CN118082457A - CFD thermal comfort analysis method based on PLC200 temperature acquisition system - Google Patents
CFD thermal comfort analysis method based on PLC200 temperature acquisition system Download PDFInfo
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Abstract
The invention relates to the field of automobile air conditioners, in particular to an automobile air conditioner heating thermal comfort analysis method, and particularly relates to a PLC200 temperature acquisition analysis method using two thermal comfort evaluation indexes of PMV-PPD and EQT. The invention provides a method for acquiring in-vehicle thermal flow fields by PLC200 data and comparing the data with Star-CCM+ output data, and calculating average voting Prediction (PMV), prediction dissatisfaction percentage (PPD) and equivalent temperature (EQT). The method analyzes the temperature rising effect, the distribution of the hot-wet flow field, the uniformity of the hot flow field and the thermal comfort of the human body of the air conditioner in the passenger cabin, improves the direction of the air conditioner, reduces the power consumption and improves the endurance mileage.
Description
Technical Field
The invention relates to the field of automobile air conditioners, in particular to a heating thermal comfort analysis method of an automobile air conditioner.
Background
The automobile adjusts the thermal environment in the passenger compartment by means of an automobile air conditioner. The automobile air conditioner regulates the in-cabin thermal flow field, improves the thermal comfort level of human bodies, provides defrosting and defogging functions for windshields and windows, and greatly improves the driving safety. The air outlet temperature is reasonably regulated, and the functions of reducing energy consumption and improving endurance mileage are realized on the premise of ensuring the thermal comfort of a human body. At present, no method for rapidly analyzing the thermal comfort of passengers by using two evaluation indexes of PMV-PPD and EQT based on experimental combination simulation is disclosed.
Disclosure of Invention
The invention aims to provide a CFD thermal comfort analysis method based on a PLC200 temperature acquisition system, which is used for carrying out numerical simulation on the thermal comfort of passengers in a cabin and analyzing 4 angles of the heating effect of an automobile air conditioner in the cabin of the passengers, the distribution of hot-wet flow fields in the cabin, the uniformity of the hot flow fields and the thermal comfort of a human body, so as to evaluate the environment of a hot flow field in the cabin.
In order to achieve the above purpose, one embodiment of the present invention provides a CFD thermal comfort analysis method based on a PLC200 temperature acquisition system, including a temperature detection network, a PLC200 automatic control host, a signal transmission networking and a new energy automobile cabin air conditioning system;
The temperature detection network comprises a first four-hole aviation male plug, a second four-hole aviation male plug, a third four-hole aviation male plug, a fourth four-hole aviation male plug, a fifth four-hole aviation male plug, a sixth four-hole aviation male plug, a seventh four-hole aviation male plug, an eighth four-hole aviation male plug, a ninth four-hole aviation male plug, a fourteenth four-hole aviation male plug, an eleventh four-hole aviation male plug, a twelfth four-hole aviation male plug, a thirteenth four-hole aviation male plug, a fourteenth four-hole aviation male plug, a fourth hole aviation male plug, a sixteenth four-hole aviation male plug, an eighteenth four-hole aviation male plug, a nineteenth four-hole aviation male plug and a twenty-fourth hole aviation male plug;
The PLC200 automatic control host comprises a first air circuit breaker, a first guide rail switching power supply, a first PLC200 central processor, a first PLC200 thermal resistance analog input module, a second PLC200 thermal resistance analog input module, a third PLC200 thermal resistance analog input module, a fourth PLC200 thermal resistance analog input module and a fifth PLC200 thermal resistance analog input module; the system comprises a first self-control host multi-signal power meter, a second self-control host multi-signal power meter, a first industrial touch screen, a first fan, a second fan, a first guide rail and a second guide rail;
The signal transmission networking comprises a first PLC200 industrial Ethernet communication module, a first 8-pin RJ45 cable, a first I/O expansion cable and a first small portable gateway;
