Cross-seasonal indoor thermal environment regulation and control method based on embedded pipe wall and latent heat energy storage

Abstract

The invention discloses a cross-seasonal indoor thermal environment regulation and control method based on an embedded pipe wall and latent heat energy storage, which is characterized in that in summer, heat conducted from the outer side of a wall body to the indoor space is blocked and collected for storage, and pre-stored cold collected from the outer side of the wall body to the indoor space in winter is released to the inner side of the wall body; in winter, cold energy conducted from the outer side of the wall to the indoor space is blocked, collected and stored, and pre-stored heat collected from the outer side of the wall to the indoor space in summer is released to the inner side of the wall. Through coupling of the double-layer embedded pipe wall and graded phase change energy storage, natural cold and heat sources are collected, load of an enclosure structure is intercepted, indoor temperature is adjusted, cross-season storage and utilization of multi-grade cold and heat are achieved in combination with a heat pump, the phase change latent heat utilization rate and energy storage density are improved, and building energy consumption is reduced.

Description

Technical Field

[0001] This invention relates to the field of green and energy-saving technology for indoor thermal environment control, specifically to a cross-seasonal indoor thermal environment control method based on embedded pipe walls and latent heat storage. Background Technology

[0002] Heating and cooling energy consumption accounts for a significant portion of total building energy consumption. Buildings in hot-summer, cold-winter regions (represented by Shanghai, Wuhan, and Chongqing) and cold regions (represented by Beijing, Tianjin, and Xi'an) generally experience high cooling loads in summer and high heating loads in winter. To improve energy efficiency, reduce fossil fuel consumption, and accelerate the construction of new zero-carbon thermal systems, various heat pump systems based on natural energy sources have been widely applied to the building's heat and cold source side. However, existing systems primarily use fan coil units, radiators, or high-temperature floor radiant heating, which typically require providing high-temperature hot water or low-temperature chilled water. This leads to a mismatch between the heat pump's supply water temperature and the building's actual needs, increasing compression power consumption and operating energy consumption. Furthermore, these terminal forms struggle to directly and fully utilize low-grade renewable energy sources such as geothermal energy and air source heat pumps. For example, CN201520550922.X disclosed an energy storage air source heat pump unit, but this method often still requires significant temperature increases or decreases through the heat pump, thus hindering the development of building heating and cooling systems towards zero carbon emissions.

[0003] Wall-embedded pipe technology, as a building energy-saving technology, regulates indoor temperature by circulating water pipes within the building envelope for heat exchange. However, currently, most wall-embedded pipes use a single, centrally located pipe arrangement, making it difficult to simultaneously and effectively intercept heat and cold from the external environment while regulating the indoor temperature. Therefore, its energy-saving potential has not been fully utilized. Furthermore, wall-embedded pipes have not yet been integrated with latent heat storage devices, lacking solutions for coupling wall-embedded pipes with heat and cold compensation capabilities to utilize low-grade energy systems.

[0004] In addition, some existing technologies directly incorporate phase change materials (PCMs) within the wall structure, utilizing their heat storage and release capabilities to regulate indoor temperature. Examples include an energy-saving wall and its heat transfer and storage method disclosed in CN202211387423.4, and a solar-air thermal collector and storage integrated wall structure disclosed in CN202022540000.4. However, this method only allows for simple heat storage and release conversion using the PCMs within the wall, making it difficult to separately match and store medium-temperature heat sources and low-temperature waste heat for tiered utilization. Therefore, its effectiveness in indoor temperature control is limited.

[0005] Existing building cooling and heating systems suffer from the following problems: First, the annual cooling and heating needs of buildings are difficult to match with the cooling and heating energy contained in the natural environment in terms of energy consumption time and heat quality; second, they do not directly and effectively utilize low-grade energy sources such as geothermal energy and air energy, but still meet the cooling and heating needs of buildings through heat pump devices, lacking systems that can achieve tiered utilization of heat quality; third, there is a lack of cross-seasonal energy storage systems that can simultaneously achieve summer cooling and winter heating based on latent heat storage, thereby improving the system's energy storage density and phase change latent heat utilization rate, and a complete solution that takes into account both system efficiency and operational reliability.

[0006] Therefore, the applicant considers designing a cross-seasonal indoor thermal environment control method based on embedded pipe walls and latent heat storage to improve the above-mentioned technical problems. Summary of the Invention

[0007] In view of the shortcomings of the prior art, the technical problem to be solved by the present invention is: how to provide a method for cross-seasonal indoor thermal environment regulation based on embedded pipe walls and latent heat storage that can better utilize the heat storage and release conversion of walls to achieve cross-seasonal energy storage and utilization and indoor environmental temperature control, thereby achieving energy conservation and emission reduction effects.

[0008] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: A method for cross-seasonal indoor thermal environment control based on embedded wall and latent heat energy storage is characterized by blocking and collecting heat conducted from the outside of the wall to the inside during summer and storing it, while releasing the pre-stored cold energy collected from the outside of the wall to the inside during winter to the inside of the wall; and blocking and collecting cold energy conducted from the outside of the wall to the inside during winter and storing it, while releasing the pre-stored heat collected from the outside of the wall to the inside during summer to the inside of the wall.

[0009] This method collects and stores heat from the outer layer of the wall in summer, then supplies it to the inner layer in winter; conversely, it collects and stores cold energy from the outer layer of the wall in winter, then supplies it to the inner layer in summer. This not only utilizes the cross-seasonal conduction of heat and cold within the wall to control indoor temperature through heat storage and release, but also, during this process, the heat exchange process on the outer side of the wall blocks the heat transfer chain from the outside to the inside, providing significant protection for the heat exchange on the inner layer of the wall. This allows the heat and cold released from the inner layer of the wall to have better temperature regulation efficiency, reduces heat and cold loss, and achieves better temperature control.

