JP2022041737A - Compressed-gas cooling method of compressor and compressed-gas cooling device - Google Patents

Abstract

To properly cool a compressed gas by low-consumption power while preventing overcooling.SOLUTION: A heat exchanger 51 and a cooling fan 52 for introducing a cooling wind to the heat exchanger are arranged at a supply flow passage 40 of a capacity-control type compressor 1. An upper limit value TH and a lower limit value TL in corresponding temperature areas TL to TH which are decided on the basis of pressure Pd in the supply flow passage 40 of a check valve 41 at a secondary side, and a temperature Td in the supply flow passage 40 of the heat exchanger 51 at a primary side are compared. When the temperature Td is lower than the lower limit value TL, the cooling fan 52 is operated at a prescribed lowest rotational speed FL, also, when the temperature Td exceeds the upper limit value TH, the cooling fan 52 is operated at a prescribed highest rotational speed FH, and when the temperature Td is within the corresponding temperature regions TL to TH, the rotational speed of the cooling fan 52 is ascended and descended following a preset correspondence relationship, and following a rise and a fall of the temperature Td in the supply flow passage 40 between the lowest rotational speed FL and the highest rotational speed FH.SELECTED DRAWING: Figure 1

Description

The present invention relates to a method for cooling a compressed gas generated by a compressor body of a compressor and a compressed gas cooling device for executing the cooling method. More specifically, the present invention applies cooling air to a heat exchanger for cooling the compressed gas. The present invention relates to a method for cooling compressed gas in a compressor and a compressed gas cooling device, which are characterized by controlling the rotation speed of the cooling fan to be introduced.

In a compressor that compresses the compressed gas with the compressor body to generate the compressed gas, the generated compressed gas has a high temperature due to the heat of compression, and if such a high temperature compressed gas is supplied to the consumption side as it is, it will be consumed. Coagulated water is generated by cooling the compressed gas in the piping system on the side.

Therefore, the compressed gas discharged from the compressor body is introduced into a heat exchanger (aftercooler) provided in the supply flow path connecting the discharge port of the compressor body and the consumption side to be cooled before being supplied to the consumption side. , The dry compressed gas obtained by removing the agglomerated water generated during cooling by this aftercooler is introduced to the consumption side.

In a compressor equipped with such an aftercooler, a motor-driven cooling fan is provided in order to efficiently exchange heat, and a configuration is adopted in which the cooling air generated by the cooling fan is constantly introduced into the aftercooler. ..

The introduction of the cooling air to the aftercooler is generally performed by operating the cooling fan at a constant rotation speed, and the control for changing the rotation speed of the cooling fan is not performed.

On the other hand, as shown in FIG. 12, the pressure detecting means 155 that detects the pressure of the compressed gas supplied to the consuming side detects it for the purpose of reducing the power consumption of the entire compressor including the power consumption of the cooling fan. When the pressure of the compressed gas supplied to the consumption side reaches the predetermined no-load operation start pressure based on the pressure, the control device 154 operates the intake control valve 131 to operate the suction port of the compressor main body 110 (in the example shown in the figure). The suction port of the low-pressure stage compressor 111) is closed to shift to no-load operation, and the cooling fan 152 that introduces cooling air into the aftercooler 151 is operated at a predetermined low rotation speed, and the compressed gas supplied to the consumption side is operated. When the pressure of the gas reaches a predetermined full load operation return pressure, the suction port of the compressor main body 110 closed by the intake control valve 131 is opened to start the full load operation, and the cooling fan 152 is operated at a predetermined high rotation speed. A compressor 100 is also proposed (claim 1, FIG. 3 of Patent Document 1).

Although the prior technology for cooling the compressed gas is not disclosed, the pressure of the compressed gas supplied to the consumer side by controlling the rotation speed of the motor that drives the compressor body with an inverter. There is also one in which the setting of (target pressure) can be changed (Patent Document 2).

Japanese Unexamined Patent Publication No. 2008-128052 Japanese Unexamined Patent Publication No. 2008-151076

In the compressor 100 described in Patent Document 1 described above, the power consumption of the cooling fan during the no-load operation is reduced by operating the cooling fan 152 at a predetermined low rotation speed during the no-load operation of the compressor main body 110. be able to.

However, in the configuration described in Patent Document 1 described above, only by switching the rotation speed of the cooling fan 152 between load operation and no-load operation, the rotation speed of the cooling fan 152 can be changed to the temperature of the compressed gas to be cooled. It cannot be changed according to the flow rate and pressure.

Therefore, when the outside temperature is low and the compressed gas temperature is relatively low, or when the consumption of the compressed gas on the consumption side is small and therefore the flow rate of the compressed gas passing through the aftercooler 151 is small, the aftercooler 151 Since the cooling fan 152 is operated at a predetermined high rotation speed even if the compressed gas supplied to the consumption side can be appropriately cooled even if the amount of cooling air introduced to the cooling fan 152 is reduced, the cooling fan 152 is operated. Surplus power is still consumed in the operation of the gas, and there is still room for power saving.

Further, as described above, when the outside temperature is low and therefore the compressed gas temperature is relatively low, or when the consumption of the compressed gas on the consumption side is small and the flow rate of the compressed gas passing through the aftercooler 151 is small. However, when the compressor body 110 is in load operation, the cooling fan 152 is rotated at a high rotation speed to introduce a large amount of cooling air into the aftercooler 151, so that the compressed gas is excessive in the aftercooler 151. It becomes "supercooling" to be cooled, and depending on the usage environment of the compressor 100 such as use in cold regions, the aggregated water freezes in the aftercooler 151, and the temperature difference between the inlet side and the outlet side of the aftercooler 151 is excessive. This can cause problems such as damage to the aftercooler 151 due to thermal strain, a so-called "heat shock" phenomenon, and the like.

Therefore, it is necessary to have a cooling method and cooling device that appropriately cools the compressed gas while preventing the occurrence of such "supercooling" in consideration of the temperature, pressure, flow rate, etc. of the compressed gas to be cooled. Become.

Further, as in Patent Document 2 mentioned above, the compressor can change the pressure (target pressure) of the compressed gas supplied to the consumer side by controlling the rotation speed of the motor that drives the compressor body with an inverter. In such a compressor, it is more important to control the amount of air blown in consideration of the pressure of the compressed gas in order to properly cool the compressed gas.

Therefore, the present invention has been made to eliminate the above-mentioned drawbacks in the prior art, and is used for a heat exchanger such as an aftercooler that cools the compressed gas generated by the compressor body before introducing it to the consumption side. By appropriately controlling the rotation speed of the cooling fan (the amount of cooling air introduced into the heat exchanger), the power consumption can be further reduced and the noise such as wind noise generated by the cooling fan can be reduced. Not only can it be achieved, but it is also possible to prevent the occurrence of overcooling, prevent damage to the heat exchanger due to freezing of aggregated water and heat shock, and cool the compressed gas appropriately according to the pressure change of the compressed gas. It is an object of the present invention to provide a compressed gas cooling method and a compressed gas cooling device in a compressor capable of capable of cooling.

The means for solving the problem are described below together with the reference numerals used in the embodiment for carrying out the invention. This reference numeral is for clarifying the correspondence between the description of the scope of claims and the description of the form for carrying out the invention, and needless to say, it is used in a limited manner in the interpretation of the technical scope of the present invention. It is not something that can be done.

