A high-temperature and low-temperature heat supply method for a cabinet air conditioner with high efficiency by alternating switching of hot air

Abstract

The application discloses a high-temperature and low-temperature heat supply alternating switching cabinet air conditioner high-efficiency heat supply method, which is characterized in that: a wind guide pipe is connected at an air inlet of the cabinet air conditioner, so that the cabinet air conditioner can utilize the wind from the upper space of a room through the wind guide pipe, and then alternately utilize high-temperature heat supply generated by the air conditioner to provide heat for the room, and utilize low-temperature heat supply to transfer the heat accumulated in the upper space of the room due to thermal buoyancy to the lower space of the room where a personnel activity area is located, so as to realize the heat reutilization of the upper space of the room for creating the heat environment of the lower space of the room. The embodiment shows that the application reduces the air conditioner energy consumption by 53.6%, and reduces the head-to-foot temperature difference of the sitting and standing postures by 59.0% and 50.3% respectively.

Description

Technical Field

[0001] This invention belongs to the field of air conditioning and heating technology, and specifically relates to a high-efficiency heating method for cabinet air conditioners that alternates between high-temperature and low-temperature hot air supply. Background Technology

[0002] Winter heating is essential for creating a comfortable thermal environment. However, winter heating consumes a significant amount of energy, making it a key area for energy conservation and emission reduction in the building sector. On-demand heating is a major technological approach for high-efficiency heating.

[0003] There are two main types of heating: radiant and convection. Radiant heating creates a uniform thermal environment and offers high comfort, but its slow thermal response makes it unsuitable for on-demand heating. Convection heating has a fast thermal response and is suitable for on-demand heating. Air conditioning is the most common form of convection heating and is widely used in residential and office buildings.

[0004] However, the heat waste and thermal discomfort caused by the thermal buoyancy of air conditioning convection heating urgently need to be addressed. Because the hot air supplied by convection heating is subject to thermal buoyancy, it drifts towards the upper part of the room, causing heat to accumulate there. This accumulated heat cannot be used to create a suitable thermal environment in the work area, resulting in wasted energy from the supplied air and low thermal efficiency in creating a comfortable work environment. Furthermore, the accumulated heat in the upper part of the room creates thermal stratification, leading to excessive temperature differences between the head and feet, causing thermal discomfort.

[0005] Floor-standing air conditioners are one of the most common types of air conditioners. Floor-standing air conditioners stand on the ground and generally have a stronger heating capacity than wall-mounted air conditioners. This means that the heat accumulates in the upper part of the room, causing discomfort due to the temperature difference between the head and feet, as well as high energy consumption, which are problems that urgently need to be addressed. Summary of the Invention

[0006] To overcome the aforementioned problems in the prior art, the present invention aims to provide a high-efficiency heating method for cabinet air conditioners that alternates between high-temperature and low-temperature hot air supply. This method alternately utilizes high-temperature hot air generated by the air conditioner to provide heat to the room, and uses low-temperature hot air supply to transfer heat accumulated in the upper space of the room due to thermal buoyancy to the lower space of the room where people are active. This enables the reuse of heat in the upper space of the room to create a thermal environment in the lower space of the room, thereby reducing air conditioning energy consumption. At the same time, it reduces the head-to-toe temperature difference and improves thermal comfort.

[0007] To achieve the above objectives, the technical solution of the present invention is as follows:

[0008] A high-efficiency heating method for cabinet air conditioners that alternates between high-temperature and low-temperature hot air supply modes is disclosed. The cabinet air conditioner alternates between a high-temperature hot air supply mode and a low-temperature hot air supply mode. In the high-temperature hot air supply mode, the air conditioner generates heat to heat the room. In the low-temperature hot air supply mode, no air conditioner heating is required. The low-temperature hot air supply mode reuses the hot air that has accumulated in the upper space of the room due to thermal buoyancy in the high-temperature hot air supply mode to create heat in the lower space of the room where people are active, thereby reducing the thermal discomfort caused by the head-to-toe temperature difference and improving the heating efficiency of the air conditioner.

[0009] Connect an air duct to the air inlet of the cabinet air conditioner so that the air conditioner draws air from the upper part of the room.

