Air conditioning system

Abstract

To reduce energy consumption of an air conditioner.SOLUTION: An air conditioner (100) includes a sensor (15) for acquiring an index related to a temperature of air in an object space (S), a first heat exchanger (25) for exchanging heat between air in an air passage (P) and a refrigerant, a heater (12) disposed in a downstream side of the first heat exchanger (25) in the air passage (P), a second heat exchanger (27) for exchanging heat between the air after passing through the first heat exchanger (25) and the refrigerant, and a control device (30). The control device (30) includes a first control unit (31) for controlling the heater (12) on the basis of the index, and a second control unit (32) for controlling the second heat exchanger (27) on the basis of an output target value of the heater (12) which is a value larger than 0.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present disclosure relates to an air conditioner.

Background Art

[0002] Patent Document 1 discloses a cooling device which is a type of refrigeration device. The cooling device of Patent Document 1 includes a refrigerant circuit in which a refrigerant circulates to perform a refrigeration cycle, a refrigerant heat circuit (refrigerant reheat circuit), a first utilization system which is a utilization side circuit, and a controller.

[0003] The refrigerant circuit has a compressor, a condenser, a receiver, and a first evaporator connected in sequence. One end of the refrigerant heat circuit is connected between the compressor and the condenser in the refrigerant circuit, and the other end is connected between the condenser and the receiver in the refrigerant circuit. A refrigerant reheat coil is provided in the refrigerant heat circuit. The first utilization system includes a casing through which air flows. Inside the casing, the first evaporator, the refrigerant reheat coil, and a heater are arranged in sequence from the upstream side of the air flow.

[0004] In the first evaporator, the refrigerant evaporates by exchanging heat with the air of the first utilization system, and the air is cooled. In the refrigerant reheat coil, the refrigerant condenses by exchanging heat with the air cooled by the first evaporator, and the air is heated. In the heater, the air whose temperature has been adjusted in sequence by the first evaporator and the refrigerant reheat coil is heated, and further temperature adjustment is performed.

[0005] In the first utilization system, the controller adjusts the opening degrees of the first expansion valve and the electric valve in the refrigerant circuit and adjusts the heating amount of the heater so that the air flowing through the first evaporator, the refrigerant reheat coil, and the heater finally reaches a predetermined temperature.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

[0007] In a refrigeration system (air conditioning system) like the one described in Patent Document 1, when heating air in the first utilization system, it is conceivable to individually adjust the opening degree of an electric valve for adjusting the temperature of the air passing through the refrigerant reheat coil and the amount of heating of the heater.

[0008] However, if the opening degree of the electric valve and the heating amount of the heater are adjusted separately, the ratio of the amount of heat generated by the refrigerant reheat coil to the amount of heat generated by the heater becomes arbitrary. As a result, there was a risk that more energy than necessary would be consumed in the air conditioning system, leading to poor energy efficiency.

[0009] The purpose of this disclosure is to reduce the energy consumption of air conditioning systems. [Means for solving the problem]

[0010] The first embodiment relates to an air conditioning system (100). The air conditioning system (100) includes a sensor (15) that acquires an index relating to the temperature of the air in a target space (S), a casing (11) having an intake port (11a) and an outlet port (11b) and having an air passage (P) formed between the intake port (11a) and the outlet port (11b), a first heat exchanger (25) that exchanges heat between the air in the air passage (P) and a refrigerant, a heater (12) positioned downstream of the first heat exchanger (25) in the air passage (P), a second heat exchanger (27) that exchanges heat between the air in the air passage (P) after it has passed through the first heat exchanger (25) and a refrigerant, and a control device (30). The control device (30) includes a first control unit (31) that controls the heater (12) based on the index, and a second control unit (32) that controls the second heat exchanger (27) based on an output target value of the heater (12) that is greater than 0.

[0011] In the first embodiment, the second control unit (32) controls the second heat exchanger (27) based on the output target value of the heater (12). Therefore, by setting a small output target value for the heater (12) and increasing the amount of air heated by the second heat exchanger (27), the amount of heating by the heater (12) can be reduced while keeping the temperature of the air supplied to the target space (S) at the target temperature. As a result, the energy consumption of the air conditioning system (100) can be reduced.

[0012] In the second embodiment, the control device (30) determines whether or not the second control unit (32) controls the second heat exchanger (27) based on the temperature of the air after it has passed through the first heat exchanger (25).

