Active enclosure and temperature control system thereof

Abstract

The application discloses an active enclosure and a temperature control system thereof. A double-layer sealed cavity is arranged on the surface of the enclosure of a target space, and the temperature of the cavity is adjusted by carbon dioxide working medium. The cavity adopts directional circulation of inner air supply and outer air return to make the inner surface temperature uniform. A lightweight panel realizes flexible assembly without drilling through pre-embedded connecting pieces. The compression work is provided by a turbine-compressor coaxial unit in a local energy station, and does not rely on grid power for driving. A control platform adopts weak signal power supply. The system adaptively anchors the inner surface temperature according to the inner and outer temperatures, and controls the temperature difference in different zones within ±1℃. The system has the synergistic benefits of controllable thermal boundary, off-grid operation and seismic safety, and is suitable for the enclosure of various civil buildings, public buildings and factory buildings, and is also suitable for the shell of refrigeration equipment such as refrigerators, cold chain boxes and ship refrigerated cabins.

Description

Technical Field

[0001] This invention relates to the fields of active building envelope, building energy conservation, heating, ventilation and air conditioning and cold chain temperature control systems, and specifically to an active building envelope temperature control system based on a closed-loop carbon dioxide cycle. Background Technology

[0002] The building envelope is the physical interface between a building and its external environment, and its thermal performance directly affects building energy consumption and indoor thermal comfort. For a long time, the design of building envelopes has followed a passive resistance approach—mitigating heat transfer by increasing insulation thickness, improving airtightness, and using high-performance doors and windows. However, its performance is fixed and cannot actively regulate the internal surface temperature according to changes in outdoor climate conditions. This approach has the following inherent limitations:

[0003] (i) The temperature of the inner surface of the building envelope fluctuates passively with the outdoor climate, reaching over 40°C in summer and only 5-10°C in winter, resulting in a strong radiation effect.

[0004] (ii) The problem of thermal bridging has not been eradicated for a long time. Concrete beams, columns and other structural components penetrate the insulation layer, forming shortcuts for heat leakage.

[0005] (iii) Existing active temperature control equipment relies on mains power to drive the compressor and fan, and loses its function when the mains power is interrupted. Existing CO2 heat pumps or refrigeration units generally rely on external cold sources (air cooling or water cooling) for high-pressure side cooling. These heat sources have a high temperature grade but are not utilized, and the condensation heat is directly discharged into the environment, resulting in a waste of heat grade.

[0006] (iv) Traditional brick and stone infill walls are prone to cracking, outward displacement, or even complete collapse during earthquakes due to the sudden increase in stiffness and the incoordination with the frame deformation.

[0007] (v) Traditional building envelopes have high thermal inertia, making efficient intermittent operation impossible. Heavy materials have strong heat storage capacity, requiring reheating or cooling of the entire building envelope each time it is started or stopped, resulting in high energy consumption and slow response. Current heating systems are forced to operate continuously for 24 hours; office buildings attempt to utilize the building's stored cold by shutting down their systems before closing time, but the release of cold energy is uncontrollable, and restarting the next day is slow. Differences in air conditioning settings between adjacent rooms in residential buildings lead to heat transfer between units, further exacerbating energy consumption.

[0008] In addition, refrigeration equipment such as refrigerators and freezers also have similar problems: the condenser dissipates heat into the room, increasing the air conditioning load; the compressor relies on mains power; and polyurethane foam insulation is passive and cannot actively regulate the internal wall temperature. Cold chain logistics vehicle bodies and ship refrigerated compartments also suffer from uneven temperature distribution, large fluctuations, and high energy consumption.

[0009] To address the aforementioned limitations, this invention proposes an active enclosure structure solution. Summary of the Invention

[0010] 3.1 Purpose of the Invention

[0011] This invention aims to provide an active building envelope and its temperature control system to solve problems such as the inability of passive building envelopes to actively adjust, absolute dependence on electricity, inability to eliminate thermal bridging, and the susceptibility of traditional infill walls to collapse during earthquakes. The core concept is to create a double-layered sealed cavity on the surface of the building envelope in the target space, driven by a closed-loop circulation system using carbon dioxide as the working fluid. The compression work of this circulation is coaxially provided by the mechanical work output from a turbine-compressor coaxial unit in a local energy station, eliminating reliance on grid power to drive the compressor. This dynamically anchors the temperature of the inner surface of the building envelope to the optimal target according to operating conditions. Simultaneously, lightweight panels and flexible connections enable coordinated earthquake deformation with the main structure.

