CN111023604B

CN111023604B - Environmental test device and air conditioning device

Info

Publication number: CN111023604B
Application number: CN201910231266.XA
Authority: CN
Inventors: 仓良博伸
Original assignee: Espec Corp
Current assignee: Espec Corp
Priority date: 2018-10-10
Filing date: 2019-03-26
Publication date: 2022-02-18
Anticipated expiration: 2039-03-26
Also published as: CN111023604A; JP2020060324A; JP7054308B2

Abstract

The invention provides an air conditioner capable of reducing temperature in a state of suppressing reduction of humidity or reducing humidity in a state of suppressing reduction of temperature, and provides an environment test device with low power consumption. The air conditioner of the invention has a plurality of heat exchangers, the heat exchanger includes the easy drainage heat exchanger (40) that the condensed water is easy to discharge when generating the condensed water and the difficult drainage heat exchanger (38) that the condensed water is easy to accumulate compared with the easy drainage heat exchanger (40), and can adjust the quantity and/or the cold-storage quantity of the refrigerant supplied to the easy drainage heat exchanger (40) and the difficult drainage heat exchanger (38), the quantity and/or the cold-storage quantity of the refrigerant supplied to the easy drainage heat exchanger (40) is different from the quantity and/or the cold-storage quantity of the refrigerant supplied to the difficult drainage heat exchanger (38).

Description

Environmental test device and air conditioning device

Technical Field

The present invention relates to an environmental test apparatus capable of exposing a test object to a predetermined environment. In addition, the present invention relates to an air conditioning apparatus which is expected to be mounted on an environmental test apparatus and the like.

Background

As a method for investigating the performance and durability of products, parts, and the like, environmental tests are known. The environmental test is carried out using an apparatus called an environmental test apparatus. The environmental test apparatus is, for example, an apparatus for artificially creating a high-temperature environment, a low-temperature environment, a high-humidity environment, or the like.

The environmental test apparatus has a structure shown in fig. 9, for example. The environment testing apparatus 100 shown in fig. 9 includes: a laboratory 3, a cooling unit 106, a heater 6, a humidifying device 7 and a fan 8. The laboratory 3 is a space covered with the heat insulating material 2. The air passage 10 is provided to communicate with the laboratory 3, and the evaporator 107 of the cooling unit 106, the heater 6, the humidifier 7, and the fan 8 are provided in the air passage 10. Further, a temperature sensor 12 and a humidity sensor 13 are provided on the outlet side of the air passage 10.

In the environment testing apparatus 100, the air conditioning apparatus 15 is constituted by the above-described components in the air passage 10, the temperature sensor 12, and the humidity sensor 13.

Here, the heater 6 is a well-known electric heater.

The humidifier 7 is a device combining a humidifying heater 25 and a water tray 26, and heats and evaporates water in the water tray 26 in the humidifying heater 25.

The humidity sensor 13 is not particularly limited as long as it can detect humidity, and for example, a wet-dry bulb hygrometer or the like can be used.

The cooling unit 106 is a unit that realizes a refrigeration cycle using a phase-change heat medium, and includes a circulation circuit 105, and the circulation circuit 105 includes the compressor 101, the condenser 102, and the expansion valve 103 in addition to the evaporator 107.

The cooling unit 106 expands the refrigerant in the evaporator 107, lowers the surface temperature of the evaporator 107, and exchanges heat with the air passing through the air passage 10.

In general, the cooling unit 106 of the environmental test apparatus 100 functions as a temperature lowering unit for lowering the temperature in the test chamber 3 and a humidity lowering unit for lowering the humidity in the test chamber 3.

That is, when the humidity in the test chamber 3 is lowered, the cooling unit 106 is driven to lower the surface temperature of the evaporator 107, thereby condensing the water vapor in the air in contact with the evaporator 107. In the air in contact with the evaporator 107, the vapor pressure of the water contained therein decreases, and the relative humidity decreases.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open No. 2014-66593

Disclosure of Invention

Problems to be solved by the invention

In the environment testing apparatus 100, when the target environment in the test chamber 3 is a low-temperature environment and the temperature in the test chamber 3 approaches the target temperature, the cooling unit 106 and the heater 6 may be used together to maintain the temperature in the test chamber 3 at the target temperature.

Similarly, when the humidity in the test chamber 3 approaches the target humidity, the humidity in the test chamber 3 may be maintained at the target humidity by using the cooling unit 106 and the humidifying device 7.

Here, since the cooling unit 106 has a function as a temperature reducing unit and a function as a humidity reducing unit, there are cases where: for example, when the cooling unit 106 is driven to lower the temperature in the test chamber 3, even if the humidity in the test chamber 3 is not desired to be lowered, the humidity is excessively lowered due to condensation of water vapor on the surface of the evaporator 107.

In addition, there are cases where: when the cooling unit 106 is driven to reduce the humidity in the test room, even when the temperature in the test room 3 is not desired to be reduced, the temperature in the test room 3 is excessively reduced by taking heat from the air on the surface of the evaporator 107.

Therefore, there are cases where the driving amount of the heater 6 and the chance of driving the humidifying device 7 increase.

The present invention has been made in view of the above problems of the prior art, and an object of the present invention is to develop an air conditioning apparatus capable of reducing the temperature while relatively suppressing the reduction in the humidity, or reducing the humidity while relatively suppressing the reduction in the temperature.

Means for solving the problems

An air conditioning apparatus having a cooling function and a dehumidifying function, characterized in that: the heat exchanger includes an easy-drainage heat exchanger in which condensed water is easily drained when condensed water is generated, and a difficult-drainage heat exchanger in which condensed water is more likely to accumulate than in the easy-drainage heat exchanger, and the amount and/or the retained cold heat of the refrigerant supplied to the easy-drainage heat exchanger and the difficult-drainage heat exchanger can be adjusted, and the amount and/or the retained cold heat of the refrigerant supplied to the easy-drainage heat exchanger is different from the amount and/or the retained cold heat of the refrigerant supplied to the difficult-drainage heat exchanger.

The air conditioner of this embodiment includes an easy-to-drain heat exchanger that relatively easily drains condensed water and a difficult-to-drain heat exchanger that relatively easily accumulates condensed water.

