JP6392834B2 - Air conditioner - Google Patents

Description

    The present invention relates to an air conditioner.

    Conventionally, an air conditioner that adjusts the temperature of air in a target space such as a room is widely known.

    For example, in the air conditioner disclosed in Patent Document 1, a cooling coil is disposed in an air passage through which air flows. A flow path (path) through which the cooling medium flows is formed inside the cooling coil. In the cooling coil, the cooling medium and air exchange heat, and the air is cooled. The cooled air is supplied to a target space such as a room.

JP 2010-243004 A

    By the way, there is a test facility for cooling the air in the test room by the air conditioner as described above. That is, in this test facility, a refrigeration apparatus, which is a device under test, is arranged in a test room, and the air conditioner maintains the air in the test room at a predetermined temperature. Thereby, test data such as the performance of the refrigeration apparatus can be obtained while adjusting the temperature atmosphere around the refrigeration apparatus.

    On the other hand, when the air in the test chamber is cooled to a relatively low temperature in the air conditioner, moisture in the air may adhere to the surface of the cooling coil and frost may occur. Therefore, it is conceivable to perform a defrosting operation for defrosting the cooling coil in the air conditioner. That is, in the defrost operation, frost on the surface of the cooling coil is melted by heat. Thereby, the cooling coil can be defrosted and the cooling performance of the cooling coil can be recovered.

    However, when the defrosting operation of the cooling coil is performed, heat for melting the frost is also released into the air, so that the air temperature in the test chamber rises. When the air temperature in the test chamber rises in this way, the ambient temperature of the refrigeration apparatus, which is a device under test, temporarily rises, so that a desired test environment cannot be maintained. As a result, in such a period, there is a problem that the test data of the refrigeration apparatus cannot be detected accurately and the test time is prolonged.

    The present invention has been made in consideration of such points, and the purpose of the present invention is to reduce the substantial test time of the refrigeration apparatus, which is a machine under test, with the defrosting of the cooling coil. It is to suppress.

    The first invention is directed to an air conditioner for a test chamber (2) in which an evaporator (4) of a refrigeration apparatus (A), which is a machine under test, is disposed, and cooling that cools air with a cooling medium. The coil (21) and the refrigeration apparatus (A) perform the defrosting operation on the coil side for defrosting the cooling coil (21) in conjunction with the defrosting operation on the evaporator side for defrosting the evaporator (4). And a controller (70) to be executed.

    In the first aspect of the invention, when frost forms on the evaporator (4) of the refrigeration system (A) that is the machine under test, the evaporator (4) is used to melt the frost on the surface of the evaporator (4). A defrost operation (evaporator side defrost operation) is performed. Thereby, since the frost of the evaporator (4) is melted, the evaporation performance of the evaporator (4) can be recovered.

    In the present invention, the defrosting operation (coil side defrosting operation) of the cooling coil (21) is performed in conjunction with the evaporator side defrosting operation. In other words, if the evaporator-side defrosting operation and the coil-side defrosting operation are executed at different times, not only during the evaporator-side defrosting operation but also during the coil-side defrosting operation, the performance evaluation of the evaporator (4) is performed. It will not be accurate. This is because the air temperature in the test chamber (2) temporarily rises due to the coil-side defrost operation. On the other hand, if the evaporator-side defrosting operation and the coil-side defrosting operation are executed at the same timing, the air temperature in the test chamber (2) only increases in accordance with the defrosting timing of the evaporator (4). . Thereby, when the evaporator side defrost operation | movement is not performed, it can suppress that air temperature raises resulting from the defrost of a cooling coil (21).

    A second invention is characterized in that, in the first invention, the controller (70) causes the coil side defrost operation to be executed each time the evaporator side defrost operation reaches a predetermined number of times. To do.

    In the second invention, every time the evaporator-side defrost operation is executed a plurality of times, the coil-side defrost operation is executed. That is, the coil-side defrost operation is not executed for each evaporator-side defrost operation. For this reason, since the execution frequency of coil side defrost operation | movement can be reduced, the raise of the air temperature resulting from the defrost of a cooling coil (21) can be suppressed.

    According to a third invention, in the first or second invention, the first setting for executing the defrosting operation on the coil side in conjunction with the defrosting operation on the evaporator side, and the defrosting operation on the evaporator side. A setting unit (73) capable of switching between the second setting for prohibiting execution of the coil side defrosting operation is provided.

    In the third aspect of the invention, when the setting unit (73) is set to the first state, the coil-side defrost operation is executed in conjunction with the evaporator-side defrost operation. On the other hand, when the setting unit (73) is set to the second state, the coil side defrost operation is not executed in conjunction with the evaporator side defrost operation. Therefore, by setting the setting unit (73) to the second state, execution of the coil-side defrost operation itself can be prohibited, and an increase in air temperature can be reliably prevented.

    According to a fourth invention, in any one of the first to third inventions, the controller (70) outputs an output signal output from the refrigeration apparatus (A) in conjunction with the defrost operation on the evaporator side. Is received, the defrosting operation on the coil side is executed.

    In the fourth aspect of the invention, when the evaporator-side defrost operation is executed, the output signal from the refrigeration apparatus (A) is received by the controller (70) of the air conditioner (10). When this output signal is received, the controller (70) performs a coil-side defrost operation. Thereby, the coil side defrost can be reliably executed in accordance with the execution timing of the evaporator side defrost.

