Air conditioning system and control method

Abstract

The present invention provides an air conditioning system and control method that can reduce the energy consumption of air conditioners in specific areas when users are absent. [Solution] The air conditioning system is configured to apply localized air conditioning that adjusts the temperature and ventilation rate in multiple areas within a building. The air conditioning system includes a controller that predicts a first power consumption by an air conditioner when it is stopped operating in a specific area where users are expected to be absent, and a second power consumption by an air conditioner when it is operated in a specific area where users are expected to be absent, and stops the operation of the air conditioner in the area where users will be absent if the first power consumption is less than the second power consumption.

Description

Technical Field

[0001] The present invention relates to an air conditioning system and a control method.

Background Art

[0002] Against the backdrop of climate warming, there is a demand for further improving the energy efficiency of air conditioning systems. It is possible to reduce the energy consumption of air conditioners by replacing the overall air conditioning in conventional health and air conditioning (personal-targeted air conditioning) with localized air conditioning.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, with localized air conditioning, there have been cases where energy consumption does not decrease even if the operation of the air conditioner in a specific area where no user is present is stopped.

[0005] The present invention has been made in view of such actual circumstances, and an object of the present invention is to provide an air conditioning system and a control method that can reduce the energy consumption of an air conditioner in a specific area where no user is present.

Means for Solving the Problems

[0006] (1) The present invention has been made to solve the above problems, and one aspect of the air conditioning system of the present invention is applicable to local air conditioning that adjusts the temperature and ventilation rate of multiple areas in a building. The air conditioning system is an air conditioning system that includes a controller that predicts a first power consumption by an air conditioner when the operation of the air conditioner in a specific area where users are expected to be absent is stopped, and a second power consumption by the air conditioner when the air conditioner in the specific area where users are expected to be absent is operated, and stops the operation of the air conditioner in the area where users will be absent when the first power consumption is less than the second power consumption. (2) In the above air conditioning system, the controller estimates the power consumption of the air conditioner for each of the following periods: the period of absence during which the user of the specific area is expected to be absent, and the period of occupancy after the absence period. (3) In the above air conditioning system, the controller estimates the total power consumption consumed by the air conditioner during the absence period and the occupancy period using the first power consumption during the absence period and the second power consumption during the occupancy period. (4) In the above air conditioning system, the controller compares the first power consumption and the second power consumption using the total power consumption. (5) In the above air conditioning system, the controller calculates the indoor heat load Q for each of the multiple areas, including the specific area, and creates a user allocation plan that prioritizes assigning users to areas with a small indoor heat load Q relative to the number of people in each area, and calculates the power consumption of each area based on the user allocation plan. (6) One aspect of the control method for an air conditioning system of the present invention is a control method for an air conditioning system to which local air conditioning can be applied to adjust the temperature and ventilation rate of multiple areas in a building, and the control method includes predicting a first energy efficiency when the operation of an air conditioner in a specific area where no users are present is stopped, and a second energy efficiency when the air conditioner in the specific area where no users are present is operated, and stopping the operation of the air conditioner in the area where no users are present when it is estimated that the first energy efficiency will be higher than the second energy efficiency. [Effects of the Invention]

[0007] According to the present invention, it is possible to reduce the energy consumption of air conditioners in specific areas where users are absent. [Brief explanation of the drawing]

[0008] [Figure 1A] This is a diagram illustrating an air conditioning system 1 according to an embodiment. [Figure 1B] This is a diagram showing the configuration of the air conditioning system 1 according to the embodiment. [Figure 2A] This diagram illustrates the usage status of each area before the application of the energy reduction control of the embodiment. [Figure 2B] This diagram illustrates the usage status of each area after applying the energy reduction control of the embodiment. [Figure 3A] This figure shows an example of a model for calculating the estimated heat load in the embodiment. [Figure 3B] This figure shows an example of the calculation results for the estimated heat load in the embodiment. [Figure 4] This diagram illustrates the relationship between the usage patterns of each area in the embodiment and power consumption. [Figure 5] This is a flowchart of the process applied to the air conditioning control of the embodiment. [Figure 6] This graph shows the relationship between the PMV index and the PPD index in the embodiment. [Figure 7]This is a diagram for explaining the relationship between control of an air conditioner or the like and power consumption when in the absence state of the embodiment. [Figure 8] This is a flowchart of processing related to control of the air conditioner when in the absence state of the embodiment. [Modes for Carrying Out the Invention]

[0009] Hereinafter, an air conditioning system according to an embodiment of the present invention will be described based on the accompanying drawings.

