Experimental device and implementation method for in-situ thermal regeneration of asphalt pavement

Abstract

The present invention discloses an experimental device for the heating process of in-situ hot regeneration of asphalt pavement, comprising a heater, a pavement temperature sensor, a bottom temperature sensor and a heating resistor wire buried in the heater for heating; the heater is provided with a plurality of longitudinally penetrating sensor mounting holes, which can accommodate at least one pavement temperature sensor and one bottom temperature sensor; the pavement temperature sensor can pass through the sensor mounting hole to contact the asphalt pavement surface at the lower surface of the heater to measure the temperature of the asphalt pavement surface; the bottom temperature sensor can pass through the sensor mounting hole and be inserted into a preset hole on the asphalt pavement to measure the temperature value at a set depth of the asphalt pavement. This experimental device provides a basis for the control of heating temperature parameters during the construction of the in-situ hot regeneration unit, and solves the problems of low working efficiency and high energy consumption in the in-situ hot regeneration technology.

Description

Technical Field

[0001] The invention relates to a method and a device for conducting an experiment, and in particular to an experimental device for an in-situ hot regeneration heating process of an in-situ asphalt pavement. Background Art

[0002] In order to solve the problem of insufficient oil resources, the in-situ hot regeneration technology of asphalt pavement directly recycles waste asphalt mixture. It is heated by a heater, milled to a certain depth by a hot milling machine, and the corresponding asphalt regeneration agent and a small amount of new asphalt mixture are added. A new road surface is formed through mixing, paving and compacting. Since this method reduces the transportation of old materials and greatly shortens the road closure time, it has good economic and social benefits and has begun to be gradually applied around the world.

[0003] One of the key technologies of in-situ hot regeneration technology lies in the heating technology of asphalt pavement. However, temperature control of the asphalt pavement heating process is also the main technical difficulty of asphalt pavement heating technology in in-situ hot regeneration, especially the problem of high energy consumption, which seriously affects the promotion and application of in-situ hot regeneration technology. In-situ hot regeneration units have many equipments and complex parameter debugging. Predetermining the heating parameters of the in-situ hot regeneration units through certain experimental methods is of great significance for improving work efficiency and reducing energy consumption. Summary of the invention

[0004] In order to determine the heating parameters of the on-site hot regeneration unit and improve and solve the problems of low working efficiency and high energy consumption in the on-site hot regeneration technology, the purpose of the present invention is to provide an experimental device for simulating the on-site hot regeneration heating process of asphalt pavement at an actual working site.

[0005] In order to achieve the above object, the present invention adopts the following technical solution:

[0006] An in-situ asphalt pavement in-situ thermal regeneration heating process experimental device, comprising a heater, a pavement temperature sensor, a bottom layer temperature sensor and a heating resistance wire buried in the heater for heating;

[0007] The heater is provided with a plurality of longitudinally penetrating sensor mounting holes, which can accommodate at least one road surface temperature sensor and one bottom layer temperature sensor;

[0008] The road surface temperature sensor can pass through the sensor installation hole to contact the asphalt road surface at the lower surface of the heater to measure the temperature of the asphalt road surface;

[0009] The bottom temperature sensor can be inserted into a preset hole on the asphalt pavement through the sensor installation hole to measure the temperature value at a set depth of the asphalt pavement.

[0010] Furthermore, it also includes a spring mechanism, and the road surface temperature sensor is placed in the sensor installation hole and pressed against the asphalt road surface at the lower surface of the heater through the spring mechanism.

[0011] Furthermore, the surfaces of the heater except the lower surface are covered with a heat insulating device.

[0012] Furthermore, the heating resistance wires are evenly bent and distributed and buried inside the heater.

[0013] Furthermore, a plurality of sensor mounting holes for accommodating road surface temperature sensors are evenly distributed in a peripheral area on the heater.

[0014] Further, the sensor mounting holes for accommodating the bottom temperature sensor are distributed in the central area of ​​the heater.

[0015] Further, two bottom layer temperature sensors are provided, which are symmetrically distributed in the central area of ​​the heater.

[0016] Furthermore, a thermally conductive silicone grease layer is applied between the surface heating area where the lower surface of the heater contacts the asphalt pavement.