[0013] In the second embodiment, for example, if the temperature of the air after passing through the first heat exchanger (25) is lower than the condensation temperature of the first heat exchanger (25), the second heat exchanger (27) can be controlled to reduce the energy consumption of the air conditioning system (100).

[0014] A third embodiment is the first or second embodiment, wherein the indicator is the temperature of the air blown out from the outlet (11b).

[0015] In the third embodiment, the heater (12) is controlled based on the temperature of the air blown out from the outlet (11b).

[0016] A fourth embodiment comprises a refrigerant circuit (20) filled with a refrigerant in any one of the first to third embodiments, the refrigerant circuit (20) having a first heat exchanger (25) and a second heat exchanger (27).

[0017] In the fourth embodiment, the first heat exchanger (25) and the second heat exchanger (27) are provided in a single refrigerant circuit.

[0018] The fifth aspect is that in any one of the first to third aspects, it includes a first refrigerant circuit (20) filled with a refrigerant and a second refrigerant circuit of a different system from the first refrigerant circuit, the first refrigerant circuit has the first heat exchanger (25), and the second refrigerant circuit has the second heat exchanger (27).

[0019] In the fifth aspect, the first heat exchanger (25) and the second heat exchanger (27) are provided in refrigerant circuits of different systems respectively.

Brief Description of Drawings

[0020] [Figure 1] FIG. 1 is a longitudinal sectional view showing a schematic configuration of an air conditioner according to an embodiment. [Figure 2] FIG. 2 is a piping system diagram of a refrigerant circuit provided in the air conditioner. [Figure 3] FIG. 3 is a block diagram showing the configuration of the air conditioner. [Figure 4] FIG. 4 is a flowchart showing the control of the heating amount.

Modes for Carrying Out the Invention

[0021] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. Note that the present disclosure is not limited to the embodiments shown below, and various modifications are possible without departing from the technical idea of the present disclosure. Since each drawing is for conceptually explaining the present disclosure, dimensions, ratios, or numbers may be exaggerated or simplified as necessary for easy understanding.

[0022] (1) Air conditioner The air conditioner (100) is a device that conditions the air in the target space (S). The air conditioner (100) of the present embodiment is a variable constant temperature and humidity air conditioner that can precisely control the temperature and humidity of the target space (S) within a wide range. The air conditioner (100) of the present embodiment is installed, for example, in an environmental test chamber where strict temperature and humidity management is required.

[0023] As shown in Figure 1, the air conditioning system (100) comprises a housing (10), a casing (11), a refrigerant circuit (20), an electric heater (12), a humidifier (13), a blower fan (14), a temperature sensor (15), a humidity sensor (16), and a control device (30).

[0024] (1-1) Cabinet The housing (10) is constructed as a rectangular box shape that is long in the vertical direction. The housing (10) houses a casing (11), a refrigerant circuit (20), an electric heater (12), a humidifier (13), a blower fan (14), a temperature sensor (15), a humidity sensor (16), and a control device (30). The casing (11) is positioned on the front side of the housing (10). A housing space (H) for housing the equipment of the air conditioning unit (100) is formed on the rear side of the housing (10). The housing space (H) is formed behind the casing (11).

[0025] (1-2) Casing The casing (11) is formed in the shape of a rectangular box that is elongated in the vertical direction. The casing (11) is fitted into the front of the housing (10). The front of the casing (11) faces the target space (S). An intake port (11a) and an outlet port (11b) are formed on the front of the casing (11).

[0026] The intake port (11a) is an opening for drawing in air from the target space (S). The intake port (11a) is formed at the lower front of the casing (11). The outlet port (11b) is an opening for blowing air into the target space (S). The outlet port (11b) is formed at the upper front of the casing (11). The intake port (11a) and the outlet port (11b) are formed in a horizontally elongated rectangular shape.

[0027] An air passage (P) is formed inside the casing (11). The air passage (P) is a space that extends vertically. The air passage (P) is formed between the intake port (11a) and the outlet port (11b). Therefore, air in the target space (S) flows in from the intake port (11a), flows upward through the air passage (P), and flows out from the outlet port (11b).

[0028] (1-3) Refrigerant Circuit The air conditioning system (100) includes one refrigerant circuit (20). The refrigerant circuit (20) is filled with refrigerant. The refrigerant circuit (20) performs a vapor compression type refrigeration cycle by circulating the refrigerant. As shown in Figure 2, the refrigerant circuit (20) includes a main circuit (20a) and a refrigerant reheat circuit (20b).

