CN107449625B - Piping axial directional displacement test device considering seabed inclination angle and cooling gradient - Google Patents

Abstract

The invention discloses a kind of consideration sea bed inclination angle and the pipeline axial orientation racking test devices of falling temperature gradient, it is characterized by comprising test flume, oil transporting appliance, oil outlet pipe, oil return line, import acquisition device, outlet acquisition device, test petroleum pipeline, turning gear and hydraulic push rod devices, the device can simulate a variety of scenes for causing submarine pipeline that axial orientation displacement occurs: pipeline is during whole uniformly heating, cooling, due to the inclined effect of sea bed, so that axial orientation displacement occur；The oil product of fixed temperature is heated to during through pipeline inside, carries out energy exchange with pipeline, when along journey energy loss, pipeline generates axial orientation displacement.

Description

Piping axial directional displacement test device considering seabed inclination angle and cooling gradient

technical field

The invention belongs to the field of marine oil transportation engineering, and in particular relates to a pipeline axial orientation displacement test device considering seabed inclination angle and cooling gradient.

Background technique

Axial directional movement of pipelines is a new problem in deep sea pipeline engineering, which is often found in pipelines that cannot be completely restrained by foundation soil. Since the deep-sea pipeline is placed bare on the seabed surface and the opening and closing operations are relatively frequent, when the pipeline is affected by the inclination of the seabed surface or the loss in the temperature conduction process, it will cause the overall movement of the pipeline along the slope end or the temperature rise end. This phenomenon is called pipeline walking. The actual measurement data of the submarine pipeline reveals that the axial movement of each kilometer of submarine pipeline can reach tens of centimeters during one opening and closing process, and the axial movement of the submarine pipeline can reach several meters during the entire service period of the submarine pipeline. Therefore, the combination of temperature and pressure and the reciprocating action cause the pipeline to move axially and directionally, which must be considered in the design of deep-sea pipelines. However, due to factors such as the difficulty of tilting the conventional test tank, the difficulty of monitoring the oil delivery temperature, and the difficulty of controlling the flatness of the soil surface, at present, the global academic and industrial circles mainly use theoretical analysis and numerical simulation methods to study the law of the axial directional movement of pipelines. The field of experimental research is basically in a blank state. This situation is not conducive to the prediction of the axial movement of submarine pipelines, and there are certain hidden dangers in the safe production of submarine pipelines.

Contents of the invention

The invention overcomes the disadvantages of the prior art, and provides a pipeline axial orientation displacement test device considering the seabed inclination angle and temperature drop gradient.

In order to solve the above technical problems, the present invention is achieved through the following technical solutions:

A pipeline axial directional displacement test device considering seabed inclination and temperature drop gradient, including test tank, oil delivery equipment, oil outlet pipeline, oil return pipeline, inlet collection device, outlet collection device, test oil delivery pipe, rotating shaft device and hydraulic pusher Rod device, the test oil delivery pipe is set in the test tank, and the two ends of the test oil delivery pipe are respectively equipped with an inlet collection device and an outlet collection device. The oil delivery equipment is connected with the inlet collection device through the oil outlet pipeline, and connected with the outlet collection device through the oil return pipeline. There is a rotating shaft device and a hydraulic push rod device under the test tank;

The bottom of the tank body of the test tank is supported by upright columns, tempered glass is installed on both sides of the tank body in the axial direction, a soil layer is laid in the tank body, the oil pipeline is placed on the soil layer, and support frames are set at both ends of the tank body. An inlet collection device and an outlet collection device are respectively arranged on the support frames at both ends, and the inlet collection device and the outlet collection device have the same structure, and are composed of a slide rail, a slider, a connecting sleeve, a pressure sensor, a temperature sensor and a laser displacement sensor. The two ends of the oil pipeline are respectively connected with the connecting sleeves of the inlet collection device and the outlet collection device;

The connection relationship of the various parts of the inlet collection device is as follows: the slide rail is arranged on the support frame, a slide block is arranged on the slide rail, the upper part of the slide block is connected with the connection sleeve, the inward side of the connection sleeve is connected with the test oil delivery pipe, and the connection sleeve The outward side is sequentially connected with a pressure sensor, a temperature sensor and an oil outlet pipeline, and the outlet collecting device has the same structure as the inlet collecting device;

