CN115326867A - Air curtain heat preservation model test system and test method thereof - Google Patents
Air curtain heat preservation model test system and test method thereof Download PDFInfo
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- CN115326867A CN115326867A CN202210878679.9A CN202210878679A CN115326867A CN 115326867 A CN115326867 A CN 115326867A CN 202210878679 A CN202210878679 A CN 202210878679A CN 115326867 A CN115326867 A CN 115326867A
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Abstract
The invention provides an air curtain heat preservation model test system and a test method thereof, wherein the system comprises: the shed tunnel model simulates an external shed tunnel at the front end of the tunnel main body; the environment system is used for adjusting the environment temperature and the wind parameters of the shed tunnel model; the air curtain system simulates different jet flow wind speeds and jet flow angles of air in the shed tunnel model; a test system coupled to the environmental system and the air curtain system; the method comprises the following steps: setting the temperature of the refrigeration house, and closing a door of the refrigeration house; acquiring the recording data of the temperature recorder, and adjusting the angle adjuster after the recording data reach the test temperature; opening an air curtain machine, and closing a door of the refrigeration house; setting the recording interval of a temperature recorder to be 1s, closing an air curtain machine in a cold storage, and ending a test; and (6) exporting data and analyzing. The system and the test method thereof can actively isolate and simulate the external cold airflow, and can obtain good test effect.
Description
Technical Field
The invention belongs to the technical field of tunnel environment simulation, and particularly relates to an air curtain heat preservation model test system and a test method thereof.
Background
The tunnel freeze injury refers to the phenomena of ice hanging at the arch part of the tunnel, icing of side walls, lining spalling and the like caused by the accumulated water freezing of cement and surrounding rocks in the tunnel in a cold season area, and the tunnel freeze injury has serious threat to the normal use of the tunnel.
The freeze injury of the tunnel is mainly caused by 3 points:
1. natural factors, which can be divided into severe cold (the average temperature of the coldest month is less than minus 10 ℃), cold (the average temperature of the coldest month is between minus 10 ℃ and minus 3 ℃), and mild (the average temperature of the coldest month is higher than minus 3 ℃); the cold air and the tunnel surrounding rock are subjected to convective heat transfer, so that the root cause of the freeze injury is the cold air and the tunnel surrounding rock;
2. the flowing of natural wind, which is a power factor, can bring external severe cold air into the tunnel;
3. time factor-during a sufficiently long freezing time, the tunnel will freeze.
At present, the main technological means that current solution tunnel freeze injury took reaches tunnel heat preservation's purpose through reducing the coefficient of heat conductivity between tunnel structure and the chilly natural wind stream through laying the heat preservation at tunnel entrance to a cave section, and traditional heat preservation method nevertheless belongs to passive heat preservation technique, and the reply to engineering and natural environment is comparatively passive promptly, specifically can embody in following 4 points:
1. the heat preservation layer can only reduce the heat transmission and freeze thawing speed, the larger the thickness of the heat preservation layer is, the better the heat preservation effect is, but is limited by engineering, the thickness of the heat preservation layer paved on the tunnel is usually not more than 10cm, which indicates that the tunnel lining and surrounding rocks are also likely to be frozen in regions with long lasting cold climate;
2. the heat insulation layer laid by the tunnel lining belongs to bidirectional heat insulation, so that the ablation can be delayed in the spring thawing period while the freezing injury of the tunnel is delayed in winter, and the tunnel can possibly leak;
3. in the laying process, the heat insulation layer is damaged, the heat insulation effect is influenced, meanwhile, the heat insulation layer is possibly influenced by factors such as water seepage of surrounding rocks in service time, and the heat insulation effect is gradually reduced along with the increase of time;
4. the laying method of the heat preservation layer in the engineering is generally divided into a surface spraying method (tunnel lining is directly sprayed with a rapid hardening heat preservation material and is firstly applied to a black dragon river rime ridge tunnel), a wall pasting method (is directly laid on the inner wall of a secondary lining) and a sandwich type method (is laid between a primary support and the secondary lining and is firstly applied to a tunnel in the province of ladders in the north of river), and when the heat preservation effect is reduced, the replacement of the heat preservation layer wastes time and labor;
active heat preservation technology of the tunnel is paid more attention and developed in recent years, active heat preservation refers to artificially providing a heat source to the inside of the tunnel to achieve the purpose of reducing or eliminating the freezing of surrounding rocks of the tunnel, an electric heater is commonly adopted to heat a drainage ditch, and in China, the method is adopted to treat the freezing damage of the tunnel in the quasitum tunnel.
