Building energy-saving roof system and method with heat flow automatic regulation capability

Abstract

A building energy-saving roof system and method with the ability to automatically adjust heat flow, the system includes: a heat pipe, a radiation panel, an air duct and a fan, the radiation panel is located outdoors, radiates energy outward at a set wavelength, and has a set reflectivity; the cold end of the heat pipe is connected to the lower side of the radiation panel, and the hot end is arranged in the air duct; the air duct is arranged indoors and connected to the room; the controllable start and stop fan is used to send indoor air into the air duct. The system can automatically and efficiently conduct heat to the outside when the indoor temperature is high, and can independently export indoor heat with zero energy consumption, and can also cooperate with the circulation fan to reduce the energy consumption of conventional indoor environmental control devices.

Description

Technical Field

[0001] The present invention belongs to the technical field of building energy conservation and can be used for the construction of low-carbon energy-saving buildings. More specifically, it relates to a building energy-saving roof device and system with automatic heat flow regulation capability. Background Art

[0002] Radiative cooling technology is a new technology that uses the temperature difference between the earth's surface (~300K) and outer space (~3K) to transfer thermal radiation to achieve zero-energy cooling. In the atmospheric window band (8~13 μm), the atmosphere is highly transparent to thermal radiation, so any object with high emissivity in the atmospheric window can radiate heat to outer space. The sun's radiation to the earth is mainly concentrated in the 0.3~2.5μm band. Most thermal radiation materials absorb incident sunlight and convert it into heat, causing the object's temperature to rise. Therefore, having high reflectivity in the sunlight band and high infrared emissivity in the atmospheric window band is the key to achieving radiative cooling.

[0003] Heat pipes use the phase change process of the working medium evaporating at the hot end and condensing at the cold end (i.e., using the latent heat of evaporation and condensation of the liquid) to conduct heat quickly. Heat pipe technology is widely used in aerospace, military and other industries, especially for enhancing heat exchange. Heat pipes can transfer heat quickly and efficiently, and their thermal conductivity can be dozens or even hundreds of times that of metal copper. The common thermal conductivity coefficient of heat pipes is arrive .

[0004] In order to avoid the adverse effects of outdoor climate, existing building envelope structures follow the design concept of "thermal insulation". This type of envelope structure simply and roughly blocks the heat flow between indoor and outdoor. Although it guarantees the thermal comfort of the room to a certain extent, the indoor temperature is usually high in summer and air conditioning is still required. In addition, due to the thermal inertia of the building, overheating often occurs indoors. For example, in the evening of summer, it is often hotter indoors than outdoors. This is an inherent drawback of the traditional thermal design of the envelope structure, which leads to the need for additional air conditioning, which is one of the important reasons for the high energy consumption of buildings.

[0005] How to improve the design of building envelope structures, in summer, while isolating outdoor heat from entering the room, quickly discharge the heat inside the building, and in winter, block the indoor heat from radiating to the outside, so that the interior of the building can be maintained in a thermal comfort range throughout the year, which is of great significance for the energy-saving operation of buildings. For the optimization of thermal performance of building walls, roofs, etc., existing research mainly focuses on directly using heat pipes to quickly transfer heat from the heat source to low temperature. However, due to the small temperature difference, it is difficult to obtain a low-temperature outdoor environment in the summer when the cooling demand is high, and the building envelope containing heat pipes has limited effect. Radiant cooling technology has been proven to have a good cooling effect, but how to effectively combine it with buildings to give full play to its cooling effect on the indoor environment in summer while avoiding adverse effects in winter is still lacking.

[0006] Prior art document 1 (CN107975895B) discloses a composite energy-saving device based on radiation refrigeration and phase change energy storage and a method thereof, which belongs to the field of radiation refrigeration. Its disadvantage is that it has a single cooling function, cannot take into account the heat preservation and heat insulation effect in winter, and has a poor indoor cooling effect in summer. Radiant cooling materials with a single cooling function often cannot meet the various needs of real life, and the cost of using radiant refrigeration materials is relatively high. The existing radiant refrigeration devices used in buildings have poor compatibility with different buildings and different environments.

