Air conditioning system and air conditioning control method

Abstract

To provide an air conditioning system and an air conditioning control method capable of controlling air conditioning in consideration of influence of heat transfer between a skeleton and an underfloor space, in the air conditioning system using both a skeleton heat storage type radiation air conditioning system and a floor blowout air conditioning system.SOLUTION: This air conditioner is provided with a skeleton heat storage type radiation air conditioner 12 for radiating heat energy by a heat medium supplied to a pipe 24 buried in a skeleton 22 constituting a floor slab of a building to an underfloor space 26 on the skeleton 22, an air conditioner 14 for generating air-conditioned air by exchanging heat of outside air by a heat exchanger 52 and taking in return air from an indoor space 20, and a floor blowout air conditioner 16 for blowing out the air-conditioned air supplied to the underfloor space 26 from the air conditioner 14 to the indoor space 20 above. And an air conditioner control means 18 for controlling an operation output of the heat exchanger 52 on the basis of a heat flux from the skeleton 22 to the underfloor space 26, an indoor set temperature set in the indoor space 20, and an inlet air temperature of the heat exchanger 52.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an air conditioning system and an air conditioning control method that combine a building structure thermal storage type radiant air conditioning system and a floor-discharge air conditioning system. [Background technology]

[0002] Air conditioning systems for buildings have been known (see, for example, Patent Documents 1 and 2). Air conditioning loads are classified into three types: "envelope load" generated by heat transfer from outdoor spaces and solar radiation, "indoor load" generated by energy consumption indoors such as lighting and electrical outlets, and "outdoor air load" generated by taking in outdoor air.

[0003] When constructing an air conditioning system for a building, it is important to select air conditioners according to each air conditioning load and devise an efficient combination, such as a "perimeter" air conditioner that mainly handles the exterior load, an "interior" air conditioner that mainly handles the indoor load, and an "outdoor air system" air conditioner that mainly handles the outdoor air load.

[0004] In recent years, a radiant air conditioning system with thermal storage in the building structure known as TABS (Thermo Active Building System) has been attracting attention as a system that combines comfort and energy conservation. TABS is an air conditioning system in which pipes for delivering hot and cold water are buried in a concrete floor slab. The temperature of the floor slab is controlled by sending water through the pipes, and air conditioning is achieved by exchanging heat between the exposed surface of the building structure and the room.

[0005] TABS is often adopted as an interior air conditioning system that mainly handles indoor loads, and is generally combined with a separate air conditioner to handle outside air loads and envelope loads. TABS achieves high energy efficiency by increasing the surface area of ​​the building's structure that is exposed to the interior, so ducts and air conditioners are often avoided, especially near the ceiling where exposed surface areas tend to be increased, and air conditioners and air paths that handle outside air loads and envelope loads are often installed on the floor side.

[0006] On the other hand, underfloor air conditioning, which utilizes the space under the OA floor as an air conditioning chamber, is also often adopted. Underfloor air conditioning has the advantage of reducing ductwork, minimizing drafts, and making it easier to accommodate layout changes.

[0007] Against this background, there has been an increase in the adoption of air conditioning systems that combine TABS with underfloor air conditioning. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Patent Publication No. 2022-136132 [Patent Document 2] Patent No. 6250076 Summary of the Invention [Problem to be solved by the invention]

[0009] In an air conditioning system that combines TABS and underfloor air conditioning, if the top surface of the floor slab frame is not insulated, air from the underfloor space can flow near the temperature-controlled frame, affecting the temperature of the air supplied from the underfloor space to the room.In addition, the exchange of heat between the frame and the air in the underfloor space can lead to energy loss.

[0010] Furthermore, when the outdoor air load is completely processed by the cooling / heating coil of the outdoor air conditioner and then supplied to the space under the floor, if the heat exchange between the building structure and the space under the floor is not fully taken into consideration, the indoor temperature may deviate from the target temperature for a long period of time.

[0011] For this reason, in air conditioning systems that combine a thermal energy storage type radiant air conditioning system (TABS) and an underfloor air conditioning system, there was a need for a method of air conditioning control that fully takes into account the effects of heat exchange between the structure and the space under the floor.

[0012] The present invention has been made in consideration of the above, and aims to provide an air conditioning system and an air conditioning control method that are capable of controlling air conditioning while taking into account the influence of heat exchange between the building structure and the underfloor space in an air conditioning system that combines a building structure heat storage type radiant air conditioning system and a floor-discharge air conditioning system. [Means for solving the problem]

[0013] In order to solve the above-mentioned problems and achieve the object, the air conditioning system of the present invention is an air conditioning system comprising: a structural body heat storage type radiant air conditioning device that radiates thermal energy stored in the structural body by a heat medium supplied to piping embedded in the structural body that constitutes the floor slab of a building into the underfloor space above the structural body; an air conditioner that generates conditioned air by heat exchanging fresh air taken in from outdoors using a heat exchanger, while taking in return air from the indoor space; and a floor-blowout air conditioning device that blows the conditioned air supplied from the air conditioner to the underfloor space above into the indoor space, and is characterized by having an air conditioner control means that controls the operating output of the heat exchanger based on the heat flux from the structural body to the underfloor space, the indoor set temperature set in the indoor space, and the inlet air temperature of the heat exchanger.

[0014] In addition, another air conditioning system according to the present invention is characterized in that, in the above-mentioned invention, it has a structure heat storage control means that controls the supply amount of the heat medium based on a comparison between the allowable surface temperature of the structure, which is set based on the indoor set temperature, and the measured value of the surface temperature of the structure, and the air conditioner control means controls the operating output of the heat exchanger based on a comparison between the allowable indoor temperature, which is set based on the indoor set temperature, and the measured value of the return air temperature.

[0015] Another air conditioning system according to the present invention is characterized in that, in the above-mentioned invention, the air conditioner control means, during cooling, when the allowable indoor temperature exceeds the measured value of the return air temperature and the outdoor air load to be treated exceeds the expected outdoor air load of the building, sets the operating output of the heat exchanger of the air conditioner and controls the heat exchanger to operate at the set operating output, while, during heating, when the allowable indoor temperature is below the measured value of the return air temperature and the outdoor air load to be treated exceeds the expected outdoor air load of the building, sets the operating output of the heat exchanger of the air conditioner and controls the heat exchanger to operate at the set operating output.

