JP2002318015A - Freezer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a freezer capable of being reduced in manufacturing cost and power consumption. SOLUTION: The freezer comprises a refrigerant-reheating means 26 for exchanging heat between a low-temperature refrigerant discharged from an evaporator and a high-temperature refrigerant, compressed by a compressor to be transferred under pressure toward a condenser. The refrigerant-reheating means 26 has a double pipe structure of an inner pipe 42, through which one of the refrigerants flows, and an outer pipe 41, through which the other refrigerant flows outside the inner pipe 42 inserted therein. Furthermore, a spiral groove S1 is formed on the outer surface of the inner pipe 42 or on the inner surface of the outer pipe 41.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerating apparatus used for a compressed air dehumidifier, a cooler, and the like.

[0002]

2. Description of the Related Art As an apparatus provided with this type of refrigeration apparatus,
A dehumidifier 51 shown in FIG. 8 is conventionally known. The dehumidifying device 51 includes a heat exchanger 2 for dehumidifying by condensing moisture contained in compressed air that is pressure-fed by an air compressor (not shown), and a refrigeration mechanism 53 as a refrigeration device for cooling the compressed air. It has. In this case, the heat exchanger 2 is configured so that the compressed air introduced from the inlet 2a can be discharged from the outlet 2b through a gas flow path including the primary cooling unit 11, the secondary cooling unit 12, and the reheating unit 13. ing. On the other hand, the refrigeration mechanism 53 includes the secondary cooling unit 1 of the heat exchanger 2.
2, an evaporator 21 for cooling the compressed air by the heat of vaporization of the refrigerant, and a compressor 22 for pumping the vaporized refrigerant.
And a condenser 2 for condensing and liquefying the compressed vaporized refrigerant.
3, a liquid receiver 24 for temporarily storing the liquefied refrigerant, an expansion valve 25 for lowering the liquefied refrigerant, an accumulator 57 disposed between the evaporator 21 and the compressor 22, and a discharge by the compressor 22. Pipe 61a connecting the evaporator 21 and the accumulator 57 to a part of the high-pressure vaporized refrigerant to be used.
And a control valve 28 that discharges according to the suction pressure of the compressor 22.

In the dehumidifier 51, first, the compressor 22
Is driven to circulate the refrigerant in the refrigeration mechanism 53. At this time, the liquefied refrigerant in the liquid receiver 24 passes through the expansion valve 25 and is discharged into the evaporator 21, and the liquefied refrigerant is vaporized in the evaporator 21. 12 is cooled. By driving an air compressor (not shown) in this state, compressed air containing moisture is introduced from the inlet 2a. In this case, the compressed air introduced into the heat exchanger 2 is pre-cooled when passing through the primary cooling unit 11, and then, when passing through the secondary cooling unit 12, has a predetermined dew point temperature by the evaporator 21. It is cooled below. At this time, moisture in the compressed air is condensed on the surfaces of the fins attached to the evaporator 21 as dew water.
It flows down toward the bottom of the tank and is discharged outside through the drain outlet. On the other hand, when the compressed air dehumidified in the secondary cooling unit 12 passes through the reheating unit 13, it is reheated by the compressed air introduced from the inlet 2a and is discharged from the outlet 2b. Further, the vaporized refrigerant vaporized in the evaporator 21 is sucked by the compressor 22, and reaches the compressor 22 via the connecting pipe 61a, the accumulator 57, and the connecting pipe 61b as indicated by an arrow A11, and is compressed. Compressed by the press 22. Further, the compressed vaporized refrigerant is pressure-fed inside the connecting pipe 62 toward the condenser 23 as indicated by an arrow A12.

