JP2011163585A - Thermo-hygrostat - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermo-hygrostat capable of saving energy by executing a defrosting operation without degrading testing accuracy of environment testing. <P>SOLUTION: This thermo-hygrostat 1 includes an article setup chamber 3 and an air conditioning passage 5, and a heat exchanger 6 for cooling/dehumidification, constituting a part of a refrigerating machine is disposed inside of the air conditioning passage 5. In a cooling device 20, a compressor 23, a condenser 24, an expanding means 25 and the heat exchanger 6 for cooling/dehumidification are connected by refrigerant circulation piping 26 to configure a circular refrigerant circulation circuit 22, and a phase-change refrigerant is sealed therein. The heat exchanger 6 for cooling/dehumidification is provided with a sub-flow channel 29 as a part of the refrigerant circulation piping 26 functioned as heating piping, near its lower part, and the defrosting operation is executed by the heat of high-temperature refrigerant flowing to the sub-flow channel 29. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a constant temperature and humidity device that can be adjusted to a target temperature and humidity within a predetermined warehouse or room, and more particularly to a constant temperature and humidity device used as an environmental test device.

Environmental testing is known as a measure for testing the durability of equipment and components.
By the way, as an apparatus for testing durability against changes in temperature and humidity among environmental tests, there is an apparatus called a constant temperature and humidity apparatus. This type of constant temperature and humidity device includes a heater, a cooling device, and a humidification device, and presets target values of temperature and humidity in the cabinet to create a desired environment.

  Here, the cooling device employed in the constant temperature and humidity device has a configuration in which a compressor, a condenser, an expansion means, and an evaporator (heat exchanger) are connected by piping to form a circulation circuit, and the circulation circuit A refrigerant that changes phase is enclosed therein and a refrigeration cycle is executed. That is, in the cooling device, the refrigerant is vaporized at a low temperature by the evaporator, and the temperature is lowered by the heat of vaporization. Therefore, this evaporator is installed in the cabinet or in an external air conditioner unit to cool the air in the cabinet. can do.

By the way, when performing an environmental test in which the interior is kept at a low temperature and high humidity for a long period of time, as shown in FIG. 10, the refrigerant pipes constituting the evaporator arranged in the warehouse and the fins attached to the refrigerant pipes In other words, a large amount of water vapor in the air frosted, resulting in a problem of reducing the thermal efficiency of the evaporator. In addition, the dot area | region on drawing represents frost.
Therefore, in Patent Document 1, a bypass flow path is provided in a circulation circuit in which a refrigeration cycle is executed, and a high-temperature refrigerant compressed by a compressor is flowed to an evaporator via a bypass flow path as needed, and directly A refrigeration cycle apparatus having a function of dissolving and defrosting frost (direct hot gas defrost, hereinafter also referred to as direct defrost) is disclosed.

JP 2009-19779 A

  However, when defrosting is performed directly as a defrosting operation, the frost melts from the side that is attached to the evaporator (the side that is not exposed to air). It drops downward so that the fixing force is weakened and peeled off from the evaporator. In particular, since the frost at the bottom of the evaporator grows greatly downward, it is easier to peel off from the evaporator than the frost of other parts, and falls downward in a large lump state as shown in FIG. As a result, there was a concern that some of the fallen frost or melted water would scatter to the position where the sample was installed.

  Moreover, if direct defrost is employed as the defrosting operation, the cooling action in the evaporator must be temporarily stopped, which is not preferable for an environmental test that needs to maintain a certain condition for a certain period. For this reason, when direct defrost is executed every time the defrosting operation is performed, the test environment is temporarily collapsed each time, and there is a problem that the test accuracy is lowered.

  As another defrosting means, there is a measure to provide a heater near the evaporator to melt the frost indirectly. According to this means, frost can be gradually melted from the surface side, so the above-mentioned problems can be solved. However, in an environmental test performed over a long period of time, power consumption becomes large and it is difficult to save energy. I want to avoid it. In addition, there are dissatisfactions such as high manufacturing costs and a large installation space requiring a large installation space.

  Therefore, the conventional technology performs defrosting operation without reducing the test accuracy in the environmental test that needs to reduce the manufacturing cost or maintain the low temperature and high humidity environment for a long period of time. It was difficult to plan.

  Therefore, in the present invention, in view of the above-described problems of the prior art, it is an object to provide a constant temperature and humidity device that can perform a defrosting operation and save energy without reducing test accuracy of an environmental test. To do.

  The invention according to claim 1 for solving the above-described problem has an article arrangement chamber and an air conditioning passage that forms a circulation air flow path with respect to the article arrangement chamber, and at least inside the air conditioning passage. In the constant temperature and humidity apparatus provided with a cooling heat exchanger, the cooling heat exchanger is a part of a refrigerator constituting a refrigeration cycle, and the refrigerator includes a compressor, a condenser, and an expansion And the cooling heat exchanger are connected by a refrigerant circulation pipe to form an annular circulation circuit, and the phase change refrigerant is enclosed in the circulation circuit, and the cooling heat exchanger This is a constant temperature and humidity device characterized in that a part of a refrigerant circulation pipe that functions as a heating pipe through which a high-temperature refrigerant compressed by a compressor passes is disposed in the vicinity of the lower part.

