Method and device for evaluating the thermal insulation and heat gain performance of a building

Abstract

The application relates to a building heat preservation and heat gain performance evaluation method and device. In an evaluation period, a time period with the maximum day and night temperature difference and the minimum average temperature change in a non-heating period is selected as an evaluation time period, and the return water temperature of a heating system of a set room in the building is obtained in the evaluation time period; the ratio between the return water temperature change amount and the corresponding air temperature change amount during a set time interval in the evaluation time period is calculated as the heat transfer coefficient of the room, and the heat transfer coefficient of the corresponding building is obtained after averaging; in an evaluation period, a time period with the longest continuous illumination time in a non-heating period is selected as an evaluation time period, and the return water temperature of a heating system of a set room in the building is obtained in the evaluation time period; the difference between the average return water temperature and the corresponding average air temperature during a set time interval in the evaluation time period is calculated as the heat gain temperature difference of the room, and the heat gain temperature difference of the corresponding building is obtained after averaging.

Description

Technical Field

[0001] This invention relates to the field of building energy conservation technology, specifically to a method and apparatus for evaluating the thermal insulation and heat gain performance of buildings. Background Technology

[0002] The statements in this section are merely background information related to the present invention and do not necessarily constitute prior art.

[0003] The thermal insulation and heat gain performance of buildings are parameters for evaluating the operational effectiveness of urban centralized heating systems and are performance parameters that heating companies pay close attention to.

[0004] Among them, thermal insulation performance is related to the rate at which heat supplied to a building is lost to the surrounding air. The better the thermal insulation performance, the slower the heat dissipation rate, and the less sensitive the indoor temperature is to changes in the outdoor temperature. Heating companies can supply heat to the building with a smaller and relatively stable heat load. The worse the thermal insulation performance, the faster the heat dissipation rate, and heating companies need to adjust the heat load in a timely manner according to changes in the temperature to maintain a relatively stable indoor temperature.

[0005] Heat gain performance is related to a building’s ability to obtain heat from the surrounding environment, such as sunlight and soil heat transfer. For example, the larger the area of ​​the building’s sun-facing side, the stronger its ability to obtain additional heat. The more heat a building obtains through sunlight and other means, the lower its heat load. The less heat gain, the higher its heat load.

[0006] Traditional methods for estimating building insulation performance rely on theoretical calculations based on data such as the building's exterior wall materials, wall thickness and composition, window size, and insulation conditions. This method has the following drawbacks:

[0007] 1. As buildings are used, the original design data may become unavailable, or the building materials used in actual construction may not be entirely consistent with the design data; the performance of insulation materials in existing buildings that have been used for many years may differ from the design data; some buildings may have undergone renovation, refurbishment, or additional external wall insulation in the later stages of use, resulting in a significant discrepancy between theoretical data and actual conditions.

[0008] 2. The insulation conditions vary in different parts of the building. For example, the top and bottom floors have poorer insulation, while the middle floors have better insulation. Traditional calculation methods for the insulation of the entire building fail to provide a detailed estimate for each individual resident.

[0009] 3. Due to significant deviations in traditional calculation methods, the industry generally uses general terms like "one-step," "two-step," "three-step," and "four-step energy-saving building" to describe building insulation. Some regions also roughly use the building's age to describe its insulation, with older buildings considered to have poorer insulation. These methods are too crude in practice and cannot meet the requirements of refined management. For example, in many projects, even among three-step energy-saving buildings under the same heat load, there are significant differences in indicators such as room temperature, complaint rate, and resident satisfaction.

[0010] Heating companies have realized in practice that the original method of classifying energy consumption in several steps was too crude. Therefore, in recent years, they have adopted a method of judging building insulation characteristics by using indoor temperature sensors installed in households. If the indoor temperature remains high and stable when the outdoor temperature drops sharply, the building is considered to have good insulation; otherwise, it is considered to have poor insulation. This method has the following drawbacks:

[0011] 1. Limited number of room temperature data acquisition devices installed. Due to limitations in the cost of room temperature data acquisition devices, compatibility with the original heating system, and residents' resistance, comprehensive installation coverage is difficult to achieve.

[0012] 2. The data from the room temperature data acquisition device is distorted. Because the room temperature data acquisition device is installed indoors, it is susceptible to data distortion due to various factors such as the user's mobile device, open windows, sunlight exposure, and differences in installation location, making it difficult to accurately reflect the building's insulation status.