In order to achieve the above object, the method for cooling the compressed gas in the compressor 1 of the present invention is as follows.
The compressor main body 10 that generates compressed gas, an intake control valve 31 that controls opening and closing of the intake port of the compressor main body 10, a supply flow path 40 from the discharge port of the compressor main body 10 to the consumption side, and the supply. Capacity control is provided with a check valve 41 provided in the flow path 40, and the pressure Pd of the compressed gas supplied to the consumption side is controlled to approach a predetermined target pressure by controlling the intake amount by the intake control valve 31. In the type compressor 1,
A heat exchanger (aftercooler) 51 for cooling the compressed gas passing through the supply flow path 40 and a cooling fan 52 for introducing cooling air into the heat exchanger 51 are provided.
The lower limit TL and upper limit TH of the predetermined corresponding temperature range TL-TH determined based on the pressure Pd in the supply flow path 40 on the secondary side of the check valve 41, and the primary of the heat exchanger 51. Compare with the temperature Td in the supply flow path 40 on the side and on the primary side of the check valve 41.
When the temperature Td in the supply flow path 40 is less than the lower limit value TL of the corresponding temperature range TL-TH, the cooling fan 52 is operated at a predetermined minimum rotation speed FL.
When the temperature Td in the supply flow path 40 exceeds the upper limit value TH of the corresponding temperature range TL-TH, the cooling fan 52 is operated at a predetermined maximum rotation speed FH.
When the temperature Td in the supply flow path 40 is within the range of the corresponding temperature range TL-TH, according to the correspondence relationship between the temperature Td in the supply flow path 40 and the rotation speed F of the cooling fan 52 set in advance. The rotation speed of the cooling fan 52 is increased according to the increase in the temperature Td in the supply flow path 40 between the minimum rotation speed FL and the maximum rotation speed FH, and the temperature Td in the supply flow path 40 is decreased. It is characterized in that the rotation speed of the cooling fan 52 is lowered (claim 1).

It is preferable to determine the corresponding temperature range TL-TH so that the lower limit value TL and the upper limit value TH increase with respect to the increase in the pressure Pd in the supply flow path 40 (claim 2).

The range of pressure that can be taken by the pressure Pd in the supply flow path 40 is divided into predetermined numerical ranges (Pd ≦ 0.4 MPa and 0.4 MPa <Pd in Example 2), and each divided numerical range is divided. The increase rates IRL and IRH of the lower limit value TL and the upper limit value TH are different values (IRL = IRH = 50 when Pd ≦ 0.4 MPa and IRL = IRH = 100 when 0.4 MPa <Pd in Example 2). ) May be set (see claim 3 and FIG. 6).

In at least a part of the pressure range that the pressure Pd in the supply flow path 40 can take (the range of Pd ≦ 0.4 MPa in Example 3), the increase rate IRL of the lower limit value TL and the upper limit value TH. The rate of increase IRH may be set to a different value (IRL = 50, IRH = 75 in Example 3) (see claims 4 and 8).

The lower limit value TL and the upper limit value TH of the corresponding temperature range TL-TH applied when the pressure Pd in the supply flow path 40 is the gauge pressure 0.0 MPa are set to the reference lower limit value TL0 (in Examples 1 to 3). 80 ° C.) and the standard upper limit TH0 (90 ° C. in Examples 1 to 3).
According to the following equation 1, the added value obtained by multiplying the pressure Pd in the supply flow path by the predetermined increase rate IRL is added to the reference lower limit value TL0 to obtain the pressure Pd in the supply flow path. The corresponding lower limit value TL is obtained, and at the same time,
According to the following equation 2, the added value obtained by multiplying the pressure Pd in the supply flow path by the predetermined increase rate IRH is added to the reference upper limit value TH0 to obtain the pressure Pd in the supply flow path. The corresponding upper limit value TH can be obtained (claim 5).
[Equation 1] TL = IRL x Pd + TL0
[Equation 2] TH = IRH × Pd + TH0

The range of pressure that can be taken by the pressure Pd in the supply flow path 40 is set for each predetermined numerical range (Pd ≤ 0.4 MPa, 0.4 MPa <Pd <0.6 MPa, 0.6 MPa ≤ Pd in Example 4). The corresponding temperature range TL-TH applied to each of the divided numerical ranges is set in advance (100-120 ° C./0.4MPa <Pd <0.6MPa in Example 4 when Pd ≦ 0.4MPa is 130). It may be set to 150-160 ° C. at −140 ° C./0.6MPa ≦ Pd) (claim 6).

The rotation speed F of the cooling fan 52 includes the minimum rotation speed FL, the maximum rotation speed FH, the lower limit value TL and the upper limit value TH of the corresponding temperature range TL-TH, and the temperature Td in the supply flow path 40. Based on the above, it may be obtained by the following formula 3 (claim 7).
[Equation 3] F = (FH-FL) / (TH-TL) × (Td-TL) + FL

The compressor body 10 is divided into a low-pressure stage compressor 11, a high-pressure stage compressor 12 that further compresses the compressed gas generated by the low-pressure stage compressor 11, the low-pressure stage compressor 11 and the high-pressure stage compressor 12. A multi-stage compressor body 10 equipped with an intermediate heat exchanger (intercooler) 13 provided between them is used.
Along with the heat exchanger (aftercooler) 51 provided in the supply flow path 40, the cooling air from the cooling fan 52 may be introduced into the intermediate heat exchanger (intercooler) 13 (claim). 8).

Further, the compressed gas cooling device 50 in the compressor of the present invention is
The compressor main body 10 that generates compressed gas, an intake control valve 31 that controls opening and closing of the intake port of the compressor main body 10, a supply flow path 40 from the discharge port of the compressor main body 10 to the consumption side, and the supply. A capacity control type that is provided with a check valve 41 provided in the flow path 40 and controls the pressure of the compressed gas supplied to the consumption side to approach a predetermined target pressure by controlling the intake amount by the intake control valve 31. In the compressor of
A heat exchanger 51 that cools the compressed gas passing through the supply flow path 40, a cooling fan 52 that introduces cooling air into the heat exchanger 51, a fan motor 53 that drives the cooling fan 52, and the heat exchanger. The temperature detecting means 56 for detecting the temperature Td in the supply flow path 40 on the primary side of the check valve 41 and the pressure Pd in the supply flow path 40 on the secondary side of the check valve 41. Based on the temperature Td in the supply flow path 40 detected by the pressure detecting means 55 and the temperature detecting means 56, and the pressure Pd in the supply flow path 40 detected by the pressure detecting means 55. A control device 54 for controlling the rotation speed of the fan motor 53 is provided.
The control device 54
The upper limit value TH and the lower limit value TL of the predetermined corresponding temperature range TL-TH determined based on the pressure Pd in the supply flow path 40 detected by the pressure detecting means 55, and the supply detected by the temperature detecting means 56. Compare with the temperature Td in the flow path 40,
When the temperature Td in the supply flow path 40 is less than the lower limit value TL of the corresponding temperature range TL-TH, the cooling fan 52 is operated at a predetermined minimum rotation speed FL.
When the temperature Td in the supply flow path 40 exceeds the upper limit value TH of the corresponding temperature range TL-TH, the cooling fan 52 is operated at a predetermined maximum rotation speed FH.
When the temperature Td in the supply flow path 40 is within the range of the corresponding temperature range TL-TH, according to the correspondence relationship between the temperature Td in the supply flow path 40 and the rotation speed F of the cooling fan 52 set in advance. The rotation speed of the cooling fan 52 is increased according to the increase in the temperature Td in the supply flow path 40 between the minimum rotation speed FL and the maximum rotation speed FH, and the temperature Td in the supply flow path 40 is decreased. It is characterized in that the control for lowering the rotation speed of the cooling fan 52 is performed (claim 9).