The constant temperature and humidity device of the present invention includes a refrigerator that constitutes a refrigeration cycle, and cools the article placement chamber by disposing at least a cooling heat exchanger that is a part of the refrigerator. .
Here, the refrigeration cycle is a thermodynamic cycle that changes the phase of the refrigerant sealed in the circulation circuit and uses the change in thermal energy at that time. Specifically, the refrigerant is compressed in a gaseous state. Then, after a high temperature and a high pressure, the liquid is cooled to a high pressure liquid, and the volume of the liquid high pressure refrigerant is expanded to a low pressure, and then the gas is vaporized and compressed again.
That is, in the constant temperature and humidity device of the present invention, when the refrigerant is vaporized in the cooling heat exchanger, the article arrangement chamber is cooled by exchanging heat with the air passing through the cooling heat exchanger in the air conditioning passage. Thus, a low temperature environment can be provided. However, as described above, when performing an environmental test such as low temperature and high humidity over a long period of time, water vapor in the air is applied to the refrigerant pipes constituting the cooling heat exchanger, fins attached to the refrigerant pipes, and the like. However, there was a problem of frost formation.

  Therefore, in the constant temperature and humidity device of the present invention, a part of the refrigerant circulation pipe functioning as a heating pipe is arranged near the lower part of the cooling heat exchanger. In other words, for example, a part of the refrigerant circulation pipe can be detoured so that the high-temperature refrigerant discharged from the compressor flows near the lower portion of the cooling heat exchanger. As a result, the frost frosted mainly on the lower part of the cooling heat exchanger can be indirectly melted by the heat of the high-temperature refrigerant (indirect hot gas type defrost, hereinafter also referred to as indirect defrost). At this time, the frost that has formed on the lower part of the cooling heat exchanger gradually melts from the surface side (side exposed to air), so even if a frost block is formed, it falls downward in the block state. Is prevented. As a result, the problem that a part of frost or water is scattered to the article arrangement room side is solved.

Furthermore, in the constant temperature and humidity device of the present invention, since the high-temperature refrigerant flows through the heating pipe during the defrosting operation, the original function of the cooling heat exchanger is not stopped. That is, even in an environmental test that maintains a low temperature for a long period of time, for example, by flowing a high-temperature refrigerant through the heating pipe before frosting, frost growth can be minimized. It is not necessary to perform a defrosting operation (direct defrost) enough to stop the cooling heat exchanger as described above, or the frost can be melted by a short time direct defrost, and as a result A decrease in test accuracy is prevented.
Therefore, according to the constant temperature and humidity device of the present invention, even in a test that is performed while maintaining a low temperature and high humidity environment for a long period of time, the test accuracy is not substantially lowered by the defrosting operation. Furthermore, since the defrosting operation employed in the present invention consumes little electric power as compared with the case where a heater is employed, energy saving can be expected.

By the way, conventionally, there is a constant temperature and humidity device provided with a humidifier.
Humidifiers employed in such a constant temperature and humidity device include a type that radiates water in a mist form and a type that evaporates water stored in a dish. In particular, in a constant temperature and humidity device that employs a humidifier of the type that evaporates the water in the dish and places the humidifier below the cooling heat exchanger, Etc. had a problem of scattering over a wide area.
Accordingly, an invention according to claim 2 for solving the above-described problem has an article arrangement chamber and an air conditioning passage that forms a circulation air flow path with respect to the article arrangement chamber, and the inside of the air conditioning passage. In the constant temperature and humidity device in which at least a humidifier and a heat exchanger for cooling are arranged, the humidifier has a water reservoir portion in which humidifying water is stored, and the heat exchanger for cooling is a refrigeration cycle. The refrigerating machine includes a compressor, a condenser, an expansion means, and a cooling heat exchanger, each of which is connected by a refrigerant circulation pipe to form an annular circulation circuit. The cooling heat exchanger is arranged at least vertically above the water reservoir, and a compressor is provided near the lower portion of the cooling heat exchanger. Refrigerant circulation in which compressed high-temperature refrigerant passes and functions as a heating pipe It is a constant temperature and humidity apparatus, characterized in that part of the pipe is arranged.

The constant temperature and humidity device of the present invention has a configuration in which a cooling heat exchanger is arranged vertically above the water reservoir of the humidifying device, and a refrigerant that functions as a heating pipe in the vicinity of the lower portion of the cooling heat exchanger. A part of the circulation piping is arranged.
That is, even if the cooling heat exchanger directly receives the steam generated by the humidifier and is in an environment where frost is likely to be generated, the heating pipe arranged near the lower part of the cooling heat exchanger Frosted frost can be gradually melted from the surface side. Thus, similarly to the above, the frost that has formed on the lowermost part of the cooling heat exchanger is prevented from falling downward during the defrosting, so the water in the water reservoir is scattered on the article placement chamber side or the like. There is nothing. Furthermore, even in an environmental test that maintains a low temperature for a long period of time, for example, by flowing a high-temperature refrigerant through a heating pipe before frosting, frost growth can be minimized. The defrosting operation for stopping the cooling heat exchanger as described above is not necessary, and consequently the test accuracy is prevented from being lowered.

