Present Situation of Application of Hot Temperature Heating Body Digpent in Comfort Evaluation

Considering that the special dress environment will cause cold and hot stress, the special functional clothing is necessary to make comfort evaluation before investing in use, and it is determined that the body's body is engaged in a designated environment, whether the human physiological indicators can maintain normal. The relevant evaluation method is mainly in human experiment 1-2, but for complex environments such as extremely cold, heat or fire, it is inconvenient to use live experiments, and the human subject's subjective factor will generate uncontrollable errors, so there is a combustion dummy. Alternative devices such as warm body dummy, have the advantages of high experimental results, high repeatability.

Thermal dummy has been adopted as an important means of clothing heat, wet resistance test, and acquisition of standard agencies such as international standardization organization (ISO), US Materials and Test Association (ASTM). Dry, wet heat loss of clothing, and evaluate clothing comfort. However, such test methods can only objectively watch the insulation wet resistance of the conquest, and cannot reflect human comfort. Later, Holmer proposed the thermal resistance (IREQ) model required for clothing, which specifies that the heat insulation capacity to avoid cold stress and clothing 3, which can determine whether it is compared to the actual thermal resistance, can judge whether it can be determined Safeguarding human comfort 4-5, this indicator is adopted by ISO 11079: 2007 "hot environmental effect" mdash; mdash; The thermal resistance or the required thermal resistance, such warm body dummy experiments are from the angle of clothing, and the specific human body is not available. Later, some scholars bind to the temperature and humidity sensor, and evaluate human comfort 6-7 by analyzing the temperature and humidity of the microenvironment under the clothes. Although, microcarrier parameters can indirectly reflect the human body, but it is still impossible to understand the impact of conquering the thermophysis of human body. Subsequently, the construction and improvement of body temperature regulation models based on the 25 node model of Stolwijk et al. 8 provides new ideas for clothing comfort. Tanabe et al. 9 proposes to combine the body temperature adjustment model with the numerical dummy, by calculating the fluid mechanics software, the temperature distribution of the fake human body table and the surrounding environment, but did not consider the factors of clothing at the time. Later, the US Renewable Energy Institute initially proposed the thermal adjustment model concept of the warm body dummy, coupling the body temperature regulation mechanism and the dummy system 10, integrated environment, clothing and human factors, so that the warm body dummy can simulate the human body Thermally reacts, obtains transient tipping, hypothalamus temperature, providing more practical physical significance parameters for clothing comfort, expanding the scope of comfort.

This paper focuses on the application of thermal adjustment operation mode in the evaluation of clothing comfort, with three operating modes common to the warm body dummy, analyzed its advantages and disadvantages It is pointed out the feasibility and necessity of developing thermal adjustment mode, and describes the development and application status. Finally, it is compared with the full-scale thermal adjustment of the value, summarizes the hot adjustment.Dummy future direction of development.

1 Warm-body dummy common mode of operation

When the warm body dummy evaluates clothing comfort, it is usually used in the use of clothing heat, wet resistance. two indicators. The test of hot resistance has three modes of constant skin temperature (CT), constant heat flow (CHF) and thermal comfort (TC). It can be seen from the definition of three test modes from ASTM and ISO standards. The three mode operation principles are different, and the fake human skin temperature and heat power setting are different, so the applicable thermal environment is also different. The constant skin temperature mode sets the fake people in each segment of the skin of 34 ~ 35 ° C, and the fake person protects the temperature of the skin temperature by self-regulating the power of the heating system. However, due to 34 ~ 35 ° C for the skin temperature in the human thermal neutral environment, the constant skin temperature mode is suitable for non-extreme environments. The constant heat flow mode is applied to various environments according to the human motion load, so it is suitable for various environments, but since the prostitute lacks the thermal adjustment function, the fake people's skin temperature will continue to rise as the heating power increases, deviates from the actual situation of the human body therefore controllability is not strong 11. Hot comfort mode is a control model in the human body hot comfort equation proposed in Fanger, there is a process similar to human thermal adjustment, but it is only suitable for thermal neutral conditions 12. Constant current mode is the usual skin temperature resistance test mode is recommended ASTM standard test mode used. correspond to three modes of three different algorithms, and thus different test results. Table 1 shows the difference between the constant heat flow mode test value and the thermal comfort mode test value when testing the thermal resistance of the clothing using different methods. From the table, constant heat flux mode test results were significantly higher than thermal comfort mode, the difference was up to 78.4%. In addition, clothing resistance test is ISO 9920: 2009 "Hot Environment Effective Effect Mdash; Mdash; Apparel Hot Wet Mapping", ISO 7730: 2005 "Hot Environment Effective Effect Mdash; mdash; PMV, PPD, Local Hot Comfort Indicators Calculate hot comfort, ashare 55 mdash; 2013 "Human living hot environmental conditions", ASTM F1291 MDash; 2016 "Standard Test Method for Test Garment with Heaters Dummy Test Garment", different standards have different standards, such as The ISO 9920 constant skin temperature mode specifies that the skin temperature is 32 ~ 34 ° C, and the ASTM F1291 specifies the skin temperature of 35 ° C. For the same clothing, the thermal resistance reference value given by ISO 7730 is greater than ashare 55 16, which makes standardization loses significance, so it is necessary to seek a closer to the human body's true state of the human body to evaluate clothing comfort.