[0016] In addition, the air conditioning control method of the present invention is an air conditioning control method for an air conditioning system that includes a structural body heat storage type radiant air conditioning device that radiates thermal energy stored in the structural body that constitutes the floor slab of a building to the underfloor space above the structural body using a heat medium supplied to piping embedded in the structural body, an air conditioner that generates conditioned air by heat exchanging fresh air taken in from outdoors using a heat exchanger while taking in return air from an indoor space, and a floor-blowout air conditioning device that blows the conditioned air supplied from the air conditioner to the underfloor space above into the indoor space, and is characterized by having an air conditioner control step that controls the operating output of the heat exchanger based on the heat flux from the structural body to the underfloor space, the indoor set temperature set in the indoor space, and the inlet air temperature of the heat exchanger.

[0017] Furthermore, another air conditioning control method according to the present invention is characterized in that, in the above-mentioned invention, it includes a structure heat storage control step of controlling the amount of heat medium supplied based on a comparison between the allowable surface temperature of the structure, which is set based on the indoor set temperature, and the measured value of the surface temperature of the structure, and the air conditioner control step controls the operating output of the heat exchanger based on a comparison between the allowable indoor temperature, which is set based on the indoor set temperature, and the measured value of the return air temperature.

[0018] Furthermore, another air conditioning control method according to the present invention is characterized in that, in the above-mentioned invention, the air conditioner control step, during cooling, if the allowable indoor temperature exceeds the measured value of the return air temperature and the outdoor air load to be treated exceeds the expected outdoor air load of the building, sets the operating output of the heat exchanger of the air conditioner and controls the heat exchanger to operate at the set operating output, while during heating, if the allowable indoor temperature is below the measured value of the return air temperature and the outdoor air load to be treated exceeds the expected outdoor air load of the building, sets the operating output of the heat exchanger of the air conditioner and controls the heat exchanger to operate at the set operating output. [Effects of the Invention]

[0019] According to the air conditioning system of the present invention, the air conditioning system comprises a structural body heat storage type radiant air conditioning device that radiates thermal energy stored in the structural body to the underfloor space above the structural body using a heat medium supplied to piping embedded in the structural body that constitutes the floor slab of the building into the underfloor space above the structural body, an air conditioner that generates conditioned air by heat exchanging fresh air taken in from outdoors using a heat exchanger while taking in return air from the indoor space, and an underfloor discharge air conditioning device that blows the conditioned air supplied from the air conditioner to the underfloor space above into the indoor space, and has an air conditioner control means that controls the operating output of the heat exchanger based on the heat flux from the structural body to the underfloor space, the indoor set temperature set in the indoor space, and the inlet air temperature of the heat exchanger.Therefore, in an air conditioning system that combines a structural body heat storage type radiant air conditioning method and an underfloor discharge air conditioning method, it is possible to achieve the effect of air conditioning control that takes into account the influence of heat exchange between the structural body and the underfloor space.

[0020] In addition, another air conditioning system according to the present invention has a structure heat storage control means that controls the amount of heat medium supplied based on a comparison between the allowable surface temperature of the structure, which is set based on the indoor set temperature, and the measured value of the surface temperature of the structure, and the air conditioner control means controls the operating output of the heat exchanger based on a comparison between the allowable indoor temperature, which is set based on the indoor set temperature, and the measured value of the return air temperature, thereby achieving the effect of enabling efficient air conditioning control.

[0021] In addition, according to another air conditioning system of the present invention, when cooling, if the allowable indoor temperature exceeds the measured value of the return air temperature and the outside air load to be processed exceeds the expected outside air load of the structure, the air conditioner control means sets the operating output of the heat exchanger of the air conditioner and controls the heat exchanger to operate at the set operating output, while when heating, if the allowable indoor temperature is below the measured value of the return air temperature and the outside air load to be processed exceeds the expected outside air load of the structure, the air conditioner control means sets the operating output of the heat exchanger of the air conditioner and controls the heat exchanger to operate at the set operating output, thereby achieving the effect of being able to perform air conditioning control that takes into account the influence of heat exchange between the structure and the underfloor space when cooling and heating.

[0022] Furthermore, according to the air conditioning control method of the present invention, there is provided an air conditioning control method for an air conditioning system including a structural body heat storage type radiant air conditioning device that radiates thermal energy stored in the structural body to the underfloor space above the structural body using a heat medium supplied to piping embedded in the structural body that constitutes the floor slab of the building into the underfloor space above the structural body, an air conditioner that generates conditioned air by heat exchanging fresh air taken in from outdoors using a heat exchanger while taking in return air from the indoor space, and an underfloor air conditioning device that blows the conditioned air supplied from the air conditioner to the underfloor space above into the indoor space, and the method includes an air conditioner control step that controls the operating output of the heat exchanger based on the heat flux from the structural body to the underfloor space, the indoor set temperature set in the indoor space, and the inlet air temperature of the heat exchanger, thereby achieving the effect of enabling air conditioning control that takes into account the influence of heat transfer between the structural body and the underfloor space in an air conditioning system that combines a structural body heat storage type radiant air conditioning system and an underfloor air conditioning system.

[0023] In addition, another air conditioning control method according to the present invention includes a structure heat storage control step that controls the amount of heat medium supplied based on a comparison between the allowable surface temperature of the structure, which is set based on the indoor set temperature, and the measured value of the surface temperature of the structure, and the air conditioner control step controls the operating output of the heat exchanger based on a comparison between the allowable indoor temperature, which is set based on the indoor set temperature, and the measured value of the return air temperature, thereby achieving the effect of enabling efficient air conditioning control.

