Sunshade System Capable of Independently Adjusting Thermal Insulation Performance and Sunshade Performance and Control Method Therefor

Description

FIELD OF THE DISCLOSURE

The present disclosure relates to the technical field of sunshade systems, and specifically, to a sunshade system with independently adjustable thermal insulation and shading performance as well as a control method therefor.

BACKGROUND OF THE DISCLOSURE

Studies have shown that thermal loss through external windows accounts for 40% to 50% of the total thermal loss of a building envelope, making them the weakest component in overall heat transfer of buildings. In summer, solar radiation passes through the external windows into a room, raising the indoor temperature, which leads to a deterioration of thermal environment and an increase in air conditioning energy consumption.

At present, energy-saving glazing such as Low-E glass is widely used. Although it helps reduce air conditioning energy consumption in summer, such glazing lacks the ability to dynamically adjust its thermal insulation and shading performance. As a result, it hinders indoor passive heating and natural lighting effects in winter.

SUMMARY OF THE DISCLOSURE

An objective of the present disclosure is to address the above shortcomings in the prior art by providing a control method for a sunshade system with independently adjustable thermal insulation and shading performance. This method enables the dynamic regulation of the optical and thermal properties of external windows, thereby improving the indoor thermal environment and day lighting effect, while reducing energy consumption.

Meanwhile, another objective of the present disclosure is to provide a sunshade system with independently adjustable thermal insulation and shading performance.

The objectives of the present disclosure are achieved through the following technical solutions. The control method for the sunshade system with independently adjustable thermal insulation and shading performance includes the following steps:

• • S1, a central processing unit (CPU) determines the operating duration based on a timer, obtains the current system time from a clock module, and compares it with a preset working time;
  • S2, if the operating time of the system is within the working time, the CPU performs the following operations: it receives signals from a solar radiation sensor and a temperature sensor, extracts geometric parameters of an external window according to measured values from the solar radiation sensor and the temperature sensor, invokes a sunshade area ratio prediction model to calculate a target roll film unfolding degree (H₁) for the corresponding time, and adjusts the actual roll film unfolding degree according to the target roll film unfolding degree (H₁);
  • S3, if the operating time of the system is not within the working time, the CPU determines whether the operating time is within the heating season:
  • if the operating time is within the heating season, thermal insulation of the building at night is required, and the CPU outputs a signal to the motor shaft to fully lower a roll film, thereby forming a stable adjustable air layer between the roll film and glass to enhance thermal resistance for thermal insulation;
  • if the operating time is not within the heating season, heat dissipation of the building at night is required, and the CPU outputs a signal to the motor shaft to control the roll film to fully roll up, thereby reducing thermal resistance for heat dissipation; and
  • S4, the timer repeats steps S1 to S3 at preset intervals.

A process for constructing the sunshade area ratio prediction model is as follows:

• • A1, establishing a typical building model corresponding to each thermal zone in energy consumption simulation software, and inputting relevant meteorological data;
  • A2, configuring the sunshade system with independently adjustable thermal insulation and shading performance for external windows and curtain walls of the typical building model, generating N sunshade area ratios (SR) by varying parameters of the sunshade system, and performing batch energy consumption simulations on N working conditions;
  • A3, automatically acquiring, via a scripting tool, year-round hourly building energy consumption (E), indoor daylight glare index (DGI) and outdoor environmental parameters, which are generated after simulations of the N working conditions, and screening optimal hourly SR values according to evaluation indexes that DGI is less than 19 and E is the minimum; and
  • A4, for each thermal zone, based on 8,760 sets of data screened, establishing a mathematical relationship between SR and outdoor air temperature (T_a) by nonlinear regression, to obtain sunshade area ratio prediction models for different thermal zones.

Preferably, the outdoor air synthetic temperature (T_sa) is expressed as a function of outdoor solar radiation (I) and the outdoor air temperature (T_a), as follows:

T sa = T a + ρ s ⁢ I α e ,

• • where ρ_s is the absorption coefficient of the outer surface of the building envelope to solar radiant heat, and α_e is the overall heat transfer coefficient of the outer surface of the building envelope, in W/(m²·K).