[0007] Prior art document 2 (CN107316914A) discloses a system for cooling concentrated photovoltaic cells by radiative heat exchange with space, and prior art document 3 (CN115279116A) discloses a heat dissipation device for a communication base station shell and a preparation method thereof. The shortcomings of the prior art represented by these two published patents are that the technical solutions are only applicable to specific scenarios and cannot be extended to a wider range of building roofs. Prior art document 2 is a device specifically developed for heat dissipation of solar concentrated photovoltaic cells based on radiative cooling technology, and prior art document 3 is specially designed for heat dissipation of communication base station shells based on natural convection heat exchange technology. Summary of the invention

[0008] In order to solve the deficiencies in the prior art, the present invention provides a building energy-saving roof device with the ability to automatically adjust heat flow. Specifically, in view of the relatively weak convective heat exchange between the heat absorption section and the heat release section of the heat pipe and the environment, and the lack of low-temperature environment, an energy-saving roof device and system with heat flow adjustment capability suitable for buildings is proposed, which is a lower-cost, more energy-saving and more practical solution.

[0009] The present invention adopts the following technical solution.

[0010] The first aspect of the present invention provides a building energy-saving roof system with the ability to automatically adjust heat flow, including: a heat pipe, a radiation panel, an air duct and a fan:

[0011] The radiation panel is located outdoors, radiates energy outward at a set wavelength, and has a set reflectivity;

[0012] The cold end of the heat pipe is connected to the lower side of the radiation plate, and the hot end is arranged in the air duct;

[0013] The air duct is arranged indoors and connected with the indoor room;

[0014] A fan with controllable start and stop is used to deliver indoor air into the air duct.

[0015] Preferably, the building energy-saving roof system packages the heat pipes, radiation panels, air ducts and fans into a whole.

[0016] Preferably, the cold end of the heat pipe is arranged outdoors, and a heat exchange fin is arranged on the surface, which is connected to the radiation plate as a whole; the connecting pipe between the hot end and the cold end is arranged in the roof structure layer of the building;

[0017] The hot end of the heat pipe is arranged indoors, and heat exchange fins are arranged on the surface and arranged in the air duct;

[0018] The heat pipe is filled with a medium.

[0019] Preferably, the heat pipe is a thermosiphon, including a medium filling and a medium discharge interface. A heat pipe without a medium is a poor conductor of heat.

[0020] Preferably, the boiling point of the medium is the same as the upper control limit of the indoor temperature. When the indoor temperature reaches the upper control limit, the medium boils and the heat pipe works; when the indoor temperature is lower than the upper control limit, the heat pipe does not work.

[0021] Preferably, the radiation plate comprises: an aluminum plate substrate and a coating, the coating comprising silicon dioxide microspheres, the coating radiating energy outward in the form of infrared electromagnetic waves with a wavelength of 8-14 microns for cooling;

[0022] The coating's sunlight reflectivity is no less than 96%

[0023] Preferably, the building energy-saving roof system further comprises: a first temperature sensor for measuring room temperature, a second temperature sensor for measuring the temperature of the radiation panel, and a control module;

[0024] The control module receives room temperature data and the temperature of the radiation panel, and controls the start and stop of the fan based on the built-in fan control logic to adjust the indoor temperature.

[0025] A second aspect of the present invention provides a building energy-saving method for controlling a building energy-saving roof system with automatic heat flow regulation capability, comprising the following steps:

[0026] Step 1, collecting the room temperature and the radiation plate temperature, when the room temperature exceeds the upper limit, determining whether the radiation plate temperature is higher than the room temperature upper limit, if it exceeds the room temperature upper limit, executing step 2, if it does not exceed the room temperature upper limit, executing step 3;

[0027] Step 2: The heat pipe does not work, and heat is not transferred between the indoor and outdoor areas through the heat pipe. The room temperature is adjusted by the conventional air conditioning refrigeration group 3, and the process returns to step 1.

[0028] Step 3: The heat pipe works. Heat is transferred between indoor and outdoor through the heat pipe. The fan cooling performance coefficient is calculated. ;

[0029] Step 4: If the fan cooling performance coefficient Higher than the cooling performance coefficient of air conditioning units , turn on the fan, otherwise, stop the fan.