    A fifth aspect of the present invention is the evaporator fan (25) according to any one of the first to third aspects, wherein the refrigeration apparatus (A) is stopped when a defrost operation on the evaporator side is executed. And a wind speed sensor (17) for detecting the wind speed of the evaporator fan (25), and the controller (70) is configured such that when the wind speed detected by the wind speed sensor (17) falls below a predetermined value, the coil The defrosting operation on the side is executed.

    In the fifth aspect of the invention, when the evaporator-side defrost operation is executed and the evaporator fan (25) is stopped, the wind speed value detected by the wind speed sensor (17) becomes a predetermined value or less. When this condition is satisfied, the controller (70) determines that the evaporator-side defrost operation has been executed, and causes the coil-side defrost operation to be executed.

    In the first aspect of the invention, since the coil side defrost operation is executed in conjunction with the evaporator side defrost operation, air is caused by defrosting of the cooling coil (21) during the period when the evaporator side defrost operation is not executed. An increase in temperature can be avoided. Thereby, the time which can maintain the circumference | surroundings of an evaporator (4) in desired temperature atmosphere becomes long, and can extend the substantial test time of a freezing apparatus (A) by extension.

    In particular, in the second and third inventions, the frequency of execution of the coil-side defrost operation can be reduced, so that the increase in the air temperature of the test chamber (2) due to the defrosting of the cooling coil (21) is suppressed. it can. As a result, the substantial test time of the refrigeration apparatus (A) can be further prolonged.

FIG. 1 is a schematic overall configuration diagram of an air-conditioning apparatus according to an embodiment. FIG. 2 is a schematic overall configuration diagram of the air-conditioning apparatus according to the embodiment, for explaining a pull-down operation or a normal operation (when the cooling load is relatively high). FIG. 3 is a schematic overall configuration diagram of the air-conditioning apparatus according to the embodiment, and is for explaining a cooling operation in a normal operation (when the cooling load is relatively low) or a pre-cooling operation. FIG. 4 is a schematic overall configuration diagram of the air-conditioning apparatus according to the embodiment, and is for explaining a coil-side defrost operation. FIG. 5 is a schematic overall configuration diagram of an air-conditioning apparatus according to Modification 1, and is for explaining a coil-side defrost operation.

    Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The following embodiments are essentially preferable examples, and are not intended to limit the scope of the present invention, its application, or its use.

    The air conditioner (10) of this embodiment adjusts the temperature of the air in the test room (2) that is the target space. The air conditioner (10) also has a humidity control function for adjusting the humidity of the test chamber (2).

<Overall configuration of test equipment>
The air conditioner (10) of this embodiment is applied to the test facility (1) shown in FIG. The test facility (1) is for evaluating the performance and the like of an air conditioner (a unit under test side air conditioner (A)) as a test target. In the test room (2), the outdoor unit (3) of the unit under test air conditioner (A) is installed as a test target (machine under test). In the test room (2), the ambient environment (temperature and humidity environment) of the outdoor unit (3) can be simulated. In the test chamber (2) of the present embodiment, a temperature atmosphere below freezing from 0 ° C. to −15 ° C. can be reproduced in order to reproduce a cold region.

    An outdoor heat exchanger (4) and an outdoor fan (6) are accommodated inside the casing of the outdoor unit (3). The unit under test air conditioner (A) comprises a refrigerant circuit to which a compressor, an outdoor heat exchanger (4), an expansion valve, and an indoor heat exchanger are connected, and constitutes a refrigeration system that performs a vapor compression refrigeration cycle doing. The unit under test air conditioner (A) can execute a defrosting operation for melting frost attached to the outdoor heat exchanger (4) serving as an evaporator (details will be described later).

    As shown in FIG. 1, the test facility (1) is configured so that air circulates between the air passage (11) and the test chamber (2). Specifically, the test facility (1) has a partition part (5) that partitions the air passage (11) and the test chamber (2), and the air outlet (12) and the suction port (13) of the air passage (11). ) Is open to the test chamber (2).

<Configuration of air conditioner>
The air conditioner (10) is configured to adjust the temperature and humidity of the air. As shown in FIG. 1, the air conditioner (10) includes an air passage (11) and an air treatment unit (20) disposed in the air passage (11). Further, the air conditioner (10) includes a heat source unit (not shown) for supplying a cooling medium or a heating medium to the air processing unit (20), and a heat medium circuit that connects the air processing unit (20) and the heat source unit. (40) (only a part is shown).

<Air treatment unit>
The air treatment unit (20) includes a cooling coil unit (21), a fan (25), a heating coil (26) for heating, and a spray unit (35) in order from the upstream side to the downstream side of the air passage (11). And a humidifying heating coil (30) and an eliminator (27).

    The cooling coil unit (21) is composed of a heat exchanger through which a heat medium flows. More specifically, the cooling coil unit (21) is composed of, for example, a fin-and-tube heat exchanger. The cooling coil unit (21) exchanges heat between the heat medium flowing through the cooling coil unit (21) and the air flowing through the air passage (11). The cooling coil unit (21) is a counter flow type in which the direction in which the heat medium flows and the air flow substantially oppose each other.

    The cooling coil unit (21) has a first heat transfer section (22) on the upstream side and a second heat transfer section (23) on the downstream side. The width of the second heat transfer section (23) in the air passage direction is larger than the width of the first heat transfer section (22) in the air passage direction. A relatively low temperature cooling medium and a relatively high temperature heating medium are supplied to the first heat transfer section (22) of the present embodiment in a switchable manner.

