Air conditioning control system and air conditioning control method

Abstract

To properly control the air conditioning in a passive displacement air conditioning system. [Solution] The air conditioning control system 10 is a system that controls a passive displacement air conditioning system in which air conditioning equipment is installed in an air conditioning space 130 separated from the space to be air-conditioned 120, and air flows in and out through an opening provided between the spaces. The system comprises an acquisition unit 11 that acquires control information including information on the airflow rate passing through the air conditioning equipment, and a control unit 12 that controls the air conditioning by the passive displacement air conditioning system based on the control information acquired by the acquisition unit 11.

Description

[Technical Field]

[0001] The present invention relates to an air conditioning control system and an air conditioning control method for controlling an air conditioning system. [Background technology]

[0002] Conventionally, it has been proposed to estimate the temperature distribution of a space to be air-conditioned using CFD analysis and to use the estimated results for air conditioning (see, for example, Patent Document 1). [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2021-99193 [Overview of the project] [Problems that the invention aims to solve]

[0004] Some air conditioning systems involve installing air conditioning equipment, such as air conditioning coils (e.g., cooling coils), in a separate space for air conditioning, and performing air conditioning by allowing air to flow in and out through an opening between the air-conditioned space and the air-conditioned space. Furthermore, some such air conditioning systems are passive displacement air conditioning systems that utilize natural circulation based on the temperature difference (density difference) of the air between the air-conditioned space and the air-conditioned space without using fans. Passive displacement air conditioning systems offer advantages such as noise reduction, energy saving, and draft reduction.

[0005] However, controlling the air conditioning in a passive displacement air conditioning system may not be appropriate if the control method is the same as that used for conventional air conditioning systems, as described above. For example, using the same control method as before may result in problems with the temporal control response.

[0006] The present invention has been made in view of the above, and aims to provide an air conditioning control system and an air conditioning control method that can appropriately control air conditioning in a passive displacement air conditioning system. [Means for solving the problem]

[0007] To achieve the above objective, the air conditioning control system according to the present invention is an air conditioning control system that controls a passive air conditioning system in which air conditioning equipment is installed in an air conditioning space separated from a space to be air-conditioned, and air flows in and out through an opening provided between the spaces, and comprises an acquisition means for acquiring control information including information relating to the airflow rate passing through the air conditioning equipment, and a control means for controlling air conditioning by the passive air conditioning system based on the control information acquired by the acquisition means.

[0008] In the air conditioning control system according to the present invention, air conditioning by a passive displacement air conditioning system is controlled based on control information including information on the airflow rate passing through the air conditioning equipment. According to the air conditioning control system according to the present invention, by considering the airflow rate in the control, air conditioning in a passive displacement air conditioning system can be appropriately controlled.

[0009] The acquisition means may include acquiring information related to airflow, such as information indicating the size of the opening and information indicating the relationship between the airflow and the size of the opening. With this configuration, information indicating airflow can be acquired appropriately and reliably, and as a result, air conditioning control in the passive displacement air conditioning system can be performed appropriately and reliably.

[0010] The opening is variable in size, and the control means may change the size of the opening. With this configuration, the air conditioning in the passive displacement air conditioning system can be appropriately controlled according to the control of the size of the opening.

[0011] The control means may control the air conditioning by the passive air conditioning system so that the temperatures at a plurality of different positions in the vertical direction in the space to be air-conditioned reach a preset target temperature. According to this configuration, control can be performed so that the temperatures at a plurality of different positions in the vertical direction are appropriate.

[0012] By the way, the present invention can be described not only as an invention of an air conditioning control system as described above, but also as an invention of an air conditioning control method as follows. These are only different in category, and are substantially the same invention, and exhibit the same operations and effects.

[0013] That is, the air conditioning control method according to the present invention is an air conditioning control method which is an operation method of an air conditioning control system for controlling a passive displacement air conditioning system in which air conditioning equipment is provided in an air conditioning space partitioned from the space to be air-conditioned, and air flows in and out through an opening provided between the spaces, the method including: an acquisition step of acquiring control information including information related to the air volume passing through the air conditioning equipment; and a control step of controlling the air conditioning by the passive displacement air conditioning system based on the control information acquired in the acquisition step.

Effect of the Invention

[0014] According to the present invention, the air conditioning in the passive displacement air conditioning system can be appropriately controlled.

Brief Description of the Drawings

[0015] [Figure 1] It is a diagram showing the configuration of an air conditioning control system according to an embodiment of the present invention. [Figure 2] It is a graph showing the relationship between the correction coefficient related to the air volume passing through the air conditioning coil and the area of the opening. [Figure 3] It is a flowchart showing an air conditioning control method which is a process executed by the air conditioning control system according to an embodiment of the present invention. [Figure 4] It is a graph showing the temporal change of the temperature in the space where air conditioning is performed by the passive air conditioning system. [Figure 5] A graph showing the temperature at each height from the floor of a space where air conditioning is performed by a passive air conditioning system.

Embodiments for Carrying Out the Invention

[0016] Hereinafter, embodiments of an air conditioning control system and an air conditioning control method according to the present invention will be described in detail with reference to the drawings. In the description of the drawings, the same reference numerals are assigned to the same elements, and redundant descriptions are omitted.

[0017] FIG. 1 shows an air conditioning control system 10 according to the present embodiment. The air conditioning control system 10 is a system that controls an air conditioning system. The air conditioning system to be controlled by the air conditioning control system 10 is a passive displacement air conditioning system. In the passive displacement air conditioning system, air conditioning equipment is provided in an air conditioning space partitioned from the space to be air conditioned, and air flows in and out through an opening provided between the spaces.

