1. The utility model provides a test device for rain and snow load coupling simulation, characterized by: the device comprises: rain system, water supply system, control system, snow blowing system and vibration snowfall system, control system control water supply system supplies water to rain system, blows the snow system and directly generates the snow granule under low temperature environment, and the device is broadcast through the vibration to the vibration snowfall system, broadcasts snow in the test segment for simulate sky snowfall.

2. A test device for rain and snow load coupling simulation according to claim 1, wherein: the control system adopts an electromagnetic valve, the rain system comprises a rainfall nozzle and a rainfall frame, the water supply system comprises a water tank, a booster water pump and a flow regulating valve, a water inlet pipeline of the water tank is connected with the booster water pump, a water return pipeline of the booster water pump is connected with the flow regulating valve, and a water return pipeline of the flow regulating valve is connected with the water tank;

and a water inlet pipeline of the booster water pump is connected with an electromagnetic valve, and the electromagnetic valve is connected with a rainfall nozzle.

3. A test device for rain and snow load coupling simulation according to claim 2, wherein: the snow blowing system adopts a nucleon device, a snow blowing frame and a snow making machine, the snow blowing frame and the nucleon device are connected with a water inlet pipeline of a booster water pump, the atomized water output end of the nucleon device is connected with the snow blowing frame, and snow particles are output to the vibration snow falling system by a snow particle conveying path of the snow making machine.

4. A test device for rain and snow load coupling simulation according to claim 3, wherein: the electromagnetic valve comprises a first electromagnetic valve, a second electromagnetic valve and a third electromagnetic valve, the first electromagnetic valve is connected with a light rain simulation water pipeline, the second electromagnetic valve is connected with a medium rain simulation water pipeline, and the third electromagnetic valve is connected with a heavy rain simulation water pipeline.

5. A test device for rain and snow load coupling simulation according to claim 4, wherein: the device also comprises an air compressor, wherein the air supply end of the air compressor is connected with the nuclear device, and the air compressor is used for drying the nozzles and the water in the pipeline.

6. A test device for rain and snow load coupling simulation according to claim 3, wherein: the device also comprises a softening device, wherein water in the water tank is filtered by the filter and softened by the softening device.

7. A test device for rain and snow load coupling simulation according to claim 3, wherein: the snow blowing frame comprises an air switch valve, an air filter, an air regulator, a pressure gauge, an air atomizing nozzle, a hydraulic regulator, a pressure gauge, a liquid filter and a liquid switch valve;

air passes through an air switch valve which is connected with an air filter, the air filter is connected with an air regulator and a pressure gauge, the air regulator and the pressure gauge are connected with an air atomizing nozzle,

the liquid enters a liquid switch valve, the liquid switch valve is connected with a liquid filter, the liquid filter is connected with a liquid pressure regulator and a pressure gauge, and the liquid pressure regulator and the pressure gauge are connected with an air atomizing nozzle.

Background

Global extreme low temperature ice and snow disasters frequently occur, collapse accidents of buildings and structures caused by snow accumulation are increased continuously, and the snow resistance form of the building structure is very severe. Taking our country as an example, statistics are reported that in 2015, 11 months and in the middle of our country, big snow is generally fallen, and many provinces have snow to cause house collapse accidents, so that more than one thousand houses are damaged; in 1 month of 2018, the house collapses in more than 400 rooms and is damaged in more than 1900 rooms due to two large snow in the middle. Similar accidents are also frequent in japan, the united states, canada, and norway. In engineering disasters caused by nearly hundreds of snow, which occur at home and abroad since 2008, large-span space structures (25% of net rack net shells and 18% of space trusses), steel cantilever structures, light steel structures and other structures sensitive to snow load are more. The large-span space structure has the characteristics of light roof structure, large roof area and large proportion of snow load to total load, is usually controlled by snow load, and belongs to a structure sensitive to the snow load. On the other hand, the large-span space structure is mostly applied to public buildings such as stadiums, airport terminals, railway stations, and the like, which are very dense in personnel and have a great influence, so that the engineering disaster result caused by snow of the large-span space structure is very serious, and the design method for correctly mastering the roof snow load is of great significance. The project aims to develop an internationally leading wind-rain-heat-snow overall process combined simulation test system with a large-span space structure, and the system consists of five subsystems, namely an atmospheric boundary layer low-temperature wind tunnel, snowfall simulation, rainfall simulation, solar radiation and building heat supply simulation and high-precision multi-task monitoring and control. The system development provides an irreplaceable test platform for deeply disclosing the evolution mechanism of the whole process of the snow on the roof under the wind-rain-heat-snow coupling action of the large-span space structure, simultaneously provides a reliable basis for perfecting numerical simulation research on the snow load on the roof, and also provides a powerful support for the high point of the research theory of preempting the snow load on the building in China.