    The first heat transfer section (22) has a first lower heat transfer area (22a) formed in a lower portion thereof, and the first upper heat transfer area (22b) is formed in the remaining portion other than the first lower heat transfer area (22a). Is formed. Similarly, the second heat transfer section (23) has a second lower heat transfer area (23a) formed in the lower portion thereof, and the second upper heat transfer area is formed in the remaining portion other than the second lower heat transfer area (23a). (23b) is formed.

    The first lower heat transfer region (22a) has a first path (P1) through which the heat medium flows, and the first upper heat transfer region (22b) has a second path (P2) through which the heat medium flows. A third path (P3) through which the heat medium flows is formed in the lower heat transfer area (23a), and a fourth path (P4) through which the heat medium flows is formed in the second upper heat transfer area (23b).

    The first path (P1) and the second path (P2) constitute front row paths (P1, P2) formed on the upstream side of the cooling coil unit (21). The third path (P3) and the fourth path (P4) constitute a rear row path (P3, P4) formed on the downstream side of the front row path (P1, P2) in the cooling coil unit (21).

    The fins of the cooling coil unit (21) of the present embodiment are divided into four fin groups so as to correspond to each path (P1 to P4) one by one. However, the fins of the cooling coil unit (21) may be shared across the heat transfer regions (22a, 22b, 23a, 23b).

    A fan (25) is comprised, for example with a sirocco fan, and conveys the air of an air path (11). The air conveyed by the fan (25) flows alternately through the air passage (11) and the test chamber (2).

    The heating coil (26) for heating is composed of a heat exchanger through which a heating medium flows. The heating heating coil (26) exchanges heat between the heating medium flowing through the heating coil (26) and the air flowing through the air passage (11).

    The spray unit (35) sprays water onto the air flowing through the air passage (11). The spray unit (35) of this embodiment has a plurality (three) of sprays (36). The number of sprays (36) may be one or any other number. Each spray (36) has a nozzle (37) for ejecting water. Each nozzle (37) is supplied with water conveyed by a pump or the like from a water tank. The tip of each nozzle (37) faces the downstream side of the air passage (11) or the humidifying heating coil (30) side.

    In the operation of humidifying the air in the air passage (11) (humidification operation), water is intermittently sprayed from the spray spray (36). Further, the heating medium flows in the humidifying heating coil (30), which will be described later in detail. Air is humidified by applying spray water to the air in the air passage (11). The remaining water that is not contained in the air adheres to the upstream surface of the humidifying heating coil (30). For this reason, when the temperature of air is below freezing point, this water freezes on the surface of the humidifying heating coil (30). In this state, when the spraying operation of the spray spray (36) is stopped, the ice on the surface is melted by the heating medium of the humidifying heating coil (30). As a result, the water after melting is given to the air, and the air is humidified.

    The humidifying heating coil (30) (heating coil) constitutes a heating section capable of releasing heat. The humidifying heating coil (30) of the present embodiment is constituted by, for example, a fin-and-tube heat exchanger through which a heating medium flows. That is, as shown in FIG. 2, the humidifying heating coil (30) includes a plurality of fins (31) arranged in parallel to each other, and a heat transfer tube (32) penetrating the fins (31) in the plate thickness direction. And have. Each fin (31) is formed in a vertically long rectangular shape, and is arranged in the air passage (11) so that its width direction follows the air flow. A plurality of ventilation paths (33) through which air can pass are formed between the fins (31).

    The eliminator (27) constitutes a water droplet scattering prevention member that prevents relatively large water droplets in the air from scattering into the test chamber (2).

<Heat medium circuit>
As shown in FIG. 1, the heat medium circuit (40) is a pipe for supplying a heat medium (a heat medium or a cold medium) generated by the heat source unit to the air treatment unit (20). The heat medium is an antifreeze that does not freeze even at 0 ° C. or lower. The heat medium circuit (40) includes a first circuit (41), a second circuit (61), and a third circuit (64).

    The first circuit (41) corresponds to the cooling coil unit (21). The first circuit (41) includes a first thermal inflow passage (43), a first thermal outflow passage (42), a first cold inflow passage (45), and a first cold outflow passage (44).

    The first heat inflow path (43) constitutes a pipe for supplying the heat medium of the heat source unit to the cooling coil unit (21). A first on-off valve (47) is connected to the first heat inflow passage (43). A pipe for returning the heating medium after flowing through the cooling coil unit (21) to the heat source unit is configured in the first heating outlet (42). A 2nd on-off valve (46) is connected to a 1st warm heat outflow path (42). The first cold heat inflow path (45) constitutes a pipe for supplying the cooling medium of the heat source unit to the cooling coil unit (21). The first cold heat outflow path (44) constitutes a pipe for returning the cold medium after flowing through the cooling coil unit (21) to the heat source unit.

    The first circuit (41) has first to eighth branch pipes (51 to 58). The first branch pipe (51) connects the first thermal outlet channel (42) and one end of the first path (P1). The second branch pipe (52) connects the first thermal outlet channel (42) and one end of the second path (P2). The third branch pipe (53) connects the first heat inflow path (43) and the other end of the first path (P1). The fourth branch pipe (54) connects the first heat inflow path (43) and the other end of the second path (P2). The fifth branch pipe (55) connects the first cold heat inflow path (45) and one end of the third path (P3). The sixth branch pipe (56) connects the first cooling / heating inflow passage (45) and the other end of the fourth path (P4). The seventh branch pipe (57) connects the first cold heat outflow path (44) and the other end of the third path (P3). The eighth branch pipe (58) connects the first cold heat outflow path (44) and the other end of the fourth path (P4).