Preferably, the sunshade area ratio prediction model takes T_sa as the independent variable and it has different expressions in different thermal zones.

In the mild zone, the expression is:

SR = ( 0 . 1 × T sa 2 - 1 . 6 ⁢ 1 × T sa - 0 . 4 ⁢ 2 ) × 1 ⁢ 0 - 2

In the hot summer and warm winter zone, the expression is:

S ⁢ R ≥ 70 ⁢ % ⁢ ( T sa ≥ 34 ⁢ °C . )

In the hot summer and cold winter zone, the expression is:

S ⁢ R = ( 0 . 7 ⁢ 4 × T s ⁢ a 2 - 6 . 7 ⁢ 1 × T s ⁢ a + 3 . 3 ⁢ 3 ) × 1 ⁢ 0 - 3

In the cold zone, when the sunshade system is positioned in the east, south, or west, the expression is:

ln ⁢ S ⁢ R = - 2 . 6 ⁢ 7 + 0 . 0 ⁢ 9 × T s ⁢ a - 7 . 2 × 1 ⁢ 0 - 4 × T s ⁢ a 2

In the cold zone, when the sunshade system is positioned in the north, the expression is:

S ⁢ R = ⁢ { 100 ⁢ % ⁢ ( T sa ≤ - 3 ⁢ ° ⁢ C . ) 0 ⁢ % ⁢ ( - 3 ⁢ ° ⁢ C . < T sa ≤ 0 ⁢ ° ⁢ C . ) .

Preferably, in step S2, the CPU adjusts the actual roll film unfolding degree according to the target roll film unfolding degree (H₁) includes the following process:

A displacement sensor in the system detects the actual roll film unfolding degree (H₂), and transmits the signal to the CPU, which calculates the roll film unfolding degree deviation ΔH=H₂−H₁;

• • if ΔH>0, the CPU outputs a signal to a motor to control the roll film to roll up and the roll film unfolding degree is ΔH;
  • if ΔH=0, the roll film unfolding degree at this moment meets a requirement, and no action is required; and
  • if ΔH<0, the CPU outputs a signal to the motor to lower the roll film and the roll film unfolding degree is −ΔH.

The sunshade system with independently adjustable thermal insulation and shading performance, which implements the control method, includes a glazing system, a window frame, a sunshade mechanism, and a monitoring mechanism. The glass system is mounted on the window frame; the sunshade mechanism includes a motor, a roll film, guide rails, a heavy lower beam, and a bottom seal; the motor is mounted above the glazing system through a motor buckle cover; the roll film is connected with the motor; the lower end of the roll film is connected with the heavy lower beam; the guide rails are arranged on two sides of the glazing system; two ends of the heavy lower beam are respectively connected with the corresponding guide rails; one end of the bottom seal is connected with the lower end of the roll film; the other end of the bottom seal is connected with the surface of the glazing system in a sliding manner; two ends of the glazing system are provided with edge shading grooves; and the edge shading grooves, the glazing system, the roll film, and the bottom seal form an adjustable air layer.

Preferably, the monitoring mechanism includes a solar radiation sensor, an outdoor air temperature sensor, the displacement sensor, and the CPU; the solar radiation sensor and the outdoor air temperature sensor are both mounted outside the glazing system; the displacement sensor is mounted on the heavy lower beam; and the solar radiation sensor, the outdoor air temperature sensor, the displacement sensor, and the motor are all connected with the CPU.

Preferably, the roll film performs spectrally matched reflection of incident solar radiation, and has the transmittance of more than or equal to 70% in a wavelength range of 380-780 nm.

Preferably, the glazing system includes first glass, second glass, and a high transparent film; the first glass and the second glass form a sealed air layer; and the high transparent film is arranged in the sealed air layer to divide the sealed air layer into two independent sealed air layers.

Preferably, the sealed air layer is filled with inert gas or subjected to vacuum treatment.

Preferably, the first glass and the second glass are both ultra-white glass.

Compared with the prior art, the present disclosure has the following advantages.