However, the cold-proof effect of laying the heat supply pipe in a small range in the tunnel in the cold region is limited, the heat supply pipe laid in a large range can influence the lining structure, the later maintenance of the heat supply device is complicated, and if cold natural wind can be actively blocked to enter the tunnel at the entrance and the exit of the tunnel, the freezing injury can be radically eliminated, so that a novel active heat preservation technology capable of fundamentally solving the freezing injury problem of the tunnel in the cold region is developed, and the cold-proof heat preservation device has important innovative significance and application value.
Generally, the longitudinal temperature field distribution of the tunnel in the cold region is a parabola shape with a high middle part and a low inlet, the opening sections at two ends are most prone to freeze damage, and if the temperature of the opening sections of the tunnel is effectively controlled, the occurrence of the freeze damage can be prevented.
Therefore, an air curtain thermal insulation model test system and a test method thereof need to be developed to verify the feasibility of the air curtain thermal insulation technology of the tunnel in the cold region.
Disclosure of Invention
The invention provides an air curtain heat preservation model test system and a test method thereof.
The invention adopts the following technical scheme:
in one aspect, the present invention provides an air curtain thermal insulation model test system, comprising:
the shed tunnel model is used for simulating an external shed tunnel at the front end of the tunnel main body;
the environment system is used for adjusting the environment temperature and the wind parameters of the shed tunnel model;
the air curtain system is arranged at the top end of the shed tunnel model and used for simulating different jet flow wind speeds and jet flow angles of air in the shed tunnel model;
a test system coupled to the environmental system and the air curtain system for performing a system test.
Further, the environmental system includes freezer, fan and anemoscope, the freezer the fan with the anemoscope all connect in test system, freezer are used for simulating the cold natural condition in the tunnel outside, the shed tunnel model the fan with the anemoscope all sets up in the freezer, the fan sets up the front end of shed tunnel model is in order to simulate natural wind, the anemoscope sets up the entry of shed tunnel model is in order to know the wind speed information of the entrance of shed tunnel model.
Further, the shed tunnel model is a pipeline with a rectangular cross section.
Furthermore, the air curtain system comprises a plurality of air curtain machines embedded at the top end of the shed tunnel model, wherein the plurality of air curtain machines are arranged at equal intervals.
Furthermore, the air curtain machine comprises an electric heating air curtain, a bell mouth, an angle regulator and an air curtain support, wherein the electric heating air curtain is fixedly arranged at the top end of the shed tunnel model through the air curtain support, the bell mouth is communicated with an exhaust port of the electric heating air curtain, and the angle regulator is arranged in the bell mouth to regulate the direction of air flow.
Further, the environmental system still includes a plurality of thermal resistance and a plurality of temperature recorder, and is a plurality of thermal resistance and a plurality of temperature recorder all connect in test system, every adjacent be equipped with one in the shed tunnel model between the air curtain machine thermal resistance with the temperature recorder, the air current import and the head end of shed tunnel model be equipped with one in the shed tunnel model between the air curtain machine thermal resistance and one the temperature recorder, the air current export and the tail end of shed tunnel model be equipped with one between the air curtain machine thermal resistance and one in the shed tunnel model.
In another aspect, the present invention provides a method for performing a test using an air curtain thermal insulation model test system, comprising:
step 1: setting the temperature of the refrigeration house to-10 ℃ through a testing system, and closing a door of the refrigeration house;
step 2: acquiring the recording data of the temperature recorder through a testing system, and adjusting an angle adjuster to adjust the jet angle of the air curtain machine after the testing temperature is reached;
and 3, step 3: adjusting the position of an air curtain machine, opening an air curtain, adjusting the jet flow speed of the air curtain and closing a door of the refrigeration house;
and 5, after the test is finished, exporting the temperature data of the temperature recorder through a USB socket on the temperature recorder, and analyzing.
Compared with the prior art, the invention has the following advantages:
1. compared with the original heat insulation layer method, the air curtain heat insulation technology can be actively isolated, external cold air flow is simulated, the temperature of the air flow entering the tunnel is enabled to be above 0 ℃, and the air curtain heat insulation method has a good test effect.