Both types of heat exchangers (the easy-to-drain heat exchanger and the difficult-to-drain heat exchanger) function as a cooling dehumidifier having a dehumidification function for reducing the temperature of air, but the sensible heat ratio is different between the easy-to-drain heat exchanger and the difficult-to-drain heat exchanger.

That is, both the easy-to-drain heat exchanger and the difficult-to-drain heat exchanger have a function of reducing the temperature and humidity, but the easy-to-drain heat exchanger has a lower sensible heat ratio and excellent dehumidification performance than the difficult-to-drain heat exchanger. In contrast, the heat exchanger having poor drainability has a higher sensible heat ratio than the heat exchanger having easy drainability, and is more effective in reducing the air temperature.

The reason for this will be explained below.

When the surface temperature of the easy-to-drain heat exchanger is lowered, water vapor condenses on the surface of the easy-to-drain heat exchanger. Therefore, the partial pressure of water vapor in the air decreases, and the humidity decreases. The condensed water generated on the surface of the easy-to-drain heat exchanger is discharged from the easy-to-drain heat exchanger.

If the condensed water discharged from the easy-to-drain heat exchanger is discharged to the outside of the air conditioning system, the amount of moisture in the system is reduced, and the system is dehumidified.

In addition, in the easy-to-drain heat exchanger, since cold and heat are consumed in the condensation of water vapor, the decrease in air temperature (sensible heat) is relatively small.

Therefore, when the easy-to-drain heat exchanger is used, the humidity can be reduced while suppressing the reduction in temperature.

Thus, the easy-to-drain heat exchanger is excellent in dehumidification performance and substantially low in sensible heat ratio.

In contrast, when the surface temperature of the heat exchanger having poor drainability is lowered, although water vapor condenses on the surface, the condensed water remains in the system and is slightly re-evaporated.

That is, the heat exchanger having a low water drainage capacity is likely to accumulate condensed water, and the condensed water is likely to remain on the surface of the heat exchanger having a low water drainage capacity. Therefore, the condensed water generated on the surface of the heat exchanger having a low water repellency remains in the air conditioning system, and the amount of water in the system is relatively reduced. When the condensed water remaining in the heat exchanger having a poor water drainage property is re-evaporated, the partial pressure of water vapor in the air rises and approaches the original humidity.

Therefore, when the heat exchanger difficult to drain is used, the temperature can be lowered while suppressing the decrease in humidity.

Thus, the difficult-to-drain heat exchanger has a substantially high sensible heat ratio.

In the air-conditioning apparatus of this aspect, the amount of the refrigerant supplied to the easy-to-drain heat exchanger having a low sensible heat ratio and the amount of the refrigerant supplied to the difficult-to-drain heat exchanger having a high sensible heat ratio can be adjusted, and the amount of the refrigerant supplied to the easy-to-drain heat exchanger and the amount of the refrigerant supplied to the difficult-to-drain heat exchanger are different from each other.

Therefore, in the air conditioning apparatus of this embodiment, the cooling priority operation and the dehumidification priority operation can be performed.

In the above aspect, it is preferable that the heat exchanger has fins on a surface thereof, and the heat exchanger with low water drainage has a narrower average interval between the fins than the heat exchanger with high water drainage.

The average interval between the fins is narrower in the heat exchanger having poor water drainage than in the heat exchanger having easy water drainage. Therefore, water droplets are likely to accumulate between the fins, and condensed water is likely to accumulate.

On the other hand, in the easy-to-drain heat exchanger, since the average interval between the fins is wider than that in the difficult-to-drain heat exchanger, water droplets easily fall down, and condensed water is hard to accumulate.

In each of the above aspects, it is preferable that the heat exchanger has fins on a surface, the fins of the difficult-to-drain heat exchanger and the easy-to-drain heat exchanger have different surface shapes and different water retaining forces, and the water retaining force of the fins is higher in the difficult-to-drain heat exchanger than in the easy-to-drain heat exchanger.

For example, the water retaining force can be made different by making the surface shape of the fin of the easy-to-drain heat exchanger flat and providing the surface of the fin of the difficult-to-drain heat exchanger with irregularities or the like.

In the above aspects, it is preferable that the heat exchanger has fins on a surface thereof, and the fins of the difficult-to-drain heat exchanger have better wettability with water than the fins of the easy-to-drain heat exchanger.

Wettability is an index indicating affinity between a liquid and a solid, and is expressed in numerical terms by the size of an angle (contact angle) formed between the liquid and a solid surface. The contact angle is large when wettability is poor (low), and is small when wettability is good (high).

The heat exchanger may have a common refrigerant supply source, and the refrigerant may be supplied from the refrigerant supply source to the easy-to-drain heat exchanger and the difficult-to-drain heat exchanger, and the refrigerant supply path may be provided with a flow rate adjusting means.

The heat exchanger may further include a water discharge facilitating side refrigerant supply source for supplying the refrigerant to the water discharge facilitating heat exchanger, and a water discharge difficulty side refrigerant supply source for supplying the refrigerant to the water discharge difficulty heat exchanger.

In the above-described aspects, it is preferable that a target temperature and a target humidity are set, and a current temperature and a current humidity in the predetermined space are adjusted to the target temperature and the target humidity, and when the current temperature is close to the target temperature and the current humidity is higher than the target humidity, an amount of refrigerant supplied to the water-easily drainable heat exchanger and/or a cold-heat retention amount of the refrigerant tend to increase.

According to this aspect, when the humidity is preferentially decreased while the temperature is maintained, a desired effect can be exhibited.

In the above-described aspects, it is preferable that a target temperature and a target humidity be set, a current temperature and a current humidity in the predetermined space be adjusted to the target temperature and the target humidity, and the amount of refrigerant and/or the retained cold heat supplied to the heat exchanger having a poor water drainage property be increased when the current temperature is higher than the target temperature and the current humidity is close to the target humidity.

According to this aspect, when the temperature is lowered with priority in order to maintain the humidity, a desired effect can be exhibited.

In each of the above-described aspects, it is preferable to provide an air blowing unit, wherein the heat exchanger having a low water drainage property is disposed on an upstream side in an air blowing direction, and the heat exchanger having a high water drainage property is disposed on a downstream side in the air blowing direction.