[0010] FIG. 1A is a diagram for explaining an air conditioning system 1 according to the embodiment.

[0011] A case where the air conditioning system 1 is applied to health air conditioning control of a building will be described. The floor of the building exemplified here is divided into a plurality of areas by area boundaries. Each area can be provided with local air conditioning capable of individually adjusting the temperature and ventilation volume of the area, and local lighting capable of individually adjusting illuminance. Note that, to simplify the description of the embodiment, it is assumed that the area boundaries of the present embodiment have partitions such as walls or partitions, which restrict the flow of air between areas.

[0012] FIG. 1B is a configuration diagram of the air conditioning system 1 of the embodiment. The air conditioning system 1 includes air conditioners 11, 12, 13, and a controller 20. The air conditioners 11, 12, 13 are so-called packaged air conditioners capable of local air conditioning. The air conditioners 11, 12, 13 are respectively installed on ceilings or the like in areas r1, r2, r3. The air conditioners 11, 12, 13 adjust the indoor temperature, supply air volume, and ventilation volume of the area where they are arranged, under the control of the controller 20. In the following description, when the areas r1, r2, r3 are described without distinction, they may simply be referred to as the respective areas.

[0013] The controller 20 controls the air conditioners 11, 12, 13. Under the control of the controller 20, healthy air conditioning is provided for each area. The controller 20 further controls the air conditioners 11, 12, and 13 to reduce power consumption.

[0014] It should be noted that each area is respectively provided with the lamps 31, 32, 33 of the lighting equipment. The lamps 31, 32, 33 are collectively referred to as the respective lamps. Each of the lamps can be individually switched on and off, as well as adjusted in illuminance, adjusted in color rendering properties, and the like, under the control of the lighting equipment control device 30 (denoted as "lighting control" in the drawing). The lighting equipment control device 30 receives notifications from switches, remote controllers, and terminal devices (all not shown) provided in each area, and individually controls the lamp in each area according to the request of the operating user. Further, the lighting equipment control device 30 receives control from the controller 20 to individually control the lamp in each area. Hereinafter, details of the control by the controller 20 will be described in order.

[0015] Next, the energy reduction control of the embodiment will be described with reference to FIG. 2A and FIG. 2B. FIG. 2A is a diagram for explaining the usage status of each area before the application of the energy reduction control of the embodiment. FIG. 2B is a diagram for explaining the usage status of each area after the application of the energy reduction control of the embodiment.

[0016] (Before application of energy reduction control) FIG. 2A shows a state where users are dispersed in each area at a stage before the energy reduction control is applied. In such a situation, it is necessary to continue the operation of the healthy air conditioning in each area. (After application of energy reduction control) FIG. 2B shows a state where users come to use a specific area after the energy reduction control is applied. In such a situation, it is possible to continue or stop the operation of the healthy air conditioning in each area according to the presence or absence of users.

[0017] Next, the calculation of the estimated heat load in the embodiment will be explained with reference to Figures 3A and 3B. Figure 3A shows an example of a model for calculating the estimated heat load in the embodiment. Figure 3B shows an example of the calculation results for the estimated heat load in the embodiment.

[0018] The power consumption of an air conditioner varies depending on the location and size of the area, the number of people in the room, and the usage status of other equipment (devices) besides the air conditioner. Therefore, the power consumption of the air conditioner (air conditioning energy consumption) is estimated using the relationship between the designated heat load of the target area and the COP of the air conditioner in the target area. This relationship is shown in equation (1) below. Replace "air conditioning energy consumption" in equation (1) with the power consumption of the air conditioner.

[0019] Air conditioning energy consumption = Estimated heat load / (Air conditioner COP) ... (1)

[0020] As shown in Figure 3A, a wall W12 is provided between area r1 and area r2. A window W1E is provided between area r1 and the exterior of the building. Area r1 and area r2 have an upper floor and a lower floor.