• • 1. The sunshade system with independently adjustable thermal insulation and shading performance of the present disclosure enables the dynamic regulation of the optical and thermal properties of external windows, thereby improving the indoor year-round thermal environment and day lighting effect, while reducing the air conditioning and heating energy consumption of the building.
  • 2. The control method of the present disclosure constructs the sunshade area ratio prediction models and outdoor meteorological conditions by taking the minimum energy consumption of the building and daylight glare as indexes, can improve indoor thermal environment and light environment to the greatest extent, and ensures the minimum energy consumption of the building.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic structural diagram of a sunshade system with independently adjustable thermal insulation and shading performance of the present disclosure.

FIG. 2 is a side view of a sunshade system with independently adjustable thermal insulation and shading performance of the present disclosure.

FIG. 3 is a schematic diagram of a glazing system of the present disclosure.

FIG. 4 is a diagram of results of an indoor thermal environment test for a sunshade system with independently adjustable thermal insulation and shading performance of the present disclosure.

FIG. 5 is a logic block diagram of a control method of the present disclosure.

FIG. 6 is an energy-saving effect diagram of application of a control method of the present disclosure.

In figures, 1: glazing system; 2: window frame; 3: sunshade mechanism; 4: motor; 5: roll film; 6: guide rail; 7: heavy lower beam; 8: bottom seal; 9: motor buckle cover; 10: edge shading groove; 11: adjustable air layer; 12: first glass; 13: second glass; 14: high transparent film; and 15: sealed air layer.

DETAILED DESCRIPTION OF THE EMBODIMENTS

The present disclosure is further described below with reference to the accompanying drawings and embodiments.

As shown in FIG. 1 to FIG. 3, a sunshade system with independently adjustable thermal insulation and shading performance, which implements a control method, includes a glazing system, a window frame, a sunshade mechanism, and a monitoring mechanism. The glazing system is mounted on the window frame. The sunshade mechanism includes a motor, a roll film, guide rails, a heavy lower beam, and a bottom seal; the motor is mounted above the glazing system through a motor buckle cover; the roll film is connected with the motor; the lower end of the roll film is connected with the heavy lower beam; the guide rails are arranged on two sides of the glazing system; two ends of the heavy lower beam are respectively connected with the corresponding guide rails; one end of the bottom seal is connected with the lower end of the roll film; the other end of the bottom seal is connected with the surface of the glazing system in a sliding manner; two ends of the glazing system are provided with edge shading grooves; and the edge shading grooves, the glazing system, the roll film, and the bottom seal form an adjustable air layer. The monitoring mechanism includes a solar radiation sensor, an outdoor air temperature sensor, a displacement sensor, and a central processing unit (CPU); the solar radiation sensor and the outdoor air temperature sensor are both mounted outside the glazing system; the displacement sensor is mounted on the heavy lower beam; and the solar radiation sensor, the outdoor air temperature sensor, the displacement sensor, and the motor are all connected with the CPU.

Specifically, the solar radiation sensor and the outdoor air temperature sensor in the monitoring mechanism collect outdoor solar radiation data and air temperature data in real time, and transmit the data to the CPU; and on the basis of a sunshade area ratio prediction model and according to measured values from the solar radiation sensor and the temperature sensor, the CPU extracts geometric parameters of an external window to determine a target roll film unfolding degree, then compares the target roll film unfolding degree with an actual unfolding degree detected by the displacement sensor, and finally sends an instruction to the motor to adjust the roll film up or down until the actual unfolding degree is consistent with the target unfolding degree.

To ensure the operational reliability of the glazing system, the window frame in this embodiment is made of high performance profiles (such as glass fiber reinforced polyester profiles or broken bridge aluminum alloy profiles), that is, thermal performance of the window frame is made to be matched with that of the glazing system, to avoid a negative effect of a thermal bridge between the window frame and the glazing system on performance of the entire window.

The roll film performs spectrally matched reflection of incident solar radiation, and has the transmittance of more than or equal to 70% in a wavelength range of 380-780 nm. The roll film adopting this setting has the following advantages: 1, through spectrally matched reflection of the incident solar radiation, solar radiant heat entering the interior of a building is reduced; moreover, the roll film absorbs little solar radiant heat and heat entering the interior of the building through secondary heat transfer is also minimized; 2, the transmittance of more than or equal to 70% near a wavelength of 555 nm is helpful for introducing visible light to the interior of the building, and fully utilizing natural lighting, thereby reducing lighting energy consumption; and 3, compared with a traditional curtain, the roll film is more light and convenient, lower in cost, stronger in beauty, and higher in overall thermal performance.

