JP2735739B2 - Oilless compressor and start-up method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oilless compressor for compressing a gas having a boiling point higher than room temperature, and a method of starting the compressor.

[0002]

2. Description of the Related Art Conventionally, as an oilless compressor which compresses a gas having a boiling point higher than room temperature, that is, a gas which is in a liquefied state at room temperature,
The compressor shown in FIG. 6 is known. The compressor is provided with a cooling water jacket for cooling the rotor chamber around a rotor chamber (not shown) in the compressor main body 3 connected to the suction flow path 1 on one side and the discharge flow path 2 on the other side. A water supply channel 4 and a drain channel 5 are provided for use. Further, a bypass flow path 7 is provided from the discharge flow path 2 to the suction flow path 1 directly via the bypass valve 6. The oilless compressor is of a type that does not cool the gas to be compressed by injecting cooling oil into the rotor chamber, and in order to suppress the thermal expansion of the casing of the compressor body 3 due to the high heat of the compressed gas. ,Normal,
The cooling water jacket is provided on the outer periphery of the rotor chamber.

In the case of a compressor for compressing a gas having a boiling point higher than room temperature, in order to avoid liquid compression, the temperature of the casing and the rotor chamber of the compressor must be higher than room temperature before starting, more precisely, the gas to be compressed. It is necessary to prevent the suction gas from being liquefied by heating to a temperature higher than the temperature at which the gas is liquefied. For this reason, when the compressor is started, the compressor is operated using air or N ₂ gas whose boiling point is lower than room temperature, and the bypass valve 6 is opened to gradually discharge the high-temperature discharge gas into the suction passage. By returning to 1, the suction gas temperature is raised, and the temperature of the entire gas flow path in the casing including the rotor chamber is raised. After the temperature rise, the gas in the system is gradually replaced with a real gas, that is, a gas to be compressed having a boiling point higher than room temperature. Also, at the time of starting the compressor, a high-temperature gas is introduced into the system without flowing water through the cooling water jacket, and after the temperature of the entire gas flow path is increased, an operation using actual gas is started. Things have also been done.

[0004]

In the above-mentioned conventional apparatus,
After starting the compressor and raising the temperature of the entire gas flow path,
The replacement with the actual gas is performed, but the time required for the replacement of the gas is long, and it is necessary to discharge the discharge gas to a flare or the like during the replacement. Usually, this actual gas is expensive, and there is a problem that a large loss occurs due to the release of the actual gas. In addition, if the entire gas flow path is heated by the high-temperature gas without passing through the cooling water jacket, when the cooling water flows after the compressor is started, the cooling water jacket is rapidly cooled, and the casing is cracked. Problem arises. SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and can reduce loss due to gas discharge at the time of starting a compressor, and can prevent liquid compression and cracks due to rapid thermal deformation of a casing of a compressor body. And a method of starting the same.

[0005]

According to a first aspect of the present invention, a cooling water jacket for cooling a rotor chamber is provided around a rotor chamber in a casing of a compressor body, and a boiling point is higher than room temperature. In an oilless compressor that compresses gas, a high-temperature fluid flow path that is provided to be capable of cooling water heating by being joined to a water supply path that supplies cooling water to the cooling water jacket,
A calorie adjusting means for adjusting the amount of heat given to the cooling water from the high-temperature fluid flow path, including the cooling water jacket, at any point in the flow path of the water heated by the high-temperature fluid flow path The temperature of the water and at least one of the walls of the flow path is detected, and based on the detected temperature, while preventing the rate of change of the detected temperature with respect to time from exceeding an allowable value, A temperature controller that operates the calorie control means to increase the calorie before the compressor is started to increase the temperature of the flow path through which the gas passes, and to reduce the calorie after the temperature rise and after the compressor is started. And formed.

According to a second aspect of the present invention, there is provided an oilless compressor comprising a cooling water jacket for cooling a rotor chamber around a rotor chamber in a casing of a compressor body and compressing a gas having a boiling point higher than room temperature. A high-temperature fluid channel provided to be capable of heating the cooling water via a heat exchanger provided in a water supply channel for supplying the cooling water to the cooling water jacket; and a flow control valve provided to be capable of adjusting the fluid flow rate in the high-temperature fluid channel. And, including the cooling water jacket, the water at any point in the flow path of the water heated by the high-temperature fluid flow path, and the temperature of at least one of the walls of the flow path. Based on the detected temperature, operate the flow rate control valve to increase the fluid flow rate before starting the compressor while preventing the rate of change of the detected temperature with respect to time from exceeding an allowable value. Let me above Scan thereby is the temperature of the flow path through, after heating, and after the compressor starts, is formed by providing a temperature controller for reducing the fluid flow rate.

