Air Conditioning System

Abstract

To provide an air conditioning system capable of performing dehumidification while keeping more thermal comfort.SOLUTION: An air conditioning system 1 comprises: a heat source machine 10 which generates cold water having a predetermined temperature; and an indoor unit 20 which has an air blower 21, introduces the cold water from the heat source machine 10 and operates the air blower 21 to thereby cool a room R. The air conditioning system further comprises: a first determination section determining whether an index value which is an index value indicating degree of comfort in the room R is within a set comfortable range; a second determination section determining whether humidity in the room R in which the indoor unit 20 is installed exceeds predetermined humidity; and a control section which, when the first determination section determines that the index value is within a comfortable range and the second determination section determines that humidity exceeds the predetermined humidity, causes the heat source machine 10 to generate cold water having a lower temperature than the predetermined temperature and causes the air blower 21 to keep current air flow volume when the air blower 21 is in operation.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an air conditioning system. [Background technology]

[0002] Conventionally, there is known an air conditioning system equipped with a heat source unit such as an absorption chiller and an indoor unit that cools the room using cold water from the heat source unit. Some of these air conditioning systems control the temperature of the cold water output from the heat source unit and the air volume of a blower provided in the indoor unit according to the target indoor temperature and indoor humidity (see, for example, Patent Documents 1 and 2). Such air conditioning systems can control environmental factors such as humidity while controlling the thermal comfort in the room. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2007-139241 A [Patent Document 2] JP 2011-27301 A Summary of the Invention [Problem to be solved by the invention]

[0004] In actual environments, there are cases where the environment is thermally comfortable but the humidity is high, and only dehumidification is desired. In such cases, conventionally, dehumidification is performed by supplying cold water to the indoor unit while increasing the airflow of the indoor unit, causing a lot of condensation to form. However, when dehumidification is performed, a cooling effect is also exerted at the same time, and the value of the thermal comfort index (for example, the value of the predicted average thermal sensation declaration) is likely to fall outside the comfortable range.

[0005] The present invention has been made to solve such problems, and an object of the present invention is to provide an air conditioning system that can perform dehumidification while maintaining better thermal comfort. [Means for solving the problem]

[0006] The air conditioning system of the present invention is an air conditioning system comprising a heat source unit that generates cold water at a predetermined temperature, and an indoor unit that is equipped with a blower and cools the room by introducing cold water from the heat source unit and operating the blower, and is equipped with a first judgment means for judging whether an index value, which is an index value indicating the comfort of the room, is within a set comfort range, a second judgment means for judging whether the humidity in the room in which the indoor unit is installed exceeds a predetermined humidity, and a control means for causing the heat source unit to generate cold water at a temperature lower than the predetermined temperature and maintaining the current air volume when the blower is operating when the first judgment means judges that the index value is within the comfort range and the second judgment means judges that the humidity exceeds the predetermined humidity. Effect of the Invention

[0007] According to the present invention, when the index value is judged to be within the comfort range and the humidity is judged to exceed the predetermined humidity, the heat source unit generates cold water at a temperature lower than the predetermined temperature, and the current air volume is maintained when the blower is in operation. Therefore, dehumidification is performed without increasing the airflow that contributes greatly to thermal comfort, making it easier to maintain thermal comfort. In particular, when there is no increase in the air volume, the dehumidification effect tends to decrease, but the decrease in the dehumidification effect is suppressed by lowering the cold water temperature output to the indoor unit. Therefore, dehumidification can be performed while maintaining better thermal comfort. [Brief description of the drawings]

[0008] [Figure 1] 1 is a configuration diagram showing an air conditioning system according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a partial configuration diagram of the air conditioning system shown in FIG. [Diagram 3] 4 is a flowchart showing the operation of an indoor unit that constitutes the air conditioning system according to the present embodiment. [Figure 4]4 is a flowchart showing the operation of a heat source unit that constitutes the air conditioning system according to the present embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] The present invention will be described below along with preferred embodiments. Note that the present invention is not limited to the embodiments shown below, and can be modified as appropriate within the scope of the present invention. In addition, in the embodiments shown below, some configurations are omitted from illustration and description, but it goes without saying that publicly known or well-known technologies are appropriately applied to the details of the omitted technologies within the scope of no contradiction with the contents described below.

[0010] Fig. 1 is a configuration diagram showing an air conditioning system according to this embodiment, and Fig. 2 is a partial configuration diagram of the air conditioning system shown in Fig. 1. As shown in Fig. 1 and Fig. 2, the air conditioning system 1 is configured such that each indoor unit 20 cools each room R using cold water from a heat source unit 10, and is equipped with the heat source unit 10, multiple indoor units 20, various sensors T, H, and pipes L1, L2.