In addition to the temperature sensors installed at the inlet and outlet of the test oil pipeline, patch-type temperature sensors are also equidistantly arranged on the test oil pipeline to measure the temperature change of the pipeline during the passage of high-temperature oil. A laser displacement sensor is set on the rail to measure the displacement of the slider on the rail during the experiment, which is caused by the expansion of the test oil pipeline;

The oil delivery equipment includes an upper oil tank and a lower oil tank. The lower oil tank is connected to the oil outlet pipeline, and the upper oil tank is connected to the oil return pipeline. The lower oil tank is used to keep the test oil warm and enter the pipeline, and the upper oil tank is used to collect the returned oil. The upper oil tank and the lower oil tank are connected by a connecting pipeline, and a thermal insulation device is installed in the lower oil tank to maintain the temperature of the test oil, and a proportional valve is installed at the outlet of the oil outlet pipeline.

In the above technical solution, the length of the tank body is 9-9.5m, the width is 0.5-1m, and the height is 0.5-1m.

In the above technical solution, two rows of columns are arranged in parallel at the bottom of the tank body, the number is 7-8 groups, and the columns of each group are arranged at equal intervals.

In the above technical solution, the tempered glass is transparent, which is convenient for observing the thickness of the test soil layer and the disturbance of the soil caused by the movement of the pipeline.

In the above technical solution, the proportional valve is used to adjust the oil outlet speed, so that the oil outlet speed is controlled at 5mL/s to 1L/s.

In the above technical solution, the laser displacement sensor is connected to the PC terminal through a data acquisition instrument to acquire real-time monitoring data.

In the above technical solution, the patch temperature sensors are equidistantly arranged on the oil delivery pipeline with a distance of 0.8-1m.

In the above technical solution, the rotating shaft device is composed of a bottom fixed bracket and a rotating shaft located on its upper part, so that the entire test tank is turned over with the rotating shaft as a fulcrum, and the turning angle is 0-8 degrees.

In the above technical solution, the hydraulic push rod device includes a hydraulic cylinder and a sleeve.

In the above technical solution, the rotating shaft device is arranged on the side of the oil return pipeline, the hydraulic push rod device is arranged on the side of the oil outlet pipeline, and the distance from the inlet collection device is 1/4-1/3 of the length of the test tank.

The above-mentioned pipeline axial directional displacement test device considering the seabed inclination angle and cooling gradient is carried out according to the following steps when conducting the test:

Connect the oil pipe to the test pipe, open the heat preservation device, adjust the oil temperature to the temperature required for the test, and then connect the sensor, data acquisition instrument and PC end; after completing the installation work, use the hydraulic push rod device to lift one end of the test tank to the desired temperature Height, open the large valve of the proportional valve of the heating box to let the hot oil pass through the test pipeline quickly, and the oil flowing out of the pipeline returns to the upper oil tank. At room temperature, repeat the above steps several times, measure the axial displacement of the pipeline, the temperature of the pipe wall, and the strain during the whole process, and then calculate the axial directional displacement of the pipeline for each heating and cooling cycle.

When exploring the axial displacement of the pipeline due to the influence of temperature and thermal gradient, it is not necessary to raise the test tank, and when controlling the proportional valve of the heating box, the low-speed valve should be selected to ensure that the speed of the test oil passing through the pipeline is slow enough, which can Fully heat exchange with the pipeline and the surrounding environment, so that the axial orientation displacement of the pipeline is significantly affected by the temperature effect. Among other things, other operations are consistent with the process of investigating the axial displacement of the pipeline affected by the inclination of the seabed surface.

Compared with prior art, the beneficial effect of the present invention is:

The present invention aims to design a pipeline axial directional displacement test device that can consider the seabed inclination angle and cooling gradient. The device can simulate various scenarios that lead to the axial directional displacement of the submarine pipeline:

1. During the overall uniform heating and cooling process of the pipeline, due to the inclination of the seabed, axial directional displacement occurs;

2. The oil heated to a fixed temperature exchanges energy with the pipeline during the process of passing through the pipeline. When the energy is lost along the way, the pipeline will produce axial directional displacement.