On the other hand, for example, when the load is low, the flow rate of the compressed air introduced into the heat exchanger 2 is small, so that the amount of the refrigerant vaporized in the evaporator 21 is reduced. And evaporator 21 in a state where
Is discharged from. In this case, when the liquefied refrigerant is sucked into the compressor 22, the hydraulic oil attached to the drive shaft of the compressor 22 or the like is washed away by the liquefied refrigerant, or the compressor 22 is suddenly stopped by a so-called water hammer phenomenon. The compressor 22 is damaged due to the damage. Therefore, in the refrigerating mechanism 53, the accumulator 57 is provided between the evaporator 21 and the compressor 22, and the vaporized refrigerant and the liquefied refrigerant are separated in the accumulator 57. Therefore, the liquefied refrigerant is stored in the accumulator 57, and only the vaporized refrigerant is sucked into the compressor 22.
Further, in a state where the amount of refrigerant vaporized in the evaporator 21 is reduced, the suction pressure of the vaporized refrigerant falls outside the set pressure range predetermined in the refrigeration mechanism 53 and becomes low. At this time, by opening the control valve 28 in response to the decrease in the suction pressure, a part of the high-temperature and high-pressure vaporized refrigerant discharged from the compressor 22 is passed through the connecting pipe 35 as indicated by an arrow A13. And is discharged to the connecting pipe 61a. Thereby, the suction pressure of the refrigerant is adjusted to a predetermined pressure. At the same time, the compressor 22
High-temperature and high-pressure vaporized refrigerant discharged from the accumulator 5
7, the liquefied refrigerant stored in the accumulator 57 is gradually evaporated and sucked into the compressor 22.

[0005]

However, the conventional refrigeration mechanism 53 has the following problems. That is, in the conventional refrigeration mechanism 53, the vaporized refrigerant and the liquefied refrigerant discharged from the evaporator 21 are accumulated in the accumulator 57 in order to prevent the compressor 22 from being damaged due to the liquefied refrigerant being sucked into the compressor 22. Are separated by In this case, even if a large amount of the liquefied refrigerant is discharged from the evaporator 21, all of the liquefied refrigerant must be stored in the accumulator 57. There is. For this reason, there is a problem that the manufacturing cost of the refrigeration mechanism 53 is rising due to the component cost of the large accumulator 57. Also,
In the conventional refrigeration mechanism 53, the liquefied refrigerant stored in the accumulator 57 is gradually evaporated by discharging part of the high-temperature and high-pressure vaporized refrigerant discharged from the compressor 22 to the connection pipe 61a. For this reason, when a large amount of liquefied refrigerant is discharged from the evaporator 21, in order to sufficiently evaporate the large amount of liquefied refrigerant stored in the accumulator 57,
It is necessary to always open the control valve 28 to discharge a large amount of high-temperature and high-pressure vaporized refrigerant. Therefore, even when the load is low, the compressor 22 must be driven in the same manner as at the time of the steady load. Because of the circulation of the refrigerant, there is also a problem that power consumption is large.

[0006] The present invention has been made in view of the above problems, and has as its main object to provide a refrigeration apparatus capable of reducing manufacturing costs and power consumption.

[0007]

According to a first aspect of the present invention, there is provided a refrigeration apparatus comprising: a low-temperature refrigerant discharged by an evaporator; and a high-temperature refrigerant compressed by a compressor and pumped toward a condenser. A refrigeration apparatus including a refrigerant reheating unit that exchanges heat between the refrigerant, wherein the refrigerant reheating unit includes an inner pipe through which one of the two refrigerants passes, and an inner pipe that is inserted through the inner pipe. An outer pipe through which either of the two refrigerants passes between the pipe and the outer pipe is formed in a double pipe structure, and a spiral groove is formed on the outer peripheral surface of the inner pipe or the inner peripheral face of the outer pipe. It is characterized by comprising.

According to a second aspect of the present invention, in the refrigeration apparatus according to the first aspect, the refrigerant reheating means includes an outermost portion on an outer peripheral surface of the inner tube and an innermost portion on an inner peripheral surface of the outer tube. A helical flow path is formed by the groove by being brought into contact with and connected to the peripheral portion.

According to a third aspect of the present invention, in the refrigerating apparatus according to the first or second aspect, the refrigerant reheating means is configured such that the inner pipe is formed of a torsion pipe and the outer pipe is formed of a straight pipe. It is characterized by being.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a compressed air dehumidifier equipped with a refrigeration apparatus according to the present invention will be described below with reference to the accompanying drawings. Note that the same components as those of the conventional dehumidifier 51 are denoted by the same reference numerals, and redundant description will be omitted.

First, the structure of the dehumidifying apparatus 1 will be described with reference to FIG.
This will be described with reference to FIG.