[0010] Furthermore, this method relies on a cross-seasonal indoor thermal environment control method based on embedded pipe walls and latent heat storage. The integrated embedded pipe wall latent heat storage coupled heat pump cross-seasonal heating and air conditioning system includes a double-layer embedded pipe wall as the building wall. The outer layer of the double-layer embedded pipe wall is uniformly arranged with outer pipes along the vertical direction, and the inner layer of the double-layer embedded pipe wall is uniformly arranged with inner pipes along the vertical direction. The inlet and outlet of the outer pipes are connected in series through a pipe equipped with a first circulating water pump and a first-stage phase change energy storage tank to form an external wall heat exchange loop. The inlet and outlet of the inner pipes are connected in series through a pipe equipped with a second circulating water pump and a second-stage phase change energy storage tank to form an internal wall heat exchange loop. At the two ends of the external wall heat exchange loop near the first-stage phase change energy storage tank, a bypass switching pipe for external wall heat exchange is connected in parallel to the end of the external wall heat exchange loop. In the inner wall heat exchange circuits at both ends of the secondary phase change energy storage tank, on both of the two external wall heat exchange bypass switching pipelines are equipped with on / off valves. On both ends of the inner wall heat exchange circuits connected by the two external wall heat exchange bypass switching pipelines are also equipped with on / off valves. At each end of the inner wall heat exchange circuit near the secondary phase change energy storage tank, an inner wall heat exchange bypass switching pipeline is connected in parallel to the external wall heat exchange circuits near the ends of the primary phase change energy storage tank. On both of the two inner wall heat exchange bypass switching pipelines are equipped with on / off valves. On both ends of the external wall heat exchange circuits connected by the two inner wall heat exchange bypass switching pipelines are also equipped with on / off valves. The phase change temperature of the phase change material in the primary phase change energy storage tank is 25-27℃, and the phase change temperature of the phase change material in the secondary phase change energy storage tank is 15-17℃.

[0011] In this way, during the high temperatures of summer (when the outdoor temperature is higher than the phase change temperature of the primary phase change energy storage tank), closing the switching valves on the two inner wall heat exchange bypass switching pipelines and the two outer wall heat exchange bypass switching pipelines, and opening the remaining switching valves, allows the outer layer pipes and the primary phase change energy storage tank to be connected in series to form an outer wall heat exchange loop. This exchanges and stores the high-temperature heat eroded from the outside into the outer wall layer within the primary phase change energy storage tank. Simultaneously, the heat exchange in the primary phase change energy storage tank keeps the outer wall layer at a temperature of 25-27°C, blocking heat transfer between the inside and outside. At the same time, controlling the inner layer pipes and the secondary phase change energy storage tank to form an inner wall heat exchange loop allows the cold energy stored in the secondary phase change energy storage tank (which comes from the heat exchange stored in the outer layer pipes during winter) to be transferred to the inner layer pipes, keeping the inner wall layer at a temperature of 15-17°C, effectively cooling the indoor environment. In this way, it can be seen that during the process, outdoor heat undergoes two forced heat exchanges as it is conducted from the wall to the room, so that the heat is transferred in stages to the two phase change energy storage tanks. Therefore, outdoor heat cannot be transferred to the room, which greatly reduces the energy consumption for indoor temperature control in summer.

[0012] Then, during cold winter months (when the outdoor temperature is lower than the phase change temperature of the secondary phase change energy storage tank), switching control can be achieved by opening the valves on the two inner wall heat exchange bypass switching pipelines and the two outer wall heat exchange bypass switching pipelines, and closing the four valves sandwiched between the inner and outer wall heat exchange bypass switching pipelines. This allows the secondary phase change energy storage tank to be connected in series to the outer wall heat exchange circuit and connected to the outer layer pipe, exchanging and storing the low-temperature cold energy eroded to the outer layer of the wall from the outside into the secondary phase change energy storage tank. At the same time, the heat exchange of the secondary phase change energy storage tank keeps the outer layer of the wall within the range of 15-17℃, blocking heat transfer between the inside and outside. Simultaneously, the primary phase change energy storage tank is connected in series to the inner wall heat exchange circuit and connected to the inner layer pipe, transferring the heat stored in the primary phase change energy storage tank (heat stored in the summer through heat exchange with the outer layer pipe) to the inner layer pipe, keeping the inner layer of the wall within the range of 25-27℃, effectively raising the indoor temperature. Similarly, it can be seen that during the process, the outdoor cold energy undergoes two forced heat exchanges as it is transferred to the indoor space through the wall, which causes the cold energy to be transferred in stages to the two phase change energy storage tanks. Therefore, the outdoor cold energy cannot be transferred to the indoor space, which greatly reduces the energy consumption for indoor temperature control in winter.

[0013] In practical implementation, this method can also be achieved using other schemes. For example, based on the aforementioned double-layer embedded pipe wall, primary phase change energy storage tank, and secondary phase change energy storage tank, in summer, the primary phase change energy storage tank can be directly connected to the outer layer pipe in the double-layer embedded pipe wall to form a primary heat exchange pipeline, and the secondary phase change energy storage tank can be connected to the inner layer pipe in the double-layer embedded pipe wall to form a secondary heat exchange pipeline. Then, in winter, the connectors of the primary heat exchange pipeline can be directly connected to both ends of the inner layer pipe by plugging and unplugging the pipe joints, and the connectors of the secondary heat exchange pipeline can be connected to both ends of the outer layer pipe. This can also achieve the indoor environmental temperature control method of the present invention.

[0014] Furthermore, the integrated embedded pipe wall latent heat energy storage coupled heat pump cross-seasonal heating and air conditioning system also includes an independent temperature control pipeline system. The independent temperature control pipeline system includes a fan coil unit arranged indoors. The fan coil unit is connected to an indoor heat exchanger of a water-to-water heat pump unit through a pipeline equipped with a fourth circulating water pump to form a circulation. The water-to-water heat pump unit includes an indoor heat exchanger, an outdoor heat exchanger, and a compressor and an expansion valve connected between the two to form a heat pump circulation. The compressor is equipped with a compression direction switching pipeline based on a four-way valve. The outdoor heat exchanger is a water-to-water heat exchanger and has a second heat exchange side. The second heat exchange side of the outdoor heat exchanger and a three-stage phase change energy storage tank are connected in series through a pipeline equipped with a first circulating water pump to form a heat exchange loop.