The control device 54
It is preferable to configure the corresponding temperature range TL-TH so as to increase the lower limit value TL and the upper limit value TH with respect to the increase in the pressure Pd in the supply flow path 40 (claim 10).

The control device 54
An increase in the lower limit value TL and the upper limit value TH set as different values for each numerical value range obtained by dividing the pressure range that can be taken by the pressure Pd in the supply flow path 40 into predetermined numerical values. The rate IRL and IRH may be stored, and the corresponding temperature range TL-TH may be determined based on the rate of increase IRL and IRH (claim 11).

The control device 54
In at least a part of the pressure range that the pressure Pd in the supply flow path 40 can take, the increase rate IRL of the lower limit value TL and the increase rate IRH of the upper limit value TH set to different values are stored. , The corresponding temperature range TL-TH may be determined based on the respective increase rates IRL and IRH (Claim 12).

The lower limit value of the corresponding temperature range TL-TH applied when the pressure Pd in the supply flow path 40 is 0.0 MPa is set as the reference lower limit value TL0, and the upper limit value is set as the reference upper limit value TH0.
The control device 54
According to the following equation 1, the added value obtained by multiplying the pressure Pd in the supply flow path 40 by the predetermined increase rate IRL is added to the reference lower limit value TL0, and the pressure in the supply flow path 40 is added. The lower limit value TL corresponding to Pd is obtained, and at the same time,
According to the following equation 2, the added value obtained by multiplying the pressure Pd in the supply flow path 40 by the predetermined increase rate IRH is added to the reference upper limit value TH0, and the pressure in the supply flow path 40 is added. The upper limit value TH corresponding to Pd may be obtained (claim 13).
[Equation 1] TL = IRL x Pd + TL0
[Equation 2] TH = IRH × Pd + TH0

The control device 54
Even if the preset corresponding temperature range TL-TH applied to each numerical range obtained by dividing the range of pressure that can be taken by the pressure Pd in the supply flow path 40 into predetermined numerical ranges is stored. Good (Claim 14).

The control device 54
The rotation speed F of the cooling fan 52 is the minimum rotation speed FL, the maximum rotation speed FH, the lower limit value TL and the upper limit value TH of the corresponding temperature range TL-TH, and the temperature Td in the supply flow path 40. Based on the above, it may be obtained by the following formula 3 (claim 15).
[Equation 3] F = (FH-FL) / (TH-TL) × (Td-TL) + FL

The compressor body 10 is divided into a low-pressure stage compressor 11, a high-pressure stage compressor 12 that further compresses the compressed gas generated by the low-pressure stage compressor 11, the low-pressure stage compressor 11 and the high-pressure stage compressor 12. A multi-stage compressor body 10 equipped with an intermediate heat exchanger (intercooler) 13 provided between them is used.
The cooling fan 52 may be configured to introduce cooling air into the intermediate heat exchanger (intercooler) 13 together with the heat exchanger (aftercooler) 51 provided in the supply flow path 40 (claimed). Item 16).

According to the configuration of the present invention described above, according to the method for cooling the compressed gas and the cooling device 50 in the compressor 1 of the present invention, the following remarkable effects can be obtained.

When the temperature Td in the supply flow path 40 is in a predetermined corresponding temperature range TL-TH in which the lower limit value TL and the upper limit value TH are determined based on the pressure Pd in the supply flow path 40 by the control device 54. According to the correspondence between the preset temperature Td in the supply flow path 40 and the rotation speed F of the cooling fan 52, the compressed gas temperature Td rises between the predetermined minimum rotation speed FL and the maximum rotation speed FH. The compressed gas discharged from the compressor main body 10 is configured to increase the rotation speed of the cooling fan 52 and reduce the rotation speed of the cooling fan 52 as the compressed gas temperature Td decreases. Can be appropriately cooled according to its temperature, pressure, and flow rate, and by efficiently introducing cooling air into the heat exchanger 51, the required cooling effect can be obtained and the consumed power can be reduced. By reducing it, we were able to save power.

Moreover, in this configuration, when the temperature Td in the supply flow path 40 is low, the rotation speed of the fan motor 53 is lowered to reduce the amount of cooling air introduced into the heat exchanger 51 by the cooling fan 52, thereby reducing the heat exchanger. It was also possible to prevent the occurrence of supercooling in 51.

The control device 54 determines the corresponding temperature range TL-TH so as to increase the lower limit value TL and the upper limit value TH with respect to the increase in the pressure Pd in the supply flow path 40 detected by the pressure detecting means 55. In such a configuration, by introducing an appropriate air volume according to the pressure Pd in the supply flow path 40 into the heat exchanger 51, it was possible to further reduce the power consumption and prevent the occurrence of supercooling. ..

That is, in the capacity control type compressor 1 to which the present invention is applied, when the compressed gas is consumed on the consuming side, the pressure in the supply flow path 40 reduced by the consumption of the compressed gas is predetermined. In order to maintain the target pressure of, the capacity control device 30 opens the intake control valve 31 to cause the compressor main body 10 to generate the compressed gas, so that a relatively large amount of compressed gas corresponding to the consumption on the consumption side is generated. Passes through the heat exchanger 51, so it is necessary to introduce a large amount of cooling air into the heat exchanger 51 in order to cool this large amount of compressed gas.

On the other hand, when the consumption of the compressed gas on the consumption side decreases or stops and the pressure in the supply flow path 40 rises to approach the target pressure or reaches the target pressure, the capacity control device 30 is compressed by the intake control valve 31. By narrowing or closing the intake port of the machine body 10 to reduce the amount of compressed gas produced by the compressor body 10 or to stop the generation of compressed gas, the amount of compressed gas passing through the heat exchanger 51 is reduced. Or, since the amount of compressed gas passing through the heat exchanger 51 becomes zero, if a large amount of cooling air is introduced into the heat exchanger 51 even in such a state, the heat exchanger 51 becomes overcooled and aggregated water. The heat exchanger 51 may be damaged due to freezing or heat shock.

Further, as introduced in Patent Document 2 described above, in an inverter-driven compressor in which the pressure (target pressure) of the compressed gas supplied to the consumption side is variable, the compressor body 10 can be changed by changing the setting of the target pressure. Since the rotation speed of the main motor 20 is changed according to the change in the target pressure setting so that the main motor 20 to be driven generates the rated output, when the target pressure is set to high pressure, the rotation speed decreases and the compressor body becomes The amount of compressed gas generated decreases, and when the target pressure is set to a low pressure, the rotation speed increases and the amount of compressed gas generated by the compressor body 10 increases.

Therefore, if the appropriate amount of air blown when the target pressure is set to high pressure is applied when the target pressure is set to low pressure, insufficient cooling of the compressed gas may occur, while the appropriate amount of air blown when the target pressure is set to low pressure. If is applied when the target pressure is set to high pressure, the compressed gas will be cooled more than necessary, which will consume extra power and may cause supercooling depending on the usage conditions. There is also.

However, as described above, as the pressure Pd in the supply flow path 40 on the secondary side of the check valve 41 increases, the lower limit value TL and the upper limit value TH are increased to move the corresponding temperature range TL-TH to the high temperature side. By shifting to, when the pressure Pd in the supply flow path 40 is low and a large amount of compressed gas is passing through the heat exchanger 51, the heat exchanger 51 is in a state where the temperature Td in the supply flow path 40 is low. On the other hand, when the pressure Pd in the supply flow path 40 is relatively high and the amount of compressed gas passing through the heat exchanger 51 is small or zero, the supply flow can be introduced. By not increasing the amount of cooling air introduced into the heat exchanger 51 until the temperature Td in the path 40 becomes a relatively high temperature, overcooling is prevented and heat due to freezing of aggregated water or heat shock is prevented. It is possible to prevent damage to the exchanger 51.