[0029] The main circuit (20a) includes a compressor (21), a condenser (22), a receiver (23), an expansion valve (24), an evaporator (25), and an accumulator (26). In the main circuit (20a), the compressor (21), condenser (22), receiver (23), expansion valve (24), evaporator (25), and accumulator (26) are connected in this order by connecting piping.

[0030] As shown in Figure 1, the compressor (21), condenser (22), receiver (23), expansion valve (24), and accumulator (26) are located at the bottom of the containment space (H). The evaporator (25) is located upstream of the air passage (P).

[0031] In a refrigeration cycle, the refrigerant compressed by the compressor (21) dissipates heat to the cooling medium in the condenser (22). The cooling medium is, for example, air or water. The refrigerant that has dissipated heat is depressurized by the expansion valve (24) and evaporates in the evaporator (25). The evaporated refrigerant is drawn back into the compressor (21).

[0032] The compressor (21) compresses the inhaled refrigerant and discharges the compressed refrigerant. The compressor (21) is, for example, a fully enclosed, high-pressure dome-type scroll compressor. The compressor (21) is inverter-type. The rotational speed (operating frequency) of the motor of the compressor (21) is adjusted by a control circuit.

[0033] The condenser (22) exchanges heat between the refrigerant flowing inside it and the cooling medium (for example, outside air).

[0034] The expansion valve (24) is an expansion mechanism. The expansion valve (24) reduces the pressure of the refrigerant. In this embodiment, the expansion valve (24) is an electronically controlled expansion valve whose opening degree is adjustable.

[0035] The evaporator (25) corresponds to the first heat exchanger of this disclosure. The evaporator (25) is a fin-and-tube type heat exchanger. The evaporator (25) exchanges heat between the refrigerant flowing inside it and the air in the target space (S). The evaporator (25) cools the air.

[0036] The refrigerant reheat circuit (20b) is connected to the main circuit (20a). The inlet end of the refrigerant reheat circuit (20b) is connected between the compressor (21) and the condenser (22). The outlet end of the refrigerant reheat circuit (20b) is connected between the condenser (22) and the receiver (23).

[0037] The refrigerant reheat circuit (20b) includes a reheater (27) and a reheat electric valve (28). As shown in Figure 2, in the refrigerant reheat circuit (20b), the reheater (27) and the reheat electric valve (28) are connected in order from the upstream side by connecting piping.

[0038] The reheater (27) corresponds to the second heat exchanger of this disclosure. The reheater (27) is a fin-and-tube type heat exchanger. As shown in Figure 2, a portion of the refrigerant discharged from the compressor (21) flows into the reheater (27). As shown in Figure 1, the reheater (27) is located downstream of the evaporator (25) in the air passage (P). The reheater (27) exchanges heat between the refrigerant flowing inside it and the air in the air passage (P) after it has passed through the evaporator (25). The reheater (27) functions as a condenser and heats the air.

[0039] The reheat electric valve (28) is used to adjust the amount of heat supplied to the air in the reheater (27). The reheat electric valve (28) is a flow control valve whose opening degree is adjustable. In the refrigerant reheat circuit (20b), when the opening degree of the reheat electric valve (28) decreases, the proportion of condensed liquid refrigerant in the reheater (27) increases, and the proportion of condensing gaseous refrigerant decreases. Therefore, in the refrigerant reheat circuit (20b), when the opening degree of the reheat electric valve (28) decreases, the amount of heat exchanged between the gaseous refrigerant and the air (heat of condensation) decreases, and the amount of heat supplied to the air decreases.

[0040] (1-4) Electric heater The electric heater (12) corresponds to the heater of this disclosure. As shown in Figure 1, the electric heater (12) of this embodiment is located downstream of the reheater (27) in the air passage (P). The electric heater (12) heats the air after it has passed through the reheater (27). The electric heater (12) further heats the air that has been temperature-controlled in the order of the evaporator (25) and the reheater (27) to control its temperature.

[0041] The electric heater (12) is formed in a horizontal shape. The electric heater (12) is positioned along the cross-section of the air passage (P). The electric heater (12) is positioned at least downstream of the evaporator (25) in the air passage (P). In other words, the electric heater (12) may be positioned between the evaporator (25) and the reheater (27) in the air passage (P).