[0012] This invention structurally avoids the energy loss caused by electricity, as a high-grade energy form, driving a low-grade thermal process, thus achieving a reasonable match between energy grade demand and supply.

[0013] 3.2 Technical Solution

[0014] The closed-loop carbon dioxide cycle process of this invention is as follows:

[0015] Main operating circuit: The high-temperature and high-pressure (7.4~7.5MPa, 200~300℃) working fluid output from the local energy station flows sequentially through the heating circuit, regenerator, high-pressure carbon storage tank, high-pressure energy supply pipeline, cooling circuit, low-pressure return gas pipeline, deep drying filter, low-pressure carbon storage tank, regenerator, turbine-compressor coaxial unit, and carbon dioxide heating device, before returning to the local energy station.

[0016] The local energy station includes a multi-stage compression unit consisting of a turbine-compressor coaxial unit. This unit compresses the low-pressure working fluid (3.6~3.98MPa) to 10~12MPa, then heats it to 400~650℃ using a carbon dioxide heating device. The fluid is then expanded by a turbine expander, maintaining the working fluid pressure at 7.4~7.5MPa and the temperature at 200~300℃. The carbon dioxide heating device can utilize any of the following heat sources: clean fuel combustion, high-temperature waste heat, or solar-assisted heating, allowing the system to operate normally even without mains power.

[0017] In heating mode, the high-temperature and high-pressure working fluid directly enters the coil to release sensible heat; in cooling mode, the working fluid enters the coil for evaporation and heat absorption after passing through a recooler and a throttling valve.

[0018] Winter heat compensation circuit: Located after the heating circuit and before the regenerator, a separate winter heat compensation pipe is led out to the medium-pressure inlet of the turbine-compressor coaxial unit. After compression and pressurization, it is heated by the carbon dioxide heating device, enters the turbine expander to expand and do work, and then enters the heating circuit again to match the winter heat load demand.

[0019] The overall architecture is as follows:

[0020] 3.2.1 Envelope Heat Exchange Subsystem

[0021] It includes a double-layered sealed cavity attached to the surface of the target space enclosure structure, formed by an outer enclosure panel and an inner enclosure panel spaced apart. The cavity thickness is 60~200mm, and a microchannel heat exchange coil is installed inside the cavity. Carbon dioxide working fluid flows inside the coil, and it indirectly exchanges heat with the dry air (moisture content ≤5g / kg) circulating in a closed loop inside the cavity.

[0022] The cavity features a directional circulation structure in the airflow direction: the inner cladding panel adjacent to the inner side of the target space serves as the air supply section, while the outer cladding panel adjacent to the outer side serves as the air return section. The air supply section is wider than the air return section. The air supply section accommodates the microchannel heat exchange coils and ensures that the temperature-controlled dry air flows uniformly across the surface of the inner cladding panel at a low velocity. The air return section serves only as a return airflow channel, its width limited to allow for return air circulation, thus minimizing thermal disturbance to the outer cladding panel. The temperature-controlled dry air is driven by a pneumatic fan, first flowing directionally along the air supply section (inner cladding panel surface), where it undergoes sufficient heat exchange with the inner cladding panel before turning towards the air return section (inner surface of the outer cladding panel) and returning, forming an "inner supply, outer return" directional circulation. This structure ensures a uniform temperature field on the inner cladding panel surface while utilizing the air return section as a buffer layer to resist external climate fluctuations.

[0023] The outer cladding of the non-transparent parts is made of lightweight metal sheet, and the inner cladding is made of lightweight insulation sheet; the transparent parts use transparent cladding components, with a directional circulating interlayer between them and the inner layer.

[0024] The cavity is equipped with a filling port, which allows for the initial filling of the system or replenishment after maintenance by introducing dried external air into the cavity in one go. During operation, the air circulates in a completely sealed manner, isolating it from the outside atmosphere. The cavity is divided into multiple independent zones according to orientation or area, and each zone is equipped with an independent pneumatic ventilation unit and temperature sensor, which are independently controlled by the global intelligent control platform.

[0025] The outer cladding panel and the main structure are connected by pre-embedded connectors or snap-fit ​​components to achieve flexible assembly without drilling. The connection nodes allow the panel to expand and contract freely along the plane when the temperature changes, and at the same time, it can deform in coordination with the main structure under seismic action without participating in the stiffness distribution of the main structure.

