JP6595143B1 - Compressor unit and control method of compressor unit - Google Patents

Abstract

The present invention provides a technique for supplying a target gas with a target gas having a temperature within a temperature range desirable for the customer. The present application discloses a compressor unit which is installed in a ship and compresses a target gas which is a boil-off gas sucked from the LNG storage tank of the ship. The compressor unit cools the target gas discharged from one of the plurality of compression stages, a plurality of compression stages that sequentially increase the pressure of the target gas, a crank mechanism that drives pistons of the plurality of compression stages, and the plurality of compression stages. And a lead-out path for allowing the target gas cooled by the cooler to flow toward a generator or an internal combustion engine that is a demand destination, and a heat insulating material provided in the lead-out path. [Selection] Figure 1

Description

  The present invention relates to a compressor unit that compresses a target gas that is boil-off gas from an LNG storage tank of a ship, and a method for controlling the compressor unit.

  Conventionally, a compressor that boosts boil-off gas (hereinafter referred to as “target gas”) generated from LNG (Liquid Natural Gas) and supplies it to a demand destination such as an engine or a generator has been developed. (See Patent Documents 1 to 3).

Japanese Patent No. 6371930 Special table 2011-517749 gazette JP 2018-128039 A

  In order for a demand destination such as an engine or a generator to operate under desirable operating conditions, the temperature of the target gas supplied to the demand destination may be required to be within a predetermined temperature range. However, if the target gas is excessively dissipated in the air in the process of reaching the demand destination, the target gas may be supplied to the demand destination in a state where the temperature falls below the temperature range required by the demand destination.

  An object of this invention is to provide the technique which supplies the target gas which has the temperature in the temperature range desirable for a customer to a customer.

The compressor unit which concerns on one situation of this invention is installed in the ship, and is comprised so that the object gas which is the boil-off gas inhaled from the LNG storage tank of the said ship may be compressed. The compressor unit cools the target gas discharged from one of the plurality of compression stages, a plurality of compression stages for sequentially boosting the target gas, a crank mechanism for driving pistons of the plurality of compression stages, and the plurality of compression stages. And a lead-out path for flowing the target gas cooled by the cooler toward a generator or an internal combustion engine that is a demand destination, and a heat insulating material provided in the lead-out path. The cooler is provided in a stage connection channel for flowing the target gas from the one compression stage to the next compression stage. The lead-out path is a flow path branched from the stage connection flow path downstream of the cooler. The compressor unit further includes another heat insulating material provided in a portion from the cooler to the lead-out path in the stage connection channel.

  According to the above configuration, since the heat insulating material is provided in the lead-out path, heat dissipation from the target gas flowing from the cooler to the demand destination is suppressed, and the temperature of the target gas is in a temperature range preferable for the generator or the internal combustion engine. Maintained.

Since the lead-out path branches off from the stage connection flow path downstream of the cooler, the target gas cooled by the cooler flows into the lead-out path. Since a heat insulating material is provided in the lead-out path, further temperature decrease of the target gas flowing toward the demand destination through the lead-out path is suppressed. In addition to the lead-out path, a heat insulating material is also provided in a portion from the cooler to the lead-out path in the stage connection channel. Therefore, heat release from the target gas is also suppressed in the section from when the target gas flows into the lead-out path from the cooler.

The compressor unit which concerns on the other situation of this invention is installed in a ship, and is comprised so that the target gas which is the boil-off gas sucked from the LNG storage tank of the said ship may be compressed. The compressor unit includes a plurality of compression stages for sequentially boosting the target gas, a crank mechanism for driving pistons of the plurality of compression stages, and the target gas discharged from a final compression stage among the plurality of compression stages. A cooler that cools the gas, a lead-out path for flowing the target gas cooled by the cooler toward a generator or an internal combustion engine that is a demand destination, and a heat insulating material provided in the lead-out path .

According to the above configuration, since the heat insulating material is provided in the lead-out path, heat dissipation from the target gas flowing from the cooler to the demand destination is suppressed, and the temperature of the target gas is in a temperature range preferable for the generator or the internal combustion engine. Maintained.

  With regard to the above configuration, the length of the portion from the connection portion of the lead-out path to the next compression stage in the stage connection flow path may be longer than the length of the portion from the cooler to the connection portion of the lead-out path. Good.

  According to said structure, since the part from a cooler to a lead-out path becomes relatively short, the flow area of the object gas supplied to a demand destination through a lead-out path becomes short. As a result, heat dissipation from the target gas flowing to the demand destination is suppressed.