A large number of post-disaster investigation results show that: the understanding of the accumulation mechanism and the change rule of the roof snow is unclear, and particularly, the understanding of the whole process mechanism of accumulation-ablation-crystallization-accumulation evolution of the roof snow under the influence of environmental factors such as wind, rain, heat and the like is almost blank and becomes the most fundamental cause of disasters. Therefore, only by comprehensively mastering the mechanism of accumulated snow on the roof, the roof snow load can be comprehensively known and correctly designed, and the safety and reliability of the structure are ensured from the source. At present, there are three methods for snow load research, which are field actual measurement, wind tunnel test and numerical simulation. The field actual measurement is limited by climate and measurement conditions, the work progress is slow, and the basic data is very deficient. The numerical simulation is low in cost and short in design period, but lacks support of actual measurement and experimental data and a unified standard. At present, wind tunnel test is a main means for studying snow load by Chinese and foreign students, but when the existing wind tunnels (traditional wind tunnel, French JV meteorological wind tunnel, Japanese New village CES wind tunnel, Harmony big wind and snow combined test system and the like) are applied for testing, the problems that the mechanism of roof snow accumulation is simulated, and especially the rain and snow load coupling simulation is incomplete exist: (1) the distribution of accumulated snow or ice on the building roof in rainy and snowy weather cannot be simulated; (2) the influence of rainfall on the existing accumulated snow cannot be researched, and the whole process of the evolution of the roof snow load in a complex environment cannot be simulated.

Disclosure of Invention

The invention simulates the distribution of accumulated snow or ice on the building roof in rainy and snowy weather; and secondly, the influence of rainfall on the existing accumulated snow is researched, and the whole process of the evolution of the roof snow load in a complex environment is simulated. The invention provides a test device for rain and snow load coupling simulation, which provides the following technical scheme:

a test device for rain and snow load coupling simulation, the device comprising: rain system, water supply system, control system, snow blowing system and vibration snowfall system, control system control water supply system supplies water to rain system, blows the snow system and directly generates the snow granule under low temperature environment, and the device is broadcast through the vibration to the vibration snowfall system, broadcasts snow in the test segment for simulate sky snowfall.

Preferably, the control system adopts an electromagnetic valve, the rain system comprises a rainfall nozzle and a rainfall frame, the water supply system comprises a water tank, a booster water pump and a flow regulating valve, a water inlet pipeline of the water tank is connected with the booster water pump, a water return pipeline of the booster water pump is connected with the flow regulating valve, and a water return pipeline of the flow regulating valve is connected with the water tank;

and a water inlet pipeline of the booster water pump is connected with an electromagnetic valve, and the electromagnetic valve is connected with a rainfall nozzle.

Preferably, the snow blowing system adopts a nucleon, a snow blowing frame and a snow making machine, the snow blowing frame and the nucleon are connected with a water inlet pipeline of a booster water pump, an atomized water output end of the nucleon is connected with the snow blowing frame, and a snow particle conveying path of the snow making machine outputs snow particles to the vibration snow falling system.