For the above two scenarios, the device can change the inclination angle of the seabed and measure the cooling gradient of the pipeline, thereby obtaining the relationship between the axial directional displacement of the submarine pipeline, the inclination angle and the cooling gradient, and predicting the axial directional displacement of the pipeline. Prevent the axial displacement of the pipeline from causing overstress in the tee/cross or crossover pipeline connected to the pipeline, loss of tension in the catenary riser, excessive stress at the horizontal buckling of the pipeline, etc.

Description of drawings

Figure 1 is a schematic diagram of the overall structure of the present invention.

Fig. 2 is a structural schematic diagram of the oil delivery equipment in the present invention.

Fig. 3 is a schematic structural diagram of the inlet collection device in the present invention.

Fig. 4 is a schematic diagram of the connection structure of the test tank, the rotating shaft device and the push rod device in the present invention.

Among them, 1 is the oil delivery equipment, 1-1 is the upper oil tank, 1-2 is the lower oil tank, 1-3 is the connecting pipeline, 1-4 is the heat preservation device, 1-5 is the proportional valve, 2 is the inlet collection device, 2 -1 is the slide rail, 2-2 is the slider, 2-3 is the connecting sleeve, 2-4 is the pressure sensor, 2-5 is the temperature sensor, 2-6 is the laser displacement sensor, 3 is the test tank, 3-1 3-2 is a support frame, 3-3 is a column, 4 is an outlet collection device, 5 is an oil return pipeline, 6 is an oil outlet pipeline, 7 is a rotating shaft device, and 8 is a hydraulic push rod device.

Detailed ways

Below in conjunction with accompanying drawing and specific embodiment the present invention is described in further detail:

As shown in the accompanying drawings, a pipeline axial orientation displacement test device considering seabed inclination angle and cooling gradient includes test tank 3, oil delivery equipment 1, oil outlet pipeline 6, oil return pipeline 5, inlet collection device 2, outlet Acquisition device 4, test oil delivery pipe, rotating shaft device 7 and hydraulic push rod device 8, the test oil delivery pipe is arranged in the test tank, and the two ends of the test oil delivery pipe are respectively provided with an inlet collection device and an outlet collection device. The inlet collection device is connected to the outlet collection device through the oil return pipeline, and a rotating shaft device and a hydraulic push rod device are installed under the test tank;

The bottom of the tank body 3-1 of the test tank is supported by the column 3-3, toughened glass is installed on both sides of the tank body in the axial direction, a soil layer is laid in the tank body, and the oil pipeline is placed on the soil layer. The end is provided with a support frame 3-2, and the import collection device and the exit collection device are respectively arranged on the support frames at both ends. -2. Connecting sleeve 2-3, pressure sensor 2-4, temperature sensor 2-5 and laser displacement sensor 2-6, the two ends of the oil pipeline are respectively connected with the connecting sleeves of the inlet collection device and the outlet collection device;

The connection relationship of the various parts of the inlet collection device is as follows: the slide rail is arranged on the support frame, a slide block is arranged on the slide rail, the upper part of the slide block is connected with the connection sleeve, the inward side of the connection sleeve is connected with the test oil delivery pipe, and the connection sleeve The outward side is sequentially connected with a pressure sensor, a temperature sensor and an oil outlet pipeline, and the outlet collecting device has the same structure as the inlet collecting device;

In addition to the temperature sensors installed at the inlet and outlet of the test oil pipeline, patch-type temperature sensors are also equidistantly arranged on the test oil pipeline to measure the temperature change of the pipeline during the passage of high-temperature oil. A laser displacement sensor is set on the rail to measure the displacement of the slider on the rail during the experiment, which is caused by the expansion of the test oil pipeline;

The oil delivery equipment includes an upper oil tank 1-1 and a lower oil tank 1-2. The lower oil tank is connected to the oil outlet pipeline, and the upper oil tank is connected to the oil return pipeline. The lower oil tank is used to keep the test oil warm and enter the pipeline. For the oil after reflow, the upper oil tank and the lower oil tank are connected through the connecting pipeline, and a heat preservation device is installed in the lower oil tank to maintain the temperature of the test oil, and a proportional valve 1-5 is installed at the outlet of the oil outlet pipeline .

In the above technical solution, the length of the tank body is 9m, the width is 0.5m, and the height is 0.5m.

In the above technical solution, two rows of columns are arranged in parallel at the bottom of the tank body, the number is 7 groups, and the columns of each group are arranged at equal intervals.