[0021] Let θr1 be the room temperature in area r1, θr2 be the room temperature in area r2, and θa be the outside air temperature. Let θr3 be the room temperature on the floor above area r1, and θr4 be the room temperature on the floor below area r1. The indoor heat generated in area r1 is denoted as Hr.

[0022] As shown in Figure 3B, the indoor heat generation parameters in area r1 include "solar radiation load on glass surfaces," "lighting load," "human body load," "equipment load," and "outside air load." These parameters are examples of those that have a relatively large impact on the analysis of heat load. Figure 3B shows representative approximation formulas that can be used for the analysis of each item. You are not limited to these items and approximation formulas; you may add or delete items and modify formulas as appropriate.

[0023] "Solar radiation load on the glass surface" is the energy expected to pass through the glass surface from the outside to the inside of area r1. The degree to which "solar radiation load on the glass surface" is affected varies depending on the sunlight conditions of the day and the time of day being analyzed. It is recommended to switch the value of the coefficient (shading coefficient) applied to the approximation formula. "Lighting load" refers to the energy (thermal energy) emitted from lighting fixtures when they are switched on within area r1. It varies depending on the lighting usage. "Human load" is the energy emitted by people present in area r1. It changes depending on the number of people in area r1. "Equipment load" refers to the energy emitted from equipment used within area r1. "Outside air load" is the energy that depends on the amount of outside air taken into area r1 for ventilation. Since the amount of ventilation changes depending on the number of people in area r1, the "outside air load" also changes depending on the number of people in the room. A detailed example of this formula is shown in the figure.

[0024] Summarizing the above, we derive the relationship shown in equations (2) and (3). Equation (3) is a rewrite of equation (2).

[0025] Estimated heat load = Heat load passing through the 6 walls of the room + Heat generated inside the room ... (2)

[0026] Σθ = Σθr + Hr ···(3)

[0027] In equation (3) above, "Σθ" is the estimated heat load of the area under analysis, and "Σθr" is the heat load passing through the six walls of the room in the area under analysis. For "Hr", the estimated value of the indoor heat generation of the area under analysis is applied.

[0028] The above "heat load through the wall" is approximated for each of the four directions of walls, floors, and ceilings using the following equation (4).

[0029] Heat load through a wall = Heat load coefficient × Wall area × (Room temperature - adjacent room temperature or outside temperature) ...(4)

[0030] In equation (4) above, "room temperature" refers to the room temperature of the area being analyzed, and "adjacent room temperature" refers to the room temperature of the area adjacent to the area being analyzed. The "heat load coefficient" is a predetermined value determined by the structure and material of the wall.

[0031] Next, referring to Figure 4, we will explain the relationship between the usage patterns and power consumption of each area. Figure 4 is a diagram illustrating the relationship between the usage patterns and power consumption of each area in the embodiment.

[0032] The table shown in Figure 4 shows the calculation conditions using the number of people in each area, the air conditioning temperature setting, and the lighting intensity as variables, and the calculation results show the power consumption for each area and the total power consumption. Each row in this list corresponds to one condition.

[0033] The top row of this table shows an example where the number of people in each area is 3, 2, and 1, the air conditioning temperature is set to 24°C in all areas, and the lighting intensity is set to medium, medium, and low. In this case, the predicted power consumption for each area is 9kW, 6kW, and 5kW, respectively, and the sum of these is 20kW.

[0034] The same applies if it is shown on any other level. Furthermore, areas marked with "0" in the "Number of People" column indicate that there are no occupants in the room. In addition, ventilation is also stopped in these cases. The "-" in the air conditioning temperature column indicates that the air conditioners in that area are stopped.

[0035] While the total number of people in each row is consistently 6, a comparison of the total power consumption in each row reveals that the fourth row from the top has a total value of "16kW". This fourth row represents the lowest value among the six conditions shown in this table.

[0036] The difference from the other cases was that the six people were led to one area, the air conditioning in the two unoccupied areas was turned off, and the lights were switched off. It can be assumed that this difference led to a reduction in total power consumption. In this way, by having people who are dispersed across several areas gather in a specific area, it becomes possible to use the facilities described above.