[0010] In high-temperature hot air supply mode, the indoor air entering the air conditioner is heated by the air conditioner and then blown from the air conditioner outlet to the lower part of the room where people are active. The air supply angle and speed of high-temperature hot air supply are determined according to thermal comfort standards or people's thermal preferences. The indoor air entering the air conditioner comes from the upper space of the room through the air duct or from the air inlet of a conventional cabinet air conditioner.

[0011] In low-temperature hot air supply mode, the air conditioner's air inlet draws air from the upper part of the room into the air conditioner through the air duct. The air entering the air conditioner is hot air that has been heated by the air conditioner in high-temperature hot air supply mode due to thermal buoyancy and has accumulated in the upper part of the room. In low-temperature air supply mode, it does not need to be heated by the air conditioner and is blown from the air conditioner outlet to the lower part of the room where people are active. The air supply angle and speed of low-temperature hot air supply are determined according to thermal comfort standards or people's thermal preferences.

[0012] The higher the air supply speed in the low-temperature hot air supply mode, the more hot air from the upper part of the room is delivered to the lower part of the room where people are active, but this increases the air velocity in the people's activity area. The maximum air supply speed in the low-temperature hot air supply mode is determined based on the limit value of the air velocity in the people's activity area caused by the low-temperature hot air supply mode. The limit value of the air velocity in the people's activity area is determined based on thermal comfort standards or people's thermal preferences.

[0013] The longer the low-temperature hot air supply mode operates compared to the high-temperature hot air supply mode, the higher the air conditioning energy efficiency. However, because the heat transferred from the upper part of the room is insufficient to offset the cold air entering the activity area from the outside, the temperature in the activity area decreases. The operating time of the low-temperature hot air supply mode compared to the high-temperature hot air supply mode is determined by the limit value of the air temperature in the activity area, which is determined based on thermal comfort standards or people's thermal preferences.

[0014] Compared with the prior art, the advantages of the present invention are:

[0015] (1) This invention innovatively proposes a low-temperature hot air delivery mode for cabinet air conditioners, using cabinet air conditioners as heat transfer devices to transfer the hot air heated by the air conditioner during the high-temperature hot air delivery mode, which is concentrated in the upper space of the room due to thermal buoyancy, to the bottom space of the room where people are active, thereby alleviating the problem of excessive head-to-toe temperature difference and improving the utilization efficiency of the hot air generated by the air conditioner heating mode.

[0016] (2) The present invention utilizes the alternating switching of high temperature hot air supply mode and low temperature hot air supply mode to make the cabinet air conditioner conveniently integrate two major functions: (1) air conditioning heating; (2) heat transfer from the upper space of the room to the bottom space of the room where the people's activity area is located.

[0017] (3) The heat transfer function of the low temperature hot air supply mode not only increases the heat utilization efficiency of the cabinet air conditioner, but also the cabinet air conditioner does not need to heat under the low temperature hot air supply mode, which greatly reduces the heating time of the cabinet air conditioner and further reduces the heating energy consumption of the cabinet air conditioner.

[0018] In summary, this invention achieves the reuse of heat in the upper part of the room by alternately using high-temperature hot air generated by air conditioning to provide heat to the room, and by using low-temperature hot air to transfer heat accumulated in the upper part of the room to the lower part of the room where people are active. This creates a better thermal environment in the lower part of the room, thereby reducing the energy consumption of air conditioning. At the same time, this method can also reduce the temperature difference between the head and feet, improving thermal comfort. Attached Figure Description

[0019] Figure 1 This is a physical image of the cabinet unit according to an embodiment of the present invention.

[0020] Figure 2 This is a plan view of an embodiment of the present invention.

[0021] Figure 3 This is a graph showing the measured inlet / outlet air temperature and air velocity of the air conditioner according to an embodiment of the present invention. Figure 3 (a) in the text represents the existing method. Figure 3 (b) in the figure is the method of the present invention.

[0022] Figure 4 This is a diagram showing the air temperature and air velocity along the L1 measuring line in an embodiment of the present invention. Figure 4 (a) in the figure is a temperature diagram using the existing method. Figure 4 (b) in the figure is the velocity plot of the existing method. Figure 4 (c) in the figure represents the temperature diagram of the method of the present invention. Figure 4 (d) in the figure represents the speed diagram of the method of the present invention.