[0030] Preferably, when the heat pipe is not needed to conduct heat, the heat pipe medium is evacuated, and the heat pipe becomes a poor conductor of heat and cannot transfer heat;

[0031] When the upper limit of room temperature needs to be adjusted, replace the working medium of the heat pipe with a different boiling point.

[0032] Preferably, in step 4, the fan cooling performance coefficient is calculated by the following formula: :

[0033] (1)

[0034] Where:

[0035] is the air density in ;

[0036] is the specific heat capacity of air, in ;

[0037] is the cross-sectional area of ​​the air duct, in units of ;

[0038] , They are the wind speed in the air duct when the fan is turned on and when the fan is not turned on, in m / s;

[0039] is the air temperature at the duct inlet, in K;

[0040] , are the air temperatures at the duct outlet when the fan is turned on and off, respectively, in K;

[0041] W is the power of the fan, in W.

[0042] Compared with the prior art, the beneficial effects of the present invention include at least the following: the present invention is more widely used and can be generally used on building roofs. In summer (when the indoor temperature is high), heat pipes and forced convection heat exchange are used to enhance the heat dissipation effect of the outdoor radiation refrigeration panel. In winter (when the indoor temperature is low), the heat pipes do not work and the indoor fans used to enhance convection heat exchange do not work, thereby blocking the heat loss of the building, so that the indoor temperature of the building is maintained within a specific temperature range throughout the year. Based on the working temperature of the heat pipes, precise indoor temperature control can be achieved, effectively reducing or even eliminating indoor air conditioning electricity consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0044] Figure 1 It is a heat pipe arrangement and working principle diagram provided according to an embodiment of the present invention;

[0045] Figure 2 It is a working logic diagram of a heat pipe heat dissipation circulation fan provided in accordance with an embodiment of the present invention;

[0046] Figure 3 is a schematic diagram of a building energy-saving roof device with automatic heat flow regulation capability provided in accordance with an embodiment of the present invention;

[0047] In the figure:

[0048] 1- Radiant panel;

[0049] 2-Heat pipe cooling circulation fan;

[0050] 3- Conventional air conditioning refrigeration group;

[0051] 4-heat pipe heat release end;

[0052] 5-heat absorbing end of the heat pipe;

[0053] 6-Roof structure layer;

[0054] 7- Heat exchange fins at the heat release end of the heat pipe;

[0055] 8- Heat pipe heat absorption end enhanced heat exchange fins;

[0056] 9-Indoor hot air;

[0057] 10- Cooling the air. DETAILED DESCRIPTION

[0058] In order to make the purpose, technical scheme and advantages of the present invention clearer, the technical scheme of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. The described embodiments are only embodiments of a part of the present invention, not all embodiments. Based on the spirit of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work belong to the protection scope of the present invention.

[0059] like Figure 3 As shown, Example 1 of the present invention provides a building energy-saving roof system with the ability to automatically adjust heat flow, which combines heat pipes, high-reflection panels that can radiate heat into space, and fans, including: heat pipes with specific working temperatures, radiation panels 1 with specific radiation wavelengths, enhanced heat exchange fins, fans, and control modules. Under specific conditions, the heat accumulated in the building can be quickly discharged, and the operating energy consumption is lower than that of conventional air-conditioning systems.

[0060] Preferably, the building energy-saving roof system can be processed and packaged into a module in the factory and used as a modular building roof. The heat pipe, fan, control module, heat exchange fin and radiation panel can also be installed on site according to the actual construction of the building. Different heat pipes can be selected according to the indoor temperature control requirements of different buildings.

[0061] In a preferred but non-limiting embodiment, the building is a farmhouse.

[0062] It is understandable that a general heat pipe includes: a tube shell, a liquid wick and an end cap. The inside of the heat pipe is evacuated to a negative pressure state and filled with a suitable liquid. The boiling point of this liquid can be controlled by the vacuum degree and the choice of the medium to obtain heat pipes with different starting temperatures.