Further, a third aspect of the present invention is directed to an oilless compressor including a cooling water jacket for cooling a rotor chamber around a rotor chamber in a casing of a compressor body and compressing a gas having a boiling point higher than room temperature. Heating means for increasing the temperature of at least the wall of the gas flow path in the casing, including the rotor chamber, through which the gas flows; heat quantity adjusting means for increasing or decreasing the amount of heat applied to the wall by the heating means; And operating the calorific value adjusting means based on the detected temperature to increase the caloric value before starting the compressor while preventing the rate of change of the detected temperature with respect to time from exceeding an allowable value. After the temperature of the rotor chamber was raised and after the compressor was started, a temperature controller for reducing the amount of heat was provided.

In a fourth aspect of the present invention, the heating means is a heating pipe provided on a wall of the gas flow path, and the calorific value adjusting means is a flow pipe for supplying a high-temperature fluid to the heating pipe. The flow control valve was provided so as to be adjustable.

In a fifth aspect of the present invention, the heating means is a heater provided on an outer peripheral surface of a wall of the gas flow path, and the heat amount adjusting means adjusts electric power supplied to the heater. There was a certain configuration.

[0010] In a sixth aspect of the present invention, a cooling water jacket for cooling the rotor chamber is provided around the rotor chamber in the casing of the compressor body, and before the oilless compressor starts to compress gas having a boiling point higher than room temperature. In the compressor body is filled with a gas having a boiling point lower than room temperature, so that the temperature difference between the casings does not exceed an allowable range, including the rotor chamber, at least in the casing where the gas flows, including the rotor chamber. The temperature of the flow path is gradually raised by a heating means, and after the temperature is raised, the gas in the compressor body is replaced with the gas having a boiling point higher than room temperature. After the compressor is started, the temperature difference of each part of the casing is within an allowable range. , The amount of heat from the heating means is reduced.

[0011]

According to the first to fifth aspects of the present invention, before starting the compressor, the boiling point of the gas flow path in the casing, including the rotor chamber, including at least the rotor chamber is lower than the normal temperature. Even if a high gas is filled, the gas in the compressor main body is vaporized after the temperature of the fluid from the high temperature fluid flow path and the heating means is increased, so that the compressor can be started while avoiding liquid compression. At the same time, when the temperature rises and falls, the non-uniformity of the temperature of the entire casing can be maintained within an allowable range.

Further, according to the sixth aspect of the present invention, almost no actual gas needs to be discharged when the compressor is started, and the temperature of the entire casing is made non-uniform when the temperature rises and falls. Will be able to keep

[0013]

Next, an embodiment of the present invention will be described with reference to the drawings. FIGS. 1 and 2 show an oilless screw compressor according to a first invention to which a starting method according to a sixth invention is applied,
A suction passage 1, a discharge passage 2, a compressor main body 3, a water supply passage 4, a drain passage 5, a bypass valve 6, and a bypass passage 7 similar to those of the oilless compressor shown in FIG. 6 are provided. The casing 11 of the compressor body 3 has a rotor chamber 13 having one opening at a suction port (not shown) and the other opening at a discharge port 12, and a pair of male and female screw rotors 14 meshing with each other in the rotor chamber 13. , 15 are rotatably housed. A cooling water jacket 16 for cooling the rotor chamber is provided around the rotor chamber 13. Water is supplied from the water supply passage 4 to the cooling water jacket 16 and discharged to the drain passage 5. It has become.

Further, in the present embodiment, a high-temperature fluid flow path 18 provided with a flow rate control valve 17 is provided so that high-temperature water or steam flows. Has been joined to. In the water supply channel 4 between the junction and the compressor body 3, the temperature of water in the water supply channel 4 is detected, and based on the detected temperature, the rate of change of the detected temperature with respect to time is determined. While avoiding exceeding the tolerance,
Before starting the compressor, the flow rate control valve 17 is operated to increase the fluid flow rate in the high-temperature fluid flow path 18 to raise the temperature of the flow path through which the compressed gas having a boiling point higher than room temperature passes. And a temperature controller 19 for reducing the fluid flow rate after the compressor is started.
Is formed.

