JP4498041B2 - Control method for air conditioning system - Google Patents

Description

  The present invention belongs to the technical field of a control method of an air conditioning system in which a plurality of variable air volume control devices are connected to an air conditioner.

  Conventionally, in an air conditioning system, the space to be air-conditioned is divided into a plurality of zones, the air supply side of each air conditioner is connected to each zone by a duct, and the air flow rate control device (hereinafter referred to as the air flow path to the air supply port of each zone) , VAV unit) is provided to control each zone individually and to control the air conditioner in consideration of the control state of each zone. That is, a local control method (a so-called variable air flow single duct method) is adopted in which the air supply amount is adjusted so that the indoor temperature setting value set individually is set in each zone. The air conditioner control employs a global control method in which the air supply amount and the supply air temperature are controlled in consideration of the air volume control status and the indoor temperature control status of each zone. However, in this control method, the maximum and minimum ranges are determined for the air flow rate of each VAV unit, and the temperature of each zone cannot be controlled to an individual target set temperature depending on the temperature of the air supplied by the air conditioner. Cases arise. For this reason, how to control the supply air temperature blown by the air conditioner is an important issue. That is, it is important how to determine the supply air temperature by grasping the indoor temperature control status of each zone. Below, the control system in a prior art is demonstrated.

Conventionally, load reset control has been used in which the required air volume ratio of each VAV unit in each zone is obtained, and the target supply air temperature of the air supplied by the air conditioner is calculated from the maximum value of the required air volume ratio in each zone. This method is excellent in that the control method is simple and control becomes easy. However, the definition (how to determine) the required air volume ratio may differ depending on the manufacturer of the VAV unit, and the required air volume ratio may differ under the same load condition even for the same model of the same manufacturer. However, there was a problem that the load situation could not be accurately grasped. In order to solve this problem, the present applicant has proposed a new method in which a parameter capable of accurately grasping the load state is introduced and has already filed an application (Patent Document 1).
Published Patent Publication, JP-A No. 2004-125296 (Supply Temperature Control Device for Air Conditioner)

Moreover, in order to solve the above problems, Patent Document 2 discloses an idea that the required air volume ratio is obtained with respect to the total required air volume (the sum of the required air volumes of the respective VAV units) to control the air conditioner. Has been. This concept will be briefly described below with reference to the drawings. FIG. 5 is a flowchart of an embodiment showing the concept of the present invention (prior art). In FIG. 5, in step S21, the air supply rate K1 of Equation 1 is obtained.

ここで、Ｑｒは各ゾーンの要求風量で、Ｑmin、Ｑmaxは各ゾーンのＶＡＶユニットで供給される風量の最小値、最大値を表す。なお、給気率Ｋ１の代わりに各ゾーンの目標給気量Ｑｔを利用して給気率Ｋ２を採用してもよい。ステップＳ２２では目標給気率Ｋｓとの偏差ΔＫ１＝Ｋ１−Ｋｓを求める。ステップＳ２３、Ｓ２６では偏差ΔＫ１が（−２、＋２）の範囲にあるかを判断し、該範囲外のときは運転モードが冷房か暖房かを判断する（ステップＳ２５，Ｓ３１）。ΔＫ１＞＋２で冷房のとき、又は、ΔＫ１＜−２で暖房のときは給気温度を０．５度下げる（ステップＳ２７）。ΔＫ１＞＋２で暖房のとき、又は、ΔＫ１＜−２で冷房のときは給気温度を０．５度上げる（ステップＳ３０）。ステップＳ２８では目標給気温度が、例えば（摂氏１６度、３３度）の範囲外になったときに目標給気率Ｋｓを所定のプログラム（例えば、文献の図３）に従って変更する。
公開特許公報、特開平８−１０５６４８（空気調和システム及び空気調和システムの制御方法）