[0042] (1-5) Humidifier The humidifier (13) adjusts the humidity of the air by adding water vapor to the air whose temperature has been controlled by the electric heater (12). The humidifier (13) has a main body (13a) and a nozzle (13b).

[0043] The main body (13a) is positioned approximately in the center of the containment space (H). The main body (13a) generates steam, for example, by heating water stored in an open container with a heater. The nozzle (13b) has its inlet connected to the main body (13a) and guides the steam generated in the main body (13a) into the air passage (P). The nozzle (13b) is positioned across the containment space (H) and the air passage (P). The outlet of the nozzle (13b) is positioned downstream of the electric heater (12) in the air passage (P).

[0044] (1-6) Blower fan The blower fan (14) transports air in the air passage (P). More specifically, the blower fan (14) draws air into the air passage (P), and after temperature and humidity control, discharges the air towards the target space (S). The blower fan (14) is positioned downstream of the nozzle (13b) of the humidifier (13) in the air passage (P).

[0045] The blower fan (14) is a propeller-type fan. The blower fan (14) may also be a turbo-type or sirocco-type fan. The motor (14a) of the blower fan (14) is an AC fan motor whose rotational speed is adjusted by a control circuit. The motor (14a) is located in the housing space (H).

[0046] (1-7) Temperature sensor, humidity sensor The temperature sensor (15) corresponds to the sensor of this disclosure. The temperature sensor (15) acquires an index of the air temperature in the target space (S). The temperature sensor (15) of this embodiment acquires the temperature of the air blown out from the outlet (11b).

[0047] The humidity sensor (16) acquires an index of the humidity of the air in the target space (S). In this embodiment, the humidity sensor (16) acquires the humidity of the air blown out from the outlet (11b). The temperature sensor (15) and the humidity sensor (16) are arranged near the outlet (11b) in the air passage (P).

[0048] (1-8) Control device The control device (30) adjusts the opening of the expansion valve (24) and the reheat electric valve (28) of the refrigerant circuit (20) and adjusts the amount of heating from the electric heater (12) so that the air that has flowed through the evaporator (25), reheater (27), and electric heater (12) eventually reaches a predetermined temperature.

[0049] The control unit (30) includes an MCU (Micro Control Unit), electrical circuits, and electronic circuits. The MCU includes a CPU (Central Processing Unit), memory, and a communication interface. The memory stores various programs for the CPU to execute.

[0050] As shown in Figure 3, the control device (30) controls the compressor (21), expansion valve (24), blower fan (14), reheat electric valve (28), electric heater (12), and humidifier (13). The control device (30) receives the values ​​obtained from the temperature sensor (15) and humidity sensor (16).

[0051] The control device (30) includes a first control unit (31) and a second control unit (32). The first control unit (31) controls the electric heater (12) based on the temperature of the air blown out from the outlet (11b). The second control unit (32) controls the reheater (27) based on the output target value of the electric heater (12). Specifically, the second control unit (32) controls the opening degree of the reheat electric valve (28) based on the output target value of the electric heater (12) so that the amount of heating in the reheater (27) is optimized.

[0052] Here, the target output value of the electric heater (12) is greater than 0. Therefore, when the second control unit (32) controls the opening degree of the reheat electric valve (28), the electric heater (12) will always operate.

[0053] The air conditioning unit (100) has a memory unit (33). The memory unit (33) stores in advance the target output value of the electric heater (12). The target output value of the electric heater (12) stored in the memory unit (33) differs depending on the set temperature of the air blown out from the outlet (11b). In other words, the memory unit (33) stores a table showing the set temperature and the target output value of the electric heater (12) for each set temperature. The set temperature is the target temperature of the target space (S) set by the user.

[0054] (2) Operating The operation of the air conditioning system (100) will be explained.

[0055] When the air conditioning system (100) is activated, the control device (30) operates the compressor (21) and the blower fan (14). The control device (30) adjusts the opening of the expansion valve (24) and the reheat electric valve (28), adjusts the heating amount of the electric heater (12), and adjusts the humidification amount of the humidifier (13) according to the set temperature and set humidity. The set humidity is the target humidity of the target space (S) set by the user.