  According to a third aspect of the present invention, the refrigerant circulation pipe includes a main flow path for flowing the refrigerant from the compressor to the condenser, and a sub flow path connected in parallel to the main flow path, and the middle of the sub flow path. The constant temperature and humidity device according to claim 1, wherein the portion functions as a heating pipe.

  According to this configuration, the refrigerant circulation pipe has the main flow path for flowing the refrigerant from the compressor to the condenser and the sub flow path connected in parallel to the main flow path, and the intermediate portion of the sub flow path is the heat exchange for cooling. Since it is arranged near the lower part of the vessel, for example, by providing an open / close valve (such as an electromagnetic valve) in the sub-channel, a high-temperature refrigerant can flow in the sub-channel as required. In other words, when performing an environmental test or the like that does not frost, a heater is used because it can be used as a heater for heating the article placement chamber by allowing the refrigerant to flow only in the sub-flow path. More energy saving. That is, according to the constant temperature and humidity device of the present invention, the sub-flow path can function as a heating pipe (for defrosting) or a heater (for indoor heating) regardless of whether or not frosting occurs. High energy saving effect.

  The invention according to claim 4 can interrupt the passage of the refrigerant to the heating pipe, and when the inside of the air conditioning passage becomes an environment where the cooling heat exchanger is frosted, the heating pipe is provided. The constant temperature and humidity device according to claim 3, wherein the refrigerant is allowed to pass through.

  According to such a configuration, the constant temperature and humidity device can intermittently pass the refrigerant through the heating pipe, and therefore can be rationally controlled. That is, the constant temperature and humidity device of the present invention is frosted on the cooling heat exchanger in order to pass the high-temperature refrigerant through the heating pipe on the condition that the cooling heat exchanger is in a frosting environment. The frost can be melted in a timely manner. Therefore, since the constant temperature and humidity apparatus of the present invention can be melted before frost grows greatly, it is a preferable configuration from the viewpoints of thermal efficiency and environmental tests.

  According to the fifth aspect of the present invention, it is possible to intermittently pass the refrigerant through the heating pipe, and the inside of the air conditioning passage becomes an environment where the cooling heat exchanger is frosted, and the environment continues for a certain period of time. The constant temperature and humidity device according to claim 3, wherein the refrigerant is passed through the heating pipe.

  According to such a configuration, the constant temperature and humidity device can intermittently pass the refrigerant through the heating pipe, and therefore can be rationally controlled. In other words, the constant temperature and humidity device becomes an environment where the cooling heat exchanger is frosted, and the high temperature refrigerant passes through the heating pipe on the condition that the environment has continued for a certain period of time. Frosted frost can be melted without making it larger than a certain level. Therefore, since the constant temperature and humidity apparatus of the present invention can be melted before frost grows larger than a certain level, it is a preferable configuration from the viewpoint of thermal efficiency and environmental testing.

  According to the sixth aspect of the present invention, it is possible to interrupt the passage of the refrigerant to the heating pipe, and it is expected that the inside of the air conditioning passage will be an environment where the cooling heat exchanger is frosted by a predetermined condition. In this case, the constant temperature and humidity device according to claim 3, wherein the refrigerant is passed through the heating pipe.

  According to such a configuration, the constant temperature and humidity device can intermittently pass the refrigerant through the heating pipe, and therefore can be rationally controlled. That is, the constant temperature and humidity device allows a high-temperature refrigerant to pass through the heating pipe when a predetermined condition is expected to cause the cooling heat exchanger to form a frost. Frosting frost can be efficiently melted. Therefore, in the constant temperature and humidity device of the present invention, the defrosting operation is performed immediately before frost is actually generated, and it can be melted before the frost grows. Therefore, from the viewpoint of thermal efficiency and environmental testing. Is a more preferable configuration.

Here, the water vapor in the air is liquefied on the surface when the temperature of the cooling heat exchanger falls below the dew point temperature, and becomes ice or frost when the temperature of the cooling heat exchanger falls below zero degrees Celsius. . That is, it is considered to be efficient to control the defrosting operation based on the condition that the dew point temperature is not more than 0 degrees Celsius or less.
Therefore, in the invention according to claim 7, the temperature at which the refrigerant in the cooling heat exchanger vaporizes is equal to or lower than the dew point temperature of the air passing through the air conditioning passage, and the refrigerant in the cooling heat exchanger vaporizes. The constant temperature and humidity according to any one of claims 4 to 6, characterized in that when the conditions at which the temperature is equal to or less than zero degrees Celsius are met, the cooling heat exchanger is regarded as an environment that forms frost. Device.

  According to such a configuration, on the condition that the temperature at which frost is formed is obtained, it is considered that the cooling heat exchanger is frosted, so that the frost forming on the cooling heat exchanger is efficiently melted. Can do.