[0015] Thus, when relying solely on the primary and secondary phase change energy storage tanks is insufficient for indoor temperature control, a tertiary phase change energy storage tank can be used to further assist in achieving indoor temperature control. In summer, the water-to-water heat pump unit controls the indoor heat exchanger to act as an evaporator, absorbing heat to provide cooling for the indoor fan coil units, while the outdoor heat exchanger acts as a condenser, releasing heat which is then stored in the tertiary phase change energy storage tank. Then, in winter, the water-to-water heat pump unit switches its heat pumping direction control, causing the outdoor heat exchanger to switch to evaporator mode, absorbing heat from the summer-stored heat in the tertiary phase change energy storage tank. The indoor heat exchanger then switches to condenser mode, releasing heat through the indoor fan coil units, further assisting in achieving indoor temperature control.

[0016] Furthermore, the phase change temperature of the phase change material inside the three-stage phase change energy storage tank is 19-21℃. This better meets the control requirements.

[0017] Furthermore, an outdoor water-air heat exchanger is also installed in parallel outside the three-stage phase change energy storage tank, and a switching valve is installed on the pipe directly connected to the water-air heat exchanger to realize switching control.

[0018] In this way, when the heat storage tank of the three-stage phase change energy storage tank is insufficient or full, it can directly exchange heat with the air through a water-air heat exchanger, thereby better achieving temperature control of the independent temperature control pipeline system. At the same time, the three-stage phase change energy storage tank circuit and the air source branch can be selectively opened according to the annual outdoor temperature changes to achieve efficient system operation.

[0019] Furthermore, the phase change material is an inorganic salt hydrate, an organic paraffin, or a composite phase change material thereof. This allows for precise control of the desired phase change temperature.

[0020] Furthermore, the inner and outer tubes each employ a serpentine coil or a parallel arrangement of straight tubes. This allows for better heat exchange.

[0021] Furthermore, the inner and outer tubes are made of metal or composite plastic, which allows for better heat exchange.

[0022] Furthermore, a heat insulation layer is installed between the inner and outer tubes using thermal insulation material. This better blocks heat transfer between the indoor and outdoor areas, improving the indoor insulation effect.

[0023] In summary, this invention can better utilize the heat storage and release conversion of the wall to achieve cross-seasonal indoor environmental temperature control, thus achieving better energy conservation and emission reduction effects. Attached Figure Description

[0024] Figure 1This is a schematic diagram of the structure of the latent heat storage coupled heat pump cross-seasonal heating and air conditioning system with integrated embedded pipe wall in Embodiment 1 of the present invention.

[0025] Figure 2 for Figure 1 A schematic diagram of the system's piping connections under summer operating conditions.

[0026] Figure 3 for Figure 1 A schematic diagram of the system's piping connections under winter operating conditions.

[0027] Figure 4 for Figure 1 A schematic diagram of an independent temperature control pipeline system based on a three-stage phase change energy storage tank.

[0028] Figure 5 for Figure 1 A schematic diagram of an independent temperature-controlled piping system based on a water-air heat exchanger.

[0029] Figure 6 for Figure 1 A schematic diagram of the system's control flow during the summer.

[0030] Figure 7 for Figure 1 A schematic diagram of the system's control process during winter. Detailed Implementation

[0031] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0032] Example 1: A method for cross-seasonal indoor thermal environment control based on embedded wall and latent heat storage, characterized in that, in summer, heat conducted from the outside of the wall to the inside is blocked and stored, and the cold energy collected from the outside of the wall to the inside during winter is released to the inside of the wall; in winter, cold energy conducted from the outside of the wall to the inside is blocked and stored, and the heat collected from the outside of the wall to the inside during summer is released to the inside of the wall.

[0033] This method collects and stores heat from the outer layer of the wall in summer, then supplies it to the inner layer in winter; conversely, it collects and stores cold energy from the outer layer of the wall in winter, then supplies it to the inner layer in summer. This not only utilizes the cross-seasonal conduction of heat and cold within the wall to control indoor temperature through heat storage and release, but also, during this process, the heat exchange process on the outer side of the wall blocks the heat transfer chain from the outside to the inside, providing significant protection for the heat exchange on the inner layer of the wall. This allows the heat and cold released from the inner layer of the wall to have better temperature regulation efficiency, reduces heat and cold loss, and achieves better temperature control.

[0034] In this embodiment, the method relies on a cross-seasonal indoor thermal environment control method based on embedded pipe walls and latent heat storage. See [link to relevant documentation]. Figure 1 The integrated embedded pipe wall latent heat storage coupled heat pump cross-seasonal heating and air conditioning system includes a double-layer embedded pipe wall 1 serving as the building wall. The outer layer of the double-layer embedded pipe wall has outer pipes 102 evenly distributed vertically, and the inner layer has inner pipes 103 evenly distributed vertically. The inlet and outlet of the outer pipes are connected in series through a pipe equipped with a first circulating water pump 703 and a primary phase change energy storage tank 602 to form an external wall heat exchange loop. The inlet and outlet of the inner pipes are connected in series through a pipe equipped with a second circulating water pump 702 and a secondary phase change energy storage tank 601 to form an internal wall heat exchange loop. At each end of the external wall heat exchange loop near the primary phase change energy storage tank 602, a bypass switching pipe for external wall heat exchange is connected in parallel to each end near the secondary phase change energy storage tank 601. In the internal wall heat exchange circuit, on both of the two external wall heat exchange bypass switching pipelines are equipped with on / off valves, and on / off valves are also installed at adjacent points at both ends of the internal wall heat exchange circuit connected to the two external wall heat exchange bypass switching pipelines. At each end of the internal wall heat exchange circuit near the secondary phase change energy storage tank 601, an internal wall heat exchange bypass switching pipeline is connected in parallel to the external wall heat exchange circuit near the ends of the primary phase change energy storage tank 602. On both of the two internal wall heat exchange bypass switching pipelines, on / off valves are also installed at adjacent points at both ends of the external wall heat exchange circuit connected to the two internal wall heat exchange bypass switching pipelines. The phase change temperature of the phase change material in the primary phase change energy storage tank 602 is 25-27℃, and the phase change temperature of the phase change material in the secondary phase change energy storage tank 601 is 15-17℃.