[0018] The space to be air conditioned is, for example, a part of a room in a building as follows. As schematically shown in FIG. 1, a room 100 is partitioned by a wall 110 and divided into an air conditioning target space 120 and an air conditioning space 130. The air conditioning target space 120 is, for example, a space that can be used by an occupant as shown in FIG. 1. In the air conditioning space 130, an air conditioning coil 200, which is air conditioning equipment, is positioned and fixedly provided. The air conditioning coil 200 is, for example, a cooling coil (chilled water coil). When a cooling coil is used as the air conditioning coil 200, the air conditioning performed is cooling. Note that the air conditioning equipment does not necessarily have to be the air conditioning coil 200, and any equipment used in a passive displacement air conditioning system may be used. Also, the air conditioning performed does not necessarily have to be cooling.

[0019] An opening is provided between the space to be air-conditioned 120 and the space for air conditioning 130. This opening is provided so that air can be input and output and circulated between the space to be air-conditioned 120 and the space for air conditioning 130. For example, as shown in Figure 1, an opening may be provided in at least a portion of the ceiling and floor of the wall 110 that separates the space to be air-conditioned 120 and the space for air conditioning 130.

[0020] Heat exchange occurs between the air circulating between the space to be air-conditioned 120 and the air conditioning space 130, and the air conditioning coil 200. For example, this air is cooled by the air conditioning coil 200. The cooled air enters the space to be air-conditioned 120 from the air conditioning space 130, thereby cooling the space to be air-conditioned 120. For example, as shown in Figure 1, in the space to be air-conditioned 120, the air is heated, generating buoyancy. Due to this buoyancy, the heated air in the space to be air-conditioned 120 is drawn from the space to be air-conditioned 120 to the air conditioning space 130 through an opening on the upper side (towards the ceiling of the room). In the air conditioning space 130, the air entering from above is cooled by the air conditioning coil 200 and moves downward, then is blown out into the space to be air-conditioned 120 through an opening on the lower side (towards the floor of the room).

[0021] Thus, passive displacement air conditioning systems do not have fans and perform air conditioning by utilizing natural circulation through temperature differences (density differences) in the air without using fans. The space in which a passive displacement air conditioning system is composed can be the same as conventional systems.

[0022] The air conditioning control system 10 is specifically a computer including hardware such as a CPU (Central Processing Unit) and memory. The various functions of the air conditioning control system 10, as described later, are performed by the operation of these components by programs, etc. The air conditioning control system 10 may be implemented by a single computer, or by a computer system consisting of multiple computers connected to each other by a network. The air conditioning control system 10 may have communication functions for acquiring information necessary for the control described below and for controlling the passive replacement air conditioning system.

[0023] The control performed by the air conditioning control system 10 is, for example, to set the temperature (room temperature) of the space 120 to be air-conditioned to a set temperature (control temperature). The air conditioning control system 10 controls the air conditioning coil 200. The air conditioning coil 200 is equipped with a valve that allows chilled water to pass through the coil. The amount of chilled water used for heat exchange that passes through the air conditioning coil 200, that is, the degree of cooling (air conditioning), depends on the opening of the valve. The opening of the valve can be controlled from the outside.

[0024] The air conditioning control system 10 controls the opening degree (%) of the valve of the air conditioning coil 200 as a control for the passive replacement air conditioning system. The air conditioning coil 200 is connected to the air conditioning control system 10 by wire or wireless connection and is capable of receiving control from the air conditioning control system 10. The passive replacement air conditioning system, including the air conditioning coil 200, can be the same as conventional systems.

[0025] Furthermore, the space used in the passive displacement air conditioning system and the passive displacement air conditioning system may be equipped with devices (e.g., sensors) for control by the air conditioning control system 10, as described later. The devices for control by the air conditioning control system 10, such as sensors, may be the same as those used in the past.

[0026] Next, the functions of the air conditioning control system 10 according to this embodiment will be described. As shown in Figure 1, the air conditioning control system 10 comprises an acquisition unit 11 and a control unit 12.

[0027] Control by the air conditioning control system 10 is performed, for example, by repeatedly determining the opening degree of the valve of the air conditioning coil 200 at regular time intervals (for example, 30 minutes) and setting it for the air conditioning coil 200. The functions of the air conditioning control system 10 shown below are functions for determining and controlling the opening degree of the valve of the air conditioning coil 200 at consecutive time steps within the above time intervals.

[0028] The acquisition unit 11 is an acquisition means for acquiring control information, including information about the airflow passing through the air conditioning equipment. The acquisition unit 11 may also acquire information related to airflow, such as information indicating the size of the opening and information indicating the relationship between the airflow and the size of the opening.

[0029] The control information acquired by the acquisition unit 11 is information used for control by the air conditioning control system 10. Control by the air conditioning control system 10 is performed taking into consideration the airflow rate (amount of air) (circulating airflow rate) passing through the air conditioning coil 200 in the air-conditioned space 130. The acquisition unit 11 acquires information related to the airflow rate as control information. The airflow rate is, for example, the volume Q [m³] of air passing through the air conditioning coil 200 per unit time. 3 The airflow rate is [ / h]. The airflow rate corresponds to the opening between the space to be air-conditioned 120 and the space for air conditioning 130. The acquisition unit 11 acquires information related to the airflow rate, including information indicating the size of the opening and information indicating the relationship between the airflow rate and the size of the opening.

