JP2000205134A - Air compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air compressor capable of reducing the power consumption. SOLUTION: A first heat-exchanger 5 for evaporation of a refrigerant to form a first circulating path 14 for refrigerant of a refrigerating device together with the body 11 of compressor for refrigerant, a second heat-exchanger 12 for condesation of refrigerant, and an expansion valve 13 is interposed as a suction air cooling means in a suction passage 2 to lead the air taken in from the atmosphere through an air filter 4 to the suction port in the compressor body 1 so that heat exchange is made between the refrigerant and suction air.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air compressor for sucking and compressing atmospheric air.

[0002]

2. Description of the Related Art Conventionally, air compressors have been widely used in various fields. And basically, this air compressor takes in air in the atmosphere via an air filter into a suction flow path connected to a suction port of the compressor body, and compresses the air with the compressor body. It is formed so as to discharge from a discharge port of the compressor body.

[0003]

In the case of the above-mentioned conventional air compressor, when the temperature of the air sucked from the suction port, that is, the suction temperature increases, the density of the suction air decreases. For this reason, there is a problem that the amount of air discharged from the compressor body per unit power decreases correspondingly, and power consumption increases. SUMMARY OF THE INVENTION The present invention has been made to solve such a conventional problem, and has as its object to provide an air compressor capable of reducing power consumption.

[0004]

In order to solve the above-mentioned problems, a first aspect of the present invention is directed to a configuration in which intake cooling means is provided in a suction passage for guiding air taken from the atmosphere to a suction port of a main body of an air compressor. And

According to a second aspect of the present invention, the intake cooling means includes:
A first heat exchanger for refrigerant evaporation forming a first circulation path for refrigerant of a refrigeration system together with a refrigerant compressor body, a second heat exchanger for refrigerant condensation, and an expansion valve, wherein the first heat exchanger In this configuration, heat exchange is performed between the refrigerant and the suction air.

Further, according to a third aspect of the present invention, the discharge passage of the air compressor main body includes an aftercooler, a reheater, a third heat exchanger, and a drain trap. The refrigerant compressor body, the fourth heat exchanger for condensing the refrigerant, the expansion valve, and the fifth heat exchanger for evaporating the refrigerant form a second circulation path for the refrigerant, functioning for refrigerant evaporation, and But,
In the fifth heat exchanger, after the compressed air discharged from the air compressor body passes through the reheater, the third heat exchanger, and the drain trap in the order of an aftercooler, The compressed air discharged through the reheater again is sent out of the machine, and the discharged compressed air is first cooled by an aftercooler, and the reheater exchanges heat with the compressed air that has passed through the drain trap. The temperature of the compressed air is increased, and the compressed air is cooled by the third heat exchanger. The deposited water is removed by the drain trap. The dried air is brought into a dry state. It was configured to be replaced.

In a fourth aspect of the present invention, the discharge passage of the air compressor body includes an aftercooler, a reheater, and a sixth evaporator.
A sixth heat exchanger having a heat exchanger and a drain trap, wherein the sixth heat exchanger includes a refrigerant compressor body, a refrigerant heat condensing seventh heat exchanger, an expansion valve, and a first flow control valve, and a third circulation path for refrigerant. The refrigerant compressor body and the seventh heat exchanger together with the second flow rate control valve and the eighth heat exchanger for refrigerant evaporation form a fourth refrigerant circulation path. The intake cooling means is the eighth heat exchanger, and the compressed air discharged from the air compressor body is supplied from an aftercooler to the reheater, the sixth heat exchanger, the drain trap. After passing through these in the order of above, it is again sent out of the machine through the reheater, and the discharged compressed air is first cooled by an aftercooler and passed through the drain trap by the reheater. By exchanging heat with the compressed air to raise the temperature of the compressed air, While being cooled in exchanger, it removed the precipitated water in the drain trap, a dry state,
The eighth heat exchanger is configured to perform heat exchange between the refrigerant and the intake air.