[0056] In the air conditioning unit (100), when the blower fan (14) is operated, air from the target space (S) is drawn into the air passage (P) via the intake port (11a). The air flowing into the air passage (P) passes through the evaporator (25), reheater (27), electric heater (12), and humidifier (13) in that order. Specifically, the air flowing into the air passage (P) is cooled and dehumidified in the evaporator (25). The air cooled in the evaporator (25) is heated by the reheater (27). The air heated in the reheater (27) is further heated by the electric heater (12). The air heated by the electric heater (12) is humidified by the addition of moisture in the humidifier (13). The air humidified in the humidifier (13) is supplied to the target space (S) via the outlet (11b).

[0057] (3) Challenges of air conditioning systems Here, while electric heaters offer high temperature control responsiveness, they also consume a lot of energy. Therefore, in an air conditioning system (100) that does not have a reheater, the power consumption of the electric heater accounts for a large proportion of the total power consumption of the air conditioning system, increasing the power consumption of the air conditioning system.

[0058] In contrast, air conditioning systems equipped with reheaters instead of electric heaters can reduce power consumption because the reheaters utilize the condensation heat of the refrigeration cycle. However, because reheaters have poor temperature control responsiveness, such air conditioning systems take time to reach the set temperature. In particular, it is difficult to adjust the temperature within the required accuracy in air conditioning systems for variable temperature and humidity control, which require precise control.

[0059] Therefore, by providing a reheater (27) in addition to the electric heater (12), as in the air conditioning system (100) of this embodiment, it is conceivable that the amount of heating required by the electric heater (12) can be reduced, thereby saving power in the air conditioning system (100).

[0060] However, if the heating amount of the electric heater (12) and the heating amount of the reheater (27) are controlled individually without relating them to each other, the ratio of the heating amounts of the two will be random, potentially leading to the consumption of more energy than necessary and reducing the energy efficiency of the air conditioning system.

[0061] (4) Control of heating amount To solve the above problems, the air conditioning system (100) of this embodiment performs control to adjust the heating amount of the reheater (27) considering the heating amount of the electric heater (12). This control will be explained in detail with reference to Figure 4.

[0062] As shown in Figure 4, in step S1, the user sets a target value (set temperature) for the temperature of the air blown out from the outlet (11b) of the air conditioner (100).

[0063] In step S2, the control device (30) determines whether the first condition for the second control unit (32) to control the reheater (27) is met, based on the temperature of the air after passing through the evaporator (25). The first condition is that the temperature of the air after passing through the evaporator (25) is lower than the condensation temperature of the reheater (27).

[0064] If the first condition is not met in step S2, the process proceeds to step S3. Steps S3 to S5 are processes performed when the first condition is not met. Here, the first condition is not met when the temperature of the air after passing through the evaporator (25) is equal to or higher than the condensation temperature of the reheater (27). In this case, the reheater (27) cannot heat the air after passing through the evaporator (25). Therefore, in steps S3 to S5, the air after passing through the evaporator (25) is heated only by the electric heater (12) without using the reheater (27).

[0065] In step S3, the temperature sensor (15) detects the outlet temperature and transmits it to the control device (30). The control device (30) acquires the outlet temperature.

[0066] Next, in step S4, the control device (30) calculates a control value for controlling the electric heater (12) based on the acquired outlet temperature and set temperature. Specifically, the control device (30) calculates the amount of heating for the electric heater (12) based on the difference between the acquired outlet air temperature and the set temperature. The control device (30) calculates a control value for the electric heater (12) based on the calculated amount of heating. In this embodiment, the control value for the electric heater (12) is expressed as a ratio to the rated output of the electric heater (12). For example, if the rated output of the electric heater (12) is 40 kW and the amount of heating calculated by the control device (30) is 20 kW, the control device (30) calculates a control value of 50%.

[0067] Next, in step S5, the control device (30) outputs a control value to the electric heater (12). In this way, if the first condition is not met in step S2, the air after passing through the evaporator (25) is heated only by the electric heater (12).

[0068] In step S2, if the first condition is met, the process proceeds to step S6. The first condition is met when the temperature of the air after passing through the evaporator (25) is lower than the condensation temperature of the reheater (27). In this case, the air after passing through the evaporator (25) can be heated in the reheater (27). Therefore, from step S6 to step S12, the air after passing through the evaporator (25) is heated by the reheater (27) and the electric heater (12).

