Air conditioning system

Abstract

To provide an air conditioning system capable of more reliably preventing freezing of a heat medium flowing through a heat exchange coil.SOLUTION: An air conditioning system 1 includes: an air conditioner 10 that adjusts the temperature of outdoor air OA1 and sends it indoors; and a control device 50 comprising a control unit that controls the air conditioner 10. The air conditioner 10 includes: a preheating coil 11 to which first circulating water W1 being hot water is supplied during heating operation; a first valve V1 that adjusts the flow rate of the first circulating water W1 supplied to the preheating coil 11; a flow rate measurement unit 21 that measures the flow rate of the first circulating water W1 supplied to the preheating coil 11; and a water temperature measurement unit 31 that measures the temperature of the first circulating water W1 having passed through the preheating coil 11. During heating operation, the control unit identifies a lower limit of the opening of the first valve V1 based on the flow rate and the water temperature of the first circulating water W1, and adjusts the opening of the first valve V1 so as not to fall below the lower limit.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] In an air conditioning system that takes in air from outdoors and blows it indoors, the temperature of the outside air is adjusted by exchanging heat between the outside air and a heat medium such as circulating water that circulates through a heat exchange coil (see, for example, Patent Document 1).

[0003] In cold regions, the outside air temperature may drop below 0°C, and if the flow rate of the heat medium flowing through the heat exchange coil that exchanges heat with the outside air is low, there is a risk that the heat medium may freeze in the heat exchange coil. Conventionally, in order to prevent the heat medium from freezing in the heat exchange coil in winter, a predetermined lower limit is set for the opening of a valve that controls the flow rate of the heat medium flowing through the heat exchange coil. Setting a predetermined lower limit for the opening of the valve prevents the flow rate of the circulating water flowing through the heat exchange coil from becoming excessively low. This prevents the circulating water from freezing in the heat exchange coil. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2009-216321 A Summary of the Invention [Problem to be solved by the invention]

[0005] The flow rate of the heat transfer medium in the heat exchange coil depends not only on the valve opening but also on other important factors such as the water pressure of the heat transfer medium. Therefore, simply adjusting the valve opening so that the flow rate does not fall below a preset lower limit is sometimes insufficient as a countermeasure against freezing of the heat transfer medium. [Means for solving the problem]

[0006] An air conditioning system that solves the above problem comprises an air conditioner that adjusts the temperature of outside air and blows it indoors, and a control unit that controls the air conditioner, wherein the air conditioner comprises a coil to which circulating water is supplied during heating operation, a valve that adjusts the flow rate of the circulating water supplied to the coil, and a measurement unit that measures status information of the circulating water supplied to the coil, and during the heating operation, the control unit identifies a lower limit for the opening of the valve based on the status information measured by the measurement unit, and adjusts the opening so that it does not fall below the lower limit. Effect of the Invention

[0007] According to the present invention, the heat medium flowing through the heat exchange coil can be prevented from freezing more reliably. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic diagram showing the configuration of an air conditioner provided in an air conditioning system. [Diagram 2] FIG. 2 is a schematic diagram showing a supply form of circulating water to the preheating coil. [Diagram 3] FIG. 3 is an explanatory diagram of a hardware configuration according to the embodiment. [Figure 4] FIG. 4 is a block diagram showing the configuration of a control device of the air conditioning system. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] An embodiment of an air conditioning system will be described with reference to Figs. 1 to 4. As shown in FIG. 1, the air conditioning system 1 includes an air conditioner 10 and a control device 50. The air conditioner 10 takes in outside air OA1 and adjusts the temperature of the taken in outside air OA1 to supply it indoors as temperature-controlled air CA1. The control device 50 controls the operation of the air conditioner 10. The air conditioner 10 can switch between heating operation and cooling operation. Note that the air conditioning system 1 may include multiple air conditioners 10, as described later. Also, the air conditioner 10 may supply a mixture of the taken in outside air OA1 and return air from indoors to the indoors as temperature-controlled air CA1.

[0010] [Air conditioner] In the air conditioner 10, a preheating coil 11, a heating coil 12, a cooling coil 13, a reheating coil 14, and a fan 15 are arranged in this order from the outdoor side to the indoor side. In addition, humidifiers 16 are arranged between the preheating coil 11 and the heating coil 12, and between the heating coil 12 and the cooling coil 13. The outside air OA1 taken into the air conditioner 10 passes through each of the above-mentioned components and is then supplied indoors as temperature-controlled air CA1. The air conditioner 10 may be provided with an air filter on the outdoor side of the preheating coil 11 to remove foreign matter such as dust contained in the outside air OA1.