[0011] The heat source unit 10 generates chilled water at a predetermined temperature (e.g., 7°C) and has a control unit (control means) 11. The control unit 11 controls the entire heat source unit 10 and can communicate with a control unit (reference numeral 22) of an indoor unit 20 described later. This heat source unit 10 may be, for example, an absorption chiller, a heat pump chiller, a vapor compression chiller, or the like, as long as it can generate chilled water at a predetermined temperature. Furthermore, the heat source unit 10 may be an absorption chiller / heater that can generate hot water in addition to chilled water. The chilled water at the predetermined temperature generated by the heat source unit 10 is supplied to each of the indoor units 20 installed in the multiple rooms R through the forward piping L1.

[0012] The multiple temperature sensors T are installed in the respective rooms R and output signals corresponding to the indoor temperatures. Similarly, the multiple humidity sensors H are installed in the respective rooms R and output signals corresponding to the indoor humidity. The signals corresponding to the indoor temperatures detected by the multiple temperature sensors T and the signals corresponding to the indoor humidity detected by the multiple humidity sensors H are transmitted to each indoor unit 20.

[0013] The indoor unit 20 is equipped with a blower 21, and introduces cold water from the heat source unit 10 and operates the blower 21 to send cold air into the room R to cool the room R. The indoor unit 20 is equipped with a control unit 22. The control unit 22 controls the entire indoor unit 20, and adjusts the air volume of the blower 21, etc. The cold water used for cooling by the indoor unit 20 is returned to the heat source unit 10 through the return pipe L2 at a temperature higher than a predetermined temperature, and is cooled again to the predetermined temperature in the heat source unit 10.

[0014] Here, the control section 22 according to this embodiment includes a first determination section (first determination means) 22a, a second determination section (second determination means) 22b, and an air volume control section (control means) 22c.

[0015] The first judgment unit 22a calculates a PMV (Predicted Mean Vote) value (index value) which is a value of a predicted average thermal sensation report (index indicating comfort) of the room R, and judges whether the PMV value is within a set comfort range (for example, greater than -0.5 and less than 0.5). The PMV value indicates thermal comfort based on a physical consideration from a human sensory amount, and is calculated based on the indoor temperature, indoor humidity, activity amount, amount of clothing, indoor wind speed, and radiation temperature. Therefore, the first judgment unit 22a calculates the PMV value based on the indoor temperature, indoor humidity, activity amount, amount of clothing, indoor wind speed, and radiation temperature. Of these, the measurement results by the temperature sensor T and the humidity sensor H are adopted for the indoor temperature and indoor humidity. For the activity amount, amount of clothing, indoor wind speed, and radiation temperature, fixed values ​​may be adopted, or values ​​other than fixed values ​​may be adopted. For example, a fixed value set based on what kind of activity is performed for each room R may be adopted for the amount of activity, but the air conditioning system 1 may be equipped with a sensor or a calculation unit that measures the amount of activity, and the measured value may be adopted as a value other than the fixed value. A fixed value according to the season or the like may be adopted for the amount of clothing, but the air conditioning system 1 may be equipped with a sensor or a calculation unit that measures the amount of clothing, and the measured value may be adopted as a value other than the fixed value. In addition, a fixed value such as zero may be adopted for the indoor air speed because it is an indoor environment, or, for example, the current air volume of the blower 21 may be adopted as a value other than the fixed value. Furthermore, when the indoor air speed is set to the current air volume of the blower 21, a value that takes into account the installation position of the indoor unit 20 may be adopted. In addition, the air conditioning system 1 may be equipped with a sensor or a calculation unit that measures the indoor air speed, and the measured value may be adopted as a value other than the fixed value. Furthermore, a value that takes into account whether the radiant temperature is on the top floor of a building or underground, etc. may be adopted, or the same value as the indoor temperature may be adopted as a value other than the fixed value. Furthermore, the air conditioning system 1 may include a sensor that measures the radiant temperature, a calculation unit, and the like, and these measured values ​​may be used as values ​​other than the fixed values.

[0016] The second determination unit 22b determines whether the humidity in the room R exceeds a predetermined humidity. That is, the second determination unit 22b compares the indoor humidity based on the signal of the humidity sensor H in each room R with the predetermined humidity, and determines whether the humidity in each room R exceeds the predetermined humidity.

[0017] Furthermore, when the first determination unit 22a determines that the PMV value is within the comfort range and the second determination unit 22b determines that the humidity in the room R exceeds a predetermined humidity, the control unit 22 transitions itself to a dehumidification mode. Furthermore, the control unit 22 transmits to the control unit 11 of the heat source unit 10 a message indicating that the control unit 22 has transitioned to the dehumidification mode.