[0013] 3. Due to the heating season, room temperature is affected by various factors such as heat supply, room temperature changes, and heat conduction between households, making it difficult to accurately reflect the building's insulation performance. Only a qualitative evaluation of insulation performance is possible, and quantitative assessment is not feasible.

[0014] The assessment of a building's heat gain capacity is far more rudimentary than its insulation performance. It is typically based on qualitative evaluation, such as whether the building faces the sun or the shade, or whether it has more sunny or shady sides. Assessors often arrive at binary conclusions based on their subjective feelings, leading to significant arbitrariness and chance. Summary of the Invention

[0015] To address the technical problems mentioned above, this invention provides a method and apparatus for evaluating the thermal insulation and heat gain performance of buildings. By using the return water temperature information during the non-heating season, the heat transfer coefficient and heat gain temperature difference of the building are obtained, which are used as parameters to demonstrate the thermal insulation and heat gain performance of the building. This can help heating companies select heating modes and heating control strategies based on different parameters during the heating season, replacing the original purely theoretical calculations or heating season estimations.

[0016] To achieve the above objectives, the present invention adopts the following technical solution:

[0017] The first aspect of the present invention provides a method for evaluating the thermal insulation and heat gain performance of a building, comprising the following steps:

[0018] Within an evaluation period, the time period with the largest diurnal temperature difference and the smallest average temperature change during the non-heating season is selected as the evaluation period. The return water temperature of the heating system in the designated rooms of the building is obtained within the evaluation period.

[0019] During the evaluation period, the ratio between the change in return water temperature and the corresponding change in air temperature during the set time interval is calculated as the heat transfer coefficient of the room. After averaging, the heat transfer coefficient of the corresponding building is obtained to demonstrate the thermal insulation performance of the building.

[0020] Within an evaluation period, the time period with the longest continuous sunshine duration during the non-heating season is selected as the evaluation period. During the evaluation period, the return water temperature of the heating system in the designated rooms of the building is obtained.

[0021] During the evaluation period, the difference between the average return water temperature and the corresponding average air temperature during the set time interval is calculated as the heat gain temperature difference of the room. After averaging, the heat gain temperature difference of the corresponding building is obtained to demonstrate the heat gain performance of the building.

[0022] The return water temperature is obtained using the building's existing heating system.

[0023] The return water temperature obtained during the non-heating season reflects the temperature inside the building's pipe shaft, which is the temperature of the building itself.

[0024] The heat transfer coefficient of a building is obtained by averaging the heat transfer coefficients of its rooms, as follows:

[0025] During the evaluation period, the average heat transfer coefficient of multiple rooms over the set time interval is the heat transfer coefficient of the corresponding resident in that room.

[0026] The average heat transfer coefficient of all households is the heat transfer coefficient of the building corresponding to each household.

[0027] The heat gain temperature difference of a given room within a building is averaged to obtain the corresponding heat gain temperature difference of the building itself. Specifically:

[0028] During the evaluation period, the average heat gain temperature difference of multiple rooms over the set time interval is the heat gain temperature difference of the corresponding resident in that room.

[0029] The average heat gain temperature difference for all households is the heat gain temperature difference of the building corresponding to each household.

[0030] When the heat gain temperature difference is positive, it means that the building absorbs more heat through sunlight than it loses through air conduction and soil conduction.

[0031] When the heat gain temperature difference is negative, it means that the heat absorbed by the building through sunlight is less than the heat lost through air conduction and soil conduction.

[0032] A second aspect of the present invention provides an apparatus for evaluating the thermal insulation and heat gain performance of a building, comprising a processor that executes the evaluation method described above.

[0033] Compared with existing technologies, one or more of the above technical solutions have the following beneficial effects:

[0034] 1. During the non-heating season, the return water temperature collected by the existing heating system is used as the building's body temperature, which eliminates the influence of the building insulation material performance. At the same time, it avoids the influence of various factors such as heat supply, room temperature changes, and conduction between heating households during the heating season, making the evaluation of insulation performance more accurate. The evaluation of heat gain performance is based on the heat gain temperature difference calculated from the return water temperature, which reduces the randomness and chance of traditional methods and is conducive to quantitative evaluation.

[0035] 2. The data is more comprehensive. Compared with the current collection of room temperature data, collecting the return water temperature of the existing heating system can collect the temperature data of each user in the building, and can make a detailed evaluation of the thermal insulation performance of different locations in the building.