  With regard to the above configuration, the portion from the connecting portion of the lead-out path to the next compression stage in the stage connecting channel may be a non-insulating portion not having a heat insulating material.

  According to the above configuration, the target gas sucked into the next compression stage dissipates heat in the non-insulated portion. Since the temperature of the target gas is lowered on the suction side of the next compression stage, the temperature of the target gas desirable for the next compression stage is obtained.

  In the above-described method for controlling a compressor unit according to another aspect of the present invention, the cooler is provided on a cooling water passage through which cooling water for cooling the target gas flows, and on the cooling water passage, and the flow rate of the cooling water And an adjusting valve capable of adjusting the. The control method may include adjusting the opening of the adjustment valve so that the temperature of the target gas flowing out of the cooler is maintained within a certain range.

  According to the above configuration, the target gas is supplied to the demand destination in a state where heat dissipation from the target gas whose temperature is adjusted in the cooler is suppressed by the heat insulating material. Therefore, the temperature of the target gas is maintained in a temperature range preferable for the generator or the internal combustion engine.

  With regard to the above configuration, the compressor unit control method may adjust the opening of the adjustment valve so that the temperature of the target gas is maintained within a range of 30 ° C to 60 ° C.

  According to said structure, since heat dissipation from target gas is suppressed by a heat insulating material, the temperature of the target gas accommodated in the temperature range of 30 to 60 degreeC by adjustment of the opening degree of a regulating valve is the said temperature range. Supplied to customers with the temperature maintained.

  The above-described technology can supply a target gas with a target gas having a temperature within a temperature range desirable for the customer.

It is a schematic flowchart of the compressor unit of 1st Embodiment. It is a schematic flowchart of the cooler of a compressor unit. It is an expansion flow figure in the circumference of the lead-out path of a compressor unit. A schematic cross section of the lead-out path is shown. It is a schematic flowchart showing temperature control with respect to object gas. It is an expansion flow figure in the circumference of the lead-out path of the compressor unit of a 2nd embodiment. It is an expansion flow figure in the circumference of the lead-out path of the compressor unit of a 3rd embodiment.

  FIG. 1 is a schematic flowchart of the compressor unit 100 according to the first embodiment. The compressor unit 100 is described with reference to FIG.

  The compressor unit 100 is installed in a ship (not shown) having an LNG storage tank 101 in which LNG (Liquid Natural Gas) is stored. The compressor unit 100 is configured to suck in a target gas that is a boil-off gas generated in the LNG storage tank 101 and compress the sucked target gas. Specifically, the compressor unit 100 is configured to increase the pressure of the target gas to about 300 bar and supply the increased pressure to the predetermined demand destinations 102 and 103. With respect to the present embodiment, the customer 102 is an internal combustion engine. The customer 103 is a generator or an internal combustion engine. In the following description, the terms “upstream” and “downstream” are used based on the flow direction of the target gas.

  The compressor unit 100 includes a flow path 110 in which the target gas flows toward the demand destinations 102 and 103, a plurality of compression stages (first to fifth compression stages 201 to 205) for sequentially boosting the target gas, and a plurality of coolers. 281-284. The compressor unit 100 further includes a crank mechanism (not shown) used as a common drive source for the first to fifth compression stages 201 to 205. In FIG. 1, the compressor unit 100 is shown as an apparatus including the components shown in the two-dot chain line of FIG. 1.

  The upstream end of the flow path 110 is connected to the upper part of the LNG storage tank 101 so that the boil-off gas generated in the LNG storage tank 101 flows in. The downstream end of the flow path 110 is connected to a pipeline 104 extending from the customer 102.

  The flow path 110 includes a storage tank connection flow path 111, a stage connection flow path 113, a lead-out path 114, and a lead-out path 115.

  The storage tank connection channel 111 is connected to the LNG storage tank 101 and guides boil-off gas to the first compression stage 201 of the compressor unit 100. Since the compressor unit 100 includes the two first compression stages 201, the storage tank connection flow path 111 includes a main pipe 111C extending from the LNG storage tank 101, and branch portions 111A and 111B branched from the main pipe 111C. have. These branch portions 111A and 111B are connected to the first compression stage 201, respectively. That is, the two first compression stages 201 are connected to the two branch portions 111A and 111B so as to be parallel to each other. Note that the compressor unit 100 may have one first compression stage 201.