[0011] The preheating coil 11 preheats the outdoor air OA1 during heating operation. The heating coil 12 further heats the outdoor air OA1 preheated by the preheating coil 11 during heating operation. The cooling coil 13 cools the outdoor air OA1 during cooling operation. The reheating coil 14 reheats the outdoor air OA1 cooled by the cooling coil 13 during cooling operation. In this embodiment, "reheating" refers to reheating the outdoor air OA1 cooled by the cooling coil 13 to a dew point temperature or lower for dehumidification, to an appropriate temperature during cooling operation.

[0012] That is, during heating operation of the air conditioner 10, first, the outdoor air OA1 is preheated by the preheating coil 11, and then the outdoor air OA1 is further heated by the heating coil 12. Note that during heating operation, the outdoor air OA1 preheated by the heating coil 12 may be further heated using the reheating coil 14. Also, during cooling operation of the air conditioner 10, first, the outdoor air OA1 is cooled and dehumidified by the cooling coil 13, and then the outdoor air OA1 is reheated by the reheating coil 14.

[0013] The air conditioner 10 includes an outdoor air temperature measuring unit 17. The outdoor air temperature measuring unit 17 measures the temperature of the outdoor air OA1 taken into the air conditioner 10, i.e., the outdoor air temperature. The outdoor air temperature measured by the outdoor air temperature measuring unit 17 is transmitted to the control device 50. The air conditioner 10 may include a measuring unit for measuring the temperature of the outdoor air OA1 that has passed through each of the coils 11-14.

[0014] The preheating coil 11 is supplied with the first circulating water W1. The heating coil 12 is supplied with the second circulating water W2. The cooling coil 13 is supplied with the third circulating water W3. The reheating coil 14 is supplied with the fourth circulating water W4. The temperatures of the circulating waters W1 to W4 are adjusted by respective heat source devices. The circulating waters W1 to W4 are an example of a heat medium flowing through each of the coils 11 to 14.

[0015] The air conditioner 10 includes a first valve V1, a second valve V2, a third valve V3, and a fourth valve V4. The first valve V1 adjusts the flow rate of the first circulating water W1 supplied to the preheating coil 11. The second valve V2 adjusts the flow rate of the second circulating water W2 supplied to the heating coil 12. The third valve V3 adjusts the flow rate of the third circulating water W3 supplied to the cooling coil 13. The fourth valve V4 adjusts the flow rate of the fourth circulating water W4 supplied to the reheating coil 14.

[0016] The openings of the first valve V1, the second valve V2, the third valve V3, and the fourth valve V4 are adjusted by the control device 50. The control device 50 performs proportional control of the openings of the first valve V1, the second valve V2, the third valve V3, and the fourth valve V4, respectively, according to the temperature and air volume required for the temperature-controlled air CA1. The openings of the first valve V1, the second valve V2, the third valve V3, and the fourth valve V4 are adjusted between 0% and 100%. The first valve V1 has a lower limit of opening during anti-freeze control, which will be described later. In this embodiment, the "proportional control" refers to a control form in which, in the automatic control of the openings of the first valve V1 to the fourth valve V4, a deviation between the current opening value and the target opening value is detected, and the opening is controlled with an operation amount proportional to the deviation.

[0017] The air conditioner 10 includes a first flow rate measuring unit 21, a second flow rate measuring unit 22, a third flow rate measuring unit 23, and a fourth flow rate measuring unit 24. The first flow rate measuring unit 21 measures the flow rate of the first circulating water W1 supplied to the preheating coil 11. The second flow rate measuring unit 22 measures the flow rate of the second circulating water W2 supplied to the heating coil 12. The third flow rate measuring unit 23 measures the flow rate of the third circulating water W3 supplied to the cooling coil 13. The fourth flow rate measuring unit 24 measures the flow rate of the fourth circulating water W4 supplied to the reheating coil 14. The flow rates of each unit measured by the first flow rate measuring unit 21, the second flow rate measuring unit 22, the third flow rate measuring unit 23, and the fourth flow rate measuring unit 24 are transmitted to the control device 50.