The first four-hole aviation male plug, the second four-hole aviation male plug, the third four-hole aviation male plug, the fourth four-hole aviation male plug, the fifth four-hole aviation male plug, the sixth four-hole aviation male plug, the seventh four-hole aviation male plug, the eighth four-hole aviation male plug, the ninth four-hole aviation male plug, the fourteenth hole aviation male plug, the eleventh four-hole aviation male plug and the twelfth four-hole aviation male plug are respectively located at the upper part of the C surface of the PLC200 automatic control host. The thirteenth four-hole aviation male plug, the fourteenth four-hole aviation male plug, the fifteenth four-hole aviation male plug, the sixteenth four-hole aviation male plug, the seventeenth four-hole aviation male plug, the eighteenth four-hole aviation male plug, the nineteenth four-hole aviation male plug and the twenty fourth-hole aviation male plug are positioned at the lower part of the C surface of the PLC200 automatic control host, and 4 five-hole aviation male plug interfaces are reserved, so that the expansion is facilitated. The aviation female plug can be matched with thermal resistance sensors with different types and different resistance values for use, such as PT100, PT1000 and the like, so that the requirements of occasions with different precision are met. The total 24 aviation male plugs are distributed in two rows in a crossing way, the circle centers of the horizontal plugs are 3cm away, the circle centers of the vertical plugs are 3cm away, and the angle is 60 degrees;
the arrangement position of the first air circuit breaker, the first guide rail switch power supply and the central processing unit of the first PLC200 is the left side of the first guide rail of the self-control host. The arrangement positions of the first PLC200 thermal resistance analog input module, the second PLC200 thermal resistance analog input module, the third PLC200 thermal resistance analog input module, the fourth PLC200 thermal resistance analog input module and the fifth PLC200 thermal resistance analog input module are second guide rails of the automatic control host; the length of the guide rail is 38cm, the width of the guide rail is 3.5cm, the distance between the first guide rail and the second guide rail is 15cm, the distance between the modules is more than 0.5cm, heat accumulation is avoided, and an air channel is reserved.
The first automatic control host computer multi-signal power meter, the second automatic control host computer multi-signal power meter and the first industrial touch screen are arranged on the A surface of the automatic control host computer, the two multi-functional power meters are evenly distributed on the upper part, and the industrial touch screen is arranged on the lower part.
The first fan and the second fan adopt a hole digging design, are positioned on the B surface of the automatic control host machine, are used for exhausting air inwards, and adopt a circular grid to avoid damage caused by large particles entering the box body;
The CFD thermal comfort analysis method based on the PLC200 temperature acquisition system is as follows:
1) Drawing three-dimensional models of passenger cabins of different new energy automobiles by using CATIA three-dimensional modeling software, and outputting the three-dimensional models as a cabin.
2) And importing HYPERMESH the bin.stp file, dividing, selecting and renaming the surface related to the boundary condition, and dividing an air outlet and an air return opening for the entity. Partitioning Door, cabin, windows, seats, inlet, outlet; introducing HYPERMESH a dummy model, dividing the human body segment part, and dividing Head, body, arm, leg, hands, feet; assembling the dummy model, and reasonably placing the dummy model on a seat by adjusting the posture and the size of the person;
3) Carrying out surface Mesh drawing on the model by utilizing HYPERMESH self-contained Mesh function, and deriving a model. Bdf file;
4) Importing the model. Bdf file into Star-CCM+ to enter a numerical simulation calculation interface, adjusting equations, materials, boundary conditions, algorithms and file storage forms according to calculation requirements of the model, and calculating after the adjustment is completed;
5) Setting a calculation report, selecting and setting an observation point and an observation surface, and outputting a dry bulb temperature of the passenger cabin, an average radiation temperature of the passenger cabin, temperatures of different segments of a human body, relative humidity of a flow field and flow velocity of the observation surface in the flow field;
6) Editing a field function, calculating average voting Prediction (PMV), prediction dissatisfaction percentage (PPD) and equivalent temperature (EQT) by using data obtained by reporting, and analyzing the temperature rising effect of an automobile air conditioner in a passenger cabin, the distribution of a hot-wet flow field in the cabin, the uniformity of the hot flow field and the human body thermal comfort degree, which are 4 differences.
Preferably, the numerical simulation software selected for the method is Star-CCM+.
Optionally, the software for drawing the three-dimensional model is CATIA and AutoCAD drawing software.
Preferably, a human model is layered by Fiala when the human model is set in a numerical simulation calculation interface.
Preferably, upon model selection for numerical modeling, the TCM module in Star-CCM+ is invoked.
Preferably, a temperature detection network is arranged in the physical vehicle cabin, and the flow field change trend is recorded and analyzed.
Preferably, the actual vehicle cabin is compared with the three-dimensional model, and the reliability of the output data is verified.