[0024] Furthermore, according to another air conditioning control method of the present invention, the air conditioner control step, during cooling, if the allowable indoor temperature exceeds the measured value of the return air temperature and the outdoor air load to be processed exceeds the predicted outdoor air load of the building, sets the operating output of the heat exchanger of the air conditioner and controls the heat exchanger to operate at the set operating output, while during heating, if the allowable indoor temperature is below the measured value of the return air temperature and the outdoor air load to be processed exceeds the predicted outdoor air load of the building, sets the operating output of the heat exchanger of the air conditioner and controls the heat exchanger to operate at the set operating output, thereby achieving the effect of being able to perform air conditioning control that takes into account the influence of heat exchange between the building and the underfloor space during cooling and heating. [Brief explanation of the drawings]

[0025] [Figure 1] FIG. 1 is a schematic diagram showing an embodiment of an air conditioning system according to the present invention. [Figure 2] FIG. 2 is an explanatory diagram of each variable during cooling. [Figure 3] FIG. 3 is a flow chart showing the control of water supply to the TABS during cooling. [Figure 4] FIG. 4 is a control flow diagram of the cooling coil of the desiccant air conditioner during cooling. [Figure 5] FIG. 5 is an explanatory diagram of each variable during heating. [Figure 6] FIG. 6 is a flow chart showing the control of water supply to the TABS during heating. [Figure 7]FIG. 7 is a control flow diagram of the heating coil of the desiccant air conditioner during heating. [Figure 8] FIG. 8(1) is a diagram showing an example of an psychrometric chart during cooling, and (2) is a schematic cross-sectional view of a desiccant air conditioner. [Figure 9] FIG. 9(1) is a diagram showing an example of an psychrometric chart during heating, and (2) is a schematic cross-sectional view of a desiccant air conditioner. [Figure 10] FIG. 10(1) is a diagram showing an example of an psychrometric chart during cooling (different desiccant air-conditioning methods), and (2) is a schematic cross-sectional view of a desiccant air-conditioner. DETAILED DESCRIPTION OF THE INVENTION

[0026] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An air conditioning system and an air conditioning control method according to an embodiment of the present invention will be described in detail below with reference to the accompanying drawings. However, the present invention is not limited to these embodiments.

[0027] As shown in Figure 1, an air conditioning system 10 according to an embodiment of the present invention includes a TABS (thermal energy storage type radiant air conditioning system) 12, a desiccant air conditioner 14, an underfloor air conditioner 16, and a control device 18, and targets an indoor space 20 of a building for air conditioning. A framework 22 constituting a floor slab is provided on the ceiling and floor of the indoor space 20.

[0028] TABS 12 dissipates thermal energy stored in the structure 22 into an underfloor space 26 above the structure 22 by using cold and hot water (heat medium) supplied to piping 24 buried in the structure 22. The structure 22 is made of reinforced concrete, and the piping 24 can be buried to any depth. The piping 24 is connected to an outdoor cold and hot water heat source 28. The cold and hot water generated in the cold and hot water heat source 28 is supplied to the piping 24 and circulates between the piping 24 and the cold and hot water heat source 28. The supply of water from the cold and hot water heat source 28 to the piping 24 is turned on and off by a control device 18.

[0029] The desiccant air conditioner 14 generates conditioned air by exchanging heat with outside air SOA taken in from outdoors using a heat exchanger, while also taking in return air RA (inside air) from an indoor space 20. This desiccant air conditioner 14 has a housing 30 placed outdoors, and inside the housing 30 are formed an air intake path 34 that takes in outside air SOA from outdoors and supplies the conditioned air as supply air SA to an air intake piping 32, and an exhaust path 40 that takes in return air RA (inside air) from the indoor space 20 via a return air port 36 and a return air piping 38 and exhausts it to the outside as exhaust air EA. The air intake path 34 and the exhaust path 40 are separated by a partition plate 42.

[0030] In the intake air passage 34, a filter 44, a precoil 46, a portion of the desiccant rotor 48, a portion of the sensible heat exchanger 50, an aftercoil 52, and an intake fan 54 are arranged in this order from upstream to downstream in the direction of introduction of the outside air SOA. The precoil 46 and the aftercoil 52 are not limited to this arrangement; they may be located immediately before the intake air (for example, downstream of the intake fan 54). The filter 44 removes dust and other foreign matter from the outside air SOA introduced into the housing 30. The precoil 46 is composed of a precooling coil 46A and a preheating coil 46B. The desiccant rotor 48 contains an adsorbent and is positioned between the intake air passage 34 and the exhaust air passage 40. The desiccant rotor 48 can move between the intake air passage 34 and the exhaust air passage 40 by rotating. For example, during cooling, the portion of the desiccant rotor 48 located in the intake air passage 34 adsorbs and dehumidifies moisture contained in the outside air SOA flowing through the intake air passage 34. The sensible heat exchanger 50 is disposed across the intake air duct 34 and the exhaust air duct 40 and exchanges sensible heat between the outside air SOA flowing through the intake air duct 34 and the return air RA flowing through the exhaust air duct 40. The after-coil 52 is composed of a cooling coil 52A and a heating coil 52B (heat exchanger). The intake air fan 54 generates an air flow in the intake air duct 34 that sends the outside air SOA, which has been introduced from an outside air inlet 56 via a damper 58, to the intake air piping 32. In this configuration, the outside air SOA introduced from the outside air inlet 56 into the intake air duct 34 passes through the pre-coil 46, is adjusted to a predetermined humidity by the desiccant rotor 48, and then undergoes heat exchange with the after-coil 52, thereby being conditioned to a predetermined temperature. This conditioned air is sent to the intake air duct 32 and supplied to the underfloor space 26 from the intake air inlet 60 as intake air SA.

[0031] Along the exhaust path 40, an exhaust fan 62, another part of the sensible heat exchanger 50, a regenerative coil 64, and another part of the desiccant rotor 48 are arranged in this order from upstream to downstream in the exhaust direction of the inside air. The exhaust fan 62 generates an air flow in the exhaust path 40 that sends the return air RA taken in through the return air inlet 36 to the exhaust port 66. The sensible heat exchanger 50 is disposed across the supply air path 34 and the exhaust path 40, and performs sensible heat exchange between the outside air SOA flowing through the supply air path 34 and the return air RA flowing through the exhaust path 40. The regenerative coil 64 is a heat exchange coil. In this configuration, the return air RA taken into the exhaust path 40 passes through the sensible heat exchanger 50, the regenerative coil 64, and the desiccant rotor 48, and is discharged to the outdoors from the exhaust port 66 as exhaust air EA via a damper 68.