As shown in FIG. 1, a dehumidifier 1 includes a heat exchanger 2, a refrigerating mechanism 3 corresponding to a refrigerating device in the present invention,
A control unit 4 and a cooling fan FN are provided. The heat exchanger 2 is formed into a cylindrical shape as a whole, and has an inlet 2a for introducing compressed air, and an outlet 2 for discharging dehumidified compressed air.
b. Further, a gas flow path including a primary cooling unit 11, a secondary cooling unit 12, and a reheating unit 13 is formed inside the heat exchanger 2, and the compressed air introduced from the inlet 2a is supplied to the gas flow path. After being cooled and dehumidified inside, it is reheated and thereafter discharged from the discharge port 2b.

On the other hand, the refrigeration mechanism 3 includes an evaporator 21, a compressor 22, a condenser 23, a liquid receiver 24, an expansion valve 25, a refrigerant reheat pipe 26, an accumulator 27, and a control valve 28. Further, the refrigeration mechanism 3 includes a sensor PS for detecting the pressure of the vaporized refrigerant compressed by the compressor 22. The sensor PS outputs a sensor signal corresponding to the detected pressure to the control unit 4. In response to this, as described later, the control unit 4 rotates the cooling fan FN.

The refrigerant reheat pipe 26 corresponds to a refrigerant reheat means in the present invention, and as shown in FIG. 2, passes a low-temperature low-pressure refrigerant discharged from the evaporator 21 (low-temperature refrigerant in the present invention). A straight pipe 41 and a torsion pipe 42 disposed in the straight pipe 41 and passing a high-temperature and high-pressure refrigerant (high-temperature refrigerant in the present invention) discharged from the compressor 22 are formed in a double pipe structure. . The straight pipe 41 corresponds to the outer pipe in the present invention, and is formed in a cylindrical shape as a whole. As shown in FIG. 3A, the straight pipe 41 has an evaporator 21.
An inlet 41a and an outlet 41b for connecting the connecting pipe 31 (see FIG. 2) connected to the connecting pipe 32a (see FIG. 2) connected to the accumulator 27 are formed by burring. I have.

On the other hand, the torsion tube 42 corresponds to the inner tube in the present invention, and has a slightly smaller diameter than the straight tube 41. As shown in FIG. 3B, the torsion tube 42 is subjected to a torsion process (a torsion portion 42c) on its peripheral surface. The torsion tube 42 includes a connection pipe 33 (see FIG. 2) connected to the compressor 22 and a connection pipe 34 (see FIG. 2) connected to the condenser 23.
And the discharge port 42b. Also,
The outermost peripheral portion of the outer peripheral surface of the torsion tube 42 (the maximum diameter portion including the convex portion of the torsion portion 42c, the outer peripheral surface of the inlet 42a, and the outer peripheral surface of the outlet 42b) are equal to the inner diameter of the straight pipe 41. The diameter is specified. Therefore, as shown in FIG. 4, when the torsion tube 42 is inserted into the straight tube 41, the outermost peripheral portion of the outer surface of the torsion tube 42 is
1 and is connected to the inner surface thereof. In this case, since the torsion portion 42c is formed in a spiral shape, the torsion tube 42c is formed.
Is formed with a spiral groove S1 on the outer surface thereof. Therefore, between the inner peripheral surface of the straight pipe 41 and the outer peripheral surface of the torsion pipe 42, a spiral flow path through which the low-temperature and low-pressure refrigerant discharged from the evaporator 21 passes is formed by the spiral groove S <b> 1. You. The refrigerant reheat pipe 26 is disposed such that the end on the inlet 41a side is located above the outlet 41b. Therefore, the hydraulic oil contained in the refrigerant is supplied to the inlet 4
The refrigerant flows down the outer periphery of the torsion tube 42 together with the refrigerant from 1a, and is smoothly discharged from the discharge port 41b.

Next, the operating principle of the dehumidifier 1 will be specifically described with reference to the drawings.