Here, Qr is the required air volume of each zone, and Qmin and Qmax are the minimum and maximum air volume supplied by the VAV unit of each zone. Note that the air supply rate K2 may be adopted using the target air supply amount Qt of each zone instead of the air supply rate K1. In step S22, a deviation ΔK1 = K1−Ks from the target air supply rate Ks is obtained. In steps S23 and S26, it is determined whether or not the deviation ΔK1 is in the range of (−2, +2). If it is outside the range, it is determined whether the operation mode is cooling or heating (steps S25 and S31). When cooling with ΔK1> +2 or when heating with ΔK1 <−2, the supply air temperature is lowered by 0.5 degrees (step S27). When heating with ΔK1> +2 or when cooling with ΔK1 <−2, the supply air temperature is raised by 0.5 degrees (step S30). In step S28, the target air supply rate Ks is changed according to a predetermined program (for example, FIG. 3 in the literature) when the target air supply temperature is outside the range of, for example, (16 degrees Celsius, 33 degrees Celsius).
Published Patent Publication, JP-A-8-105648 (Air Conditioning System and Air Conditioning System Control Method)

  The effect of the above embodiment is described as follows. If the minimum target air supply rate Ks is set low, the air supply amount of the air supply fan can be reduced, so that the electric consumption can be reduced, and if the minimum target air supply rate Ks is set high, each zone can be ventilated quickly. So it can provide a clean indoor environment. Moreover, since the target air supply rate Ks is changed according to the target air supply temperature, it is possible to perform an optimal air conditioning process according to the load of the entire air conditioner. As is clear from the technical contents described above, in the present invention, the load reset of the supply air temperature is performed so that the supply air rate K1 matches the target air supply rate Ks. Further, the target air supply rate Ks is determined by the target air supply rate setting means in the graph shown in FIG. 3 of this document. However, there is a question as to whether or not the supply air temperature is appropriately controlled when the supply air rate K1 matches the target supply air rate Ks. That is, there is no guarantee that the target air supply rate Ks is reasonably determined (designed), and there is a doubt in making the air supply rate K1 coincide with the target air supply rate Ks. For example, there is a question as to how the target air supply rate Ks should be determined even when air conditioning is stopped in a certain zone.

In addition to this, many proposals regarding the control method (or control device) of the air conditioning system have been made. For example, in the conventional apparatus described in Patent Document 3, the damper opening degree of the VAV unit provided in the zone (controlled room) is a MAX value, and the deviation between the indoor set temperature and the indoor measured temperature is a predetermined value. If exceeded, a load reset command for "heating capacity increase request" or "cooling capacity increase request" to increase the capacity of the supply air temperature is sent to the controller of the air conditioner, and the controller resets the load in consideration of the temperature control mode. I do. In this conventional apparatus, since load reset is performed in response to a command issued from one VAV unit, there is a problem that a system having a large number of VAV units cannot efficiently control the entire system.
Patent Publication, JP-B-6-76854 (Load Reset Value Setting Method in VAV Control System)

Further, as other conventional techniques, there are those described in Patent Documents 4 and 5. In any of the conventional techniques described in these documents, the overall control status is obtained from the control status (control state) generated from the VAV unit in each zone, and the blowout air supply temperature is determined based on this and other conditions. To decide. This control status is obtained by dividing the control state space into a plurality of blocks on an appropriate scale. For example, in Patent Document 4, five control statuses are determined by using room temperature in each zone using a cooling set temperature, a heating set temperature, and a broken line of the damper opening. The overall control status is determined from a combination of control statuses of the zones. Therefore, since the control state space is divided into blocks, not only the state becomes discontinuous, but also the significance of the difference between the blocks is unclear, and it is difficult to rationally determine the overall control status, and the configuration There is a disadvantage that it becomes complicated. In addition, the control program is complicated.
Published patent publication, JP-A-9-178249 (VAV control system) Published patent publication, JP-A-8-28940 (VAV control system)