[0018] The air volume control unit 22c controls the air volume of the blower 21. If the blower 21 is in operation when the dehumidification mode is entered, the air volume control unit 22c maintains the current air volume. If the blower 21 is stopped when the dehumidification mode is entered, the air volume control unit 22c starts operation at the minimum air volume.

[0019] Here, in a conventional indoor unit, when performing a dehumidification operation, the dehumidification effect is enhanced by exposing a large amount of indoor air to a pipe (e.g., a coil) through which cold water from the heat source unit 10 flows. In other words, the air volume tends to increase. However, in this embodiment, when the blower 21 is stopped, the unit is operated at the minimum air volume, but otherwise the air volume is maintained.

[0020] Furthermore, the control unit 11 of the heat source unit 10 performs dehumidification-compatible operation when the number of indoor units 20 in the dehumidification mode (i.e., the number of indoor spaces R targeted for dehumidification) exceeds a predetermined percentage of the total (e.g., 60%). At this time, the control unit 11 causes the heat source unit 10 to generate cold water at a temperature lower than the predetermined temperature. Specifically, the control unit 11 normally generates cold water at 7°C, but generates cold water at 5°C in the dehumidification-compatible operation.

[0021] Therefore, in the air conditioning system 1 according to this embodiment, the dehumidification effect is achieved by lowering the cold water temperature while basically maintaining the air volume of the blower 21 during dehumidification. In particular, since the air volume is basically maintained, it is possible to maintain the airflow that contributes greatly to thermal comfort, and to prevent people in the room R from feeling colder during dehumidification (it is possible to prevent the loss of thermal comfort).

[0022] Next, the operation of the air conditioning system 1 according to this embodiment will be described. Fig. 3 is a flowchart showing the operation of the indoor unit 20 constituting the air conditioning system 1 according to this embodiment. The process shown in Fig. 3 is repeatedly executed until the power supply of the indoor unit 20 is turned off.

[0023] As shown in FIG. 3, first, the first judgment unit 22a judges whether the PMV value is within the comfortable range (S1). If the PMV value is not within the comfortable range (S1: NO), the air volume control unit 22c automatically controls the air volume of the blower 21 (S2). In this process, the air volume control unit 22c automatically adjusts the air volume so that the air volume increases as the PMV value deviates from the comfortable range (for example, the air volume is controlled by selecting from LOW, MIDDLE, and HIGH). Thereafter, the process returns to step S1. In this embodiment, the air volume is controlled in three stages, LOW, MIDDLE, and HIGH, but is not limited to this, and two or four or more stages of air volume control may be performed, or stepless (continuous) air volume control may be performed. Below, the air volume control will be described assuming three stages, LOW, MIDDLE, and HIGH.

[0024] If the PMV value is within the comfortable range (S1: YES), the second judgment unit 22b judges whether the indoor humidity exceeds a predetermined humidity (S3). If the indoor humidity does not exceed the predetermined humidity (S3: NO), the air volume control unit 22c automatically controls the air volume of the blower 21 (S2). If the judgment in step S1 is "YES" and the judgment in step S3 is "NO", it is comfortable in terms of both heat and humidity. Therefore, the air volume control unit 22c controls the airflow to maintain the current state. That is, if thermal comfort can be maintained with the air volume OFF, the air volume control unit 22c turns the air volume OFF. Or, if the PMV value starts to deviate from the target PMV value, the air volume control unit 22c automatically adjusts the air volume to maintain thermal comfort, for example, by turning the air volume LOW.

[0025] If the indoor humidity exceeds the predetermined humidity (S3: YES), it can be said that the room is thermally comfortable but humidly uncomfortable. Therefore, the control unit 22 turns on the dehumidification mode (S4). In this process, the control unit 22 transmits a signal to the heat source unit 10 indicating that the control unit 22 has switched to the dehumidification mode. Next, the control unit 22 determines whether the air volume is currently OFF (i.e., whether the blower 21 is OFF) (S5).

[0026] If the air volume is not OFF (S5: NO), the air volume control unit 22c maintains the current air volume (S6). That is, if the current air volume is LOW, the air volume control unit 22c maintains it at LOW, and if the current air volume is MIDDLE, the air volume control unit 22c maintains it at MIDDLE. Also, if the current air volume is HIGH, the air volume control unit 22c maintains it at HIGH. After that, the process proceeds to step S8.

[0027] If the air volume is OFF (S5: YES), the air volume control unit 22c sets the air volume to LOW (S7). That is, since the blower 21 is stopped, the air volume control unit 22c starts operation at the minimum air volume. After that, the process proceeds to step S8.