[0032] The cooling coil 52A is a coil that cools air and receives a supply of chilled water from an external heat source (not shown). The heat source includes a refrigerator and a pump whose output can be adjusted by inverter control, and chilled water is sent to the cooling coil 52A using the pump's discharge pressure. The amount of water sent to the cooling coil 52A is controlled by inverter controlling the pump and other components of the heat source. The inverter output (INV output) at this time can be determined based on the outside air load of the cooling coil 52A, the expected outside air load processed by TABS 12, and the rated capacity of the cooling coil 52A.

[0033] The heating coil 52B is a coil that heats air and receives a supply of hot water from an external heat source (not shown). The heat source includes a boiler and a pump whose output can be adjusted by inverter control, and hot water is sent to the heating coil 52B using the pump's discharge pressure. The amount of water sent to the heating coil 52B is controlled by inverter controlling the pump and other components of the heat source. The inverter output (INV output) at this time can be determined based on the outside air load of the heating coil 52B, the expected outside air load processed by TABS 12, and the rated capacity of the heating coil 52B.

[0034] The underfloor air-conditioning system 16 is composed of an underfloor space 26 that receives a supply of conditioned air (supply air SA) from the desiccant air conditioner 14 via air supply piping 32 and an air supply port 60 on the perimeter side, a floor material 72 (e.g., an OA floor) that has a plurality of air vents 70 that blow the conditioned air supplied to the underfloor space 26 into the indoor space 20 above, and an air conditioning unit 74. The air conditioning unit 74 is disposed at the back side of the underfloor space 26 and blows the conditioned air in the underfloor space 26 to the back side. The air conditioning unit 74 is composed of, for example, an air conditioner (e.g., a dry fan coil unit (DFCU)) in which a blower fan and a heat exchange coil are integrated.

[0035] The control device 18 has a building body heat storage control unit 18A and an air conditioner control unit 18B. The control device 18 can be configured to include, for example, a processing device such as a CPU and a storage device such as a memory.

[0036] The building structure heat storage control unit 18A is a building structure heat storage control means that controls the amount of hot and cold water fed (supplied) through the pipes 24 of the TABS 12 based on a comparison between the allowable surface temperature of the building structure 22, which is set based on the indoor set temperature, and the measured surface temperature of the building structure 22. The measured surface temperature of the building structure 22 is acquired via a temperature sensor (not shown) provided on the surface of the building structure 22. The indoor set temperature is a temperature that is appropriately set for the indoor space 20 by the user. The allowable surface temperature of the building structure 22 is the allowable temperature on the upper surface of the building structure 22 facing the underfloor space 26 and the allowable temperature on the lower surface of the building structure 22 facing the indoor space 20 of the lower floor, and is set based on the indoor set temperature. The allowable surface temperature of the building structure 22 is set as a lower limit during cooling and as an upper limit during heating. For this reason, the structure heat storage control unit 18A compares the allowable surface temperature of the structure 22 with the measured value of the surface temperature of the structure 22, and controls the amount of cold and hot water supplied through the pipes 24 of the TABS 12 on and off so that the measured value does not fall below the allowable surface temperature during cooling, and so that the measured value does not exceed the allowable surface temperature during heating.

[0037] The lower limit of the temperature of the top surface of the building structure 22 during cooling can be set, for example, as a value obtained by subtracting a predetermined temperature value from the indoor set temperature. This temperature value is desirably determined from the perspective of the comfort of the people living in the indoor space 20. In addition, the lower limit of the temperature of the bottom surface of the building structure 22 during cooling can be set based on the indoor set temperature, the dew point temperature of the indoor design conditions, the cooling load of the design conditions, the overall heat transfer coefficient of the upward heat flow during cooling, etc.

[0038] The upper limit of the temperature of the bottom surface of the building structure 22 during heating can be set, for example, as the indoor set temperature plus a predetermined temperature value. This temperature value is desirably determined from the perspective of the comfort of the people living in the indoor space 20. The upper limit of the temperature of the top surface of the building structure 22 during heating can be set based on the indoor set temperature, the standard outdoor air load of the design conditions, the overall heat transfer coefficient of the upper part of the building structure 22, etc.

[0039] The air conditioner control unit 18B is an air conditioner control means that controls the operating output of the cooling coil 52A and the heating coil 52B of the desiccant air conditioner 14 based on the heat flux from the building frame 22 to the underfloor space 26, the set indoor temperature, and the inlet air temperatures of the cooling coil 52A and the heating coil 52B. The heat flux is acquired via a heat flux sensor (not shown) provided on the upper surface of the building frame 22. The inlet air temperatures of the cooling coil 52A and the heating coil 52B are acquired via a temperature sensor (not shown) located upstream of and adjacent to the cooling coil 52A and the heating coil 52B. The air conditioner control unit 18B calculates the outdoor air load to be treated from the air density, specific heat of the air, outdoor air volume, inlet air temperature, and set indoor temperature, and also calculates the expected heat treatment amount (expected outdoor air load) of the building frame 22 from the heat flux on the upper surface of the building frame 22 and the heat exchange area of ​​the TABS 12. The air conditioner control unit 18B controls the operating outputs of the cooling coil 52A and the heating coil 52B based on a comparison of the calculated outside air load and the estimated heat processing amount of the building body 22.

[0040] The air conditioner control unit 18B also controls the operating output of the cooling coil 52A and the heating coil 52B based on a comparison between the allowable indoor temperature, which is set based on the indoor set temperature, and the measured return temperature (temperature of the return air RA). The allowable indoor temperature is the maximum allowable indoor temperature during cooling and the minimum allowable indoor temperature during heating. The maximum allowable indoor temperature can be set as the sum of the indoor set temperature and the dead band for the cooling coil 52A with respect to the indoor set temperature. The minimum allowable indoor temperature can be set as the indoor set temperature minus the dead band for the heating coil 52B with respect to the indoor set temperature. The measured return temperature is acquired via a temperature sensor (not shown) provided in the return air piping 38.