[0026] 3.2.2 High-pressure working fluid input and circulation path

[0027] The high-pressure working fluid is supplied by a local energy station. This local energy station includes a turbine-compressor coaxial unit (multi-stage compression) and a carbon dioxide heating device. Low-pressure return carbon dioxide (3.6~3.98MPa, 5~10℃) absorbs heat in the evaporator and then enters the turbine-compressor coaxial unit (driven by the turbine coaxial drive), where it is compressed to 10~12MPa. The compressed carbon dioxide then enters the carbon dioxide heating device and is heated to 400~650℃. The high-temperature, high-pressure carbon dioxide then enters the turbine expander to expand and do work, reducing its pressure to 7.4~7.5MPa and its temperature to 200~300℃ before entering the heating circuit. The mechanical work output by the turbine directly drives the turbine-compressor coaxial unit and system auxiliary equipment via coaxial transmission; excess power can be used to generate electricity for self-use.

[0028] After passing through the heating circuit, the high-pressure working fluid overcomes system resistance along the way, and its pressure drops to 7.2~7.3MPa. It then enters the regenerator to be cooled to about 35°C before entering the high-pressure carbon storage tank for buffer storage. The outlet of the high-pressure carbon storage tank forms a high-pressure energy supply pipeline.

[0029] The regenerator is installed before the inlet of the high-pressure carbon storage tank. It utilizes the waste heat from the low-pressure return gas to conduct countercurrent heat exchange with the high-temperature working fluid entering the high-pressure carbon storage tank, cooling the high-pressure working fluid to approximately 35°C, while simultaneously preheating the low-pressure return gas from 5-10°C to 10-15°C. The low-pressure return gas temperature, within the range of 10-15°C, represents the actual operating temperature after recovering low-grade waste heat along the route.

[0030] Two branches, a heating circuit and a cooling circuit, are drawn from the high-pressure power supply pipeline:

[0031] Heating circuit: In heating mode, high-temperature and high-pressure carbon dioxide is independently drawn from the high-pressure power supply pipeline, and directly enters the coil to release sensible heat through the working condition switching valve group (heating position). After releasing heat, the pressure is reduced to 7.2~7.3MPa along the way, and then returned to the high-pressure power supply pipeline through the working condition switching valve group.

[0032] Cooling circuit: In cooling mode, high-pressure carbon dioxide first enters the recooler, using low-pressure return gas as the cold source to cool to the saturation temperature of 29.3℃ corresponding to 7.1MPa, becoming a pure saturated liquid (dryness fraction). Saturated liquid carbon dioxide is throttled and depressurized to 3.6~3.98MPa via a throttling valve, then fed into the coil for evaporation and heat absorption via a switching valve assembly (cooling position). After evaporation, it returns to the low-pressure return gas line as a saturated gas via the switching valve assembly, with an evaporator outlet temperature of approximately 5℃. A pressure regulating valve is installed between the high-pressure power supply pipeline and the recooler to precisely control the working fluid pressure at 7.1MPa.

[0033] Winter heat compensation loop: After the heating loop and before the regenerator, a portion of the carbon dioxide working fluid is diverted from the high-pressure pipeline and led to the medium-pressure inlet of the turbine-compressor coaxial unit. After secondary pressurization, it returns to the carbon dioxide heating device for reheating, and then re-enters the turbine expander to perform work before being integrated into the heating loop, thereby increasing the working fluid flow rate and peak heating capacity of the heating loop. This loop is only activated as needed by the global intelligent control platform during heating operation.

[0034] 3.2.3 Low-pressure return gas pipeline and waste heat recovery

[0035] The low-pressure return gas pipeline (3.6~3.98MPa, 5~10℃) recovers the evaporation return gas from the cooling circuit and the return gas after the pneumatic branch has performed work. A low-grade waste heat exchanger is connected in series along the route to absorb waste heat and raise the temperature to 10~15℃. After preheating by the regenerator, the gas enters the inlet of the turbine-compressor coaxial unit. A deep drying filter with built-in molecular sieve adsorbent is installed at the end of the low-pressure return gas pipeline and before the inlet of the low-pressure carbon storage tank to lower the return gas dew point to below -40℃.

[0036] 3.2.4 Pneumatic Branch Circuit

[0037] The pneumatic branch draws air independently from the low-pressure return air line, and after pressure regulation by a pressure reducing valve, drives the pneumatic actuators (pneumatic fans, pneumatic sunshades, etc.). The working fluid, after performing work, is pressurized by an ejector device and returned to the low-pressure return air line. The ejector power comes from the high-pressure power supply pipeline. The pneumatic actuators are not electrically driven and continue to operate when the mains power is interrupted.