[0036] 3. The data is authentic and accurate. Collecting data from inside the pipe well during the non-heating season can avoid various external and human interference factors that would occur during the heating season when collecting room temperature data.

[0037] 4. Low investment: Data is collected using existing heat metering facilities, and no additional hardware equipment is required. The investment is basically only the electricity cost and labor maintenance cost of the system during the non-heating season.

[0038] 5. The heating season spans a long period. In severely cold regions, the heating season ends in mid-April and begins in late October; in colder regions, the heating season ends in late March and begins in mid-November. There is a 7-8 month non-heating season each year, covering the warming phase (April-June), the phase of large diurnal temperature differences (July-August), and the cooling phase (September-October). By assessing the characteristics of buildings at different stages, accurate data on insulation and heat gain performance can be obtained. Attached Figure Description

[0039] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0040] Figure 1 This is a flowchart of the evaluation process for building thermal insulation and heat gain performance provided by one or more embodiments of the present invention;

[0041] Figure 2This is a schematic diagram of the curve showing the fluctuation of the return water temperature of room 1 in community A with the change of air temperature, provided by one or more embodiments of the present invention;

[0042] Figure 3 This is a schematic diagram showing the fluctuation of the return water temperature of room 2 in community A with the change of air temperature, provided by one or more embodiments of the present invention;

[0043] Figure 4 This is a schematic diagram of a curve showing the fluctuation of the return water temperature of a room in Community B with the change of air temperature, provided by one or more embodiments of the present invention.

[0044] Figure 5 This is a schematic diagram showing the fluctuation of the return water temperature of a room in Community C as a function of air temperature, provided by one or more embodiments of the present invention. Detailed Implementation

[0045] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0046] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0047] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0048] As described in the background section, current methods for evaluating the thermal insulation and heat gain performance of buildings are too crude and cannot provide quantitative evaluation results. Therefore, the following embodiments provide a method for evaluating the thermal insulation and heat gain performance of buildings. By using the return water temperature information during the non-heating season, the building's heat transfer coefficient and heat gain temperature difference are obtained, which are used as parameters to demonstrate the building's thermal insulation and heat gain performance. This method allows for the selection of heating modes and heating control strategies based on different parameters during the heating season, replacing the original purely theoretical calculations or heating season estimations.

[0049] Example 1:

[0050] like Figure 1 As shown, a method for evaluating the thermal insulation and heat gain performance of a building includes the following steps:

[0051] Within an evaluation period, the time period with the largest diurnal temperature range and the smallest average temperature change during the non-heating season is selected as the evaluation period. The return water temperature of the heating system in the designated rooms of the building is obtained within the evaluation period.

[0052] During the evaluation period, the ratio between the change in return water temperature and the corresponding change in air temperature during the set time interval is calculated as the heat transfer coefficient of the room. After averaging, the heat transfer coefficient of the corresponding building is obtained to demonstrate the thermal insulation performance of the building.

[0053] Within an evaluation period, the time period with the longest continuous sunshine duration during the non-heating season is selected as the evaluation period. During the evaluation period, the return water temperature of the heating system in the designated rooms of the building is obtained.

[0054] During the evaluation period, the difference between the average return water temperature and the corresponding average air temperature during the set time interval is calculated as the heat gain temperature difference of the room. After averaging, the heat gain temperature difference of the corresponding building is obtained to demonstrate the heat gain performance of the building.

[0055] Specifically:

[0056] With the continuous promotion and installation of heat metering equipment, buildings will gradually install heat metering devices, such as heat meters, on / off control valves, and flow regulating valves. Many of these devices are equipped with return water temperature measurement functions. For example, heat meters require inlet and outlet water temperature measurements to calculate heat output, and flow regulating valves require return water temperature measurements to accurately regulate the hydraulic balance between households. During the non-heating season, the heating pipes are either empty or filled with water; in this case, the return water temperature reflects the temperature of the building's pipe shafts. When there is no heating, the return water temperature can be considered to reflect the building's temperature. This embodiment evaluates the building's insulation and heat gain performance by studying the return water temperature data collected by the aforementioned heat metering devices during the non-heating season.

[0057] (1) Methods for evaluating the thermal insulation properties of buildings

[0058] We selected a period of stable average temperature with a large daily temperature difference to assess how the building temperature follows drastic temperature changes, and used this data to evaluate the building's thermal insulation characteristics.