The control device 54 sets the increase rates IRL and IRH of the lower limit value TL and the upper limit value TH to different values for each numerical range of the pressure Pd in the supply flow path 40, and / or the supply flow path. In the configuration in which the increase rate IRL of the lower limit value TL and the increase rate IRH of the upper limit value TH are set to different values in at least a part of the range of the pressure that the pressure Pd in 40 can take, the compression to which the present invention is applied. It was possible to make more appropriate settings according to the characteristics of the machine.

The corresponding temperature range TL-TH is not determined by calculation by the control device 54, but the corresponding temperature range TL-TH applied in each predetermined numerical range of the pressure Pd in the supply flow path 40 is set in advance. It may be set, and this makes it possible to simplify the arithmetic processing performed by the control device 54 and simplify the device configuration and the like.

Explanatory drawing of the compressor provided with the compressed gas cooling apparatus of this invention. Explanatory drawing of the inverter drive type compressor provided with the compressed gas cooling apparatus of this invention. A flowchart illustrating the operation of the control device (Examples 1 to 3). Correlation diagram showing the change of the corresponding temperature range TL-TH with respect to the change of the pressure Pd in the supply flow path (Example 1). FIG. 6 is a correlation diagram (Example 1) showing a change in the rotation speed (output frequency of the inverter) of the fan motor with respect to a change in the temperature Td in the supply flow path. Correlation diagram showing the change of the corresponding temperature range TL-TH with respect to the change of the pressure Pd in the supply flow path (Example 2). FIG. 6 is a correlation diagram (Example 2) showing changes in the rotation speed (output frequency of the inverter) of the fan motor with respect to changes in the temperature Td in the supply flow path. The correlation diagram which showed the change of the corresponding temperature range TL-TH with respect to the change of the pressure Pd in a supply flow path (Example 3). FIG. 6 is a correlation diagram (Example 3) showing changes in the rotation speed (output frequency of the inverter) of the fan motor with respect to changes in the temperature Td in the supply flow path. FIG. 6 is a flowchart illustrating the operation of the control device (Example 4). FIG. 6 is a correlation diagram (Example 4) showing changes in the rotation speed (output frequency of the inverter) of the fan motor with respect to changes in the temperature Td in the supply flow path. Explanatory drawing of a conventional compressor (corresponding to FIG. 3 of Patent Document 1).

Hereinafter, the configuration of the present invention will be described with reference to the accompanying drawings.

[Overall configuration of engine-driven generator]
In FIGS. 1 and 2, reference numeral 1 is a compressor provided with the cooling device of the present invention, and the compressor 1 includes a compressor body 10 for compressing a gas to be compressed and a drive of the compressor body 10. The source 20, the intake control valve 31 for controlling the opening and closing of the intake port of the compressor main body 10, the supply flow path 40 from the discharge port of the compressor main body 10 to the consumption side, and the check valve 41 provided in the supply flow path are provided. A capacity control device that controls the intake amount of the compressor body 10 by operating the intake control valve 31 so that the pressure Pd in the supply flow path 40 on the secondary side of the check valve 41 approaches a predetermined target pressure. It is configured as a capacity control type compressor equipped with 30.

In the illustrated example, a configuration in which a main motor, which is an electric motor, is provided as the drive source 20 of the compressor main body 10 is shown, but instead of this configuration, the drive source of the compressor main body 10 is used as an engine. However, as long as the compressor body 10 can be driven, it may be configured by various known drive sources other than the motor and the engine.

In the above-mentioned supply flow path 40, a heat exchanger (aftercooler) 51 that cools the compressed gas discharged from the compressor body before being supplied to the consumption side, and cooling that introduces cooling air into the heat exchanger 51 are cooled. The compressed gas cooling device 50 of the present invention is provided, which includes a fan 52, a fan motor 53 for driving the cooling fan 52, and a control device 54 for controlling the rotation speed of the fan motor 53.

[Compressor body]
Among the components of the compressor 1 shown in FIGS. 1 and 2, the compressor body 10 described above is known as long as it can compress the compressed gas to generate the compressed gas and supply it to the consumption side. Various configurations can be adopted.

In the illustrated embodiment, the compressor main body 10 is used as a low-pressure compressor 11, a high-pressure compressor 12 for further compressing the compressed gas obtained by the low-pressure compressor 11, and a low-pressure compressor 11. It is composed of a two-stage oil-free screw compressor equipped with an intermediate heat exchanger (intercooler) 13 provided between the high-pressure stage compressor 12 and the high-pressure stage compressor 12.

However, the structure of the compressor main body 10 is not limited to the two-stage configuration shown in FIGS. 1 and 2, and may be a single-stage configuration or a multi-stage configuration of two or more stages. In the case of a single-stage configuration, the above-mentioned intermediate heat exchanger (intercooler) 13 can omit this, and in the case of a multi-stage configuration of two or more stages, each stage An intermediate heat exchanger 13 may be provided between the compressors.

Further, in the illustrated embodiment, the compressor main body 10 is configured by an oil-free screw compressor that does not require the introduction of cooling oil into the compression action space, but instead of this configuration, the compressor body 10 is formed in the compression action space. Various known configurations can be adopted, such as introducing cooling oil and configuring the compressor body 10 with an oil-cooled screw compressor.

When the compressor main body 10 has an oil-cooled configuration as described above, a receiver tank, an oil separator, or the like for separating cooling oil from the discharged compressed gas may be included in the compressor main body configuration. ..

[Capacity control device]
The intake port of the compressor body 10 described above, and in the illustrated example, the intake port of the low-pressure stage compressor 11 constituting the compressor body 10 is provided with an intake control valve 31 for controlling the intake of the compressed gas to the compressor body 10. A capacity control device 30 provided with a control device 54 that controls the operation of the intake control valve 31 according to the pressure of the compressed gas supplied to the consumption side is provided, and the capacity is consumed by the capacity control by the capacity control device 30. It is configured to be able to supply a compressed gas of a predetermined pressure to the side.

In the illustrated embodiment, the capacity control device 30 includes the pressure detecting means 55 provided in the supply flow path 40 on the secondary side of the check valve 41 in addition to the intake control valve 31 and the control device 54 described above. It is configured to be able to control the operation of the intake control valve 31 configured by the proportional control valve or the like based on the control signal output by the control device 54 based on the detection signal from the pressure detecting means 55.

As a result, the intake control valve 31 is opened and the supply flow flows when the pressure Pd in the supply flow path 40 drops according to the pressure Pd in the supply flow path 40 on the secondary side of the check valve 41 detected by the pressure detecting means 55. When the pressure Pd in the path 40 rises and approaches or reaches a predetermined target pressure, the intake control valve 31 is throttled or closed to control the intake amount of the compressor main body 10, thereby controlling the intake amount of the check valve 41 on the secondary side. The pressure Pd in the supply flow path, that is, the pressure of the compressed gas supplied to the consumption side is controlled so as to approach a predetermined target pressure.

In the illustrated embodiment, the control device 54 and the pressure detecting means 55, which are the components of the capacity control device 30, are shared with the control device 54 and the pressure detecting means 55, which are the components of the compressed gas cooling device 50 of the present invention. Although the number of parts is reduced by doing so, the capacity control device 30 and the compressed gas cooling device 50 may be provided as independent configurations.