[0023] Figure 5 This is a diagram showing the air temperature and air velocity along the L2 measuring line in an embodiment of the present invention. Figure 5 (a) in the figure is a temperature diagram using the existing method. Figure 5 (b) in the figure is the velocity plot of the existing method. Figure 5 (c) in the figure represents the temperature diagram of the method of the present invention. Figure 5 (d) in the figure represents the speed diagram of the method of the present invention.

[0024] Figure 6 This is a diagram showing the air temperature and air velocity along the L3 measuring line in an embodiment of the present invention. Figure 6 (a) in the figure is a temperature diagram using the existing method. Figure 6 (b) in the figure is the velocity plot of the existing method. Figure 6 (c) in the figure represents the temperature diagram of the method of the present invention. Figure 6 (d) in the figure represents the speed diagram of the method of the present invention.

[0025] Figure 7 This is a diagram showing the air temperature and air velocity along the L4 measuring line in an embodiment of the present invention. Figure 7 (a) in the figure is a temperature diagram using the existing method. Figure 7 (b) in the figure is the velocity plot of the existing method. Figure 7 (c) in the figure represents the temperature diagram of the method of the present invention. Figure 7 (d) in the figure represents the speed diagram of the method of the present invention.

[0026] Figure 8 This is a diagram of the air temperature difference along the L1-L4 measuring lines in an embodiment of the present invention.

[0027] Figure 9 This is a power consumption diagram of the embodiments of the invention and the existing methods. Detailed Implementation

[0028] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0029] This invention provides a high-efficiency heating method for cabinet air conditioners that alternates between high-temperature and low-temperature hot air supply. This method alternately uses high-temperature hot air generated by the air conditioner to provide heat to the room, and uses low-temperature hot air to transfer the heat accumulated in the upper space of the room due to thermal buoyancy to the lower space of the room where people are active. This realizes the reuse of heat in the upper space of the room to create a thermal environment in the lower space of the room, thereby reducing the energy consumption of the air conditioner. In addition, this method can reduce the temperature difference between the head and feet and improve thermal comfort.

[0030] Example

[0031] Specific implementation scenarios of the present invention are as follows Figure 1 and 2 The image shows a living room scene set up inside a laboratory environment chamber.

[0032] A high-efficiency heating method for cabinet air conditioners that alternates between high-temperature and low-temperature hot air supply modes is disclosed. The cabinet air conditioner alternates between a high-temperature hot air supply mode and a low-temperature hot air supply mode. The high-temperature hot air supply mode is generated by the air conditioner's heating function to heat the room. The low-temperature hot air supply mode does not require air conditioning heating. In the low-temperature hot air supply mode, the hot air accumulated in the upper space of the room due to the thermal buoyancy of the hot air supply is reused to create heat in the lower space of the room where people are active, thereby reducing the thermal discomfort caused by the head-to-toe temperature difference and improving the heating efficiency of the air conditioner.

[0033] A duct is connected to the air inlet of the cabinet air conditioner, allowing it to draw air from the upper part of the room. The duct wraps around and covers the air inlet of the cabinet air conditioner, extending in a cylindrical shape to the upper part of the room (190mm in diameter); the air inlet of the duct is 380mm from the ceiling. It is worth noting that the duct in this embodiment is a simplified laboratory version and not a commercial product. The following experimental data demonstrate that this simplified version can fully verify the effectiveness of the method of the present invention.

[0034] In the high-temperature hot air supply mode, indoor air entering the air conditioner is heated by the air conditioner's heating function and then blown from the air conditioner outlet to the lower part of the room where people are active. The airflow intensity and velocity of the high-temperature hot air supply are determined based on thermal comfort standards or people's thermal preferences. The indoor air entering the air conditioner can be air from the upper part of the room via a duct; it can also be air from the air inlet of a conventional cabinet air conditioner (usually the air inlet located at the bottom of the air conditioner). In this embodiment, based on the thermal preferences of the test subjects, the airflow angle of the high-temperature hot air supply is set to horizontal, and the airflow velocity is set to automatic mode. The temperature of the high-temperature hot air supply mode is set to 28°C. The indoor air entering the air conditioner can be air from the upper part of the room via a duct.