  The stage connection channel 113 connects the first to fifth compression stages 201 to 205 so that the target gas flows from one compression stage to the next compression stage. The upstream portion of the stage connection flow path 113 is branched portions 113A and 113B where the connection portion with the first compression stage 201 is branched in two. The other parts of the stage connection channel 113 are provided with second to fifth compression stages 202 to 205. The second to fifth compression stages 202 to 205 are arranged in series so as to sequentially increase the pressure of the target gas compressed by the first compression stage 201.

  The lead-out path 114 is a flow path that guides the target gas compressed in the final fifth compression stage 205 to the customer 102. The lead-out path 114 extends from the fifth compression stage 205 toward the customer 102. The lead-out path 115 is a flow path that guides the target gas compressed by the second compression stage 202 to the demand destination 103. The lead-out path 115 branches from a flow path section 119 a that connects the second compression stage 202 and the third compression stage 203 in the stage connection flow path 113, and is connected to a pipe line 105 that extends from the customer 103. . In addition, it is preferable that the heat insulating material is provided in the pipe line 105 over the full length.

  The diameters of the pistons and the inner diameters of the cylinder portions of the first to fourth compression stages 201 to 204 are smaller as the compression stage is downstream. The fifth compression stage 205 is smaller in the diameter of the piston and the inner diameter of the cylinder part than the first to fourth compression stages 201 to 204.

  The first to fifth compression stages 201 to 205 are driven by a common crank mechanism. The crank mechanism has a cross head connected to each piston rod of the first to fifth compression stages 201 to 205. The crank mechanism is configured to reciprocate the piston rod and the piston connected to the tip of the piston rod by changing the rotation of the crankshaft to the reciprocating motion of the crosshead.

  The coolers 281 to 284 are provided in the stage connection channel 113 and the outlet channel 114 in order to cool the target gas compressed by the second to fifth compression stages 202 to 205, respectively. The coolers 281 to 284 are configured to exchange heat between the target gas and cooling water (for example, seawater) having a temperature lower than that of the target gas. The cooling water is used for cooling the target gas. A schematic flow diagram of the cooler 281 is shown in FIG.

  The cooler 281 is disposed in the stage connection flow path 113 between the second compression stage 202 and the third compression stage 203. Specifically, the cooler 281 is attached to the stage connection flow path 113 in a flow path section 119a between the second compression stage 202 and the connection portion 119 of the outlet path 115 with respect to the stage connection flow path 113. The length of the pipe line extended between the cooler 281 and the connection part 119 of the lead-out path 115 to the stage connection flow path 113 is the pipe extended between the connection part 119 and the third compression stage 203. It is shorter than the length of the road.

  The cooler 281 is configured to exchange heat between the target gas and cooling water having a temperature lower than that of the target gas. For example, the cooler 281 includes a gas flow path 291 connected to the stage connection flow path 113 so that the target gas flows, a case 292 in which the gas flow path 291 is accommodated, and cooling water flowing into and out of the case 292. And a flowing cooling water flow path 293 may be included. In order to adjust the flow rate of the cooling water to the case 292, the cooler 281 further includes an adjustment valve 416 provided on the cooling water channel 293.

  The cooler 282 is disposed in the stage connection channel 113 between the third compression stage 203 and the fourth compression stage 204. The cooler 283 is disposed in the stage connection channel 113 between the fourth compression stage 204 and the fifth compression stage 205. The cooler 284 is disposed in the outlet path 114.

  These coolers 282 to 284 differ from the cooler 281 only in that they do not have the regulating valve 416. Therefore, the flow rate of the cooling water flowing through the cooler 281 can be adjusted using the adjustment valve 416, while the flow rate of the cooling water flowing through the coolers 282 to 284 is substantially constant. The coolers 282 to 284 may be configured to be able to adjust the flow rate of the cooling water, similarly to the cooler 281.

  The compressor unit 100 is configured to perform control for adjusting the pressure, flow rate, and temperature of the target gas supplied to the customers 102 and 103. The control-related parts used for these controls are described below.

  For the above-described adjustment control for the target gas, the compressor unit 100 includes a bypass line 411, a control valve 412, a pressure sensor 413, a control unit 414, and a temperature detection unit 415 (temperature sensor). Yes.

  The bypass line 411 branches from the stage connection flow path 113 in the flow path section 119b between the connection portion 119 of the lead-out path 115 to the stage connection flow path 113 and the third compression stage 203, and is connected to the storage tank connection flow path 111. ing. That is, the bypass line 411 is configured to return the target gas cooled by the cooler 281 to the suction side of the first compression stage 201 across the first compression stage 201 and the second compression stage 202.