The air blowing unit may blow air to dissipate the condensed water on the surface of the evaporator. Here, when the heat exchanger having a low water drainage ability is provided on the windward side and the heat exchanger having an easy water drainage ability is disposed on the leeward side, even if water droplets accumulated in the heat exchanger having a low water drainage ability are scattered, the water droplets can be captured by the heat exchanger having an easy water drainage ability on the leeward side. Therefore, the water droplets are difficult to enter a laboratory or the like.

In each of the above embodiments, a common refrigerant supply source may be provided, and the refrigerant may be supplied from the refrigerant supply source to the easy-to-drain heat exchanger and the difficult-to-drain heat exchanger, and the heat exchanger may include a bypass passage that bypasses the easy-to-drain heat exchanger or the difficult-to-drain heat exchanger, and a circuit that merges the refrigerant that has passed through one of the easy-to-drain heat exchanger and the difficult-to-drain heat exchanger and the refrigerant that has passed through the bypass passage, and causes the refrigerant to flow to the other heat exchanger.

This embodiment is a cooling circuit recommended when the amount of heat exchange in one heat exchanger is expected to be smaller than the amount of heat exchange in the other heat exchanger.

According to the above-described cooling circuit, the minimum refrigerant flow rate is ensured in both the heat exchangers.

An environment test apparatus having a test room in which a test object is placed and the air conditioner according to any one of the above aspects, characterized in that: the air conditioning apparatus is used to condition the environment in the laboratory.

Effects of the invention

The air conditioner of the present invention has exchangers having different sensible heat ratios, and can reduce the temperature while relatively suppressing the reduction in humidity, or reduce the humidity while relatively suppressing the reduction in temperature.

Drawings

Fig. 1 is a block diagram of an environmental test apparatus according to an embodiment of the present invention.

Fig. 2 is a configuration diagram rewritten for easy viewing of a circuit of the cooling unit of the environment testing apparatus shown in fig. 1.

Fig. 3 is a piping diagram of a cooling unit of the environment testing apparatus shown in fig. 1.

Fig. 4(a) is an explanatory view showing a relationship between the fins of the sensible heat removal evaporator (difficult-to-drain heat exchanger) and the condensed water, and (b) is an explanatory view showing a relationship between the fins of the latent heat removal evaporator (easy-to-drain heat exchanger) and the condensed water.

Fig. 5 is a configuration diagram of a cooling unit of an environment testing apparatus according to another embodiment.

Fig. 6 is a configuration diagram of a cooling unit of an environment testing apparatus according to another embodiment.

Fig. 7(a) to (d) are perspective views showing the shape of the fin of the sensible heat removal evaporator used in another embodiment of the present invention.

Fig. 8 is a perspective view of a sensible heat removal evaporator and a latent heat removal evaporator used in another embodiment of the present invention.

Fig. 9 is a structural diagram of a conventional environmental test apparatus.

Description of the reference numerals

1 environmental test device

3 laboratory

6 Heater

7 humidifying device

8 blower fan

10 air passage

20 air conditioning device

30. 61, 62, 72 cooling unit

38 sensible heat removing evaporator (Heat exchanger difficult to drain)

Evaporator for removing latent heat 40 (heat exchanger easy to drain)

41 Fin

42 fin

52 sensible heat removing side expansion valve (flow regulating unit)

56 latent heat removing side expansion valve (flow regulating unit)

Detailed Description

Hereinafter, embodiments of the present invention will be further described.

In the environment testing apparatus 1 of the present embodiment, an air passage 10 is provided in a lower portion of the test chamber 3. The air passage 10 communicates with the laboratory 3 through the air inlet 18 and the air outlet 16. The environment testing apparatus 1 includes an input unit, not shown, and is capable of setting a target temperature and a target humidity of the test room 3.

In the environment testing apparatus 1 of the present embodiment, the main configuration of the air conditioning apparatus 20 is disposed in the air passage 10.

The environment testing apparatus 1 of the present embodiment has a basic configuration substantially the same as that of the environment testing apparatus 100 described above, although the position of the air conditioning apparatus 20 is different. The air-conditioning apparatus 20 of the present embodiment is the same as the air-conditioning apparatus 15 of the environmental test apparatus 100 except for the configuration of the cooling unit 30.

Therefore, the same components as those of the conventional environmental test apparatus 100 are denoted by the same reference numerals, and the description thereof is simplified.

As shown in fig. 1, the environmental test apparatus 1 has a test chamber 3, a cooling unit 30, a heater 6, a humidifying device 7, and a fan 8. The laboratory 3 is a space covered with the heat insulating material 2. The air passage 10 is connected to the test chamber 3, and the evaporator (sensible heat removing evaporator 38, latent heat removing evaporator 40) of the cooling unit 30, the heater 6, the humidifier 7, and the fan 8 are provided in the air passage 10. The humidifier 7 is a device combining a humidifying heater 25 and a water tray 26, and heats and evaporates water in the water tray 26 in the humidifying heater 25.

In addition, a temperature sensor 12 and a humidity sensor 13 are provided in the vicinity of the air blowing portion 16 of the air passage 10.

When the environment testing apparatus 1 is used, the fan 8 is operated to set the inside of the air passage 10 in a ventilation state, and the air conditioning apparatus 20 is controlled so that the detection values of the temperature sensor 12 and the humidity sensor 13 approach the target temperature and the target humidity.

The environment testing apparatus 1 operates the fan 8 to introduce the air in the test room 3 from the air introduction portion 18 to the air conditioning apparatus 20 side, and adjusts the temperature and humidity by the air conditioning equipment in the air passage 10. Then, the temperature-and humidity-adjusted air is returned from the air blowing unit 16 to the test room 3, and an environment of a desired temperature and humidity is created in the test room 3.

The cooling unit 30 is a characteristic structure of the present embodiment, and is explained in detail. The cooling unit 30 used in the present embodiment is configured as a refrigeration cycle in which a refrigerant whose internal phase changes circulates, and compression, condensation, expansion, and evaporation are repeated to obtain cold and heat, as in the case of a known cooling unit.