[0035] In low-temperature hot air supply mode, the air conditioner's air inlet draws air from the upper part of the room into the air conditioner via a duct. The air entering the air conditioner is hot air that has accumulated in the upper part of the room due to thermal buoyancy. In high-temperature hot air supply mode, this air is heated by the air conditioner, but in low-temperature air supply mode, it is not heated by the air conditioner and is blown from the air conditioner outlet to the lower part of the room where people are active. The air delivery angle and speed of the low-temperature hot air supply are determined based on thermal comfort standards or people's thermal preferences. In this embodiment, based on the thermal preferences of the experimental personnel, the air delivery angle of the low-temperature hot air supply is set to horizontal, and the air delivery speed is set to medium speed.

[0036] A higher airflow velocity in the low-temperature hot air supply mode allows more hot air from the upper part of the room to be delivered to the lower part of the room where people are active, but this increases the air velocity in the activity area. The maximum airflow velocity in the low-temperature hot air supply mode is determined based on a limit value for the air velocity in the activity area caused by the low-temperature hot air supply mode, which is determined based on thermal comfort standards or people's thermal preferences. In this embodiment, the experimenters set the air velocity limit in the activity area of ​​the present invention to not exceed the maximum value of the air velocity in the activity area of ​​the existing method.

[0037] The longer the low-temperature hot air supply mode operates compared to the high-temperature hot air supply mode, the higher the air conditioning energy efficiency. However, because the heat transferred from the upper part of the room is insufficient to offset the cold air entering the activity area from the outside, the temperature in the activity area decreases. The operating time of the low-temperature hot air supply mode relative to the high-temperature hot air supply mode is determined by the limit value of the air temperature in the activity area, which is determined based on thermal comfort standards or people's thermal preferences. In this embodiment, the experimenters set the ratio of low-temperature hot air supply time to high-temperature hot air supply time to 1:1, both being 15 minutes. The test of the method of this invention lasted for 90 minutes, that is, three cycles of alternating operation of low-temperature hot air supply and high-temperature hot air supply.

[0038] To demonstrate the advantages of this invention, the embodiments also tested existing methods. Existing methods utilize a cabinet air conditioner to provide heat to the room via hot air delivery, meaning the air conditioner is only in heating mode. The parameter settings for the heating mode of the cabinet air conditioner in the existing method are consistent with the parameter settings for the high-temperature hot air delivery mode of this invention. The existing method was tested for 60 minutes, with the first 30 minutes being the air conditioner startup phase and the latter 30 minutes being the stable operation phase of the existing method.

[0039] This embodiment actually measured the inlet and outlet air temperatures of the air conditioner, as well as the outlet air velocity. Simultaneously, measurements were taken at measuring lines L1-L4 (…). Figure 2 Each measuring line measures air temperature and velocity at four altitudes: 0.1m, 1.1m, 1.7m, and 2.7m. Measuring lines L1 and L3 are located in the near and far zones of the air conditioning supply jet, respectively. Measuring lines L2 and L4 are located in the near and far zones outside the air conditioning supply jet, respectively.

[0040] Using the existing method, when the air conditioner is operating stably, the thermal stratification temperature difference (i.e., the temperature difference between 2.7m and 0.1m) along the measurement line L1-L4 ranges from 11.0℃ to 13.2℃ (average 11.8℃). Figure 4 – Figure 8 This indicates that existing methods cause a significant amount of heat to accumulate in the upper part of the room, leading to heat waste. The power consumption of existing methods is 2.2kW. Figure 9 ).

[0041] Under the existing method, the head-to-toe temperature difference in the seated position (i.e., the temperature difference at 1.1m and 0.1m) and the head-to-toe temperature difference in the standing position (i.e., the temperature difference at 1.7m and 0.1m) along survey lines L1-L4 are respectively between 6.1℃–13.7℃ (average 8.6℃) and 9.0℃–18.8℃ (average 11.6℃). Figure 4 – Figure 8 The head-to-toe temperature difference limit (i.e., 3°C) stipulated by the ultra-thermal comfort standard leads to thermal discomfort.

[0042] Under the method of this invention, the thermal stratification temperature difference (i.e., the temperature difference between 2.7m and 0.1m) is reduced to 5.7℃–7.0℃ (average 6.5℃). Figure 4 – Figure 8 This indicates that the present invention effectively transfers heat from the upper part of the room to the lower part of the room where people are active, creating a thermally comfortable environment for these areas and reusing previously wasted heat. Because the present invention can efficiently utilize heat to create a thermally comfortable environment, it reduces power consumption to 1.0 kW, achieving an energy saving rate of 53.6% compared to existing methods. Figure 9 ).