Preferably, the Star-CCM+animation production module is called, and the variation trend of the intra-cabin hot-wet flow field is clearly observed.
The invention relates to the field of automobile air conditioners, in particular to an automobile air conditioner heating thermal comfort analysis method, and particularly relates to a PLC200 temperature acquisition analysis method using two thermal comfort evaluation indexes of PMV-PPD and EQT. The invention provides a method for acquiring in-vehicle thermal flow fields by PLC200 data and comparing the data with Star-CCM+ output data, and calculating average voting Prediction (PMV), prediction dissatisfaction percentage (PPD) and equivalent temperature (EQT). The method analyzes the temperature rising effect, the distribution of the hot-wet flow field, the uniformity of the hot flow field and the thermal comfort of the human body of the air conditioner in the passenger cabin, improves the direction of the air conditioner, reduces the power consumption and improves the endurance mileage.
Drawings
FIG. 1 is a temperature detection network of the CFD thermal comfort analysis method based on a PLC200 temperature acquisition system, which is positioned on the C side of an automatic control host computer of the PLC200 and comprises 1.1-first four-hole aviation male plug, 1.2-second four-hole aviation male plug, 1.3-third four-hole aviation male plug, 1.4-fourth four-hole aviation male plug, 1.5-fifth four-hole aviation male plug, 1.6-sixth four-hole aviation male plug, 1.7-seventh four-hole aviation male plug, 1.8-eighth four-hole aviation male plug, 1.9-ninth four-hole aviation male plug, 1.10-fourteenth four-hole aviation male plug, 1.11-eleventh four-hole aviation male plug, 1.12-twelfth four-hole aviation male plug, 1.13-thirteenth four-hole aviation male plug, 1.14-fourteenth four-hole aviation male plug, 1.15-fifteenth four-hole aviation male plug, 1.16-sixteenth four-hole aviation male plug, 1.17-seventeenth four-hole aviation male plug, 1.18-nineteenth four-hole aviation male plug and 1.18-nineteenth-fourth hole aviation male plug.
FIG. 2 is a schematic diagram of an automatic control host of a PLC200 based on a CFD thermal comfort analysis method of a PLC200 temperature acquisition system, which comprises a 2.1-first air circuit breaker, a 2.2-second guide rail switch power supply, a 2.3-first PLC200 central processing unit, a 2.4-first PLC200 thermal resistance analog input module, a 2.5-second PLC200 thermal resistance analog input module, a 2.6-third PLC200 thermal resistance analog input module, a 2.7-fourth PLC200 thermal resistance analog input module, a 2.8-fifth PLC200 thermal resistance analog input module, a 2.14-first guide rail and a 2.15-second guide rail.
FIG. 3 shows a PLC200 automatic control host A surface of the CFD thermal comfort analysis method based on a PLC200 temperature acquisition system, which comprises a 2.9-first automatic control host multifunctional power meter, a 2.10-second automatic control host multifunctional power meter and a 2.11-first industrial touch screen.
FIG. 4 shows a PLC200 automatic control host B surface of the CFD thermal comfort analysis method based on a PLC200 temperature acquisition system, comprising a 2.12-first fan and a 2.13-second fan.
Fig. 5 is a signal transmission networking of the CFD thermal comfort analysis method based on the PLC200 temperature acquisition system of the present invention, including a 3.1-first industrial ethernet communication module, a 3.2-first 8-pin RJ45 cable, a 3.3-first I/O expansion cable, and a 3.4-first small portable gateway.
Fig. 6 is a schematic diagram of the position of a temperature measurement point of the CFD thermal comfort analysis method based on the PLC200 temperature acquisition system according to the present invention.
Fig. 7 is a plot of experimental PMV versus simulated PMV for a CFD thermal comfort analysis method based on a PLC200 temperature acquisition system.
Fig. 8 is a graph showing PMV and PPD values at different temperatures and relative humidity conditions for a CFD thermal comfort analysis method based on a PLC200 temperature acquisition system.
FIG. 9 is a plot of equivalent temperature calculations for a CFD thermal comfort analysis method based on a PLC200 temperature acquisition system.
Detailed Description
Embodiments of the present invention will be described in detail below by way of specific examples with reference to the accompanying drawings.
