JP2003279190A - Device and method for dehumidifying gas - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device and a method for dehumidifying gas capable of keeping relative humidity of gas after dehumidification in 20-30% level and capable of continuously dehumidifying without changing over flow passage of gas (air or the like). <P>SOLUTION: This device is a heat pump type dehumidifying device including an evaporator of coolant, a compressor, a condenser and a restriction mechanism. The condenser, the evaporator, and a dehumidified gas sending out opening are provided in order from a suction opening along an air flow passage. After temperature of air from the suction opening is raised by heat exchange in the condenser, the air keeps contact on surface of the evaporator to prevent frost formation and is blown out from the sending out opening with humidity in the air condensed and removed. This method is to continuously dehumidify without changing an air flow passage with keeping temperature of coolant in the evaporator 0°C or less with using the device. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is capable of dehumidifying an object to be dehumidified, such as air, to a relative humidity of 20% to 30%, and suppresses frost formation without switching the air flow path to allow continuous operation. The present invention relates to a gas dehumidifying device and a dehumidifying method using the same.

[0002]

2. Description of the Related Art A heat pump type dehumidifying device having a refrigerant compressor, a condenser, a throttle mechanism (expansion valve), and an evaporator is known. In this heat pump type dehumidifying device, a process of cooling the dehumidified object such as air in a refrigerant evaporator to condense and remove water contained in the air is taken. The refrigerant that has become high temperature by exchanging heat with the humid air in the evaporator is compressed by the compressor, and then is cooled and condensed by the dehumidified air that has been cooled by the evaporator and becomes low temperature in the condenser. The expansion valve) causes the temperature to drop and the evaporator to exchange heat with humid air to vaporize.

In this conventional dehumidifier, moisture in the air is frosted and adheres to the surface of an evaporator for condensing (liquefying) / removing moisture in the dehumidified substance, for example, liquefied (condensed) moisture. Since it freezes and reduces the heat exchange capacity in the evaporator, it is equipped with an electric heater for defrosting, or the circulating path of the refrigerant is switched to feed the hot refrigerant from the compressor directly to the evaporator for defrosting. Etc. were adopted. It is also known that the air flow path is reversed, the temperature of the air is raised by the condenser, and the hot air defrosts the evaporator for a certain period of time.

[0004]

When the defrosting means for melting the frost or ice on the surface of the evaporator is adopted by the heat source such as the electric heater, it is necessary to equip the equipment such as the electric heater and the dehumidifying device has a complicated structure. Not only does this increase cost, but it also leads to lower energy efficiency. When the dehumidifying means for melting the frost or ice on the surface of the evaporator by reversing the flow path of the object to be dehumidified, such as air, is used, the dehumidifying capacity is maintained while the air flow path is reversed and defrosting is performed. Is decreased, there is a problem that continuous and stable dehumidification cannot be performed.

Further, as a common problem in the prior art, there is a problem that the relative humidity after dehumidification: 50% to 60% is the dehumidification limit. This is because the evaporator has a problem of frost formation, and the defrosting operation is not frequently interposed during the operation, so that the refrigerant temperature in the evaporator cannot be set low.

According to the present invention, the relative humidity after dehumidification can be set to a level of 20% to 30% with a simple device configuration, and the continuous operation can be performed without switching the flow path of the dehumidified object such as air. An object of the present invention is to provide a gas dehumidifying device and a dehumidifying method using the same.

[0007]

The invention according to claim 1 for solving the above-mentioned problems is a heat pump type gas dehumidifier having a refrigerant evaporator, a compressor, a condenser, and a throttle mechanism. Then, a refrigerant condenser, an evaporator, and a dehumidifying body outlet are sequentially arranged along the circulation path of the dehumidifying body from the suction port of the dehumidifying body, and the dehumidifying body from the suction port first exchanges heat with the condenser. To raise the temperature, and then guide the high-temperature moisture-removed object after temperature rise to the evaporator, and contact the surface of the evaporator to prevent frost formation and condense / remove water in the moisture-removed object, and then the outlet It is a gas dehumidifying device configured to continuously perform a dehumidifying operation in a constant gas flow path that is blown out from.

According to a second aspect of the present invention, a refrigerant condenser, an evaporator, and a dehumidifying body sending-out port are sequentially arranged from the suction port of the dehumidifying body along the flow path of the dehumidifying body, and the object from the suction port is arranged. The dehumidifying body is first heat-exchanged by the condenser to raise the temperature, and then the high-temperature dehumidified body after the temperature rise is guided to the evaporator, and the evaporator surface is contacted to prevent frost formation and prevent A method of dehumidifying using a gas dehumidifier configured to continuously dehumidify in a constant gas flow path after condensing and removing water and then blowing out from a delivery port, wherein the temperature of the refrigerant in the evaporator is The method for dehumidifying gas is characterized in that the dehumidifying device is operated while being maintained at a temperature of 0 ° C. or lower in the vicinity thereof at all times.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below with reference to its preferred embodiments.