  In the constant temperature and humidity device of the present invention, a part of the refrigerant circulation pipe constituting the refrigerator is arranged in the vicinity of the lower part of the cooling heat exchanger to allow the high-temperature refrigerant to pass therethrough. Frosted frost can be gradually melted from the surface side. Thereby, it is possible to prevent the frost in a lump state from falling, or it is not necessary to perform a defrosting operation to stop the function of the cooling heat exchanger for a certain period of time, so the test accuracy of the environmental test is lowered. Nothing will happen. Furthermore, even if the defrosting operation is performed for a long period of time, power is hardly consumed as compared with the case where a heater is employed, so that energy saving can be achieved.

It is a conceptual diagram which shows the constant temperature and humidity apparatus which concerns on embodiment of this invention. It is a conceptual diagram which shows the relationship between the heat exchanger for cooling dehumidification and heating piping in the A section of FIG. It is a block diagram which shows the control apparatus of the constant temperature and humidity apparatus which concerns on this embodiment. It is a time chart which shows the timing which performs the defrost operation of the constant temperature and humidity apparatus which concerns on this embodiment. It is a conceptual diagram which shows the condition which melt | dissolves the frost which formed in the heat exchanger for cooling dehumidification. It is typical sectional drawing of the AA direction of FIG. 2, (a) is the conventional constant temperature and humidity apparatus, (b) is the constant temperature and humidity apparatus which concerns on embodiment of this invention. It is a conceptual diagram which shows the constant temperature and humidity apparatus which concerns on another embodiment of this invention. It is a conceptual diagram which shows the constant temperature and humidity apparatus which concerns on another embodiment of this invention. It is a conceptual diagram which shows the modification of the heat exchanger for cooling dehumidification. It is a conceptual diagram which shows the state which frosted to the heat exchanger for cooling dehumidification. It is a conceptual diagram which shows the defrost state at the time of performing a direct hot gas type defrost.

  Hereinafter, embodiments of the present invention will be described.

As shown in FIG. 1, the constant temperature and humidity device 1 includes a constant temperature and humidity chamber 2 surrounded by a heat insulating material 15. The interior of the constant temperature and humidity chamber 2 is divided into an article placement chamber 3 and an air conditioning passage 5 by a partition plate 16, and an opening through which the article placement chamber 3 and the air conditioning passage 5 communicate with each other on the upper side and the lower side. Is provided.
The article placement chamber 3 includes a room temperature detection sensor 11 that detects the temperature of the room and a humidity detection sensor that detects the relative humidity of the room in a space in which equipment, parts, and the like serving as samples are placed during an environmental test. 12 is provided. The indoor temperature detection sensor 11 is, for example, a known thermocouple.

In the air conditioning passage 5, a humidifier 8, a cooling / dehumidifying heat exchanger (cooling heat exchanger, evaporator) 6, a heater 7, and a fan 10 are arranged in order from the lower side.
The humidifier 8 is a known one and supplies steam.
The cooling and dehumidifying heat exchanger (evaporator) 6 is a part of a cooling device 20 to be described later, and a phase-change refrigerant circulates therein.
The heater 7 is a known electric heater that heats the air passing through the air conditioning passage 5.
The fan 10 is a well-known one and sends out air.

  In the constant temperature and humidity device 1 of the present embodiment, the air in the constant temperature and humidity chamber 2 is circulated by the fan 10, and a desired environment is created in the article placement chamber 3. That is, the air in the constant temperature and humidity chamber 2 is sucked by the fan 10 from the opening on the lower side of the partition plate 16 to the air conditioning passage 5 side, passes through the air conditioning passage 5 vertically upward, and the partition plate 16. From the opening on the upper side of the product to the article placement chamber 3 side.

More specifically, when the fan 10 is started, the air in the air conditioning passage 5 is sucked into the fan 10 and sent out from the opening on the upper side of the partition plate 16. As a result, an air flow is formed along the wall surface in the article placement chamber 3. Then, the air that has reached the opening on the lower side of the partition plate 16 is again introduced into the air conditioning passage 5.
As described above, the air conditioning passage 5 is provided with the humidifier 8 and the cooling / dehumidifying heat exchanger (cooling heat exchanger, evaporator) 6 in order along the air flow direction. The air introduced into the use passage 5 passes through the humidifier 8 and then flows to the cooling / dehumidification heat exchanger 6 side. In other words, in the present embodiment, when the humidifier 8 and the cooling / dehumidifying heat exchanger 6 are operated simultaneously, the air humidified by the humidifier 8 is dehumidified by the cooling / dehumidifying heat exchanger 6. . Then, the air that has passed through the cooling and dehumidifying heat exchanger 6 is heated by the heater 6 on the downstream side of the cooling and dehumidifying heat exchanger 6 in the air flow direction, and is sucked into the fan 10 again from the upper opening. Sent out.

In the constant temperature and humidity device 1, the temperature and humidity in the article placement chamber 3 are monitored by the indoor temperature detection sensor 11 and the humidity detection sensor 12. When the temperature in the article placement chamber 3 is lower than the temperature of the set environment, the flow rate of the refrigerant flowing through the cooling / dehumidification heat exchanger 6 is decreased, the output of the heater 7 is increased, and the article placement chamber 3 is increased. 3 is higher than the temperature of the set environment, the flow rate of the refrigerant flowing through the cooling / dehumidifying heat exchanger 6 is increased, or the output of the heater 7 is decreased to control the set temperature. .
When the humidity in the article placement chamber 3 is lower than the humidity of the set environment, steam is generated from the humidifier 8 and mixed with the air passing through the air conditioning passage 5.