[0028] In step S8, the first judgment unit 22a judges again whether the PMV value is within the comfort range (S8). If the PMV value is not within the comfort range (S8: NO), that is, if the thermal comfort has been impaired by the dehumidification operation, the process proceeds to step S10, and the control unit 22 turns off the dehumidification mode (S10). At this time, the control unit 22 transmits a signal to the heat source unit 10 indicating that it is no longer in the dehumidification mode. After that, the process proceeds to step S1.

[0029] If the PMV value is within the comfort range (S8: YES), the second judgment unit 22b judges whether the indoor humidity is less than the specified humidity (S9). Here, the specified humidity is preferably lower than the humidity determined in step S3. If the indoor humidity is not less than the specified humidity (S9: NO), the process proceeds to step S5.

[0030] On the other hand, if the indoor humidity is less than the specified humidity (S9: YES), the humidity has become comfortable while maintaining thermal comfort, so the control unit 22 turns off the dehumidification mode (S10). In this process, the control unit 22 also transmits a signal to the heat source unit 10 indicating that it is no longer in the dehumidification mode. After that, the process proceeds to step S1.

[0031] Fig. 4 is a flowchart showing the operation of the heat source unit 10 constituting the air conditioning system 1 according to this embodiment. The process shown in Fig. 4 is repeatedly executed until the power supply of the heat source unit 10 is turned off.

[0032] 4, first, the control unit 11 normally operates the heat source unit 10 (S11). At this time, the control unit 11 sets the temperature of cold water supplied to the indoor unit 20 through the supply pipe L1 (cold water outlet temperature) to, for example, 7°C.

[0033] Next, the control unit 11 judges whether the number of indoor units 20 in the dehumidification mode ON exceeds a first predetermined % (e.g., 60%) based on the signals from each indoor unit 20 (S12). If the number of indoor units 20 in the dehumidification mode ON does not exceed the first predetermined % (S12: NO), this process is repeated until it is judged that the number exceeds the first predetermined %.

[0034] On the other hand, if the number of indoor units 20 with the dehumidification mode ON exceeds the first predetermined percentage (S12: YES), the control unit 11 turns on the dehumidification compatible operation (S13). As a result, the control unit 11 controls the heat source unit 10 so that the chilled water outlet temperature is, for example, 5°C (S14).

[0035] Thereafter, the control unit 11 judges whether the number of indoor units 20 in the dehumidification mode ON is equal to or less than a second predetermined % (a value equal to or less than the first predetermined %, for example, 40%) (S15) based on the signal from each indoor unit 20. If the number of indoor units 20 in the dehumidification mode ON is not equal to or less than the second predetermined % (S15: NO), the process proceeds to step S14.

[0036] On the other hand, if the number of indoor units 20 with the dehumidification mode ON is equal to or less than the second predetermined percentage (S15: YES), the control unit 11 turns off the dehumidification compatible operation (S16). After that, the process proceeds to step S11.

[0037] In this way, according to the air conditioning system 1 of this embodiment, when it is determined that the PMV value is within the comfort range and the humidity exceeds the predetermined humidity, the heat source unit 10 generates cold water at a temperature lower than the predetermined temperature, and when the blower 21 is in operation, the air volume is maintained at the current level. Therefore, dehumidification is performed without increasing the airflow that contributes greatly to thermal comfort, making it easier to maintain thermal comfort. In particular, when there is no increase in the air volume, the dehumidification effect tends to decrease, but the decrease in the dehumidification effect is suppressed by lowering the cold water temperature output to the indoor unit 20. Therefore, dehumidification can be performed while maintaining better thermal comfort.

[0038] Furthermore, when it is determined that the PMV value is within the comfort range and that the humidity exceeds a predetermined humidity, cold water at a temperature lower than a predetermined temperature is generated by the heat source unit 10, and when the blower 21 is stopped, operation of the blower 21 is started at the minimum airflow rate of the blower 21. Therefore, when thermal comfort can be maintained with the indoor unit 20 not in operation, the blower 21 is operated at the minimum airflow rate, making it possible to perform dehumidification while maintaining better thermal comfort.

[0039] Furthermore, when the number of rooms R to be dehumidified for which the PMV value is determined to be within the comfort range and the humidity is determined to exceed the predetermined humidity exceeds a predetermined ratio of the total number, cold water at a temperature lower than the predetermined temperature is generated by the heat source unit 10, and when the blower 21 is in operation, the air volume is maintained as it is. Therefore, when cold water is supplied to multiple indoor units 20 by one heat source unit 10, dehumidification is performed while maintaining the overall thermal comfort of the multiple rooms R, and air conditioning taking the entire room into consideration can be performed.

