calculation formula:

In the formula, η is the kinematic viscosity of the measured liquid; ΔP is the pressure difference between the two pressure measuring points obtained by the differential pressure sensor; R is the radius of the outer wall pipe of the flow field; q _v is the oil flow rate flowing through the capillary; L is the capillary The distance between two pressure measuring points.

Description of drawings

Fig. 1 is a device structural diagram of the present invention, among the figure

1-End cover; 2-O-type sealing ring 1; 3-capillary plug; 4-O-type sealing ring 2; 5-O-type sealing ring 3; 6-differential pressure sensor; ;9-pressure-resistant shell; 10-oil pipe; 11-temperature sensor; 12-flow sensor; 13-pressure sensor; 14-overflow valve; 15-ultra-high pressure pump; 16-motor; Relief valve; 19-oil pump; 20-filter valve; 21-oil-immersed motor; 22-thermostat.

Detailed ways

The present invention will be further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

The motor 16 drives the ultra-high pressure oil pump 15 to input hydraulic oil to the closed oil tank 17 to increase its internal pressure. The oil-immersed motor 21 in the oil tank drives the oil pump 19 to output a certain flow of hydraulic oil, which is adjusted to the temperature required by the measurement through the thermostat.

The hydraulic oil with a certain pressure and temperature output from the oil tank 17 and the thermostat 22 passes through the oil pipe 10 and enters the capillary viscosity measuring device. Furthermore, due to the viscosity of the hydraulic oil, the pressure drops when the hydraulic oil flows through the capillary 8, and the high-precision differential pressure sensor 6 can measure the pressure difference between the two pressure measuring points.

In order to ensure the sealing condition, there is a layer of O-shaped sealing ring 1 and the matching gasket between the end covers 1 on both sides and the pressure-resistant shell 9, and there are two O-shaped seals between the pressure-resistant shell 9 and the capillary plug 3. Sealing ring two 4, there are two O-shaped sealing rings three 5 between the capillary plug 3 and the capillary 8.

After the hydraulic oil flows through the capillary, the right end cap passes through the oil pipe 10 and the flow sensor 12, returns to the inside of the closed oil tank, and enters the circulation again.

Since the motor and oil pump are all immersed inside the oil tank, there is no need for a high-pressure rotary seal.

The oil passage 7 connects the closed space between the two pressure measuring points and the outside of the capillary with the high-pressure oil inside the pressure-resistant housing 9, which reduces the pressure difference between the two ends of the sealing rings 4 and 5 and reduces the difficulty of sealing.

Claims (4)

1. a kind of hydraulic oil viscosity detection device, it is characterised in that detection device includes end cap, O-ring seal one, capillary pipe plug Head, O-ring seal two, O-ring seal three, differential pressure pickup, connection oil duct, capillary, pressure hull, oil pipe, temperature sensing Device, flow sensor, pressure sensor, overflow valve, superpressure oil pump, motor, pressure-oil tank, overflow valve, oil pump, strainer valve, Immersion oil motor, thermosistor；

Motor drives superpressure oil pump to improve its internal pressure, the immersion oil motor in fuel tank to closed fuel tank input hydraulic pressure oil Oil pump is driven, exports the hydraulic oil of certain flow, the temperature to measurement request is adjusted by thermosistor；

There is certain pressure and the hydraulic oil of temperature by what pressure-oil tank and thermosistor exported, enter capillary type by oil pipe and glue It spends inside measuring device；

There are one layer of O-ring seals one and matched washer, pressure hull and capillary between both sides end cap and pressure hull There are O-ring seals two at two between pipe plug, there are O-ring seals three at two between capillary pipe plug and capillary；

Hydraulic oil is flowed through after capillary by right side end cap, by oil pipe, flow sensor, is returned to inside closed fuel tank, again into Enter cycle.

A kind of 2. hydraulic oil viscosity detection device as described in claim 1, it is characterised in that the immersion oil motor driven liquid in fuel tank Pressure oil pump exports the fluid of certain flow, by supplying viscosity detecting device after thermosistor, when output pressure is excessively high, and overflow valve Work, to ensure system safety.

3. a kind of hydraulic oil viscosity detection device as described in claim 1, it is characterised in that high-voltage oil liquid flows through viscosity measurements dress Internal capillary is put, due to the viscous effect of fluid, fluid can generate pressure decline when passing through capillary, be pressed by high-precision Gap sensor can measure the pressure differential between two pressure-measuring-points.

4. a kind of hydraulic oil viscosity detection device as described in claim 1, it is characterised in that surveyed using high-precision differential pressure pickup The pressure differential of steady flow condition between two measuring points inside capillary is measured, the fluid stream by capillary is measured using flow sensor Amount, is calculated by theoretical formula, can obtain viscosity number of the fluid under high pressure operations.