Preferably, the solenoid valves include a first solenoid valve, a second solenoid valve and a third solenoid valve, the first solenoid valve is connected to the light rain simulation water pipeline, the second solenoid valve is connected to the medium rain simulation water pipeline, and the third solenoid valve is connected to the heavy rain simulation water pipeline.

Preferably, the device further comprises an air compressor, the air supply end of the air compressor is connected with the nuclear device, and the air compressor is used for drying the nozzles and the water in the pipeline.

Preferably, the device further comprises a softening device, wherein the water in the water tank is filtered by the filter and passes through the softening device to soften the water source.

Preferably, the snow blowing frame comprises an air switch valve, an air filter, an air regulator, a pressure gauge, an air atomizing nozzle, a hydraulic regulator, a pressure gauge, a liquid filter and a liquid switch valve;

air passes through an air switch valve which is connected with an air filter, the air filter is connected with an air regulator and a pressure gauge, the air regulator and the pressure gauge are connected with an air atomizing nozzle,

the liquid enters a liquid switch valve, the liquid switch valve is connected with a liquid filter, the liquid filter is connected with a liquid pressure regulator and a pressure gauge, and the liquid pressure regulator and the pressure gauge are connected with an air atomizing nozzle.

The invention has the following beneficial effects:

the invention fully considers the evolution process of the ice and snow load of the roof caused by rainfall. The method provides important support for the simulation research of the whole process of accumulated snow accumulation-ablation-crystallization-accumulation evolution of the large-span spatial structure roof. The existing ice and snow environment simulator usually adopts a high-pressure spray gun or a linear single-layer vibration spreading device to simulate a snowing environment, and the uniformity of particle spreading has a great problem. Therefore, the wind snow blowing device adopts a nuclear device, firstly an atomizing environment is formed in a test section, then the snow blowing module of the upstream snow blowing frame is used for horizontally blowing snow, and the snow is cooled and condensed by low-temperature high-speed airflow to form uniform and stable snow particle inflow. The vibration scattering device adopts a planar double-layer screen, particles are primarily and uniformly scattered on the two layers of screens through left-right vibration screening of the first layer of screen, and then the particles are uniformly scattered through up-down vibration.

The rainfall system adopts double-precision regulation, namely, flow restriction is realized through flow control, and pressure is regulated within a reasonable flow restriction range, so that the water condition provided by the water supply system is well matched with the water condition required by the work of the rainfall nozzle, continuous, uniform and stable rainfall coverage can be realized, and a good rainfall simulation effect is achieved. The equipment is provided with a high-sensitivity electronic rain gauge and a rain amount microcomputer collector, the whole rainfall process is controlled by adjusting the actual rainfall parameters of the terminal, the dynamic change and curve of the simulated rainfall can be displayed in real time, and errors caused by loss and resistance of each link from a water source to a nozzle are effectively overcome.

Drawings

FIG. 1 is a schematic view of a test device for simulating rain and snow load coupling;

FIG. 2 is a view of the structure of a snow blowing frame;

fig. 3 is a diagram showing a configuration of a rainfall system.

Detailed Description

The present invention will be described in detail with reference to specific examples.

The first embodiment is as follows:

according to fig. 1 to 3, the present invention provides a test device for a rain and snow load coupling simulation, the device comprising: rain system, water supply system, control system, snow blowing system and vibration snowfall system, control system control water supply system supplies water to rain system, blows the snow system and directly generates the snow granule under low temperature environment, and the device is broadcast through the vibration to the vibration snowfall system, broadcasts snow in the test segment for simulate sky snowfall.

The snow blowing system can directly generate snow particles in a low-temperature environment and is used for a snow blowing test; the vibration snowfall system can spread snow prepared in advance in a test section through the vibration spreading device so as to simulate the snowfall in the sky.

The rain system is used for simulating natural rainfall; the water supply system provides a water source for the system, and ensures the water quality and quantity of supplied water; the control system realizes the regulation of the rain intensity, monitors and realizes the closed-loop control of the whole system. The main working equipment consists of a centrifugal pump, a frequency converter, a rainfall nozzle, a pressure transmitter, a flowmeter, an electronic rain gauge, a water supply pipeline, a square steel bracket and the like.