[0030] Information indicating the size of the opening is, for example, the area A of the opening [m²]. 2This information indicates the area of ​​the opening. For example, the area A of the opening is the area when viewed from a direction perpendicular to the wall 110. Also, of multiple openings, usually only one opening has an area that affects the airflow. For example, as mentioned above, if there are two openings, one on the ceiling side and one on the floor side, the opening that affects the airflow is the one with the smaller area (the smaller of areas 140a and 140b in Figure 1). The information indicating the size of the opening relates to the opening with the smaller area that affects the airflow.

[0031] In room 100, a difference in air density occurs due to the temperature difference between the upper and lower parts of the room. The resulting pressure difference between the upper and lower parts acts as a driving force, generating convection due to buoyancy. Based on this pressure difference, it is theoretically possible to calculate the airflow rate passing through the air conditioning coil 200. The relationship between airflow rate and opening size shown below was discovered through the inventor's research and experiments, and allows for highly accurate calculation of airflow rate.

[0032] Information showing the relationship between airflow and opening size can be found, for example, the opening area A[m²]. 2 ] and airflow (pass-through airflow) Q [m 3 This is an expression that shows the relationship between / h]. An example of such an expression is the following:

number

[0033] The pressure difference ΔP is generated by the density difference based on the temperature difference between the air inside and outside the space 120 to be air-conditioned and the space 130 for air-conditioning at the height difference ΔH of the upper and lower openings between the space 120 to be air-conditioned and the space 130 for air-conditioning. This is the basic physical principle for promoting natural ventilation. ΔP [Pa] is expressed by the following formula based on the basic formula of the pressure difference due to the stack effect. ΔP = ρ0 × g × ΔH × (T_in - T_out) / T_in In the above formula, ρ0: air density in the space 130 for air-conditioning [kg / m 3 , g: gravitational acceleration (9.8 [m 2 / s]), ΔH: height difference of the upper and lower openings between the space 130 for air-conditioning and the space 120 to be air-conditioned [m], T_in: absolute temperature of the space 120 to be air-conditioned [K], T_out: absolute temperature of the space 130 for air-conditioning [K].

[0034] The air volume Q passing from the space 130 for air-conditioning to the space 120 to be air-conditioned through the opening p , and the air volume Q passing from the space 120 to be air-conditioned to the space 130 for air-conditioning through the opening p are, from the formula of temperature difference conversion, <00001​​​​​​​​​​​​​​ The correction factor c depends on the size of the opening (for example, the opening area A). Furthermore, the correction factor c depends on the space 130 used for air conditioning. For example, the correction factor c depends on the horizontal distance between wall 110 (i.e., the opening (air intake)) and the wall opposite wall 110 in the air conditioning space 130 (the horizontal distance 150 in the air conditioning space 130 in Figure 1). Figure 2 shows a graph of the relationship between the correction factor c, the opening area A, and the aforementioned distance. In the graph in Figure 2, the horizontal axis represents the opening area A, and the vertical axis represents the correction factor c. Also, graphs A and B represent different distances. The distance in A is longer than the distance in B.

[0037] As shown in Figure 2, the correction coefficient c decreases as the size of the opening increases. That is, as the size of the opening increases, the amount of air passing through the air conditioning coil 200 within the air conditioning space 130 decreases. Also, the correction coefficient c decreases as the above distance within the air conditioning space 130 increases. That is, as the above distance within the air conditioning space 130 increases, the amount of air passing through the air conditioning coil 200 within the air conditioning space 130 decreases.

[0038] The correction coefficient c is generated, for example, by taking measurements in advance on an air-conditioned space 130 in which an air conditioning coil 200 is installed.

[0039] The acquisition unit 11 acquires an equation showing the relationship between the opening area A and the airflow rate Q. For example, the acquisition unit 11 acquires the equation by reading information pre-stored in the air conditioning control system 10, or by accepting input from the user. The acquisition unit 11 also acquires information indicating the opening area A. The acquisition of information indicating the opening area A can be performed in the same way as the acquisition of the equation described above. Furthermore, if the opening area is controlled by the control unit 12 as described later, the acquisition unit 11 may acquire information indicating the opening area A from the control unit 12.

[0040] The acquisition unit 11 acquires information indicating the correction coefficient c. The acquisition of information indicating the correction coefficient c can be performed in the same manner as the acquisition of the above formula. Alternatively, the acquisition unit 11 may pre-store a relationship (for example, the relationship shown in the graph of Figure 2) for determining the correction coefficient c from the size of the opening and the horizontal distance of the air conditioning space 130, acquire information for determining the correction coefficient c (size of the opening and the horizontal distance of the air conditioning space 130), and determine the correction coefficient c from the acquired information and the relationship.

[0041] In the equation showing the relationship between the opening area A and the airflow rate Q, the flow coefficient α is a preset value (a value between 0.6 and 0.7, for example, 0.7). The acquisition unit 11 acquires information indicating the flow coefficient α. The air density ρ may vary depending on the air temperature in the air-conditioned space 130. The relationship between air density ρ and air temperature is a known relationship.

[0042] According to the information acquired by the acquisition unit 11, the relationship between the opening area A and the airflow rate Q is a function that shows the relationship between the air temperature and the airflow rate Q in the air-conditioned space 130. The acquisition unit 11 may also acquire other information related to airflow, as long as it can be used for control.

[0043] The acquisition unit 11 may acquire information other than the above-mentioned information related to airflow as control information. Such information may include, for example, information related to the passive displacement air conditioning system and information related to the environment inside and outside the space 120 to be air-conditioned (for example, temperature). Furthermore, such information may be information at the time of control (current time) (information on the state quantity at the current time). In addition, such information may be other than those mentioned above as long as it relates to the control of the air conditioning.