As shown in FIG. 2, when an inverter type compressor provided with an inverter 21 for controlling the rotation speed of the main motor 20 for driving the compressor main body 10 is to be controlled, the above-mentioned control device 54 is used for intake control. Not only the operation of the valve 31 is controlled, but also the inverter 21 is controlled to increase the rotation speed of the main motor 20 in response to the decrease in the pressure Pd in the supply flow path 40, and the pressure Pd in the supply flow path 40 increases. On the other hand, the rotation speed of the compressor body may be controlled to reduce the rotation speed of the main motor 20, and the pressure of the compressed gas supplied to the consumption side is targeted by the combined use of intake control and rotation speed control. The above-mentioned capacity control that approaches the pressure may be performed.

When the inverter type compressor is targeted as described above, the above-mentioned target pressure setting may be variable as in the compressor described in Patent Document 2 described above.

The configuration of the capacity control device 30 is not limited to the configuration of the illustrated embodiment, and various known configurations can be adopted.

[Compressed gas cooling device]
Example 1
The compressor 1 configured as described above is provided with the compressed gas cooling device 50 of the present invention for cooling the compressed gas generated by the compressor main body 10 described above.

The compressed gas cooling device 50 includes a heat exchanger (aftercooler) 51 provided in the above-mentioned supply flow path 40, a cooling fan 52 that introduces cooling air into the heat exchanger (aftercooler) 51, and the cooling fan 52. 53, a temperature detecting means 56 for detecting the temperature Td in the supply flow path 40 on the primary side of the heat exchanger 51, and the supply flow path 40 on the secondary side of the check valve 41. Based on the detection signal of the pressure detecting means 55 for detecting the pressure Pd and the detection signal of the temperature detecting means 56 and the detection signal of the pressure detecting means 55, the power supplied to the fan motor 53 is controlled to control the rotation speed of the fan motor 53. A control device 54 for controlling is provided.

As shown in FIGS. 1 and 2, when the compressor main body 10 has a multi-stage configuration including an intermediate heat exchanger (intercooler) 13, the intermediate heat exchanger (intercooler) 13 is used. The heat exchanger (aftercooler) provided in the supply flow path 40 is provided with the cooling air from the cooling fan 52 by arranging it in a common shroud 60 together with the heat exchanger (aftercooler) 51 provided in the supply flow path 40. It may be possible to introduce it not only to the 51 but also to the intermediate heat exchanger (intercooler) 13.

Further, the pressure detecting means 55 and the control device 54, which are the components of the compressed gas cooling device 50 of the present invention, may be shared with the pressure detecting means and the control device, which are the components of the capacity control device 30, as described above. Also, the temperature detecting means 56 is shared with the temperature detecting means for emergency stop (for abnormal temperature detection) provided as a safety device in the compressor 1, and the cost increases due to the increase in the number of parts. It may be suppressed.

Further, in the illustrated embodiment, the above-mentioned fan motor 53 is configured by a three-phase AC motor, an inverter 57 for the fan motor 53 is provided, and the fan motor 53 is connected to the fan motor 53 by a control signal from the control device 54. The rotation speed of the fan motor 53 can be controlled by controlling the frequency of the electric power supplied to the inverter.

However, the rotation speed control of the fan motor 53 is not limited to this configuration. For example, the fan motor 53 is configured by a DC motor, and the control device 54 changes the current value supplied to the fan motor 53 from the DC power supply to change the fan. The rotational speed of the motor 53 may be changed, and is known as long as the rotational speed of the fan motor 53, and therefore the amount of cooling air introduced into the heat exchanger 51 by the cooling fan 52, can be changed. Various configurations can be adopted.

The rotation speed of the fan motor 53 is a control device based on the pressure Pd in the supply flow path 40 detected by the pressure detecting means 55 and the temperature Td in the supply flow path 40 detected by the temperature detecting means 56. According to 54, as shown in the flowchart in FIG. 3, the procedure is as follows.

When the control device 40 receives the detection signals from the temperature detecting means 56 and the pressure detecting means 55 (S1-1), the pressure Pd detected based on the pressure Pd in the supply flow path 40 detected by the pressure detecting means 55. The corresponding temperature range TL-TH, which is the reference for the rotation speed control of the fan motor 53 corresponding to the above, is calculated (S1-2).

In the calculation (S1-2) of the corresponding temperature range TL-TH based on the pressure Pd in the supply flow path 40 detected by the pressure detecting means 55, the lower limit value TL and the upper limit value TH of the corresponding temperature range TL-TH are described above. It is performed so as to increase with increasing pressure Pd in the supply flow path 40.

The calculation of the lower limit value TL and the upper limit value TH of the corresponding temperature range TL-TH is, for example, the corresponding temperature range TL-TH applied when the pressure Pd in the supply flow path is the gauge pressure 0.0 MPa. The lower limit is the reference lower limit TL0, and the upper limit is the reference upper limit TH0.
Detection is performed by adding the added value obtained by multiplying the pressure Pd in the supply flow path 40 by the preset lower limit value TL increase rate IRL to the reference lower limit value TL0 according to the following equation 1. The lower limit value TL corresponding to the pressure Pd in the supply flow path 40 is obtained, and the increase rate IRH for the upper limit value TH set in advance is set to the pressure Pd in the supply flow path by the following equation 2. By adding the added value obtained by multiplication to the reference upper limit value TH0, the upper limit value TH corresponding to the detected pressure Pd in the supply flow path 40 can be obtained.
[Equation 1] TL = IRL x Pd + TL0
[Equation 2] TH = IRH × Pd + TH0

In this embodiment, as an example, the reference lower limit value TL0 is set to 80 ° C., the reference upper limit value TH0 is set to 90 ° C., and the increase rate IRL of the lower limit value TL and the increase rate IRH of the upper limit value TH are both the same value. It is set as a constant value (100 as an example) that does not change even if the pressure Pd in the supply flow path 40 changes.

The change in the temperature range TL-TH (change in the lower limit value TL and the upper limit value TH) corresponding to the change in the pressure Pd in the supply flow path 40 in this example is shown in FIG. The calculated values of the corresponding temperature range TL-TH (lower limit value TL and upper limit value TH) at 0.4 MPa, 0.5 MPa, and 0.7 MPa are shown in Table 1 below.

In this way, when the corresponding temperature range TL-TH in this pressure Pd is calculated based on the pressure Pd in the supply flow path 40 detected by the pressure detecting means 55, the control device 54 determines the corresponding temperature range. The temperature Td in the supply flow path 40 detected by the TL-TH and the temperature detecting means 56 is compared (S1-3).

As a result of this comparison, when the temperature Td in the supply flow path 40 is less than the lower limit value TL (Td <TL) of the corresponding temperature range TL-TH described above, the cooling fan 52 is operated at a predetermined minimum rotation speed FL. (S1-4).

Further, when the temperature Td in the supply flow path 40 exceeds the upper limit value TH of the corresponding temperature range TL-TH described above, the cooling fan 52 is operated at the maximum rotation speed FH when TH <Td (S1). -5).

Further, when the temperature Td in the supply flow path 40 is within the range of the above-mentioned corresponding temperature range TL-TH (TL ≦ Td ≦ TH), a preset correspondence relationship is shown in the following equation 3 as an example. According to the correspondence relationship, the rotation speed of the cooling fan 52 is increased or decreased between the minimum rotation speed FL and the maximum rotation speed FH according to the temperature Td in the supply flow path 40 (S1-6).
[Equation 3] F = (FH-FL) / (TH-TL) × (Td-TL) + FL

Based on the calculation results of the lower limit TL and upper limit TH of the corresponding temperature range TL-TH shown in Table 1 above, the pressures Pd in the supply flow path 40 are 0.4 MPa, 0.5 MPa, and 0.7 MPa, respectively. FIG. 5 shows a change in the rotation speed (output frequency of the inverter) of the fan motor 53 with respect to a change in the temperature Td in the supply flow path at a certain time.