[0018] The flow rate measuring units 21-24 are an example of a measuring unit that measures the flow rate of the circulating water W1-W4 supplied to each of the coils 11-14. The flow rate of the circulating water W1-W4 supplied to each of the coils 11-14 is an example of status information of the circulating water W1-W4 supplied to each of the coils 11-14.

[0019] The air conditioner 10 includes a first water temperature measuring unit 31, a second water temperature measuring unit 32, a third water temperature measuring unit 33, and a fourth water temperature measuring unit 34. The first water temperature measuring unit 31 measures the water temperature of the first circulating water W1 that has passed through the preheating coil 11. The second water temperature measuring unit 32 measures the water temperature of the second circulating water W2 that has passed through the heating coil 12. The third water temperature measuring unit 33 measures the water temperature of the third circulating water W3 that has passed through the cooling coil 13. The fourth water temperature measuring unit 34 measures the water temperature of the fourth circulating water W4 that has passed through the reheating coil 14. The water temperatures of each unit measured by the first water temperature measuring unit 31, the second water temperature measuring unit 32, the third water temperature measuring unit 33, and the fourth water temperature measuring unit 34 are transmitted to the control device 50.

[0020] The water temperature measuring units 31-34 are an example of a measuring unit that measures the water temperature of the circulating water W1-W4 having passed through each of the coils 11-14. The water temperature of the circulating water W1-W4 having passed through each of the coils 11-14 is an example of status information of the circulating water W1-W4 supplied to each of the coils 11-14.

[0021] [Circulating water supply to each coil] The manner in which the circulating water W1-W4 is supplied to each of the coils 11-14 will be described with reference to Fig. 2. In the following, as an example, the manner in which the first circulating water W1 is supplied to the preheating coil 11 in a case in which the air conditioning system 1 includes a plurality of air conditioners 10 will be described. The supply of the circulating water W2-W4 to the other coils 12-14 can be performed in the same manner as the supply of the first circulating water W1 to the preheating coil 11. Also, in Fig. 2, the supply paths (including the second valve V2-fourth valve V4, etc.) of the circulating water W2-W4 to the other coils 12-14, the humidifier 16, and the outdoor air temperature measuring unit 17 are not shown.

[0022] 2, the air conditioning system 1 includes a plurality of air conditioners 10. For example, in the air conditioning system 1, an air conditioner 10 is provided on each floor of a building. The air conditioning system 1 includes a heat source device 40 and a pump 41. The heat source device 40 is, for example, a heat pump that adjusts the temperature of the first circulating water W1. The pump 41 supplies the first circulating water W1 to the preheating coil 11 of each air conditioner 10. In other words, the air conditioning system 1 is configured as a central heat source system including a plurality of air conditioners 10 and a heat source device 40 that supplies heat thereto. The heat source device 40 and the pump 41 are controlled by a control device 50.

[0023] The amount of the first circulating water W1 sent from the pump 41 to each preheating coil 11 is adjusted by a first valve V1 provided in each preheating coil 11. That is, the flow rate of the first circulating water W1 supplied to each preheating coil 11 is determined by the output of the pump 41 and the opening degree of each first valve V1. In other words, the flow rate of the first circulating water W1 supplied to one preheating coil 11 also depends on the opening degree of the first valve V1 connected to the other preheating coil 11.

[0024] The first circulating water W1 that has passed through the preheating coil 11 is returned to the heat source device 40. The flow rate of the first circulating water W1 supplied to each preheating coil 11 is measured by a first flow rate measuring unit 21. The temperature of the first circulating water W1 that has passed through each preheating coil 11 is measured by a first water temperature measuring unit 31.

[0025] [Hardware configuration] 3, a hardware configuration of the information processing device H10 constituting the control device 50 will be described. The information processing device H10 includes a communication device H11, an input device H12, a display device H13, a storage device H14, and a processor H15. Note that this hardware configuration is an example, and it may be realized by other hardware.

[0026] The communication device H11 is an interface that transmits and receives data by establishing a communication path with other devices. The input device H12 is a device such as a mouse or keyboard that accepts input of various information. The display device H13 is a display or the like that displays various information. The storage device H14 is a storage device that stores data and various programs for executing various functions of the control device 50. The processor H15 controls each process in the control device 50 by using the programs and data stored in the storage device H14. The processor H15 is, for example, a CPU or an MPU. The processor H15 executes various processes for each process by expanding programs stored in a ROM or the like into a RAM.