[0041] During cooling, if the maximum allowable indoor temperature exceeds the measured return temperature and the outdoor air load to be treated exceeds the predicted outdoor air load of the building structure 22, the operating output of the cooling coil 52A is set and the cooling coil 52A is controlled to operate at the set operating output. On the other hand, during heating, if the minimum allowable indoor temperature falls below the measured return temperature and the outdoor air load to be treated exceeds the predicted outdoor air load of the building structure 22, the operating output of the heating coil 52B is set and the heating coil 52B is controlled to operate at the set operating output. This makes it possible to perform air conditioning control that takes into account the influence of heat transfer between the building structure 22 and the underfloor space 26 during cooling and heating.

[0042] Therefore, according to this embodiment, in an air conditioning system 10 that combines a structure heat storage type radiant air conditioning system and a floor-discharge air conditioning system, air conditioning control can be performed that takes into account the effects of heat exchange between the structure 22 and the underfloor space 26.

[0043] Furthermore, the indoor load can be treated by heat exchange between the surface of the ceiling-side structure 22 and the indoor space 20, and the outdoor air load can be treated by the desiccant air conditioner 14. While it is common for all outdoor air loads to be treated by the desiccant air conditioner 14, in this embodiment, part of the outdoor air load is treated by the structure 22 under the floor.

[0044] Next, a specific control method (for cooling and heating) of the present invention will be described.

[0045] (Control method during cooling) First, the control method during cooling will be described. FIG. 2 is an explanatory diagram of each variable during cooling, FIG. 3 is a control flow diagram for water supply to the TABS 12, and FIG. 4 is a control flow diagram for the cooling coil 52A of the desiccant air conditioner 14.

[0046] The variables used in the control flow during cooling are as follows (see Figure 2): θ set :Indoor temperature setting [℃], Δθ comfort : The maximum allowable difference between the indoor set temperature and the building surface temperature from the viewpoint of comfort [℃], θ ra : Return temperature [℃], θ air : Cooling coil inlet air temperature [℃], θ floor :Structure upper surface temperature [℃], θ ceil : Lower surface temperature of the building [℃], DB: Dead zone of the cooling coil relative to the indoor set temperature [℃], θ dew_point : dew point temperature under indoor design conditions [℃], q design : Cooling load under design conditions [W / m 2 ], α ceil : Overall heat transfer coefficient of upward heat flow during cooling [W / m 2 -K](=7W / m 2 -K), q surface : Heat flux on the upper surface of the structure [W / m 2 ] (positive heat flow from underfloor air to the building frame), Q: supply air volume of desiccant air conditioner [m 3 / s], ρ: air density [kg / m 3 ](=1.2kg / m 3 ), C: specific heat of air [J / kg-K] (=1007J / kg-K), A: heat exchange area of ​​TABS [m 2 ], θ floor,min : Minimum allowable temperature of the upper surface of the structure [℃], θ ceil,min : Minimum allowable temperature of the lower surface of the structure [℃], M load : Outdoor air load of cooling coil [W], M surface : Expected outdoor air load handled by TABS [W], M coil : Rated capacity of cooling coil [W]

[0047] [Water supply control to TABS (cooling)] The water supply to the TABS 12 is controlled in accordance with steps S11 to S16 in FIG. 3 so that the surface temperature of the upper and lower parts of the slab of the building body 22 does not fall below the allowable temperature.

[0048] First, in step S11, the indoor set temperature θ set The lower limit of the slab surface temperature (θ floor,min , θ ceil,min ) is determined as shown in Figure 3. floor,min is θ set -Δθ comfort It can be calculated as follows: θ ceil,min is θ set , θ dew_point , q design , α ceil It can be calculated using Δθ comfort It is desirable to determine the value from the viewpoint of the comfort of the occupants. Standards such as ISO11855-1 Building environment design - Design, dedemensioning, installation and control of embedded radiant heating and cooling systems - indicate the dissatisfaction rate of thermal sensation in a space where the surface temperatures of each wall are asymmetric, and Δθ is calculated based on these. comfort For example, in the case of ceiling radiant cooling, the dissatisfaction rate is around 5% even if the temperature difference between the floor and ceiling is about 15°C, but in the case of ceiling radiant heating, the dissatisfaction rate reaches around 5% even if the temperature difference between the floor and ceiling is about 5°C. When cooling, the feet tend to get cold, which can increase discomfort, so Δθ comfort The value of is determined based on the intake air temperature at the feet, and θ floor,min It is preferable to determine

[0049] In the next step S12, the surface temperatures (θ floor , θ ceil ) to get the In the next step S13, the surface temperature θ floor and the lower limit θ floor,min Compare the magnitudes of θfloor >θ floor,min If so (Yes in step S13), proceed to step S14. Otherwise (No in step S13), proceed to step S16. In the next step S14, the surface temperature θ ceil and the lower limit θ ceil,min Compare the magnitudes of θ ceil >θ ceil,min If so (Yes in step S14), proceed to step S15. Otherwise (No in step S14), proceed to step S16. In step S15, the water supply to the TABS is turned on, and then the process returns to step S12. In step S16, the water supply to the TABS is turned off, and then the process returns to step S12.

[0050] [Control of cooling coils in desiccant air conditioners] On the other hand, the cooling coil 52A of the desiccant air conditioner 14 is controlled in accordance with the procedure of steps S21 to S28 in FIG.

[0051] First, in step S21, the indoor set temperature θ set and return temperature θ ra Get. In the next step S22, the maximum allowable indoor temperature (θ set +DB) and return temperature θ ra Compare the magnitudes of θ set +DB>θ ra If so (Yes in step S22), proceed to step S23. Otherwise (No in step S22), proceed to step S28. In the next step S23, the outside air flow rate Q and the air temperature θ before the cooling coil are calculated. air and the heat flux q from the top surface of the body surface Get. In the next step S24, the outdoor air load M to be processed is load and the expected heat processing capacity of the structure (expected outdoor air load) M surface As shown in Figure 4, M load are ρ, C, Q, θ air , θ setIt can be calculated using M surface , q surface , A can be used to calculate q surface can be a measurement value at one representative point, or can be set using an approximate formula calculated from multiple measurement points. Also, the heat transfer area A of TABS can be represented by the area of ​​the piping.