[0035] Thus, during high summer temperatures (when the outdoor temperature exceeds the phase change temperature of the primary phase change energy storage tank), closing the switching valves on the two inner wall heat exchange bypass switching pipelines and the two outer wall heat exchange bypass switching pipelines, and opening the remaining switching valves, allows control of the outer layer pipe and the primary phase change energy storage tank 602 to form an outer wall heat exchange circuit in series (see...). Figure 2 The system exchanges and stores the high-temperature heat eroded from the outside into the outer layer of the wall within the primary phase change energy storage tank 602. Simultaneously, the heat exchange in the primary phase change energy storage tank maintains the outer layer of the wall at a temperature of 25-27°C, blocking heat transfer between the inside and outside. Meanwhile, the inner layer pipe and the secondary phase change energy storage tank are connected in series to form an inner wall heat exchange loop. The cold energy stored in the secondary phase change energy storage tank (derived from heat exchange and storage in winter via the outer layer pipe) is transferred to the inner layer pipe, maintaining the inner layer of the wall at a temperature of 15-17°C, effectively cooling the indoor environment. Thus, it can be seen that during this process, outdoor heat undergoes two forced heat exchanges during its conduction through the wall to the interior, resulting in a stepped transfer of heat to the two phase change energy storage tanks. Therefore, outdoor heat cannot be transferred to the interior, significantly reducing indoor temperature control energy consumption in summer.

[0036] Then, during cold winter months (when the outdoor temperature is lower than the phase change temperature of the secondary phase change energy storage tank), switching control can be achieved by opening the switching valves on the two inner wall heat exchange bypass switching pipelines and the two outer wall heat exchange bypass switching pipelines, and closing the four switching valves sandwiched between the inner and outer wall heat exchange bypass switching pipelines. This allows the secondary phase change energy storage tank to be connected in series to the outer wall heat exchange circuit and to the outer pipe (see...). Figure 3 The system exchanges and stores the low-temperature cold energy eroded from the outside into the outer layer of the wall in a secondary phase change energy storage tank. Simultaneously, the heat exchange in the secondary phase change energy storage tank maintains the outer layer of the wall at a temperature of 15-17°C, blocking heat transfer between the inside and outside. Meanwhile, the primary phase change energy storage tank is connected in series to the inner wall heat exchange circuit and the inner layer pipes, transferring the heat stored in the primary phase change energy storage tank (from the heat stored in the outer layer pipes during summer) to the inner layer pipes, maintaining the inner layer of the wall at a temperature of 25-27°C, effectively raising the indoor temperature. It can also be seen that in this process, the outdoor cold energy undergoes two forced heat exchanges during its conduction through the wall to the interior, resulting in a stepped transfer of cold energy to the two phase change energy storage tanks. Therefore, outdoor cold energy cannot be transferred to the interior, significantly reducing indoor temperature control energy consumption in winter.

[0037] The integrated embedded pipe wall latent heat storage coupled heat pump cross-seasonal heating and air conditioning system also includes an independent temperature control piping system (see...). Figure 4 The independent temperature control piping system includes a fan coil unit 2 located indoors. The fan coil unit 2 is connected to an indoor heat exchanger of a water-to-water heat pump unit 3 via a piping system equipped with a fourth circulating water pump 704. The water-to-water heat pump unit 3 includes an indoor heat exchanger 31, an outdoor heat exchanger 32, and a compressor 33 and an expansion valve 34 connected between the two to form a heat pump cycle. The compressor is equipped with a compression direction switching piping 35 based on a four-way valve. The outdoor heat exchanger is a water-to-water heat exchanger and has a second heat exchange side. The second heat exchange side of the outdoor heat exchanger and a three-stage phase change energy storage tank 5 are connected in series via a piping system equipped with a first circulating water pump 701 to form a heat exchange loop.

[0038] Thus, when relying solely on the primary and secondary phase change energy storage tanks is insufficient for indoor temperature control, a tertiary phase change energy storage tank can be used to further assist in achieving indoor temperature control. In summer, the water-to-water heat pump unit 3 controls the indoor heat exchanger to function as an evaporator, absorbing heat to provide cooling for the indoor fan coil units 2, while the outdoor heat exchanger functions as a condenser, releasing heat which is then stored in the tertiary phase change energy storage tank. Then, in winter, the water-to-water heat pump unit 3 switches its heat pumping direction control, causing the outdoor heat exchanger to switch to evaporator mode, absorbing heat from the summer-stored heat in the tertiary phase change energy storage tank. The indoor heat exchanger then switches to condenser mode, releasing heat through the indoor fan coil units 2, further assisting in achieving indoor temperature control.

[0039] The phase change temperature of the phase change material in the three-stage phase change energy storage tank 5 is 19-21℃. This better meets the control requirements.

[0040] Among them, an outdoor water-air heat exchanger 4 is also installed in parallel outside the three-stage phase change energy storage tank 5. A switching valve is installed on the pipeline directly connected to the water-air heat exchanger 4 to realize switching control (see Figure 5 ).

[0041] In this way, when the heat storage tank of the three-stage phase change energy storage tank is insufficient or full, it can directly exchange heat with the air through a water-air heat exchanger, thereby better achieving temperature control of the independent temperature control pipeline system. At the same time, the three-stage phase change energy storage tank circuit and the air source branch can be selectively opened according to the annual outdoor temperature changes to achieve efficient system operation.