In the implementation mode, a certain SUV plug-in hybrid flagship plate of the masses of the upper vehicles is selected, and the size of the vehicle body is 4.733 multiplied by 1.859 multiplied by 1.674m. The four blowing surface air outlets are respectively a left air outlet, a central right air outlet and a right air outlet. The total of two air outlets of the foot blowing outlets are respectively the air outlets of the foot of the driving side and the air outlets of the foot of the assistant driving side. The inner circulation air return port is positioned at the foot of the copilot. The shape is a trapezoid, which can be equivalent to a 15 x 6cm rectangle as measured. The temperature of the air outlet is set to 26 ℃, and the air outlet velocity is 2.5m/s. And collecting the temperatures of a single driver and the interior of the vehicle cabin, and arranging 20 measuring points as shown in the figure. FIG. 1 is a temperature detection network of the CFD thermal comfort analysis method based on a PLC200 temperature acquisition system, which is positioned on the C surface of an automatic control host computer of the PLC200 and comprises 1.1-first four-hole aviation male plug, 1.2-second four-hole aviation male plug, 1.3-third four-hole aviation male plug, 1.4-fourth four-hole aviation male plug, 1.5-fifth four-hole aviation male plug, 1.6-sixth four-hole aviation male plug, 1.7-seventh four-hole aviation male plug, 1.8-eighth four-hole aviation male plug, 1.9-ninth four-hole aviation male plug, 1.10-fourteenth four-hole aviation male plug, 1.11-eleventh four-hole aviation male plug and 1.12-twelfth four-hole aviation male plug which are respectively positioned on the upper part of the C surface of the automatic control host computer of the PLC 200. The 1.13-thirteenth four-hole aviation male plug, the 1.14-fourteenth four-hole aviation male plug, the 1.15-fifteenth four-hole aviation male plug, the 1.16-sixteenth four-hole aviation male plug, the 1.17-seventeenth four-hole aviation male plug, the 1.18-eighteenth four-hole aviation male plug, the 1.19-nineteenth four-hole aviation male plug and the 1.20-twenty-fourth hole aviation male plug are respectively positioned at the lower part of the C face of the PLC200 automatic control host, and 4 five-hole aviation male plug interfaces are reserved, so that the expansion is facilitated. The total 24 aviation plugs are distributed in two rows in a crossing way, the circle centers of the horizontal plugs are 3cm away, and the circle centers of the vertical plugs are 3cm away, and the angle is 60 degrees.
As shown in FIG. 2, the PLC200 automatic control host machine of the CFD thermal comfort analysis method based on the PLC200 temperature acquisition system comprises a 2.1-first air circuit breaker, a 2.2-second guide rail switch power supply, a 2.3-first PLC200 central processing unit, wherein the arrangement position of the 2.14-first guide rail of the automatic control host machine is the left side of the 2.4-first PLC200 thermal resistance analog quantity input module, a 2.5-second PLC200 thermal resistance analog quantity input module, a 2.6-third PLC200 thermal resistance analog quantity input module, a 2.7-fourth PLC200 thermal resistance analog quantity input module and a 2.8-fifth PLC200 thermal resistance analog quantity input module, and the arrangement position of the automatic control host machine is the 2.15-second guide rail. The length of the guide rail is 38cm, the width of the guide rail is 3.5cm, the distance between the 2.14-first guide rail and the 2.15-second guide rail is 15cm, the distance between the modules is more than 0.5cm, heat accumulation is avoided, and an air duct is reserved.
As shown in FIG. 3, the PLC200 of the CFD thermal comfort analysis method based on the PLC200 temperature acquisition system automatically controls the A surface of a host, and comprises a 2.9-first automatic control host multifunctional power meter, a 2.10-second automatic control host multifunctional power meter and a 2.11-first industrial touch screen. The power meter sizes are 10X 5cm, and the distance is 10cm. The first industrial touch screen has a size of 20 x 15cm and is 10cm from the power meter.
FIG. 4 shows a PLC200 automatic control host B surface based on a CFD thermal comfort analysis method of a PLC200 temperature acquisition system, which comprises a 2.12-first fan and a 2.13-second fan, and adopts a hole digging design to emit air inwards. The fan module is 17cm long and 6cm wide, and the radius of the outer cover is 4.5 cm.
As shown in FIG. 5, the signal transmission networking of the CFD thermal comfort analysis method based on the PLC200 temperature acquisition system comprises a 3.1-first industrial Ethernet communication module, a 3.2-first 8-pin RJ45 cable, a 3.3-first I/O expansion cable and a 3.4-first small portable gateway.