[0052] In the next step S25, the outdoor air load M load and the expected heat processing capacity of the structure M surface Compare the sizes of M load >M surface If so (Yes in step S25), proceed to step S26. Otherwise (No in step S25), proceed to step S27. In step S26, the INV output to the cooling coil is determined, and the cooling coil is operated with that output. Then, the process returns to step S21. As shown in FIG. 4, the INV output is load , M surface , M coil If an auxiliary heat source is provided on the indoor side, the auxiliary heat source may be operated instead of the cooling coil 52A. In this case, the output of the auxiliary heat source is determined instead of determining the INV output to the cooling coil. In step S27, the cooling coil is stopped and the INV output is set to 0. After that, the process returns to step S21. In step S28, the cooling coil is operated and the INV output is set to 100. After that, the process returns to step S21. If an auxiliary heat source is provided inside the room, the auxiliary heat source may be operated instead of the cooling coil.

[0053] As described above, the return temperature is the maximum allowable indoor temperature (θ set +DB), the INV output to the cooling coil is maximized. set +DB), the expected outdoor air load M handled by TABS surfaceThe amount of water sent to the cooling coil is controlled according to the magnitude of the value. Note that there is a lower limit for the INV output to the cooling coil, and if the calculated value of the INV output falls below this lower limit, the INV output can be set to 0 to stop the water supply.

[0054] (Control method during heating) Next, a control method during heating will be described. FIG. 5 is an explanatory diagram of each variable during heating, FIG. 6 is a control flow diagram for water supply to the TABS 12, and FIG. 7 is a control flow diagram for the heating coil 52B of the desiccant air conditioner 14.

[0055] The variables used in the control flow during heating are as follows (see Figure 5): θ set :Indoor temperature setting [℃], Δθ comfort : The maximum allowable difference between the indoor set temperature and the building surface temperature from the viewpoint of comfort [℃], θ ra : Return temperature [℃], θ air : Heating coil inlet air temperature [℃], θ floor :Structure upper surface temperature [℃], θ ceil : Lower surface temperature of the building [℃], DB: Dead zone of the heating coil relative to the indoor set temperature [℃], θ dew_point : dew point temperature under indoor design conditions [℃], q design : Standard outdoor air load under design conditions [W / m 2 ], α floor : Overall heat transfer coefficient of the upper part of the structure [W / m 2 -K](=9W / m 2 -K), q surface : Heat flux on the upper surface of the structure [W / m 2 ] (positive heat flow from underfloor air to the building frame), Q: supply air volume of desiccant air conditioner [m 3 / s], ρ: air density [kg / m 3 ](=1.2kg / m 3 ), C: specific heat of air [J / kg-K] (=1007J / kg-K), A: heat exchange area of ​​TABS [m 2 ], θ floor,max : Maximum allowable temperature of the upper surface of the structure [℃], θ ceil,max : Maximum allowable temperature of the lower surface of the structure [℃], M load :Outside air load of heating coil [W], Msurface : Expected outdoor air load handled by TABS [W]

[0056] [Water supply control to TABS (heating)] The water supply to the TABS 12 is controlled in accordance with the procedure of steps T11 to T16 in FIG. 6 so that the surface temperature of the upper and lower parts of the slab of the building body 22 does not exceed the allowable surface temperature.

[0057] First, in step T11, the indoor set temperature θ set The upper limit of the slab surface temperature (θ floor,max , θ ceil,max ) is determined as shown in Figure 6. ceil,max is θ set +Δθ comfort It can be calculated as follows: θ floor,max is θ set , q design , α floor In this way, the maximum allowable temperature of the upper part of the building during heating is different from that during cooling, and can be calculated using the standard outdoor air load q design In addition, when heating, the head side is heated, which tends to increase discomfort, so Δθ comfort The value of θ is determined by comparing the difference between the ceiling surface temperature and the floor surface temperature with the above ISO standards, etc. ceil,max It is desirable to prioritize comfort when making decisions.

[0058] In the next step T12, the surface temperatures (θ floor , θ ceil ) to get the In the next step T13, the surface temperature θ floor and upper limit θ floor,max Compare the magnitudes of θ floor <θ floor,max If so (Yes in step T13), proceed to step T14. Otherwise (No in step T13), proceed to step T16. In the next step T14, the surface temperature θ ceil and upper limit θ ceil,max Compare the magnitudes of θ ceil <θ ceil,maxIf so (Yes in step T14), proceed to step T15. Otherwise (No in step T14), proceed to step T16. In step T15, the water supply to the TABS is turned on, and then the process returns to step T12. In step T16, the water supply to the TABS is turned off, and then the process returns to step T12.

[0059] [Control of heating coils in desiccant air conditioners] On the other hand, the heating coil 52B of the desiccant air conditioner 14 is controlled in accordance with the procedure of steps T21 to T28 in FIG.

[0060] First, in step T21, the indoor set temperature θ set and return temperature θ ra Get. In the next step T22, the minimum allowable indoor temperature (θ set -DB) and return temperature θ ra Compare the magnitudes of θ set -DB<θ ra If so (Yes in step T22), proceed to step T23. Otherwise (No in step T22), proceed to step T28. In the next step T23, the outside air volume Q and the air temperature θ before the heating coil air and the heat flux q from the top surface of the body surface Get. In the next step T24, the outdoor air load M to be treated is load and the expected heat processing capacity of the structure (expected outdoor air load) M surface As shown in Figure 7, M load are ρ, C, Q, θ air , θ set It can be calculated using M surface , q surface , A can be used to calculate q surface can be a measurement value at one representative point, or can be set using an approximate formula calculated from multiple measurement points. Also, the heat transfer area A of TABS can be represented by the area of ​​the piping.

[0061] In the next step T25, the outdoor air load M load and the expected heat processing capacity of the structure M surface Compare the sizes of M load >M surface If so (Yes in step T25), proceed to step T26. Otherwise (No in step T25), proceed to step T27. In step T26, the INV output to the heating coil is determined, and the heating coil is operated at the determined output. Then, the process returns to step T21. As shown in FIG. 7, the INV output is load , M surface , M coil As with cooling, if an auxiliary heat source is installed indoors, the auxiliary heat source may be operated instead of the heating coil. In this case, instead of determining the INV output to the heating coil, the output of the auxiliary heat source is determined. In step T27, the heating coil is stopped and the INV output is set to 0. Then, the process returns to step T21. In step T28, the heating coil is operated and the INV output is set to 100. That is, the return temperature is set to the minimum allowable indoor temperature (θ set If the temperature is below -DB, the INV output to the heating coil is maximized. Then, the process returns to step T21. As in cooling mode, if an auxiliary heat source is installed inside the room, the auxiliary heat source may be operated instead of the heating coil.