In the present invention, the temperature control of each zone (the room to be controlled) controls the temperature in the zone by controlling the damper opening of the VAV unit as in the prior art, while the supply temperature of the air conditioner is controlled. Therefore, a new parameter that can easily express the air conditioning load of the entire air conditioning system is introduced as an input parameter when determining the target supply air temperature, and the concept of the control method is simple and the control is easy. One purpose is to propose a maintained control method. That is, the present application improves and extends the technology described in Patent Document 1, eliminates the complicated configuration as described in Patent Documents 4 and 5, and requires different air volume depending on the size of the space in each zone. The purpose is to propose a simple and effective control system for air conditioners that can easily incorporate the differences in air conditioning and the importance of air conditioning. Therefore, the problem of the present invention is to propose a control method that has a condition that the control method is simple, accurately reflects the difference between each zone, and that the control is effective as judged from the entire system. This is one issue.
Further, in the conventional apparatus, the load reset correction width of the target supply air temperature is increased or decreased by a fixed temperature (for example, 0.5 degrees Celsius). Another object of the present invention is to propose a control system that can change the load reset correction width continuously and smoothly reach the target supply air temperature without causing hunting.

In order to solve the above problems, the present invention employs the following means. That is,
According to the first aspect of the present invention, the air-conditioning space is divided into a plurality of zones, a variable air volume control device is provided in each zone, and the air supply adjusted by the air conditioner is supplied to each zone by the variable air flow control device. In the control method of an air conditioning system in which each of the zones controls a supply air volume by a VAV controller based on a temperature sensor measurement signal installed in the zone and processes a heat load in the zone,
Indicates the required air volume and design air volume from the VAV controller in each zone , and indicates whether the variable air volume control device is operating or stopped, and is a state parameter that is zero when stopped, and the importance of air conditioning in the zone. Inputting a weight parameter;
Obtaining a zone parameter for each zone as a product of the state parameter for each zone and the weight parameter;
Obtaining a weighted total required air volume and a weighted total effective design air volume from the zone parameters of each zone;
Dividing the weighted total required air volume by the weighted total effective design air volume to obtain an effective required air volume ratio;
The method includes a step of obtaining a load reset correction width using the effective required air volume ratio, and a step of determining control of the air conditioner from a target supply air temperature corrected by the load reset correction width and an operation mode. And

The invention according to claim 2 is the invention according to claim 1, wherein the weight parameter is set to 1 for a standard zone, and is set to a value larger than 1 for a zone where air conditioning is important. A positive value smaller than 1 or zero is designated for a zone where air conditioning is not important .

According to a third aspect of the present invention, in the first or second aspect of the present invention, the step of obtaining the load reset correction width is an interval between the minimum value and the maximum value of the main range of the effective required air volume ratio. Is divided into three mode sections, the load reset correction width is continuously changed in the decrease mode section and the increase mode section, and the load reset correction width is made constant in the intermediate mode section .

According to a fourth aspect of the present invention, the air-conditioning space is divided into a plurality of zones, a variable air volume control device is provided in each zone, and the air supply adjusted by the air conditioner is supplied to each zone by the variable air flow control device. In the control method of an air conditioning system in which each zone controls the supply air volume and supply temperature to process the heat load in the zone, the step of obtaining the required air volume of each zone; and the request of each zone A step of obtaining an effective required air volume ratio from the air volume, a design air volume, and each zone parameter; a step of obtaining a load reset correction width using the effective required air volume ratio; and a target supply air temperature corrected by the load reset correction width And determining the control of the air conditioner from the operation mode, the step of obtaining the load reset correction width is a minimum value of a main range of the effective required air volume ratio. The section between large values is divided into three mode sections, the load reset correction width is continuously changed in the decrease mode section and the increase mode section, and the load reset correction width is made constant in the intermediate mode section And