[0038] 3.2.5 Global Intelligent Control and Operation Mode

[0039] The symbols in this section are defined as follows: To anchor the target temperature value for the inner surface, The measured temperature inside the target space. This is the measured value of the external ambient temperature. This is the preset temperature offset.

[0040] The comprehensive intelligent control platform integrates a multi-zone temperature sensor array, a dew point sensor, and multiple pneumatic throttling actuators to achieve the following core control modes:

[0041] (1) Constant temperature anchoring mode: The inner surface temperature of the inner cladding panel is ≥ the dew point temperature inside the target space + 2℃ as a constraint, so that the inner surface temperature of each zone is anchored within a preset wide range.

[0042] (2) Dynamic follow-up anchoring mode: based on and Automatically calculate the optimal anchoring target :

[0043] • Cooling operation: ;

[0044] • Heating conditions: ;

[0045] • Transitional operating condition: Smooth switching of linear interpolation.

[0046] (3) Independent control mode for each zone: The opening of the throttle valve is independently controlled according to the feedback of the temperature sensor of each zone, so that the surface temperature difference of each zone is controlled within ±1℃.

[0047] (4) Low temperature holding mode: In intermittent use scenarios, the inner surface temperature is switched to 5~10℃ during periods when there is no one or no stock, and only a small amount of antifreeze is maintained; automatic and rapid preheating / precooling is performed before use resumes.

[0048] As a preferred option, the target space is equipped with a carbon dioxide concentration sensing and alarm device (safe threshold 1000ppm), which is linked with the whole-domain intelligent control platform to achieve on-demand supply of fresh air.

[0049] 3.2.6 Energy cascade utilization

[0050] The closed-loop carbon dioxide cycle described in this invention forms a five-level utilization chain in terms of energy quality:

[0051] High-grade heat source drive: In the local energy station, the low-pressure return gas is pressurized to 10~12MPa by the turbine-compressor coaxial unit (multi-stage compression), and heated to 400~650℃ by the carbon dioxide heating device, which drives the turbine expander to output mechanical work, the temperature drops to 200~300℃, and the pressure is controlled to 7.4~7.5MPa.

[0052] First stage (thermal energy utilization): The high-temperature working fluid (200~300℃, 7.4~7.5MPa) from the turbine outlet enters the heating circuit. After the sensible heat is released by the coil, the pressure drops to 7.2~7.3MPa and the temperature drops to 50~60℃. In winter heating conditions, the winter heat compensation circuit is activated to increase the heat supply. Different users can add other heating branches such as domestic hot water as needed.

[0053] Second stage (regenerative heating): The working fluid (50~60℃) enters the regenerator and exchanges heat with the low-pressure return gas (10~15℃) in a countercurrent flow, cooling the high-pressure side working fluid to about 35℃, while preheating the low-pressure return gas.

[0054] Third stage (throttling refrigeration): The recooler uses low-pressure return gas as a cold source to cool the high-pressure working fluid to a saturated liquid state at 7.1 MPa and 29.3℃ (dryness fraction). After being depressurized by the expansion valve, the heat enters the coil for evaporation and heat absorption. Different users can add other cooling branches as needed, such as integrated fresh air units, refrigeration, and cold storage units.

[0055] Level 4 (Pneumatic Branch): Utilizing return air pressure, it can provide pneumatic power (0.6~1.0MPa) for the user's pneumatic equipment.

[0056] Fifth stage (waste heat recovery): 5~10℃ Low-pressure return gas absorbs low-grade waste heat from equipment rooms, transformer rooms, auxiliary rooms, etc. along the way, and enters the regenerator after being heated to 10~15℃.

[0057] The above-mentioned five-stage energy cascade utilization does not require an external cold source, and relies entirely on the coupling of working fluids at different temperature levels within the system itself, thereby reducing the grade requirements of external energy supply.

[0058] 3.3 Beneficial Effects

[0059] 1. The internal surface temperature is anchored near the target temperature (heating ≈ , cooling = The temperature is always above the dew point, physically preventing condensation. External heat loads are intercepted within the interlayer, while internal heat loads... It becomes an exact expression containing only known parameters.

[0060] 2. Independent temperature control for each zone reduces the temperature difference between zones from 10-15℃ in the traditional scheme to within ±1℃.

[0061] 3. The compression work is provided by the mechanical work output from the turbine-compressor coaxial unit in the local energy station, and the pneumatic actuators are driven by low-pressure return gas. During normal operation, the compression equipment is not powered by the power grid; only the control platform and sensors are powered by milliwatt-level weak electrical signals, which can be self-sufficient by small batteries or thermoelectric generators. This invention structurally avoids the energy loss in the electrically driven thermodynamic process, achieving a reasonable match between the energy supply quality and the demand quality.