As described above, in the compressor provided with the compressed gas cooling device 50 of the present invention, when the temperature Td in the supply flow path 40 is within the range of the corresponding temperature range TL-TH described above, the temperature in the supply flow path 40 is reached. By changing the amount of cooling air introduced into the heat exchanger 51 according to the change in Td, the amount of cooling air is reduced when the temperature in the supply flow path 40 is low and the need for cooling is small, thereby causing overcooling. While preventing this, the power consumption of the fan motor 53 can be reduced to save energy, and the wind noise of the cooling fan 52 can be reduced, so that quietness during operation can be obtained.

Moreover, as shown in FIG. 4, the lower limit value TL and the upper limit value TH of the corresponding temperature range TL-TH described above are changed so as to increase according to the increase of the pressure Pd in the supply flow path. A state in which the pressure Pd in the supply flow path 40 drops due to the consumption of the compressed gas on the consumption side, the intake control valve 31 is opened by the capacity control device 30, and the compressor main body 10 generates the compressed gas. That is, in a state where a large amount of compressed gas is passing through the heat exchanger 51 provided in the supply flow path 40, the amount of cooling air introduced increases from the state where the temperature Td in the supply flow path 40 is relatively low. It is possible to suitably cool a large amount of compressed gas passing through the heat exchanger 51.

On the other hand, the consumption of the compressed gas on the consumption side decreases, or the consumption of the compressed gas stops, the pressure in the supply flow path 40 rises, the intake port of the compressor main body 10 is closed, and the compressed gas becomes available. When the amount of gas produced has decreased or the production of compressed gas has stopped, that is, when the amount of compressed gas passing through the heat exchanger 51 has decreased or the amount of compressed gas passing through the heat exchanger 51 has become zero. The configuration is such that the amount of cooling air introduced into the heat exchanger 51 is not increased until the temperature Td in the supply flow path 40 becomes a relatively high temperature, which causes damage due to overcooling of the heat exchanger 51. Etc. are preferably prevented.

When a freezing dryer (not shown) is provided on the consumption side, the temperature Td in the supply flow path 40, that is, the inlet air temperature of the freezing dryer is predetermined by preventing supercooling of the compressed gas. Since the temperature is kept above the temperature, it is possible to suitably prevent the occurrence of freezing in the freezing dryer pipe.

Example 2
In the example introduced as Example 1, the increase rate IRL of the lower limit value TL and the increase rate IRH of the upper limit value TH in the corresponding temperature range TL-TH are the same value, and are constant and do not change due to the change of the pressure Pd of the supply flow path. A configuration example using a value (“100” as an example) has been described.

On the other hand, in this embodiment (Example 2), the pressure range that the pressure Pd in the supply flow path can take is divided into predetermined numerical ranges, and the lower limit of the corresponding temperature range TL-TH is divided for each divided numerical range. The increase rates IRL and IRH of the value TL and the upper limit value TH are set to different values, and in this embodiment, the increase rates IRL and IRH also increase as the pressure Pd in the supply flow path 40 increases. I set it.

As such a configuration example, in this embodiment, as an example, the reference lower limit value TL0 is set to 80 ° C., the reference upper limit value is set to 90 ° C., and the increase rate IRL of the lower limit value TL and the increase rate IRL of the upper limit value TH are the same. As a value, when the pressure Pd in the supply flow path is 0.4 MPa or less (Pd ≤ 0.4 MPa), the increase rate IRL and IRH are both set to "50", whereas the pressure in the supply flow path is set to "50". When Pd exceeded 0.4 MPa (Pd> 0.4 MPa), the rate of increase IRL and IRH were both doubled to "100".

FIG. 6 shows the change of the corresponding temperature range TL-TH (lower limit value TL and upper limit value TH) with respect to the change of the pressure Pd in the supply flow path 40 in this example.

Table 2 shows the results of calculating the lower limit value TL and the upper limit value TH when the pressures Pd in the supply flow path are 0.4 MPa, 0.5 MPa, and 0.7 MPa.

Further, FIG. 7 shows a change in the rotation speed (inverter output frequency) of the fan motor 53 with respect to a change in the temperature Td in the supply flow path 40 based on the calculation results of the lower limit value TL and the upper limit value TH shown in Table 2. ..

In this embodiment, when the pressure Pd in the supply flow path is as low as 0.4 MPa or less (Pd ≦ 0.4 MPa), the cooling air volume is increased from a lower temperature than in the embodiment described with reference to FIG. It can be increased, for example, as in the case of an inverter-driven compressor that can change the target pressure setting, the target pressure setting is lowered and the amount of low-pressure compressed gas generated is increasing. Even when applied to a compressor or the like, cooling can be suitably performed.

Example 3
In the configuration examples described above as Example 1 and Example 2, the increase rate IRL of the lower limit value TL of the corresponding temperature range TL-TH and the increase rate IRH of the upper limit value TH are set to the same value. Therefore, Even if the pressure Pd in the supply flow path 40 changes, the width of the corresponding temperature range TL-TH, that is, the difference between the lower limit value TL and the upper limit value TH does not change at a constant level (10 ° C.).

On the other hand, in this embodiment (Example 3), the reference lower limit value TL0 is set to 80 ° C. and the reference upper limit value is set to 90 ° C., which is the same as in the above-mentioned Examples 1 and 2, but the supply flow path. When the internal pressure Pd was 0.4 MPa or less (Pd ≦ 0.4 MPa), the increase rate IRL of the lower limit value TL was set to “50”, and the increase rate IRL of the upper limit value TH was set to a value different from “75”.

Also in this embodiment, both the lower limit value TL increase rate IRL and the upper limit value TH increase rate IRH when the pressure Pd in the supply flow path exceeds 0.4 MPa (Pd> 0.4 MPa). The point set as the same "100" is the same as in Example 1 and Example 2 described above, but even in the range of Pd> 0.4 MPa, the increase rate of the lower limit value TL and the increase rate of the upper limit value TH. IRH may be set to a different value.

FIG. 8 shows the change in the temperature range TL-TH corresponding to the change in the pressure Pd in the supply flow path 40 in this configuration example.

Table 3 shows the results of calculating the lower limit value TL and the upper limit value TH when the pressures Pd in the supply flow path are 0.4 MPa, 0.5 MPa, and 0.7 MPa.

Further, using the lower limit value TL and the upper limit value TH obtained in Table 3, the supply when the pressure Pd in the supply flow path is 0.4 MPa, 0.5 MPa, 0.7 MPa, which is obtained based on Equation 3. FIG. 9 shows the relationship between the change in the rotation speed of the fan motor (the output frequency of the inverter) and the change in the temperature Td in the flow path 40.

As described above, in this embodiment (Example 3), the temperature Td in the supply flow path is changed for each predetermined pressure range (Pd ≦ 0.4 MPa range and Pd> 0.4 MPa range). The inclination of the change in the rotation speed of the fan motor can be set to be different, and the cooling state can be set according to the characteristics of each compressor.

Example 4
In Examples 1 to 3 described above, the corresponding temperature range TL-TH also continuously changes with respect to the continuous change of the pressure Pd in the supply flow path 40 detected by the pressure detecting means 55. Configured.