[0042] The phase change material is an inorganic salt hydrate, an organic paraffin, or a composite material thereof. This allows for precise control of the desired phase change temperature.

[0043] The inner and outer tubes each employ a serpentine coil or a parallel arrangement of straight tubes, which allows for better heat exchange.

[0044] The inner and outer tubes are made of metal or composite plastic, which allows for better heat exchange.

[0045] The inner and outer tubes are separated by an insulation layer made of thermal insulation material. This effectively blocks heat transfer between the interior and exterior, improving indoor insulation performance.

[0046] The functions of each component and system in this scheme will be further explained in detail below.

[0047] The primary phase change energy storage tank 602 is connected to the outer pipe 102 and the first circulating water pump 703 via pipes and valves, forming a first circulation loop. In summer, it exchanges heat with the outer wall using medium-temperature cold water, intercepts indoor heat gain, and collects medium-temperature heat conducted from the outside into the outer wall. In winter, it works with the inner pipe 103 to reduce the heat transfer load on the wall envelope and provide indoor heating using medium-temperature hot water. The secondary phase change energy storage tank 601 is connected to the inner pipe 103 and the second circulating water pump 702 via pipes and valves, forming a second circulation loop. In summer, it supplies cooling to the room using low-temperature cold water and stores indoor low-temperature waste heat. In winter, it works with the outer pipe 102 to intercept cold air intrusion using low-temperature hot water and collects cold air entering the outer wall from the outside, enhancing the insulation effect of the wall envelope. The three-stage phase change energy storage tank 5 is connected to the water-to-water heat pump unit 3, the fan coil unit 2, and the third and fourth circulating water pumps 701 and 704 via pipes and valves, forming a third circulation loop. This loop is used to handle the remaining indoor cooling / heating load in summer or winter, and to centrally store the cooling capacity released by the outdoor heat exchanger of the water-to-water heat pump 3 when it acts as an evaporator or as a condenser. The water-to-air heat exchanger 4 is connected to the water-to-water heat pump unit 3, the fan coil unit 2, and the third and fourth circulating water pumps 701 and 704 via pipes and valves, forming a fourth circulation loop with outdoor air as the heat source. This loop provides auxiliary cooling / heating capacity in air source mode when the outdoor temperature is suitable.

[0048] From the perspective of phase change material (PCM) temperature, the first-stage PCM storage tank 602 is filled with PCM material with a PCM temperature of 25-27℃. In summer, the outer tube 102 intercepts indoor heat gain, storing and collecting ambient heat (air heat and solar radiation). In winter, the inner tube 103 provides indoor heating, storing and collecting low-temperature waste heat. The second-stage PCM storage tank 601 is filled with PCM material with a PCM temperature of 15-17℃. In summer, the inner tube 103 provides indoor cooling, storing and collecting low-temperature waste cold. In winter, the outer tube 102 intercepts indoor heat loss, storing and collecting ambient cold (air cold and sky radiation). The third-stage PCM storage tank 5 is filled with PCM material with a PCM temperature of 19-21℃. It is used to store and balance the heat and cold released from the evaporator or condenser side of the heat pump in the three-stage loop. The phase change material can be inorganic salt hydrate, organic paraffin or their composite material. The latent heat storage device is preferably a packed bed phase change storage device with phase change material filled in the form of spherical capsules to increase the heat exchange area and improve the heat charge and release rate. Other forms such as cylindrical, plate-type packed structures or shell-and-tube phase change heat exchange devices can also be used as needed.

[0049] In implementation, the outer pipe 102 and inner pipe 103 of the double-layer embedded pipe wall 1 are arranged at different depths in the non-structural layer of the wall, and the pipes are isolated from each other by an insulation layer. The outer pipe 102 is set on the outdoor side to absorb the heat and cold caused by solar radiation, sky radiation, and outdoor air temperature fluctuations, thus playing a role in thermal insulation and reducing the thermal load on the building envelope. The inner pipe 103 is set on the indoor side and serves as the terminal for radiant cooling / heating, regulating the indoor air temperature and the inner surface temperature of the building envelope through a small temperature difference, thereby improving indoor thermal comfort. The outer pipe 102 and inner pipe 103 can adopt a serpentine coil or a parallel straight pipe structure, and the material can be metal pipe or composite plastic pipe, the specific form of which can be selected according to the building structure and construction conditions.

[0050] In implementation, the integrated embedded pipe wall latent heat energy storage coupled heat pump cross-seasonal heating and air conditioning system also includes temperature sensors installed indoors, outdoors, in the phase change materials of the first-stage phase change energy storage tank 602, the second-stage phase change energy storage tank 601, and the third-stage phase change energy storage tank 5, and at the outlet water. Each temperature sensor is connected to a controller, which is connected to each switching valve and each circulating water pump. The controller is used to collect temperature through the temperature sensors at various locations, automatically determine the current operating conditions, and switch the operating states of each switching valve and circulating water pump to achieve the following control operation process.

[0051] During summer operation, the control process includes the following steps (see...). Figure 6 ): Step S1: Collect indoor temperature, phase change material temperature of primary phase change energy storage tank 602, secondary phase change energy storage tank 601, tertiary phase change energy storage tank 5, outlet water temperature, and outdoor ambient temperature to determine whether there is a cooling demand, i.e., whether the indoor temperature is higher than the set upper limit of cooling temperature.

[0052] Step S2: When there is a cooling demand, the first circulation loop (i.e., the external wall heat exchange loop) is opened first, connecting the outer pipe 102 to the primary phase change energy storage tank 602. Medium-temperature chilled water, close to the primary phase change temperature (approximately 25-27°C), is then pumped into the outer pipe 102 via the first circulating water pump 703. In summer, the outer pipe 102 exchanges heat with outdoor air and solar radiation. On the one hand, it intercepts heat transfer from the outside to the inside, reducing the cooling load on the building envelope; on the other hand, it absorbs medium-temperature heat from solar radiation and outdoor air, raising the return water temperature and transporting it to the primary phase change energy storage tank 602. Latent heat is stored near its phase change temperature, achieving the collection and cross-seasonal storage of medium-temperature heat.