  The control valve 412 is provided in the bypass line 411. The pressure sensor 413 and the temperature detection unit 415 are attached to the stage connection flow path 113 in a flow path section 119a between the connection portion 119 of the lead-out path 115 with respect to the stage connection flow path 113 and the cooler 281. The pressure sensor 413 is configured to detect the pressure of the target gas on the suction side of the third compression stage 203. The temperature detector 415 is configured to detect the temperature of the target gas that has flowed out of the cooler 281.

  The pressure sensor 413, the control valve 412, the adjustment valve 416, the temperature detection unit 415, and the cooler 281 are electrically connected to the control unit 414. The control unit 414 is configured to control the opening degrees of the control valve 412 and the regulating valve 416 based on the pressure and temperature detected by the pressure sensor 413 and the temperature detection unit 415, respectively. Specifically, the opening degree of the control valve 412 is adjusted by the control unit 414 so that a pressure desirable for the customer 103 is obtained. The opening degree of the regulating valve 416 is adjusted by the control unit 414 so that the temperature of the target gas flowing out from the cooler 281 is within a temperature range (for example, 30 ° C. to 60 ° C.) desirable for the demand destination 103. Note that the control unit 414 may be constructed as software or a dedicated circuit.

  The compressor unit 100 includes a heat insulating material 116 that covers the outer surface of the lead-out path 115 in order to supply the demand destination 103 with the temperature of the target gas adjusted by the control unit 414 substantially maintained. FIG. 3 is an enlarged flow diagram around the outlet path 115. FIG. 4 shows a schematic cross section of the lead-out path 115 covered with the heat insulating material 116. In FIG. 1, the heat insulating material 116 is shown as hatching on the lead-out path 115. The heat insulating material 116 entirely covers the outer surface of the outlet path 115. However, if the temperature of the target gas is maintained in the above-described temperature range, the heat insulating material 116 may only partially cover the outlet path 115. When fluid devices (valves or meters) are attached to the outlet path 115, these fluid devices may be exposed from the heat insulating material 116 or covered with the heat insulating material 116. . The heat insulating material 116 is formed using a heat insulating material such as glass wool or polyurethane.

  In the present embodiment, the stage connection flow path 113 that connects the second compression stage 202 and the third compression stage 203 is a non-insulated portion that is not provided with a heat insulating material. In the stage connection flow path 113 that connects the second compression stage 202 and the third compression stage 203, a flow path section 119 b that is a portion from the connection portion 119 of the lead-out path 115 to the third compression stage 203 in the stage connection flow path 113. The distance is longer than the length of the flow path section 119a, which is a portion from the cooler 281 to the connection portion 119 of the outlet path 115. That is, since the distance from the cooler 281 to the connection portion 119 is short, the target gas is guided to the outlet path 115 while its heat dissipation is suppressed as much as possible.

  The operation of the compressor unit 100 and the flow of the target gas will be described below with reference to FIGS. FIG. 5 is a schematic flowchart showing temperature control for the target gas by the control unit 414.

  When the compressor unit 100 is driven, suction and discharge of the target gas in the two compression chambers are alternately repeated in the first to fourth compression stages 201 to 204. In the fifth compression stage 205, the target gas is sucked and discharged in one compression chamber. The target gas discharged from the second to fifth compression stages 202 to 205 is cooled by passing through the coolers 281 to 284. A part of the target gas cooled by the cooler 281 is sequentially pressurized by the third to fifth compression stages 203 to 205 and supplied to the customer 102 or returned to the upstream side through the bypass line 411. The remaining target gas is supplied to the customer 103 through the outlet path 115.

  The pressure sensor 413 detects the pressure of the target gas flowing into the lead-out path 115 (that is, the suction pressure of the third compression stage 203) in order to supply the target gas having a desired pressure for the customer 103. The detected pressure data is output to the control unit 414. Based on the acquired pressure data, the control unit 414 controls the opening degree of the control valve 412 so that the pressure of the target gas flowing into the lead-out path 115 becomes substantially constant.

  In order to supply the target gas having a desired temperature for the customer 103, the temperature detection unit 415 detects the temperature of the target gas flowing into the outlet path 115. The detected temperature data is output to the control unit 414. Based on the temperature data, the control unit 414 determines whether or not the temperature of the target gas flowing out of the cooler 281 is within a certain range (step S110). The certain range used for the determination process is set so that the target gas having a temperature in a desirable temperature range for the customer 103 flows into the customer 103. For example, the certain range may be set to a range of 30 ° C to 60 ° C.