On the other hand, in this embodiment (Example 4), the pressure range that can be taken by the pressure Pd in the supply flow path is divided into a plurality of values for each predetermined numerical range, and the pressure in the numerical range is divided for each numerical range. The configuration is such that the corresponding temperature range TL-TH, which is commonly applied to Pd, is set.

As an example, in the present embodiment, the pressure range that the pressure Pd in the supply flow path 40 can take is set to three ranges of Pd ≦ 0.4 MPa, 0.4 MPa <Pd <0.6 MPa, and 0.6 MPa ≦ Pd. It was divided and the corresponding temperature range TL-TH described above was set as shown in Table 4 below for each numerical range.

The processing procedure by the control device 54 in the present embodiment (Example 4) will be described with reference to the flowchart shown in FIG.

When the control device 54 receives the detection signals from the temperature detecting means 56 and the pressure detecting means 55 (S2-1), the control device 54 changes the pressure Pd in the supply flow path 40 detected by the pressure detecting means 55 to Pd ≦. It is determined in which range of 0.4MPa, 0.4MPa <Pd <0.6MPa, and 0.6MPa ≦ Pd (S2-2).

Then, according to Table 4 above, the control device 54 determines that the pressure Pd in the supply flow path 40 is in the range of Pd ≦ 0.4 MPa, and sets the above-mentioned corresponding temperature range TL-TH to 100-120 ° C. ( S2-3) If it is determined that the pressure Pd in the supply flow path is in the range of 0.4 MPa <Pd <0.6 MPa, the above-mentioned corresponding temperature range TL-TH is set to 130-140 ° C. (S2-4). If it is determined that the pressure Pd in the supply flow path is in the range of 0.6 MPa ≦ Pd, the above-mentioned corresponding temperature range TL-TH is set to 150-160 ° C. (S2-5).

In this way, when the corresponding temperature range TL-TH corresponding to this pressure Pd is determined based on the pressure Pd in the supply flow path 40 detected by the pressure detecting means 55, the control device determines the determined response. The lower limit value TL and the upper limit value TH of the temperature range TL-TH are compared with the temperature Td in the supply flow path detected by the temperature detecting means (S2-6).

As a result of this comparison, when the temperature Td in the supply flow path is less than the lower limit value TL of the corresponding temperature range TL-TH described above, the cooling fan 52 is operated at a predetermined minimum rotation speed FL (S2-7).

Further, when the temperature Td in the supply flow path 40 exceeds the upper limit value TH of the corresponding temperature range TL-TH described above, the cooling fan 52 is operated at the maximum rotation speed FH (S2-8).

Further, when the temperature Td in the supply flow path 40 is within the range of the corresponding temperature range TL-TH described above, the temperature in the supply flow path 40 is according to a preset correspondence relationship, for example, the above-mentioned equation 3. The rotation speed of the cooling fan is increased or decreased between the minimum rotation speed FL and the maximum rotation speed FH according to Td (S2-9).

In this example, when the pressure Pd in the supply flow path 40 is in the range of Pd ≦ 0.4 MPa, when it is in the range of 0.4 MPa <Pd <0.6 MPa, and in the range of 0.6 MPa ≦ Pd. FIG. 11 shows the change in the rotation speed (output frequency of the inverter) of the fan motor with respect to the change in the temperature Td in each supply flow path when it is inside.

Also in the configuration example of this embodiment, not only the compressed gas can be appropriately cooled based on the pressure Pd in the supply flow path 40 and the temperature in the supply flow path 40, but also the control device 54 does not have to perform the calculation. Since the corresponding temperature range TL-TH can be determined, the configuration (program) of the control device 54 can be easily performed.

Moreover, since the corresponding temperature range TL-TH of the pressure Pd in the supply flow path 40 can be appropriately set regardless of the calculation formula, for example, it is an inverter-driven compressor capable of setting the target pressure described above. Therefore, the compressed gas can be optimally cooled even for a compressor whose characteristics change each time the target pressure is set.

1 Compressor 10 Compressor body 11 Low-pressure stage compressor 12 High-pressure stage compressor 13 Intermediate heat exchanger (intercooler)
20 Drive source (main motor)
21 Inverter 30 Capacity control device 31 Intake control valve 40 Supply flow path 41 Check valve 50 Compressed gas cooling device 51 Heat exchanger (aftercooler)
52 Cooling fan 53 Fan motor 54 Control device 55 Pressure detecting means 56 Temperature detecting means 57 Inverter for fan motor 60 Shellaud 100 Compressor 110 Compressor body 131 Intake control valve 151 Heat exchanger (aftercooler)
152 Cooling fan 154 Control device 155 Pressure detection means Pd Pressure in the supply flow path Td Temperature in the supply flow path TL-TH Corresponding temperature range TL Corresponding temperature range Lower limit TH Corresponding temperature range upper limit F Cooling fan rotation speed FL Minimum rotation speed of cooling fan FH Maximum rotation speed of cooling fan Increase rate of lower limit of IRL compatible temperature range Increase rate of upper limit value of IRH compatible temperature range TL0 Reference lower limit value TH0 Reference upper limit value

Claims (16)

