JP2694505B2 - Cooled compressed air dehumidifier - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a cooling type compressed air dehumidifying device.

[0002]

2. Description of the Related Art Conventionally, as a cooling type compressed air dehumidifier, as shown in FIG. 8, a compressor 6, a condenser 5, a capillary tube 8 as a pressure reducing means and a finned evaporator 2 are connected by refrigerant tubes 7 and 9. A refrigeration cycle evaporator 2 connected in circulation is installed in the heat exchanger 1, and hot compressed air is introduced into the heat exchanger 1 from the air inlet 1a of the heat exchanger 1 and dehumidified and cooled discharged from the air outlet 1b. The air is guided to the condenser 5 through the air take-out pipe 3 and is heated by the heat of condensation of the refrigerant through the inside of the air passage 5a connected in parallel with the condenser tube 5b through the cooling fins 5c of the condenser 5. Has been invented and is known (Japanese Utility Model Publication No. 55-24636).
In such an apparatus, the relative humidity of the discharged air is reduced by reheating the air that has been cooled and dehumidified in the heat exchanger 1 by the heat of condensation.

[0003]

However, in such a conventional device, although heat is conducted through the fins connected to the condenser tube of the condenser, the refrigerant and the compressed air actively exchange heat. However, it has the disadvantage that the heat exchange rate is poor. In addition, since the heat exchanger and the condenser are separately configured to perform heat exchange separately, there is a disadvantage that the size of the entire apparatus is increased.
The present invention has been made in view of the drawbacks of the related art, and provides an apparatus capable of performing a positive heat exchange between condensation heat and cooling air and reducing the size of the apparatus as a whole. The purpose is to:

[0004]

That is, the present invention is circulated through a refrigerant pipe to a compressor, a primary heat exchanger consisting of double piping, a pressure reducing means and a secondary heat exchanger consisting of double piping. A refrigeration cycle and an outer pipe of the secondary heat exchanger and an inner pipe of the primary heat exchanger are connected in communication with each other, and a refrigerant is provided on the outer circumference of the inner pipe of the primary heat exchanger and the inner pipe of the secondary heat exchanger. Is configured to flow, and is configured to flow hot compressed air from the outer tube of the secondary heat exchanger to the inner tube of the primary heat exchanger,
This object is achieved by a cooling type compressed air dehumidifying device configured to insulate the secondary heat exchanger from the outside and to blow outside air from the fan to the outer periphery of the primary heat exchanger. Here, the primary heat exchanger is made to act as a condenser of the refrigeration cycle to condense the refrigerant. According to the second aspect of the present invention, the heat exchange rate is increased by providing heat exchange fins on the outer circumference of the outer tube forming the primary heat exchanger. According to the third aspect of the present invention, the inner pipe through which the compressed air that constitutes the primary heat exchanger flows is formed of a twisted pipe, so that the refrigerant gas flows evenly around the outer periphery of the inner pipe. According to the fourth aspect of the present invention, the heat exchange rate is increased by making the refrigerant flowing in the inner pipe of the secondary heat exchanger and the compressed air flowing in the outer pipe counterflow. According to a fifth aspect of the present invention, when the inner pipe of the primary heat exchanger and the outer pipe of the secondary heat exchanger are communicated with each other, the drain trap is connected to discharge the drain condensed in the secondary heat exchanger. I chose According to the invention of claim 6, the temperature detecting means is provided on the outlet side of the primary heat exchanger, and the fan is rotated only when the detected temperature is equal to or higher than a predetermined temperature. The fan was prevented from rotating unnecessarily when it condensed.

[0005]

In the device according to the present invention, the refrigerant flows through the outer circumference of the inner tube of the primary heat exchanger and the inner tube of the secondary heat exchanger, and the outer circumference of the inner tube of the secondary heat exchanger and the inner part of the primary heat exchanger. The compressed air flows in the pipe. Therefore, when the refrigeration cycle is operated while supplying compressed air, the refrigerant is generated by the cooling air flowing in the inner pipe flowing from the secondary heat exchanger and the outside air flowing in the outer pipe on the outer periphery of the inner pipe of the primary heat exchanger. Is condensed. The condensed refrigerant is guided to the inner tube of the secondary heat exchanger via the pressure reducing means, and is evaporated there to function as a cooling tube. High-temperature compressed air flows in the outer periphery of the inner tube, for example, in the form of a counterflow, so that the refrigerant and the high-temperature compressed air are actively heat-exchanged, the compressed air is cooled, and the refrigerant is heated. The heated refrigerant returns to the compressor again. Further, the cooled compressed air is dehumidified and cooled by dew condensation of excess moisture because the dew point temperature decreases. The condensed water is discharged outside as drain water. The dehumidified and cooled compressed air flows through the inner tube of the primary heat exchanger, is heated and exchanged by the high-temperature refrigerant flowing around the outer periphery of the inner tube, and is discharged from the primary heat exchanger as air having a low relative humidity. . In the case where the heat exchange fins are provided on the outer periphery of the outer tube of the primary heat exchanger, heat is efficiently exchanged with air blown by a fan flowing on the outer periphery of the outer tube. In the case where the inner pipe of the primary heat exchanger is formed of a twisted pipe, the refrigerant flowing around the outer circumference of the twisted inner pipe flows in a swirling flow state, so that the refrigerant uniformly exchanges heat with the compressed air. .