  Next, the cooling device 20 employed in the present embodiment will be described.

  The cooling device 20 employed in the present embodiment includes a refrigerant circulation circuit 22 through which a refrigerant that changes phase between gas and liquid flows. The refrigerant circulation circuit 22 executes a series of cycles (refrigeration cycles) for compressing and condensing the phase-change refrigerant, evaporating the refrigerant, and cooling the compressor 23, a condenser (heat exchanger) 24, The refrigerating machine includes an expansion valve (expansion means) 25, a heat exchanger (evaporator) 6 for cooling and dehumidification, and a refrigerant circulation pipe 26 that connects these devices in an annular shape.

  Here, the cooling / dehumidifying heat exchanger 6 employed in the constant temperature and humidity device 1 of the present embodiment will be described in detail. As shown in FIG. The heat exchanger includes a refrigerant pipe (refrigerant flow path portion) 31 and fins (heat radiating plates) 32 provided around the refrigerant pipe 31.

The refrigerant pipe 31 is formed by a pipe connected to a single pipe, and has a meandering shape by being folded back multiple times in the middle. More specifically, the refrigerant pipe 31 is configured to expand three-dimensionally in the vertical direction (FIG. 2) and the depth direction of FIG. 2, and a refrigerant inlet 31a is arranged on the upper side of FIG. A refrigerant discharge port 31b is arranged on the lower side.
The fins 32 are thin plates that extend in the vertical direction and the depth direction (FIG. 2), and are arranged so as to be substantially orthogonal to a portion of the refrigerant pipe 31 that extends in the horizontal direction (left-right direction in FIG. 2). And by using the several fin 32, since adjacent piping which comprises the refrigerant | coolant piping 31 can be fixed to an up-down direction and a depth direction at fixed intervals, heat exchange can be performed efficiently. In addition, the end part side of the fin 32 is provided with the overhang | projection part 34 which protruded from the refrigerant | coolant piping 31. FIG.

Therefore, when the compressor 23 of the refrigerant circulation circuit 22 is started, the gas-phase refrigerant is compressed, cooled by the condenser, and made into a high-pressure liquid. Then, the liquid refrigerant enters the heat exchanger 6 for cooling and dehumidification through the expansion valve 25 and is vaporized in a low pressure state. And the heat exchanger 6 for cooling and dehumidification is made into low temperature with a refrigerant | coolant, and the air which passes the channel | path 5 for an air conditioning can be cooled. In the constant temperature and humidity device 1 of the present embodiment, the refrigerant temperature detection sensor 28 is provided on the refrigerant introduction side in the cooling and dehumidification heat exchanger 6 so that the temperature detected by the refrigerant temperature detection sensor 28 becomes a predetermined temperature. In addition, the refrigerator is controlled.
Specifically, in the constant temperature and humidity device 1 of the present embodiment, the refrigerator is always turned on while the device 1 is in operation, and precise temperature control is performed by the heater 7. .

  Moreover, in the constant temperature and humidity apparatus 1 of this embodiment, as shown in FIG. 1, two branch paths are provided between the compressor 23 and the condenser 24 in the refrigerant circuit 22, as shown in FIG. An intermediate portion of the branch path is arranged near the lower portion of the cooling and dehumidifying heat exchanger 6, and the other branch path is connected to the cooling and dehumidifying heat exchanger 6. Specifically, the refrigerant circulation pipe 26 between the compressor 23 and the condenser 24 includes a main flow path 27 through which the refrigerant always flows during cooling, and a sub flow path (for heating) connected in parallel to the main flow path 27. 29) and a bypass flow path 39 that is a shortcut from the main flow path 27 to the cooling and dehumidifying heat exchanger 6, and an intermediate portion of the sub-flow path 29 is the lowermost refrigerant pipe 31 of the cooling and dehumidifying heat exchanger 6. It is arranged in parallel with the part extending in the horizontal direction. Further, as shown in FIG. 2, the sub-channel 29 is disposed so as to abut on the protruding portion 34 of the fin 32 of the cooling and dehumidifying heat exchanger 6.

Accordingly, it is possible to propagate the heat of the refrigerant that has been made high-temperature and high-pressure by the compressor 23 to the cooling and dehumidifying heat exchanger 6 through the air and to propagate using the heat conductivity of the fins 32. It becomes possible. The sub-channel 29 is provided with an electromagnetic valve (open / close valve) 30 that restricts the flow of refrigerant to the sub-channel 29. The electromagnetic valve 30 is a normally closed valve that can be controlled to open by energization.
An electromagnetic valve 40 that restricts the flow of refrigerant to the bypass flow path 39 is also provided in the middle of the bypass flow path 39, and the compressor 23 is connected to the bypass flow path 39 by opening the electromagnetic valve 40. Thus, the high-temperature and high-pressure refrigerant can be passed through the cooling and dehumidifying heat exchanger 6. The solenoid valve 40 is also a normally closed valve as described above.

  Next, the relationship between the control device provided in the constant temperature and humidity device 1 of the present embodiment and other devices will be described.