[0069] In step S6, similar to step S3, the temperature sensor (15) detects the outlet temperature and transmits it to the control device (30). The control device (30) acquires the outlet temperature.

[0070] Next, in step S7, the control device (30) calculates the amount of heating when only the electric heater (12) is operated based on the difference between the acquired discharge temperature and the set temperature, and calculates the control value of the electric heater (12) when only the electric heater (12) is operated based on the calculated amount of heating. Here, "when only the electric heater (12) is operated" means when the air is heated by the electric heater (12) alone without heating the air by the reheater (27).

[0071] Following step S7, the control of the electric heater (12), which is performed by the processes from step S8 to step S10, and the control of the reheat electric valve (28), which is performed by the processes from step S11 to step S13, are carried out in parallel.

[0072] The process from step S8 to step S10, which controls the electric heater (12), is the same as the process from step S3 to step S5.

[0073] In controlling the reheat electric valve (28), first in step S11, the control device (30) obtains the target output value of the electric heater (12) according to the set temperature from the storage unit (33). The target output value of the electric heater (12) here is expressed as a ratio to the rated output of the electric heater (12).

[0074] Next, in step S12, the control device (30) calculates the opening degree of the reheat electric valve (28) for controlling the reheater (27) based on the output target value of the electric heater (12). Specifically, the control device (30) calculates the opening degree of the reheat electric valve (28) such that the amount of heating of the reheater (27) corresponds to the amount of heating of the electric heater (12) based on the difference ΔR between the control value of the electric heater (12) when only the electric heater (12) is operated, which was calculated in step S7, and the output target value of the electric heater (12). The opening degree of the reheat electric valve (28) here is expressed as the percentage of opening when the fully open state of the reheat electric valve (28) is taken as 100%.

[0075] Next, in step S13, the control device (30) outputs the calculated opening degree to the reheat electric valve (28). As a result, an amount of heat equivalent to the difference ΔR is imparted to the air passing through the reheater (27).

[0076] In this way, the amount of heat equivalent to the difference ΔR is imparted to the air passing through the reheater (27), and as a result, the output of the electric heater (12) becomes equal to the target output value of the electric heater (12). Consequently, when heating air using both the electric heater (12) and the reheater (27), the amount of heat generated by the electric heater (12) is reduced compared to when heating air using only the electric heater (12).

[0077] As described above, the air in the air passage (P) after passing through the reheater (27) and electric heater (12) is adjusted to the set temperature. At this time, the reheater (27) is controlled based on the output target value of the electric heater (12), so by setting a small output target value for the electric heater (12) and maximizing the heating capacity of the reheater (27), the overall energy consumption of the air conditioning system can be reduced.

[0078] (5) Characteristics (5-1) The control device (30) of the air conditioning system (100) includes a first control unit (31) that controls the electric heater (12) based on an index relating to the air temperature of the target space (S), and a second control unit (32) that controls the reheater (27) based on an output target value of the electric heater (12) that is greater than 0.

[0079] Therefore, by setting a lower output target value for the electric heater (12) and relatively increasing the amount of air heated by the reheater (27), the amount of heating by the electric heater (12) can be reduced while maintaining the target temperature of the air supplied to the target space (S). As a result, the energy consumption of the air conditioning system (100) can be reduced.

[0080] (5-2) The control device (30) determines whether or not the second control unit (32) controls the reheater (27) based on the temperature of the air after it has passed through the evaporator (25). Therefore, if the temperature of the air after it has passed through the evaporator (25) is lower than the condensation temperature of the reheater (27), the energy consumption of the air conditioning system (100) can be reduced by controlling the reheater (27).

[0081] (5-3) In this embodiment, the indicator for the temperature of the air in the target space (S) is the temperature of the air blown out from the outlet (11b). As a result, the electric heater (12) is controlled based on the temperature of the air blown out from the outlet (11b).

[0082] (5-4) The air conditioning system (100) comprises one refrigerant circuit (20) filled with refrigerant. The refrigerant circuit (20) has an evaporator (25) and a reheater (27). Thus, the evaporator (25) and the reheater (27) are provided in one refrigerant circuit (20).

[0083] (6) Variant The above embodiment may also be modified as follows. In the following description, we will primarily explain the differences from the above embodiment.

[0084] (6-1) Torture 1 In the air conditioning system (100) of this embodiment, the index for the temperature of the air in the target space (S) may be the temperature of the air in the target space (S). Specifically, a temperature sensor may be installed in the target space (S), and the detected value of the set temperature sensor may be used as the index for the temperature of the air in the target space (S).

