Method and System for Predicting Human Metabolic Rate Based on Indoor and Outdoor Air Composition

Abstract

The present invention relates to a method and system for predicting human metabolic rate based on indoor and outdoor air composition, which obtains the fresh air volume entering the indoor space, the number of people in the indoor space, and the height and weight corresponding to each person; obtains the concentration of a set gas, air temperature, and atmospheric pressure in the indoor and outdoor environments; converts the concentration of the set gas through unit conversion, and combines it with the air temperature, atmospheric pressure, and molecular weight of the set gas to obtain the density of the set gas. Based on the indoor pollutant diffusion equation, the production rate of the set gas by the human body in the indoor space is obtained and corrected to a value under standard conditions; according to the height and weight corresponding to the person, the body surface area of each person is obtained, and using the production rate and respiratory quotient of the set gas under standard conditions, the metabolic rate is determined based on the indirect calorimetry method, and after time-phase correction, the final human metabolic rate is obtained.

Description

Technical Field

[0001] The present invention relates to the technical field of building thermal environment, and specifically to a method and system for predicting human metabolic rate based on indoor and outdoor air components. Background Technique

[0002] The statements in this part only provide background technical information related to the present invention and do not necessarily constitute prior art.

[0003] Human metabolic rate is the heat generated per unit surface area of the human body per unit time and is one of the basic parameters for the human body to maintain life activities. In the current standard "Ergonomics of the thermal environment - Determination of metabolic rate", the prediction methods for various metabolic rates are sorted out and divided into multiple levels with different degrees of accuracy.

[0004] The common measurement principles of metabolic meters on the market are all indirect calorimetry. By wearing sensors on set parts of the human body, relevant data is collected in a laboratory environment and the human metabolic rate of the measured person is predicted through calculation. This method is prone to restricting the free movement of the measured person due to the need to wear sensors, and is limited to the laboratory environment, resulting in unsatisfactory convenience in the process of metabolic rate detection and prediction. Summary of the Invention

[0005] In order to solve the technical problems existing in the above background technique, the present invention provides a method and system for predicting human metabolic rate based on indoor and outdoor air components. By collecting the changes in CO2 concentration or O2 concentration and the fresh air volume of the room indoors and outdoors, the human metabolic rate is predicted and calculated based on the indirect calorimetry method and the pollutant diffusion equation. Since people move indoors, the sensors can be arranged inside and outside the building, and there is no need to wear sensors. It has the advantages of free movement of personnel, real-time monitoring, high calculation accuracy, and strong portability, and can provide key technologies for the development of intelligent and green human settlements in the construction industry.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] The first aspect of the present invention provides a method for predicting human metabolic rate based on indoor and outdoor air components, including the following steps:

[0008] Obtain the fresh air volume entering the indoor space, the number of people in the indoor space, and the height and weight of each person;

[0009] Obtain the concentration of the set gas, air temperature, and atmospheric pressure in the indoor and outdoor environments;

[0010] The concentration of the set gas is unit-converted, and combined with the air temperature, atmospheric pressure, and the molecular weight of the set gas to obtain the density of the set gas. Based on the indoor pollutant diffusion equation and the fresh air volume, the generation rate of the set gas by the human body in the indoor space is obtained and corrected to the value under standard conditions;

[0011] According to the height and weight corresponding to the person, the body surface area of each person is obtained, and using the generation rate and respiratory quotient of the set gas under standard conditions, the metabolic rate is determined based on the indirect calorimetry method. After time-phase correction, the final human metabolic rate is obtained.

[0012] Further, the set gas includes carbon dioxide or oxygen.

[0013] Further, the unit conversion is specifically: the unit of the concentration of the set gas is ppm, and according to the atmospheric pressure and the molecular weight of the gas, it is converted to g / m 3 .

[0014] Further, the concentration of the set gas is unit-converted, and combined with the air temperature, atmospheric pressure, and the molecular weight of the set gas to obtain the density of the set gas, as shown in the following formula:

[0015]

[0016] In the formula, ρ X is the density of the indoor gas X, M X is the molecular weight of the set gas X, R is the gas constant, and T is the thermodynamic temperature.

[0017] Further, based on the indoor pollutant diffusion equation and the fresh air volume, the generation rate of the set gas by the human body in the indoor space is obtained, as shown in the following formula:

[0018]

[0019] In the formula, C i+1 and C i are the concentrations of the set gas X at the (i + 1)-th and i-th moments respectively, V is the volume of the indoor space, C o,i is the concentration of the set gas X outside the room at the i-th moment, g / m 3 , Gτ is an infinitesimal time interval, ρ X is the density of the set gas X, and G is the fresh air volume of the room.