[0008]

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows an air compressor according to a first embodiment of the present invention, in which a suction channel 2 is connected to a suction port of a compressor body 1 for air, and a discharge channel 3 is connected to a discharge port.
The suction passage 2 is provided with an air filter 4, a first heat exchanger 5 serving as intake air cooling means, and a drain trap 6. Then, the air in the atmosphere is taken into the suction passage 2 through the air filter 4, cooled in the first heat exchanger 5 as described later, and the drain deposited here is separated and discharged by the drain trap 6. , The cooled air is compressed by the compressor body 1,
The liquid is discharged from the discharge port to the discharge channel 3.

The first heat exchanger 5 forms a part of the air compressor and also forms a part of a refrigeration system.
This refrigeration system includes a refrigerant first circulation path 14 including a refrigerant compressor main body 11, a water-cooled second heat exchanger 12 for refrigerant condensation, an expansion valve 13, and a first heat exchanger 5 for refrigerant evaporation. Has formed. The refrigerant compressed by the refrigerant compressor body 11 is deprived of heat by heat exchange with the cooling water in the second heat exchanger 12 and condensed to become a high-pressure refrigerant liquid.
Inflated at 3. Further, the refrigerant liquid exchanges heat with the air introduced into the suction passage 2 via the air filter 4 in the first heat exchanger 5 to evaporate, and the vaporization heat at that time causes the refrigerant liquid in the suction passage 2 to evaporate. Cool the air.

As described above, in this air compressor, the air sucked into the compressor body 1 is cooled to lower the suction temperature, so that the air density increases,
The discharge air volume per unit power increases. For example, when the suction temperature is set to 10 ° C. by cooling by the first heat exchanger 5 when the ambient temperature is 30 ° C., the discharge air volume increases by 7% as compared with the case where the cooling is not performed. When the compressor body 1 is of an oil-cooled type that injects lubricating oil into a rotor chamber that performs air compression, when the suction temperature decreases, the temperature of the compressed air discharged from the compressor body 1, that is, the discharge temperature As a result, the viscosity of the lubricating oil is increased, and as a result, the sealing performance of the rotor chamber is improved, the efficiency of air compression of the compressor body 1 is improved, and the discharge air volume is further increased.

Further, when the compressor body 1 is of an oil-cooled type in which lubricating oil is injected into the rotor chamber, the suction temperature decreases, and when the discharge temperature decreases, the lubricating oil temperature also decreases.
As a result of lowering the lubricating temperature to the rotor chamber, the problem that the sucked air is warmed and thermally expanded and the density is reduced, that is, the problem of suction heating is solved to some extent, whereby the air density increases and the discharge increases. The air volume is further increased. Since the discharge air volume is increased by more than 10% compared to our conventional machine, the total power consumption is about 10% even in consideration of the fact that the power consumption by the first heat exchanger 5 is increased by several%. Power can be saved. Further, when the discharge temperature decreases, the aftercooler conventionally provided in the discharge passage 3 of the compressor body 1 is reduced in size,
Or it can be omitted.

FIG. 2 shows an air compressor according to a second embodiment of the present invention. Portions common to the air compressor according to the first embodiment are denoted by the same reference numerals, and description thereof is omitted. I do. In this air compressor, the air compressor body 1
Air-cooled aftercooler 21 and reheater 2
2, the third heat exchanger 23 and the drain trap 6,
The third heat exchanger 23 includes a refrigerant compressor body 11, a water-cooled fourth heat exchanger 24 for condensing refrigerant, an expansion valve 13, and a fifth heat exchanger 25 for evaporating refrigerant. 2
A circulation path 26 is formed. The portion surrounded by the dashed line A in FIG. 2 functions as a dryer for drying the compressed air, while the fifth heat exchanger 25 is also an intake air cooling unit in the suction passage 2. In addition, the * mark in FIG. 2 means that they are continuous.