[0062] 4. The self-weight of the enclosure structure is reduced by 85% to 90% compared with traditional concrete / masonry exterior walls; it can be prefabricated in the factory into standardized modular units, and can be quickly assembled on site without drilling, reducing the construction process from 12 to 15 steps to 5 to 6 steps.

[0063] 5. The reduced self-weight reduces seismic forces by approximately 85% to 90% compared to the same period last year; the flexible prefabricated structure allows the enclosure structure to deform in coordination with the main structure, avoiding the constraints caused by the sudden increase in stiffness of traditional infill walls.

[0064] 6. The interlayer temperature is close to the target space temperature, the temperature difference between the two sides is reduced to 0~5℃, and the heat transfer driving force is weakened to 5%~10%; the moisture content of the dry air is ≤5g / kg, and the inner surface temperature is always higher than the dew point, thus eliminating thermal bridging and condensation from a mechanistic perspective.

[0065] 7. The inner surface temperature of both sides of the partition wall of each household is independently anchored to the temperature of its own target space, the temperature difference between adjacent spaces approaches zero, and the heat transfer between households approaches zero.

[0066] 8. Utilizing lightweight, low-heat inertia panels, coupled with a low-temperature maintenance mode—maintaining the inner surface temperature at 5~10℃ during unattended periods instead of complete shutdown—the inner surface temperature returns to the set value within 30 minutes upon resumption the next day, eliminating the need for reheating or cooling the building envelope. This reduces energy consumption by 40%~50% compared to traditional 24-hour continuous operation.

[0067] 9. The five-stage energy cascade utilization eliminates the need for an external cooling source, allowing the system to be driven by low-grade waste heat, thus expanding its heat source adaptability in off-grid scenarios. Carbon dioxide, as the working fluid, naturally possesses zero ODP and extremely low GWP environmental properties. During system operation, the external surface temperature of the building envelope is significantly lower than that of traditional passive exterior walls due to active temperature control within the interlayer, drastically reducing radiative and convective heat emitted into the urban environment. Simultaneously, the system's condensation heat is recovered and utilized internally in stages rather than being released into the environment, reducing the heat source input for the urban heat island effect from both the building structure and system operation perspectives.

[0068] 10. The mass flow rate and enthalpy difference of carbon dioxide working fluid are directly measured, and the energy consumption measurement accuracy is within ±5%.

[0069] 11. The refrigerator / freezer shell achieves zero indoor emission of condensation heat, reducing air conditioning load by 20%~30% in summer; the temperature fluctuation of cold chain logistics vehicle body and ship refrigerated compartment is controlled within ±0.5℃, and waste heat can be used to drive refrigeration, reducing energy consumption by 25%~35%. Attached Figure Description

[0070] Figure 1 System overall structure diagram.

[0071] Figure 2 Partial cross-sectional view of the double-layer enclosure structure cavity and heat exchange coil. Detailed Implementation

[0072] 5.1 Example 1: Office Building

[0073] The curtain wall area of ​​a certain office building is 2500m² 2 The transparent portion uses triple-layer hollow Low-E glass, while the non-transparent portion uses an outer layer of honeycomb aluminum panel and an inner layer of foamed ceramic, with a sandwich thickness of 60mm. High-pressure carbon dioxide is supplied by a local energy station, with the high-pressure carbon storage tank operating at 7.2~7.3MPa. It employs an "internal supply, external return" directional circulation system, operating in a dynamic follow-up anchoring mode: the inner wall temperature is 20℃ in winter and 28℃ in summer. Heat loss is reduced by approximately 65%~70% during the heating season, and solar radiation heat gain is reduced by approximately 60%~65% during the cooling season.

[0074] 5.2 Example 2: High-rise residential building

[0075] This 33-story residential building uses a honeycomb aluminum panel outer layer and a foamed ceramic inner layer for the non-transparent sections, while the transparent sections feature triple-glazed, double-cavity insulated glass with a 60mm interlayer. The outer layer is flexibly assembled without drilling using pre-embedded snap-fit ​​components, and the connection nodes employ elongated hole bolts and sliding washers, allowing the panels to expand and contract with temperature changes and deform in coordination with the frame during earthquakes. The overall airtightness (n50) is ≤1.0 cycles / hour.