[0063] like Figure 1 As shown, the heat pipe is divided into a hot end and a cold end, namely, a heat absorbing end 5 of the heat pipe and a heat releasing end 4 of the heat pipe. The heat absorbing end 5 of the heat pipe is heated by the outside, and the internal medium evaporates to form steam, which automatically rises to the cold end, condenses at the heat releasing end 4 of the heat pipe to release heat to form droplets, and automatically flows back to the hot end. The heat pipe medium automatically circulates inside the heat pipe through the evaporation-condensation process, transferring heat from the hot end to the cold end. When the temperature of the evaporation section of the heat pipe is higher than the boiling point of the liquid, the working liquid in the core evaporates due to the heat and takes away the heat. The steam flows from the central channel to the condensation section of the heat pipe, condenses into liquid, and releases latent heat at the same time. Under the action of gravity or capillary adsorption, the liquid flows back to the evaporation section. In this way, a closed cycle is completed, thereby transferring a large amount of heat from the heating section to the heat dissipation section.

[0064] Preferably, the present invention adopts a thermosiphon. When the heating section is at the bottom and the cooling section is at the top, and the heat pipe is placed vertically, the reflux of the working liquid can be satisfied by gravity, and there is no need for a capillary structure wick, and there is no porous wick. Based on the existing heat pipe, the present invention reserves a working medium filling / discharging interface for the heat pipe. When the heat pipe needs to conduct heat, the medium is filled to make the heat pipe work normally and transfer heat. When the heat pipe does not need to conduct heat, the heat pipe medium is evacuated, and the heat pipe becomes a poor conductor of heat and cannot transfer heat.

[0065] Preferably, in order to enhance heat exchange, fins for enhancing heat exchange are welded at both the heat absorbing end and the heat dissipating section of the heat pipe, i.e., the heat absorbing end of the heat pipe is enhanced with heat exchange fins 8 and the heat releasing end of the heat pipe is enhanced with heat exchange fins 7. By encapsulating a working fluid with the same boiling point as the indoor design temperature in the heat pipe, placing the heat absorbing evaporation section of the heat pipe in the indoor air duct and adding heat exchange fins on the surface of the heat pipe, placing the heat dissipating condensing section of the heat pipe outdoors and adding heat exchange fins to connect with the radiation plate as a whole, and dissipating heat by enhancing radiation and convection with the outside air, the heat pipe connection section is placed in the roof structure layer, and when the indoor temperature is higher than the allowable temperature limit, the heat pipe (passive) automatically starts to work and discharges heat to the outdoors, and when the outdoor temperature is higher than the indoor temperature or the indoor temperature does not exceed the limit, the heat pipe does not work.

[0066] Further preferably, the number of heat pipes is proportional to the area of ​​the roof structure layer 6, for example but not limited to, each square meter of the roof module contains one heat pipe, and the thermal conductivity of a single heat pipe is , the heat pipe is about 0.1m long and the cross-sectional area is 0.001 , the heat is transferred to the radiation plate through the metal fins. When the temperature difference between indoor and outdoor is 1-10℃, the heat transfer of the heat pipe is 0.1-1 Correspondingly, the radiant heat dissipation of the roof radiation panel is 0.1-0.2 The heat transfer of the outdoor heat dissipation section fins is 0.3-0.8 The heat transfer of the fins of the indoor heat pipe absorption section is 0.1-1 .

[0067] It is further preferred that the maximum allowable temperature in the building is 303.15K. When filling the heat pipe, a heat pipe with an operating temperature of about 303.15K is selected, that is, when the temperature of the heat absorbing end reaches 303.15K, the liquid in the heat absorbing section of the heat pipe begins to boil and the liquid turns into steam. When the indoor temperature is lower than 303.15K, the heat pipe does not work, and it is difficult to exchange heat between indoor and outdoor through the heat pipe, so as to avoid continuously lowering the indoor temperature of the building in winter. When the temperature of the outdoor radiation heat dissipation section is lower than 303.15K, the heat pipe starts to conduct heat, directing the indoor heat to the outdoors and lowering the indoor temperature; in the rare period of summer, when the temperature of the outdoor radiation heat dissipation section, that is, the heat release section of the heat pipe, is higher than 303.15K, the heat pipe does not work. At the same time, the outdoor heat cannot be conducted to the indoor through the heat pipe, and the heat pipe has no negative effect on the heat transfer of the building. During most of the year, the system can conduct the heat in the building to the outdoors.