[0037] Referring to Figure 5, the air conditioning control of this embodiment will be described. Figure 5 is a flowchart of the process applied to the air conditioning control of the embodiment.

[0038] The controller 20 calculates the indoor heat load Q for each area based on several conditions set by the operating pattern (S11). This calculation can be performed using the example described above.

[0039] The controller 20 sorts the calculated indoor heat load Q values ​​in ascending order (S12). The controller 20 uses the sorting results to allocate users to areas (rooms) with the smallest indoor heat load Q relative to the number of occupants (S13). By using the sorting results, even if there are users who cannot be accommodated in one area, they can be allocated in order from the area (room) with the smallest indoor heat load Q relative to the number of occupants.

[0040] The controller 20 determines a first control variable based on the user allocation plan and controls the environment of each area accordingly (<change of first control condition> (S14)).

[0041] For example, the controller 20 adjusts the environment of the "destination area" based on the user allocation plan as follows: • Adjust the ventilation rate (increase it as the number of people increases). • Adjust the air conditioner's temperature setting (lower it as the number of people increases).

[0042] Next, the access control device 40 calculates the number of users in each area. The controller 20 uses the user count information obtained from the access control device 40 to identify whether or not a user remains in the "source area" based on the user allocation plan (S15).

[0043] The controller 20 detects the occupancy status of each area, determines a second control variable, and controls the environment of each area accordingly (<change of second control condition> (S16)). The environment of each of the above areas is determined in order to guide the user to a specific area defined in step S13 above. For example, it is determined that the comfort level of this specific area is kept within a good range, while the comfort levels of the other areas are determined to deviate from a good range.

[0044] The control described in step S16 above will be illustrated as an example. If a user remains in the "area of ​​origin," the following control is performed (S16A). • Adjust the ventilation rate (adjust it to the appropriate level for the number of people). • Adjust (relax) the set temperature of the air conditioner. Once the above process is completed, the process from step S11 onwards is performed at predetermined intervals.

[0045] If no users remain in the "source area," the following control is performed (S16B). Turn off the air conditioning and ventilation, and turn off the lights. Once the above process is completed, the process from step S11 onwards is performed at predetermined intervals.

[0046] For example, if the number of users in the "original area" decreases, the amount of ventilation can be reduced accordingly. This reduces the power consumption of the ventilation fan, and the heat load decreases as a result of the reduced ventilation. By adjusting (relaxing) the set temperature of the air conditioner in response to this change in heat load, the power consumption of the air conditioner is also expected to decrease.

[0047] ==<<Control when in exit state>>== However, there are cases where the power consumption of the air conditioner does not decrease even when controlled using the above procedure (step S16B). Such cases will be explained below with reference to Figures 7 and 8.

[0048] Figure 7 is a diagram illustrating the relationship between the control of the air conditioner and other equipment and power consumption when the room is in the exit state according to the embodiment.

[0049] The graph in Figure 7 shows the change in power consumption when the air conditioner is stopped and when it continues to operate. When users leave an area, the air conditioner is turned off, resulting in a temporary cessation of power consumption. If the air conditioner is kept running, a decrease in power consumption is observed due to the reduced heat load from the number of users, but this is significantly different from when the air conditioner is turned off. Thus, when comparing power consumption over a short-term period, the results are as shown in the comparison analysis above.

[0050] However, when the air conditioner is turned off, the room temperature gradually changes to match the outside temperature. When an air conditioner is stopped and then restarted, it works to bring the room temperature, which has approached the outside temperature, back up to the set temperature. As a result, the power consumption will be far greater than when it is running continuously for a while after restarting.

[0051] Therefore, in this embodiment, we propose an example of operating the air conditioner according to the following procedure when the room is empty, based on the prediction of user behavior.

[0052] Figure 8 is a flowchart of the process related to the control of the air conditioner when the room is in the exit state according to the embodiment.

[0053] The controller 20 identifies whether there is one person in the target area based on the identification result of the camera image (S21). If there is more than one person in the room, the controller 20 repeats the determination process in step S21 at a predetermined interval.