Specifically, as in the case of the first embodiment, the refrigerant liquid passing through the expansion valve 13 is supplied to the fifth heat exchanger 25.
The heat exchanges with the air in the suction passage 2 to partially evaporate and cool the air. The compressed air discharged from the compressor body 1 is first cooled by the aftercooler 21 and exchanges heat with the compressed air passing through the drain trap 6 of the discharge passage 3 by the reheater 22. The temperature of the compressed air is raised, and
It reaches the heat exchanger 23. In the third heat exchanger 23, the refrigerant evaporates and the compressed air is cooled by heat exchange between the compressed air and the partially evaporated refrigerant,
The deposited water is separated and discharged by the drain trap 6, and the compressed air is in a dry state.
The temperature rises, and the air is dried and sent out of the machine.

With this configuration, the suction temperature is reduced, the discharge air volume is increased, the power consumption is reduced, and the size of the aftercooler 21 can be reduced, as in the first embodiment. It has become. Although the aftercooler 21 is provided in FIG. 2, the aftercooler 21 can be omitted by providing the fifth heat exchanger 26. Further, by cooling the intake air and removing the drain deposited in the suction passage, the drying operation in the discharge passage can be omitted or the operation time can be shortened.

FIG. 3 shows an air compressor according to a third embodiment of the present invention. Portions common to the air compressors according to the above-described embodiments are denoted by the same reference numerals, and description thereof is omitted. . In this air compressor, an air-cooled aftercooler 21 and a reheater 22 are provided in the discharge passage 3 of the air compressor body 1.
, A sixth heat exchanger 31 and a drain trap 6. On the other hand, on the secondary side of the expansion valve 13, the refrigerant flow path is divided into two parts, one of which is a refrigerant compressor body 11, a water-cooled fourth heat exchanger 24 for refrigerant condensation, an expansion valve 13, A part of the third circulation path 33 for the refrigerant of the refrigeration apparatus including the one flow control valve 32 and the sixth heat exchanger 31 for evaporating the refrigerant is formed.
A portion surrounded by a chain line B in FIG. 3 functions as a dryer for drying the compressed air.

The other of the two divided refrigerant flow paths includes a refrigerant compressor body 11, a water-cooled fourth heat exchanger 24 for condensing refrigerant, an expansion valve 13, a second flow control valve 34, and the like. A part of the fourth circulation path for refrigerant 36 of the refrigeration apparatus including the seventh heat exchanger 35 for refrigerant evaporation is formed. In addition, this seventh
The heat exchanger 35 is also an intake air cooling unit in the intake passage 2. Note that, as in the above, the * marks in FIG. 3 mean that they are continuous. In the device according to the third embodiment, the first flow control valve 32 and the second flow control valve 34
By adjusting the respective opening degrees of the third circulation path 33
The amount of the refrigerant flowing through the fourth circulation path 36 is changed, so that the respective functions of the intake air cooling and the dryer can be adjusted. Instead of the first flow control valve 32 and the second flow control valve 34, a three-way switching valve is provided at a branch portion of the refrigerant flow path on the secondary side of the expansion valve 13 to adjust the amount of refrigerant guided to each circulation path. You may make it. In addition, as described above, with such a configuration, the suction temperature is reduced, the discharge air volume is increased, the power consumption is reduced, and the aftercooler 21 can be downsized. Although the aftercooler 21 is provided in FIG. 2, the aftercooler 21 is provided by providing the seventh heat exchanger 35.
May be omitted.

In each of the above-mentioned embodiments, the heat of vaporization of the refrigerant in the refrigerating apparatus is used for cooling the intake air. However, the present invention is not limited to this. Fifth heat exchanger 25 and seventh heat exchanger 35
In place of this, a compressor provided with an air-cooled or water-cooled heat exchanger is also included. In addition, the water-cooled fourth heat exchanger 24
, An air-cooled heat exchanger may be provided, and a water-cooled aftercooler may be provided in place of the air-cooled aftercooler 21, all of which are included in the present invention. Further, the compressor body in the present invention may be any of an oil-free type and an oil-cooled type. When the compressor body is an oil-cooled type, as is well known, the discharge side of the compressor body is And an oil supply passage extending from the lower portion through an oil cooler and an oil filter to a lubrication point in the compressor body.