As shown in fig. 6, the sensor measuring point positions of the CFD thermal comfort analysis method based on the PLC200 temperature acquisition system can be acquired according to the human body temperature and the cabin temperature, and the specific measuring point positions can be arranged according to different application conditions.
The specific operation flow of the CFD thermal comfort analysis method based on the PLC200 temperature acquisition system is as follows:
1) Drawing a three-dimensional model of a passenger cabin of the new energy automobile by adopting CATIA three-dimensional modeling software, and outputting the three-dimensional model as a cabin.
2) And importing HYPERMESH the bin.stp file, dividing, selecting and renaming the surface related to the boundary condition, and dividing an air outlet and an air return opening for the entity. Partitioning Door, cabin, windows, seats, inlet, outlet; the dummy model is introduced HYPERMESH to divide the human body segment part and divide Head, body, arm, leg, hands, feet. Assembling the dummy model, and reasonably placing the dummy model on a seat by adjusting the posture and the size of the person;
3) Carrying out surface Mesh drawing on the model by using HYPERMESH self-contained Mesh function, and deriving a model. Bdf file;
4) The model. Bdf file is imported into Star-CCM+ to enter a numerical simulation calculation interface, and new parts are selected from the import mode combination box in the import surface option dialog box to be created. Clicking on the determination accepts the default import surface option. Right click geometry > parts > Model, then select to assign parts to regions. In assigning parts to region dialog boxes, a region is selected to be created for each part, and a boundary is selected to be created for each part surface. Right-click geometry > operation node, then select new > auto-grid. The following mesh generators are selected in order: cone volumetric mesh generator-polyhedral mesh generator, optional boundary layer mesh generator-prismatic layer mesh generator. Edit geometry > operation > automatic grid > default control node, set base dimension-5 mm, prism layer total thickness-relative base value 10. Right click geometry > operating node, and select execute all. For physical continuum > physical 1, the following models were selected in order: three-dimensional, steady, gas, split flow, gradient, multicomponent, turbulence, reynolds average nano-stokes, K-Epsilon turbulence, exact wall distance, achievable K-psilon two-layer model, two-layer all y+ wall treatments, split fluid temperature, thermal comfort model. Expansion area > fluid > boundary nodes, the multiple choice method selects all boundaries from 1-head to 14-right foot, setting the physical condition-thermal specification to temperature. And the same method is used to set the cab boundary thermal specification to convection. Using the multiple choice method, all boundary nodes from INLETDASHCENTRE to INLETFEETRIGHT were compiled as mass flow inlets and turbulence was set to specify the intensity + length ratio. The outlet node is set as the pressure outlet. Thermal comfort is activated, specifying the primary physical characteristics of the occupant of the vehicle. The TIM program calculates the body mass distribution and surface area value of the vascular system using the height of the passenger, sets the height to 1.8m, and defines the thermal conductivity for the clothing resistance to 0.02 Km2/W. The metabolic rate is set, a custom radio button is selected, the self-setting value is 1.24, and the setting corresponds to inputting a scale factor with 58W/m 2 as a base. The boundary corresponding to the body part of each passenger is designated, and the boundary corresponding to the body part and the initial temperature are set. Specifying a reference heat transfer coefficient for each convection boundary: windows-7.9W/m 2K, door-44.5W/m 2K, capin-44.5W/m 2K, roof-44.5W/m 2K, console-22.3W/m 2K. The inlet boundary setting part sets the inlet mass flow rate and the temperature of the fluid condition, selects an air inlet, sets the temperature to 26 ℃, and inputs the value of the mass flow rate to 0.001;
5) Creating a scalar field, editing a scene > scalar scene 1 > display > scalar 1 > component nodes, expanding an area > bin node in an editing dialog, and selecting a body boundary. Scalar 1 > scalar field node is selected, the function is set to temperature, and the unit is set to deg.c. Right-hand bond derivative-new derivative-cross section, derivative-points are created in the same way. Outputting parameters of observation points/surfaces through Calculators, and outputting the dry bulb temperature of the passenger cabin, the average radiation temperature of the passenger cabin, the temperatures of different sections of a human body, the relative humidity of a flow field and the flow velocity of the observation surfaces in the flow field;
6) Editing a field function, calculating average voting Prediction (PMV), prediction dissatisfaction percentage (PPD) and equivalent temperature (EQT) by using data obtained by reporting, and analyzing the temperature rising effect of an automobile air conditioner in a passenger cabin, the distribution of a hot-wet flow field in the cabin, the uniformity of the hot flow field and the human body thermal comfort degree, which are 4 differences. The calculation formula of the average voting Prediction (PMV) is