Next, the starting method according to the sixth aspect of the invention will be described by applying to the oilless compressor having the above-described configuration. Before the compressor is started, the compressor body 3 is filled with a gas having a boiling point lower than room temperature, for example, air or N ₂ , and the flow control valve 1 is further filled.
7 is gradually opened, high-temperature water, preferably steam, is mixed with the cooling water in the water supply flow path 4, and the temperature of the water in the water supply flow path 4 is detected by the temperature controller 19, and the temperature difference of each part of the casing 11 is detected. Is increased so as not to exceed the allowable range. As described above, it is possible to prevent the temperature difference of each part of the casing 11 from exceeding the allowable range by, for example, the following. That is, the relationship between the rate of change of the opening degree of the flow control valve 17 and the variation in the temperature distribution of each part of the casing 11 is checked in advance, and the magnitude of this variation is within an allowable range, that is, the casing is determined by the temperature difference of each part. In order to fall within a range in which a trouble such as a crack of 11 does not occur, it is sufficient to check how much the rate of change of the opening degree of the flow control valve 17 can be maximized.

After the temperature of the flow path through which the gas to be compressed flows is raised as described above, the gas filled before the compressor is started is replaced with the gas to be compressed, and the compressor is started. Further, after starting the compressor, the temperature controller 19
Accordingly, the opening of the flow control valve 17 is gradually reduced. As described above, after the temperature of the flow path of the gas to be compressed is increased, the filled gas is replaced with the gas to be compressed, and then the compressor is started. Compressed gas loss is also reduced. In addition, by gradually changing the temperature of the gas flow path as described above, the temperature difference between each part of the casing 11 is reduced, and
The occurrence of problems such as cracks in the casing, non-uniform thermal expansion of the casing 11 due to abnormal variations in the temperatures of the above-described portions, and contact with the screw rotors 14, 15 and the inner peripheral surface of the rotor chamber 13 can be prevented. Driving can be done.

In this embodiment, the bypass passage 7 is used for reducing the load at the time of starting the compressor and adjusting the discharge pressure. That is, when the usage amount of the discharge gas decreases and the discharge pressure tends to abnormally increase, the bypass valve 6 is opened to return all or a part of the discharge gas to the suction passage 1.
Further, in order to adjust the flow rate of the high-temperature fluid from the high-temperature fluid flow path 18 to be mixed with the cooling water in the water supply flow path 4, instead of the flow rate control valve 17, as shown by a two-dot chain line in FIG. A well-known switching valve 20 for appropriately adjusting the ratio of the flow rate of the cooling water to the flow rate of the high-temperature fluid at the junction of the water supply flow path 4 and the high-temperature fluid flow path 18.
May be provided. Further, the position where the temperature controller 19 is arranged is not limited to the position in the above embodiment,
It may be a position where water can be detected in any part of the flow path of the water heated by the high-temperature fluid in the high-temperature fluid flow path 18 including the rotor chamber 13 or a wall of this flow path. For example, as shown in FIG. 2, a temperature controller 19 is provided on the inner peripheral surface of the wall of the rotor chamber 13, and an operation signal X based on the detected temperature of the inner peripheral portion of the wall is supplied to the flow control valve 17 or the switching valve. 20 and the same valve opening adjustment as described above may be performed. The flow control valve 17 and the switching valve 20 are
Since it has the function of adjusting the amount of heat given to the cooling water in the water supply passage 4, it is also a heat amount adjusting means.

FIG. 3 shows an oilless screw compressor according to a second invention to which a starting method according to another embodiment of the sixth invention is applied, which is common to the oilless compressor shown in FIGS. The same reference numerals are given to the same parts and the description is omitted. In the present embodiment, the heat exchanger 21 is provided in the water supply flow path 4, and the high-temperature fluid flow path 22 is provided through the heat exchanger 21 so that the temperature of the cooling water in the water supply flow path 4 can be raised. . Then, by the temperature controller 19 provided in the water supply flow path 4 on the outlet side of the heat exchanger 21, as in the case of the compressor shown in FIGS.
By adjusting the opening of the flow control valve 17, the same operation as described above is produced. Note that, also in the compressor shown in FIG. 3, the position of the temperature controller 19 is not limited to the water supply flow path 4 on the outlet side of the heat exchanger 21, as described above. The fluid flowing through the high-temperature fluid flow path 18 may be a high-temperature fluid, in addition to high-temperature water and steam, for example, the compressor body 3.
May be discharged gas.