[0020] Further, the set gas generation rate is corrected to the value under standard conditions, as shown in the following formula:

[0021]

[0022] In the formula, P H2O is the saturated water vapor partial pressure, VX is the set gas production rate under standard conditions.

[0023] Furthermore, the metabolic rate is determined based on indirect calorimetry, as shown in the following formula:

[0024]

[0025] In the formula, RQ is the respiratory quotient, M is the metabolic rate, and V X is the production rate of gas X by the human body under standard conditions.

[0026] Furthermore, time phase correction is performed, specifically: determining the delay time t0 required for the diffusion process of the set gas X, and the corrected metabolic rate is M r (τ - t0) = M(τ).

[0027] The second aspect of the present invention provides a human metabolic rate prediction system based on indoor and outdoor air components, including:

[0028] An information input module, configured to: obtain the fresh air volume entering the indoor space, the number of people in the indoor space, and the height and weight corresponding to the people;

[0029] A parameter acquisition module, configured to: obtain the concentration of the set gas, the air temperature, and the atmospheric pressure in the indoor and outdoor environments;

[0030] A numerical processing module, configured to: convert the concentration of the set gas, and together with the air temperature, the atmospheric pressure, and the molecular weight of the set gas, obtain the density of the set gas, and based on the indoor pollutant diffusion equation, obtain the production rate of the set gas by the human body in the indoor space, and correct and process it to a value under standard conditions;

[0031] A metabolic rate calculation module, further configured to: obtain the body surface area of each person according to the height and weight corresponding to the person, and use the production rate of the set gas under standard conditions and the respiratory quotient to determine the metabolic rate based on indirect calorimetry;

[0032] A time phase correction module, configured to: perform phase correction calculation according to the obtained metabolic rate change curve and the actual metabolic rate change curve to obtain the final human metabolic rate.

[0033] Furthermore, the indoor space is a closed space with a certain number of air changes, and the number of air changes is not greater than 0.7 times / h. The concentration of the set gas, the air temperature, and the atmospheric pressure in the indoor and outdoor environments are obtained through sensors.

[0034] Further, the sensors include indoor sensors and outdoor sensors. There are at least two groups of indoor sensors, both arranged on the wall at the center of the width of the indoor space, and the heights are respectively used to simulate the height of lying in bed and the standing height; there is at least one group of outdoor sensors, arranged at the fresh air inlet of the indoor space or in the sunshade of the outer facade of the window.

[0035] Compared with the prior art, the above one or more technical solutions have the following beneficial effects:

[0036] Regarding spaces such as building rooms or family bedrooms as indoor spaces with a certain ventilation volume, by collecting the change in gas concentration (generally the change in CO2 concentration or O2 concentration) generated by the human body in the indoor space, the human metabolic rate is predicted and calculated based on the indirect calorimetry method and the pollutant diffusion equation. Since it is carried out inside the building, the sensors can be arranged inside and outside the building, and there is no need for the test subjects to wear sensors, enabling the subjects to move freely and enabling real-time monitoring; taking advantage of the airtight performance of the building structure itself and cooperating with corresponding data processing, the calculation accuracy is high; the detection conditions are no longer limited to the laboratory environment, and an indoor space with airtightness meeting the requirements and a certain ventilation volume is sufficient, making the test and calculation process of the human metabolic rate highly portable and more convenient, and being able to provide key technologies for the development of intelligent and green living environments in the construction industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The schematic diagrams in the specification forming a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention.

[0038] Figure 1 is a schematic diagram of the human metabolic rate prediction process provided by one or more embodiments of the present invention;

[0039] Figure 2 is a schematic diagram of the architecture of the human metabolic rate prediction system provided by one or more embodiments of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0040] The present invention will be further described below in conjunction with the drawings and embodiments.

[0041] It should be noted that the following detailed descriptions are all exemplary and are intended to provide a further description of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention belongs.

[0042] As introduced in the background art, the measurement principles of common metabolic meters on the market are all indirect calorimetry methods. By wearing sensors on specific parts of the human body and collecting relevant data in a laboratory environment, the human metabolic rate of the measured person is predicted through calculation. Since this method requires the measured person to wear sensors, it is easy to restrict the free movement of the measured person and is limited to the laboratory environment, resulting in unsatisfactory convenience in the process of metabolic rate detection and prediction.