[0017] Furthermore, the heating resistor wire is powered by a vehicle-mounted power supply, and the output power of the heating resistor wire is adjusted by adjusting the output voltage of the vehicle-mounted power supply.

[0018] An implementation method of an in-situ asphalt pavement hot regeneration heating process experimental device comprises the following steps:

[0019] S1. Select the asphalt pavement on site for drilling;

[0020] S2. Apply a layer of thermally conductive silicone grease between the area where the lower surface of the heater contacts the surface of the asphalt pavement;

[0021] S3, aligning the sensor installation hole in the central area of ​​the heater with the pre-drilled hole on the asphalt pavement to form a through hole, and the bottom temperature sensor extends through the through hole into a position at a predetermined depth of the asphalt pavement;

[0022] The road surface temperature sensor is placed in the sensor mounting hole in the surrounding area of ​​the heater and pressed against the upper surface of the asphalt road surface by a spring mechanism;

[0023] S4, adjusting the output voltage of the programmable power supply to heat the heating resistor wire inside the heater, keeping the upper surface temperature of the asphalt pavement measured by the pavement temperature sensor stable at the set value, and the test value of the bottom temperature sensor reaching the preset value, and recording all the data;

[0024] S5. Record the time required to complete the heating, and determine the construction speed based on the time and the length of the heater;

[0025] S6. According to the integral of the heating power within the time required to complete the heating, the power required for the asphalt pavement is obtained, the efficiency of heat transfer between the heater and the asphalt pavement is determined, and the energy consumption for pavement heating is estimated.

[0026] The beneficial effects achieved by the present invention are:

[0027] This experimental device uses a vehicle-mounted power supply as the power source and a cast resistance heating device. By adjusting the working voltage of the heating resistance wire and changing the heating power, the surface temperature of the asphalt pavement is maintained at the set value required by the process during the heating process until the temperature at the regeneration depth reaches the required value. The heating power curve during the heating process and the temperature curve at different depths of the asphalt pavement are recorded to provide a basis for the heating parameter control of the in-situ hot regeneration unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 A schematic diagram of an experimental device for in-situ hot regeneration of an asphalt pavement during heating;

[0029] Figure 2 This is an experimental diagram of an experimental device for in-situ hot regeneration of asphalt pavement during heating process;

[0030] Figure 3 A flow chart of a heating process for in-situ hot regeneration of an in-situ asphalt pavement;

[0031] In the figure, 1. heater, 2. road surface temperature sensor, 3. bottom layer temperature sensor, 4. spring mechanism, 5. road surface, 6. heating resistor wire, 71. 72. sensor mounting hole, 8. hole. DETAILED DESCRIPTION

[0032] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings, which constitute a part of this application.

[0033] like Figure 1 and Figure 2 As shown, the in-situ asphalt pavement in-situ thermal regeneration heating process experimental device of the present invention includes a heater 1, a pavement temperature sensor 2, a bottom layer temperature sensor 3, a spring mechanism 4 and a heating resistor 6.

[0034] A uniformly curved heating resistor wire 6 is buried inside the heater 1 to keep the heating temperature of the lower surface of the heater 1 uniform. Except for the lower surface, other surfaces of the heater 1 are covered with a heat insulation device to ensure that all the heating energy of the heater 1 is output from the lower surface.

[0035] The heater 1 is provided with a plurality of sensor mounting holes 71 and 72, wherein the plurality of sensor mounting holes 71 distributed around the heater 1 are used to accommodate the road surface temperature sensor 2, and the two sensor mounting holes 72 arranged near the center point or only one sensor mounting hole 72 arranged at the center point are used to accommodate the bottom temperature sensor 3. The road surface temperature sensor 2 passes through the sensor mounting hole 71 and is pressed against the surface of the asphalt road surface 5 at the lower surface of the heater 1 by the spring mechanism 4 toward the asphalt road surface 5, and is used to measure the temperature of the asphalt road surface. The bottom temperature sensor 3 can be inserted into the hole 8 of the set depth pre-drilled in the asphalt road surface 5 through the sensor mounting hole 72 to measure the temperature value at the set depth of the asphalt road surface. In this embodiment, the set depth of the hole 8 is 40 mm.