FIG. 4 shows an oilless screw compressor according to the third and fourth inventions to which another embodiment of the sixth invention is applied.
The same parts as those in the compressor shown in FIGS. In the present embodiment, the heating tube 31 is embedded in the wall of the rotor chamber 13 and the temperature controller 19 is provided on the inner peripheral surface of the wall of the rotor chamber 13 to detect the temperature of the inner peripheral part of the wall. It is formed in. Also,
A flow path (not shown) for supplying and discharging the high-temperature fluid is connected to the heating pipe 31, and a flow rate control valve (not shown) for adjusting the flow rate of the high-temperature fluid is provided on the high-temperature fluid supply side. , 2 as in the case of the compressor shown in FIG.
It is formed so that the opening degree of this flow control valve is adjusted by the operation signal X from the control signal 9.

Then, while preventing the rate of change of the temperature detected by the temperature controller 19 with respect to time from exceeding an allowable value,
Before the compressor is started, the opening of the flow control valve is gradually increased by the operation signal X to increase the amount of heat applied to the wall. On the other hand, after the temperature of the rotor chamber is raised and after the compressor is started, the opening of the flow control valve is gradually increased by the operation signal X so that the change in the temperature detected by the temperature controller 19 becomes gentle as described above. , The amount of heat is reduced, and the same operation as that of the compressor shown in FIGS. It should be noted that a configuration for raising the temperature of the cooling water described above may be added to the above configuration. For example, as shown by a two-dot chain line in FIG.
A flow control valve 17 and a temperature controller 19 may be provided.

A flow control valve for controlling the flow rate of the high-temperature fluid supplied to the heating pipe 31 may be operated by the temperature controller 19 provided in the water supply flow path 4. Further, the fluid flowing through the heating pipe 31 may be a high-temperature fluid, such as high-temperature water,
In addition to the steam, for example, the gas discharged from the compressor body 3 may be used. FIG. 5 shows an oilless screw compressor according to third and fifth inventions to which another embodiment of the sixth invention is applied,
The same parts as those in the compressor shown in FIGS. In the present embodiment, the heater 41 is attached to the outer peripheral surface of the wall of the rotor chamber 13 and the temperature controller 19 is provided on the inner peripheral surface of the wall of the rotor chamber 13 to detect the temperature of the inner peripheral portion of the wall. It is formed so that. The heater 41 is also connected to a power source (not shown) via a power adjusting means (not shown). And
The power supplied to the heater 41 is adjusted by operating the power adjusting means according to the operation signal X from the temperature controller 19, and before the compressor is started, as in the case of the compressor shown in FIG. While the amount of heat given to the wall portion by the heater 41 is gradually increased, the amount of heat is gradually reduced after the temperature of the rotor chamber 13 is increased and after the compressor is started. A similar effect is produced.

Incidentally, a configuration for raising the temperature of the cooling water described above may be added to the above configuration. For example, in FIG.
As shown by the dashed line, the high-temperature fluid flow path 18 and the flow control valve 1
7, a temperature controller 19 and a heat exchanger 21 may be provided. Further, a power adjusting means for adjusting the electric power supplied to the heater 41 may be operated by the temperature adjuster 19 provided in the water supply flow path 4. Here, since the power adjusting means functions to adjust the amount of heat applied to the wall, it is also a heat amount adjusting means like the flow rate adjusting means 17. In addition,
In each of the above embodiments, the screw compressor has been described, but each of the above inventions is not limited to the screw compressor.

[0023]

As is apparent from the above description, according to the first invention, a cooling water jacket for cooling the rotor chamber is provided around the rotor chamber in the casing of the compressor body, and the gas having a boiling point higher than room temperature is provided. Oilless compressor that compresses
A high-temperature fluid flow path that is provided so as to be capable of heating the cooling water by being joined to a supply water flow path that supplies cooling water to the cooling water jacket; Including the cooling water jacket, the temperature of water at any point in the flow path of the water heated by the high-temperature fluid flow path and the temperature of at least one of the walls of the flow path are detected. Then, based on the detected temperature, while preventing the rate of change of the detected temperature with respect to time from exceeding an allowable value, operating the calorific value adjusting means to increase the caloric value before starting the compressor, and The temperature is increased by increasing the temperature of the flow path through which the gas passes, and a temperature controller is provided to reduce the heat amount after the temperature is increased and after the compressor is started.