[0068] The roof radiation panel is coated with a thin film material made of silicon dioxide microspheres randomly embedded in polymethylpentene on the surface of the aluminum plate, radiating energy in the form of 8-14 micron wavelength infrared electromagnetic waves to achieve a cooling effect. The reflectivity of solar energy is above 96%. This material has a maximum heat dissipation of up to 90% under direct sunlight at noon. radiative cooling power.

[0069] The earth's atmosphere has almost no resistance to the energy of the 8-14 micron wavelength infrared electromagnetic waves radiated by the radiation panel. The emitted heat is almost not consumed by the atmosphere through reflection, absorption and scattering, and can directly pass through the atmosphere and enter the outer space, transmitting energy to the extremely cold environment of outer space, thereby reducing the temperature of the radiation panel and transferring the indoor heat to the outdoors in a timely manner.

[0070] It is worth noting that in order to avoid the adverse effects of outdoor climate, buildings usually have relatively thick enclosure structures with attached insulation, which makes the thermal conductivity of the building enclosure structure extremely low and thermally inert. The device represented by prior art document 1 is applied to the roof or exterior wall, and the cold stored at night cannot be effectively transferred to the room during the day, thereby failing to effectively reduce the indoor temperature. If a thin enclosure structure is used, the heat gain of the building through the enclosure structure will increase during the hot day, which is not conducive to indoor cooling. At the same time, the device is in cooling mode all year round, which is obviously not conducive to maintaining indoor temperature in winter.

[0071] As one of the outstanding substantial features of the present invention, the present invention combines the heat pipe technology with the radiation cooling technology, based on the working characteristics of the heat pipe, that is, the efficient unidirectional thermal conductivity at a specific temperature, to enhance the radiation cooling effect in summer (when the indoor temperature exceeds the phase change temperature of the medium in the heat pipe, and the temperature of the radiation heat sink is lower than the phase change temperature of the medium, the heat pipe works, and the indoor heat is quickly transferred to the radiation cooling device through the heat pipe and dissipated), and at the same time can cut off the radiation cooling effect in winter (when the indoor temperature is lower than the phase change temperature of the medium in the heat pipe, the heat pipe does not work, and the indoor heat cannot be transferred to the radiation cooling device through the heat pipe).

[0072] Therefore, the significant improvements brought by the present invention to the prior art include at least: it can promote the maintenance of a specific indoor temperature regardless of summer or winter, effectively realize precise indoor temperature control, and effectively reduce or even eliminate indoor air conditioning electricity consumption.

[0073] A heat pipe heat dissipation circulation fan 2 is arranged in the air duct where the indoor heat pipe heat dissipation section is located. Indoor hot air 9 enters from the air duct inlet, and heat exchange is enhanced when the heat transfer amount is large. After cooling, air 10 flows out from the air duct outlet. At the same time, the start and stop of the fan is determined according to the heat transfer amount of the heat pipe. When the heat transfer amount increased by the fan is insufficient, the fan stops working. The fan starts working only when the heat transfer "gain" generated by the fan operation, that is, the fan cooling efficiency exceeds that of the air conditioner. The system can automatically and efficiently conduct heat to the outside when the indoor temperature is high. It can independently export indoor heat with zero energy consumption, and can also cooperate with the circulation fan to reduce the energy consumption of conventional indoor environmental control devices.

[0074] like Figure 2 As shown in the figure, after the heat pipe is filled with working medium according to the indoor temperature control requirements of the building, it can automatically start passive heat transfer according to the temperature difference between indoor and outdoor, and only transfer heat in one direction, that is, heat will only be transferred from indoor to outdoor, and not from outdoor to indoor. When heat is transferred from indoor to outdoor, it can be enhanced by indoor circulation fans, or it can be naturally exchanged when the fans are not started, so as to minimize energy consumption.

[0075] The judgment logic for starting the circulating fan in the heat pipe heat dissipation section of the building is as follows:

[0076] Calculating the coefficient of performance of circulating fan cooling , expressed as follows:

[0077] (1)

[0078] Where:

[0079] is the air density in ;

[0080] is the specific heat capacity of air, in ;

[0081] is the cross-sectional area of ​​the air duct, in units of ;

[0082] , They are the wind speed in the air duct when the fan is turned on and when the fan is not turned on, in m / s;

[0083] is the air temperature at the duct inlet, in K;

[0084] , are the air temperatures at the duct outlet when the fan is turned on and off, respectively, in K;

[0085] W is the power of the fan, in W.