[0027] [Control device configuration] A specific configuration of the control device 50 will be described with reference to FIG. 4, the control device 50 includes a control unit 51 and a storage unit 52. The control unit 51 controls the operation of each unit in the air conditioning system 1. The storage unit 52 stores programs and various information used by the control unit 51 to control the operation of each unit in the air conditioning system 1.

[0028] The control unit 51 executes a freeze prevention program, thereby functioning as a judgment unit 51A and a lower limit value setting unit 51B. The judgment unit 51A judges whether or not to perform freeze prevention control in accordance with the outside air temperature during heating operation. The lower limit value setting unit 51B specifies a lower limit value of the opening degree of the first valve V1 as the freeze prevention control based on state information of the first circulating water W1 supplied to the preheating coil 11. The freeze prevention program is stored in the memory unit 52.

[0029] The storage unit 52 stores a threshold value for the determination unit 51A to determine whether or not to perform anti-freeze control. The storage unit 52 includes a flow velocity information storage unit 52A and a water temperature information storage unit 52B as a database for storing various information for the lower limit value setting unit 51B to specify the lower limit value of the opening degree of the first valve V1.

[0030] The flow velocity information storage unit 52A stores the flow velocity information. The flow velocity information is a relational expression or a table for calculating the opening degree of the first valve V1 when the flow velocity of the first circulating water W1 flowing through the preheating coil 11 reaches a predetermined flow velocity lower limit value from the correspondence relationship between the flow rate of the first circulating water W1 and the opening degree of the first valve V1. The flow velocity lower limit value is the flow velocity of the first circulating water W1 required to prevent the first circulating water W1 flowing through the preheating coil 11 from freezing. The flow velocity lower limit value is, for example, 0.1 m / s or more and 0.5 m / s or less, for example, 0.3 m / s. For example, the preheating coil 11 is configured so that when the first circulating water W1 is supplied to the preheating coil 11 at a flow rate of 121 L / min, the flow velocity of the first circulating water W1 flowing through the preheating coil 11 is about 0.3 m / s.

[0031] The water temperature information storage unit 52B stores water temperature information. This water temperature information is a relational expression or a table for calculating the opening degree of the first valve V1 when the water temperature of the first circulating water W1 passing through the preheating coil 11 reaches a predetermined water temperature lower limit value from the correspondence relationship between the water temperature of the first circulating water W1 and the opening degree of the first valve V1. The water temperature lower limit value is the water temperature of the first circulating water W1 required to prevent freezing of the first circulating water W1 flowing through the preheating coil 11. The water temperature lower limit value is, for example, 1°C or more and 5°C or less, for example, 3°C.

[0032] [Anti-freeze control] The following describes the anti-freezing control when the air conditioner 10 is in heating operation. During heating operation, the first circulating water W1 in a hot water state is supplied to the preheating coil 11, and the second circulating water W2 in a hot water state is supplied to the heating coil 12.

[0033] The anti-freeze control is performed when the air conditioner 10 is in heating operation and the outside air temperature is equal to or lower than a threshold. The determination unit 51A determines whether the outside air temperature is equal to or lower than a threshold based on the measurement result of the outside air temperature measurement unit 17. The threshold is, for example, between -5°C and 10°C, and preferably between 0°C and 5°C.

[0034] As a first process of anti-freeze control, the lower limit setting unit 51B determines a first lower limit value for the opening degree of the first valve V1 based on the flow rate of the first circulating water W1 supplied to the preheating coil 11 so that the flow rate of the first circulating water W1 flowing through the preheating coil 11 does not fall below the flow rate lower limit value.

[0035] For example, when it is determined that the outside air temperature is equal to or lower than the threshold, the lower limit setting unit 51B acquires the flow rate of the first circulating water W1 measured by the first flow rate measuring unit 21 and the opening degree of the first valve V1 at the time when the first flow rate measuring unit 21 measured the flow rate of the first circulating water W1. Then, the lower limit setting unit 51B specifies a first lower limit value of the opening degree of the first valve V1 from the correspondence relationship between the flow rate of the first circulating water W1 and the opening degree of the first valve V1 at the time when the flow rate is measured, so that the flow velocity of the first circulating water W1 flowing through the preheating coil 11 does not fall below the flow velocity lower limit value.