[0018]

As is apparent from the above description, according to the present invention, since the intake air of the compressor is cooled, the suction temperature is reduced, the discharge air volume is increased, and the power consumption is reduced. Therefore, the aftercooler which is usually provided can be reduced in size or omitted. In addition, by using the refrigerant of the dryer, which is an auxiliary device in the discharge flow path, for cooling the intake air, the structure can be simplified as compared with the case where a new cooling medium is used for cooling the intake air, and the cooling on the intake cooling side can be performed. By adjusting the amount of the refrigerant flowing to each of the dryers, it is possible to achieve an effect that the suction temperature can be adjusted to an optimum suction temperature in accordance with the outside air temperature.

[Brief description of the drawings]

FIG. 1 is a diagram showing an overall configuration of an air compressor according to a first embodiment of the present invention.

FIG. 2 is a diagram illustrating an overall configuration of an air compressor according to a second embodiment of the present invention.

FIG. 3 is a diagram illustrating an entire configuration of an air compressor according to a third embodiment of the present invention.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 air compressor main body 2 suction flow path 3 discharge flow path 4 air filter 5 first heat exchanger 6 drain trap 11 refrigerant compressor main body 12 second heat exchanger 13 expansion valve 14 refrigerant first circulation path 21 after Cooler 22 Reheater 23 Third heat exchanger 24 Fourth heat exchanger 25 Fifth heat exchanger 26 Second circulation path for refrigerant 31 Sixth heat exchanger 32 First flow control valve 33 Third circulation path 34 Second Flow control valve 35 Seventh heat exchanger 36 Fourth circulation path for refrigerant

Claims (4)

[Claims] 1. An air compressor characterized in that an intake cooling means is provided in a suction flow passage for guiding air taken in from the atmosphere to a suction port of a compressor body for air. 2. A first heat exchange for evaporating a refrigerant which forms a first circulation path for a refrigerant of a refrigerating apparatus together with a compressor body for a refrigerant, a second heat exchanger for condensing the refrigerant, and an expansion valve. 2. The air compressor according to claim 1, wherein heat is exchanged between the refrigerant and the intake air in the first heat exchanger. 3. 3. A discharge channel of the air compressor main body has an aftercooler, a reheater, a third heat exchanger, and a drain trap, and the third heat exchanger is a refrigerant compressor main body. And a fourth heat exchanger for condensing the refrigerant, an expansion valve, and a fifth heat exchanger for evaporating the refrigerant to form a second circulation path for the refrigerant, and work for evaporating the refrigerant. In the heat exchanger, the compressed air discharged from the air compressor main body passes through the after-cooler in the order of the reheater, the third heat exchanger, and the drain trap, and then again. The compressed air discharged through the reheater is sent out of the machine.The discharged compressed air is first cooled by an aftercooler, and the reheater exchanges heat with the compressed air that has passed through the drain trap. And the third
The method is characterized in that cooling is performed by a heat exchanger, and precipitated water is removed by the drain trap, and a dry state is obtained. On the other hand, the fifth heat exchanger performs heat exchange between refrigerant and suction air. Item 7. The air compressor according to Item 1. 4. A discharge passage of the air compressor main body includes an aftercooler, a reheater, a sixth heat exchanger for evaporation, and a drain trap, wherein the sixth heat exchanger includes a refrigerant compressor. Forming a third circulation path for the refrigerant together with the main body, the fourth heat exchanger for condensing the refrigerant, the expansion valve, and the first flow control valve, and working for evaporating the refrigerant; A fourth circulation path for the refrigerant together with the second flow control valve and the seventh heat exchanger for evaporating the refrigerant, wherein the intake cooling means is the seventh heat exchanger, Compressed air discharged from the compressor body passes through the aftercooler in the order of the reheater, the sixth heat exchanger, and the drain trap, and then passes through the reheater again and is sent out of the machine. The compressed air discharged is first cooled by an aftercooler, Replace heat and compressed air passing through the drain trap, allowed to warm to the compressed air, the sixth
The method is characterized in that cooling is performed by a heat exchanger, and precipitated water is removed by the drain trap, and a dry state is obtained. On the other hand, the seventh heat exchanger causes heat exchange between refrigerant and suction air. Item 7. The air compressor according to Item 1.