Wherein the metabolic rate of the M-body surface; w is the mechanical work done by human body; convection and radiation heat loss on the surface of the H-body; e e -heat dissipation and perspiration heat dissipation on the skin; amount of sensible heat loss in C res -breath; e res -amount of latent heat lost in breathing. The calculation formula of the dissatisfaction percentage is as follows:
Wherein i represents a segment of a human body, T eq,i represents an equivalent temperature of the i segment, T s,i represents a surface temperature of the i segment, v air,i represents an air flow rate around the i segment, S i represents a total surface area of the i segment, T a,i represents an air temperature around the i segment, sigma represents a Stefan-Boltzmann constant, 5.67×10 -8W/(㎡·K4),εi represents an emissivity of the i segment, f i,n represents an angular coefficient of the i segment to a surface of a component, T i represents a convective heat transfer coefficient of the i segment calibrated by a susceptor in a standard environment, Q sol represents solar radiation received by the human body, h cal,i represents a convective heat transfer coefficient of the i segment, and 8.7W/(. Square.K).
According to numerical simulation, after the temperature rising time of 30min passes, the temperature in the air conditioner is increased along with the time change, the position with higher air temperature is located in the area directly blown by jet flow of the air outlet of the air conditioner, and the air flow is hindered by the automobile roof and flows to the rear-row area along the roof to heat the automobile roof. Generally, the front region of the vehicle is at a higher temperature than the rear region, and the upper air temperature of the vehicle is at a higher temperature than the lower air temperature of the vehicle in the vertical direction, resulting in a significant difference in temperature between the front and rear head and foot positions. The vicinity of the dashboard, front window glass, etc. belongs to a low temperature region.
In the TCM module, it is assumed that the mannequin assumes that the head and hands are not attached with clothes, so that the calculated surface temperatures of the head and hands of the occupant are skin temperatures thereof, and the rest are clothes surface temperatures of corresponding positions. During the heating process, the surface temperature of clothes of front and rear passengers rises to different degrees. The rising trend of the surface temperatures of the trunk, the big arm and the thigh is consistent, but the surface temperatures of the trunk and the big arm are always slightly higher than the surface temperature of the thigh, because the upper air temperature in the cabin is always higher than the lower air temperature, and the air temperature at the foot position is low, so that the surface temperature of the foot is relatively always lower due to the low air flow rate.
On the premise that other air supply constants are kept unchanged, the airflow organization forms at all air supply temperatures are almost identical, but the average air temperature in the vehicle is obviously changed, and the thermal comfort of passengers is affected to a certain extent. The local thermal comfort of the exposed parts such as the head, the face, the hands and the like is reduced with the increase of the air supply temperature along with the increase of the thermal sensation. The thermal comfort performance of the garment covered portion is different from one portion to another, although the thermal sensation is improved.
As shown in FIG. 7, under the condition that the ambient temperature is 15 ℃, the air supply temperature is 26 ℃, under the working condition that the air supply speed of 2.5m/s is ensured, the calculated PMV of human body accords with the ISO 7730 national standard after 8min, reaches the interval of [ -0.5,0.5], the human body is in a thermal comfort state, the PPD is less than 10%, and the maximum error of experiments and simulation accords with the engineering error range.
As shown in fig. 8, when the temperature in the vehicle interior is 26 c and the relative humidity is reduced from 70% to 30%, the dissatisfaction ratio PPD of the environment inside the passenger compartment is reduced by 4.73%, and the value of PPD is 16.919%. When the temperature in the cabin is 30c and the relative humidity is reduced from 70% to 30%, the dissatisfaction rate PPD of the thermal environment in the passenger compartment is reduced by 82.3%. When the temperature is a fixed value, the heat sensation of a human body can be improved by improving the relative humidity of the indoor environment, the human body can feel warmer, and the cold sensation of the human body can be enhanced by reducing the relative humidity of the indoor environment.
As shown in fig. 9, the temperature calculated value is located between the upper and lower equivalent temperature limits, which proves that the calculated result is in the comfort range of human body and meets the comfort requirement of 'head cold and foot warm'.