The roll film in this embodiment is a low radiant reflectance roll film (such as a Galy series silver-plated film), and covers partial or all glazing system in summer, to reduce the solar heat gain coefficient (SHGC) of the entire window and reduce the solar radiant heat entering the interior of the building. In addition, the adjustable air layer formed between the low radiation roll film and the glazing system is utilized to further improve overall thermal insulation, so as to meet a demand in winter.

In the sunshade system with independently adjustable thermal insulation and shading performance, the glazing system is made to achieve a thermal insulation function only, rather than thermal insulation and shading functions, to the greatest extent; and the shading function is achieved by the sunshade mechanism, thereby achieving independent adjustment of thermal insulation and shading performance, meeting demands of the building, and reducing manufacturing costs.

The glazing system includes first glass, second glass, and a high transparent film; the first glass and the second glass form a sealed air layer; and the high transparent film is arranged in the sealed air layer to divide the sealed air layer into two independent sealed air layers. The first glass and the second glass are both ultra-white glass, to ensure that the glazing system has high transmittance and meets requirements for indoor day lighting on cloudy days and passive heating through solar radiation in winter. Meanwhile, the high transparent film is utilized to divide the sealed air layer into a multi-cavity structure, to reduce the overall heat transfer coefficient, thereby achieving a thermal insulation effect. To further improve the thermal insulation effect, the sealed air layer is filled with inert gas. Meanwhile, the sealed air layer may also be in a vacuum state to achieve an effect of increasing the thermal resistance of the glazing system. To reduce design cost, the ultra-white glass and the high transparent film in this embodiment may be commercially available.

Further, the glazing system is configured to be 6+12 A+6 mm, namely, 6 mm thick glass+12 mm thick sealed air layer+6 mm thick glass, so the light thermal performance adjustment range of the entire window is K=1.0-2.5 W/(m²·K), SHGC=0.15-0.70, and τ_vis=20%-75%, which may adapt to changes of demands of an indoor person.

The sunshade system with independently adjustable thermal insulation and shading performance in this embodiment was subjected to a field test in Guangzhou in summer, and test results are shown in FIG. 4. From FIG. 4, it may be known that a daytime indoor air temperature may be averagely reduced by 4.2° C. after the sunshade system with independently adjustable thermal insulation and shading performance in this embodiment is used. This indicates that the sunshade system with independently adjustable thermal insulation and shading performance has good shading performance and thermal insulation while ensuring indoor comfort.

As shown in FIG. 5, the control method for the sunshade system with independently adjustable thermal insulation and shading performance based on this embodiment includes the following steps:

• • S1, the CPU determines the operating duration based on a timer, obtains the current system time from a clock module, and compares it with a preset working time (the preset working time is 08:00 to 18:00);
  • S2, if the operating time of the system is within the working time, the CPU performs the following operations: it receives signals from the solar radiation sensor and the temperature sensor, extracts geometric parameters of the external window according to measured values from the solar radiation sensor and the temperature sensor, invokes the sunshade area ratio prediction model to calculate a target roll film unfolding degree (H₁) for the corresponding time, and adjusts the actual roll film unfolding degree according to the target roll film unfolding degree (H₁);

In step S2, the CPU adjusts the actual roll film unfolding degree according to the target roll film unfolding degree (H₁) includes the following process:

• • the displacement sensor in the system detects the actual roll film unfolding degree (H₂), and transmits the signal to the CPU, which calculates the roll film unfolding degree deviation ΔH=H₂−H₁;
  • if ΔH>0, the CPU outputs a signal to the motor to control the roll film to roll up and the roll film unfolding degree is ΔH;
  • if ΔH=0, the roll film unfolding degree at this moment meets a requirement, and no action is required;
  • if ΔH<0, the CPU outputs a signal to the motor to lower the roll film and the roll film unfolding degree is −ΔH;
  • S3, if the operating time of the system is not within the working time, the CPU determines whether the operating time is within the heating season:
  • if the operating time is within the heating season, thermal insulation of the building at night is required, and the CPU outputs a signal to the motor shaft to fully lower a roll film, thereby forming a stable adjustable air layer between the roll film and glass to enhance thermal resistance for thermal insulation;
  • if the operating time is not within the heating season, heat dissipation of the building at night is required, and the CPU outputs a signal to the motor shaft to control the roll film to fully roll up, thereby reducing thermal resistance for heat dissipation; and
  • S4, the timer repeats steps S1 to S3 at preset intervals.

A process for constructing the sunshade area ratio prediction model is as follows:

• • A1, establishing a typical building model corresponding to each thermal zone in energy consumption simulation software, and inputting relevant meteorological data;
  • A2, configuring the sunshade system with independently adjustable thermal insulation and shading performance for external windows and curtain walls of the typical building model, generating N sunshade area ratios (SR) by varying parameters of the sunshade system, and performing batch energy consumption simulations on N working conditions;
  • A3, automatically acquiring, via a scripting tool, year-round (i.e. 365×24 hours) hourly building energy consumption (E), indoor daylight glare index (DGI), and outdoor environmental parameters, which are generated after simulations of the N working conditions, and screening optimal hourly SR values according to evaluation indexes that DGI is less than 19 and E is the minimum; and
  • A4, for each thermal zone, based on 8,760 sets of data screened, establishing a mathematical relationship between SR and outdoor air temperature (T_a) by nonlinear regression, to obtain sunshade area ratio prediction models for different thermal zones.

Outdoor air synthetic temperature (T_sa) is expressed as a function of outdoor solar radiation (I) and the outdoor air temperature (T_a), as follows:

T s ⁢ a = T a + ρ s ⁢ I α e ,

• • where ρ_s is the absorption coefficient of the outer surface of the building envelope to solar radiant heat, and α_e is the overall heat transfer coefficient of the outer surface of the building envelope, in W/(m2·K).

The sunshade area ratio prediction model takes T_sa as the independent variable and it has different expressions in different thermal zones.

In the mild zone, the expression is:

S ⁢ R = ( 0 . 1 × T s ⁢ a 2 - 1 . 6 ⁢ 1 × T s ⁢ a - 0 . 4 ⁢ 2 ) × 1 ⁢ 0 - 2

In the hot summer and warm winter zone, the expression is:

S ⁢ R ≥ 70 ⁢ % ⁢ ( T s ⁢ a ≥ 34 ⁢ ° ⁢ C . )

In the hot summer and cold winter zone, the expression is:

S ⁢ R = ( 0 . 7 ⁢ 4 × T s ⁢ a 2 - 6 . 7 ⁢ 1 × T s ⁢ a + 3 . 3 ⁢ 3 ) × 1 ⁢ 0 - 3

In the cold zone, when the sunshade system is positioned in the east, south, or west, the expression is:

ln ⁢ SR = - 2 . 6 ⁢ 7 + 0 . 0 ⁢ 9 × T s ⁢ a - 7 . 2 × 1 ⁢ 0 - 4 × T s ⁢ a 2

In the cold zone, when the sunshade system is positioned in the north, the expression is:

S ⁢ R = ⁢ { 100 ⁢ % ⁢ ( T sa ≤ - 3 ⁢ ° ⁢ C . ) 0 ⁢ % ⁢ ( - 3 ⁢ ° ⁢ C . < T sa ≤ 0 ⁢ ° ⁢ C . ) .

By taking a large-scale public building in Guangzhou as an example, the above dynamic control is achieved in the energy consumption simulation software, and a result shows that compared with an existing Low-E glass external window (or curtain), the sunshade system with independently adjustable thermal insulation and shading performance reduces the year-round energy consumption of the building by 11.4%, as shown in FIG. 6 below.

The above embodiments are merely preferred implementations of the present disclosure, but are not intended to limit the present disclosure. Any other changes or equivalent replacements made without departing from the technical solutions of the present disclosure shall fall within the scope of protection of the present disclosure.