[0044] Specifically, the information in question indicates the temperature of the chilled water input to the air conditioning coil 200 (chilled water inlet temperature) at the time of control. It also includes weather data (e.g., outside temperature and humidity) at the time of control. Furthermore, it includes the temperature and humidity at pre-set locations (e.g., locations where sensors are installed) in the air-conditioned space 120 and the air-conditioned space 130. This information can be the same as that used in conventional air conditioning control, and the acquisition unit 11 can acquire this information in the same conventional way. The acquisition unit 11 may also acquire other information as control information other than the airflow information mentioned above. The acquisition unit 11 outputs the acquired control information to the control unit 12.

[0045] The control unit 12 is a control means that controls the air conditioning by the passive displacement air conditioning system based on the control information acquired by the acquisition unit 11. The control unit 12 may also control the air conditioning by the passive displacement air conditioning system so that the temperature at multiple different vertical positions in the space 120 to be air-conditioned reaches a preset target temperature.

[0046] The control unit 12 controls the air conditioning by the passive displacement air conditioning system, for example, as follows: The control unit 12 stores in advance rules for determining the content of the control and makes decisions according to those rules. The control unit 12 receives control information from the acquisition unit 11. The control unit 12 also acquires information indicating the set temperature of the space 120 to be air-conditioned. The set temperature is a pre-set target temperature. For example, the control unit 12 acquires information indicating the set temperature by accepting input operations from the user.

[0047] The control unit 12 determines the control content from the control information input from the acquisition unit 11 and the acquired information indicating the set temperature. As the control content, the control unit 12 determines the opening degree (%) of the valve of the air conditioning coil 200, as described above. Note that, if the control unit 12 is controlling a passive displacement air conditioning system, it may control something other than the opening degree (%) of the valve of the air conditioning coil 200.

[0048] The control unit 12 determines the control content, for example, by an optimization method. The determination by the optimization method is performed to optimize the value of a predetermined objective function, which is determined by the control content, while satisfying predetermined constraints. The value of the objective function may be based on the results of a simulation (future prediction) of what would happen if the control were performed according to the determined control content. The simulation may make predictions over multiple points in the future. For example, it may make predictions over 10 time steps of 30 minutes each (5 hours).

[0049] The objective function is, for example, the difference between the set temperature and the temperature at multiple different vertical locations within the space 120 to be air-conditioned. The vertical locations related to the temperature in the objective function are, for example, three locations at 0.1m, 0.6m, and 1.1m from the floor. This takes into account that ASHRAE Standard 55 stipulates that, when seated, the average temperature at the above three locations (heights) should be used for evaluation. The horizontal locations related to the temperature in the objective function are predetermined locations (for example, locations where occupants are assumed to be in the space 120 to be air-conditioned). There may be multiple such horizontal locations.

[0050] The value of the objective function is ∫|ave{0.1,0.6,1.1m room temperature}-set temperature|, which is the time- and position-integrated absolute value of the difference between the average temperature across three vertical directions ave{0.1,0.6,1.1m room temperature} and the set temperature. Since it is desirable for the above difference to be small, the value of this objective function is minimized during optimization.

[0051] In addition to the above, the objective function may also be the amount of heat generated from the air conditioning coil 200. The value of the objective function is the value obtained by integrating the amount of heat generated from the air conditioning coil 200 over time, which is ∫coil heat quantity. Since it is desirable for the amount of heat generated from the air conditioning coil 200 to be small, the value of this objective function is minimized during optimization. When the above objective function is used, the amount of heat generated from the air conditioning coil 200 is calculated in the simulation.

[0052] When using multiple objective functions, for example, if two objective functions are used, such as the difference between the temperature in the air-conditioned space 120 and the set temperature, and the amount of heat generated from the air conditioning coil 200, then optimization should be performed by weighting these objective functions. Since the two objective functions mentioned above are trade-offs, by adjusting the weighting of the two, it is possible to switch between operation that prioritizes comfort and operation that prioritizes energy saving, for example, according to the owner's wishes.

[0053] The constraints include, for example, that the temperature differences at multiple different vertical locations within the air-conditioned space 120 satisfy a predetermined condition. Specifically, at the same horizontal location and time, the difference between the room temperature at 0.1m from the floor and the room temperature at 1.1m from the floor must be less than a threshold (e.g., 3°C) (temperature difference between 0.1m and 1.1m room temperature < 3°C). This takes into account that ASHRAE Standard 55 stipulates that the temperature difference between the two locations (heights) mentioned above should be kept below 3°C to minimize discomfort caused by vertical temperature distribution.

[0054] The objective function and constraints related to temperature described above may reflect the thermal preferences of the occupants. This can further enhance comfort. However, the objective function and constraints do not necessarily have to be those described above; any set that allows for appropriate control is acceptable. Furthermore, constraints do not necessarily need to be set.

[0055] The control unit 12 determines the control content by performing optimization as follows. First, the control unit 12 provisionally assigns the valve opening degree of the air conditioning coil 200 to be optimized. For example, when making predictions for 10 steps as described above, the control unit 12 assigns the valve opening degree (M) at each step. t=1 M t=2 ,…,M t=10 Let's assume that M t=1 This is the valve opening at the time of control (t=1), and M t=2 This is the valve opening at the next time step (t=2), Mt=10 This represents the valve opening at step 10 (t=10). The provisional determination of the optimization target can be carried out in the same way as in conventional optimization methods. For example, the valve opening initially determined provisionally may be the opening that corresponds to the design flow rate, which is the flow rate assumed when the valve is designed.