[0086] Get the cooling coefficient of the air conditioning system selected for the building ,when When the fan is turned on to enhance the heat exchange on the indoor side, otherwise the fan is not turned on, and the heat is only exchanged through the heat conduction capacity of the heat pipe itself, transferring part of the indoor heat to the outdoors.

[0087] Compared with the devices represented by prior art documents 2 and 3, as another outstanding substantial feature of the present invention and a significant improvement over the prior art, the present invention ① is suitable for a variety of working conditions through the combination of heat pipe technology and radiation cooling technology. It enhances the radiation cooling effect in summer when the building needs to dissipate heat to the outdoors in summer, and effectively blocks the indoor heat from dissipating to the outdoors when the building needs insulation in winter; ② utilizes forced convection between the heat pipe and the indoor room to significantly enhance the radiation cooling effect, thereby reducing the amount of radiation cooling materials used and the cost of using radiation cooling materials; ③ the device has a relatively simple structure and strong compatibility, and is suitable for various building roofs in multiple climate zones such as hot summer and cold winter. At the same time, by replacing different working fluids in the heat pipe, the working temperature of the heat pipe is changed, thereby changing the upper limit of indoor temperature control and achieving precise temperature control.

[0088] The present invention has a wider scope of application. In summer (when the indoor temperature is high), heat pipes and forced convection heat exchange are used to enhance the heat dissipation effect of the outdoor radiation refrigeration panel. In winter (when the indoor temperature is low), the heat pipes do not work and the indoor fans used to enhance convection heat exchange do not work, thereby blocking the heat loss of the building, so that the indoor temperature of the building is maintained within a specific temperature range throughout the year, and precise indoor temperature control can be achieved, effectively reducing or even eliminating the electricity consumption of indoor air conditioning.

[0089] A second aspect of the present invention provides a building energy-saving method for controlling a building energy-saving roof system with automatic heat flow regulation capability as described in Example 1, comprising the following steps:

[0090] Step 1, collecting the room temperature and the radiation plate temperature, when the room temperature exceeds the upper limit, determining whether the radiation plate temperature is higher than the room temperature upper limit, if it exceeds the room temperature upper limit, executing step 2, if it does not exceed the room temperature upper limit, executing step 3;

[0091] Step 2: The heat pipe does not work, and heat is not transferred between indoor and outdoor through the heat pipe. The room temperature is adjusted by the air conditioning unit 3, and the process returns to step 1.

[0092] Step 3: The heat pipe works. Heat is transferred between indoor and outdoor through the heat pipe. The fan cooling performance coefficient is calculated. ;

[0093] Step 4: If the fan cooling performance coefficient Higher than the cooling performance coefficient of air conditioning unit 3 , turn on the fan, otherwise, stop the fan.

[0094] Preferably, when the heat pipe is not needed to conduct heat, the heat pipe medium is evacuated, and the heat pipe becomes a poor conductor of heat and cannot transfer heat;

[0095] When the upper limit of room temperature needs to be adjusted, replace the working medium of the heat pipe with a different boiling point.

[0096] Preferably, in step 4, the fan cooling performance coefficient is calculated by the following formula: :

[0097] (1)

[0098] Where:

[0099] is the air density in ;

[0100] is the specific heat capacity of air, in ;

[0101] is the cross-sectional area of ​​the air duct, in units of ;

[0102] , They are the wind speed in the air duct when the fan is turned on and when the fan is not turned on, in m / s;

[0103] is the air temperature at the duct inlet, in K;

[0104] , are the air temperatures at the duct outlet when the fan is turned on and off, respectively, in K;

[0105] W is the power of the fan, in W.

[0106] Embodiment 3 of the present invention provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the computer program implements a building energy-saving method according to Embodiment 2 when loaded into the processor.

[0107] Embodiment 4 of the present invention provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and is characterized in that when the computer program is executed by a processor, a building energy-saving method according to Embodiment 2 is implemented.