[0036] At this time, the lower limit setting unit 51B uses the flow rate information stored in the flow rate information memory unit 52A to determine the first lower limit value of the opening degree of the first valve V1 from the correspondence between the flow rate of the first circulating water W1 and the opening degree of the first valve V1.

[0037] The correspondence relationship between the flow rate of the first circulating water W1 and the opening degree of the first valve V1 varies depending on, for example, the water pressure (output of the pump 41) of the first circulating water W1 supplied to the preheating coil 11. Therefore, the lower limit setting unit 51B may calculate the opening degree of the first valve V1 when the flow velocity of the first circulating water W1 flowing through the preheating coil 11 reaches the flow velocity lower limit value based on the amount of change in the flow rate of the first circulating water W1 relative to the amount of change in the opening degree of the first valve V1.

[0038] As a second process of anti-freeze control, the lower limit setting unit 51B determines a second lower limit value for the opening degree of the first valve V1 based on the water temperature of the first circulating water W1 that has passed through the preheating coil 11 so that the water temperature of the first circulating water W1 that has passed through the preheating coil 11 does not fall below the water temperature lower limit value.

[0039] For example, when it is determined that the outside air temperature is equal to or lower than the threshold value, the lower limit setting unit 51B acquires the water temperature of the first circulating water W1 measured by the first water temperature measuring unit 31 and the opening degree of the first valve V1 at the time when the first water temperature measuring unit 31 measured the water temperature of the first circulating water W1. Then, the lower limit setting unit 51B specifies a second lower limit value of the opening degree of the first valve V1 from the correspondence relationship between the water temperature of the first circulating water W1 and the opening degree of the first valve V1 at the time when the water temperature is measured so that the water temperature of the first circulating water W1 flowing through the preheating coil 11 does not fall below the water temperature lower limit value.

[0040] At this time, the lower limit setting unit 51B uses the water temperature information stored in the water temperature information memory unit 52B to determine a second lower limit value for the opening degree of the first valve V1 from the correspondence between the water temperature of the first circulating water W1 and the opening degree of the first valve V1.

[0041] The correspondence relationship between the water temperature of the first circulating water W1 and the opening degree of the first valve V1 varies depending on, for example, the water pressure of the first circulating water W1 supplied to the preheating coil 11. Therefore, the lower limit setting unit 51B may calculate the opening degree of the first valve V1 when the water temperature of the first circulating water W1 flowing through the preheating coil 11 reaches the water temperature lower limit value based on the amount of change in the water temperature of the first circulating water W1 relative to the amount of change in the opening degree of the first valve V1.

[0042] As an example, when it is determined that the outside air temperature is equal to or lower than the threshold during heating operation, the control unit 51 proportionally controls the opening degree of the first valve V1 within a range that does not fall below both the first and second lower limits. That is, the control unit 51 proportionally controls the opening degree of the first valve V1 so that the opening degree does not fall below the larger of the first and second lower limits.

[0043] The control unit 51 may proportionally control the opening degree of the first valve V1 within a range not falling below at least one of the first lower limit value and the second lower limit value. In other words, the control unit 51 may proportionally control the opening degree of the first valve V1 so as not to fall below the smaller of the first lower limit value and the second lower limit value.

[0044] The lower limit value setting unit 51B repeats the above-mentioned first process and second process at every arbitrary set time to update the first and second lower limits at every set time. As a result, even if the water pressure of the first circulating water W1 changes, the first and second lower limits corresponding to the change in water pressure are newly determined.

[0045] For example, depending on the temperature and air volume required for the temperature-controlled air CA1, the required opening value of the first valve V1 in proportional control may fall below the lower limit of the opening value of the first valve V1. In this case, the opening value of the first valve V1 becomes larger than the required value, and the outdoor air OA1 may become overheated. In such a case, the outdoor air OA1 heated by the preheating coil 11 is cooled by a cooling means such as the cooling coil 13 or the humidifier 16 located on the indoor side of the preheating coil 11, thereby adjusting the temperature of the temperature-controlled air CA1.