[0056] The control unit 12 performs a simulation based on the control information input from the acquisition unit 11 and the set valve opening of the air conditioning coil 200 to calculate the airflow rate passing through the air conditioning coil 200, the temperature of the air blown out from the air-conditioned space 130 to the space to be air-conditioned 120 (outlet air temperature), and the temperature at a preset position in the air-conditioned space 120 (space temperature). The control unit 12 calculates the airflow rate, outlet air temperature, and space temperature at each time step.

[0057] In the space 120 to be air-conditioned, the locations where the temperature is calculated include the locations related to the temperature in the objective function and constraint conditions (for example, the three vertical locations at 0.1m, 0.6m, and 1.1m as described above). In the space 120 to be air-conditioned, the locations where the temperature is calculated include the locations where air is drawn from the space 120 to be air-conditioned into the air-conditioned space 130 (i.e., the locations of the openings where the air is drawn in). In other words, the spatial temperature includes the temperature of the air drawn from the space 120 to be air-conditioned into the air-conditioned space 130 (intake air temperature). For example, in the space 120 to be air-conditioned, the locations where the temperature is calculated are each location when the space 120 to be air-conditioned is divided into a grid (mesh).

[0058] The simulation uses a model that includes a function (relationship) for calculating the airflow rate passing through the air conditioning coil 200, a function (relationship) for calculating the outlet air temperature, and a function (relationship) for calculating the ambient temperature.

[0059] The function for calculating the airflow rate passing through the air conditioning coil 200 is the area of ​​the opening A [m²], which is included in the control information acquired by the acquisition unit 11. 2 ] and airflow Q[m 3This is an equation that shows the relationship between [ / h]. ρ and ΔP in the above equation correspond to the outlet air temperature and the intake air temperature. Therefore, this function shows the relationship between the airflow rate and the outlet air temperature and the intake air temperature. That is, this relationship is expressed as a function of airflow rate = f(outlet air temperature, intake air temperature). The control unit 12 stores in advance the relationship between ρ and ΔP and the outlet air temperature and the intake air temperature (the equation for calculating ρ and ΔP from the outlet air temperature and the intake air temperature). This relationship is well known.

[0060] The control unit 12 stores in advance a function for calculating the discharge air temperature and a function for calculating the ambient temperature. The function for calculating the discharge air temperature shows the relationship between the discharge air temperature, the chilled water inlet temperature, the amount of water input to the air conditioning coil 200, the intake air temperature, and the airflow rate passing through the air conditioning coil 200. That is, this relationship is expressed as a function of discharge air temperature = g(chilled water inlet temperature, water amount, intake air temperature, airflow rate). A known relationship (for example, the one shown in Yamaguchi, Yoshida, Niwa, Watanabe, Miyata, Oda, Shioya, Experiments on Cooling Coil Characteristics and Verification of Model Accuracy for Commissioning, Transactions of the Society of Heating, Air-Conditioning and Sanitary Engineers of Japan, 2009, Vol. 34, No. 143, pp. 61-70 (Non-Patent Literature 1)) may be used. The amount of water mentioned above corresponds to the valve opening degree set by the control unit 12. The control unit 12 has pre-stored the relationship between the water volume and the valve opening (the formula for calculating the water volume from the valve opening).

[0061] The function for calculating ambient temperature shows the relationship between ambient temperature, the temperature of the discharged air, the airflow rate passing through the air conditioning coil 200, and meteorological data. That is, the relationship is expressed as the function ambient temperature = h(discharged air temperature, airflow rate, meteorological data). A known relationship (for example, the one shown in Togawa, Sato, Arai, Miura, Study on Air Conditioning and Thermal Environment Planning Methods for Large Spaces, Part 1, Prediction Model of Vertical Temperature Distribution in Large Spaces, Journal of Architecture and Planning, Architectural Institute of Japan, No. 427, pp. 9-19, September 1991 (Non-Patent Literature 2)) may be used.

[0062] Simulations to calculate airflow, outlet air temperature, and ambient temperature based on the above relationship can be performed in the same manner as before. In the simulation for each time step, the conditions at the previous time step (for example, the ambient temperature at the previous time step) may be used.

[0063] Furthermore, the simulation may use temperature data acquired by sensors at pre-set positions in the space 120 to be air-conditioned at the time of control (for example, a position at a height of 1.1m from the floor and the position of the upper opening, which are related to the objective function). In addition, the relationships used in the simulation may include information other than that mentioned above (for example, humidity in the space 120 to be air-conditioned and the air-conditioning space 130, and data on heat-generating elements in the space 120 to be air-conditioned). In this case, this information can be acquired as control information by the acquisition unit 11 or calculated in the simulation, as in conventional methods. Both of these can be done by conventional methods.

[0064] The control unit 12 evaluates the objective function and constraints from the simulation results. The control unit 12 inputs the values ​​obtained from the simulation results into a pre-stored objective function to calculate the value of the objective function. For example, if the objective function is the difference between the temperature in the space 120 to be air-conditioned and the set temperature, the control unit 12 calculates the value of the objective function from the space temperature. Alternatively, if the objective function is the amount of heat generated from the air conditioning coil 200, the control unit 12 calculates the amount of heat generated from the air conditioning coil 200 from the simulation results (e.g., the outlet air temperature and the intake air temperature) and calculates the value of the objective function. The calculation of the amount of heat generated from the air conditioning coil 200 can be done using conventional methods.