In summary, the three-class evaluation costumes commonly used in warm body fake people have a significant deficiency: 1) only applicable to a biasing neutral environment. Environmental factors that affect body systems hot dressPassing 17, commonly used 3-class modes cannot characterize special protective clothing in their dressing environment and human actual fitting comfort; 2) The difference between test standards and mode is obvious. The standard is recognized by the three modes, which increases the space of the test staff, and also adds an error of evaluating clothing comfort; 3) Ignore the complex human internal thermal adjustment mechanism. About human body mdash; clothing mdash; environmental system heat transfer, only considering skin mdash; clothing mdash; environmental heat exchange. On the one hand, the skin temperature of the dummy is not actually physically, and the heating power does not have actual physical meaning. On the other hand, it is impossible to reflect a particular environment, and the clothing affects the process of thermal regulation of human body, or the effect of environmental transient changes to the human body.

2 Heat regulation mode

In view of the common three types of operation modes, the human body thermal adjustment reaction is unmovable, and the scholars have tried different ways to make The warm body dummy is closer to the real body. For example, the results of the human body experiment are set for different temperatures 18 for different sections of the fake people. Flexibility, but did not essentially make up for the defects that cannot simulate thermal regulation. The fake person needs to automatically adjust the heating power according to the environment and dressing, so that the skin temperature is adjusted toward the hot and comfortable direction 10, similar to the design concept of smart products 20. With the development of numerical simulation research in the field of apparel, the human body temperature adjustment mathematical model has matured, in which the 25-node model 8 of Stolwijk is most classic, and Fiala et al. 21-22, Tanabe et al. 9 in Stolwijk On the basis, improve blood circulation systems, provides a foundation for the development of thermal adjustment models. The development and application of thermal regulation modes depend on the coupling of the body temperature adjustment model and the dummy.

2.1 Multi-node body temperature adjustment model The human body temperature adjustment mechanism is shown in Figure 1, including control system (active system) and control system (passive system), Among them, the control system is responsible for making a corresponding adjustment reaction in accordance with real-time body temperature to ensure constant internal temperature, including response to low temperature regulation, muscle trembling and blood vessel contraction, adjustment of high temperature adjustment, skin sweating and blood vessels. The passive system is responsible for responding to the body temperature adjustment, including the composition of the human body and the heat exchange system in the human body and the human body and the outside environment 21-22.

The body temperature adjustment model describes the causal relationship in the body temperature adjustment mechanism in the form of a mathematical equation, and by solving the result of solving the body temperature adjustment by solving the equation. Initially, the body temperature adjustment model was used in the fields of HVAC, aerospace, etc., and later gradually expanded to the field of clothing. Existing classic models are summarized in Table 2, where Fiala model and multi-node Pierce modelFor the empirical model, the rest is the theoretical model. The theoretical model has a wider range of applications, and the experience model is higher than the accuracy of the applicable range 23.

This paper introduces the characteristics of the passive system and the active system to the Pumenity Coupled Fiala model.