[0054] If there is only one person in the target area, the controller 20 determines whether or not the person has left the room (S22). If the person has not left the room, the controller 20 repeats the determination process in step S21 at a predetermined interval.

[0055] When an occupant leaves the room, the controller 20 identifies whether it is likely to be a temporary departure or a permanent outing (S23).

[0056] If it is anticipated that the user will be going out, the controller 20 stops the air conditioning and ventilation in the target area and turns off the lights (S24). After completing this process, the series of processes ends.

[0057] If it is not expected that the person will leave the room, the controller 20 estimates the time when the person will return to the target area (S25).

[0058] The controller 20 calculates the power consumption for two cases: the first case in which the air conditioning is not operated from the time the occupants leave the target area until the time the occupants return to the target area, and the second case in which the air conditioning is operated (S26). The period for calculating power consumption may be the period from the time the air conditioning, which was temporarily stopped, is restarted and a predetermined time has elapsed until a predetermined time has elapsed.

[0059] Therefore, the controller 20 identifies whether the power consumption in the first case, where the system is stopped and not operated for a period of time, is expected to be less than the power consumption in the second case, where the system is kept in operation (S27). As a result, if it is expected that the power consumption in the first case will be reduced, the controller 20 stops the air conditioning and ventilation in the target area and turns off the lights (S28). After completing this process, the series of processes ends.

[0060] If, as a result, it is determined that the power consumption in the first case will not decrease, the controller 20 will relax the temperature setting of the air conditioning in the target area, stop ventilation, and turn off the lights (S29). After completing this process, the series of processes will be terminated.

[0061] Identifying the actions of occupants should be done based on the identification results of camera images capturing their actions, or on information about their planned activities for the day. For example, when using camera images for identification, if it is detected that a person in the room has left their seat with a bag, or that a person in the room has left their seat wearing a jacket (coat, etc.), it can be estimated that the person has been away for a relatively long time or will not return. It is best to classify such cases together as having left the premises.

[0062] By following the above procedure, air conditioners in areas where users are absent can be operated more efficiently.

[0063] (Controlling the environment based on user allocation plans) Refer to Figure 6 to explain how to control the environment based on the user allocation plan. Figure 6 is a graph showing the relationship between the PMV index and the PPD index in the embodiment. The relationship between the PMV index and the PPD index defines the range in which a thermal environment is perceived as comfortable. A PMV index exceeding ±1% is likely to cause discomfort more frequently. When the PPD index (discomfort rate) exceeds approximately 10%, it is expected that people will feel uncomfortable more often.

[0064] Therefore, the controller 20 controls the air conditioners (for example, air conditioners 11 and 13) using predetermined settings to, for example, set the PMV index to +1% or -1%, or the PPD index (discomfort rate) to over 10%. This is expected to increase the discomfort level of users in that area. When users perceive a decrease in comfort in an area where such control is being implemented, they are motivated to choose a more comfortable area and move there. In this way, controllers can guide users to other areas by using indirect methods of adjusting the environment of an area.

[0065] When determining the user allocation plan, there will be areas where it is expected that there will be zero users. The controller 20 should estimate the power consumption of the air conditioners in these areas where it is expected that there will be zero users by applying the process shown in Figure 8 above.

[0066] According to this embodiment, the air conditioning system 1 is configured to apply localized air conditioning that adjusts the temperature and ventilation rate in multiple areas within a building. The controller 20 of the air conditioning system 1 predicts a first power consumption by the air conditioner when it stops operating in a specific area where it is expected that users will be absent, and a second power consumption by the air conditioner when it operates in the specific area where it is expected that users will be absent. If the first power consumption is less than the second power consumption, the controller 20 stops operating the air conditioner in the area where users will be absent.

[0067] By using such an air conditioning system 1 to adjust the environment, the operation of air conditioners in specific areas where users are expected to be absent can be adjusted, thereby reducing the power consumption of air conditioners in areas where users are temporarily absent.

[0068] As described above, the controller 20 can reduce the energy consumption of air conditioners in specific areas where users are absent.