    The first circuit (41) has a first bypass pipe (59) and a second bypass pipe (60). The first bypass pipe (59) connects the first heat inflow path (43) and the first cold heat inflow path (45). A third on-off valve (48) is connected to the first bypass pipe (59). The 2nd bypass pipe (60) has connected the 1st heat outflow channel (42) and the 1st cold outflow channel (44). A fourth on-off valve (49) is connected to the second bypass pipe (60).

    The first on-off valve (47), the second on-off valve (46), the third on-off valve (48), and the fourth on-off valve (49) are the first circuit (41) (that is, the heat medium circuit (40)). The flow path switching mechanism (46, 47, 48, 49) for switching the heat medium flow path is configured. Specifically, the flow path switching mechanism (46, 47, 48, 49) can be switched at least to the first state, the second state, and the third state.

    In the first state (the state shown in FIG. 2), the first on-off valve (47) and the second on-off valve (46) are closed, and the third on-off valve (48) and the fourth on-off valve (49) are open. It becomes. Thereby, in the cooling coil unit (21), the cooling medium flows through both the front row path (P1, P2) and the rear row path (P3, P4). In the second state (the state shown in FIG. 4), the first on-off valve (47) and the second on-off valve (46) are opened, and the third on-off valve (48) and the fourth on-off valve (49) are closed. It becomes. Thereby, in the cooling coil unit (21), the heating medium flows through the front row path (P1, P2), and the heating medium (including both the heating medium and the cooling medium, the same applies below) flows through the rear row path (P3, P4). Absent. In the third state (the state shown in FIG. 3), the first on-off valve (47), the second on-off valve (46), the third on-off valve (48), and the fourth on-off valve (49) are closed. Thereby, in the cooling coil unit (21), the heat medium does not flow through the front row paths (P1, P2), and the cooling medium flows through the back row paths (P3, P4).

    The flow path switching mechanism is not necessarily limited to the four on-off valves (46, 47, 48, 49), and may be configured by appropriately combining, for example, an on-off valve, a three-way valve, a four-way switching valve, and the like.

    The second circuit (61) corresponds to the heating coil (26) for heating. The second circuit (61) has a second thermal inflow passage (63) and a second thermal outflow passage (62). The outflow end of the second warm heat inflow passage (63) is connected to one end of the path (heat transfer tube) of the heating coil (26) for heating. The inflow end of the second warm heat outflow path (62) is connected to the other end of the path (heat transfer tube) of the heating coil (26) for heating.

    The third circuit (64) corresponds to the humidifying heating coil (30). The third circuit (64) has a third heat inflow passage (66) and a third heat outflow passage (65). The outflow end of the third warm heat inflow path (66) is connected to one end of the path (heat transfer tube) of the humidifying heating coil (30). The inflow end of the third warm heat outflow path (65) is connected to the other end of the path (heat transfer tube) of the humidifying heating coil (30).

   A third bypass pipe (69) and a three-way valve (68) are connected to the third circuit (64). The third bypass pipe (69) connects the third warm heat inflow path (66) and the third warm heat outflow path (65). The three-way valve (68) shuts off the third thermal outlet channel (65) and the third bypass pipe (69), and communicates the third thermal outlet channel (65) with the humidifying heating coil (30). The state is cut into the second state in which the third heat outflow passage (65) and the humidifying heating coil (30) are cut off and the third heat outflow passage (65) and the third bypass pipe (69) communicate with each other. It is configured to be replaced.

    A flow rate adjusting mechanism (not shown) for adjusting the flow rate of the heating medium flowing through the humidifying heating coil (30) is connected to the third circuit (64). Examples of the flow rate adjusting mechanism include a variable flow rate pump connected to the third circuit (64) and a flow rate adjusting valve. Note that, as described above, the three-way valve (68) has a state in which the heating medium flows through the humidifying heating coil (30) (first state) and a state in which the heating medium does not flow through the humidifying heating coil (30) (first 2 state).

<Configuration related to defrosting operation of air-conditioning unit under test>
The above-mentioned tester-side air conditioner (A) can appropriately perform a defrost operation (evaporator-side defrost operation) in order to melt frost on the surface of the outdoor heat exchanger (4). For example, so-called reverse cycle defrost is performed as the evaporator-side defrost operation, for example. That is, in the evaporator side defrost operation, the high-pressure refrigerant compressed by the compressor is sent to the outdoor heat exchanger (4). Thereby, the frost on the surface of the outdoor heat exchanger (4) is melted from the inside. Note that the evaporator-side defrost operation is not necessarily reverse cycle defrost, and may use a heat source such as a heater.

    Further, the start of execution of the evaporator-side defrost operation can be appropriately determined based on, for example, the temperature and pressure of the refrigerant in the outdoor heat exchanger (4), the temperature of the air passing through the outdoor heat exchanger (4), and the like. . The determination of the end of the defrosting operation is appropriately made based on, for example, the execution time of the evaporator side defrosting operation, the temperature and pressure of the refrigerant in the outdoor heat exchanger (4), the temperature of the air passing through the outdoor heat exchanger (4), etc. be able to.

    The device under test side air conditioner (A) of this embodiment includes an output unit (16) that outputs an output signal (defrost signal) when the evaporator side defrost operation is executed. That is, the defrost signal can be said to be a signal indicating that the evaporator-side defrost operation is being performed. This output signal is received by the controller (70) of the air conditioner (10).