[0076] The self-weight is approximately 10% of that of traditional walls, and the cross-section of the main structural beams and columns can be reduced by 15% to 20% under an 8-degree seismic fortification. Dynamic response analysis shows that the acceleration response of the flexible prefabricated enclosure structure is basically consistent with that of the main structure (deviation <15%), eliminating the "weak layer" failure mechanism caused by the sudden increase in stiffness in traditional infill walls. The weighted sound insulation Rw ≥ 52 dB. The construction procedures are reduced from 12 to 6, shortening the cycle by approximately 40%.

[0077] 5.3 Example 3: Temporary Camp in Extreme Mine Environments

[0078] In high-altitude mines (-35℃), a modular double-layer color steel plate + foamed ceramic enclosure is used. Carbon dioxide circulation is achieved through on-site heat compression of a local energy station driven by waste heat from diesel generator exhaust. Dynamic tracking and anchoring keep the internal surface temperature stable at 18~20℃, maintaining an indoor temperature above 15℃, eliminating the need for additional electric heating. The modular units can be quickly disassembled and relocated, reducing overall relocation costs by approximately 60% compared to traditional solutions.

[0079] 5.4 Example 4: Transparent Dome

[0080] The large public building's glass dome is supported by a steel grid structure. The enclosure structure employs a three-pane glass construction: an outer layer, a middle layer, and an inner layer, arranged alternately. A return air cavity (12mm wide) is formed between the outer and middle layers, and a supply air cavity (90mm wide) is formed between the middle and inner layers. The supply air cavity is wider than the return air cavity. It accommodates the microchannel heat exchange coils and ensures that the temperature-controlled dry air flows uniformly across the inner glass surface at a low velocity. The return air cavity serves only as a return airflow channel; its width is limited to allow for return air circulation, minimizing thermal disturbance to the outer glass.

[0081] The pneumatic fan and microchannel heat exchange coils are centrally located in the equipment compartment at the top of the curtain wall. The equipment compartment is independently sealed and connected to the double-glazed cavity, maintaining a closed-loop circulation of dry air within the cavity. The carbon dioxide coils are fixed along metal supports in sections, positioned in the center of the air supply cavity. A certain gap is maintained between the coils and both the inner and outer glass panels, and they are secured to the side walls of the metal supports using transparent clips. The coils have an outer diameter of 4-8mm, with adjacent coils spaced 50-100mm apart and evenly distributed. The tube surface is treated with black anodizing to maximize visual transparency while ensuring heat exchange efficiency.

[0082] The system adopts an "internal supply and external return" directional circulation: airflow enters the right air supply chamber from the top equipment compartment, flows downward along the surface of the inner laminated glass, exchanges heat fully with the inner glass, turns back at the bottom, enters the left return air chamber, returns upward along the inner surface of the outer laminated glass, and returns to the inlet of the pneumatic fan in the top equipment compartment, completing a closed circulation (i.e., top air supply, bottom reversal, top return).

[0083] During cooling operation, the coil actively intercepts some of the solar radiation heat, reducing the indoor air conditioning load. During winter heating, the coil itself acts as a heat radiator, compensating for the reduced solar heat gain due to coil shading. This anchors the inner surface temperature within a comfortable range, fundamentally solving the problems of overheating in summer and condensation in winter.

[0084] 5.5 Example 5: Active temperature control housing for refrigerators / freezers

[0085] This invention applies a double-layer sealed cavity structure to the refrigerator shell, using an outer metal plate as the outer protective layer and an inner liner as the inner protective layer, forming a 30-60mm sealed cavity. A microchannel heat exchange coil is installed inside and filled with sealed circulating dry air. The condenser coil is located at the air inlet; condensation heat is carried away by the circulating air, exchanged through the carbon dioxide coil, and then discharged through the low-pressure return air pipeline. The refrigerator's internal wall temperature is actively anchored to the set temperature (2-8℃ for refrigeration, -18 to -25℃ for freezing) by a fully intelligent control platform, with temperature fluctuations within ±0.5℃. Compared to traditional polyurethane foam refrigerators, it saves 15%-25% energy, has zero indoor heat emission from condensation, and reduces air conditioning load by 20%-30% in summer.

[0086] 5.6 Example 6: Active temperature-controlled box for cold chain logistics vehicle

[0087] This invention applies the double-layer sealed cavity structure to the body of a cold chain logistics vehicle. The body panels are prefabricated sandwich panels, with an outer skin as the outer cladding and an inner skin as the inner cladding, forming a 50-100mm sealed cavity. Internal microchannel heat exchange coils and dry air circulation channels are installed. Each panel unit is prefabricated in the factory as a standard modular unit, and rapid assembly is performed on-site using pre-embedded connectors. The panel seams are continuously sealed with weather-resistant sealant. The airtightness and thermal insulation performance meet the relevant requirements of GB / T 40475-2021 and GB / T 22918-2025.