[0040] Although the present invention has been described above based on the embodiments, the present invention is not limited to the above embodiments, and may be modified without departing from the spirit of the present invention, and other techniques may be appropriately combined to the extent possible. Furthermore, known or well-known techniques may be combined to the extent possible.

[0041] For example, in the above embodiment, the air conditioning system 1 supplies chilled water generated in one heat source unit 10 to multiple indoor units 20, but is not particularly limited to this, and may supply chilled water generated in one heat source unit 10 to one indoor unit 20. Furthermore, there may be multiple heat source units 10, and chilled water generated in the multiple heat source units 10 may be supplied to one or multiple indoor units 20.

[0042] Also, in the above embodiment, each of the multiple indoor units 20 is provided with a control unit 22, but this is not limiting, and for example, a configuration in which one control unit 22 controls multiple indoor units 20 may be used. Furthermore, a higher-level control unit that controls or integrates the control unit 11 of the heat source unit 10 and the control units 22 of the indoor units 20 may be provided, and the processing of the first determination unit 22a and the second determination unit 22b, etc. may be executed in the higher-level control unit. In other words, as long as the control unit controls the air conditioning system 1, it may be provided in the heat source unit 10, the air conditioner 20, or outside both.

[0043] Furthermore, when the dehumidification compatible operation is OFF, the heat source unit 10 according to this embodiment generates chilled water at a predetermined temperature, but this predetermined temperature may be variable. For example, when it is desired to obtain a large cooling effect in the air conditioning system 1, the heat source unit 10 may be controlled to generate chilled water at 6°C or the like. Furthermore, when the dehumidification compatible operation is turned ON from this state, chilled water at a temperature lower than 6°C or the like (predetermined temperature) may be generated.

[0044] In addition, in this embodiment, the predicted average thermal sensation declaration has been described as an example of an index indicating comfort. However, the index is not limited to the predicted average thermal sensation declaration. For example, the index may be effective temperature (ET), operative temperature (OT), windchill index (WCI), heat stress index (HSI), wet bulb globe temperature (WBGT), discomfort index (THI), or standard effective temperature (SET*) as long as it indicates comfort. It goes without saying that when any of these indexes is adopted, a sensor or a calculation unit is required to calculate the value of the index. In particular, since dehumidification is performed in the present invention, it is preferable to adopt an index that requires a humidity value (or a temperature value) to calculate the index value. [Explanation of symbols]

[0045] 1: Air conditioning system 10: Heat source machine 11: Control section (control means) 20: Indoor unit 21: Blower 22: Control section 22a: First judgment unit (first judgment means) 22b: Second judgment unit (second judgment means) 22c: Air volume control unit (control means) H: Humidity sensor L1: Supply piping L2: Return pipe R: Indoor T: Temperature sensor

Claims

1. An air conditioning system including a heat source unit that generates cold water at a predetermined temperature, and an indoor unit that is equipped with a blower and introduces the cold water from the heat source unit and operates the blower to cool a room, a first determination means for determining whether an index value, which is a value of an index indicating indoor comfort, is within a set comfort range; A second determination means for determining whether the humidity in the room in which the indoor unit is installed exceeds a predetermined humidity; a control means for causing the heat source unit to generate cold water at a temperature lower than the predetermined temperature when the first determination means determines that the index value is within a comfortable range and the second determination means determines that the humidity exceeds the predetermined humidity, and for maintaining the current air volume when the blower is in operation; An air conditioning system comprising:

2. When the first determination means determines that the index value is within a comfortable range and the second determination means determines that the humidity exceeds the predetermined humidity, the control means causes the heat source unit to generate cold water at a temperature lower than the predetermined temperature, and starts operation of the blower at a minimum air volume when the blower is stopped.

2. The air conditioning system according to claim 1.

3. The indoor unit includes a plurality of indoor units each cooling a plurality of rooms, the first determination means and the second determination means determine, for each of a plurality of rooms, whether or not the index value is within a comfortable range and whether or not the humidity in the room exceeds the predetermined humidity; The control means, when the number of rooms to be dehumidified, among the plurality of rooms, in which the index value is determined to be within a comfortable range by the first determination means and the humidity is determined to exceed the predetermined humidity by the second determination means, exceeds a predetermined ratio of the total number of rooms, causes the heat source unit to generate cold water at a temperature lower than the predetermined temperature, and maintains the current air volume when the blower in the room to be dehumidified is in operation.

3. An air conditioning system according to claim 1 or 2.

Images