2.1.1 Passive adjustment system

FiAla model is based on medium male human body, dividing the human body into 15 sections, each section according to each structure The characteristics are divided into multi-layer structures, including 7 different tissue materials: brain, lungs, bones, muscles, internal organs, fat, skin 22. The three square sections were separated from each segment, and the models were guaranteed to have a non-uniform environment.

Transient heat transfer of each node in the human body, based on the Pennes biological heat equalization (1). The left side of this equation considers the radial thermal conduction between the nodes, the metabolic heat of each node, each node through the convection heat transfer of the blood flow, the right side of the equation is the node transient heat storage. Simplified transverse heat transfer between nodes, only considering the heat transfer caused by radial temperature difference. Although in theory, the lateral heat transfer is compared, the lateral heat transfer is small, negligible, but if the thermal adjustment model is applied to the warm body dummy system, the model and actual The situation does not match, reduce the control accuracy of the model.

: k is the thermal conductivity; T is the node temperature; R is a node half-path; omega; is geometric; rho; B is blood density; WBL is blood diffusion rate; CBL For blood heat capacity; TBL, A is the arterial blood temperature; rho; is a node density; C is a node heat capacity; T is time.

2.1.2 Active adjustment system

The human body temperature adjustment system judges the thermal feeling of human transients under the temperature of each node of the human body under hot neutral conditions. The corresponding body temperature adjustment reaction is then made so that the temperature of each node tends to set the value.

Fiala is regressive analysis of 26 sets of independent experiments, quantizing the human body actively regulating the heat regulating effect, as shown in the formula (2) ~ (5) 21, The drive of the thermal regulation reaction is mainly the difference between the skin and the hypothalamus temperature and the set temperature.

In the formula (2) ~ (5): SH is the heat generated by the muscle trembling; ΔTsk, m is the difference between the actual average skin temperature and set value; △ THY is actual The difference between the hypothalamus temperature and the set value; TSK, M is the average skin temperature; T is time; CS is the heat flow of vascular contraction; SW is the heat generated by skin sweating; DL is the heat flow of blood vessels.

2.2 Body temperature adjustment model and heaten dummy system coupling

Use the body temperature adjustment model described in 2.1 to control the operation of the heater dummy system, the thermal adjustment inside the dummy and The heat transfer is carried out by numerical simulation, skin mdash; costume mdash; thermal exchange of the environment actually exists. The specific runtime process is shown in Figure 2.

The prostitute provides the thermal state of the body as the input parameter of the body temperature adjustment model, that is, the error value in Fig. 2, the model calculates the result of the body temperature adjustment in this state, and then feeds back the calculation result feedback to the dummy 30, the fake person adjusts heating power, the system is constantly iterative, until the fake person reaches a stable state. Such a body temperature adjustment model is initially proposed by NREL, which is used to evaluate the aerospace liquid cooling suit, and the temperature change of the fake people's body surface is obtained by observing the temperature change of the fake people's body surface. It is judged that the body is hot and comfortable. Later, the Swiss EMPA Institute 30, Northwest Testing Technology Corporation (MTNW) 31-32, Alto University 33 is engaged in the development of thermal conditioning warm body dummy, used to evaluate fire protection service, smart clothing, etc. Thermal adjustment of the human body.

3 The application of thermal modulation of the throttle

From the perspective of objective evaluation, the warmers are controlled by the thermal adjustment model. Under From the perspective of subjective evaluation, combined with subjective thermal sensation experience models, subjective thermal sensation and comfort evaluation values under human transients and steady states can be obtained. This is the main application of hot adjustment dummy in clothing comfort.