In the dehumidifier 1, the compressor 22 sucks the vaporized refrigerant in the evaporator 21 through a path indicated by an arrow A1 in FIG. 1, compresses the absorbed vaporized refrigerant, and condenses the refrigerant through a path indicated by an arrow A2. To the vessel 23 sequentially. At this time, the high-temperature and high-pressure vaporized refrigerant discharged from the compressor 22 is pressure-fed to the refrigerant reheat pipe 26 via the connection pipe 33, and is fed into the torsion pipe 42 through the introduction port 42a in the direction of arrow B1 in FIG. And passes through the torsion pipe 42 and is discharged to the connecting pipe 34 through the discharge port 42b in the direction of arrow B2. In this case, the torsion tube 4
2 is twisted on the peripheral surface of the torsion tube 4
The refrigerant passing through the pipe 2 is twisted by the twisting process.
5 along a groove S2 (recess on the inner peripheral surface of the torsion tube 42) formed on the inner peripheral surface of the torsion tube 42 so as to draw a gentle spiral trajectory as indicated by an arrow B in FIG. Therefore, the passage time of the refrigerant from the inlet 42a to the outlet 42b is longer than when the refrigerant passes straight through the straight pipe.

On the other hand, the vaporized refrigerant discharged to the connecting pipe 34 is liquefied by the condenser 23 and stored in the receiver 24. Next, the liquefied refrigerant in the receiver 24 is supplied to the expansion valve 2.
The secondary cooling unit 12 is discharged into the evaporator 21 through the outlet 5 and expands and vaporizes in the evaporator 21 to cool the secondary cooling unit 12. Next, when an air compressor (not shown) is driven, high-humidity compressed air is introduced into the heat exchanger 2 through the inlet 2a, and is dehumidified and reheated in the same manner as the dehumidifier 51. After that, it is discharged to the outside of the heat exchanger 2 through the discharge port 2b.

The vaporized refrigerant vaporized in the evaporator 21 is transferred to the compressor 22 by connecting the connecting pipe 31, the refrigerant reheating pipe 26, the connecting pipe 32a, the accumulator 27 and the connecting pipe 32b as shown by an arrow A1 in FIG. Move toward. At this time,
As shown in FIG. 4, the refrigerant reheat pipe 26
Is introduced into the straight pipe 41 through the inlet 41a in the direction of the arrow C1.
Through the groove S1 between the discharge ports 4 in the direction of the arrow C2.
It is discharged to the connecting pipe 32b via 1b. In this case, in the refrigerant reheat pipe 26, the refrigerant passing through the spiral groove S1 passes in a spiral path as shown by an arrow C in FIG. Therefore, the passage time of the refrigerant from the inlet 41a to the outlet 41b is longer than when the refrigerant passes linearly. That is, the residence time of the refrigerant in the straight pipe 41 becomes longer. In addition, since the residence time of the refrigerant in the torsion tube 42 is long, a high-temperature and high-pressure vaporized refrigerant discharged from the compressor 22 and passing through the torsion tube 42 is provided.
Straight pipe 41 and torsion pipe 42 discharged from evaporator 21
The low-temperature refrigerant passing through the groove S1 between the torsion tube 4
Heat is sufficiently exchanged through the second wall. Further, when the return refrigerant discharged by the secondary cooling unit 12 contains a large amount of liquefied refrigerant, the amount of heat exchange increases due to latent heat of vaporization,
In addition, when the amount of the vaporized refrigerant is large, the evaporation pressure and the heating degree are properly maintained by the self-regulating action of reducing the heat exchange amount.

On the other hand, when the flow rate of the compressed air introduced into the heat exchanger 2 is small, for example, when the load is low, the amount of the refrigerant vaporized in the evaporator 21 is reduced, so that the vaporized refrigerant and the liquefied refrigerant are reduced. Are discharged from the evaporator 21 in a state in which is mixed. At this time, in the dehumidifier 1, when the liquefied refrigerant passes through the refrigerant reheat pipe 26, the liquefied refrigerant exchanges heat with the high-temperature vaporized refrigerant in the torsion pipe 42 and evaporates. As a result, only the vaporized refrigerant evaporated in the refrigerant reheat pipe 26 is discharged from the refrigerant reheat pipe 26 without discharging the liquefied refrigerant. When a very small amount of the liquefied refrigerant is discharged from the refrigerant reheat pipe 26, the vaporized refrigerant and the liquefied refrigerant are separated by the accumulator 27. Therefore, in the refrigerating mechanism 3, the accumulator 27 is miniaturized because it is sufficient to store a very small amount of the liquefied refrigerant.