[0043] Under the method of this invention, the head-to-toe temperature difference in the seated position (i.e., the temperature difference at 1.1m and 0.1m) and the head-to-toe temperature difference in the standing position (i.e., the temperature difference at 1.7m and 0.1m) of the survey lines L1-L4 are respectively between 2.1℃–5.5℃ (average 3.5℃) and 3.9℃–9.0℃ (average 5.8℃). Figure 4 – Figure 8 Compared with existing methods, this method reduces the head-to-toe temperature difference by an average of 59.0% and 50.3% in sitting and standing postures, respectively, significantly alleviating the thermal discomfort caused by excessive head-to-toe temperature differences.

[0044] In summary, existing methods for heating with cabinet air conditioners are limited by thermal buoyancy, causing heat to accumulate in the upper part of the room. This results in low energy efficiency in creating a comfortable thermal environment and excessive temperature difference between the head and feet. This invention utilizes the high-temperature hot air delivery mode of the cabinet air conditioner to provide heat to the room, and then uses the low-temperature hot air delivery mode to transfer the heat generated by the high-temperature hot air delivery mode, which accumulates in the upper part of the room due to thermal buoyancy, to the lower part of the room where people are active. This allows for the reuse of heat from the upper part of the room to create a better thermal environment in the lower part, achieving an energy saving rate of 53.6%. Furthermore, this invention reduces the head-to-foot temperature difference by 59.0% and 50.3% for sitting and standing postures, respectively, alleviating the thermal discomfort caused by excessive head-to-foot temperature differences.

Claims

1. A method for efficient heating in a cabinet-type air conditioner that alternates between high-temperature and low-temperature hot air supply, characterized in that, The cabinet air conditioner alternates between high-temperature hot air supply mode and low-temperature hot air supply mode. The high-temperature hot air supply mode is generated by the air conditioner to heat the room; the low-temperature hot air supply mode does not require air conditioning heating. The low-temperature hot air supply mode reuses the hot air that has accumulated in the upper space of the room under the high-temperature hot air supply mode to create heat in the lower space of the room where people are active, thereby reducing the temperature difference between the head and feet and improving the heating efficiency of the air conditioner. Connect an air duct to the air inlet of the cabinet air conditioner so that the cabinet air conditioner draws air from the upper part of the room; In the high-temperature hot air supply mode, the indoor air entering the air conditioner is heated by the air conditioner and then blown from the air conditioner outlet to the lower part of the room where people are active. The air supply angle and speed of the high-temperature hot air supply are determined according to thermal comfort standards or people's thermal preferences. The indoor air entering the air conditioner comes from the upper space of the room through the air duct or from the air inlet of a conventional cabinet air conditioner. In low-temperature hot air supply mode, the air conditioner intake draws air from the upper part of the room into the air conditioner. The air entering the air conditioner is hot air that has been heated by the air conditioner in high-temperature hot air supply mode due to thermal buoyancy and has accumulated in the upper part of the room. In low-temperature air supply mode, it does not need to be heated by the air conditioner and is blown from the air conditioner outlet to the lower part of the room where people are active. The air supply angle and speed of low-temperature hot air supply are determined according to thermal comfort standards or people's thermal preferences.

2. The efficient heating method for a cabinet air conditioner with alternating high-temperature and low-temperature hot air supply according to claim 1, characterized in that, The higher the air supply speed in the low-temperature hot air supply mode, the more hot air from the upper part of the room is delivered to the lower part of the room where people are active, but this increases the air velocity in the people's activity area. The maximum air supply speed in the low-temperature hot air supply mode is determined based on the limit value of the air velocity in the people's activity area caused by the low-temperature hot air supply mode. The limit value of the air velocity in the people's activity area is determined based on thermal comfort standards or people's thermal preferences.

3. The efficient heating method for a cabinet air conditioner with alternating high-temperature and low-temperature hot air supply according to claim 1, characterized in that, The longer the low-temperature hot air supply mode operates compared to the high-temperature hot air supply mode, the higher the air conditioning energy efficiency. However, because the heat transferred from the upper part of the room is insufficient to offset the cold air entering the activity area from the outside, the temperature in the activity area decreases. The operating time of the low-temperature hot air supply mode compared to the high-temperature hot air supply mode is determined by the limit value of the air temperature in the activity area, which is determined based on thermal comfort standards or people's thermal preferences.

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