[0036] The controller includes two parts: temperature acquisition and heating power control. The temperature acquisition part uses a road surface temperature sensor 2 and a bottom layer temperature sensor 3 to detect the temperature of the asphalt pavement surface and different depths inside respectively; the heating power control part automatically adjusts the voltage across the heater resistance wire 6 according to the collected asphalt pavement surface temperature, changes the heating output power, and maintains the asphalt pavement surface temperature at the set value.

[0037] This experimental device uses a vehicle-mounted power supply as the power source and a cast resistance heating device. By adjusting the working voltage of the heating resistor wire 6, the heating power is changed to maintain the surface temperature of the asphalt pavement at the set value required by the process during the heating process until the temperature at the regeneration depth reaches the required value. The heating power curve during the heating process and the temperature curve at different depths of the asphalt pavement are recorded to provide a basis for the heating parameter control of the in-situ hot regeneration unit.

[0038] The heater 1 is a rectangular parallelepiped structure with a size of 300x300x30mm and is generally made of cast copper.

[0039] On-board generator: provides system power, output power ≥5KW.

[0040] Programmable power supply: output power ≥ 5KW. Under the control of the controller, the power output of heater 1 is adjusted by changing the output voltage, thereby ensuring that the surface temperature of the asphalt pavement is the set value.

[0041] Combination Figure 3 As shown in FIG. 1 , an experimental method for the in-situ thermal regeneration heating process of an in-situ asphalt pavement is shown in FIG. 1 . The steps of the experimental method are as follows:

[0042] S1, select a site for drilling 8 on the heated pavement;

[0043] S2, apply thermal grease;

[0044] S3, installing heater 1;

[0045] S4, heating process control;

[0046] S5. Record data;

[0047] S6. Estimate heating energy consumption.

[0048] In step S1, a site is selected on site, and a hole 8 is drilled (with a depth of 40 mm and a hole diameter of 2 mm. In order to reduce the impact on the overall heat transfer, the drilling depth on site can be adjusted according to the construction requirements);

[0049] In step S2, according to the location of the heating site and the shape of the heating surface of the heater 1, the surface heating area of ​​the asphalt pavement is delineated, and a thin layer of thermal conductive silicone grease is applied between the surface heating area of ​​the asphalt pavement and the lower surface of the heater 1 to reduce the thermal resistance of heat transfer between the heater 1 and the asphalt pavement;

[0050] In step S3, the heater 1 is installed: the sensor installation hole 72 on the heater 1 is overlapped and connected with the pre-drilled hole 8 on the asphalt pavement 5, the bottom temperature sensor 3 passes through the sensor installation hole 72 and extends into the hole through the drilled hole 8 to measure the depth position (the depth position of 40 mm in this embodiment), the pavement temperature sensor 2 is placed in the sensor installation hole 71, and is pressed against the asphalt pavement surface by the spring mechanism 4 toward the asphalt pavement, and the heater 1 is covered at the position where the thermal conductive silicone grease is applied;

[0051] In step S4, the heating process is controlled by setting the road surface heating temperature through the controller, adjusting the output voltage of the programmable power supply, heating the heating resistor 6, keeping the road surface temperature measured by the road surface temperature sensor 2 stable at the set value, heating until the test value of the bottom layer temperature sensor 3 at a depth of 40 mm reaches a predetermined value, and recording all data;

[0052] In step S5, the time required to complete the heating is recorded: based on this time, combined with the length of the heater, the construction speed can be determined;

[0053] Construction speed = heater length / time;

[0054] The faster the construction speed, the greater the heating power, and vice versa. It can be used to guide the construction speed.

[0055] In step S6, heating energy: the power required by the road surface can be obtained based on the integral of the heating power within the time required to complete the heating. Combined with several construction tests, the efficiency of heat transfer between the heater 1 and the road surface is determined, and the road surface heating energy consumption is estimated.