When the pressure becomes lower than the predetermined pressure range in the refrigeration mechanism 3, the control valve 28 is opened, so that the high-temperature and high-pressure vaporized refrigerant discharged from the compressor 22 is discharged. A part of the connecting pipe 3 is indicated by an arrow A3.
5 to the connecting pipe 31. Therefore, the suction pressure of the refrigerant is adjusted to a predetermined suction pressure. In this case, in the refrigeration mechanism 3, the liquefied refrigerant discharged from the evaporator 21 evaporates in the refrigerant reheat pipe 26, so that the suction pressure increases. Therefore, as compared with the conventional refrigeration mechanism 53, the suction pressure is adjusted to the specified pressure only by opening the control valve 28 for a shorter time. Therefore, when the load is low, the dehumidifying efficiency can be improved, and the operation amount of the compressor 22 can be reduced to reduce the circulation amount of the refrigerant. As a result, the power consumption of the compressor 22 can be reduced. .

On the other hand, when the pressure of the vaporized refrigerant discharged from the compressor 22 exceeds the specified pressure, the control unit 4 rotates the cooling fan FN according to the sensor signal of the sensor PS. Therefore, the liquefaction of the vaporized refrigerant in the condenser 23 is promoted, and as a result, the pressure of the vaporized refrigerant discharged from the compressor 22 decreases to the specified pressure.

As described above, in the dehumidifier 1 (refrigeration mechanism 3), the low-temperature refrigerant (liquefied refrigerant) discharged from the evaporator 21 and the high-temperature refrigerant (vaporized refrigerant) discharged from the compressor 22 are combined. Since the liquefied refrigerant rises in temperature and evaporates in the refrigerant reheat pipe 26 before reaching the accumulator 27 by performing heat exchange in the refrigerant reheat pipe 26, the liquefied refrigerant stored in the accumulator 27 can be significantly reduced. it can. Therefore, the damage of the compressor 22 can be sufficiently prevented only by providing the relatively low-priced small accumulator 27, so that the manufacturing cost of the refrigeration mechanism 3 and the manufacturing cost of the dehumidifier 1 can be reduced. Further, the refrigerant reheat pipe 26 is configured by a double pipe structure of the straight pipe 41 and the torsion pipe 42, and the torsion processing is performed on the torsion pipe 42 to supply the refrigerant to the groove S1 between the straight pipe 41 and the torsion pipe 42. By allowing the refrigerant to pass through, it is possible to cause sufficient heat exchange between the refrigerant passing through the straight pipe 41 and the refrigerant passing through the torsion pipe 42. Further, since the torsion tube 42 is housed in the straight tube 41 to constitute the refrigerant reheating tube 26, the torsion tube 4
As compared with the configuration in which the straight pipe 41 is accommodated in the pipe 2, it is possible to prevent dust from sticking to the outer peripheral surface of the refrigerant reheating pipe. Further, for example, when the load is low, the amount of the circulating refrigerant can be reduced, so that the power consumption of the compressor 22 can be reduced.

The present invention is not limited to the configuration shown in the above embodiment of the present invention. For example, in the embodiment of the present invention, the example in which the outermost peripheral portion of the torsion pipe 42 is connected to the inner peripheral surface of the straight pipe 41 to form the refrigerant reheat pipe 26 has been described. The configuration is not limited to this. For example, as in a refrigerant reheating tube 26A shown in FIG. 6, the inner peripheral surface of the straight tube 41 and the outermost peripheral portion of the torsion tube 42 may be separated. Even with this configuration, the inlet 41a
Is introduced into the groove S1 formed on the outer peripheral surface of the torsion tube 42 and passes through the refrigerant reheating tube 26 in a spiral trajectory, so that the refrigerants can sufficiently exchange heat with each other. Can be. Further, as in a refrigerant reheat pipe 26B shown in FIG. 7, a straight pipe 41 may be housed in a torsion pipe 42 to form a double pipe structure. Further, the twisted pipe 4
The straight pipe is housed in the straight pipe 41 in place of 2 and a spiral linear member is inserted between the outer peripheral surface of the straight pipe and the inner peripheral surface of the straight pipe 41, so that the distance between the linear members is reduced. A groove may be formed in the groove.