According to the second aspect of the present invention, there is provided an oilless compressor having a cooling water jacket for cooling a rotor chamber around a rotor chamber in a casing of a compressor body and compressing a gas having a boiling point higher than room temperature. A high-temperature fluid channel provided to be capable of heating the cooling water via a heat exchanger provided in a water supply channel for supplying the cooling water to the cooling water jacket, and a flow rate provided to be capable of adjusting the fluid flow rate in the high-temperature fluid channel. A control valve, including the cooling water jacket, water in any location of the flow path of the water heated by the high temperature fluid flow path, and / or at least one of a wall portion of the flow path; Operating the flow rate control valve based on the detected temperature to prevent the rate of change of the detected temperature with respect to time from exceeding an allowable value, and operating the fluid flow rate before starting the compressor. Increase It raised a channel the gas passes, after heating, and after the compressor starts, is formed by providing a temperature controller for reducing the fluid flow rate.

Further, according to the third aspect of the present invention, there is provided an oilless compressor having a cooling water jacket for cooling the rotor chamber around the rotor chamber in a casing of the compressor body and compressing a gas having a boiling point higher than room temperature. A heating means for raising the temperature of at least the wall of the gas flow path in the casing through which the gas flows, including the rotor chamber; a heat quantity adjusting means for increasing or decreasing the amount of heat given to the wall by the heating means; The temperature of the wall is detected, and the calorie adjusting means is operated based on the detected temperature to prevent the rate of change of the detected temperature with respect to time from exceeding an allowable value. And a temperature controller for reducing the amount of heat after the temperature of the rotor chamber is increased and after the compressor is started.

Further, according to the fourth invention, the heating means is a heating pipe provided on a wall of the gas flow path, and the heat quantity adjusting means is a high-temperature fluid flow path for supplying a high-temperature fluid to the heating pipe. The flow control valve is provided so as to be capable of adjusting the flow rate.

Further, according to the fifth invention, the heating means is a heater provided on the outer peripheral surface of the wall of the gas flow path, and the heat amount adjusting means adjusts electric power supplied to the heater. It is a configuration that is a means.

Therefore, even before the compressor is started, even if the gas including the rotor chamber is filled with a gas having a boiling point higher than room temperature at least in a gas flow path in the casing through which the gas flows, the heating means After the temperature rise, the gas in the compressor body is vaporized, so that the compressor can be started without liquid compression, and the time required for gas replacement after starting the compressor can be shortened. The loss due to the discharge of the compressed gas can be greatly reduced. Also,
The difference in temperature between the above-mentioned portions of the casing at the time of raising and lowering the temperature is reduced, so that problems such as uneven thermal expansion of the casing and cracking of the casing can be prevented, and stable operation can be achieved.

Further, according to the sixth aspect of the present invention, there is provided an oilless compressor having a cooling water jacket for cooling the rotor chamber around the rotor chamber in a casing of the compressor body, and compressing a gas having a boiling point higher than room temperature. Before starting, at least the casing through which the gas flows, including the rotor chamber, is filled with a gas having a boiling point lower than room temperature in the compressor body so that the temperature difference between the casings does not exceed an allowable range. The temperature inside the compressor body is gradually increased by a heating means, and after the temperature is increased, the gas in the compressor body is replaced with the gas having a boiling point higher than room temperature. The amount of heat from the heating means was reduced so as not to exceed the allowable range.

Therefore, the time required for gas replacement in the gas flow path at the time of starting the compressor can be shortened, liquefaction of the gas to be compressed is eliminated, and loss due to discharge of the gas to be compressed is greatly reduced. Can be done. In addition, the temperature difference between the above-described portions of the casing at the time of raising and lowering the temperature is reduced, so that problems such as uneven thermal expansion of the casing and cracking of the casing can be prevented, and stable operation can be performed.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of an oilless screw compressor according to a first invention to which a starting method according to a sixth invention is applied.

FIG. 2 is a sectional view of a compressor body of the compressor shown in FIG.

FIG. 3 is an overall configuration diagram of an oilless screw compressor according to a second invention to which another embodiment of the sixth invention is applied.

FIG. 4 is a sectional view of a compressor body of an oilless screw compressor according to a third and a fourth invention to which another embodiment of the sixth invention is applied.

FIG. 5 is a cross-sectional view of a compressor body of an oilless screw compressor according to third and fifth inventions to which another embodiment of the sixth invention is applied.