The following description will be given for the case where the removed moisture object is air. When removing moisture from the air using a heat pump type dehumidifier, the absolute air humidity X _∞ kg-w
The greater the difference between the ater / 1kg-air and the absolute humidity _Xw kg-water / 1kg-air with the evaporator surface temperature as the dew point, the more sufficient dehumidification is performed. Therefore, in the prior art in which the surface temperature of the evaporator cannot be set sufficiently low, the dehumidifying capacity is limited. In the present invention, the evaporator surface temperature can be set to a low value of 0 ° C. or less in the operation cycle at all times, so that the dehumidifying device and the dehumidifying method having a large dehumidifying ability can be provided.

FIG. 1 shows the structure of the gas dehumidifying device of the present invention. In FIG. 1, reference numeral 1 denotes a housing, which is a compressor 5, a condenser 3, and a throttle mechanism (expansion valve) that constitute a heat pump.
6, an evaporator 4, and a pipe for circulating a refrigerant between them are housed. Denoted at 2 is a suction port for the moisture to be removed, and in this embodiment, it is a suction port for humid air,
It is provided upstream of the condenser 3 as viewed in the air flow path.
Dehumidifying body sending-out port 7 blows out low-humidity air dehumidified by heat exchange in the evaporator 4.

Reference numeral 8 denotes a blower, which is a suction port 2 for the moisture to be removed.
It functions to form a flow path of air from the dehumidifier outlet 7. Reference numeral 9 denotes a water tray, which receives the water that has condensed in the air on the surface of the evaporator 4 (condensation) and drops, and discharges it to the outside.

In this embodiment, as shown in FIG. 1, the throttling mechanism 6 is formed of a valve and the throttling degree is adjusted by the opening / closing degree of the valve. However, a plurality of capillary tubes are provided to control the temperature. It is also possible to adopt a configuration in which the switching is performed depending on the situation.

The operation of the gas dehumidifying device of the present invention having the above structure is as follows. A refrigeration cycle is formed by the refrigerant compressor 5, the condenser 3, the expansion mechanism 6, the evaporator 4, and the pipes connecting them, and the refrigerant circulates in this system. The refrigerant exchanges heat with the air on the surface of the evaporator 4 to rise in temperature and vaporize into the compressor 5 to be pressurized and raised in temperature and fed into the condenser 3.

In the condenser 3, the high-pressure and high-temperature refrigerant exchanges heat with the humid air from the intake port 2 for the moisture to be removed to lower the temperature.
It is liquefied and further decompressed by the throttling mechanism 6 to lower its temperature and enter the evaporator 4. On the surface of the evaporator 4, the condenser 3 comes into contact with the air whose temperature has been raised by heat exchange with the high-temperature refrigerant, and the temperature of the air is lowered to condense (liquefy) the moisture in the air to dehumidify it. The refrigerant whose temperature has been raised and vaporized by heat exchange with air in the evaporator 4 is compressed by the compressor 5 to complete the refrigeration cycle, which is repeated. In the gas dehumidifying device of the present invention, the dehumidifying operation is continuously performed in a predetermined refrigeration cycle without switching the air circulation path from the dehumidified body suction port 2 to the dehumidified body discharge port 7.

The freezing (dehumidifying) cycle in the gas dehumidifying apparatus of the present invention will be described using the Mollier diagram (pressure P-enthalpy h diagram) shown in FIG. 2 in comparison with that in the prior art. In the conventional dehumidifier, the air from the suction port first comes into contact with the surface of the evaporator and is cooled to condense (condensate) the moisture in the air and drop it to remove it, thereby lowering the humidity. The high-pressure, high-temperature refrigerant from the compressor is cooled in the condenser and liquefied by the low-temperature air after dehumidification.
At the same time, the dehumidified air is heated by heat exchange with the refrigerant.

Looking at the freezing (dehumidifying) cycle in this prior art in FIG. 2, the refrigerant follows the cycle of abcd. However, when the temperature of the air to be dehumidified is relatively low, the condensed (condensed) moisture on the evaporator surface freezes at the cd (evaporator) portion in the cycle, which hinders the heat exchange capacity of the evaporator. Therefore, if hot air is blown onto the surface of the evaporator or it is heated with an electric heater or the like to melt frost or ice adhering to the surface of the evaporator, the cycle is ab-c'-d '.
, And the dehumidifying ability decreases during that time. Therefore, in the prior art, the refrigerant temperature and the evaporator surface temperature could not be made sufficiently low in order to avoid frequent frost and ice melting processes.

The dehumidifying amount of air in the heat pump type dehumidifying device is the absolute humidity of air X _∞ kg-water / 1 kg-air
When, proportional to the difference between the absolute humidity _{X w kg-water / 1kg-} air when the saturated water vapor corresponding to the evaporator surface temperature t _w is that there (X _∞ -X _w). Moreover, the absolute humidity of the air after dehumidification is asymptotic to X _w . Therefore, it is desirable to set the temperature of the refrigerant in the evaporator as low as possible. According to the above conventional technique, the relative humidity of the air after dehumidification is set to 50 due to the fact that the evaporation temperature of the refrigerant cannot be made sufficiently low.
% To 60% or less is difficult.