3.1 Steady-state heat sensation prediction

Document 33 Use multiple node Pierce body temperature adjustment model to control the warm body dummy, predict different ambient temperature, humidity, and wind speed conditions The temperature value of all sections of the fake man and the use of the University of California Berkeley to predict the local thermal feeling of the human body, while comparing the subjective thermal sensory voting value based on Ashare 9 subjective evaluation ruler. The results showed that the UCB hot comfort model predictive results were basically consistent with subjective evaluation results. Among them, for the prediction results of the lower body closer to subjective evaluation, the reason is mainly the accuracy of the UCB thermal comfort model predictive value, the heat regulation model pair local skin temperature and metabolism Effect of predictive accuracy of heat generation. Considering the subject from the study from the tropics, and the multi-node Pirece body temperature adjustment model constructs the human body from non-tropical regions, which may be one of the causes of the prediction results and subjective evaluation results. It can be seen that there is a difference in the adjustment mechanism of different people.Havenith et al 34 also pointed out that when building human sweating, it is pointed out, so when using the hot adjustment dummy to evaluate the comfort of clothing, the corresponding body temperature adjustment model should be coupled according to the attachment of the film. Most of the current classic models are constructed by Scholars in Europe and America, and the Asian-African region should build their own model. FODA et al 33 simultaneously uses an equivalent temperature model to predict local thermal feeling, and compare the predictive results with the hot sensory voting value based on BEDFORD 7 subjective evaluation ruler, and the result is similar to the UCB model.

FODA et al. 11 In 2012, the multi-node Pierce model was used for thermal sensation evaluation experiments. At the same time, the controlled experiment was carried out using a constant skin temperature mode and a subject, and the equivalent temperature model was used to evaluate the subjective heat. feel. The comparison result shows that the time is shorter than the constant skin temperature mode, the thermal adjustment mode reaches a stable state, and the thermal sensation evaluation results are closer to the subject evaluation results, but the two still have some slight gap. It can be seen that the fake person's thermal adjustment model will never replace the live experiment. Redortier et al 35 and Burke et al. 36 When using the thermal adjusted dummy, the hot adjustment mode prediction is similar to that of the live-action experiment, but is more obvious in local differences. WANG 37 has also been analyzed in his research report whether to replace the true human body in his research report. Better match the thermal adjustment model.

3.2 Transient thermal sensory prediction

For the human body in any heat environment, especially special environments, in most cases, the human body is inadvertent, so The prediction of transient thermal feelings is more practical. After the development and standardization of thermal sensory models such as Equivalent temperature, PMV, complex transient thermal feelings become the focus of scholars, including representatives of ZHANG and other research results 38-40, summarized the non-uniform environment The UCB experience model of the human body and overall transient thermal sensation and thermal comfort. Literature 31 uses ADAM dumpers, coupled NREL autonomous development of finite element body temperature regulating model, evaluating the impact of protective clothing on the physiological parameters of human body, and applied to the UCB experience model.

Farrington et al 32 uses the ADAM dummy and NREL body temperature adjustment model, evaluating the cooling effect of the spaceless liquid cooling service to the human body, and use an infrared camera to shoot an infrared image of the fake man's surface, get the clothing The temperature distribution of the surface is to evaluate the local cooling effect of the clothing. It can be seen that the use of the thermal adjustment mode of the warm body prostitute can simulate the true thermal reaction process of the human body, on the other hand, the temperature information of the outer surface of the garment, external sensor can be combined, providing more comfort. Many information, expand the scope of comfort.

7 combined with the Fiala thermal adjustment model and Newton warm body dummy, predict the changes in the temperature and core body temperature in different fabrics to configure the temperature and core body temperature, and then use the UCB thermal comfort model to predict the thermal feeling of the human body in the process. It is to analyze the effects of the sportswear fabric configuration on the hot humidity of human body, as shown in Figure 3. The results of the experiment reflect the advantages of multi-zone block temperature regulation model.

In the field of military uniforms, considering that military people often engage in the tasks such as load-bearing military, the human body will suffer from thermal stress, and evaluate the military uniforms, which is to ensure the safety of military personnel and improve job efficiency. Important means. Miyo et al 29 using the US military research and development, the thermal adjustment model predicts the skin temperature and core temperature wearing military uniform in high temperature environment, and then uses the physiological stample indicator to determine the degree of thermal suits that the human body suffer from the operation process, providing military uniform design Guided opinion.

The thermal conditioning body dummy in the field of clothing comfort evaluation, predicted the skin temperature and core temperature, and then use the subjective thermal sensation experience model to predict the model of the subjective feeling of the body, it is impressed Application of clothing evaluation such as aerospace service, sportswear. At present, the predictive results of the thermal regulation mode are closer to the real situation than the traditional model, but there is still an improved space.

4 Comparative Analysis, Test Research, Numerical Simulation and Three Methods of Scientific Research, Numerical Simulation Among them, the numerical simulation has become a major development direction in the field of clothing protection and comfort in the field of clothing protection and comfort in the field of clothing protection and comfort in the field of clothing protection and comfort.