The cooling unit 30 employed in the present embodiment has 2 evaporators.

For convenience of description, one evaporator is referred to as a sensible heat removal evaporator (difficult-to-drain heat exchanger) 38, and the other evaporator is referred to as a latent heat removal evaporator (easy-to-drain heat exchanger) 40. The sensible heat removal evaporator 38 and the latent heat removal evaporator 40 both function as cooling dehumidifiers that lower the temperature of the air and have a dehumidification function, but the sensible heat ratios of the two are different. That is, the sensible heat ratio of the sensible heat removal evaporator 38 is high, and the sensible heat ratio of the latent heat removal evaporator 40 is low.

Both the sensible heat removal evaporator 38 and the latent heat removal evaporator 40 are heat exchangers that supply a refrigerant to the inside (primary side), evaporate the refrigerant inside, and exchange heat with air passing through the air passage 10 by lowering the surface temperature.

The sensible heat removal evaporator 38 and the latent heat removal evaporator 40 are provided with

fins

41 and 42 on the surfaces thereof, as in the case of a known evaporator.

Comparing the fins 41 of the sensible heat removal evaporator 38 and the fins 42 of the latent heat removal evaporator 40, the intervals between the fins 41 of the sensible heat removal evaporator 38 are narrower than the intervals between the fins 42 of the latent heat removal evaporator 40, and the intervals between the fins 42 of the latent heat removal evaporator 40 are wider than the intervals between the fins 41 of the sensible heat removal evaporator 38.

The distance between the

fins

41 and 42 is determined in consideration of the fact that the condensed water easily flows down when the planes of the

fins

41 and 42 are held in a vertical posture as shown in fig. 3.

As shown in fig. 3, if the sensible heat removal evaporator 38 is assumed to hold the plane of the fin 41 in a vertical position, even if condensed water is generated on the surface, the condensed water is less likely to flow down and is likely to remain on the surface of the fin 41.

The sensible heat removal evaporator 38 is a heat exchanger that is difficult to drain and that relatively easily accumulates condensed water when condensed water is generated on the surface.

In the sensible heat removal evaporator 38, as shown in fig. 4(a), the water droplets a adhere to one fin 41a, and when the water droplets a grow, the water droplets B contact the adjacent fin 41B and are hard to fall, before the water droplets slide down by gravity.

Conversely, the interval SW of the fins 41 of the sensible heat removal evaporator 38 is set to a relatively narrow interval to the extent that water droplets easily contact both of the

adjacent fins

41a and 41 b.

However, it is to be avoided that water droplets are deposited densely between the

fins

41a and 41b, and the fins 41 are clogged.

Therefore, in the sensible heat removal evaporator 38, the interval between the fins 41 is set to the lowest interval at which the water droplets contact the adjacent fins 41a and 41B as in the water droplets B before they slide down by gravity, and the water droplets are hard to fall down and hardly cause clogging.

On the other hand, in the latent heat removing evaporator 40, as shown in fig. 3, the plane of the fin 42 is held in a vertical posture, and when condensed water is generated on the surface, the condensed water quickly flows down and is hard to stop on the surface of the fin 42. The latent heat removing evaporator 40 is an easy-to-drain heat exchanger that is relatively easy to drain condensed water when condensed water is generated on the surface.

As shown in fig. 4(b), even if the water droplets a adhere to the fins 42a of the latent heat removing evaporator 40 and grow, the water droplets a slide down by gravity before contacting the adjacent fins 42 b.

Conversely, the fins 42 of the latent heat removing evaporator 40 are spaced apart so widely that the water droplets do not contact both of the

adjacent fins

42a and 42 b.

The cooling unit 30 used in the present embodiment is configured as a refrigeration cycle in which a refrigerant whose internal phase changes circulates, and compression, condensation, expansion, and evaporation are repeated to obtain cold and heat, as in the case of a known cooling unit.

As shown in fig. 1 and 2, the cooling unit 30 of the present embodiment is divided into a sensible heat removal flow path 50 that branches off downstream of the condenser 36 and reaches the sensible heat removal evaporator 38, and a latent heat removal flow path 51 that reaches the latent heat removal evaporator 40.

An expansion unit (hereinafter, referred to as a sensible heat removal side expansion valve) 52, a sensible heat removal evaporator 38, and a check valve 55 are connected to the sensible heat removal flow path 50 in this order.

Similarly, the latent heat removal flow path 51 is also provided with an expansion unit (hereinafter referred to as a latent heat removal side expansion valve) 56, a latent heat removal evaporator 40, and a check valve 57, which are connected to the latent heat removal flow path 51 in this order.

Then, the sensible heat removal flow path 50 and the latent heat removal flow path 51 merge and return to the compressor 35.

The

expansion units

52 and 56 are both electronic expansion valves, which are valves capable of changing the opening degree, and function as flow rate adjusting units. The

expansion units

52, 56 can substantially close the flow path.

The cooling unit 30 used in the present embodiment, like a known cooling unit, drives the compressor 35 to circulate the refrigerant, thereby lowering the surface temperatures of the sensible heat removal evaporator 38 and the latent heat removal evaporator 40.

That is, the refrigerant gas is compressed by the compressor 35, and the refrigerant is liquefied by taking heat from the condenser 36.

Focusing on the sensible heat removal flow path 50, the refrigerant is released from the sensible heat removal side expansion valve 52 and vaporized in the sensible heat removal evaporator 38, and at this time, heat is taken from the surroundings to lower the surface temperature of the sensible heat removal evaporator 38. The refrigerant gas discharged from the sensible heat removal evaporator 38 is returned to the suction side of the compressor 35 through the check valve 55, and is compressed again.

Similarly, if attention is paid to the latent heat removal flow path 51, the refrigerant is released from the latent heat removal expansion valve 56 and vaporized in the latent heat removal evaporator 40, and at this time, heat is taken from the surroundings to lower the surface temperature of the latent heat removal evaporator 40. The refrigerant gas exiting the latent heat removal evaporator 40 returns to the suction side of the compressor 35 through the check valve 57 and is compressed again.

In the environment testing apparatus 1 of the present embodiment, as described above, the evaporators (the sensible heat removal evaporator 38 and the latent heat removal evaporator 40) of the cooling unit 30 are provided in the air passage 10 provided at the lower portion of the test chamber 3.