  The supply air temperature is controlled by obtaining an effective required air volume ratio that appropriately expresses the effect of the entire system in consideration of the required air volume and the maximum design air volume and importance of each zone. The effect that the overall supply air temperature control can be effectively performed is obtained. In the invention according to claim 4, since the weighting of each zone is set to 1 as standard, the important one is specified to be larger than 1 and the unimportant one is specified to be smaller than 1, so that the weighting can be easily performed. There is also. Furthermore, in the invention described in claim 6, since the load reset correction width is continuously changed, an effect that the target supply air temperature can be reached smoothly is also obtained.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a control block diagram of an air conditioner. FIG. 2 shows an overall view of an air conditioning system embodying the present invention. FIG. 3 is a graph for obtaining the load reset correction width. FIG. 4 is a flowchart for obtaining the target supply air temperature.

  In FIG. 2, a coil C / C that supplies cold water via an electric valve 13 and a coil H / C that supplies hot water via an electric valve 14 are arranged on the upstream side of the air supply fan 12 of the air conditioner 11. The supply air temperature is controlled. An air supply duct 16 is connected to the air supply side of the air supply fan 12, and the air supply duct 16 is provided with a plurality of branch ducts 17. Air supply is supplied from the air supply port 18 to the inside of the zone 19 via a VAV unit (variable air volume control device) 20 provided in the branch duct 17. Each zone 19 is provided with a temperature sensor 21 for measuring the air temperature inside the zone, and the output of the temperature sensor 21 is connected to the controller 20 a of the VAV unit 20.

  Each zone 19 is provided with a return air port 23, and each return air port 23 is connected to a return air duct 25 via a branch duct 24 and is connected to a suction side of a return air fan 26. A part of the return air is discharged from the discharge port 27 to the outside air, and a part of the return air passes through the on-off valve 28 and is returned to the suction side of the air supply fan 12 as shown by the arrow in the drawing. In order to supplement a part of the released return air, the outside air sucked from the suction port 29 is supplied to the suction side of the air supply fan 12 as shown by the arrow in the figure.

The controller 20a of the VAV unit 20 is provided with a device for setting the target temperature in the zone. This controller obtains the deviation between the target temperature and the temperature measured by the temperature sensor 21, and performs conventional techniques such as PI control or proportional control. The air volume is determined using, and the temperature deviation is controlled to be zero. The air volume data at this time is transmitted to the zone controller 31 as “requested air volume”. The AHU controller 33 controls the chilled water valve 13 and the heating valve 14 based on the predetermined data described below sent from the zone controller 31 and the temperature measured by the supply air temperature sensor 32 provided in the supply air duct 16. To control the supply air temperature.

  FIG. 1 shows the functional details of the AHU controller 33. In FIG. 1, in addition to the required air volume of the VAV unit 20 in each zone 19, the zone controller 31 indicates the rated maximum air volume of each VAV unit 20 as “design air volume” data, and represents the operation or stop of each VAV unit 20. A state parameter and a weight parameter indicating the importance of control of the VAV unit 20 in each zone are input. For example, the weight parameter is set to “1” for a standard zone, a zone in which air conditioning is important (for example, a boardroom or a guest room) is larger than 1, and a zone in which air conditioning is not important. A positive value (or zero) smaller than 1 is attached. The status parameter is set to 1 for the operating VAV unit 20 and set to 0 for the stopped VAV unit 20. Instead of the weight parameter, a zone parameter indicating the product of the weight parameter of each zone and the state parameter may be input. The zone controller 31 calculates the weighted total required air volume, the weighted total effective design air volume, and the total required air volume from the above input data, and sends the calculation result to the AHU controller 33.

  Zone parameters (X (i), i = 1, 2, 3, .. n) for the VAV unit 20 for the i-th (i = 1, 2,... n) zone (weight parameter for the i-th zone) And (the state parameter for the i-th zone), the weighted total required air volume, the weighted effective design air volume, and the total required air volume can be described as in Equations 2 to 4.