[0065] The control unit 12 determines, based on the calculated value of the objective function, whether the given valve opening is optimized. This determination can be made using conventional optimization methods. For example, this determination can be made by determining whether the repeatedly calculated value of the objective function has converged.

[0066] The control unit 12 determines whether the simulation result satisfies the pre-stored constraint equations. If the simulation result does not satisfy the pre-stored constraint equations, the control unit 12 does not allow the provisionally given valve opening to be used as the control to determine the valve. If the simulation result satisfies the pre-stored constraint equations, the control unit 12 allows the provisionally given valve opening to be used as the control to determine the valve.

[0067] If, as a result of evaluating the objective function and constraints, it is determined that the given valve opening is not optimized, that is, the control content cannot be determined, the control unit 12 will again provide a provisional valve opening for the air conditioning coil 200 to be optimized and perform the simulation in the same manner as above, and evaluate the objective function and constraints from the simulation results. The setting of the valve opening for the air conditioning coil 200 again can be done using conventional optimization methods.

[0068] If, as a result of evaluating the objective function and constraints, the control unit 12 determines that the provisionally given valve opening is optimized, that is, that the control content can be determined, the control unit 12 determines the provisionally given valve opening as the control content. Note that the control content to be determined is the valve opening at the time the control is performed (t=1), so only the provisionally given valve opening at that time is determined as the control content.

[0069] The control unit 12 controls the air conditioning by the passive displacement air conditioning system according to the determined control content. Specifically, the control unit 12 sets the opening degree of the valve of the air conditioning coil 200 to the determined opening degree.

[0070] In the example described above, the control unit 12 determined the control content using an optimization method. However, the control unit 12 may determine the control content using a method other than optimization. For example, the control unit 12 may determine the control content using a reinforcement learning method. An example of this case is described below.

[0071] The control unit 12 stores a control policy for determining the content of the control. The control policy is used to determine the reinforcement learning operation variable (Action) from the reinforcement learning state variable (State). The reinforcement learning operation variable corresponds to the content of the control to be determined, and is the opening degree (%) of the valve of the air conditioning coil 200 at the time of control.

[0072] The state variables for reinforcement learning are, for example, the chilled water inlet temperature at the time of control, weather data, the temperature at a preset location in the space 120 to be air-conditioned (ambient temperature), and data on heat-generating elements in the space 120 to be air-conditioned. The state variables for reinforcement learning are included in the control information acquired by the acquisition unit 11. The format of the control policy may be the same as that of conventional reinforcement learning control policies. For example, the format of the control policy may be a table showing the correspondence between the state variables for reinforcement learning (input) and the operational variables for reinforcement learning (output).

[0073] Based on the stored control policy, the control unit 12 derives the content of the control, which is the operational variable for reinforcement learning, from the reinforcement learning state quantities included in the control information acquired by the acquisition unit 11. The control unit 12 also evaluates the reward for the derived content of the control.

[0074] The control unit 12 stores rules for evaluating rewards in advance and evaluates rewards according to these rules. The rules for evaluating rewards are similar to the objective function and constraints in the optimization method described above, and are also based on future prediction results.

[0075] Based on the derived control content, the control unit 12 performs a simulation similar to the optimization method described above to calculate the airflow rate passing through the air conditioning coil 200, the temperature of the air blown out from the air-conditioned space 130 to the air-conditioned space 120 (outlet air temperature), and the temperature at a preset location in the air-conditioned space 120 (space temperature). In this case, the derived control content is considered to be the provisionally determined control content in the optimization method described above. In this case, since the derived control content is only the valve opening of the air conditioning coil 200 at the time of control, calculation (prediction) only needs to be performed for the next time step. As in the example described above, the control unit 12 uses the information related to the airflow rate passing through the air conditioning equipment input from the acquisition unit 11.

[0076] The control unit 12 evaluates the reward for the determined control content based on the simulation results. The control unit 12 updates (learns) the control policy based on the evaluation. The evaluation of the reward and the updating of the control policy can be performed in the same way as in conventional reinforcement learning methods. The derivation of the control content based on the control policy and the updating of the control policy may be repeated in one time step.

[0077] The control unit 12 controls the air conditioning by the passive replacement air conditioning system based on the derived control content. For example, the control unit 12 controls the air conditioning by the passive replacement air conditioning system based on the control content derived by the control policy that has been updated at the time of control. The control based on the determined control content can be performed in the same manner as in the above case. The control unit 12 repeats the above process at each time step.

[0078] Furthermore, the state variables used as instrumental variables in reinforcement learning do not necessarily have to be measured values; they may be estimated values ​​(for example, those obtained from the simulation results described above). However, using measured values ​​as the state variables in reinforcement learning can improve the accuracy of reward calculation. For example, at a minimum, measured values ​​should be used for the cold water inlet temperature and weather data as described above.

[0079] Furthermore, the models used in the simulation may also be used for pre-training control policies. This can improve the accuracy of the initial control policies and shorten the learning period during actual operation.

[0080] As described above, by performing reinforcement learning based on simulation, rewards can be evaluated without using measured values. Therefore, sensors and other equipment used to measure and evaluate rewards are unnecessary. In other words, performing simulations using a model contributes to reducing measurement costs.

[0081] In the example above, the size of the opening between the space to be air-conditioned 120 and the space for air conditioning 130 was assumed to be fixed, but the size of the opening may be variable. In this case, the control unit 12 may change the size of the opening.

[0082] For example, the opening has a louver-like structure and its area is adjustable. By changing the size of the opening, the amount of air passing through the air conditioning coil 200 can be changed. Only one of several openings needs to have an adjustable area. As mentioned above, of the two openings on the ceiling and floor sides, the opening with the smaller area is the one that affects the airflow. Therefore, the opening with an adjustable area should have a smaller area than the other openings (even when set to its maximum area).