[0053] Step S3: While the first circulation loop is running, the second circulation loop (i.e., the inner wall heat exchange loop) is opened, connecting the inner tube 103 to the secondary phase change energy storage tank 601. Low-temperature chilled water close to the secondary phase change temperature (approximately 15~17℃) is introduced into the inner tube 103 through the second circulation water pump 702. The low-temperature chilled water undergoes radiative heat exchange with the interior through the inner tube 103, providing cooling for the interior. After absorbing heat from the interior, the water returns to its original temperature and is then transported to the secondary phase change energy storage tank 601, where it stores latent heat near its phase change temperature. This achieves the collection and storage of low-temperature waste heat from the interior, while simultaneously providing basic cooling for the building's interior.

[0054] Step S4: After the first and second circulation loops have been running normally for a period of time, the controller determines whether the indoor temperature has dropped to the set range. If the indoor temperature meets the set cooling temperature and the temperature fluctuation is within the allowable range, the controller will only operate through the first and second circulation loops and will not activate the three-stage phase change energy storage tank 5 and the water-to-water heat pump unit 3 to reduce the compressor running time and reduce energy consumption. If the indoor temperature is still significantly higher than the set value, it indicates that the cooling capacity provided by the first and second circulation loops is insufficient, and the third circulation loop will be activated.

[0055] Step S5: If the indoor temperature still hasn't reached the set cooling temperature after the first and second circulation loops have been running continuously, it indicates a significant remaining cooling demand. At this point, the controller first determines the air source operating conditions based on the outdoor ambient temperature: When the outdoor temperature is higher than the preset high temperature threshold, in order to avoid a significant decrease in the efficiency of the air source heat pump, the three-stage phase change energy storage tank 5 is activated first in conjunction with the water-water heat pump unit 3, and the air source branch of the water-air heat exchanger 4 is temporarily not activated; when the outdoor temperature is lower than the threshold and the air source operating conditions are good, the air source branch is switched to provide cooling, and it works with the three-stage phase change energy storage tank 5 to share the remaining cooling load.

[0056] Step S6: When priority conditions are met and indoor cooling is required, the controller starts the third circulating water pump 703, connecting the three-stage phase change energy storage tank 5 to the water-to-water heat pump unit 3 and the fan coil unit 2. The water-to-water heat pump unit 3 operates in cooling mode, releasing heat through the condenser to the three-stage phase change energy storage tank 5 or other water-side loops, and providing cooling capacity to the fan coil unit 2 through the evaporator. The fan coil unit 2 then supplies air to the room for cooling. Simultaneously, the three-stage phase change energy storage tank 5 stores and regulates the heat released from the heat pump's condenser side to mitigate the impact of load fluctuations on unit operation.

[0057] Step S7: When the temperature of the three-stage phase change energy storage tank 5 reaches the preset upper limit, the cooling capacity reserve is insufficient, and there is still a large cooling load indoors, the controller determines whether it is appropriate to activate the air source mode based on the outdoor ambient temperature. When the outdoor temperature is within the allowable range, the water-to-water heat pump unit 3 is connected to the water-to-air heat exchanger 4 by switching the relevant valves, and the outdoor air is used as the cold source to operate the air source cooling mode, and the fan coil unit 2 supplies cooling to the room; when the outdoor temperature is too high and the air source efficiency is significantly low, the three-stage phase change energy storage tank 5 can be used in conjunction with the water-to-water heat pump unit 3, and the air source branch is only used as a supplement during peak load periods.

[0058] During the summer transition season or when the cooling load is low, the controller can activate only the first and second circulation loops. The indoor cooling demand can be met by using the double-layer embedded pipe wall 1, the primary phase change energy storage tank 602, and the secondary phase change energy storage tank 601. There is no need to start the water-to-water heat pump unit 3 and the air source branch, thereby further reducing the system energy consumption.

[0059] During winter operation, the control process includes the following steps (see...). Figure 7 ): Step S8: Collect indoor temperature, phase change material temperature of primary phase change energy storage tank 602, secondary phase change energy storage tank 601, tertiary phase change energy storage tank 5, outlet water temperature, and outdoor ambient temperature to determine whether there is a heating demand, i.e. whether the indoor temperature is lower than the set heating temperature lower limit.

[0060] Step S9: When there is a heating demand, the controller prioritizes using a two-stage loop for heating regulation: the outer pipe 102 is connected to the secondary phase change energy storage tank 601, and low-temperature hot water close to the secondary phase change temperature (e.g., about 15~17℃) is introduced through the second circulating water pump 703. In winter, the outer pipe 102 intercepts heat loss from the room to the outside, reducing the heat load on the building envelope, and absorbs low-temperature cold energy such as outdoor air and cold radiation from the sky, thereby lowering the return water temperature and delivering it to the secondary phase change energy storage tank 601, where latent heat is stored near its phase change temperature, realizing the collection and cross-seasonal storage of low-temperature cold energy.

[0061] Step S10: While the first circulation loop is running, the second circulation loop is activated. The inner tube 103 is connected to the first-stage phase change energy storage tank 602. Medium-temperature hot water close to the first-stage phase change temperature (e.g., about 25~27℃) is introduced through the first circulating water pump 702. The medium-temperature hot water undergoes radiant heat exchange with the room through the inner tube 103 to provide indoor heating. After absorbing indoor cooling, the return water temperature decreases and is transported to the first-stage phase change energy storage tank 602, where latent heat is stored near its phase change temperature. This achieves the collection and storage of residual cooling in the room and simultaneously completes the basic heating of the building's interior. If the indoor temperature has recovered to the set range under the above operation, the third-stage phase change energy storage tank 5 and the water-to-water heat pump unit 3 are temporarily not activated.