数２〜数４において、「Ｑ（ｉ）」はｉ番目ゾーンのＶＡＶユニット２０の要求風量であり、「Ｑｏ（ｉ）」はｉ番目ゾーンのＶＡＶユニット２０の定格最大風量（又は設計風量）である。又、「Ｓ（ｉ）」はｉ番目ゾーンのＶＡＶユニット２０の状態パラメータである。

In Equations 2 to 4, “Q (i)” is the required air volume of the VAV unit 20 in the i-th zone, and “Qo (i)” is the rated maximum air volume (or design air volume) of the VAV unit 20 in the i-th zone. It is. “S (i)” is a state parameter of the VAV unit 20 in the i-th zone.

As shown in FIG. 1, the AHU controller 33 uses the weighted total effective design air volume (Equation 3) and the weighted total required air volume (Equation 2) from the zone controller 31 to calculate the effective required air volume. The ratio is defined as in Equation 5.

Next, the computing unit 35 obtains the load reset change width (ΔT) using the graph shown in FIG. In FIG. 3, the solid line shows the load reset change width (ΔT) during cooling, and the dotted line shows the load reset change width (ΔT) during heating. That is, as shown in FIG. 3, the load reset change width (ΔT) defines a main range for the range of the effective required air volume ratio, and has three stages between the minimum value (Jmin) and the maximum value (Jmax). , A minimum interval, a maximum interval (that is, an increase / decrease mode interval that requires a load reset), and an intermediate interval (that is, a constant interval that does not require a load reset). The load reset change width (ΔT) is linearly changed in the increase / decrease mode section, and the load reset change width (ΔT) is fixed (zero) in the constant mode section. Note that the load reset change width (ΔT) is set to the maximum value Dmax or the minimum value Dmin in the section other than the main range.

  Next, the calculating part 36 determines the supply air temperature Tsp set to a target value according to the flowchart shown in FIG. That is, in step S11, the load reset change width (ΔT) obtained by the calculation unit 35 is added to the previous target supply air temperature (Tsp) to obtain a new target supply air temperature (Tsp ′ = Tsp + ΔT). In step S12, the new target supply air temperature (Tsp ') is compared with the upper limit value, and if it is larger than the upper limit value, the new target supply air temperature (Tsp') is replaced with the upper limit value (Tsp '= upper limit value). Proceed to S16. If the new target supply air temperature (Tsp ') is smaller than the upper limit value in step S12, the process proceeds to step S14. In step S14, the target supply air temperature (Tsp ') is compared with the lower limit value, and if it is lower than the lower limit value, the new target supply air temperature (Tsp') is replaced with the lower limit value (Tsp '= lower limit value). Proceed to If it is larger than the lower limit, the new target supply air temperature (Tsp ′ = Tsp + ΔT) is left as it is, and the process proceeds to step S16.

  The calculation unit 37 calculates a deviation between the target supply air temperature (Tsp ′) obtained by the calculation unit 36 and the supply air temperature (Tpv) measured by the temperature sensor 32, and the calculation unit 38 performs PI control operation from the obtained deviation. A control amount is calculated. Based on this control amount, the arithmetic units 39 and 40 obtain the valve opening and control the electric valves 13 and 14. On the other hand, the calculation unit 41 determines the rotational speed of the air supply fan 12 based on the total required air volume from the zone controller 31 and controls the inverter 15.

  As described above, according to the present embodiment, the supply air temperature is obtained by determining the effective required air volume ratio that appropriately represents the operational effects of the entire system in consideration of the required air volume and the maximum design air volume and importance of each zone. As a result, the air supply control of the entire system, that is, the entire zone can be effectively performed. In addition, the weighting of each zone is set to 1 as standard, and the important one is specified to be larger than 1 and the unimportant one is specified to be smaller than 1, so that the weighting can be easily performed. In addition, since the target supply air temperature is continuously changed, it is possible not only to smoothly reset the load of the supply air temperature and maintain a comfortable environment, but also to save energy by saving wasted energy. Is also useful.