  The control device 50 employed in the present embodiment is constituted by a microcomputer or the like, and as shown in FIG. 3, the signal of the indoor temperature detection sensor 11, the signal of the humidity detection sensor 12, and the signal of the refrigerant temperature detection sensor 28 are received. Entered. The controller 50 calculates the water vapor pressure from the room temperature input from the room temperature detection sensor 11 and the indoor relative humidity input from the humidity detection sensor 12, and sets the water vapor pressure as the saturated water vapor pressure. The dew point calculation program 50a for calculating (dew point temperature) and the evaporation temperature of the refrigerant input from the refrigerant temperature detection sensor 28 are equal to or lower than the dew point temperature calculated by the dew point calculation program 50a or less than zero degrees Celsius. Or a comparison operation program 50b for comparing whether the temperature satisfies the two conditions is stored.

  Here, as described above, generally, the frost is formed under the condition that the temperature of the heat exchanger 6 for cooling and dehumidification is lower than that of the air conditioning passage 5 (in particular, the downstream side in the air flow direction from the humidifier 8). The dew point temperature is not more than 0 degrees Celsius and the water vapor in the air becomes icy frost (solid) as shown in FIG. That is, in the present embodiment, the specific defrosting operation is controlled based on this condition.

In addition, a setting device 51 is connected to the temperature control device 50. The setting device 51 is a device that inputs the temperature and humidity of the setting environment. Specifically, temperature and humidity can be set based on the elapsed time from the start of operation.
On the other hand, a compressor drive circuit 33, a solenoid valve drive circuit 55, a humidifier drive circuit 56, and a heater drive circuit 57 are connected to the output side of the temperature control device 50.

  Therefore, in the constant temperature and humidity device 1 of the present embodiment, a desired environment can be set by the setting device 51, and the refrigerant circulation circuit is based on the input signals of the indoor temperature detection sensor 11, the humidity detection sensor 12, and the refrigerant temperature detection sensor 28. 22, the humidifier 8, and the heater 7 can be controlled efficiently.

  Furthermore, in the thermo-hygrostat 1 of this embodiment, it is possible to perform a defrosting operation under a certain condition. More specifically, as shown in the time chart of FIG. 4, the temperature of the refrigerant passing through the cooling / dehumidifying heat exchanger 6 is lower than the humidifier 8 in the air conditioning passage 5 in the air flow direction downstream side. If the conditions of the dew point temperature or less and the condition of zero degrees Celsius or less are not satisfied, the electromagnetic valve 30 of the sub flow path 29 maintains the closed state. Then, at the moment when the temperature of the refrigerant passing through the cooling and dehumidifying heat exchanger 6 satisfies the condition that it is equal to or lower than the dew point temperature of the air downstream of the humidifier 8 in the air flow direction and equal to or less than zero degrees Celsius, the sub-channel 29 The electromagnetic valve 30 is opened, and the defrosting operation by the heating pipe (sub-channel) 29 is executed.

The defrosting operation is an operation of flowing a high-temperature refrigerant through the sub-channel 29 in order to melt the frost that has started to form frost on the cooling / dehumidifying heat exchanger 6 by continuous operation of the refrigerant circulation circuit 22. The passage 29 functions as a heating pipe. Then, as shown in FIG. 5, the frost in the lower part of the cooling and dehumidifying heat exchanger 6 is melted mainly by the hot air of the refrigerant (indirect defrosting). At this time, since the refrigerant flows also to the main flow path 27, it is not necessary to stop the cooling function of the heat exchanger 6 for cooling and dehumidification. Therefore, according to the constant temperature and humidity apparatus 1 of this embodiment, even if it performs defrost operation, the test precision of an environmental test does not fall.
In addition, since the above-mentioned defrosting operation can melt frost at the initial stage of frost formation, frost does not grow greatly. That is, it is not necessary to execute a direct hot gas type defrost in which a high-temperature refrigerant flows through the bypass passage 39, or even if a direct hot gas type defrost is executed, a very short time operation is sufficient.

  Further, since the sub-channel 29 is disposed in contact with the overhanging portion 34 of the fin 32, the frost in the heat exchanger 6 for cooling and dehumidification is also dissolved from the heat conducted to the fin 32. However, in the present embodiment, even during defrosting, since the low-temperature refrigerant is circulating in the cooling and dehumidifying heat exchanger 6, the frost is not rapidly melted by the heat conducted to the fins 32. That is, the heat conducted to the fins 32 does not cause the frost mass to be peeled off from the cooling / dehumidifying heat exchanger 6 and fall, and can be efficiently defrosted by heat transmitted from a plurality of directions. .

  In addition, the flow of air passing through the cooling and dehumidifying heat exchanger 6 is changed by arranging the sub-channel 29 below the cooling and dehumidifying heat exchanger 6, and the cooling and dehumidifying heat exchanger 6 is frosted. It becomes difficult to do. That is, according to the prior art, as shown in FIG. 6A, the air circulates in a substantially vertical upward direction, but the sub-channel 29 is cooled as in the constant temperature and humidity device 1 of the present embodiment. By disposing it below the dehumidifying heat exchanger 6, the air flow is disturbed near the lower portion of the cooling and dehumidifying heat exchanger 6 as shown in FIG. Furthermore, according to the constant temperature and humidity device 1 of the present embodiment, since a high-temperature refrigerant flows through the sub-flow channel 29, the air flow is more likely to be disturbed by the hot air flow, so that cooling and dehumidification is possible as compared with the prior art. The frosting phenomenon in the lowermost part of the heat exchanger 6 is suppressed.