FIG. 6 is an overall configuration diagram of a conventional oilless compressor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 3 Compressor main body 4 Water supply flow path 11 Casing 13 Rotor room 16 Cooling water jacket 17 Flow control valve 18 High temperature fluid flow path 19 Temperature controller 20 Switching valve 21 Heat exchanger 31 Heating pipe 41 Heater

Claims (6)

(57) [Claims] 1. A casing (11) of a compressor body (3).
A cooling water jacket (16) for cooling the rotor chamber (13) around the rotor chamber (13) inside the oil-free compressor for compressing a gas having a boiling point higher than room temperature; Water supply channel for supplying cooling water to the water (4)
High-temperature fluid flow path (1
8), heat amount adjusting means (17, 20) for adjusting the amount of heat given from the high temperature fluid flow path (18) to the cooling water, and the high temperature fluid flow path (18) including the cooling water jacket (16). Detecting the temperature of the water at any point in the flow path through which the heated water flows, and the temperature of at least one of the walls of the flow path, and performing the detection based on the detected temperature. While preventing the rate of change of the temperature with respect to time from exceeding an allowable value, the heat amount adjusting means (1)
7, 20) to increase the amount of heat and increase the temperature of the flow path (including 13) through which the gas passes before starting the compressor. After the temperature is increased and after starting the compressor, the amount of heat is increased. And a temperature controller (19) for reducing oil pressure. 2. A casing (11) of a compressor body (3).
A cooling water jacket (16) for cooling the rotor chamber (13) around the rotor chamber (13) inside the oil-free compressor for compressing a gas having a boiling point higher than room temperature; Water supply channel for supplying cooling water to the water (4)
A high-temperature fluid flow path (18) provided so as to be able to heat the cooling water via a heat exchanger (21) provided in the high-temperature fluid flow path (1).
8) A flow control valve (17) provided so as to be capable of adjusting a fluid flow rate
And water in any part of the flow path of the water heated by the high-temperature fluid flow path (18), including the cooling water jacket (16), and the wall of the flow path. At least one of the temperatures is detected, and the flow rate control valve (17) is operated based on the detected temperature to prevent the rate of change of the detected temperature with respect to time from exceeding an allowable value. A temperature controller (19) that increases the fluid flow rate before starting the machine and raises the temperature of the flow path (including 13) through which the gas passes, and decreases the fluid flow rate after the temperature rise and after the compressor starts. ), Wherein the oil-free compressor is formed. 3. A cooling water jacket (16) for cooling the rotor chamber (13) is provided around the rotor chamber (13) in the casing (3) of the compressor body, and a compressor for compressing gas having a boiling point higher than room temperature is provided. In the refueling compressor, the rotor chamber (1
A heating means for increasing the temperature of at least the wall of the gas flow path (including 13) in the casing through which the gas flows, including 3), and a calorie adjusting means for increasing or decreasing the amount of heat given to the wall by the heating means And detecting the temperature of the wall,
By operating the calorie adjusting means based on the detected temperature,
The heat quantity is increased before starting the compressor while avoiding the rate of change of the detected temperature with respect to time exceeding an allowable value, and the heat quantity is increased after the temperature of the rotor chamber (13) is increased and after the compressor is started. And a temperature controller (19) for reducing oil pressure. 4. The gas flow path (13), wherein the heating means comprises:
In the heating pipe (31) provided on the wall of (1), the heat amount adjusting means is provided with a flow control valve (1) provided so as to be capable of adjusting a flow rate in a high temperature fluid flow path (18) for supplying a high temperature fluid to the heating pipe (31).
The oilless compressor according to claim 4, wherein the compressor is (7). 5. The gas passage (13), wherein the heating means comprises:
The heater (41) provided on the outer peripheral surface of the wall portion, wherein the heat amount adjusting means is an electric power adjusting means for adjusting electric power supplied to the heater (41). Oiled compressor. 6. A casing (11) of a compressor body (3).
A cooling water jacket (16) for cooling the rotor chamber (13) is provided around the rotor chamber (13) therein, and before the start of the oilless compressor for compressing gas having a boiling point higher than room temperature, the compressor body ( 3) Fill the inside of the casing with a gas having a boiling point lower than room temperature, and at least allow the gas to flow, including the rotor chamber (13), so that the temperature difference of each part of the casing (11) does not exceed an allowable range. The flow path in the casing (11) is gradually heated by heating means (18, 21, 31, 41), and after the temperature is raised, the gas in the compressor body (3) is heated to a temperature higher than the normal temperature. After the compressor is started, the amount of heat from the heating means (18, 21, 31, 41) is reduced so that the temperature difference between the respective parts of the casing (11) does not exceed an allowable range. To start an oilless compressor.