[0043] Considering the continuous improvement of building airtightness at the current stage, a family bedroom can be assumed to be an airtight room. Therefore, starting from the principle of indirect calorimetry, the indoor air composition is analyzed to predict the human metabolic rate. For example, the patent "Human Metabolic Heat Generation Measurement Device and Method Based on Carbon Dioxide Concentration Change in an Enclosed Space" (Application No.: 202110553198.6). However, there is a certain ventilation volume between the actual indoor and outdoor environments (ventilation rate of residential buildings: 0.6 times / h), and it is not an absolutely airtight space in the true sense. The calculation method based on the airtight space does not conform to the actual situation.

[0044] Therefore, the following embodiments provide a method and system for predicting human metabolic rate based on indoor and outdoor air composition. Considering the continuous improvement of building airtightness at the current stage, the building environment can be utilized. For example, a family bedroom can be assumed to be an airtight room with a certain ventilation volume. Starting from the principle of indirect calorimetry, the indoor and outdoor air composition is analyzed to predict the human metabolic rate. This method is convenient for monitoring and has a wide range of applicable scenarios, and relevant intelligent device operations can be controlled according to the obtained metabolic rate (for example, controlling the operation of the air conditioner according to the human heat demand).

[0045] Embodiment 1:

[0046] As Figure 1 - Figure 2 shown, the method for predicting human metabolic rate based on indoor and outdoor air composition includes the following steps:

[0047] Obtain the fresh air volume entering the indoor space, the number of people in the indoor space, and the height and weight of the corresponding people;

[0048] Obtain the air parameters of the indoor and outdoor environments, including the concentration of the set gas, air temperature, and atmospheric pressure;

[0049] The concentration of the set gas is unit-converted, and together with the air temperature, atmospheric pressure, and molecular weight of the set gas, the density of the set gas is obtained. Based on the indoor pollutant diffusion equation and the fresh air volume, the generation rate of the set gas by the human body in the indoor space is obtained and corrected to a value under standard conditions;

[0050] According to the height and weight corresponding to the personnel, the body surface area of each person is obtained, and the metabolic rate is determined based on the indirect calorimetry method by using the gas production rate and respiratory quotient of the set gas under standard conditions. After time-phase correction, the final human metabolic rate is obtained.

[0051] In this embodiment, the air change rate of the indoor environment ≤ 0.7 times / h.

[0052] Step 1: Determine the fresh air volume G of the room, the number n of indoor personnel, and the height H and weight m of each person. b 。

[0053] Among them, the fresh air volume of the room can be determined by on-site measurement or input by the user independently.

[0054] Step 2: Arrange indoor and outdoor sensors, both of which have the function of measuring parameters such as CO2 concentration, air temperature, and atmospheric pressure; among them, it is sufficient to have the measurement function of either CO2 concentration or O2 concentration, and the two can be mutually converted according to the respiratory quotient. Here, the detailed description is carried out taking the measurement of CO2 concentration as an example.

[0055] In this embodiment, arranging indoor and outdoor sensors specifically: taking a family bedroom as an example, considering economy, 2 indoor sensors are arranged, both on the wall at the center of the room width, with heights of 0.5 m and 1.5 m respectively, simulating the corresponding lying and standing heights; 1 outdoor sensor is arranged, which is arranged at the fresh air inlet or in the sunshade of the outer window facade of the room to avoid the influence of solar radiation on the temperature measurement function.

[0056] Step 3: Detect and record the air parameters indoors and outdoors; at intervals of 5 seconds, measure each air parameter 12 times, and take the average value of the 12 measurements as the corresponding value at that moment (min); on this basis, each indoor air parameter is the average value of the measurement values of the 2 indoor sensors.

[0057] Step 4: Perform unit conversion on the CO2 concentration at a certain moment.

[0058] Since the unit of the CO2 concentration monitored by the sensor is ppm, according to the calculation requirement, it is converted to g / m 3 , as shown in formula (1):

[0059]

[0060] In the formula, C is the indoor CO2 concentration at a certain moment, unit: g / m 3 ; N is the indoor CO2 concentration at a certain moment, unit: ppm; P is the indoor atmospheric pressure, unit: Pa; M co2 co2 is the CO2 molecular weight, taking 44; T is the thermodynamic temperature of the indoor air, K.

[0061] Step 5: Calculate the density of CO2 gas, as shown in formula (2):

[0062]

[0063] Where, ρ CO2 is the density of indoor carbon dioxide, unit: kg / m 3 ; R is the gas constant, unit: J / (mol·K), which is 8.314.