[0085] (6-2) Modification 2 In the air conditioning system (100) of this embodiment, the control device (30) does not need to determine whether the first condition is met. In this case, the processes from step S3 to step S5 are not performed as part of the heating amount control. In other words, in this case, only the processes from step S6 to step S13 are performed as part of the heating amount control.

[0086] (6-3) Modification example 3 The air conditioning system (100) of this embodiment may have two refrigerant circuits. Specifically, the air conditioning system (100) includes a first refrigerant circuit and a second refrigerant circuit into which refrigerant is filled. The first refrigerant circuit and the second refrigerant circuit are independent of each other and are refrigerant circuits of different systems. The first refrigerant circuit has an evaporator (25), and the second refrigerant circuit has a reheater (27). As a result, the evaporator (25) and the reheater (27) are provided in separate refrigerant circuits, making it easier to control each of them.

[0087] (6-4) Modification 4 The air conditioning system (100) of this embodiment does not necessarily have to include a humidifier (13). In this case, the air conditioning system (100) is a device that adjusts the temperature of the target space (S).

[0088] Although embodiments and modifications have been described above, it will be understood that various changes in form and details are possible without departing from the spirit and scope of the claims. Furthermore, elements of the above embodiments, modifications, and other embodiments may be combined or substituted as appropriate.

[0089] The designations "1st," "2nd," "3rd," etc., mentioned above are used to distinguish between the terms to which these designations are attached, and do not limit the number or order of those terms. [Industrial applicability]

[0090] As explained above, this disclosure is useful for air conditioning systems. [Explanation of Symbols]

[0091] 11 Casing 11a Inlet 11b Air outlet 12 Electric heater (heater) 15. Temperature sensor (sensor) 20 Refrigerant Circuit 25. Evaporator (First Heat Exchanger) 27 Reheater (second heat exchanger) 30 Control device 31 First Control Unit 32 Second Control Unit 100 Air conditioning system P Air passage S Target space

Claims

1. A sensor (15) that acquires an index of the air temperature in the target space (S), A casing (11) having an inlet (11a) and an outlet (11b), with an air passage (P) formed between the inlet (11a) and the outlet (11b), A first heat exchanger (25) that exchanges heat between the air in the aforementioned air passage (P) and the refrigerant, A heater (12) is located downstream of the first heat exchanger (25) in the air passage (P), A second heat exchanger (27) in which the air in the air passage (P) after passing through the first heat exchanger (25) exchanges heat with the refrigerant, The system includes a control device (30), The control device (30) is A storage unit (33) that stores the set temperature, which is the target value of the aforementioned indicator, and the output target value of the heater (12) corresponding to the set temperature, A first control unit (31) controls the heater (12) based on the aforementioned indicator, The system includes a second control unit (32) that controls the second heat exchanger (27) based on an output target value of the heater (12) which is greater than 0, The second control unit (32) is: The output target value of the heater (12) corresponding to the set temperature is obtained from the storage unit (33), Based on the difference between the set temperature and the index, the amount of heating when the air is heated by the heater (12) alone is calculated, and based on the calculated amount of heating, the control value of the heater (12) is calculated. The difference ΔR between the calculated control value of the heater (12) and the output target value of the heater (12) obtained from the storage unit (33) is calculated. The amount of heating in the second heat exchanger (27) is set to an amount of heating equivalent to the difference ΔR in the heater (12). Air conditioning system.

2. The control device (30) determines whether or not the second control unit (32) controls the second heat exchanger (27) based on the temperature of the air after it has passed through the first heat exchanger (25). The air conditioning device according to claim 1.

3. The aforementioned index is the temperature of the air blown out from the outlet (11b). The air conditioning device according to claim 1 or 2.

4. It is equipped with one refrigerant circuit (20) filled with refrigerant, The refrigerant circuit (20) includes the first heat exchanger (25) and the second heat exchanger (27). The air conditioning device according to claim 1 or 2.

5. It comprises a first refrigerant circuit filled with refrigerant and a second refrigerant circuit that is a different system from the first refrigerant circuit, The first refrigerant circuit includes the first heat exchanger (25), The second refrigerant circuit has the second heat exchanger (27) The air conditioning device according to claim 1 or 2.

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