  Therefore, in the constant temperature and humidity device 1 of the present embodiment, the temperature of the refrigerant passing through the cooling and dehumidifying heat exchanger 6 is equal to or lower than the dew point temperature of the air conditioning passage 5 (especially the downstream side in the air flow direction from the humidifier 8). In the state that does not satisfy the condition of zero degrees Celsius or less, the defrosting operation is not performed, and the defrosting operation peculiar to the present embodiment is performed at the moment when the condition is satisfied. Can be removed. Therefore, the cooling operation is not stopped by flowing a high-temperature refrigerant in the bypass flow path 39, or even if a high-temperature refrigerant is flowed in the bypass flow path 39, only a short time operation is required, so that high test accuracy can be ensured. it can. Further, in the constant temperature and humidity device 1 of the present embodiment, air is more likely to be disturbed near the lower portion of the heat exchanger 6 for cooling and dehumidification by the sub-channel 29, and frosting is difficult compared to the prior art.

Here, an additional description will be given of the action of direct hot gas defrosting. In addition, the arrow shown in FIG. 6 shows the flow of air.
As described above, conventionally, as the defrosting operation of the cooling device, there is an operation (direct defrost) of flowing a high-temperature refrigerant directly to the evaporator using the bypass flow path.
This direct defrost is an operation that melts frost from the side that is in contact with the pipe by opening the solenoid valve 40 and flowing the refrigerant dehumidified at a high temperature and high pressure by the compressor 23 to the cooling and dehumidifying heat exchanger 6. is there. By this operation, the frost is peeled off from the pipe and falls while maintaining a lump state. However, the frost frosted on the upper and middle parts of the cooling and dehumidifying heat exchanger 6 falls while colliding with a pipe adjacent to the lower side of the pipe that was frosted at the time of dropping. When completely leaving the heat exchanger 6, it becomes almost liquid. And in this invention, when the frost which became the substantially liquid state falls, it collides with heating piping and is heated. Thereby, since it falls in the state of a block of frost, the fault which a direct defrost has can be eliminated.

  In the above embodiment, as a condition for performing indirect defrost, whether or not the temperature of the refrigerant is equal to or lower than the dew point temperature of the air conditioning passage 5 and equal to or lower than zero degrees Celsius is monitored, the present invention is limited to this. Alternatively, it may be a condition for performing indirect defrost by monitoring whether the temperature of the refrigerant is equal to or lower than the dew point temperature of the article placement chamber 3 and equal to or lower than zero degrees Celsius.

  In the said embodiment, the structure provided with the control which performs a defrost operation at the moment when the detection temperature of the refrigerant temperature detection sensor 28 satisfied the conditions below the dew point temperature of the air-conditioning channel | path 5 and below zero degree Celsius was shown. However, this invention is not limited to this, You may be the structure provided with the control which performs a defrost operation | movement on condition that the fixed time passed after satisfy | filling the said conditions. According to this control, frost larger than a certain size is not formed.

  In the said embodiment, as shown in FIG. 1, although the structure which employ | adopted the humidifier 8 of the structure which injects mist-like water was shown, this invention is not limited to this, As shown in FIG. The vessel may have a configuration employing a water reservoir 37 in which humidifying water is stored. That is, as described above, since the defrosting operation is executed in the initial stage of frosting by the sub-channel 29, the frost mass does not fall into the water reservoir 37 located below the cooling and dehumidifying heat exchanger 6. . The water reservoir 37 is desirably provided with an electric heater that promotes evaporation of water.

  In the above embodiment, as shown in FIG. 1, the main flow path 27 and the sub flow path 29 are provided, and the configuration in which the refrigerant heated to the high temperature by the compressor 23 is supplied to the sub flow path 29 as necessary. The present invention is not limited to this. For example, as shown in FIG. 8, the refrigerant circulation pipe 26 between the compressor 23 and the condenser 24 may be bypassed to the vicinity of the lower portion of the cooling and dehumidifying heat exchanger 6. Absent.

  In the above embodiment, the configuration in which the defrosting operation is performed when the detection temperature of the refrigerant temperature detection sensor 28 satisfies the condition of the dew point temperature of the air conditioning passage 5 or less and zero degrees Celsius or less is shown. The invention is not limited to this. For example, the defrosting operation is executed from the moment when the temperature of the air conditioning passage 5 falls below zero degrees Celsius, or the moment when the temperature of the air conditioning passage 5 falls below the dew point temperature. You may be the structure provided with control which performs a defrost operation. In short, if the cooling dehumidification heat exchanger 6 is in an environment where frost formation is possible, it is only necessary to execute a control for flowing a high-temperature refrigerant through the sub-channel 29.