The working process and the working principle of the invention are as follows: when snow is produced, tap water is pretreated first and then subjected to secondary reverse osmosis and Electrodeionization (EDI) to meet the spray water index. The pure water is electrically heated to 40 ℃, and is sent to a nozzle on a spraying device by a metering pump at the working pressure of 0-0.5 MPa for use. In order to prevent the water entering the spraying system from being overheated, the cold water in the ultrapure water tank is mixed with the hot water in the electric heating water tank, and then the mixture is fed into the spraying rake through the metering pump, so that the aim of reducing the water temperature is fulfilled. In addition, the equipment is provided with a water return pipeline, and the design of the device for spreading the snowfall by returning the return water of the spray rake and the redundant water from the metering pump to the water tank through a fine adjustment valve pipeline is mainly used for ensuring the uniformity of the snowfall. In the past, a single-layer bar-shaped vibration scattering device is adopted in the test, the particle scattering uniformity has a great problem, in order to ensure the uniformity of snowfall, the vibration scattering device of the test system adopts a planar double-layer screen, the first layer screen is subjected to left-right vibration screening, so that particles are primarily and uniformly scattered on the second layer screen, and then the particles are uniformly scattered through up-down vibration.

The rainfall coverage area and the rainfall intensity are used as core parameters, the water supply system adopts water pressure and water quantity double-stage fine adjustment, the water flow data of the flow meter is used as main control feedback, and finally accurate and uniform coverage of the rainfall intensity in a test area is achieved.

The control system adopts an electromagnetic valve, the rain system comprises a rainfall nozzle and a rainfall frame, the water supply system comprises a water tank, a booster water pump and a flow regulating valve, a water inlet pipeline of the water tank is connected with the booster water pump, a water return pipeline of the booster water pump is connected with the flow regulating valve, and a water return pipeline of the flow regulating valve is connected with the water tank;

and a water inlet pipeline of the booster water pump is connected with an electromagnetic valve, and the electromagnetic valve is connected with a rainfall nozzle.

The snow blowing system adopts a nucleon device, a snow blowing frame and a snow making machine, the snow blowing frame and the nucleon device are connected with a water inlet pipeline of a booster water pump, the atomized water output end of the nucleon device is connected with the snow blowing frame, and snow particles are output to the vibration snow falling system by a snow particle conveying path of the snow making machine.

The electromagnetic valve comprises a first electromagnetic valve, a second electromagnetic valve and a third electromagnetic valve, the first electromagnetic valve is connected with a light rain simulation water pipeline, the second electromagnetic valve is connected with a medium rain simulation water pipeline, and the third electromagnetic valve is connected with a heavy rain simulation water pipeline.

The device also comprises an air compressor, wherein the air supply end of the air compressor is connected with the nuclear device, and the air compressor is used for drying the nozzles and the water in the pipeline.

The device also comprises a softening device, wherein water in the water tank is filtered by the filter and softened by the softening device.

The snow blowing frame comprises an air switch valve, an air filter, an air regulator, a pressure gauge, an air atomizing nozzle, a hydraulic regulator, a pressure gauge, a liquid filter and a liquid switch valve;

air passes through an air switch valve which is connected with an air filter, the air filter is connected with an air regulator and a pressure gauge, the air regulator and the pressure gauge are connected with an air atomizing nozzle,

the liquid enters a liquid switch valve, the liquid switch valve is connected with a liquid filter, the liquid filter is connected with a liquid pressure regulator and a pressure gauge, and the liquid pressure regulator and the pressure gauge are connected with an air atomizing nozzle.