  The embodiments and examples of the present invention have been described in detail with reference to the drawings. However, the specific configuration is not limited to the examples, and there are design changes and the like without departing from the gist of the present invention. Are also included in the present invention. For example, the zone may correspond to a room partitioned by walls or the like, or may be a case where a space such as a large room is virtually divided. Further, although the return air is performed in the present embodiment, the present invention is also applied to the case where the air is discharged directly from the zone to the outside air without performing the return air. In addition, although two controllers (zone controller and AHU controller) are described separately, they may be configured as one controller.

The control block diagram of an air conditioner is shown. 1 shows an overall view of an air conditioning system embodying the present invention. It is a graph which calculates | requires a load reset change width. It is a flowchart which calculates | requires target air supply temperature. It is a flowchart which shows the control method of a conventional apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Air conditioner 12 Air supply fan 13, 14 Chilled water, heating valve 15 Inverter 16 Air supply duct 19 Zone 20 VAV unit (Variable air volume control device)
20a controller
21 Temperature Sensor 25 Return Air Duct 31 Zone Controller 32 Temperature Sensor 33 AHU Controller 34 Calculation Unit (Effective Required Air Volume Ratio Calculator)
35 Calculation unit (Supply temperature setting value calculator)

Claims (4)

Dividing the space conditioning to a plurality of zones, the provided Henfu amount control device in each zone, the supply air is adjusted by the air conditioner supplies air to each zone by the modified air flow control device, wherein each zone the zone In a control method of an air conditioning system in which a heat load in the zone is processed by controlling a supply air amount by a VAV controller based on a temperature sensor measurement signal installed in
Indicates the required air volume and design air volume from the VAV controller in each zone , and indicates whether the variable air volume control device is operating or stopped, and is a state parameter that is zero when stopped, and the importance of air conditioning in the zone. Inputting a weight parameter;
Obtaining a zone parameter for each zone as a product of the state parameter for each zone and the weight parameter;
Obtaining a weighted total required air volume and a weighted total effective design air volume from the zone parameters of each zone;
Dividing the weighted total required air volume by the weighted total effective design air volume to obtain an effective required air volume ratio;
The method includes a step of obtaining a load reset correction width using the effective required air volume ratio, and a step of determining control of the air conditioner from a target supply air temperature corrected by the load reset correction width and an operation mode. Control method for air conditioning system. The weight parameter is 1 for standard zones, a value greater than 1 for zones where air conditioning is important, and a positive value or zero less than 1 for zones where air conditioning is not important. The method for controlling an air conditioning system according to claim 1, wherein the air conditioning system is specified . The step of obtaining the load reset correction width includes dividing the section between the minimum value and the maximum value of the main range of the effective required air volume ratio into three mode sections, and the load reset correction width in the decrease mode section and the increase mode section. The method for controlling an air conditioning system according to claim 1 or 2, wherein the load reset correction width is constant in the intermediate mode section . A space to be air-conditioned is divided into a plurality of zones, and a variable air volume control device is provided in each zone, and the air adjusted by the air conditioner is supplied to each zone by the variable air flow control device. In a control method of an air conditioning system for processing a heat load in the zone by controlling an air volume and a supply air temperature, a step of obtaining a required air volume of each zone, a required air volume and a designed air volume of each zone, and each zone parameter A step of obtaining an effective required air volume ratio from the step, a step of obtaining a load reset correction width using the effective required air volume ratio, and a control of the air conditioner from a target supply air temperature and an operation mode corrected by the load reset correction width The step of determining the load reset correction range includes three steps between a minimum value and a maximum value of the main range of the effective required air volume ratio. Divided into mode section, decrease mode section and continuously varying the load reset Fixed width increase mode section, the control method of the air conditioning system, characterized in that the load reset correction range is constant in the intermediate mode section.

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