2. Along with the increase of tunnel live time, or receive the influence of groundwater in the stratum, the heat preservation effect of heat preservation can reduce, and it is hard to waste time to change the heat preservation, and air curtain heat preservation technique is then convenient dismantlement and maintenance.
Drawings
FIG. 1 is a schematic diagram of a shed tunnel model in an embodiment of the invention;
FIG. 2 is a schematic diagram of a region dividing the shed tunnel model according to an embodiment of the present invention;
FIG. 3 is a schematic view of an air curtain machine according to an embodiment of the present invention.
In the figure, 1-shed tunnel model, 2-air curtain system, 21-air curtain machine, 211-electric heating air curtain, 212-bell mouth, 213-angle regulator and 214-air curtain support.
Detailed Description
In order that the above objects, features and advantages of the present invention can be more clearly understood, the present invention will be described in further detail below with reference to the accompanying drawings and specific embodiments, it being understood that the embodiments and features of the embodiments of the present application can be combined with each other without conflict.
Examples
As shown in fig. 1, the air curtain heat preservation model test system is built according to the similarity principle, the similarity ratio of the air curtain heat preservation model test system to an actual tunnel is 1:
the shed tunnel model 1 is used for simulating an external shed tunnel at the front end of the tunnel main body;
an environmental system (not shown) for adjusting the ambient temperature and wind parameters of the shed tunnel model;
the air curtain system 2 is arranged at the top end of the shed tunnel model 1 and used for simulating different jet flow wind speeds and jet flow angles of air in the shed tunnel model 1;
a test system (not shown) connected to the environmental system and the air curtain system 2 for performing system tests.
In the actual test process, the shed tunnel model 1 is used for simulating a rectangular shed tunnel built at the front end of a tunnel, and the rectangular shed tunnel is built at the front end of the tunnel because the cross section of the tunnel is horseshoe-shaped and is not beneficial to arranging an air curtain;
in the embodiment, the shed tunnel model 1 is a pipeline with a rectangular cross section, and is assembled by adopting an organic glass plate with the thickness of 1.5cm, and the organic glass plate is provided with a screw hole and is connected with a sealing strip through a 3mm stainless steel bend, an M6 bolt, an organic glass flange;
the length, the width and the height of the shed tunnel model 1 are respectively 4.75m, 1.5m and 1m, and the sizes of the corresponding actual tunnel sections are 38m, 12m and 8m;
the test system is mainly used for controlling the environment system and the air curtain system 2 to realize the simulation of the climate in the cold region, wherein the test system can adopt a programmable logic controller;
in addition, in order to realize accurate simulation of the climate in the cold region, the air curtain thermal insulation model test system further comprises a climate parameter collecting device (not shown) connected with the test system, for example, the climate parameter collecting device comprises a humidity sensor and a pressure sensor;
the environment system comprises a refrigeration house, a fan and an anemoscope, wherein the refrigeration house, the fan and the anemoscope are all connected to the test system, the refrigeration house is used for simulating cold natural conditions outside a tunnel, the shed tunnel model 1, the fan and the anemoscope are all arranged in the refrigeration house, the fan is arranged at the front end of the shed tunnel model 1 to simulate natural wind, and the anemoscope is arranged at the inlet of the shed tunnel model 1 to acquire wind speed information at the inlet of the shed tunnel model;
in the embodiment, the length, the width and the height of the refrigeration house are respectively 6.6m, 2.1m and 1.9m, a key on a door of the refrigeration house can control the refrigeration temperature of the refrigeration house in a stepless manner, the temperature control range is 0-minus 30 ℃, the external air temperature in winter can be simulated, and the refrigeration house can be also controlled remotely through the test system;
the height of the fan is 1m, the fan is the same as that of the shed tunnel model 1, the fan can be regulated and controlled in a stepless mode through a knob installed on site, the speed of an outlet of the fan can reach 6m/s at most, and the fan is placed at the front end of the shed tunnel model and can simulate the external natural wind speed;
and the anemoscope is used for testing the wind speed at the inlet of the shed tunnel model 1.