During the snow blowing test, the snow blowing module is arranged at the nozzle of the test section to blow snow horizontally, and the snow blowing module and the nozzle are connected and fixed by flanges. When a snow blowing test is started, test water is provided by a water treatment center, the test water is pressurized by a booster pump and then is conveyed to a snow blowing frame through a high-pressure hose, the snow blowing frame firstly starts a nucleon device to form an atomizing environment, then the water supply amount provided by a booster water pump is adjusted according to a preset program on a control panel, the small liquid drops are forced to perform heat exchange with cold air in the test environment through high-speed airflow provided by a wind tunnel fan, and the small liquid drops are cooled and crystallized to form test snowfall.

During the snowfall test, the stored quantitative snow is adopted for carrying out the simulation test, and the snow crystal particles can uniformly fall to the test section by utilizing the spreading device, so that the snowfall simulation is completed. The vibration sowing device consists of a vibration controller, a vibration disc (comprising a feeding hopper) and two layers of screens, wherein the vibration controller can control the feeding speed by adjusting the vibration frequency. The pulse electromagnet is arranged below the vibrating disc hopper, so that the hopper can vibrate in the vertical direction, and the inclined spring piece drives the hopper to do torsional vibration around the vertical shaft of the hopper. The particles in the hopper rise along the spiral track due to vibration, and are screened or changed in posture through a series of tracks in the rising process, so that the particles can automatically enter the screening device in a uniform state as required. First layer screen cloth chooses for use the net aperture size great, and the primary selection is 2 times in second floor net aperture, rocks about through the control screen cloth to make snow brilliant granule drip to second floor net top, and basically can evenly distributed, the vertical vibration of rethread second floor screen cloth makes snow brilliant granule can evenly fall to the test section, thereby accomplishes the simulation of snowing.

The power supply frequency of a water pump motor is controlled based on a PLC programming frequency converter, the rainfall is regulated through flow control and pressure control, the rainfall intensity is stabilized, and a professional rainfall nozzle spraying mode is adopted for rainfall simulation. Firstly, a water supply center provides a water source which is filtered by a filter and softened by a softening device, a variable frequency water pump conveys softened water, a flow regulating valve is adopted to regulate the flow of a branch pipeline, and a flowmeter is utilized to monitor the flow of a main pipeline, so that the flow regulation of a system is realized. The pressure of the pipeline is controlled by the pressure regulating valve, so that the pressure at the nozzle end reaches a working pressure state. And the opening and the closing of the nozzle end pipeline are controlled by a solenoid valve. After the test is finished, in order to avoid icing and blocking and rusting of the pipeline, residual water in the pipeline needs to be discharged, and therefore, a compressed air scavenging device is adopted to blow dry the nozzle and water in the nearby pipeline.

The technical indexes which can be achieved by the test device for simulating the rain and snow load coupling provided by the invention are as follows: 1) the wind snow blowing device can realize uniform particle scattering in the test section and ensure the uniformity of the wind snow blowing environment; 2) the snow blowing intensity is 30-150mm/h, and the snow blowing environment from small snow to snowstorm can be truly simulated; 3) the snow blowing area is 2m multiplied by 1.5m, large-area spreading can be realized, and the feasibility of a large-scale-ratio model test is ensured; 4) the snowing device can realize uniform spreading of snow particles through the arrangement of the double-layer screen; 5) the snowfall strength can simulate the snowfall environment under natural conditions from small snow to snowstorm, and the snowfall area is 2m x 5 m. 6) Rainfall intensity: 5-120 mm/24h (+/-2 mm/24h), and is adjustable; 7) rain uniformity in windless conditions: is more than 0.7; 8) the rainfall area reaches 2m multiplied by 6 m; 9) continuous rainfall time: 1 h; 10) the control system realizes the regulation of the rainfall intensity, carries out real-time monitoring and realizes the closed-loop control of the whole rainfall subsystem.

The above description is only a preferred embodiment of the test device for simulating rain and snow load coupling, and the protection scope of the test device for simulating rain and snow load coupling is not limited to the above embodiments, and all technical solutions belonging to the idea belong to the protection scope of the present invention. It should be noted that modifications and variations which do not depart from the gist of the invention will be those skilled in the art to which the invention pertains and which are intended to be within the scope of the invention.