[0088] The carbon dioxide working fluid is supplied by the onboard local energy station and can be driven by waste heat from the exhaust of the fuel engine. In cooling mode, the temperature of the inner wall of the box is actively anchored at -18~-25℃ (freezing) or 0~4℃ (refrigeration). The "internal supply and external return" directional circulation ensures that the cooling capacity is evenly distributed throughout the entire box. Compared with traditional polyurethane foam refrigerated truck boxes: the box weight is reduced by 20%~30%, the overall vehicle curb weight is reduced by about 10%~15%; temperature fluctuation is within ±0.5℃; and refrigeration energy consumption is reduced by 25%~35%.

[0089] 5.7 Example 7: Active Temperature Control Enclosure System for Ship Refrigerated Compartments

[0090] This invention applies the double-layer sealed cavity structure to the enclosure structure of a ship's refrigerated compartment. The bulkhead uses prefabricated sandwich panels, with an outer metal plate as the outer enclosure panel and an inner stainless steel plate as the inner enclosure panel, forming a 50-120mm sealed cavity. Internal microchannel heat exchange coils and dry air circulation channels are installed within the cavity. The panel seams are continuously sealed with marine-grade weather-resistant sealant to meet salt spray environment requirements.

[0091] The carbon dioxide working fluid is supplied by the ship's local energy station and can be driven by waste heat from the main engine cylinder liner water or exhaust gas. In cooling mode, the temperature of the inner surface of the bulkhead is actively anchored to the target value of refrigeration (0~4℃) or freezing (-18~-25℃). Compared with traditional cork / polyurethane foam refrigerated compartments: temperature fluctuation is within ±0.5℃, refrigeration energy consumption is reduced by 25%~35%, and dependence on shipboard electricity is significantly reduced.

[0092] 5.8 Basis for Parameter Setting

[0093] • Turbine outlet pressure 7.4~7.5MPa / 200~300℃: Provides sufficient pressure head to overcome frictional resistance, local resistance and equipment resistance in the heating circuit.

[0094] • Regenerator inlet pressure 7.2~7.3MPa: The working fluid naturally decreases in pressure to this range after passing through the heating circuit and enters the regenerator for cooling.

[0095] • High-pressure carbon storage tank 7.2~7.3MPa / 35℃: below the critical pressure of carbon dioxide (7.38MPa), the working medium is in the subcritical dense phase region, avoiding drastic changes in physical properties.

[0096] • Recooler 7.1MPa / 29.3℃: Makes the working fluid saturated liquid ( Eliminate throttling flash loss.

[0097] • Low pressure 3.6~3.98MPa: corresponding to evaporation temperature -5℃~5℃, automatic adjustment is allowed.

[0098] • Turbine-compressor coaxial unit outlet 10~12MPa: Provides sufficient pressure drop to drive the turbine, lower than the industrial pipeline design pressure (15MPa), with ample safety margin.

Claims

1. An active enclosure structure, characterized in that, include: A double-layered sealed cavity formed by an outer cladding plate and an inner cladding plate spaced apart, the cavity being attached to the surface of the enclosure structure of the target space; a heat exchange coil disposed within the cavity, the coil containing carbon dioxide working fluid; a closed-loop carbon dioxide working fluid circulation pipeline connected to the heat exchange coil; and a global intelligent control platform. The compression work and transport power of the carbon dioxide working fluid cycle do not come from the electric motor driven by the grid electricity. The compression energy of its high-pressure working fluid is generated by the mechanical work output by the turbine-compressor coaxial unit in the local energy station. The full-domain intelligent control platform is used to adjust the flow rate of the working fluid, so that the temperature of the inner surface of the inner cladding is anchored within a preset temperature range.

2. The active enclosure structure according to claim 1, characterized in that, The cavity is equipped with a filling port, which is used to fill the cavity with dried external air as closed-loop dry air during initial system filling or replenishment after maintenance. During operation, the air circulates completely in a closed loop within the cavity, isolating it from the external atmosphere.

3. The active enclosure structure according to claim 1, characterized in that, The heat exchange coil is equipped with a mode switching valve group at its inlet and outlet. The mode switching valve group switches the coil to the cooling circuit in cooling mode and to the heating circuit in heating mode, so as to realize dual-mode operation of the same coil.