[0006]

FIG. 1 is a schematic circuit diagram of an apparatus according to an embodiment of the present invention, in which a compressor 12, a primary heat exchanger 14, a pressure reducing means, a capillary tube 16 and a secondary heat are provided via a refrigerant pipe 10. Circularly connected to the exchanger 18. The primary heat exchanger 14 has a double pipe structure composed of an inner pipe 14a made of a twisted pipe and an outer pipe 14b, and a heat exchange fin 15 is attached to the outer periphery of the outer pipe 14b. 14a and outer tube 14
The cooling medium connected to the cooling medium pipe 10 is configured to flow in the space between b and b. The secondary heat exchanger 18 has a double-pipe structure including an inner pipe 18a made of a refrigerant pipe and an outer pipe 18b, and the outer periphery of the secondary heat exchanger 18 is covered with a heat insulating material 20. The outer pipe 18b of the secondary heat exchanger 18 and the inner pipe 14a of the primary heat exchanger 14 are connected via a drain trap 22. Then, compressed air is supplied from the outer tube 18 of the secondary heat exchanger 18 and discharged from the inner tube 14a of the primary heat exchanger 20 on the right side in the figure. The refrigerant circulates through the refrigerant tube 10 to the compressor 12, the outer tube 14b of the primary heat exchanger 14, the capillary tube 16, and the inner tube 18a of the secondary heat exchanger 18.

Reference numeral 21 is a fan for guiding the outside air to the primary heat exchanger 14 for air cooling. The fan 21 is connected to a temperature detecting means 24 provided on the refrigerant outlet side of the primary heat exchanger to detect the detected temperature. Control means for giving a rotation output instruction when the temperature is equal to or higher than a predetermined temperature 26
It receives electric power from the machine and rotates.

Next, FIG. 2 shows a front view of the entire cooling type compressed air dehumidifier, the side surface of which is a casing 28.
An air intake port 30 is provided on the lower front side, and the drain trap 22 projects to the outside. As shown in FIG. 3, a fan 32 for air blowing is installed in the casing 28 on the side of the air intake 30, and the duct 34 divides the air blowing path toward the outer periphery of the side surface of the compressor 12 to blow air. It is configured. The ceiling portion of the casing 28 is open, and a corner material 36 connected to the corner of the ceiling portion and a heat insulating material 38 having a radius on the side surface installed at the center form a U-shaped air passage 40. ing. The cross-sectional area of the air passage 40 is configured to be narrower than the cross-sectional area of the air intake port 30, so that the flow velocity of the air passing through the air passage 40 is increased. The U-shaped passage 40 is provided with the primary heat exchanger.
The secondary heat exchanger 18 is installed by bending 14 into a U-shape and is installed inside the heat insulating material 38 located inside the passage 40. In the present embodiment, the secondary heat exchanger 18 is configured so that the downstream side of the compressed air is lower, and the outer tube 18 b is connected to the drain trap 22. Reference numeral 42 is an adapter installed on the drain trap 22 and connects the outer pipe 18b of the secondary heat exchanger 18 with the drain trap 22 and the drain trap 22 with the inner pipe 14a of the primary heat exchanger 14. The outer tube 14b of the primary heat exchanger 14 is closed, and the refrigerant tube 10 functions as a condenser by being connected to both ends thereof.

In the embodiment of FIG. 3, a baffle plate 44 and a bottom plate 46 are provided behind the compressor 12 in the casing 28 (downstream of the wind).
It is installed vertically on the upper side, and the wind blown from the fan 32 due to the influence of the baffle plate 44 is forced to change its direction to the ceiling direction, so that it is discharged from the air passage 40 to the outside of the casing 28. Is configured.