[0083] In this case, the opening has a configuration that allows its area to be changed by receiving control from the air conditioning control system 10. When controlling the size of the opening, the control unit 12 can make the determination in the same manner as above, including the size of the opening in the content of the control to be determined. When changing the size of the opening, the correction coefficient c is set to a value corresponding to the size of the opening.

[0084] By appropriately changing the size of the opening, it becomes possible to control the air conditioning effectively, for example, to achieve faster temperature response.

[0085] The following configuration may be adopted when the air conditioning control system 10 controls the passive displacement air conditioning system. In a passive displacement air conditioning system, it is usually necessary to introduce outside air separately. At this time, by blowing outside air (raw outside air or air treated by an air handling unit) toward the air conditioning coil 200 of the passive displacement air conditioning system, the circulating air volume of the passive displacement air conditioning system can be controlled more actively. This method can increase the air conditioning capacity of the passive displacement air conditioning system.

[0086] Similarly, by combining a passive displacement air conditioning system with a ceiling fan installed in the air-conditioned space 120, forced air circulation can be created, increasing the air conditioning capacity. Because occupants feel cool due to the airflow from the ceiling fan, the set temperature in the room can be set 1 to 3°C higher than usual. Therefore, energy-saving operation is possible. In addition, by utilizing the airflow, the set temperature can be reached more quickly than with a normal air conditioning system, and the temperature in the air-conditioned space 120 can be kept uniform. Furthermore, by utilizing the airflow, contaminants generated from the human body can be quickly removed, thus contributing to a reduction in the risk of infection. The rotation speed of the ceiling fan may be adjusted according to the preference of the occupants.

[0087] The passive displacement air conditioning system is basically for cooling only, but it can also be used for heating when combined with a ceiling fan. The ceiling fan is operated in an upward flow mode. During cooling, the upward flow caused by the heat load generated from the room and the direction of the airflow from the ceiling fan are the same, so cooling can be done efficiently. During heating, the heat accumulated near the ceiling can be diffused by the airflow, so heating can be done efficiently. When a ceiling fan is used, the amount of air passing through the air conditioning coil 200 in the air-conditioned space 130 is predominantly due to the ceiling fan. Therefore, the formula or the value of the airflow itself related to the amount of air passing through the air conditioning coil 200 is not the one described above, but rather one prepared and used for when a ceiling fan is used. The above describes the functions of the air conditioning control system 10 according to this embodiment.

[0088] Next, using the flowchart in Figure 3, the air conditioning control method, which is a process (operation method performed by the air conditioning control system 10) executed by the air conditioning control system 10 according to this embodiment, will be explained. This process is repeated at each time step. In this process, the acquisition unit 11 acquires control information used to control the passive replacement air conditioning system (S01, acquisition step). The acquired control information includes information relating to the airflow rate passing through the air conditioning coil 200, which is an air conditioning device provided in the passive replacement air conditioning system (for example, information indicating the size of the opening described above, and information indicating the relationship between the airflow rate and the size of the opening).

[0089] Next, the control unit 12 controls the air conditioning by the passive replacement air conditioning system based on the control information acquired by the acquisition unit 11. This control is performed, for example, by an optimization method as follows: First, the control content (for example, the opening degree of the valve of the air conditioning coil 200) is provisionally set (S02, control step). Next, a simulation is performed based on the provisionally set control content to calculate the airflow rate passing through the air conditioning coil 200, the temperature of the air blown out from the air-conditioned space 130 to the air-conditioned space 120 (outlet air temperature), and the temperature at a preset position in the air-conditioned space 120 (space temperature) (S03, control step). Next, the objective function and constraints are evaluated from the simulation results (S04, control step).

[0090] Next, based on the evaluation of the objective function and constraints, it is determined whether or not the control content can be determined (S05, control step). If it is determined that the control content cannot be determined, a provisional setting of the control content is made again, and the process up to the above determination according to the provisional setting is repeated (S02~S05).

[0091] In the above determination (S05), if it is determined that the content of the control can be determined, the provisionally set content of the control is determined as the content of the control to be implemented (S06, control step). Subsequently, the air conditioning by the passive displacement air conditioning system is controlled according to the determined content of the control (S07, control step). For example, the opening degree of the valve of the air conditioning coil 200 is set to the determined value. The above is the air conditioning control method according to this embodiment.

[0092] In the air conditioning control method described using the flowchart in Figure 3, the control unit 12 determines the content of the control using an optimization method. However, the control unit 12 does not necessarily have to determine the content of the control using an optimization method; it can be done based on the control information acquired by the acquisition unit 11.

[0093] In this embodiment, air conditioning by a passive displacement air conditioning system is controlled based on control information including information regarding the airflow rate passing through an air conditioning coil 200, which is an air conditioning device. According to this embodiment, by considering the airflow rate in the control, air conditioning in the passive displacement air conditioning system can be controlled appropriately. For example, the temporal control response can be improved. That is, the start-up of the air conditioning can be made faster. Furthermore, appropriate air conditioning control can be performed even in an indoor environment. In addition, overcooling can be prevented.

[0094] Furthermore, the air conditioning equipment does not necessarily have to be an air conditioning coil 200; any equipment that can affect the air conditioning according to the airflow is acceptable.