[0046] [Operation of the embodiment] When the air conditioner 10 is in heating operation and the outside air temperature is equal to or lower than a threshold value, the proportional control of the opening of the first valve V1 adjusts the opening of the first valve V1 so as not to fall below a first lower limit value specified based on the flow rate of the first circulating water W1 supplied to the preheating coil 11. This keeps the flow rate of the first circulating water W1 flowing through the preheating coil 11 at or above a predetermined flow rate lower limit value, thereby suppressing freezing of the first circulating water W1.

[0047] Furthermore, in proportional control of the opening of the first valve V1, the opening of the first valve V1 is adjusted so as not to fall below a second lower limit value determined based on the water temperature of the first circulating water W1. This keeps the water temperature of the first circulating water W1 flowing through the preheating coil 11 at or above a predetermined water temperature lower limit value, thereby suppressing freezing of the first circulating water W1.

[0048] [Effects of the embodiment] (1) In the above embodiment, when the outside air temperature is low, a lower limit is set for the opening of the first valve V1 based on the state information, which is a management parameter for preventing the first circulating water W1 from freezing. This keeps the flow rate and water temperature of the first circulating water W1 flowing through the preheating coil 11 in an appropriate state, thereby preventing the first circulating water W1 flowing through the preheating coil 11 from freezing.

[0049] Furthermore, compared to a conventional configuration in which a predetermined lower limit (constant value) is set for the valve opening, according to the above embodiment, even when the water pressure of the first circulating water W1 changes, a more appropriate lower limit for the opening can be set in accordance with the state information of the first circulating water W1. For example, when the water pressure of the first circulating water W1 is low, the lower limit for the opening of the first valve V1 is set relatively high, so that freezing of the first circulating water W1 can be more reliably prevented. For example, when the water pressure of the first circulating water W1 is high, the lower limit for the opening of the first valve V1 is set relatively low, so that the opening of the first valve V1 can be controlled over a wider range.

[0050] (2) In the anti-freeze control, the control unit 51 specifies a lower limit value of the opening degree of the first valve V1 in advance, and thereby a limiter is set to prevent the first circulating water W1 from reaching a water temperature or flow rate that would cause the first circulating water W1 to freeze in the proportional control of the opening degree of the first valve V1. Therefore, for example, freezing of the first circulating water W1 can be more reliably prevented compared to a control mode in which the flow rate is increased when the water temperature of the first circulating water W1 reaches a water temperature that would cause the first circulating water W1 to freeze.

[0051] (3) The control unit 51 adjusts the opening of the first valve V1 so that the flow rate of the first circulating water W1 supplied to the preheating coil 11 does not fall below a first lower limit value specified based on the flow rate of the first circulating water W1 supplied to the preheating coil 11. This makes it possible to maintain the flow rate of the first circulating water W1 flowing through the preheating coil 11 at a rate that prevents the first circulating water W1 from freezing.

[0052] (4) The control unit 51 adjusts the opening of the first valve V1 so that the water temperature does not fall below a second lower limit value determined based on the water temperature of the first circulating water W1 that has passed through the preheating coil 11. This makes it possible to keep the water temperature of the first circulating water W1 flowing through the preheating coil 11 at a temperature that will not cause the first circulating water W1 to freeze.

[0053] (5) The lower limit setting unit 51B specifies the lower limit of the opening degree of the first valve V1 based on the state information measured by the measurement unit when the heating operation is in progress and the outside air temperature is equal to or lower than the threshold. By performing anti-freeze control when the outside air temperature is low, the lower limit of the opening degree of the first valve V1 is not set when the outside air temperature is relatively high even during the heating operation, so that the opening degree of the first valve V1 can be controlled in a wider range.

[0054] (6) In the case where the required value of the opening degree of the first valve V1 falls below the lower limit value of the opening degree of the first valve V1, causing the outside air OA1 to be overheated, the outside air OA1 is cooled by a cooling means located on the indoor side of the preheating coil 11. This makes it possible to optimize the temperature of the temperature-controlled air CA1 while performing anti-freeze control.

[0055] [Example of change] This embodiment can be modified as follows: This embodiment and the following modifications can be combined with each other to the extent that there is no technical contradiction.

[0056] Although the configuration in which the anti-freeze control is performed when the heating operation is in progress and the outside air temperature is equal to or lower than the threshold has been exemplified, the present invention is not limited to this, and for example, the anti-freeze control may be performed at all times during the heating operation regardless of the outside air temperature. In this case, the outside air temperature measuring unit 17 and the determination unit 51A may be omitted.