In the configuration described above, the device according to the present embodiment operates as follows. First, fan 32
The outside air (30 ° C.) sucked by the compressor 12 is blown out toward the compressor 12 and slightly heated by the heat of compression of the compressor 12 (32 ° C.). The direction is changed and air is blown toward the ceiling of the casing 28. The changed air is blown out of the machine from the air passage 40. On the other hand, when the refrigeration cycle is activated and compressed air is supplied, high-temperature compressed air of approximately 35 ° C. flows in from the outer tube 18 b of the secondary heat exchanger 18, and flows opposite to the refrigerant flowing through the inner tube 18 a of the secondary heat exchanger 18. Heat is exchanged in the form of and cooled to approximately 10 ° C. By cooling to 10 ° C, moisture in the air will condense and the dew point temperature of the air will decrease. The condensed drain water is stored in the drain trap 22 via the adapter 42 because the downstream side of the air of the secondary heat exchanger 18 is formed low. The air dehumidified and cooled in the secondary heat exchanger 18 (10
(° C.) is guided to the twisted inner tube 14a of the primary heat exchanger 14 and discharged through the inner tube 14a. At this time, since the 80 ° C. refrigerant supplied from the compressor 12 flows in the counterflow in the outer circumference of the inner pipe 14 a, the refrigerant is directly exchanged with the refrigerant and heated to about 40 ° C.

On the other hand, refrigerant supplied from compressed air (80 ° C.)
Flows on the outer circumference of the inner pipe 14a of the primary heat exchanger 14, but because the inner pipe 14a is formed of a twisted pipe, the refrigerant gas flows as a swirling flow while stirring the refrigerant gas without stagnation. Therefore, heat is uniformly exchanged with the compressed air flowing through the inner pipe 14a, and the outer circumference of the outer pipe 14b is
Since the air blown from the side flows perpendicular to the flow of the refrigerant, the air is also exchanged with heat and cooled to about 45 ° C,
Condensed.

The condensed refrigerant flows into the capillary tube 16
After being decompressed in (1), it is guided to the inner pipe 18b of the secondary heat exchanger 18 and flows in the inner pipe 18b as a refrigerant of about 7 ° C. The refrigerant flowing in the inner pipe 18b is heated by exchanging heat with the high-temperature compressed air flowing in the counterflow in the outer circumference of the inner pipe. Then, the heated refrigerant returns to the compressor 12 again. Further, since the secondary heat exchanger 18 is mounted in the heat insulating material 20, heat is exchanged without being affected by other environments such as outside air.

In the refrigeration cycle, the primary heat exchanger 14
Temperature detection means 24 is provided on the discharge side of the air blower 21 through the control means 26 when the temperature of the refrigerant reaches a predetermined temperature or higher.
To rotate. Then, even if there is no state where the refrigerant gas is cooled by heat exchange by the cooling air in the primary heat exchanger 14 because compressed air is not supplied, it will be cooled by the air blown from the blower fan 21, and the refrigeration cycle The load condition can be avoided.

Test Example By observing the heat balance condition when the compressed refrigerant air is made to flow in the apparatus shown in FIG. 2 of the present embodiment under the following conditions, it is not necessary to provide a condenser separately in the refrigeration cycle. I confirmed whether or not. Conditions 1) Compressed air Air volume: 720 l / min. Secondary heat exchanger inlet temperature: 35 ° C (saturated) Secondary heat exchanger inlet pressure: 7 kg / cm ² G Secondary heat exchanger outlet temperature: 10 ° C ( Saturation) Primary heat exchanger outlet temperature: 50 ° C 2) Refrigeration cycle Compressor cooling capacity: 250 Kcal / h Condensing temperature: 7 ° C (primary heat exchanger refrigerant outlet temperature) Evaporation temperature: 50 ° C 3) Fan Air volume: 5 m ³ / min. Inlet temperature: 30 ° C Outlet temperature: 30.5 ° C Calorie of each part measured 1) Secondary heat exchanger (heat dissipation) Inlet air enthalpy (i ₁ ): 11.1 kcal / kg Outlet air enthalpy (i ₂ ): 4.4 kcal / kg Calorie of inner tube 18a (cooler): 190 kcal / h (35 ° C ~
2) Primary heat exchanger (endothermic) Calorific value of primary heat exchanger: 230 kcal / h (10 ° C ~
3) Refrigeration cycle side Cooling capacity of compressor: 250 kcal / h Heat exhaust heat of compressor: 310 kcal / h (cooling capacity x 1.2)
4) Fan 150kcal / h Load (when supplying compressed air) Secondary heat exchanger Primary heat exchanger Compressed air side 190kcal / h 230kcal / h Refrigeration cycle side 250kcal / h 310kcal / h Blower fan-150kcal / H No load (when compressed air is not supplied) Secondary heat exchanger Primary heat exchanger Compressed air side 0kcal / h 0kcal / h Refrigeration cycle side 0kcal / h 60kcal / h Blower fan-150kcal / h Evaluation As above The exhaust heat of the refrigeration cycle contributes to the reheating of the compressed air under load and contributes to the heating of the air blown from the blower fan at no load. Therefore, the refrigeration cycle functions in both a no-load condition and a load condition, in which a separate condenser does not need to be provided, and it has been found that there is no need to separately provide a condenser in the refrigeration cycle.