In the above technical solution, the tempered glass is transparent, which is convenient for observing the thickness of the test soil layer and the disturbance of the soil caused by the movement of the pipeline.

In the above technical solution, the proportional valve is used to adjust the oil outlet speed so that the oil outlet speed is controlled at 5mL/s.

In the above technical solution, the laser displacement sensor is connected to the PC terminal through a data acquisition instrument to acquire real-time monitoring data.

In the above technical solution, the patch temperature sensors are equidistantly arranged on the oil delivery pipeline with a distance of 0.8m.

In the above technical solution, the rotating shaft device is composed of a bottom fixed bracket and a rotating shaft located on its upper part, so that the entire test tank is turned over with the rotating shaft as a fulcrum, and the turning angle is 0-8 degrees.

In the above technical solution, the hydraulic push rod device includes a hydraulic cylinder and a sleeve.

In the above technical solution, the rotating shaft device is arranged on the side of the oil return pipeline, the hydraulic push rod device is arranged on the side of the oil outlet pipeline, and the distance from the inlet collection device is 1/4 of the length of the test tank.

Example:

This test intends to study the axial directional displacement law of the pipeline when the pipeline is placed on the soil surface with an inclination angle of 3°, and 80°C heat transfer oil is continuously and rapidly injected.

Test preparation stage:

The sand used in the test:

Homogeneous Bohai sea sand was selected, and the maximum dry density of the sand was measured to be 1732kg/m ³ , and the minimum dry density was 1555kg/m ³ , and then soil samples were prepared according to Dr=0.6 (density 1657kg/m ³ ), and filled into the test by the falling rain method groove.

pipeline:

The test uses a 9-meter-long aluminum tube with an outer diameter of 36 mm, an inner diameter of 3 mm, and a thermal expansion coefficient of 2.32*10-5/°C. Including both ends, a patch temperature sensor is pasted every 1 meter on the pipeline, a total of 10 patch temperature sensors. Connect the sensor with the data collector and the PC.

Test oil:

The oil used in the test is heat conduction oil, which has the performance of resisting thermal cracking and chemical oxidation, good heat transfer efficiency, fast heat dissipation, and good thermal stability.

Trial phase:

The pipeline is placed on the sand, and both ends are connected to the platform, and the joints are sealed with waterproof tape to ensure that the oil does not spill out during the test. Turn on the heating and heat preservation device of the oil tank, and preheat the heat transfer oil to 80°C. Operate the hydraulic cylinder to rise 0.8 meters to make the test tank tilt 5°. Open the proportional valve, the oil speed is 1L/s, and the oil is quickly passed into the pipeline. The temperature difference between the oil inlet and the oil outlet measured by the ordinary temperature sensors at both ends does not exceed 1°C. It can be considered that the oil temperature does not change significantly when passing through the pipeline, that is, the pipeline heats up evenly. When the temperature of the pipeline is stable at 80°C, close the valve of the oil tank to allow the temperature of the pipeline and the remaining oil in the pipeline to dissipate heat naturally. When the temperature rises and falls, the expansion and contraction of the pipeline drive the platforms at both ends to slide, and the readings of the laser displacement sensor are collected throughout the process, which is the displacement change at both ends of the pipeline. After the temperature drops to room temperature, open the oil return valve and drain the residual heat transfer oil in the pipe. Repeat the above steps several times to obtain the cumulative displacement. Throughout the process, the disturbance range of the pipeline movement to the soil can be observed.

After the test:

Organize the instruments and process the data. It is estimated that after 15 cycles, the pipeline can produce a net displacement of 5-10cm to the tension side.

The present invention has been described in detail above, but the content described is only a preferred embodiment of the present invention, and cannot be considered as limiting the implementation scope of the present invention. All equivalent changes and improvements made according to the application scope of the present invention shall still belong to the scope covered by the patent of the present invention.