[0062] (Explanation of effect) Figures 8(1) and 9(1) show examples of psychrometric charts during cooling and heating for the air-conditioning system 10 of this embodiment. Figures 8(2) and 9(2) show cross-sectional views of the corresponding desiccant air-conditioner 14. In this embodiment, the system determines and controls how to handle the portion of the outdoor air load labeled "Cooling / Heating Coil & TABS Cooling / Heating" in each psychrometric chart. This embodiment maintains a good indoor environment without wasting energy by adjusting the amount of water sent to the cooling coil 52A and heating coil 52B based on the heat flux from the floor slab frame 22 to the conditioned air in the underfloor space 26, the indoor set temperature, and the inlet air temperatures of the cooling coil 52A and heating coil 52B. Furthermore, using the desiccant air-conditioner 14 and TABS 12 in combination eliminates the need for supercooling dehumidification using chilled water below 10°C, thereby eliminating the need for low-temperature chilled water. Heat sources that produce medium-temperature chilled water (around 15 to 20°C) can be operated more efficiently than heat sources that produce low-temperature chilled water (around 6 to 9°C), making them excellent for energy conservation.

[0063] In the control of conventional desiccant air conditioners, the outside air that had completely processed the outside air load using the cooling / heating coil was supplied to the underfloor area, but this did not fully consider the heat exchange with the floor slab frame, which could result in the indoor temperature deviating from the target temperature for a long period of time. Furthermore, the heat exchange between the frame and the underfloor air could sometimes lead to energy loss. In contrast, the air conditioning control method of this embodiment can solve these problems.

[0064] (Variation) Next, a modification of this embodiment will be described. As shown in FIG. 10(2), the air conditioning system of this modified example uses a different type of desiccant air conditioner 80 instead of the desiccant air conditioner 14 in the above-described embodiment. In the air supply path 34 of this desiccant air conditioner 80, a filter 44, a part of a total heat exchanger 82, a cooling coil 52A (after-coil 52), and an air supply fan 54 are arranged in this order from upstream to downstream in the direction of introduction of outside air SOA. A partition plate 43 is provided in the exhaust path 40 to separate the exhaust path 40 into an upstream side and a downstream side, and an opening is formed between the tip of the partition plate 43 and the inner wall of the housing 30. A desiccant rotor 48 is disposed across the upstream and downstream sides of the exhaust path 40 and can move upstream and downstream along the exhaust path 40 by rotating. A part of the desiccant rotor 48 and another part of the total heat exchanger 82 are arranged in this order on the upstream side of the exhaust path 40. An exhaust fan 62, a regenerative coil 64, and another part of the desiccant rotor 48 are arranged in this order on the downstream side of the exhaust path 40. In this modification, the same air conditioning control as above is performed using this desiccant air conditioner 80. This configuration also achieves the same effects as above.

[0065] An example of an psychrometric chart during cooling in this modified example is shown in Figure 10(1). As shown in Figure 10(1), this modified example allows the TABS 12 to bear a large share of the outdoor air load. Furthermore, if the pre-cooling coil provided in the desiccant air conditioner 14 could be eliminated and the entire outdoor air load could be handled by the TABS 12, it would be possible to completely shut down the heat source for the chilled water in the desiccant air conditioner system, which would be effective in saving energy.

[0066] As described above, the air conditioning system of the present invention is an air conditioning system comprising: a structural body heat storage type radiant air conditioning device that radiates thermal energy stored in the structural body by a heat medium supplied to piping embedded in the structural body that constitutes the floor slab of the building into the underfloor space above the structural body; an air conditioner that generates conditioned air by heat exchanging fresh air taken in from outdoors using a heat exchanger, while taking in return air from the indoor space; and an underfloor discharge air conditioning device that blows the conditioned air supplied from the air conditioner to the underfloor space above into the indoor space. The air conditioning system has an air conditioner control means that controls the operating output of the heat exchanger based on the heat flux from the structural body to the underfloor space, the indoor set temperature set in the indoor space, and the inlet air temperature of the heat exchanger. Therefore, in an air conditioning system that combines a structural body heat storage type radiant air conditioning system and an underfloor discharge air conditioning system, air conditioning control can be performed that takes into account the influence of heat transfer between the structural body and the underfloor space.

[0067] In addition, another air conditioning system according to the present invention has a structure heat storage control means that controls the amount of heat medium supplied based on a comparison between the allowable surface temperature of the structure, which is set based on the indoor set temperature, and the measured value of the surface temperature of the structure, and the air conditioner control means controls the operating output of the heat exchanger based on a comparison between the allowable indoor temperature, which is set based on the indoor set temperature, and the measured value of the return air temperature, thereby enabling efficient air conditioning control.

[0068] In addition, according to another air conditioning system of the present invention, when cooling, if the allowable indoor temperature exceeds the measured value of the return air temperature and the outside air load to be processed exceeds the expected outside air load of the structure, the air conditioner control means sets the operating output of the heat exchanger of the air conditioner and controls the heat exchanger to operate at the set operating output, while when heating, if the allowable indoor temperature is below the measured value of the return air temperature and the outside air load to be processed exceeds the expected outside air load of the structure, the air conditioner control means sets the operating output of the heat exchanger of the air conditioner and controls the heat exchanger to operate at the set operating output, so that air conditioning control can be performed that takes into account the effects of heat exchange between the structure and the underfloor space when cooling and heating.