  In the above-described embodiment, the configuration including the control of flowing the high-temperature refrigerant through the sub-flow channel 29 only during the defrosting operation is shown, but the present invention is not limited to this, and the article arrangement chamber 3 is heated. Alternatively, a configuration may be adopted in which a high-temperature refrigerant is allowed to flow only through the sub-channel 29. Thereby, energy can be saved even when the room temperature is raised. In this case, it is preferable to provide an electromagnetic valve also on the main flow path 27 side.

  In the above-described embodiment, the configuration in which the sub-channel 29 and the overhanging portion 34 of the fin 32 are in contact with each other is shown. However, the present invention is not limited to this, and the sub-channel 29 and the overhanging portion 34 of the fin 32 are separated. It doesn't matter. Thereby, when not using the function of subchannel 29, the load of a refrigerator can be reduced.

  In the above embodiment, the sub-channel 29 and the main channel 27 are separated from each other. However, the present invention is not limited to this. For example, as shown in FIG. An integrated configuration may be used via the same fin 32. In this case, in consideration of the thermal conductivity of the fins 32, it is desirable to adjust the distance between the sub-channel 29 and the main channel 27 so that the refrigerator is not overloaded.

  Moreover, in the said embodiment, although the structure which has arrange | positioned the heat exchanger for cooling and dehumidification which can perform cooling and dehumidification of air to the air-conditioning channel | path 5 was shown, in this invention, for cooling which can perform only cooling of air A configuration in which a heat exchanger is arranged may be used.

DESCRIPTION OF SYMBOLS 1 Constant temperature and humidity apparatus 2 Constant temperature and humidity tank 3 Article arrangement room 5 Air-conditioning passage 6 Cooling dehumidification heat exchanger (cooling heat exchanger)
20 Cooling device (refrigerator)
22 Refrigerant circulation circuit 23 Compressor 24 Condenser 25 Expansion valve (expansion means)
26 Refrigerant circulation pipe 27 Main flow path 28 Refrigerant temperature detection sensor 29 Sub flow path 32 Fin (radiating plate)

Claims (7)

In the constant temperature and humidity device having an article placement chamber and an air conditioning passage that forms a circulating air flow path for the article placement chamber, and at least a cooling heat exchanger is disposed inside the air conditioning passage,
The cooling heat exchanger is a part of a refrigerator constituting a refrigeration cycle,
In the refrigerator, the compressor, the condenser, the expansion means, and the cooling heat exchanger are connected by a refrigerant circulation pipe to form an annular circulation circuit, and the phase changes in the circulation circuit. It is filled with refrigerant,
A constant temperature and humidity apparatus characterized in that a part of a refrigerant circulation pipe that functions as a heating pipe through which a high-temperature refrigerant compressed by a compressor passes is disposed near the lower portion of the cooling heat exchanger. Constant temperature and humidity having an article arrangement chamber and an air conditioning passage that forms a circulation air flow path for the article arrangement chamber, and at least a humidifier and a cooling heat exchanger are arranged inside the air conditioning passage In the device
The humidifier has a water reservoir in which water for humidification is stored,
The cooling heat exchanger is a part of a refrigerator constituting a refrigeration cycle,
In the refrigerator, the compressor, the condenser, the expansion means, and the cooling heat exchanger are connected by a refrigerant circulation pipe to form an annular circulation circuit, and the phase changes in the circulation circuit. It is filled with refrigerant,
The cooling heat exchanger is disposed at least vertically above the water reservoir,
A constant temperature and humidity apparatus characterized in that a part of a refrigerant circulation pipe that functions as a heating pipe through which a high-temperature refrigerant compressed by a compressor passes is disposed near the lower portion of the cooling heat exchanger. The refrigerant circulation pipe has a main flow path for flowing the refrigerant from the compressor to the condenser, and a sub flow path connected in parallel to the main flow path,
The constant temperature and humidity apparatus according to claim 1 or 2, wherein an intermediate portion of the sub-flow path functions as a heating pipe. It is possible to interrupt the passage of refrigerant to the heating pipe,
The constant temperature and humidity device according to claim 3, wherein the refrigerant is passed through the heating pipe when the inside of the air conditioning passage is in an environment where the cooling heat exchanger is frosted. It is possible to interrupt the passage of refrigerant to the heating pipe,
The constant temperature and humidity device according to claim 3, wherein the inside of the air conditioning passage is in an environment where the cooling heat exchanger is frosted and the refrigerant passes through the heating pipe when the environment continues for a certain period of time. It is possible to interrupt the passage of refrigerant to the heating pipe,
The constant temperature and constant temperature according to claim 3, wherein the refrigerant is allowed to pass through the heating pipe when a predetermined condition predicts that the inside of the air conditioning passage is frosted on the cooling heat exchanger. Wet equipment.   The temperature at which the refrigerant in the cooling heat exchanger evaporates is equal to or lower than the dew point temperature of the air passing through the air conditioning passage, and the temperature at which the refrigerant in the cooling heat exchanger evaporates is equal to or less than zero degrees Celsius. The constant temperature and humidity device according to any one of claims 4 to 6, wherein the device is regarded as an environment in which the cooling heat exchanger is frosted when the following conditions are met.

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