<Sensor>
The air conditioner (10) includes a temperature detection unit that detects the temperature of the air in the test chamber (2), and a humidity detection unit that detects the humidity of the air in the test chamber (2). In the air conditioner (10) of the present embodiment, for example, the temperature detection unit and the humidity detection unit are shared by the dew point temperature sensor (15). That is, the dew point temperature sensor (15) is configured to be able to detect the temperature Tr of the test chamber (2) and the dew point temperature Td serving as an index indicating the humidity (relative humidity in this example) of the test chamber (2). .

    In addition, you may comprise a temperature detection part and a humidity detection part with the sensor of a separate member, respectively. In addition, the humidity detection unit may be a system other than the dew point temperature sensor.

<Controller>
The controller (70) includes a control board having a CPU (Central Processing Unit) and a storage unit such as a memory. Sensors such as the temperature Tr detected by the dew point temperature sensor (15) and the dew point temperature Td are input to the controller (70). Based on such detection signals and the like, the controller (70) is configured based on each device of the air conditioner (10) (fan (25), on-off valves (46, 47, 48, 49), spray unit (35) And so on.

    The controller (70) includes a receiving unit (71), a valve control unit (72), and a setting unit (73). The defrost signal output from the unit under test side air conditioner (A) is input to the receiver (71).

    The valve controller (72) controls the flow path switching mechanism (46, 47, 48, 49) according to the defrost signal input to the receiver (71). That is, in principle, the valve control unit (72) is linked to the cooling coil unit (21) in conjunction with the defrosting operation (evaporator side defrosting operation) of the outdoor heat exchanger (4) of the unit under test air conditioning system (A). The flow path switching mechanism (46, 47, 48, 49) is controlled so as to perform the defrosting operation (coil side defrosting operation). More specifically, when the defrost signal is input to the receiving unit (71), the valve control unit (72) sets the flow path switching mechanism (46, 47, 48, 49) to the second state. As a result, the heating medium flows through only the front row path (P1, P2) of the front row path (P1, P2) and the rear row path (P3, P4), and the coil side defrosts the cooling coil unit (21) with the heating medium. A defrost operation (second operation) is performed.

    The valve controller (72) counts the number N of evaporator-side defrost operations, and performs the coil-side defrost operation in conjunction with the evaporator-side defrost operation only when this number reaches a predetermined number Ns (for example, 5 times). Let it run. That is, the controller (70) executes the coil-side defrost operation every time the defrost operation of the outdoor heat exchanger (4) reaches Ns a predetermined number of times. When the coil side defrost operation reaches Ns a plurality of times, the counted number N is reset again.

    When the coil-side defrost operation ends, the valve control unit (72) places the flow path switching mechanism (46, 47, 48, 49) in the third state. Thereby, the heating medium (cooling medium and heating medium) flows through the front row path (P1, P2), the cooling medium flows through the rear row path (P3, P4), and the second cooling operation for cooling the air with the cooling medium ( A third operation) is performed. Details of these operations will be described later.

    The setting unit (73) switches between a first setting that allows the coil-side defrosting operation and a second setting that prohibits the coil-side defrosting operation. That is, when the setting unit (73) is set to the first setting, as described above, the coil-side defrost interlocked with the evaporator-side defrost can be executed. On the other hand, when the setting unit (73) is set to the second setting, even if the evaporator-side defrost is executed (strictly, even if the number N reaches Ns), the coil-side defrost operation is not executed. . Thus, the user or the like can appropriately change whether or not the coil-side defrosting operation can be performed according to the specifications of the air-conditioner under test (A), operating conditions, and the surrounding environment.

-Driving action-
The air conditioner (10) performs pull-down operation, normal operation, and defrost operation (coil side defrost operation).

    The pull-down operation is an operation for reducing the temperature (dry bulb temperature) Tr of the test chamber (2) to a predetermined target temperature Ts at the start of the test.

    The normal operation is an operation in which, after the pull-down operation, the temperature Tr of the test chamber (2) is maintained at the target temperature Ts, and the humidity (dew point temperature Td) of the test chamber (2) is brought close to the target value. Therefore, in normal operation, as a rule, a humidifying operation for humidifying air is performed. Further, the target temperature Ts of the test chamber (2) is set to a predetermined temperature lower than 0 ° C. (that is, below freezing point).

    The coil-side defrost operation is an operation for melting frost adhering to the surface of the cooling coil unit (21). The coil-side defrost operation is executed in conjunction with the defrost operation of the unit under test side air conditioner (A) in the pull-down operation or the normal operation.

<Pull-down operation>
In the pull-down operation shown in FIG. 2, the fan (25) is operated. In the first circuit (41), the flow path switching mechanism (46, 47, 48, 49) is in the first state, and the cooling medium is supplied to both the front row path (P1, P2) and the rear row path (P3, P4). (First operation). The heating medium is not supplied to the second circuit (61) and the third circuit (64). Therefore, in the pull-down operation, the cooling coil unit (21) is operated, and the heating coil (26) for heating and the heating coil (30) for humidification are not operated. In the pull-down operation, the spray unit (35) is also stopped.

    In the cooling coil unit (21) during the pull-down operation, the cooling medium is supplied to the first heat transfer section (22) and the second heat transfer section (23). That is, as shown in FIG. 2, the cooling medium flowing through the first cold inflow passage (45) branches into four paths (P1 to P4) and finally joins in the first cold outflow passage (44). And sent to the heat source unit. Thus, in the pull-down operation, the cooling medium flows through all the paths (P1 to P4) of the cooling coil unit (21). For this reason, the air flowing through the cooling coil unit (21) is cooled by the cooling medium in all the heat transfer regions (22a, 22b, 23a, 23b).