The above embodiments are merely illustrative of the design principles and the application of the present invention and are not intended to limit the present invention. Modifications and variations may be made to the above-described embodiments by those skilled in the art without departing from the spirit and scope of the invention. Accordingly, it is intended that all equivalent modifications and variations of the invention be covered by the claims, which are within the ordinary skill of the art, be within the spirit and scope of the present disclosure.
Claims (9)
1. CFD thermal comfort analysis method based on PLC200 temperature acquisition system, its characterized in that:
The CFD thermal comfort analysis method based on the PLC200 temperature acquisition system comprises a temperature detection network, a PLC200 automatic control host, a signal transmission networking and a new energy automobile cabin air conditioning system;
The temperature detection network comprises a first four-hole aviation male plug (1.1), a second four-hole aviation male plug (1.2), a third four-hole aviation male plug (1.3), a fourth four-hole aviation male plug (1.4), a fifth four-hole aviation male plug (1.5), a sixth four-hole aviation male plug (1.6), a seventh four-hole aviation male plug (1.7), an eighth four-hole aviation male plug (1.8), a ninth four-hole aviation male plug (1.9), a fourteenth hole aviation male plug (1.10), an eleventh four-hole aviation male plug (1.11), a twelfth four-hole aviation male plug (1.12), a thirteenth four-hole aviation male plug (1.13), a fourteenth four-hole aviation male plug (1.14), a fifteenth four-hole aviation male plug (1.15), a sixteenth four-hole aviation male plug (1.16), a seventeenth four-hole aviation male plug (1.17), an eighteenth four-hole aviation male plug (1.18), a nineteenth four-hole aviation male plug (1.19) and a twenty-fourth aviation male plug (1.20);
The PLC200 automatic control host comprises a first air circuit breaker (2.1), a first guide rail switching power supply (2.2), a first PLC200 central processing unit (2.3), a first PLC200 thermal resistance analog input module (2.4), a second PLC200 thermal resistance analog input module (2.5), a third PLC200 thermal resistance analog input module (2.6), a fourth PLC200 thermal resistance analog input module (2.7) and a fifth PLC200 thermal resistance analog input module (2.8); the first automatic control host computer multi-signal power meter (2.9), the second automatic control host computer multi-signal power meter (2.10), the first industrial touch screen (2.11), the first fan (2.12), the second fan (2.13), the first guide rail (2.14) and the second guide rail (2.15);
The signal transmission networking comprises a first industrial Ethernet communication module (3.1), a first 8-pin RJ45 cable (3.2), a first I/O expansion cable (3.3) and a first small portable gateway (3.4);
The first four-hole aviation male plug (1.1), the second four-hole aviation male plug (1.2), the third four-hole aviation male plug (1.3), the fourth four-hole aviation male plug (1.4), the fifth four-hole aviation male plug (1.5), the sixth four-hole aviation male plug (1.6), the seventh four-hole aviation male plug (1.7), the eighth four-hole aviation male plug (1.8), the ninth four-hole aviation male plug (1.9), the fourteenth hole aviation male plug (1.10), the eleventh four-hole aviation male plug (1.11) and the twelfth four-hole aviation male plug (1.12) are respectively positioned on the upper part of the C surface of the PLC200 automatic control host. The thirteenth four-hole aviation male plug (1.13), the fourteenth four-hole aviation male plug (1.14), the fifteenth four-hole aviation male plug (1.15), the sixteenth four-hole aviation male plug (1.16), the seventeenth four-hole aviation male plug (1.17), the eighteenth four-hole aviation male plug (1.18), the nineteenth four-hole aviation male plug (1.19) and the twenty fourth hole aviation male plug (1.20) are respectively positioned at the lower part of the C surface of the PLC200 automatic control host computer, and 4 five-hole aviation male plug interfaces are reserved, so that the expansion is facilitated. The total 24 aviation male plugs are distributed in two rows in a crossing way, the circle centers of the horizontal plugs are 3cm away, the circle centers of the vertical plugs are 3cm away, and the angle is 60 degrees;
The arrangement positions of the first air circuit breaker (2.1), the first guide rail switching power supply (2.2) and the first PLC200 central processing unit (2.3) are the left side of a first guide rail (2.14) of the self-control host. The arrangement positions of the first PLC200 thermal resistance analog input module (2.4), the second PLC200 thermal resistance analog input module (2.5), the third PLC200 thermal resistance analog input module (2.6), the fourth PLC200 thermal resistance analog input module (2.7) and the fifth PLC200 thermal resistance analog input module (2.8) are self-control host computer second guide rails (2.15); the length of the guide rail is 38cm, the width of the guide rail is 3.5cm, the distance between the first guide rail (2.14) and the second guide rail (2.15) is 15cm, the distance between the modules is ensured to be more than 0.5cm, heat accumulation is avoided, and an air duct is reserved;
the first automatic control host machine multi-signal power meter (2.9), the second automatic control host machine multi-signal power meter (2.10) and the first industrial touch screen (2.11) are arranged on the A surface of the automatic control host machine, the two multi-functional power meters are evenly distributed at the upper part, and the industrial touch screen is arranged at the lower part;
The first fan (2.12) and the second fan (2.13) adopt a hole digging design, are positioned on the B surface of the automatic control host machine, are used for exhausting air inwards, and adopt a circular grid to avoid damage caused by large particles entering the box body;
The CFD thermal comfort analysis method based on the PLC200 temperature acquisition system is as follows:
1) Drawing a three-dimensional model of a passenger cabin of the new energy automobile by adopting CATIA three-dimensional modeling software, and outputting the three-dimensional model as a cabin.