[0069] The embodiments of the present invention have been described above, but the air conditioning system 1 has a computer system inside. The series of processes related to the above-mentioned processing are stored in the form of a program on a computer-readable storage medium, and the above processing is performed when the computer reads and executes this program. Here, the computer-readable storage medium refers to a magnetic disk, magneto-optical disk, CD-ROM, DVD-ROM, semiconductor memory, etc. Alternatively, this computer program may be distributed to a computer via a communication line, and the computer that receives this distribution executes the program. Furthermore, the term "computer system" as used herein includes an OS, etc.

[0070] Although one embodiment of the present invention has been described above, the embodiments of the present invention are not limited to those described above. Embodiments of the present invention can be, for example, obtained by modifying the above embodiments as follows.

[0071] For example, in the above embodiment, for convenience, the configuration related to the present invention was described as if each function of the air conditioning system 1 were integrated into a single device, but each function may be appropriately distributed among multiple devices.

[0072] (Note) (1) The air conditioning system of the embodiment is capable of applying localized air conditioning to adjust the temperature and ventilation rate in multiple areas within a building. The air conditioning system includes a controller that predicts a first power consumption by an air conditioner when the operation of the air conditioner in a specific area where users are expected to be absent is stopped, and a second power consumption by the air conditioner when the air conditioner in the specific area where users are expected to be absent is operated, and stops the operation of the air conditioner in the area where users will be absent if the first power consumption is less than the second power consumption. (2) In the air conditioning system described in (1) above, the controller estimates the power consumption of the air conditioner for each of the periods, divided into the period of absence during which the user of the specific area is expected to be absent and the period of occupancy after the absence period. (3) In the air conditioning system described in (1) and (2) above, the controller uses the first power consumption during the absence period and the second power consumption during the occupancy period to estimate the total power consumption consumed by the air conditioner during the absence period and the occupancy period. (4) In the air conditioning system described in (1)-(3) above, the controller compares the first power consumption with the second first power consumption using the total power consumption. (5) In the air conditioning system described in (1)-(4) above, the controller calculates the indoor heat load Q for each of the multiple areas, including the specific area, and creates a user allocation plan that prioritizes assigning users to areas with a small indoor heat load Q relative to the number of people in each area, and calculates the power consumption of each area based on the user allocation plan. [Explanation of symbols]

[0073] 1. Air conditioning system 11, 12, 13 Air conditioners (air conditioning equipment, ventilation equipment) 20 controllers 30. Lighting equipment control device (lighting control) 31, 32, 33 Lighting equipment 40 Entry / exit control device r1, r2, r3 area

Claims

1. An air conditioning system that can apply localized air conditioning to adjust the temperature and ventilation rate in multiple areas within a building, The system predicts the first power consumption of the air conditioner when it stops operating in a specific area where users are expected to be absent, and the second power consumption of the air conditioner when it operates in a specific area where users are expected to be absent. A controller that stops the operation of the air conditioner in the area where the user is absent when the first power consumption is less than the second power consumption. An air conditioning system equipped with [specific features / features].

2. The aforementioned controller, The power consumption of the air conditioner is estimated for each of the following periods: the period of absence during which users of the aforementioned specific area are expected to be absent, and the period of occupancy following the absence. The air conditioning system according to claim 1.

3. The aforementioned controller, Using the first power consumption during the absence period and the second power consumption during the occupancy period, the total power consumption consumed by the air conditioner during the absence period and the occupancy period is estimated. The air conditioning system according to claim 2.

4. The aforementioned controller, The first power consumption and the second power consumption are compared using the total power consumption. The air conditioning system according to claim 3.

5. The aforementioned controller, The indoor heat load Q for each of the multiple areas, including the aforementioned specific area, is calculated for each area. A plan is created to allocate users to areas with a low indoor heat load Q, prioritizing users based on the number of people in each area. Based on the user allocation plan, calculate the power consumption for each area. The air conditioning system according to claim 4.

6. A control method for an air conditioning system that can apply localized air conditioning to adjust the temperature and ventilation rate of multiple areas within a building, The system predicts the first power consumption of the air conditioner when it stops operating in a specific area where users are expected to be absent, and the second power consumption of the air conditioner when it operates in a specific area where users are expected to be absent. If the first power consumption is less than the second power consumption, the operation of the air conditioner in the area where the user is absent will be stopped. A control method including

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