The air curtain system 2 comprises a plurality of air curtain machines 21 embedded at the top end of the shed tunnel model 1, wherein the air curtain machines 21 are arranged at equal intervals;
as shown in fig. 3, the air curtain machine 21 includes an electric heating air curtain 211, a bellmouth 212, an angle adjuster 213 and an air curtain bracket 214, wherein the electric heating air curtain 211 is fixedly disposed at the top end of the shed tunnel model 1 through the air curtain bracket 214, the bellmouth 212 is communicated with an exhaust port of the electric heating air curtain 211, and the angle adjuster 213 is disposed in the bellmouth 212 to adjust an air flow direction.
In the actual test process, the test researches show that when the external temperature is higher than-10 ℃,1 air curtain machine 21 can meet the heating requirement, but when the external temperature is very low, such as-20 ℃, two air curtain machines 21 are required to be connected in series to heat the air entering the tunnel, and if the temperature is lower, the air curtain machines are continuously connected in series, and so on; therefore, in the above embodiment, several air curtains can be controlled separately;
in the above embodiment, the air curtain system 2 comprises 4 air curtains 21 embedded at the top end of the shed tunnel model, 4 air curtains 21 are equidistantly arranged to divide the area of the shed tunnel model into 5 mutually adjacent sub-areas, and each sub-area is provided with a lead-type thermal resistor (model: MIK-WZP) and a temperature recorder (model: MIK-R200T) connected with the test system;
as shown in fig. 2, the 5 adjacent subregions include three regions: the temperature recorder is arranged at the tail end of the shed tunnel model 1 for the purpose of knowing whether the temperature of the air flow entering the tunnel reaches above 0 ℃.
The method for testing by using the air curtain heat preservation model test system comprises the following steps:
step 1: setting the temperature of the refrigeration house to-10 ℃ through a testing system, and closing a door of the refrigeration house;
step 2: acquiring the recording data of the temperature recorder through a testing system, and adjusting an angle adjuster to adjust the jet angle of the air curtain after the testing temperature is reached;
and 3, step 3: adjusting the position of an air curtain machine 21, opening an air curtain, adjusting the jet flow speed of the air curtain and closing a door of the refrigeration house;
and 5, after the test is finished, exporting the temperature data of the temperature recorder through a USB socket on the temperature recorder, and analyzing.
In step 3 of the above embodiment, specifically, the air curtain system 2 is placed at the position of 0.6m of the depth of the shed tunnel model 1 (corresponding to the actual object system being at the position of 4.8m of the depth of the shed tunnel), the air curtain machine 21 is opened through the test system, the jet flow speed of the air curtain machine 21 is adjusted, the air curtain machine leaves the refrigerator, the door of the refrigerator is closed, the jet flow angle of the air curtain machine 21 is set to be 30 degrees, and experiments prove that the optimal jet flow angle of the air curtain is 30 degrees;
in step 5 of the above embodiment, the derived data are temperature data of 5 temperature recorders and power data of 5 lead-wire thermal resistors, wherein the temperature recorder of the region in the shed tunnel model 1 between the air inlet of the shed tunnel model 1 and the air curtain 21 at the head end represents the temperature of the air entering the tunnel, and if the temperature is higher than 0 ℃, the temperature data represents that the tunnel cannot be frozen in winter.
Because the shed tunnel model 1 is developed through similar theory derivation, the final determination is that the geometric similarity ratio of the shed tunnel model 1 to a real object is 1; the speed similarity ratio of the shed tunnel model 1 to the real object is 1.
Temperature change data of the measured points on the temperature recorder of the area in the shed tunnel model 1 between the air flow inlet of the shed tunnel model 1 and the air curtain 21 at the head end when the temperature of the refrigeration house is-10 ℃ and the air curtain jet angle is 30 ℃ are given as follows.
Test value of measuring point at jet angle of 30 DEG
It can be seen that the temperature of the air finally entering the tunnel after 114s is above 0 ℃, and the temperature of the air flow entering the tunnel after 210s is 7.79 ℃, so that the freezing injury in the tunnel can be eliminated.
The present invention is not limited to the above-described embodiments, which are described in the specification and illustrated only for illustrating the principle of the present invention, but various changes and modifications may be made within the scope of the present invention as claimed without departing from the spirit and scope of the present invention. The scope of the invention is defined by the appended claims.