[0059] The following is a comparative experiment: one is an older residential community without external wall insulation, and the other is a newly built residential community with external wall insulation and less than ten years old. Analysis of climate data for a certain region revealed that the diurnal temperature range is significant in June and July; therefore, data was analyzed during this period.

[0060] Community A is an old community with poor exterior wall insulation. Figure 2This is a graph showing the return water temperature versus air temperature (outdoor temperature) curves for a specific room (room 1) in this residential complex, obtained at set intervals from mid-May to mid-July. The vertical axis represents the temperature value, and the horizontal axis represents the set sampling time points. Figure 2 The data (35 sampling times were evenly selected between mid-May and mid-July) shows that the change in return water temperature is highly correlated with the change in air temperature (the trends are similar). This data indicates that the building's thermal insulation performance is poor and the building temperature fluctuates drastically with changes in air temperature.

[0061] Other residents in the building also reported similar situations, albeit to slightly different degrees. Figure 3 This is data from another room (room 2) in the same building. Figure 3 The vertical axis represents the temperature value, and the horizontal axis represents approximately 105 sampling time points selected evenly over a period of time. During a certain sampling time point, as the air temperature dropped from 34℃ to 17℃, the return water temperature dropped from 27℃ to 22℃.

[0062] Figure 4 The data shows the outdoor temperature and return water temperature of Community B in a certain area over a period of time. The data shows that the temperature of the building is relatively stable, and the return water temperature is not affected by the instantaneous air temperature, but only changes slowly under the influence of the average temperature over many days. Through on-site inspection, it was found that the community is a newly built community with good insulation. The data of other residents in the community are similar.

[0063] Based on the above observations, the following algorithm is proposed as a quantitative evaluation method for the thermal insulation properties of buildings:

[0064] 1. During the non-heating season, select the 15 days with the largest diurnal temperature range and the smallest average temperature variation as the assessment period. This period is generally from June to August.

[0065] 2. The heat transfer coefficients between the building temperature and the air temperature are calculated at 24-hour intervals as follows:

[0066] Heat transfer coefficient = (change in return water temperature) / (change in air temperature)

[0067] 3. The average heat transfer coefficient for each day within a 15-day period is the heat transfer coefficient of that household.

[0068] 4. The average heat transfer coefficient of all residents is the heat transfer coefficient of the building.

[0069] The obtained building heat transfer coefficient is used as the basis for demonstrating the building's thermal insulation properties.

[0070] (2) Evaluation method for building heat gain characteristics

[0071] The heat gain characteristics of a building are assessed by evaluating its ability to gain heat through sunlight and soil conduction, and are determined by analyzing the relationship between the average air temperature and the average return water temperature of the building.

[0072] For example Figure 5 The data is from a room in Community C of a certain region. It can be seen that during the set sampling period, the building temperature (return water temperature) was always higher than the air temperature (outdoor temperature), indicating that the building can effectively obtain external heat through sunlight and good external wall insulation.

[0073] The heat gain characteristics of a building are calculated using the following methods:

[0074] 1. Select the 15-day period with the most sunshine (most sunny days), generally from June to August;

[0075] 2. Calculate the difference between the 24-hour average air temperature and the average return water temperature:

[0076] Heat gain temperature difference = Average return water temperature - Average air temperature

[0077] 3. Calculate the average daily temperature difference for this household over 15 days;

[0078] 4. The average value of all residents in the building is the overall heat gain temperature difference of the building.

[0079] The overall heat gain temperature difference of a building serves as a basis for demonstrating its heat gain performance.

[0080] A positive heat gain temperature difference indicates that the building absorbs more heat through sunlight than it loses through conduction through the air and soil; conversely, a negative heat gain temperature difference indicates that the building absorbs less heat through sunlight than it loses through conduction through the air and soil.

[0081] The above method has the following advantages:

[0082] 1. Comprehensive data: Compared with the current collection of room temperature data, data based on the return water temperature of the heating system can be collected from each household, which can make a detailed evaluation of the thermal insulation performance of different locations in the building;

[0083] 2. Accurate and reliable data: Collecting data from inside the pipe well during the non-heating season avoids various external and human interference factors that would affect room temperature data collection during the heating season.