[0015]

As described above, in the device according to the present invention, the cooling and reheating of the compressed air are exchanged with the refrigerant through the double-pipe heat exchanger, so that the heat exchange efficiency of the conventional device is improved. Better than the ones. Since the compressor and the primary heat exchanger can be cooled by one blower fan, the number of blower fans can be reduced. In addition, since the dehumidifying cooling is configured by installing two heat exchangers of double piping system, the size of the device is larger than that of the dehumidifying cooling device having the conventional heat exchanger and the general condenser. Can be made smaller. Further, since the heat exchange between the refrigerant and the compressed air in the primary heat exchanger and the secondary heat exchanger is performed by the counter flow, the heat exchange efficiency is further enhanced. When the inner pipe of the primary heat exchanger is formed of a twisted pipe, the refrigerant gas flowing around the outer circumference becomes a swirl flow, and efficient heat exchange can be performed without causing the refrigerant gas to stay. With a structure in which temperature detection means is provided on the discharge side of the primary heat exchanger of the refrigeration cycle and the rotation of the blower fan is controlled, heat can be exchanged without turning the blower fan unnecessarily, thus saving energy. It is possible to reduce the load on the refrigeration cycle by rotating the fan when there is no load.

[Brief description of the drawings]

FIG. 1 is a schematic circuit diagram of an apparatus according to an embodiment of the present invention.

FIG. 2 is a front view of the device according to the embodiment.

3 is a cross-sectional view of the device of FIG. 2 taken along the line AA.

FIG. 4 is a partial perspective plan view of the device.

5 is a partial sectional view taken along line BB of the apparatus of FIG.

6 is a cross-sectional view taken along line CC of the device of FIG.

7 is a cross-sectional view of the device of FIG. 3 taken along the line D-D.

FIG. 8 is a schematic circuit diagram showing a conventional technique.

[Explanation of symbols]

 1 Heat Exchanger 2 Evaporator 3 Air Extraction Tube 4 Drain Trap 5 Condenser 5a Air Passage 5b Condensing Tube 5c Cooling Fin 6 Compressor 7,9 Refrigerant Tube 8 Capillary Tube 10 Refrigerant Tube 12 Compressor 14 Primary Heat Exchanger 14a Inside Tube 14b Outer tube 15 Heat exchange fin 16 Decompression means 18 Secondary heat exchanger 18a Inner tube 18b Outer tube 20 Insulation material 21 Blower fan 22 Drain trap 24 Temperature detecting means 26 Control means 28 Casing 30 Air intake 32 Blower fan 34 Duct 36 Corner material 38 Insulation material 40 Air passage 42 Adapter 44 Baffle board

Claims (6)

(57) [Claims] 1. A refrigeration cycle and a secondary heat exchanger circulated through a compressor, a primary heat exchanger consisting of double pipes, a pressure reducing means and a secondary heat exchanger consisting of double pipes through a refrigerant pipe. The outer pipe and the inner pipe of the primary heat exchanger are connected in communication with each other, the refrigerant is configured to flow through the outer periphery of the inner pipe of the primary heat exchanger and the inner pipe of the secondary heat exchanger, and the secondary It is configured to flow hot compressed air from the outer tube of the heat exchanger to the inner tube of the primary heat exchanger, insulates the secondary heat exchanger from the outside, and blows the outside air from the fan to the outer periphery of the primary heat exchanger. Cooling type compressed air dehumidifier configured as described above. 2. The cooling type compressed air dehumidifying device according to claim 1, wherein heat exchange fins are provided on the outer circumference of the outer tube constituting the primary heat exchanger. 3. The cooling type compressed air dehumidifying device according to claim 1, wherein the inner tube of the primary heat exchanger through which the compressed air flows is a twisted pipe. 4. The cooling type compressed air dehumidifying device according to claim 1, wherein the refrigerant flowing in the inner pipe of the secondary heat exchanger and the compressed air flowing in the outer pipe are opposed to each other. 5. The cooling type compressed air dehumidifying device according to claim 1, wherein a drain trap is connected when the inner pipe of the primary heat exchanger and the outer pipe of the secondary heat exchanger are communicated with each other. 6. The cooling compressed air according to claim 1, wherein temperature detecting means is provided on the outlet side of the primary heat exchanger, and the fan is rotated only when the detected temperature is equal to or higher than a predetermined temperature. Dehumidifier.