The compressor body that generates compressed gas, the intake control valve that controls the opening and closing of the intake port of the compressor body, the supply flow path from the discharge port of the compressor body to the consumption side, and the supply flow path are provided. In a capacity-controlled compressor equipped with a check valve and controlling the pressure of the compressed gas supplied to the consumption side to approach a predetermined target pressure by controlling the intake amount by the intake control valve.
A heat exchanger for cooling the compressed gas passing through the supply flow path and a cooling fan for introducing cooling air into the heat exchanger are provided.
The lower limit (TL) and upper limit (TH) of a predetermined corresponding temperature range (TL-TH) determined based on the pressure (Pd) in the supply flow path on the secondary side of the check valve, and the above. Compare with the temperature (Td) in the supply flow path on the primary side of the heat exchanger and the primary side of the check valve.
When the temperature (Td) in the supply flow path is less than the lower limit value (TL) in the corresponding temperature range, the cooling fan is operated at a predetermined minimum rotation speed (FL).
When the temperature (Td) in the supply flow path exceeds the upper limit value (TH) in the corresponding temperature range (TL-TH), the cooling fan is operated at a predetermined maximum rotation speed (FH).
When the temperature (Td) in the supply flow path is within the corresponding temperature range (TL-TH), the preset temperature (Td) in the supply flow path and the rotation speed (F) of the cooling fan are set in advance. ), The rotation speed (F) of the cooling fan is increased according to the increase in the temperature (Td) in the supply flow path between the minimum rotation speed (FL) and the maximum rotation speed (FH). A method for cooling a compressed gas in a compressor, which comprises lowering the rotation speed (F) of the cooling fan according to a decrease in the temperature (Td) in the supply flow path. A claim characterized in that the corresponding temperature range (TL-TH) is determined so that the lower limit value (TL) and the upper limit value (TH) increase with respect to an increase in pressure (Pd) in the supply flow path. Item 1. The method for cooling a compressed gas in the compressor according to item 1. The range of pressure that the pressure (Pd) in the supply flow path can take is divided into predetermined numerical ranges, and the rate of increase of the lower limit value (TL) and the upper limit value (TH) is divided for each numerical range. The method for cooling a compressed gas in a compressor according to claim 2, wherein (IRL, IRH) are set to different values. The increase rate (IRL) of the lower limit value (TL) and the increase rate (IRH) of the upper limit value (TH) are set in at least a part of the pressure range that the pressure (Pd) in the supply flow path can take. The method for cooling a compressed gas in a compressor according to claim 2 or 3, wherein the values are set to different values. The lower limit value (TL) and the upper limit value (TH) of the corresponding temperature range (TL-TH) applied when the pressure (Pd) in the supply flow path is 0.0 MPa of the gauge are set to the reference lower limit value (TH), respectively. TL0) and standard upper limit (TH0)
According to the following equation 1, the added value obtained by multiplying the pressure (Pd) in the supply flow path by the predetermined increase rate (IRL) for the lower limit value (TL) is the reference lower limit value (TL0). ) To obtain the lower limit value (TL) corresponding to the pressure (Pd) in the supply flow path.
According to the following equation 2, the added value obtained by multiplying the pressure (Pd) in the supply flow path by the predetermined increase rate (IRH) for the upper limit value (TH) is the reference upper limit value (TH0). ), The upper limit value (TH) corresponding to the pressure (Pd) in the supply flow path is obtained, and the method for cooling the compressed gas in the compressor according to claim 3 or 4.
[Equation 1] TL = IRL x Pd + TL0
[Equation 2] TH = IRH × Pd + TH0 The range of pressure that can be taken by the pressure (Pd) in the supply flow path is divided into predetermined numerical ranges, and the corresponding temperature range (TL-TH) applied to each divided numerical range is set in advance. The method for cooling a compressed gas in the compressor according to claim 2. The rotation speed (F) of the cooling fan is the minimum rotation speed (FL), the maximum rotation speed (FH), the lower limit value (TL) and the upper limit value (TH) of the corresponding temperature range (TL-TH). The method for cooling a compressed gas in a compressor according to claim 5 or 6, wherein the method is obtained by the following formula 3 based on the temperature (Td) in the supply flow path.
[Equation 3] F = (FH-FL) / (TH-TL) × (Td-TL) + FL The compressor body is provided between a low-pressure stage compressor, a high-pressure stage compressor that further compresses the compressed gas generated by the low-pressure stage compressor, and an intermediate between the low-pressure stage compressor and the high-pressure stage compressor. A multi-stage compressor body equipped with a heat exchanger
The compressor according to any one of claims 1 to 7, wherein the cooling air from the cooling fan is introduced into the intermediate heat exchanger together with the heat exchanger provided in the supply flow path. How to cool the compressed gas in. The compressor body that generates compressed gas, the intake control valve that controls the opening and closing of the intake port of the compressor body, the supply flow path from the discharge port of the compressor body to the consumption side, and the supply flow path are provided. In a capacity-controlled compressor equipped with a check valve and controlling the pressure of the compressed gas supplied to the consumption side to approach a predetermined target pressure by controlling the intake amount by the intake control valve.
A heat exchanger that cools the compressed gas passing through the supply flow path, a cooling fan that introduces cooling air into the heat exchanger, a fan motor that drives the cooling fan, and the primary side and the reverse of the heat exchanger. A temperature detecting means for detecting the temperature (Td) in the supply flow path on the primary side of the stop valve, a pressure detecting means for detecting the pressure (Pd) in the supply flow path on the secondary side of the check valve, and a pressure detecting means. , Control to control the rotation speed of the fan motor based on the temperature (Td) in the supply flow path detected by the temperature detecting means and the pressure (Pd) in the supply flow path detected by the pressure detecting means. Install the device,
The control device
The upper limit value (TH) and lower limit value (TL) of a predetermined corresponding temperature range (TL-TH) determined based on the pressure (Pd) in the supply flow path detected by the pressure detecting means, and the temperature detecting means. Compared with the temperature (Td) in the supply flow path detected by
When the temperature (Td) in the supply flow path is less than the lower limit value (TL) in the corresponding temperature range (TL-TH), the cooling fan is operated at a predetermined minimum rotation speed (FL).
When the temperature (Td) in the supply flow path exceeds the upper limit value (TH) of the corresponding temperature range (TL-TH), the cooling fan is operated at a predetermined maximum rotation speed (FH).
When the temperature (Td) in the supply flow path is within the corresponding temperature range (TL-TH), the preset temperature (Td) in the supply flow path and the rotation speed (F) of the cooling fan are set in advance. ), The rotation speed of the cooling fan is increased according to the increase in the temperature (Td) in the supply flow path between the minimum rotation speed (FL) and the maximum rotation speed (FH), and the supply flow is increased. A compressed gas cooling device in a compressor, which controls to lower the rotation speed of the cooling fan according to a decrease in the temperature (Td) in the path. The control device is
A claim characterized in that the corresponding temperature range (TL-TH) is determined so as to increase the lower limit value (TL) and the upper limit value (TH) with respect to an increase in pressure (Pd) in the supply flow path. Item 9. The compressed gas cooling device in the compressor according to item 9. The control device is
The lower limit value (TL) and the upper limit value set as different values for each numerical value range obtained by dividing the pressure range that can be taken by the pressure (Pd) in the supply flow path into predetermined numerical values. 10. The compression according to claim 10, wherein the rate of increase (IRL, IRH) of (TH) is stored and the corresponding temperature range (TL-TH) is determined based on the rate of increase (IRL, IRH). Compressed gas cooling device in the machine. The control device
The rate of increase (IRL) of the lower limit value (TL) and the upper limit value (TH) set to different values in at least a part of the range of pressure that the pressure (Pd) in the supply flow path can take. The compressed gas cooling device in a compressor according to claim 10 or 11, wherein the rate of increase (IRH) is stored and the corresponding temperature range is determined based on each rate of increase (IRL, IRH). The lower limit value of the corresponding temperature range (TL-TH) applied when the pressure (Pd) in the supply flow path is 0.0 MPa is the reference lower limit value (TL0), and the upper limit value is the reference upper limit value (TH0). )age,
The control device
According to the following equation 1, the added value obtained by multiplying the pressure (Pd) in the supply flow path by the predetermined increase rate (IRL) for the lower limit value (TL) is the reference lower limit value (TL0). ) To obtain the lower limit value (TL) corresponding to the pressure (Pd) in the supply flow path.
According to the following equation 2, the added value obtained by multiplying the pressure (Pd) in the supply flow path by the predetermined increase rate (IRH) for the upper limit value (TH) is the reference upper limit value (TH0). The compressed gas cooling device in the compressor according to claim 11 or 12, wherein the upper limit value (TH) corresponding to the pressure (Pd) in the supply flow path is obtained in addition to the above.
[Equation 1] TL = IRL x Pd + TL0
[Equation 2] TH = IRH × Pd + TH0 The control device
The preset corresponding temperature range (TL-TH) applied to each numerical range obtained by dividing the range of pressure that can be taken by the pressure (Pd) in the supply flow path into predetermined numerical ranges is stored. The compressed gas cooling device in the compressor according to claim 10. The control device
The rotation speed (F) of the cooling fan is the minimum rotation speed (FL), the maximum rotation speed (FH), the lower limit value (TL) and the upper limit value (TH) of the corresponding temperature range (TL-TH). , And the compressed gas cooling device in the compressor according to claim 13 or 14, wherein the temperature (Td) in the supply flow path is obtained by the following formula 3.
[Equation 3] F = (FH-FL) / (TH-TL) × (Td-TL) + FL The compressor body is provided between a low-pressure stage compressor, a high-pressure stage compressor that further compresses the compressed gas generated by the low-pressure stage compressor, and an intermediate between the low-pressure stage compressor and the high-pressure stage compressor. A multi-stage compressor body equipped with a heat exchanger
The invention according to any one of claims 9 to 15, wherein the cooling fan is configured to introduce cooling air into the intermediate heat exchanger together with the heat exchanger provided in the supply flow path. Compressed gas cooling device in a compressor.

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