[0084] 3. Low investment: Data is collected using existing heat metering facilities, without the need for additional hardware installation. The investment is basically only the electricity cost and labor maintenance cost of the system during the non-heating season.

[0085] 4. Long time span: In severely cold regions, the heating season ends in mid-April and begins in late October; in cold regions, the heating season ends in late March and begins in mid-November. Each year has a 7-8 month non-heating season covering the warming phase (April-June), the phase of large diurnal temperature differences (July-August), and the cooling phase (September-October). Accurate data on insulation and heat gain performance can be obtained by assessing the characteristics of buildings at different stages.

[0086] Example 2:

[0087] An evaluation device for building insulation and heat gain performance includes a processor that executes the evaluation method in Embodiment 1.

[0088] The evaluation method executed by the processor uses the return water temperature information during the non-heating season to derive the building's heat transfer coefficient and heat gain temperature difference, which serve as parameters to demonstrate the building's insulation and heat gain performance. This helps heating companies select heating modes and heating control strategies based on different parameters during the heating season, replacing the original purely theoretical calculations or heating season estimations.

[0089] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for evaluating the thermal insulation and heat gain performance of a building, characterized in that: Includes the following steps: Within an evaluation period, the time period with the largest diurnal temperature difference and the smallest average temperature change during the non-heating season is selected as the evaluation period. During the evaluation period, the return water temperature of the heating system of the designated rooms in the building is obtained. During the evaluation period, the ratio between the change in return water temperature and the corresponding change in air temperature during the set time interval is calculated as the heat transfer coefficient of the room. After averaging, the heat transfer coefficient of the corresponding building is obtained to demonstrate the building's thermal insulation performance. Within an evaluation period, the time period with the longest continuous sunshine duration during the non-heating season is selected as the evaluation period. During the evaluation period, the return water temperature of the heating system in the designated rooms of the building is obtained. During the evaluation period, the difference between the average return water temperature and the corresponding average air temperature during the set time interval is calculated as the heat gain temperature difference of the room. After averaging, the heat gain temperature difference of the corresponding building is obtained to demonstrate the heat gain performance of the building.

2. The method for evaluating the thermal insulation and heat gain performance of a building as described in claim 1, characterized in that: The return water temperature is obtained using the building's existing heating system.

3. The method for evaluating the thermal insulation and heat gain performance of a building as described in claim 1, characterized in that: The return water temperature obtained during the non-heating season reflects the temperature inside the building's pipe shaft, which is the temperature of the building itself.

4. The method for evaluating the thermal insulation and heat gain performance of a building as described in claim 1, characterized in that: The heat transfer coefficient of a building is obtained by averaging the heat transfer coefficients of its rooms, including: During the evaluation period, the average heat transfer coefficient of each room in multiple rooms over the set time interval is the heat transfer coefficient of the corresponding resident in that room.

5. The method for evaluating the thermal insulation and heat gain performance of a building as described in claim 4, characterized in that: The heat transfer coefficient of a building is obtained by averaging the heat transfer coefficients of rooms within the building, and also includes: The average heat transfer coefficient of all households is the heat transfer coefficient of the building corresponding to each household.

6. The method for evaluating the thermal insulation and heat gain performance of a building as described in claim 1, characterized in that: The heat gain temperature difference of a given room in a building is averaged to obtain the corresponding heat gain temperature difference of the building, including: During the evaluation period, the average heat gain temperature difference of each room in multiple rooms over the set time interval is the heat gain temperature difference of the corresponding resident in that room.

7. The method for evaluating the thermal insulation and heat gain performance of a building as described in claim 6, characterized in that: The heat gain temperature difference of a building is obtained by averaging the heat gain temperature difference of a room within the building, and also includes: The average heat gain temperature difference for all households is the heat gain temperature difference of the building corresponding to each household.

8. The method for evaluating the thermal insulation and heat gain performance of a building as described in claim 1, characterized in that: When the heat gain temperature difference is positive, it means that the heat absorbed by the building through sunlight is greater than the heat lost through air conduction and soil conduction.

9. The method for evaluating the thermal insulation and heat gain performance of a building as described in claim 1, characterized in that: When the heat gain temperature difference is negative, it means that the heat absorbed by the building through sunlight is less than the heat lost through air conduction and soil conduction.

10. An evaluation device for the thermal insulation and heat gain performance of a building, characterized in that: Includes a processor that performs the method as described in claim 1.

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