As shown in fig. 3, each of the 2 evaporators (sensible heat removal evaporator 38 and latent heat removal evaporator 40) is provided in such a manner that the surfaces of the

fins

41 and 42 are in a vertical posture. The surfaces of the

fins

41 and 42 are arranged in the direction along the air blowing direction.

In the present embodiment, the sensible heat removal evaporator 38 is located on the upwind side in the blowing direction, and the latent heat removal evaporator 40 is located on the downwind side.

A water receiving tray 58 is provided below the 2 evaporators (sensible heat removal evaporator 38 and latent heat removal evaporator 40). The water receiving tray 58 is provided with a drain port 60.

The environment testing apparatus 1 of the present embodiment includes the sensible heat removal evaporator 38 and the latent heat removal evaporator 40, and the refrigerant is supplied to both of them to lower the surface temperatures of both of them.

Here, attention is paid to the sensible heat removal evaporator 38 on the windward side.

When the surface temperature of the sensible heat removal evaporator 38 becomes equal to or lower than the ambient dew point temperature, water vapor in the air condenses on the surface of the sensible heat removal evaporator 38, and the condensed water adheres to the surface of the fin 41.

The condensed water gradually grows, but the sensible heat removal evaporator 38 is a heat exchanger difficult to drain, and the interval SW between the fins 41 is narrow, so that the water droplets are sandwiched between the

fins

41a, 41b as described above, and are in a state of being difficult to fall.

Therefore, when the supply of the refrigerant to the sensible heat removal evaporator 38 is stopped or the surface temperature of the sensible heat removal evaporator 38 increases, the condensed water remaining between the fins 41 is evaporated again and returned to the air.

When the surface temperature of the sensible heat removal evaporator 38 is lowered to the ambient dew point temperature or lower, water vapor in the air condenses, and the partial pressure of water vapor in the air temporarily decreases, but when the space including the laboratory 3 is observed as one system, the water changes only from the gas phase to the liquid phase, that is, the amount of water in the system does not change greatly.

Therefore, when the condensed water remaining between the fins 41 evaporates as described above, the water vapor partial pressure in the air that has temporarily decreased rises again.

Therefore, the sensible heat removal evaporator 38 is difficult to change the moisture amount in the system, and contributes little to the reduction in humidity.

The sensible heat removal evaporator 38 mainly lowers the temperature in the laboratory 3 without greatly lowering the humidity.

That is, the sensible heat removal evaporator 38 mainly functions to remove sensible heat in air, and the effect of removing latent heat in air is relatively small.

It can be said that the sensible heat removal evaporator 38 is substantially high in sensible heat ratio.

In contrast, the latent heat removal evaporator 40 has a high function of reducing the amount of moisture in the system and lowering the humidity.

When the surface temperature of the latent heat removing evaporator 40 becomes equal to or lower than the ambient dew point temperature, water vapor in the air condenses on the surface of the latent heat removing evaporator 40, and the condensed water adheres to the surface of the fin 42.

The condensed water gradually grows. Here, as shown in fig. 3 and 4(b), since the fin 42 of the latent heat removal evaporator 40 has a wide interval LW, as described above, when water droplets grow, they slide down by gravity before contacting the

adjacent fins

42a and 42b, fall to the lower tray 58, and are discharged from the drain port 60 to the outside of the environmental test apparatus 1.

The condensed water generated in the latent heat removing evaporator 40 is discharged to the outside of the system, and is difficult to vaporize in the system (for example, the air passage 10), so that the state of humidity reduction is maintained.

Further, since the latent heat removing evaporator 40 consumes a large amount of water vapor in the cold and hot condensed air, the function of reducing the temperature of the air passing through the air passage 10 is relatively low.

Thus, the latent heat removing evaporator 40 mainly functions to remove latent heat in the air.

It can be said that the latent heat removing evaporator 40 has a substantially low sensible heat ratio.

As described above, the air-conditioning apparatus 20 employed in the present embodiment is divided into the sensible heat removal flow path 50 reaching the sensible heat removal evaporator 38 and the latent heat removal flow path 51 reaching the latent heat removal evaporator 40 on the downstream side of the condenser 36. The sensible heat removal flow path 50 is provided with a sensible heat removal expansion valve 52, and the latent heat removal flow path 51 is provided with a latent heat removal expansion valve 56.

As described above, the

expansion units

52 and 56 are both electronic expansion valves, and can change the opening degree, and also function as flow rate adjusting units.

Therefore, by adjusting the opening degrees of the sensible heat removal side expansion valve 52 and the latent heat removal side expansion valve 56, the amounts of the refrigerants supplied to these can be adjusted. Further, by adjusting the opening degrees of the sensible heat removal expansion valve 52 and the latent heat removal expansion valve 56, the ratio of the refrigerant flowing to the sensible heat removal evaporator 38 and the refrigerant flowing to the latent heat removal evaporator 40 can be changed.

This makes it possible to switch between an operation in which the temperature of the air in the priority test room 3 is reduced and an operation in which the humidity of the air in the priority test room 3 is reduced.

In the present embodiment, the sensible heat ratio of the entire cooling unit 30 can be substantially adjusted in this manner.

That is, when sensible heat is desired to be obtained, the sensible heat removal expansion valve 52 is opened to increase the amount of refrigerant supplied to the sensible heat removal evaporator 38, thereby increasing the operation of the sensible heat removal evaporator 38. As a result, the sensible heat ratio of the entire cooling unit 30 increases.

When dehumidification is desired, the latent heat removal expansion valve 56 is opened to increase the amount of refrigerant supplied to the latent heat removal evaporator 40, thereby increasing the operation of the latent heat removal evaporator 40. As a result, the sensible heat ratio of the entire cooling unit 30 is reduced.

In the present embodiment, the ratio of the contribution to sensible heat removal and the contribution to latent heat removal of the cooling unit 30 can be controlled by adjusting the opening degree of the sensible heat removal side expansion valve 52 and the opening degree of the latent heat removal side expansion valve 56.