    The air cooled by the cooling coil unit (21) passes through the heating coil (26) for heating, the spray unit (35), the heating coil for humidification (30), and the eliminator (27) as it is, and the test chamber (2 ). By continuing this pull-down operation, the temperature Tr of the test chamber (2) converges to the target temperature Ts lower than 0 ° C.

    For example, when the pull-down operation ends, the heating operation is executed by the device under test side air conditioner (A) that is the device under test. Thereby, in the refrigerant circuit of the air conditioner (A) to be tested, a refrigeration cycle is performed in which the indoor heat exchanger becomes a condenser or a radiator and the outdoor heat exchanger (4) becomes an evaporator. Therefore, the refrigerant flowing through the outdoor heat exchanger (4) absorbs heat from the air in the test chamber (2) and evaporates. Thus, after the pull-down operation, the air in the test chamber (2) is cooled by the outdoor heat exchanger (4).

    The unit under test air conditioner (A) may start the heating operation, for example, at the start of the pull-down operation or in the middle. As a result, the rise time of the air under test apparatus side (A) can be shortened, and the subsequent test time can be shortened.

<Normal operation>
The normal operation is performed when the temperature Tr of the test chamber (2) reaches the target temperature Ts lower than 0 ° C. and the pull-down operation ends.

    In normal operation, the fan (25) is operated. In normal operation, the flow of the heat medium in the cooling coil unit (21) and the heating coil (26) is switched according to the temperature Tr in the test chamber (2).

    Specifically, when the temperature Tr in the test chamber (2) is lower than the target temperature Ts by a predetermined temperature, a heating medium is supplied to the heating coil (26). Further, no heat medium is supplied to the cooling coil unit (21). Thereby, air can be heated by the heating medium of the heating coil (26) for heating, and the temperature Tr of the test chamber (2) can be brought close to the target temperature Ts.

    Further, when the temperature Tr of the test chamber (2) is higher than the target temperature Ts and the temperature difference (Tr−Ts) becomes larger than a predetermined value α, the flow path switching mechanism (46, 47) of the first circuit (41). , 48, 49) is in the third state, and the cooling medium is supplied only to the back row paths (P3, P4) (see FIG. 3). Further, the heating medium is not supplied to the heating coil (26). As a result, in the cooling coil unit (21), the air can be cooled by the back path (P3, P4), and the temperature Tr of the test chamber (2) can be brought close to the target temperature Ts.

    When the temperature Tr in the test chamber (2) is larger than the target temperature Ts and the temperature difference (Tr−Ts) is larger than a predetermined value β (where β is larger than α), the pull-down operation is performed. The flow path switching mechanism (46, 47, 48, 49) of the first circuit (41) is in the first state. As a result, the cooling medium is supplied to the front row paths (P1, P2) and the rear row paths (P3, P4) of the cooling coil unit (21) (see FIG. 2). Further, the heating medium is not supplied to the heating coil (26). Thereby, in the cooling coil unit (21), air can be cooled by the front row path (P1, P2) and the rear row path (P3, P4), and the temperature Tr of the test chamber (2) can be brought close to the target temperature Ts quickly. it can.

    In normal operation, a humidifying operation is performed to bring the dew point temperature Td of the test chamber (2) closer to the target value. However, if the humidifying operation is performed under a condition where the difference between the temperature Tr of the test chamber (2) and the target temperature Ts is larger than a predetermined value, the convergence of the dew point temperature Td is impaired. For this reason, the humidification operation is prohibited under the condition where the difference between the temperature Tr and the target temperature Ts is larger than the predetermined value γ, and the humidification operation is performed when the difference is γ or less.

    In the humidification operation, an operation (spray operation) of spraying water from each spray spray (36) is intermittently executed. At the same time, in the third circuit (64), the three-way valve (68) is in the first state and the thermal medium is supplied to the third thermal inflow passage (66). As a result, the heating medium flows through the humidifying heating coil (30).

    When water is sprayed from the spray (36), a part of this water is applied to the air, and the rest adheres to the humidifying heating coil (30) and freezes. On the other hand, when the spraying operation is stopped, the ice on the surface of the humidifying heating coil (30) absorbs heat from the heating medium and melts. Melted water is applied to the air. As described above, in the humidifying operation, the operation of making the water sprayed from the spray spray (36) into ice on the surface of the humidifying heating coil (30) and the operation of melting the ice with the heating medium are repeated. Thereby, air can be humidified with high humidification efficiency.

<Coil-side defrost operation>
In the unit under test air conditioner (A), frost adheres to the surface of the outdoor heat exchanger (4) by continuing the heating operation. For this reason, the evaporator side defrosting operation is appropriately executed in the unit under test air conditioner (A).

    When the evaporator-side defrosting operation is executed, a defrost signal is output from the output unit (16) of the unit under test air-conditioner (A) each time. This signal is input to the receiver (71) of the air conditioner (10) each time. The valve control unit (72) appropriately counts the number N of signals input to the reception unit (71). When this number N reaches the predetermined value Ns, the valve control section (72) changes the flow path switching mechanism (46, 47, 48, 49) of the first circuit (41) to the third state. Thereby, in the air conditioner (10), the coil-side defrost operation is performed in conjunction with the evaporator-side defrost operation.