4. The active enclosure structure according to claim 1, characterized in that, The double-layer sealed cavity is provided with an air supply section and a return section in the direction of air flow. The temperature-controlled dry air is driven by a pneumatic fan. It first flows directionally along the air supply section on the surface of the inner cladding panel, exchanges heat with the inner cladding panel, and then turns to the return section on the inner surface of the outer cladding panel and returns, forming a directional circulation structure.

5. The active enclosure structure according to claim 1, characterized in that, The outer cladding panel is connected to the main structure through pre-embedded connectors or snap-fit ​​components to achieve flexible assembly without drilling. This allows the panel to expand and contract freely along the plane when the temperature changes, and it can also deform in coordination with the main structure under seismic action without participating in the stiffness distribution of the main structure.

6. The active enclosure structure according to claim 1, characterized in that, The comprehensive intelligent control platform features a dynamic follow-up anchoring mode, based on the measured temperature values ​​inside the target space. With external ambient temperature Automatic calculation of anchoring target —Cooling conditions: ,in Preset temperature offset; Heating conditions: ; The surface temperature of each zone is synchronously anchored to its respective target value, and the temperature difference between each zone does not exceed ±1℃.

7. The active enclosure structure according to claim 1, characterized in that, The carbon dioxide working fluid circulation pipeline includes a high-pressure carbon storage tank, a low-pressure carbon storage tank, and a deep drying and filtration device before the low-pressure carbon storage tank. The circulation pipeline also includes a recooler and a throttling valve. The recooler uses low-pressure return gas as a cold source to cool the high-pressure carbon dioxide to a saturation temperature of 29.3°C corresponding to 7.1 MPa, making it a saturated liquid. The throttling valve is used to reduce the pressure of the saturated liquid carbon dioxide before it is sent to the coil for evaporation and heat absorption. The carbon dioxide working fluid circulation pipeline is equipped with a regenerator, located before the inlet of the high-pressure carbon storage tank. The regenerator utilizes the residual heat from the low-pressure return gas pipeline to adjust the working fluid temperature entering the high-pressure carbon storage tank to 35°C. The carbon dioxide working fluid circulation pipeline also includes a winter heat compensation loop. This loop diverts a portion of the carbon dioxide working fluid from the high-pressure pipeline after the heating circuit and before the regenerator. After secondary pressurization by the turbine-compressor coaxial unit, it returns to the carbon dioxide heating device for reheating, thereby increasing the working fluid flow rate and peak heating capacity of the heating circuit. This loop is only activated as needed by the global intelligent control platform during heating operation.

8. The active enclosure structure according to claim 1, characterized in that, It also includes a pneumatic branch, which independently draws air from the low-pressure return gas pipeline, drives the pneumatic actuator after the pressure is adjusted by the pressure reducing valve, and the working fluid after doing work is pressurized by the ejector device and returned to the low-pressure return gas pipeline. The ejector power comes from the high-pressure power supply pipeline; the pneumatic actuator is not electrically driven.

9. The active enclosure structure according to claim 1, characterized in that, It also includes a local energy station, which comprises a turbine-compressor coaxial unit and a carbon dioxide heating device; the inlet of the turbine-compressor coaxial unit is connected to the outlet of the low-pressure return gas pipeline, used to compress the low-pressure return gas carbon dioxide to 10~12MPa; the carbon dioxide heating device is used to heat the compressed carbon dioxide to 400~650℃; the turbine expander is used to expand and depressurize the high-temperature and high-pressure carbon dioxide to 7.4~7.5MPa; the turbine expander and the turbine-compressor coaxial unit are coaxially mechanically connected, and the mechanical work output by the turbine directly drives the turbine-compressor coaxial unit to operate.

10. A method for temperature control of an active building envelope, characterized in that, Includes the following steps: Dry air is filled into the double-layered sealed cavity and maintained in a closed loop. High-pressure working fluid is supplied from a local energy station to a closed-loop pipeline, and the compression work and transmission power do not originate from an electric motor driven by grid electricity; Switch the coil to the cooling circuit or the heating circuit according to the operating conditions; In heating mode, the high-temperature and high-pressure working fluid directly enters the coil to release sensible heat; In cooling mode, the working fluid is depressurized by the recooler and throttling valve before entering the coil for evaporation and heat absorption. The full-domain intelligent control platform automatically calculates and anchors the target based on the internal temperature of the target space and the external ambient temperature, and independently adjusts the working fluid flow of each zone to ensure that the inner surface temperature of the inner cladding is synchronously anchored to the target value, with the temperature difference between each zone not exceeding ±1℃.

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