For example, it is desirable to maintain the temperature in the test chamber 3 as low as possible and only reduce the humidity as low as possible when the current temperature in the test chamber 3 is close to the target temperature and the current humidity is higher than the target humidity.

In this case, the sensible heat removal expansion valve 52 is reduced in size to reduce the amount of refrigerant supplied to the sensible heat removal evaporator 38, and the latent heat removal expansion valve 56 is opened to increase the amount of refrigerant flowing to the latent heat removal evaporator 40.

As a result, the amount of heat exchange in the sensible heat removal evaporator 38 tends to decrease, and the temperature of the air passing through the air passage 10 decreases.

On the other hand, the heat exchange amount of the latent heat removing evaporator 40 tends to increase, and more water vapor is condensed on the surface of the latent heat removing evaporator 40, so that the humidity of the air passing through the air passage 10 decreases. Further, since the condensed water is drained to the outside of the environmental test apparatus 1, the condensed water is evaporated again to reduce the increase in humidity.

In addition, since most of the cold heat generated by the latent heat removing evaporator 40 is consumed for condensation of the water vapor, the temperature decrease (decrease in sensible heat) by the latent heat removing evaporator 40 is relatively small.

As a result, the air passing through the two evaporators (sensible heat removal evaporator 38 and latent heat removal evaporator 40) is reduced in temperature as the humidity is reduced.

The air passing through the two evaporators (sensible heat removal evaporator 38, latent heat removal evaporator 40) is raised in temperature to the target temperature by the heater 6 on the downstream side, but because the temperature decrease of the air passing through the two

evaporators

38, 40 is small, the amount of heating by the heater 6 is sufficient to be relatively small. Therefore, the heater 6 consumes less power.

In contrast, when the current humidity in the test chamber 3 is close to the target humidity and the current temperature is higher than the target temperature, it is desirable to reduce only the temperature without reducing the humidity in the test chamber 3 as much as possible. In this case, the latent heat removal expansion valve 56 is reduced in size to reduce the amount of refrigerant supplied to the latent heat removal evaporator 40, and the sensible heat removal expansion valve 52 is opened to increase the amount of refrigerant flowing to the sensible heat removal evaporator 38.

As a result, the heat exchange amount of the latent heat removal evaporator 40 tends to decrease, and the condensation amount on the surface of the latent heat removal evaporator 40 decreases. Therefore, the amount of moisture discharged to the outside of the system is reduced, and the humidity of the air passing through the air passage 10 is reduced.

On the other hand, the heat exchange amount of the sensible heat removal evaporator 38 tends to increase, and the temperature of the air passing through the air passage 10 is decreased by the sensible heat removal evaporator 38.

Here, a large amount of water vapor condenses on the surface of the sensible heat removal evaporator 38 as the amount of heat exchange in the sensible heat removal evaporator 38 increases, but the condensed water tends to remain on the surface of the sensible heat removal evaporator 38. Therefore, as time passes, the water droplets on the surface of the sensible heat removal evaporator 38 evaporate, and the humidity in the laboratory 3 is restored.

The air introduced into the air passage 10 from the laboratory 3 is adjusted to a humidity as the target humidity by the humidifying device 7 on the upstream side, but because the humidity reduction of the air passing through the two

evaporators

38, 40 is small, a relatively small amount of humidification by the humidifying device 7 is sufficient. Therefore, the power consumption of the humidifier 7 is relatively small.

Next, the control of the environmental test apparatus 1 according to the present embodiment will be specifically described. In the environment testing apparatus 1 of the present embodiment, when the detection value of the temperature sensor 12 is higher than the target temperature and the detection value of the humidity sensor 13 is higher than the target humidity, the refrigerant flows through both the two evaporators (the sensible heat removal evaporator 38 and the latent heat removal evaporator 40) to lower the temperature and the humidity, and the environment in the test room 3 is brought close to the target environment.

In the environment testing apparatus 1 of the present embodiment, when the temperature in the test chamber 3 approaches the target temperature, the cooling unit 30 and the heater 6 are used together to maintain the temperature in the test chamber 3 at the target temperature. Similarly, when the humidity in the test chamber 3 approaches the target humidity, the humidity in the test chamber 3 is maintained at the target humidity by the cooling unit 30 and the humidifying device 7.

In the present embodiment, after the environment in the laboratory 3 approaches the target temperature and the target humidity, the outputs of the heater 6 and the humidification heater 25 are monitored, the ratios of the refrigerants to the two evaporators (the sensible heat removal evaporator 38 and the latent heat removal evaporator 40) are calculated from the outputs of the heater 6 and the humidification heater 25, and the opening degrees of the sensible heat removal expansion valve 52 and the latent heat removal expansion valve 56 are changed.

In the embodiment described above, as shown in fig. 2, the downstream side of the condenser 36 is branched into two paths of the sensible heat removal flow path 50 and the latent heat removal flow path 51, and the sensible heat removal evaporator 38 and the latent heat removal evaporator 40 are merged and returned to the suction side of the compressor 35 on the downstream side thereof. In the piping system shown in fig. 2, a sensible heat removal side expansion valve 52 and a latent heat removal side expansion valve 56, which function as flow rate regulating valves, are provided in the respective branch flow paths.

According to the piping system described above, the amount of refrigerant flowing through the sensible heat removal evaporator 38 and the amount of refrigerant flowing through the latent heat removal evaporator 40 can be independently and individually controlled.

Although the cooling unit 30 shown in fig. 2 is preferred, the refrigerant flowing in either of the

evaporators

38, 40 is extremely small and is sometimes normalized.

That is, depending on the application of the environment testing apparatus 1, there are many occasions when a large amount of refrigerant flows in either the sensible heat removal evaporator 38 or the latent heat removal evaporator 40. In this case, conversely, the refrigerant flowing in the

other evaporator

38, 40 is usually small in amount.

Here, when the amount of refrigerant passing through the evaporator is too small, the oil circulation may be stagnated.

In a case where such a situation is concerned, it is recommended to adopt a circuit in which the refrigerant that has passed through one evaporator and the refrigerant that has not passed through the evaporator are merged and flow to the other evaporator.

The cooling unit 72 shown in fig. 5 has a cooling circuit recommended in a case where it is expected that the amount of heat exchange by the sensible heat removal evaporator 38 is small compared to the amount of heat exchange by the latent heat removal evaporator 40.