Claims (10)

1. a kind of pipeline axial orientation racking test device for considering sea bed inclination angle and falling temperature gradient, it is characterised in that: including examination Check of foundation subsoil, oil transporting appliance, oil outlet pipe, oil return line, import acquisition device, outlet acquisition device, test petroleum pipeline, turning gear And hydraulic push rod device, test petroleum pipeline are set in test flume, are respectively arranged with import acquisition at the both ends of test petroleum pipeline Device and outlet acquisition device, oil transporting appliance are connected by oil outlet pipe with import acquisition device, and oil return line and outlet are passed through Acquisition device is provided with turning gear and hydraulic push rod device below test flume；

The groove body bottom of test flume is equipped with tempered glass, soil layer is covered in groove body by upright supports, the two sides of groove body axial direction, Pipeline road is placed on soil layer, and the both ends of groove body are provided with support frame, import is respectively set on the support frame at both ends Acquisition device and outlet acquisition device, the import acquisition device and outlet acquisition device are by sliding rail, sliding block, connector sleeve, pressure Force snesor, temperature sensor and laser displacement sensor are constituted, and the both ends of pipeline road are respectively with import acquisition device and out The connector sleeve of mouth acquisition device is connected；

The connection relationship of each component of import acquisition device are as follows: sliding rail is set on support frame, is provided with sliding block on the slide rail, Sliding block top is connected with connector sleeve, and the inside side of connector sleeve is connected with test petroleum pipeline, and the outside side of connector sleeve is sequentially connected pressure Force snesor, temperature sensor and oil outlet pipe, the outlet acquisition device and import acquisition device structure having the same；

Other than being set to the temperature sensor of test petroleum pipeline inlet and outlet, the also equidistant setting on test petroleum pipeline There is patch type temperature sensor, is provided with laser displacement sensor on the slide rail；

Oil transporting appliance includes upper layer fuel tank and lower layer's fuel tank, and lower layer's fuel tank connects oil outlet pipe, and upside fuel tank connects oil return line, For lower layer's fuel tank for test oil keep the temperature to and be passed through pipeline, upper layer fuel tank is used to collect the oil product after flowing back, upper layer fuel tank with Lower layer's fuel tank is connected by connecting line, is provided with attemperator in lower layer's fuel tank, for keeping the temperature of test oil, The exit of oil outlet pipe is provided with proportioning valve.

2. a kind of pipeline axial orientation racking test dress for considering sea bed inclination angle and falling temperature gradient according to claim 1 It sets, it is characterised in that: the length of the groove body is 9-9.5m, width 0.5-1m, is highly 0.5-1m.

3. a kind of pipeline axial orientation racking test dress for considering sea bed inclination angle and falling temperature gradient according to claim 1 It sets, it is characterised in that: groove body bottom parallel is furnished with two rows of columns, and it is equidistant between each group column that quantity, which is 7-8 group, Setting.

4. a kind of pipeline axial orientation racking test dress for considering sea bed inclination angle and falling temperature gradient according to claim 1 Set, it is characterised in that: the tempered glass be it is transparent, convenient for observation test soil thickness and pipeline movement the soil body is disturbed It is dynamic.

5. a kind of pipeline axial orientation racking test dress for considering sea bed inclination angle and falling temperature gradient according to claim 1 It sets, it is characterised in that: in the proportioning valve for adjusting Extraction rate, make Extraction rate control in 5mL/s to 1L/s.

6. a kind of pipeline axial orientation racking test dress for considering sea bed inclination angle and falling temperature gradient according to claim 1 It sets, it is characterised in that: the laser displacement sensor is adopted instrument by number and connect with the end PC, and Real-time Monitoring Data is measured.

7. a kind of pipeline axial orientation racking test dress for considering sea bed inclination angle and falling temperature gradient according to claim 1 It sets, it is characterised in that: the patch type temperature sensor is equidistant to be set on pipeline road, spacing 0.8-1m.

8. a kind of pipeline axial orientation racking test dress for considering sea bed inclination angle and falling temperature gradient according to claim 1 Set, it is characterised in that: the turning gear is made of the shaft of bottom fastening bracket and portion disposed thereon, make entire test flume with Shaft is that fulcrum is overturn, and the angle of overturning is 0-8 degree.

9. a kind of pipeline axial orientation racking test dress for considering sea bed inclination angle and falling temperature gradient according to claim 1 It sets, it is characterised in that: the hydraulic push rod device includes hydraulic cylinder and sleeve.

10. a kind of pipeline axial orientation racking test dress for considering sea bed inclination angle and falling temperature gradient according to claim 1 It sets, it is characterised in that: the turning gear is set to oil return line side, and hydraulic push rod device is set to oil outlet pipe side, Distance apart from import acquisition device is to test the 1/4-1/3 of slot length.