[0069] In addition, according to the air conditioning control method of the present invention, there is provided an air conditioning control method for an air conditioning system that includes a structural body heat storage type radiant air conditioning device that radiates thermal energy stored in the structural body to the underfloor space above the structural body using a heat medium supplied to piping embedded in the structural body that constitutes the floor slab of the building into the underfloor space above the structural body, an air conditioner that generates conditioned air by heat exchanging fresh air taken in from outdoors using a heat exchanger while taking in return air from the indoor space, and an underfloor air conditioning device that blows the conditioned air supplied from the air conditioner to the underfloor space above into the indoor space, and the method includes an air conditioner control step that controls the operating output of the heat exchanger based on the heat flux from the structural body to the underfloor space, the indoor set temperature set in the indoor space, and the inlet air temperature of the heat exchanger. Therefore, in an air conditioning system that combines a structural body heat storage type radiant air conditioning system and an underfloor air conditioning system, air conditioning control can be performed that takes into account the influence of heat exchange between the structural body and the underfloor space.

[0070] In addition, another air conditioning control method according to the present invention includes a structure heat storage control step that controls the amount of heat medium supplied based on a comparison between the allowable surface temperature of the structure, which is set based on the indoor set temperature, and the measured value of the surface temperature of the structure, and the air conditioner control step controls the operating output of the heat exchanger based on a comparison between the allowable indoor temperature, which is set based on the indoor set temperature, and the measured value of the return air temperature, thereby enabling efficient air conditioning control.

[0071] Furthermore, according to another air conditioning control method of the present invention, the air conditioner control step, during cooling, if the allowable indoor temperature exceeds the measured value of the return air temperature and the outdoor air load to be processed exceeds the predicted outdoor air load of the building, sets the operating output of the heat exchanger of the air conditioner and controls the heat exchanger to operate at the set operating output, while during heating, if the allowable indoor temperature is below the measured value of the return air temperature and the outdoor air load to be processed exceeds the predicted outdoor air load of the building, sets the operating output of the heat exchanger of the air conditioner and controls the heat exchanger to operate at the set operating output, so that air conditioning control can be performed that takes into account the effects of heat exchange between the building and the underfloor space during cooling and heating.

[0072] The Sustainable Development Goals (SDGs) are 17 international goals adopted at the United Nations Summit in September 2015. The air conditioning system and air conditioning control method according to this embodiment can contribute to achieving one of the 17 SDGs, for example, goal 7, "Affordable and clean energy." [Industrial Applicability]

[0073] As described above, the air conditioning system and air conditioning control method of the present invention are useful for air conditioning systems that combine a building structure heat storage type radiant air conditioning system and an underfloor air conditioning system, and are particularly suitable for air conditioning control that takes into account the effects of heat exchange between the building structure and the underfloor space. [Explanation of symbols]

[0074] 10. Air Conditioning System 12 TABS (frame heat storage type radiant air conditioner) 14 Desiccant air conditioner (air conditioner) 16 Floor air conditioner 18 Control Device 18A Body heat storage control unit (body heat storage control means) 18B Air conditioner control unit (air conditioner control means) 20 Indoor space 22 Body 24 Piping 26 Underfloor space 52A Cooling coil (heat exchanger) 52B Heating coil (heat exchanger)

Claims

1. An air conditioning system comprising: a structural body heat storage type radiant air conditioning device that radiates heat energy stored in a structural body constituting a floor slab of a building to an underfloor space above the structural body by a heat medium supplied to piping embedded in the structural body; an air conditioner that generates conditioned air by heat exchange with outside air taken in from outdoors using a heat exchanger, while taking in return air from an indoor space; and a floor-blowout air conditioning device that blows the conditioned air supplied from the air conditioner to the underfloor space upward into the indoor space, An air conditioning system characterized by having an air conditioner control means that controls the operating output of the heat exchanger based on the heat flux from the building structure to the underfloor space, the indoor set temperature set in the indoor space, and the inlet air temperature of the heat exchanger.

2. The air conditioning system of claim 1, further comprising a structure heat storage control means for controlling the amount of heat medium supplied based on a comparison between the allowable surface temperature of the structure, which is set based on the indoor set temperature, and the measured value of the surface temperature of the structure, and the air conditioner control means for controlling the operating output of the heat exchanger based on a comparison between the allowable indoor temperature, which is set based on the indoor set temperature, and the measured value of the return air temperature.

3. The air conditioning system of claim 2, wherein the air conditioner control means, during cooling, sets the operating output of the heat exchanger of the air conditioner and controls the heat exchanger to operate at the set operating output when the allowable indoor temperature exceeds the measured value of the return air temperature and the outdoor air load to be treated exceeds the expected outdoor air load of the building, while during heating, when the allowable indoor temperature is below the measured value of the return air temperature and the outdoor air load to be treated exceeds the expected outdoor air load of the building, sets the operating output of the heat exchanger of the air conditioner and controls the heat exchanger to operate at the set operating output.

4. An air conditioning control method for an air conditioning system including a building frame heat storage type radiant air conditioning device that radiates heat energy stored in a building frame by a heat medium supplied to piping embedded in the building frame that constitutes a floor slab into an underfloor space above the building frame, an air conditioner that generates conditioned air by heat exchange with outside air taken in from outdoors using a heat exchanger, and that takes in return air from an indoor space, and an underfloor air-conditioning device that blows the conditioned air supplied from the air conditioner to the underfloor space above into the indoor space, An air conditioning control method characterized by having an air conditioner control step of controlling the operating output of the heat exchanger based on the heat flux from the building structure to the underfloor space, the indoor set temperature set in the indoor space, and the inlet air temperature of the heat exchanger.

5. The air conditioning control method according to claim 4, further comprising a structure heat storage control step of controlling the amount of heat medium supplied based on a comparison between the allowable surface temperature of the structure set based on the indoor set temperature and the measured value of the surface temperature of the structure, and the air conditioner control step of controlling the operating output of the heat exchanger based on a comparison between the allowable indoor temperature set based on the indoor set temperature and the measured value of the temperature of the return air.

6. 6. The air conditioning control method according to claim 5, wherein the air conditioner control step, during cooling, if the allowable indoor temperature exceeds the measured value of the return air temperature and the outdoor air load to be treated exceeds the predicted outdoor air load of the building, sets an operating output of the heat exchanger of the air conditioner and controls to operate the heat exchanger at the set operating output, while, during heating, if the allowable indoor temperature is below the measured value of the return air temperature and the outdoor air load to be treated exceeds the predicted outdoor air load of the building, sets an operating output of the heat exchanger of the air conditioner and controls to operate the heat exchanger at the set operating output.

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