[0056] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. An experimental device for in-situ hot regeneration of asphalt pavement, characterized in that: It includes a heater, a road surface temperature sensor, a bottom layer temperature sensor and a heating resistance wire buried inside the heater for heating; The heater is provided with a plurality of longitudinally penetrating sensor mounting holes, which can accommodate at least one road surface temperature sensor and one bottom layer temperature sensor; The surfaces of the heater other than the lower surface are covered with thermal insulation; The road surface temperature sensor can pass through the sensor installation hole to contact the asphalt road surface at the lower surface of the heater to measure the temperature of the asphalt road surface; The bottom temperature sensor can be inserted into a preset hole on the asphalt pavement through the sensor installation hole to measure the temperature value at a set depth of the asphalt pavement; A plurality of sensor mounting holes for accommodating road surface temperature sensors are evenly distributed around the heater; Sensor mounting holes for accommodating bottom temperature sensors are distributed in a central area on the heater; The sensor installation hole in the central area of ​​the heater is overlapped with the pre-drilled hole on the asphalt pavement to form a through hole, and the bottom temperature sensor is extended into the asphalt pavement through the through hole to a predetermined depth; The road surface temperature sensor is placed in the sensor mounting hole in the surrounding area of ​​the heater and pressed against the upper surface of the asphalt road surface by a spring mechanism; Adjust the output voltage of the programmable power supply to heat the heating resistor wire inside the heater, keep the upper surface temperature of the asphalt pavement measured by the pavement temperature sensor stable at the set value, and the test value of the bottom temperature sensor reaches the preset value, and record all the data; Record the time required to complete heating, and determine the construction speed based on this time and the length of the heater; construction speed = heater length / time; According to the integral of the heating power in the time required to complete the heating, the power required for the asphalt pavement is obtained, the efficiency of heat transfer between the heater and the asphalt pavement is determined, and the energy consumption of pavement heating is estimated; The heating resistance wires are evenly bent and distributed and buried inside the heater; Two bottom temperature sensors are arranged, symmetrically distributed in the central area of ​​the heater.

2. The in-situ hot regeneration heating process experimental device for in-situ asphalt pavement according to claim 1 is characterized in that: It also includes a spring mechanism. The road surface temperature sensor is placed in the sensor installation hole and is pressed against the asphalt road surface at the lower surface of the heater through the spring mechanism.

3. The in-situ hot regeneration heating process experimental device for in-situ asphalt pavement according to claim 1 is characterized in that: A layer of thermal conductive silicone grease is applied between the surface heating area where the lower surface of the heater contacts the asphalt pavement.

4. The in-situ hot regeneration heating process experimental device for in-situ asphalt pavement according to claim 1 is characterized in that: The heating resistor wire is powered by a vehicle-mounted power supply, and the output power of the heating resistor wire is adjusted by adjusting the output voltage of the vehicle-mounted power supply.

5. The implementation method of the in-situ asphalt pavement in-situ thermal regeneration heating process experimental device according to claim 1 is characterized in that: The following steps are involved: S1. Select the asphalt pavement on site for drilling; S2. Apply a layer of thermally conductive silicone grease between the area where the lower surface of the heater contacts the surface of the asphalt pavement; S3, aligning the sensor installation hole in the central area of ​​the heater with the pre-drilled hole on the asphalt pavement to form a through hole, and the bottom temperature sensor extends through the through hole into a position at a predetermined depth of the asphalt pavement; The road surface temperature sensor is placed in the sensor mounting hole in the surrounding area of ​​the heater and pressed against the upper surface of the asphalt road surface by a spring mechanism; S4, adjusting the output voltage of the programmable power supply to heat the heating resistor wire inside the heater, keeping the upper surface temperature of the asphalt pavement measured by the pavement temperature sensor stable at the set value, and the test value of the bottom temperature sensor reaching the preset value, and recording all the data; S5. Record the time required to complete the heating, and determine the construction speed based on the time and the length of the heater; S6. Obtain the power required for the asphalt pavement based on the integral of the heating power during the time required to complete the heating, determine the efficiency of heat transfer between the heater and the asphalt pavement, and estimate the pavement heating energy consumption; The heating resistance wires are evenly bent and distributed and buried inside the heater; Two bottom temperature sensors are arranged, symmetrically distributed in the central area of ​​the heater.

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