[0062] Step S11: If the indoor temperature still hasn't reached the set heating temperature after the first and second circulation loops have been running continuously, it indicates a significant remaining heating demand. At this point, the controller first determines the air source operating conditions based on the outdoor ambient temperature: When the outdoor temperature is lower than the preset low temperature threshold (e.g., the temperature set to prevent frost), in order to avoid frequent frost formation and significant efficiency loss of the air source heat pump, the three-stage phase change energy storage tank 5 is activated first in conjunction with the water-to-water heat pump unit 3, and the air source branch of the water-to-air heat exchanger 4 is temporarily not activated; when the outdoor temperature is higher than the threshold and the air source operating conditions are good, the air source branch is switched to provide heating, and it works with the three-stage phase change energy storage tank 5 to share the remaining heating load.

[0063] Step S12: When the priority conditions are met and indoor heating is required, the controller starts the third and fourth circulating water pumps 701 and 704, connecting the three-stage phase change energy storage tank 5 with the water-to-water heat pump unit 3 and the fan coil unit 2. The water-to-water heat pump unit 3 operates in heating mode, obtaining low-grade heat from the three-stage phase change energy storage tank 5 through the evaporator, and supplying high-temperature hot water to the fan coil unit 2 via the condenser. The fan coil unit 2 then supplies air to the room for heating. The three-stage phase change energy storage tank 5 stores and balances the cooling capacity on the heat pump evaporator side within a medium temperature range, thereby balancing load fluctuations and improving system operational stability.

[0064] Step S13: When the temperature of the three-stage phase change energy storage tank 5 drops to the preset lower limit and the available heat is insufficient, but there is still a heating demand indoors, the controller decides whether to activate the air source mode based on the outdoor ambient temperature. When the outdoor temperature is higher than the low temperature threshold and suitable for the air source heat pump to operate, the water-to-water heat pump unit 3 is connected to the water-to-air heat exchanger 4 by switching the corresponding valves. The outdoor air is used as the low-temperature heat source to operate the air source heating mode, and the high-temperature hot water is still supplied to the room for heating through the fan coil unit 2. When the outdoor temperature is too low, in order to avoid frequent frosting of the air source heat pump, the operating time of the air source branch is controlled or the air source branch is shut down, and the three-stage phase change energy storage tank 5 cooperates with the water-to-water heat pump unit 3 to take priority in indoor heating.

[0065] During the above control process, the controller always uses indoor temperature as the main control quantity, and uses the phase change material temperature of each phase change energy storage tank, outlet water temperature, and outdoor ambient temperature as auxiliary criteria. It prioritizes the use of the double-layer embedded pipe wall 1 and the first-level phase change energy storage tank 602 and the second-level phase change energy storage tank 601 to carry out cooling and heating regulation and load reduction in the medium and low temperature range. Only when the cooling / heating load is large or the temperature conditions are unfavorable will the third-level phase change energy storage tank 5 be gradually activated in conjunction with the water-to-water heat pump unit 3, and the air source branch be activated when the outdoor temperature is suitable. This tiered, on-demand control strategy prioritizes the outer layer of the embedded wall for outdoor medium-temperature heat storage and the inner layer for indoor low-temperature cooling in summer, with the third-stage energy storage tank or air source heat pump used for auxiliary cooling when necessary. In winter, it prioritizes the outer layer of the embedded wall for outdoor low-temperature heat storage and the inner layer for indoor medium-temperature heating. When outdoor temperatures are low, the third-stage energy storage tank coupled with the heat pump is used first, and when outdoor temperatures are high, the operation sequence of the air source is rationally utilized. This improves the utilization efficiency of the cross-seasonal latent heat storage heating and air conditioning system, reduces the frequency of heat pump start-ups and shutdowns and operating energy consumption, and ensures the high efficiency and stability of the system throughout the year.

[0066] Example 2 is based on the double-layer embedded tube wall, primary phase change energy storage tank, and secondary phase change energy storage tank with the same structure as in Example 1. In summer, the primary phase change energy storage tank is directly connected to the outer tube of the double-layer embedded tube wall to form a primary heat exchange pipeline, and the secondary phase change energy storage tank is connected to the inner tube of the double-layer embedded tube wall to form a secondary heat exchange pipeline. Then, in winter, the connectors of the primary heat exchange pipeline are directly connected to both ends of the inner tube by plugging and unplugging the pipe joints, and the connectors of the secondary heat exchange pipeline are directly connected to both ends of the outer tube. This also achieves the indoor environmental temperature control method of the present invention.

[0067] As can be seen from the embodiments described, compared with the prior art, the present invention has the following beneficial effects: This invention incorporates a double-layered pipe-embedded wall within the building envelope. Leveraging the load interception and thermal regulation advantages of this wall, the outer and inner pipes are connected to a primary phase change energy storage tank and a secondary phase change energy storage tank, respectively. By configuring phase change materials of different temperature grades, heat from outdoor air and solar radiation is collected and stored in summer, while simultaneously providing indoor cooling using the constant temperature regulation characteristics of phase change. In winter, cold energy from outdoor air and atmospheric radiation is collected and stored, while simultaneously providing indoor heating. This forms a cross-seasonal energy cycle between building thermal regulation and thermal storage, directly utilizing low-grade energy to reduce or eliminate the building's annual thermal load, thereby reducing building operating energy consumption and improving the utilization rate of natural energy.

[0068] 2. This invention, by setting up multiple hydraulic circulation loops and combining a comprehensive judgment of indoor temperature, phase change material temperature of each phase change energy storage tank, outlet water temperature, and outdoor air temperature, prioritizes the use of the first and second circulation loops to complete the load reduction of the building envelope and indoor foundation cooling / heating. The third-stage phase change energy storage tank coupled with the water-to-water heat pump unit is only activated when there is a large cooling / heating load, and the air source branch composed of the water-to-air heat exchanger is activated when the outdoor temperature is suitable. This tiered, on-demand activation control strategy ensures that the heat pump unit operates in areas with higher efficiency and more stable operating conditions, reducing unnecessary compressor start-ups and shutdowns and energy consumption, thereby improving the overall energy efficiency of the system.