[0108] The present disclosure may be a system, a method and / or a computer program product. The computer program product may include a computer-readable storage medium carrying computer-readable program instructions for causing a processor to implement various aspects of the present disclosure.

[0109] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents, and any modifications or equivalent replacements that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A building energy-saving roof system with automatic heat flow regulation capability, comprising: The heat pipe, radiation plate, air duct and fan are characterized by: The heat pipe, radiation panel, air duct and fan are packaged into a whole; The radiation panel is located outdoors, radiates energy outward at a set wavelength, and has a set reflectivity; The cold end of the heat pipe is set outdoors, with heat exchange fins on the surface, connected to the radiation plate as a whole; the connecting pipe between the hot end and the cold end is set in the roof structure layer of the building; The hot end of the heat pipe is arranged indoors, and heat exchange fins are arranged on the surface and arranged in the air duct; The cold end of the heat pipe is connected to the lower side of the radiation plate, and the hot end is set in the air duct; the heat pipe passively starts heat transfer according to the temperature difference between indoor and outdoor; the heat pipe is filled with a medium, and the boiling point of the medium is the same as the upper limit of the indoor temperature control. When the indoor temperature reaches the upper limit, the medium boils and the heat pipe works; when the indoor temperature is lower than the upper limit, the heat pipe does not work; By replacing different working media in the heat pipe, the working temperature of the heat pipe can be changed, thereby changing the upper limit of indoor temperature control; the heat pipe is a thermal siphon, including medium filling and discharge interfaces, and the heat pipe without medium is a poor conductor of heat; when the heat pipe does not need to conduct heat, the heat pipe medium is evacuated, and the heat pipe becomes a poor conductor of heat and cannot transfer heat; when the upper limit of room temperature needs to be adjusted, the working medium with different boiling points of the heat pipe is replaced; The air duct is arranged indoors and connected with the indoor room; A fan with controllable start and stop is used to deliver indoor air into the air duct.

2. The building energy-saving roof system with automatic heat flow regulation capability according to claim 1 is characterized in that: The radiation panel includes: an aluminum plate substrate and a coating, the coating includes silicon dioxide microspheres, and the coating radiates energy outward in the form of 8-14 micron wavelength infrared electromagnetic waves for cooling; The coating's sunlight reflectivity is no less than 96%.

3. A building energy-saving roof system with automatic heat flow regulation capability according to claim 1 or 2, characterized in that: The building energy-saving roof system also includes: a first temperature sensor for measuring room temperature, a second temperature sensor for measuring the temperature of the radiation panel, and a control module; The control module receives room temperature data and the temperature of the radiation panel, and controls the start and stop of the fan based on the built-in fan control logic to adjust the indoor temperature.

4. A building energy-saving method with automatic heat flow regulation capability, used to control a building energy-saving roof system with automatic heat flow regulation capability according to any one of claims 1 to 3, characterized in that: The following steps are involved: Step 1, collecting the room temperature and the radiation plate temperature, when the room temperature exceeds the upper limit, determining whether the radiation plate temperature is higher than the room temperature upper limit, if it exceeds the room temperature upper limit, executing step 2, if it does not exceed the room temperature upper limit, executing step 3; Step 2: The heat pipe does not work, and heat is not transferred between indoor and outdoor through the heat pipe. The room temperature is adjusted by the air conditioning unit, and the process returns to step 1. Step 3: The heat pipe works. Heat is transferred between indoor and outdoor through the heat pipe. The fan cooling performance coefficient COP is calculated. fan ; Step 4: If the fan cooling performance coefficient COP fan Higher than the COP of air conditioning unit AC , turn on the fan, otherwise, stop the fan.

5. A control method for a building energy-saving roof system according to claim 4, characterized in that: In step 4, the fan cooling performance coefficient COP is calculated using the following formula: fan : Where: ρ is the air density, in kg / m 3 ; c is the specific heat capacity of air, in ; S is the cross-sectional area of ​​the air duct, in m 2 ; v fan , v0 are the wind speeds in the air duct when the fan is turned on and off, respectively, in m / s; T in,0 is the air temperature at the duct inlet, in K; T out,fan , T out,0 are the air temperatures at the duct outlet when the fan is turned on and off, respectively, in K; W is the power of the fan, in W.

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