The hot-conditioned throttle dummy evaluation costume comfort is the combination of experimental research and numerical simulation, and there is also the authenticity of the former and the flexibility of the latter. However, the numerical simulation of full scale has become a research trend in recent years. Among them, the research of fabric levels has been quite rich, especially in the field of heat protection, through the grasp of heat flow and other boundary conditions, can predict the skin burns 42 -43. Combined with Computational Fluid Dynamics (CFD) Tests for Visual Numerical Simulation of Fabric Heat Protection Performance (TPP) test, predict the thermal protection performance of fabrics 41. At the fitting level, some scholars combine hot regulating model, skin mdash; clothing mdash; environmental system heat transfer model, construct full scale thermal adjustment numerical dummy model 44, evaluation of clothing comfort.

Theoretically analyzed the advantages and disadvantages of the thermal conditioning body dummy and the hot adjustment of the value of the fake people, as shown in Table 3, the hot adjustment value dummy can make up for the genital dummy in the model and dummy. Defects, improve the accuracy of forecast results, and more valuable information can be obtained. Tanabe et al. 9 used 65 node body temperature adjustment models with a valuable dummy to carry out the environment compartmentThe full scale simulation test of the human body has been obtained by the temperature and humidity distribution of each segment of the fake person. Burker et al. 45 also used the FiAla body temperature adjustment model to perform numerical dummy and warm body dummy test, an environment of 25 ° C, 46.52 w / m2 metabolic heat, and the results are shown in Figure 4, each segment temperature The distribution trend is consistent, but the local temperature difference is large, up to 2 ° C. However, the above studies have not been compared using the real person, so the accuracy of the two simulation results has no attention.

Currently, the value of the hot adjustment value is used to analyze the environment on the human body, considering the research of clothing factors, and the related applications of hot warmers fake people more. As two means of apparel evaluation, the two have advantages, and the accuracy of improving the prediction results is the direction in which the two methods need to be further improved.

5 Conclusion

The Human Heat Regulation Model With the coupling of the warm body dummy system to achieve the function of the dummy body, compensate Constant skin temperature, constant heat flow, heat comfort 3 mode of operation, so that the warm body dummy is not only used to perform clothing resistance evaluation, or simulate the response, transient and steady state of the human body on different thermal environments. The human body table parameters can be used for the thermal sensation model, evaluating the comfort of any moment of installing, and provides reference for the improvement of clothing. At present, the hot adjustment dummy has been applied in the field of fire service, sportswear, aerospace hollow suit, but still has some shortcomings and improved directions.

1) The thermal adjustment mode is not standardized, and the application is not a wide range. At present, the most popular FIAALA and multi-node Pierce models are experienced, and after separating the specific environment and human activity load range, the predicted accuracy is not guaranteed, and only through constant experimental verification, the thermal adjustment model is perfected, and the error is incremented Minimal; can be considered that the fake people and the thermal adjustment model have to be improved, on the one hand, the fake people are three-dimensional heat, and the numerical model only consider one-dimensional heat, on the other hand, the dummy segment and the thermal adjustment model The segment is inconsistent in segmentation and quantity, which will lead to the accuracy of model regulation. The thermal adjustment model can be used

The value of the dummy is divided into the human body torso, which demonstrates a stronger adaptability when responding to the heaters of the number of different sections.

2) R D developed with a targeted thermal conditioning of people or Asian people. In the 1980s, China has begun research work in the numerical model of body temperature, and has achieved many non-uniform cold and thermal environments, mostly used in aerospace cabin environment design and aerospace cold servic evaluation. Since the 21st century, related research results and application are rare. With numerical simulation research, it has become a major development direction in clothing comfort evaluation, whether it is applied to a warm body dummy or a numerical dummy, there is a need to continue in the futureSignificant body temperature adjustment model for Chinese human characteristics.

3) Coupling of the thermal sensory model.At present, the application of the thermally modulated heaters will eventually fall to the heat sensation or hot comfort. If the standardized subjective thermal sensation model (eg equivalent temperature, PMV) and thermal adjustment model are operated with dummySystem coupling can greatly improve trial efficiency.