[0069] The inner layer pipes, acting as the radiant terminals of the wall, can meet indoor heating needs in winter with medium-temperature hot water, facilitating the combination with heat collected from outdoor air and solar radiation in summer. In summer, they can meet indoor cooling needs with medium-temperature cold water, facilitating the combination with cold energy collected from outdoor air and sky radiation in winter. This directly utilizes low-grade energy, eliminating the need for a heat pump to upgrade or downgrade the heat quality. The phase change energy storage tank has a significant buffering and mitigating effect on heat and cold. On one hand, it can balance the reduced efficiency or even damage to the heat pump when using an air source in extreme summer high temperatures or extreme winter low temperatures. On the other hand, it can reduce the impact of building heating / cooling load fluctuations on the heat pump's heating / cooling and start-stop frequency, improving the stability and comfort of the indoor thermal environment while also achieving energy-saving effects.

[0070] In summary, this invention can better utilize the heat storage and release conversion of the wall to achieve cross-seasonal indoor environmental temperature control, thus achieving better energy conservation and emission reduction effects.

Claims

1. A method for cross-seasonal indoor thermal environment control based on embedded pipe walls and latent heat storage, characterized in that, In summer, it blocks and collects heat conducted from the outside of the wall to the inside, and releases the pre-stored cold energy collected from the outside of the wall to the inside during winter to the inside of the wall; in winter, it blocks and collects cold energy conducted from the outside of the wall to the inside, and releases the pre-stored heat collected from the outside of the wall to the inside during summer to the inside of the wall.

2. The method for cross-seasonal indoor thermal environment control based on embedded pipe walls and latent heat storage according to claim 1, characterized in that, This method relies on a cross-seasonal indoor thermal environment control method based on embedded pipe walls and latent heat storage. The integrated embedded pipe wall latent heat storage coupled heat pump cross-seasonal heating and air conditioning system includes a double-layer embedded pipe wall as the building wall. The outer layer of the double-layer embedded pipe wall has an outer layer of pipes evenly distributed vertically, and the inner layer of the double-layer embedded pipe wall has an inner layer of pipes evenly distributed vertically. The inlet and outlet of the outer layer of pipes are connected in series with a pipeline equipped with a first circulating water pump and a first-stage phase change energy storage tank to form an external wall heat exchange loop. The inlet and outlet of the inner layer of pipes are connected in series with a pipeline equipped with a second circulating water pump and a second-stage phase change energy storage tank to form an internal wall heat exchange loop. At each end of the external wall heat exchange loop near the first-stage phase change energy storage tank, a bypass switching pipeline for external wall heat exchange is connected in parallel to the end near the second-stage phase change energy storage tank. In the inner wall heat exchange circuits at both ends of the phase change energy storage tank, on both of the two external wall heat exchange bypass switching pipelines are equipped with on / off valves. On the two ends of the inner wall heat exchange circuits connected by the two external wall heat exchange bypass switching pipelines, on / off valves are also installed at adjacent points. At each end of the inner wall heat exchange circuit near the secondary phase change energy storage tank, an inner wall heat exchange bypass switching pipeline is connected in parallel to the external wall heat exchange circuits near the two ends of the primary phase change energy storage tank. On both of the two inner wall heat exchange bypass switching pipelines are equipped with on / off valves. On the two ends of the external wall heat exchange circuits connected by the two inner wall heat exchange bypass switching pipelines, on / off valves are also installed at adjacent points. The phase change temperature of the phase change material in the primary phase change energy storage tank is 25-27℃, and the phase change temperature of the phase change material in the secondary phase change energy storage tank is 15-17℃.

3. The method for cross-seasonal indoor thermal environment control based on embedded pipe walls and latent heat storage according to claim 2, characterized in that, The integrated embedded pipe wall latent heat storage coupled heat pump cross-seasonal heating and air conditioning system also includes an independent temperature control piping system. The independent temperature control piping system includes a fan coil unit arranged indoors. The fan coil unit is connected to an indoor heat exchanger of a water-to-water heat pump unit through a pipe equipped with a fourth circulating water pump to form a circulation. The water-to-water heat pump unit includes an indoor heat exchanger, an outdoor heat exchanger, and a compressor and an expansion valve connected between the two to form a heat pump circulation. The compressor is equipped with a compression direction switching pipe based on a four-way valve. The outdoor heat exchanger is a water-to-water heat exchanger and has a second heat exchange side. The second heat exchange side of the outdoor heat exchanger and a three-stage phase change energy storage tank are connected in series through a pipe equipped with a first circulating water pump to form a heat exchange loop.

4. A method for cross-seasonal indoor thermal environment control based on embedded pipe walls and latent heat storage as described in claim 3, characterized in that, The phase change temperature of the phase change material in the three-stage phase change energy storage tank is 19-21℃.

5. A method for cross-seasonal indoor thermal environment control based on embedded pipe walls and latent heat storage as described in claim 3, characterized in that, The three-stage phase change energy storage tank is also connected in parallel to an outdoor water-air heat exchanger, and a switching valve is installed on the pipe directly connected to the water-air heat exchanger to realize switching control.

6. A method for cross-seasonal indoor thermal environment control based on embedded pipe walls and latent heat storage according to claim 2, characterized in that, The phase change material is an inorganic salt hydrate, an organic paraffin, or a composite material thereof.

7. A method for cross-seasonal indoor thermal environment control based on embedded pipe walls and latent heat storage as described in claim 2, characterized in that, The inner and outer tubes each adopt a serpentine coil or a straight tube structure arranged in parallel.

8. A method for cross-seasonal indoor thermal environment control based on embedded pipe walls and latent heat storage according to claim 2, characterized in that, The inner and outer tubes are made of metal or composite plastic.

9. A method for cross-seasonal indoor thermal environment control based on embedded pipe walls and latent heat storage according to claim 2, characterized in that, A heat insulation layer is provided between the inner and outer tubes using heat insulation material.

Images