[0064] Step 6: Calculate the human body CO2 production rate based on the indoor pollutant diffusion equation and the fresh air volume. This method comprehensively considers the influence of pollutant diffusion process and outdoor gas penetration, and can more accurately calculate the human body CO2 production rate, as shown in formula (3):

[0065]

[0066] Where C i+1 with C i are the indoor CO2 concentrations at time i+1 and time i, in g / m 3 ; C o,i is the outdoor CO2 concentration at time i, unit: g / m 3 G is the fresh air volume, unit: m 3 / s; V is the room volume, unit: m 3 .

[0067] Step 7: Correct the CO2 production rate to the value under standard conditions, as shown in formula (4):

[0068]

[0069] Where p H2O is the saturated water vapor partial pressure, unit: Pa; It is the carbon dioxide production rate under standard conditions, in ml / s.

[0070] Step 8: Calculate the body surface area of each individual, as shown in formula (5):

[0071]

[0072] Where m b is body weight, unit: kg; H b is height, unit: m.

[0073] Step 9: Calculate the metabolic rate using indirect calorimetry, as shown in formula (6):

[0074]

[0075] Wherein, RQ is the respiratory quotient, taking 0.85; M is the metabolic rate, unit: W / m 2 .

[0076] Step 10, perform time-phase correction on the predicted value of the metabolic rate

[0077] Considering that the CO2 gas diffusion process takes a certain amount of time, that is, there is a certain delay time t0 between the predicted metabolic rate and the actual metabolic rate of the human body. The delay time t0 can be measured according to the specific scenario. Therefore, the actual real-time metabolic rate M r (τ - t0) = M(τ).

[0078] The above method predicts and calculates the human metabolic rate by collecting the change of CO2 concentration or O2 concentration in the room, based on the indirect calorimetry method and the pollutant diffusion equation. Since it is carried out in the building, the sensors can be arranged inside and outside the building, and there is no need to wear sensors. It has the advantages of free movement of personnel, real-time monitoring, high calculation accuracy, and strong portability, and can provide key technologies for the development of intelligent and green living environments in the construction industry.

[0079] Example 2:

[0080] A human metabolic rate prediction system based on indoor and outdoor air components, including:

[0081] An information input module, configured to: obtain the fresh air volume entering the indoor space, the number of people in the indoor space, and the corresponding height and weight of the people;

[0082] A parameter collection module, configured to: obtain the concentration of the set gas, the air temperature, and the atmospheric pressure in the indoor and outdoor environments;

[0083] A numerical processing module, configured to: convert the concentration of the set gas, and obtain the density of the set gas with the air temperature, the atmospheric pressure, and the molecular weight of the set gas. Based on the indoor pollutant diffusion equation, obtain the generation rate of the set gas by the human body in the indoor space, and correct and process it to a value under standard conditions;

[0084] A metabolic rate calculation module, further configured to: obtain the body surface area of each person according to the corresponding height and weight of the person, and use the generation rate of the set gas under standard conditions and the respiratory quotient to determine the metabolic rate based on the indirect calorimetry method;

[0085] A time-phase correction module, configured to: perform phase correction calculation according to the obtained metabolic rate change curve and the actual metabolic rate change curve to obtain the final human metabolic rate.

[0086] In this embodiment, the information input module is configured to: collect the fresh air volume G, the number of people n, the height H, and the weight m input by the user b .

[0087] In this embodiment, the parameter acquisition module is configured to: acquire air parameters of the indoor and outdoor environments, including CO2 concentration, air temperature, atmospheric pressure, etc.

[0088] The data storage module is configured to: store the input information and the acquired parameter data.

[0089] The calculation module is configured to: perform an average calculation on the air data of the indoor and outdoor environments;

[0090] The calculation module is further configured to: perform a unit conversion calculation on the CO2 concentration;

[0091] The calculation module is further configured to: calculate the CO2 gas density;

[0092] The calculation module is further configured to: calculate the human CO2 production rate;

[0093] The calculation module is further configured to: perform a standard condition correction calculation on the CO2 production rate;

[0094] The calculation module is further configured to: calculate the human metabolic rate.

[0095] The time-phase correction module is configured to: perform a phase correction calculation on the measured metabolic rate change curve and the actual metabolic rate change curve.

[0096] By collecting the change in CO2 concentration or O2 concentration in a sealed room, the human metabolic rate is predicted and calculated based on the indirect calorimetry method and the pollutant diffusion equation. Since it is carried out in a building, the sensors can be arranged inside and outside the building, and there is no need to wear sensors. It has the advantages of free movement of personnel, real-time monitoring, high calculation accuracy, and strong portability, and can provide key technologies for the development of intelligent and green living environments in the construction industry.