Claims (10)
1. An air curtain heat preservation model test system is characterized by comprising:
the shed tunnel model is used for simulating an external shed tunnel at the front end of the tunnel main body;
the environment system is used for adjusting the environment temperature and the wind parameters of the shed tunnel model;
the air curtain system is arranged at the top end of the shed tunnel model and used for simulating different jet flow wind speeds and jet flow angles of air in the shed tunnel model;
a test system coupled to the environmental system and the air curtain system for performing system tests.
2. The air curtain heat preservation model test system according to claim 1, characterized in that the environmental system comprises a refrigeration house, a fan and an anemoscope, the refrigeration house, the fan and the anemoscope are all connected to the test system, the refrigeration house is used for simulating the cold natural conditions outside the tunnel, the shed tunnel model, the fan and the anemoscope are all arranged in the refrigeration house, the fan is arranged at the front end of the shed tunnel model to simulate natural wind, and the anemoscope is arranged at the inlet of the shed tunnel model to acquire wind speed information at the inlet of the shed tunnel model.
3. The air curtain thermal insulation model test system of claim 1, wherein the shed tunnel model is a pipe with a rectangular cross section.
4. The air curtain thermal insulation model test system as claimed in claim 1 or 3, wherein the air curtain system comprises a plurality of air curtain machines embedded at the top end of the shed tunnel model, wherein the plurality of air curtain machines are arranged at equal intervals.
5. The air curtain thermal insulation model test system as claimed in claim 4, wherein the air curtain machine comprises an electric heating air curtain, a bell mouth, an angle adjuster and an air curtain bracket, the electric heating air curtain is fixedly arranged at the top end of the shed tunnel model through the air curtain bracket, the bell mouth is communicated with an exhaust port of the electric heating air curtain, and the angle adjuster is arranged in the bell mouth to adjust the air flow direction.
6. The air curtain thermal insulation model test system as claimed in claim 4, wherein the environmental system further comprises a plurality of thermal resistors and a plurality of temperature recorders, the plurality of thermal resistors and the plurality of temperature recorders are connected to the test system, one thermal resistor and one temperature recorder are provided in a shed tunnel model between each adjacent air curtain, one thermal resistor and one temperature recorder are provided in a shed tunnel model between an airflow inlet of the shed tunnel model and an air curtain at the head end, and one thermal resistor and one temperature recorder are provided in a shed tunnel model between an airflow outlet of the shed tunnel model and an air curtain at the tail end.
7. A method for testing by using an air curtain heat preservation model test system is characterized by comprising the following steps:
step 1: setting the temperature of the refrigeration house to-10 ℃ through a testing system, and closing a door of the refrigeration house;
step 2: acquiring the recording data of the temperature recorder through a testing system, and adjusting an angle adjuster to adjust the jet angle of the air curtain after the testing temperature is reached;
and step 3: adjusting the position of an air curtain machine, opening an air curtain, adjusting the jet flow speed of the air curtain and closing a door of the refrigeration house;
step 4, setting the recording interval of the temperature recorders to be 1s, observing the temperatures displayed by all the temperature recorders, closing an air curtain machine in the cold storage when the temperature in the shed tunnel model box reaches more than 0 ℃, and finishing one test;
and 5, after the test is finished, exporting the data through a USB (universal serial bus) socket on the temperature recorder, and analyzing.
8. The method for testing by using an air curtain thermal insulation model test system as claimed in claim 7, wherein the derived data in step 5 comprises temperature data of a temperature recorder.
9. The method for testing by using the air curtain thermal insulation model test system according to claim 7 or 8, wherein the step 5 further comprises: collecting the output power of the thermal resistor; the opening number of the air curtains and the total output power of the opened air curtains are collected.
10. The method for testing by using the air curtain thermal insulation model test system as claimed in claim 9, wherein the step 5 further comprises: the method comprises the steps of collecting the refrigeration power of a refrigeration house, collecting the output power of a fan and collecting the wind speed of an anemoscope.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210878679.9A CN115326867A (en) | 2022-07-25 | 2022-07-25 | Air curtain heat preservation model test system and test method thereof |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210878679.9A CN115326867A (en) | 2022-07-25 | 2022-07-25 | Air curtain heat preservation model test system and test method thereof |
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| CN115326867A true CN115326867A (en) | 2022-11-11 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN202210878679.9A Pending CN115326867A (en) | 2022-07-25 | 2022-07-25 | Air curtain heat preservation model test system and test method thereof |
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- 2022-07-25 CN CN202210878679.9A patent/CN115326867A/en active Pending
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