[0095] As in this embodiment, the acquisition unit 11 may acquire information indicating the size of the opening and information indicating the relationship between the airflow and the size of the opening as information related to the airflow. With this configuration, information indicating the airflow can be acquired appropriately and reliably, and as a result, the air conditioning in the passive displacement air conditioning system can be controlled appropriately and reliably. However, the information related to the airflow does not necessarily have to be as described above, and any information that can be used to control the air conditioning in the passive displacement air conditioning system is acceptable.

[0096] The opening is variable in size, and the control unit 12 may change the size of the opening. With this configuration, the air conditioning in the passive displacement air conditioning system can be appropriately controlled according to the control of the size of the opening. However, changing the size of the opening is not necessarily required.

[0097] The control unit 12 may control the air conditioning by the passive air conditioning system so that the temperature at multiple different vertical locations in the space to be air-conditioned reaches a preset target temperature. With this configuration, it is possible to control the temperature at multiple different vertical locations to be appropriate. For example, the vertical temperature distribution in the living area of ​​a room can be controlled to a comfortable range. However, the control of air conditioning in the passive displacement air conditioning system does not have to be for the above purpose. For example, as described above, it may be for the purpose of minimizing the amount of heat generated from the air conditioning coil 200.

[0098] Next, an example of the control results according to this embodiment is shown. Figure 4 shows the time change of temperature in a space where air conditioning is performed by the passive air conditioning system. The upper graph is the graph when control according to this embodiment is not performed, and the lower graph is the graph when control according to this embodiment is performed. The horizontal axis of the graph is the time of day, and the vertical axis of the graph is the temperature of the space. The graph shows the case when air conditioning is performed by the passive air conditioning system during a preset control time period of one day.

[0099] As shown in the graph in Figure 4, the time it takes for the ambient temperature to reach the set temperature is shorter when the control according to this embodiment is implemented compared to when the control according to this embodiment is not implemented. Thus, good temporal control responsiveness is achieved in this embodiment.

[0100] Figure 5 shows the temperature at different heights from the floor in a space where air conditioning is performed by a passive air conditioning system. The upper graph shows the temperature when control according to this embodiment is not performed, and the lower graph shows the temperature when control according to this embodiment is performed. The horizontal axis of the graph represents the temperature of the space at different heights from the floor, and the vertical axis represents the height from the floor. The graph shows the temperature at different time intervals from the start of control (start of control (0), 30 minutes later (30 min), 1 hour later (1 h), and 5 hours later (5 h)).

[0101] As shown in the graph in Figure 5, when the control according to this embodiment is implemented, the temperature variation in the height direction and the variation over time are smaller compared to when the control according to this embodiment is not implemented. Thus, in this embodiment, appropriate control is achieved in terms of temperature variation in the height direction and the variation over time.

[0102] The air conditioning control system and air conditioning control method of this disclosure have the following configuration. [1] An air conditioning control system that controls a passive displacement air conditioning system in which air conditioning equipment is installed in an air conditioning space separated from the space to be air-conditioned, and air flows in and out through an opening provided between the spaces, An acquisition means for acquiring control information including information relating to the airflow rate passing through the aforementioned air conditioning equipment, A control means for controlling the air conditioning by the passive replacement air conditioning system based on the control information acquired by the acquisition means, An air conditioning control system equipped with the following features. [2] The air conditioning control system according to [1], wherein the acquisition means acquires information relating to the airflow, including information indicating the size of the opening and information indicating the relationship between the airflow and the size of the opening. [3] The opening is of variable size, The control means is an air conditioning control system according to [1] or [2] which changes the size of the opening. [4] The control means controls the air conditioning by the passive displacement air conditioning system so that the temperature at multiple different vertical positions in the space to be air-conditioned reaches a preset target temperature, as described in any of [1] to [3]. [5] An air conditioning control method which is a method for operating an air conditioning control system that controls a passive displacement air conditioning system in which air conditioning equipment is installed in an air conditioning space separated from the space to be air-conditioned, and air flows in and out through an opening provided between the spaces, An acquisition step to acquire control information including information relating to the airflow rate passing through the aforementioned air conditioning equipment, A control step in which the air conditioning by the passive replacement air conditioning system is controlled based on the control information acquired in the acquisition step, An air conditioning control method including [Explanation of symbols]

[0103] 10...Air conditioning control system, 11...Acquisition unit, 12...Control unit, 200...Air conditioning coil.

Claims

1. An air conditioning control system that controls a passive displacement air conditioning system in which air conditioning equipment is installed in an air conditioning space separated from the space to be air-conditioned, and air flows in and out through an opening provided between the two spaces, An acquisition means for acquiring control information including information relating to the airflow rate passing through the aforementioned air conditioning equipment, A control means for controlling the air conditioning by the passive replacement air conditioning system based on the control information acquired by the acquisition means, Equipped with, The acquisition means is an air conditioning control system that acquires information relating to the airflow, including information indicating the size of the opening and information indicating the relationship between the airflow and the size of the opening.

2. The opening is variable in size, The control means is an air conditioning control system according to claim 1, which changes the size of the opening.

3. An air conditioning control method is an air conditioning control system that controls a passive displacement air conditioning system in which air conditioning equipment is installed in an air conditioning space separated from the space to be air-conditioned, and air flows in and out through an opening provided between the two spaces, An acquisition step to acquire control information including information relating to the airflow rate passing through the aforementioned air conditioning equipment, A control step in which the air conditioning by the passive replacement air conditioning system is controlled based on the control information acquired in the acquisition step, Includes, An air conditioning control method that, in the acquisition step, acquires information relating to the airflow, including information indicating the size of the opening and information indicating the relationship between the airflow and the size of the opening.

Images