[0025]

As described above, according to the refrigerating apparatus of the first aspect, the refrigerant reheating means is constituted by the inner pipe and the outer pipe in a double pipe structure, and the outer peripheral surface of the inner pipe or the outer pipe is formed. By forming the spiral groove on the inner peripheral surface, the refrigerant passing between the inner pipe and the outer pipe passes in a spiral trajectory, so that sufficient heat exchange between the two refrigerants is possible. it can. Therefore, since the liquefied refrigerant can be reliably evaporated, the accumulator for avoiding the inflow of the liquefied refrigerant into the compressor can be downsized. As a result, the compressor can be reliably prevented from being damaged while reducing the manufacturing cost and power consumption of the refrigeration apparatus.

According to the refrigeration apparatus of the second aspect,
By contacting and connecting the outermost portion on the outer peripheral surface of the inner tube and the innermost portion on the inner peripheral surface of the outer tube to form a spiral flow path in the refrigerant reheating means, the inner tube and the outer tube Since it is possible to reliably pass the refrigerant passing between them so as to draw a spiral trajectory, it is possible to lengthen the passage time of the refrigerant passing through the spiral flow path, thereby evaporating the liquefied refrigerant more reliably. be able to.

Further, according to the refrigeration apparatus of the third aspect, the inner pipe is formed of a torsion pipe and the outer pipe is formed of a straight pipe, compared with a configuration in which a straight pipe is inserted into a torsion pipe. Further, it is possible to prevent dust from sticking to the outer surface of the refrigerant reheating tube means.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a configuration of a dehumidifying device 1 according to an embodiment of the present invention.

FIG. 2 is an external view of a refrigerant reheat pipe 26 according to the embodiment of the present invention.

3A is a cross-sectional view of a straight pipe 41 in a refrigerant reheating pipe 26, and FIG. 3B is a cross-sectional view of a torsion pipe 42.

FIG. 4 is a cross-sectional view of the refrigerant reheat pipe 26.

FIG. 5 is a schematic diagram showing a flow of a refrigerant passing through a refrigerant reheat pipe 26.

FIG. 6 shows a refrigerant reheat pipe 26 according to another embodiment of the present invention.
It is sectional drawing of A.

FIG. 7 is an external view of a refrigerant reheat pipe 26B according to still another embodiment of the present invention.

FIG. 8 is a configuration diagram showing a configuration of a conventional dehumidifier 51.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Dehumidifier 2 Heat exchanger 3 Refrigeration mechanism 21 Evaporator 22 Compressor 26, 26A, 26B Refrigerant pipe 27 Accumulator 28 Control valve 41 Straight pipe 42 Twist pipe 42c Twist processing part S1, S2 Groove part

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3L103 AA05 AA35 AA39 BB33 CC01 CC18 CC21 CC30 DD03 DD10 DD38

Claims (3)

[Claims] 1. a low-temperature refrigerant discharged by an evaporator;
A refrigeration apparatus including a refrigerant reheating unit that exchanges heat with a high-temperature refrigerant that is compressed by a compressor and pumped toward a condenser, wherein the refrigerant reheating unit is configured such that one of the two refrigerants is used. An inner pipe that passes therethrough, and an outer pipe through which either of the two refrigerants passes while the inner pipe is inserted and the inner pipe is formed in a double pipe structure, and an outer peripheral surface of the inner pipe Alternatively, a refrigeration apparatus characterized in that a spiral groove is formed on the inner peripheral surface of the outer tube. 2. The coolant reheating means is configured such that the outermost peripheral portion of the outer peripheral surface of the inner tube and the innermost peripheral portion of the inner peripheral surface of the outer tube are brought into contact with each other and connected to each other, thereby forming a spiral in the groove. The refrigeration apparatus according to claim 1, wherein a flow path is formed. 3. The refrigeration apparatus according to claim 1, wherein the refrigerant reheating means has the inner pipe formed of a torsion pipe and the outer pipe formed of a straight pipe.