In the cooling unit 72 shown in fig. 5, the downstream side of the condenser 36 is branched into two paths, i.e., the latent heat removal flow path 51 and the bypass flow path 63. The latent heat removal side expansion valve 56, the latent heat removal evaporator 40, and the check valve 57 are connected to the latent heat removal flow path 51 in this order.

The sensible heat removal side expansion valve 52 is connected to the bypass flow path 63.

The downstream side of the latent heat removal flow path 51 merges with the bypass flow path 63, and is connected to the sensible heat removal evaporator 38, so that the refrigerant is returned to the suction side of the compressor 35 by the sensible heat removal evaporator 38.

According to this embodiment, even if the sensible heat removal evaporator 38 requires a small amount of heat exchange and the sensible heat removal expansion valve 52 is reduced, the refrigerant passing through the latent heat removal evaporator 40 flows through the sensible heat removal evaporator 38, and therefore, a required refrigerant flow rate can be ensured.

Since the refrigerant passing through the latent heat removal evaporator 40 is basically a gas and the amount of cold and heat retained is small, it is difficult to contribute to the reduction in the surface temperature of the sensible heat removal evaporator 38.

In the above-described embodiment, the evaporators of the sensible heat removal evaporator 38 and the latent heat removal evaporator 40 are provided in one cooling circuit, and the common compressor 35 is used as a refrigerant supply source. In the above configuration, the opening degrees of the sensible heat removal side expansion valve 52 and the latent heat removal side expansion valve 56 are adjusted to adjust the amount of the refrigerant supplied to the sensible heat removal evaporator 38, the amount of the refrigerant supplied to the latent heat removal evaporator 40, and the distribution ratio.

In the above-described embodiment, after the refrigerant passing through the common condenser 36 is supplied to the sensible heat removal evaporator 38 and the latent heat removal evaporator 40, the remaining cooling capacity of the refrigerant supplied to each of the

evaporators

38, 42 is proportional to the amount of the refrigerant.

Therefore, the above-described embodiment is an evaporator in which the amount and the stored heat amount of the refrigerant supplied to the latent heat removal evaporator (easy-to-drain heat exchanger) 40 and the amount and the stored heat amount of the refrigerant supplied to the sensible heat removal evaporator (difficult-to-drain heat exchanger) 38 are different from each other.

The present invention is not limited to this configuration, and an evaporator having

individual cooling units

61 and 62 may be used as shown in fig. 6. In the embodiment shown in fig. 6, a compressor (a difficult-to-drain side refrigerant supply source) 35a as a refrigerant supply source for the sensible heat removal evaporator 38 and a compressor (an easy-to-drain side refrigerant supply source) 35b as a refrigerant supply source for the latent heat removal evaporator 40 are provided.

In the embodiment shown in fig. 6, after the refrigerants having passed through the

different condensers

36a, 36b are supplied to the sensible heat removal evaporator 38 and the latent heat removal evaporator 40, the refrigerant to be supplied to each of the evaporators may have different amounts of cold and heat retained even if the opening degrees of the sensible heat removal expansion valve 52 and the latent heat removal expansion valve 56 are the same.

The embodiment shown in fig. 6 is an evaporator in which the amount of heat retained in the refrigerant supplied to the latent heat removal evaporator (easy-to-drain heat exchanger) 40 and the amount of heat retained in the refrigerant supplied to the sensible heat removal evaporator (difficult-to-drain heat exchanger) 38 are different from each other.

Since the components constituting the cooling

units

61 and 62 of fig. 6 are common to those of the above-described embodiment, the same components are denoted by the same reference numerals and redundant description thereof is omitted.

In the embodiment described above, the space between the

fins

41 and 42 is narrowed, and the ease of storing the condensed water is changed.

This configuration is simple and is recommended because a clear difference in which condensed water is likely to accumulate can be generated.

As another method, as shown in fig. 7, a method of changing the surface shape of the fin to vary the ease of accumulation of the condensed water is considered.

Fig. 7 shows an example of a fin of the sensible heat removal evaporator 38. The fin 65 shown in fig. 7(a) has a corrugated plate shape and has a wave on the surface. Therefore, the condensed water is easily left on the upper portion of the waves.

The fin 66 shown in fig. 7(b) has a stepped shape and has a step on the surface. Therefore, the condensed water is likely to remain in the upper portion of the step.

The fin 67 shown in fig. 7(c) has fine protrusions on its surface. Therefore, the condensed water is easily retained by the projection.

The fin 68 shown in fig. 7(d) has fine openings on the surface. Therefore, a water film is generated to hold the condensed water.

Fig. 7(a), (b), and (c) show an example of a structure in which the water retention capacity is enhanced by varying the shape of the fins.

The

fins

65, 66, 67 shown in fig. 7(a), (b), and (c) all have higher water retention than the flat fins.

Therefore, it is recommended to use the

fins

65, 66, 67 shown in fig. 7(a), (b), and (c) as the fins of the sensible heat removal evaporator (difficult-to-drain heat exchanger) 38 and to use the fins with a smooth surface as the latent heat removal evaporator (easy-to-drain heat exchanger) 40.

The fin 68 shown in fig. 7(d) is a structural example in which the water retention capacity of the fin is enhanced by surface tension.

Further, as shown in fig. 8, by changing the posture of the evaporator, a clear difference can be generated in which condensed water is likely to accumulate. That is, in the example shown in fig. 8, the sensible heat removal evaporator 38 is in a horizontal posture, and the fin 41 is in a horizontal posture. Therefore, the condensed water is hard to flow, and the condensed water is likely to accumulate.

The surfaces of the

fins

41 and 42 may be coated to adjust condensed water that is likely to accumulate. For example, a hydrophobic coating may be provided to promote the flow of condensed water to form the latent heat removing evaporator 40. By providing a hydrophobic coating, the wettability of the fin with respect to water is reduced, and water is less likely to remain.

Further, a hydrophilic coating layer may be provided to prevent the flow of condensed water, thereby forming the sensible heat removal evaporator 38. The bucket is provided with a hydrophilic coating, so that the wettability of the fins to water is improved, and water is easy to remain.