2) And importing HYPERMESH the bin.stp file, dividing, selecting and renaming the surface related to the boundary condition, and dividing an air outlet and an air return opening for the entity. Partitioning Door, cabin, windows, seats, inlet, outlet; the dummy model is introduced HYPERMESH to divide the human body segment part and divide Head, body, arm, leg, hands, feet. Assembling the dummy model, and reasonably placing the dummy model on a seat by adjusting the posture and the size of the person;
3) Carrying out surface Mesh drawing on the model by using HYPERMESH self-contained Mesh function, and deriving a model. Bdf file;
4) Importing the model. Bdf file into Star-CCM+ to enter a numerical simulation calculation interface, adjusting equations, materials, boundary conditions, algorithms and file storage forms according to calculation requirements of the model, and calculating after the adjustment is completed;
5) Setting a calculation report, selecting and setting an observation point and an observation surface, and outputting a dry bulb temperature of the passenger cabin, an average radiation temperature of the passenger cabin, temperatures of different segments of a human body, relative humidity of a flow field and flow velocity of the observation surface in the flow field;
6) Editing a field function, calculating average voting Prediction (PMV), prediction dissatisfaction percentage (PPD) and equivalent temperature (EQT) by using data obtained by reporting, and analyzing the temperature rising effect of an automobile air conditioner in a passenger cabin, the distribution of a hot-wet flow field in the cabin, the uniformity of the hot flow field and the human body thermal comfort degree, which are 4 differences.
2. The CFD thermal comfort analysis method based on the PLC200 temperature acquisition system according to claim 1, wherein:
the numerical simulation software selected by the method is Star-CCM+.
3. The CFD thermal comfort analysis method based on the PLC200 temperature acquisition system according to claim 1, wherein:
The software for drawing the three-dimensional model is CATIA and AutoCAD drawing software.
4. The CFD thermal comfort analysis method based on the PLC200 temperature acquisition system according to claim 1, wherein:
when a doll model is arranged in a numerical simulation calculation interface, fiala human body models are required to be layered.
5. The CFD thermal comfort analysis method based on the PLC200 temperature acquisition system according to claim 1, wherein:
and calling a TCM module in Star-CCM+ when the model of numerical simulation is selected.
6. The CFD thermal comfort analysis method based on the PLC200 temperature acquisition system according to claim 1, wherein:
and a temperature detection network is arranged in the physical vehicle cabin, and the change trend of the flow field is recorded and analyzed.
7. The CFD thermal comfort analysis method based on the PLC200 temperature acquisition system according to claim 1, wherein:
And comparing the actual vehicle cabin with the three-dimensional model, and verifying the reliability of the output data.
8. The CFD thermal comfort analysis method based on the PLC200 temperature acquisition system according to claim 1, wherein:
Calling Star-CCM+animation production module to clearly observe the variation trend of the intra-cabin hot-wet flow field.
9. The CFD thermal comfort analysis method based on the PLC200 temperature acquisition system according to claim 1, wherein:
The four-hole aviation male plug can be matched with thermal resistance sensors of different types and different resistance values to be used, and meets the occasion requirements of different precision.
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