In the gas dehumidifying apparatus and the dehumidifying method using the same of the present invention, the air from the suction port 2 for the dehumidified substance is first heat-exchanged with the high-temperature refrigerant in the condenser 3 to be heated. Next, the hot and humid air comes into contact with the surface of the evaporator 4 and undergoes heat exchange to lower the temperature. The surface of the evaporator 4 is constantly blown with high-temperature moist air, and according to the conventional technique, the frost and ice are always melted and adhere to the surface of the evaporator even under the condition that frost or ice adheres to the surface of the evaporator. There is no. Therefore, a stable continuous dehumidifying operation can be performed even at a low evaporator surface temperature where frost or dew may freeze. As seen in the Mollier diagram shown in FIG. 2, e which is lower than the cycles a-b-c-d in the prior art.
Continuous operation becomes possible in the cycle of -f-g-h.

FIG. 3 shows the transition of the air temperature in the air flow path, the evaporator surface temperature, and the evaporator surface temperature in the gas dehumidifying apparatus of the present invention.
And the refrigerant temperature in the evaporator is shown in contrast to that in the prior art.

Although the temperature of the air decreases from the inlet to the outlet of the evaporator, it remains at a higher temperature level than in the prior art by the gas dehumidifying apparatus and method of the present invention. The temperature of the refrigerant is c in FIG.
Corresponding to -d (prior art) and gh (present invention), the refrigerant temperature can be lower in the case of the present invention. In the present invention, since the refrigerant temperature can be set low, the evaporator surface temperature becomes lower than that in the conventional dehumidifier. In the present invention, as already described, even when frost or ice is about to adhere to the surface of the evaporator, the high-temperature air from the condenser 3 is constantly blown so that the frost and ice are melted and there is no frost formation. .

As a result, the saturated vapor pressure corresponding to the temperature t _w of the evaporator surface and the absolute humidity in that case X _w kg-water /
1kg-air decreases, absolute air humidity X _∞ kg-water / 1kg-a
The difference from ir becomes large, the dehumidification capacity becomes large, and the humidity of the air after dehumidification can be greatly reduced.

[0023]

According to the present invention, the relative relative humidity reached by the prior art is 50% to 60 with a simple device configuration.
%, Reachable relative humidity: levels of 20% to 30% are possible. Further, continuous dehumidification operation can be performed without switching the distribution path of the object to be dehumidified, for example, air, while maintaining a large dehumidifying capacity and low-humidity air delivery.
Thus, the present invention can be applied to the manufacturing of chemicals, the manufacturing of electronic parts, the factories such as computers, which require a low relative humidity of 20% to 30%. Further, it can be applied to dry laundry in winter.

According to the second aspect of the invention, the absolute humidity X _∞ kg-water / 1k of the object to be removed (air, etc.) is set by always setting the refrigerant temperature in the evaporator to 0 ° C. or lower.
g-air and the evaporator surface temperature t absolute humidity in the case where the saturated water vapor is present corresponding to _{w X w kg-water / 1kg} -air
Can be sufficiently large, and continuous dehumidification operation can be performed while delivering a substance to be dehumidified (air or the like) having a large dehumidifying capacity and a low relative humidity level.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing the configuration of a gas dehumidifying device of the present invention.

FIG. 2 is a Mollier diagram showing the refrigeration cycle of the gas dehumidifier of the present invention in comparison with that of the prior art.

FIG. 3 is a graph showing changes in air temperature, evaporator surface temperature, and refrigerant temperature in the case of using the gas dehumidifying device of the present invention, in comparison with those in the related art.

[Explanation of symbols]

1 case 2 Suction port for moisture to be removed 3 condenser 4 evaporator 5 compressor 6 Aperture mechanism 7 Dehumidifier outlet 8 blower 9 water saucer

Claims (2)

[Claims] 1. A heat pump type gas dehumidifying device having a refrigerant evaporator, a compressor, a condenser, and a throttle mechanism, wherein the refrigerant is sequentially drawn from a suction port of the dehumidified object along a flow path of the dehumidified object. A condenser, an evaporator, and a dehumidifying body outlet are provided, and the dehumidifying body from the suction port is first heat-exchanged by the condenser to raise the temperature, and then the high-temperature dehumidifying body after heating is guided to the evaporator. , Which is configured to be continuously dehumidified in a constant gas flow path after being condensed and removed from the moisture-removed object while being brought into contact with the surface of the evaporator to prevent frost formation and then blown out from the outlet. Dehumidifier for gas. 2. A refrigerant condenser, an evaporator, and a dehumidifying body outlet are sequentially arranged from the suction port of the dehumidifying unit along the flow path of the dehumidifying unit, and the dehumidifying unit from the suction port is first condensed by the condenser. After heat exchange to raise the temperature, then guide the high-temperature dehumidified object after temperature rise to an evaporator and condense / remove water in the dehumidified object while contacting the evaporator surface to prevent frost formation A dehumidifying method using a gas dehumidifier configured to continuously perform dehumidifying operation in a constant gas flow path, which is blown out from a delivery port, wherein the temperature of the refrigerant in the evaporator is substantially constant during dehumidifier operation. A method for dehumidifying gas, which is characterized in that it is operated while being maintained at 0 ° C or less.