    In the coil-side defrost operation shown in FIG. 4, in the first circuit (41), the heating medium flows through the front row paths (P1, P2), and the heating medium does not flow through the rear row paths (P3, P4) (second operation). No heat medium flows through the second circuit (61) and the third circuit (64).

    In the cooling coil unit (21), frost tends to adhere to the surface of the first heat transfer section (22) on the upstream side. This is because in the cooling coil unit (21), the air humidity tends to be lower on the upstream side than on the downstream side. Therefore, in the coil-side defrost operation, the frost of the cooling coil unit (21) can be efficiently melted by flowing the heating medium through the front row paths (P1, P2).

    At this time, since the heating medium is not supplied to the rear path (P3, P4), it is possible to suppress excessive release of the heat of the heating medium into the air. Therefore, an increase in the air temperature in the test chamber (2) accompanying the coil side defrosting operation can be suppressed. On the other hand, since the second heat transfer section (23) is not so frosted, the frost formation of the second heat transfer section (23) is a big problem even if the heating medium of the rear path (P3, P4) is not flowed. Never become.

    In addition, by performing the coil side defrost operation in conjunction with the evaporator side defrost operation, the time during which the air temperature in the test chamber (2) becomes high can be shortened. Thereby, it can suppress that the test time of the to-be-tested machine side air conditioner (A) shortens due to the evaporator side defrost operation.

    That is, if the coil side defrost operation and the evaporator side defrost operation are individually controlled, for example, after the evaporator side defrost operation is completed, the coil side defrost operation may be executed. In this case, since the coil-side defrost operation is executed at the timing when the heating operation is performed again in the air under test apparatus side (A), the air temperature in the test chamber (2) rises during the heating operation. Therefore, in the air-conditioning apparatus under test (A), the heating operation cannot be performed under normal operation conditions, and desired test data cannot be obtained. As a result, the test time during which accurate test data can be obtained is shortened.

    On the other hand, in this embodiment, since the coil side defrost operation is executed in conjunction with the evaporator side defrost operation, the timing of the temperature rise of the air resulting from the two defrost operations also coincides. For this reason, it is possible to avoid an increase in the air temperature in the test chamber (2) after resuming the heating operation, and a sufficient test time can be secured.

    The evaporator-side defrost operation of this embodiment is terminated in conjunction with the end of the coil-side defrost operation. That is, when the evaporator-side defrost operation is finished and no defrost signal is input to the receiver (71), the coil-side defrost operation is also finished. The coil-side defrost operation may be terminated when a predetermined time elapses after the coil-side defrost operation is started, for example. Further, when a predetermined condition indicating that the defrosting of the cooling coil unit (21) is completed, the coil-side defrosting operation may be terminated.

    When the coil-side defrosting operation is completed, no cooling medium or heating medium is supplied to the first circuit (41). Therefore, in the cooling coil unit (21), no heat medium flows through the front row path (P1, P2) and the rear row path (P3, P4) (pause operation).

    After the pause operation, the air conditioner (10) performs a preliminary cooling operation. In the preliminary example cooling operation, the flow path switching mechanism (46, 47, 48, 49) of the first circuit (41) is in the third state. Thereby, in the cooling coil unit (21), as shown in FIG. 3, the heat medium does not flow through the front row paths (P1, P2), and the heat medium flows through the rear row paths (P3, P4).

    In the preliminary cooling operation, the air is cooled by the second heat transfer section (23) of the cooling coil unit (21). As a result, the air in the test chamber (2) quickly decreases. After the coil-side defrosting operation, if the cooling medium flows through both the front row path (P1, P2) and the rear row path (P3, P4), the heating medium flows in the front row path (P1, P2). A cold medium is immediately supplied. For this reason, in the front row path (P1, P2), due to a rapid temperature change of the heat medium, a temperature shock acts on the heat transfer tube, which may cause problems such as breakage of the heat transfer tube. On the other hand, in the preliminary cooling operation of the present embodiment, since the cooling medium is not passed through the front row path (P1, P2), it is possible to suppress the temperature shock from acting on the heat transfer tubes of the front row path (P1, P2).

    When the preliminary cooling operation is executed and a predetermined time elapses, the above-described normal operation is resumed.

    The coil-side defrost operation linked to the evaporator-side defrost operation is executed when the setting unit (73) is in the first setting. On the other hand, when the setting unit (73) is in the second setting, the coil side defrost operation is not executed in conjunction with the evaporator side defrost operation. That is, when the setting unit (73) is set to the second setting, the execution of the coil side defrost operation itself can be prohibited. Thereby, the raise of the air temperature of the test chamber (2) resulting from coil side defrost operation | movement can be suppressed reliably.

-Effect of the embodiment-
In the above embodiment, since the coil-side defrost operation is performed in conjunction with the evaporator-side defrost operation, air is generated due to defrosting of the cooling coil unit (21) during the period when the evaporator-side defrost operation is not performed. An increase in temperature can be avoided. Thereby, the time which can maintain the circumference | surroundings of the outdoor heat exchanger (4) which is an evaporator in desired temperature atmosphere becomes long, and can extend the substantial test time of a to-be-tested machine side air conditioner (A) by extension.

    Moreover, in the said embodiment, since the coil side defrost operation is performed every time the evaporator side defrost operation reaches Ns a plurality of times, the execution frequency of the coil side defrost operation can be reduced. As a result, the increase in the air temperature in the test chamber (2) due to the coil-side defrosting operation can be further suppressed, and the substantial test time of the unit-under-test air conditioner (A) can be further prolonged.