For example, a hydrophilic coating is provided on the surface of the fin of the sensible heat removal evaporator (difficult-to-drain heat exchanger) 38 to improve wettability with water. Or a hydrophobic coating layer may be provided on the surface of the latent heat removing evaporator (easy-to-drain heat exchanger) 40 to reduce the wettability to water.

In the embodiments described above, the cooling units 30 are all cooling units that constitute a refrigeration cycle to reduce the surface temperature of the evaporator, but cooling units configured to circulate the antifreeze may be employed instead.

When the antifreeze is used, a heat exchanger that supplies a refrigerant such as antifreeze to the primary side and can reduce the surface temperature and exchange heat with air is used instead of the sensible heat removal evaporator 38 and the latent heat removal evaporator 40.

In the embodiment described above, the sensible heat removal evaporator 38 and the latent heat removal evaporator 40 are placed below the laboratory 3, but the positions of the sensible heat removal evaporator 38 and the latent heat removal evaporator 40 are arbitrary. For example, an air passage may be provided in the lateral direction of the laboratory 3, and air may flow through the air passage from the top to the bottom or from the bottom to the top. When an air passage is provided on the side surface of the laboratory 3 and air flows through the air passage from the bottom to the top, it is preferable that the sensible heat removal evaporator 38 be disposed on the leeward side and the latent heat removal evaporator 40 be disposed on the windward side.

In the above embodiment, the sensible heat removal evaporator 38 is disposed upstream of the air blow, but the order may be reversed.

The sensible heat removal evaporator 38 and the latent heat removal evaporator 40 may be separated from each other, or the sensible heat removal evaporator 38 and the latent heat removal evaporator 40 may be arranged side by side (horizontally).

Further, the fins of the sensible heat removal evaporator 38 and the latent heat removal evaporator 40 may be different in drainage property by combining a plurality of intervals, surface shapes, and surface treatments.

The air conditioner 20 is developed for the purpose of being mounted on the environment testing apparatus 1, but the application of the air conditioner 20 is not limited to the environment testing apparatus 1, and the air conditioner can be effectively used as an air conditioner for conditioning other environment forming apparatuses and indoor environments.

Claims

1. An air conditioning apparatus having a cooling function and a dehumidifying function, characterized in that:

has a plurality of heat exchangers for supplying refrigerant to the primary side thereof and exchanging heat with air while reducing the surface temperature thereof,

the heat exchanger includes an easy-drainage heat exchanger for easily discharging condensed water when condensed water is generated, and a difficult-drainage heat exchanger for easily accumulating condensed water compared with the easy-drainage heat exchanger,

the refrigerant can be supplied to both the easy-to-drain heat exchanger and the difficult-to-drain heat exchanger to lower the surface temperature of both the easy-to-drain heat exchanger and the difficult-to-drain heat exchanger,

the amount of refrigerant supplied to the easy-to-drain heat exchanger and the difficult-to-drain heat exchanger and/or the amount of cold and heat retained can be adjusted,

the amount of refrigerant and/or the amount of cold stored in the heat exchanger can be made different from the amount of refrigerant and/or the amount of cold stored in the heat exchanger.

2. The air conditioning unit according to claim 1, characterized in that:

the heat exchanger has fins on the surface, and the average interval of the fins is narrower in the heat exchanger with poor water drainage than in the heat exchanger with easy water drainage.

3. The air conditioning unit according to claim 1, characterized in that:

the heat exchanger has the fin on the surface, difficult drainability heat exchanger with easy drainability heat exchanger the surface shape of fin is different and the power of keeping water is different, difficult drainability heat exchanger with easy drainability heat exchanger compares, the power of keeping water of fin is higher.

4. The air conditioning unit according to claim 1, characterized in that:

the heat exchanger has fins on the surface, and the fins of the difficult-to-drain heat exchanger have better wettability with water than the fins of the easy-to-drain heat exchanger.

5. The air conditioning unit according to claim 1, characterized in that:

the water-cooling system is provided with a common refrigerant supply source, and a flow rate adjusting unit is provided in a refrigerant supply path for supplying the refrigerant from the refrigerant supply source to the easy-to-drain heat exchanger and the difficult-to-drain heat exchanger.

6. The air conditioning unit according to claim 1, characterized in that:

the heat exchanger includes an easy-drainage side refrigerant supply source for supplying the refrigerant to the easy-drainage heat exchanger and a difficult-drainage side refrigerant supply source for supplying the refrigerant to the difficult-drainage heat exchanger.

7. The air conditioning unit according to claim 1, characterized in that:

capable of setting a target temperature and a target humidity, and adjusting a current temperature and humidity within a prescribed space to the target temperature and the target humidity,

when the current temperature is close to the target temperature and the current humidity is higher than the target humidity, the amount of refrigerant and/or the remaining cooling heat supplied to the easy-to-drain heat exchanger tends to increase.

8. The air conditioning unit according to claim 1, characterized in that:

when the current temperature is higher than the target temperature and the current humidity is close to the target humidity, the amount of refrigerant and/or the remaining cooling capacity supplied to the heat exchanger having a low water-resistance and high water-resistance tends to increase.

9. The air conditioning unit according to claim 1, characterized in that:

the air blower is provided with an air blowing unit, wherein the heat exchanger difficult to drain is arranged on the upstream side of the air blowing direction, and the heat exchanger easy to drain is arranged on the downstream side of the air blowing direction.

10. The air conditioning unit according to claim 1, characterized in that:

a common refrigerant supply source for supplying a refrigerant from the refrigerant supply source to the easy-to-drain heat exchanger and the difficult-to-drain heat exchanger,

the heat exchanger includes a bypass passage for bypassing the easy-to-drain heat exchanger or the difficult-to-drain heat exchanger, and a circuit for merging the refrigerant having passed through one of the easy-to-drain heat exchanger and the difficult-to-drain heat exchanger and the refrigerant having passed through the bypass passage and flowing the refrigerant to the other heat exchanger.

11. An environmental test device which characterized in that:

comprising a laboratory for placing a test object and the air conditioner of any one of claims 1 to 10, wherein the environment in the laboratory is conditioned by the air conditioner.