[0097] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for predicting human metabolic rate based on indoor and outdoor air components, characterized in that, It includes the following steps: Obtain the fresh air volume entering the indoor space, the number of people in the indoor space, and the height and weight corresponding to each person; Obtain the concentration of the set gas, the air temperature, and the atmospheric pressure in the indoor and outdoor environments; The concentration of the set gas is unit-converted, and together with the air temperature, the atmospheric pressure, and the molecular weight of the set gas, the density of the set gas is obtained. Based on the indoor pollutant diffusion equation, the generation rate of the set gas by the human body in the indoor space is obtained and corrected to the value under standard conditions. The generation rate of the set gas by the human body is as shown in the following formula: Wherein, and are the concentrations of the indoor set gas X at the (i + 1)-th and i-th moments respectively, V is the volume of the indoor space, is the concentration of the outdoor set gas X at the i-th moment, g / m3, is an infinitesimal time interval, is the density of the set gas X, and G is the fresh air volume of the room; According to the height and weight corresponding to the person, the body surface area of each person is obtained, and using the generation rate of the set gas under standard conditions and the respiratory quotient, the metabolic rate is determined based on the indirect calorimetry method. After time-phase correction, the final human metabolic rate is obtained.

2. The method for predicting human metabolic rate based on indoor and outdoor air components according to claim 1, wherein The set gas includes carbon dioxide or oxygen.

3. The human metabolic rate prediction method based on indoor and outdoor air components according to claim 1, wherein Unit conversion, specifically: set the unit of the gas concentration to ppm, and convert it to g / m according to the indoor atmospheric pressure and the molecular weight corresponding to the gas 3 .

4. The method for predicting human metabolic rate based on indoor and outdoor air components according to claim 1, characterized in that, The concentration of the set gas is unit-converted, and together with the air temperature, the atmospheric pressure, and the molecular weight of the set gas, the density of the set gas is obtained, as shown in the following formula: ； In the formula, is the set density of gas X, P is the atmospheric pressure, in Pa; is the set molecular weight of gas X, is the gas constant, T is the thermodynamic temperature.

5. The method for predicting human metabolic rate based on indoor and outdoor air components according to claim 1, wherein The metabolic rate is determined based on the indirect calorimetry method, as shown in the following formula: ； In the formula, is the respiratory quotient, M is the metabolic rate, is the production rate of gas X by the human body under standard conditions, is the body surface area of the human body.

6. The method for predicting human metabolic rate based on indoor and outdoor air components according to claim 1, wherein The time-phase correction is specifically: determine the delay time t0 required for the diffusion process of gas X, and the corrected metabolic rate is 。 7. A system for implementing the human metabolic rate prediction method according to any one of claims 1-6, characterized in that, It includes: An information input module, configured to: obtain the fresh air volume entering the indoor space, the number of people in the indoor space, and the height and weight corresponding to the people; A parameter acquisition module, configured to: obtain the concentration of the set gas, the air temperature, and the atmospheric pressure in the indoor and outdoor environments; A numerical processing module, configured to: the concentration of the set gas is unit-converted, and together with the air temperature, the atmospheric pressure, and the molecular weight of the set gas, the density of the set gas is obtained. Based on the indoor pollutant diffusion equation, the generation rate of the set gas by the human body in the indoor space is obtained and corrected to the value under standard conditions. The generation rate of the set gas by the human body is as shown in the following formula: In the formula, and are the concentrations of the indoor set gas X at the (i + 1)-th and i-th moments respectively, V is the volume of the indoor space, is the concentration of the outdoor set gas X at the i-th moment, in g / m3, is an infinitesimal time interval, is the density of the set gas X, and G is the fresh air volume of the room; A metabolic rate calculation module, further configured to: according to the height and weight corresponding to the person, obtain the body surface area of each person, and use the generation rate of the set gas under standard conditions and the respiratory quotient to determine the metabolic rate based on the indirect calorimetry method; A time-phase correction module, configured to: perform phase correction calculation according to the obtained metabolic rate change curve and the actual metabolic rate change curve to obtain the final human metabolic rate.

8. The system for predicting the human metabolic rate according to claim 7, wherein, The indoor space is a closed space with a certain number of air changes, and the number of air changes is not greater than 0.7 times / h. The concentration of the set gas, the air temperature, and the atmospheric pressure in the indoor and outdoor environments are obtained through sensors.

9. The system of the human metabolic rate prediction method according to claim 8, wherein, The sensors include indoor sensors and outdoor sensors. There are at least two groups of indoor sensors, both arranged on the wall at the center of the width of the indoor space, and the heights are respectively used to simulate the lying height and the standing height; there is at least one group of outdoor sensors, arranged at the fresh air inlet of the indoor space or in the shaded area on the outer facade of the window.

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