    In the above embodiment, in the coil-side defrost operation for defrosting the cooling coil unit (21), since the heating medium flows only in the front row path (P1, P2), excessive heat radiation from the heating medium to the air is suppressed. And the frost adhering to the 1st heat-transfer part (22) of a cooling coil unit (21) can be removed reliably. As a result, it is possible to prevent the temperature of the test chamber (2) from significantly increasing due to the coil-side defrost operation.

    In the above embodiment, in the coil-side defrost operation, after the defrosting is performed by flowing the heating medium in the front row path (P1, P2), the cooling medium is not immediately flown in the front row path (P1, P2), and the rear row path (P3 , P4) only the pre-cooling operation is performed to flow the cooling medium. For this reason, cooling of air can be restarted rapidly, suppressing the temperature shock of the heat exchanger tube corresponding to the front row path (P1, P2).

<< Modification of Embodiment >>
When the controller (70) of the above-described embodiment receives the defrost signal output from the unit under test air conditioner (A), the controller performs the evaporator-side defrost operation. However, the controller (70) may execute an evaporator-side defrost operation when other conditions are satisfied. This modification will be described in detail.

<Modification 1>
In the modification 1 shown in FIG. 5, the anemometer (17) which is a wind speed sensor is provided in the vicinity of the outdoor fan (6) of the to-be-tested machine side air conditioner (A). An anemometer (17) detects the wind speed of the air which an outdoor fan (6) conveys. On the other hand, the detection signal of the anemometer (17) is input to the controller (70) of the air conditioner (10).

    When the unit under test air conditioner (A) performs the heating operation, the outdoor fan (6) becomes an evaporator fan. When the EUT-side air conditioner (A) performs the evaporator-side defrost operation, the outdoor fan (6) is stopped and the above-described reverse cycle defrost is performed. For this reason, when the evaporator side defrost operation is executed, the wind speed detected by the anemometer (17) becomes substantially zero. Therefore, the controller (70) determines that the evaporator-side defrosting operation has been performed when the wind speed detected by the anemometer (17) becomes a predetermined value or less (eg, zero). And a controller (70) performs the coil side defrost operation | movement mentioned above in accordance with this timing. Thereby, also in the modification 1, the coil side defrost operation can be executed in conjunction with the evaporator side defrost operation.

<Modification 2>
When the device under test side air conditioner (A) shifts from the heating operation to the evaporator side defrost operation, the compressor of the refrigerant circuit temporarily stops. Therefore, for example, it is possible to determine the evaporator-side defrost operation on condition that the input current (that is, power consumption) of the air-conditioner (A) to be tested is lower than a predetermined value. In this case, the controller (70) receives a signal corresponding to the input current of the unit under test air conditioner (A), and executes the coil-side defrost operation when the input current is equal to or less than a predetermined value.

<< Other Embodiments >>
The controller (70) of the cooling device (10) of the above-described embodiment causes the coil-side defrost operation to be executed each time the evaporator-side defrost operation execution count N reaches a predetermined multiple Ns. However, the controller (70) may execute the coil-side defrost operation every time the evaporator-side defrost operation is executed. That is, Ns = 1 may be set.

    The refrigeration apparatus (A) that is the device under test does not necessarily have to be an air conditioner, and may have another configuration as long as it performs a refrigeration cycle. Specifically, an evaporator such as a cooler, a chiller unit, or a water heater for cooling a refrigerator or a freezer may be used as a device under test.

    As described above, the present invention is useful for an air conditioner.

2 Test room 4 Outdoor heat exchanger (evaporator)
10 Air conditioner 17 Anemometer (wind speed sensor)
21 Cooling coil unit (cooling coil)
25 Outdoor fan (evaporator fan)
70 Controller 73 Setting Part A Air Unit for Test Equipment (Refrigeration Equipment)

Claims (5)

An air conditioner for a test chamber (2) in which an evaporator (4) of a refrigeration apparatus (A) that is a device under test is disposed,
A cooling coil (21) for cooling the air by means of a cooling medium;
A controller (70) for executing the defrosting operation on the coil side for defrosting the cooling coil (21) in conjunction with the defrosting operation on the evaporator side for defrosting the evaporator (4) by the refrigeration apparatus (A). ) And an air conditioner. In claim 1,
The air conditioner characterized in that the controller (70) causes the coil-side defrost operation to be executed each time the evaporator-side defrost operation reaches a predetermined number of times. In claim 1 or 2,
A first setting for executing the defrosting operation on the coil side in conjunction with the defrosting operation on the evaporator side, and a second setting for prohibiting execution of the defrosting operation on the coil side in conjunction with the defrosting operation on the evaporator side An air conditioner comprising a setting unit (73) capable of switching between settings. In any one of Claims 1 thru | or 3,
When the controller (70) receives an output signal output from the refrigeration apparatus (A) in conjunction with the evaporator-side defrost operation, the controller (70) executes the coil-side defrost operation. Harmony device. In any one of Claims 1 thru | or 3,
The refrigeration apparatus (A) includes an evaporator fan (25) that is stopped when a defrost operation on the evaporator side is executed,
A wind speed sensor (17) for detecting the wind speed of the evaporator fan (25),
The air conditioner characterized in that the controller (70) executes a defrosting operation on the coil side when the wind speed detected by the wind speed sensor (17) becomes a predetermined value or less.

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