[0057] The lower limit setting unit 51B may be configured to perform at least one of the first process and the second process of the anti-freeze control. In other words, the lower limit setting unit 51B may be configured to specify the lower limit of the opening degree of the first valve V1 based on at least one piece of state information. For example, the lower limit setting unit 51B may be configured to perform only the first process of the anti-freeze control. In this case, the first water temperature measuring unit 31 may be omitted. For example, the lower limit setting unit 51B may be configured to perform only the second process of the anti-freeze control. In this case, the first flow rate measuring unit 21 may be omitted.

[0058] The cooling means for cooling the overheated outside air OA1 may be omitted. The configuration of the air conditioner 10 is not limited to a configuration including coils 11-14, but may include at least one heat exchange coil. For example, the air conditioner 10 may include one heat exchange coil to which hot water is supplied during heating operation and cold water is supplied during cooling operation. In this case, the air conditioner 10 may include a cooling means other than a heat exchange coil, such as a humidifier 16.

[0059] When the air conditioner 10 includes a plurality of heat exchange coils as in the above embodiment, it is only necessary to perform control to specify the lower limit of the opening of the valve that adjusts the amount of circulating water supplied to at least the heat exchange coil located closest to the outdoors. Similar freezing control processing may also be performed for the other heat exchange coils.

[0060] [Note] According to the above embodiment and its modifications, the following technical ideas can be derived. [Appendix 1] An air conditioner that adjusts the temperature of the outside air and blows it indoors, A control unit that controls the air conditioner, The air conditioner is A coil to which circulating water is supplied during heating operation; a valve for adjusting the flow rate of the circulating water supplied to the coil; A measuring unit that measures status information of the circulating water supplied to the coil, The control unit, during the heating operation, identifies a lower limit value of the opening degree of the valve based on the state information measured by the measurement unit, and adjusts the opening degree so as not to fall below the lower limit value; The air conditioner further includes a cooling unit that cools the outside air that has become overheated when the required value of the opening degree falls below the lower limit value. Air conditioning system. [Explanation of symbols]

[0061] CA1...temperature-controlled air, H10...information processing device, H11...communication device, H12...input device, H13...display device, H14...storage device, H15...processor, OA1...outdoor air, V1...first valve, V2...second valve, V3...third valve, V4...fourth valve, W1...first circulating water, W2...second circulating water, W3...third circulating water, W4...fourth circulating water, 1...air conditioning system, 10...air conditioner, 11...preheating coil, 12...heating coil, 13...cooling coil, 14...reheating coil, 15 ...fan, 16...humidifier, 17...outdoor air temperature measurement unit, 21...first flow rate measurement unit, 22...second flow rate measurement unit, 23...third flow rate measurement unit, 24...fourth flow rate measurement unit, 31...first water temperature measurement unit, 32...second water temperature measurement unit, 33...third water temperature measurement unit, 34...fourth water temperature measurement unit, 40...heat source equipment, 41...pump, 50...control device, 51...control unit, 51A...judgment unit, 51B...lower limit value setting unit, 52...memory unit, 52A...flow rate information memory unit, 52B...water temperature information memory unit.

Claims

1. An air conditioner that adjusts the temperature of the outside air and blows it indoors, A control unit that controls the air conditioner, The air conditioner is A coil to which circulating water is supplied during heating operation; a valve for adjusting the flow rate of the circulating water supplied to the coil; A measuring unit that measures status information of the circulating water supplied to the coil, The control unit, during the heating operation, specifies a lower limit value of the opening degree of the valve based on the state information measured by the measurement unit, and adjusts the opening degree so that the opening degree does not fall below the lower limit value. Air conditioning system.

2. The air conditioner includes, as the measurement unit, a flow rate measurement unit that measures a flow rate of the circulating water supplied to the coil, The control unit specifies the lower limit value based on the flow rate measured by the flow rate measuring unit as the state information.

2. The air conditioning system of claim 1.

3. The air conditioner includes, as the measurement unit, a water temperature measurement unit that measures a temperature of the circulating water that has passed through the coil, The control unit specifies the lower limit value based on the water temperature measured by the water temperature measuring unit as the state information.

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

4. The control unit, when the heating operation is performed and the outside air temperature is equal to or lower than a threshold value, specifies the lower limit value based on the state information measured by the measurement unit.

2. The air conditioning system of claim 1.

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