  If the temperature of the target gas is within a certain range, the control unit 414 maintains the opening degree of the adjustment valve 416 (step S120). If the temperature of the target gas exceeds the upper limit threshold of a certain range (step S110: upper), the opening degree of the regulating valve 416 is increased (step S130). As a result, the flow rate of the cooling water increases, and the temperature of the target gas flowing out of the cooler 281 decreases. The processing loop of steps S110 and S130 is continued until the temperature of the target gas falls within a certain range. If the temperature of the target gas is below the lower limit threshold of a certain range (step S110: lower), the opening degree of the adjustment valve 416 is decreased (step S140). As a result, the flow rate of the cooling water decreases and the temperature of the target gas flowing out of the cooler 281 increases. The processing loop of steps S110 and S140 is continued until the temperature of the target gas falls within a certain range.

  Through the control shown in FIG. 5, the temperature of the target gas flowing out of the cooler 281 becomes a value within the temperature range (30 ° C. to 60 ° C.) desirable for the customer 103. Part of the target gas flowing out of the cooler 281 is sucked into the third compression stage 203 or returned upstream through the bypass line 411, while the remaining target gas is supplied to the customer 103 through the outlet path 115. Is done. Since the lead-out path 115 is covered with the heat insulating material 116, the heat of the target gas flowing through the lead-out path 115 is suppressed from being released to the atmosphere. Therefore, the target gas is supplied to the customer 103 while maintaining a temperature in a temperature range desirable for the customer 103. Since the influence of the change in the outside air temperature on the temperature of the target gas supplied to the customer 103 is reduced by the heat insulating material 116, the change in the outside air temperature is controlled in the flow rate control of the cooling water described with reference to FIG. It does not have to be considered.

  The length of the pipe line extended between the cooler 281 and the connection part 119 of the lead-out path 115 to the stage connection flow path 113 is the pipe extended between the connection part 119 and the third compression stage 203. It is shorter than the length of the road. Therefore, the amount of heat released from the target gas in the flow path section 119a between the cooler 281 and the connection portion 119 of the outlet path 115 to the stage connection flow path 113 is reduced. Even if there is atmospheric heat dissipation from the target gas in the flow path section 119a, the temperature drop of the target gas is slight. That is, the possibility that the target gas is supplied to the customer 103 at a temperature lower than the lower limit (30 ° C.) of the desirable temperature range is low.

  On the other hand, since the flow path section 119b from the connection portion 119 of the lead-out path 115 to the stage connection flow path 113 to the third compression stage 203 is relatively long, the heat radiation from the target gas in the flow path section 119b is relatively large. Become. That is, the temperature of the target gas drops in this flow path section 119b. Therefore, the temperature of the target gas sucked into the third compression stage 203 is prevented from becoming excessively high.

  FIG. 6 is a diagram illustrating a part of the compressor unit 100 according to the second embodiment. In the stage connection flow path 113, another heat insulating material 117 is added to the flow path section 119a between the cooler 281 and the connection portion 119 of the lead-out path 115 in order to further suppress heat dissipation. The heat insulating material 117 covers the flow path section 119a over the entire length. However, if the temperature of the target gas is maintained within a certain temperature range, the heat insulating material 117 may only partially cover the flow path section 119a. When fluid devices (valves or meters) are attached to the flow path section 119a, these fluid devices may be exposed from the heat insulating material 116 or covered with the heat insulating material 116. Also good. The heat insulating material 117 may be the same material as the heat insulating material 116 or may be a different material. A flow passage section 119b from the connection portion 119 of the lead-out passage 115 to the third compression stage 203 in the stage connection flow passage 113 is left as a non-heat insulating portion where no heat insulating material is provided. The distance of the flow path section 119b is longer than the length of the flow path section 119a between the cooler 281 and the connection portion 119.

  Since the heat insulating material 117 is provided, the heat radiation from the target gas is also suppressed in the flow path section 119a between the cooler 281 and the connection portion 119 of the outlet path 115 with respect to the stage connection flow path 113. Heat dissipation from the target gas flowing into the lead-out path 115 is suppressed by the heat insulating material 116. As a result, the target gas is supplied to the customer 103 while maintaining the temperature adjusted by the cooler 281 so as to be within a desirable temperature range for the customer 103. Since the influence of the change in the outside air temperature on the temperature of the target gas supplied to the customer 103 is reduced by the heat insulating materials 116 and 117, the outside air temperature is controlled in the flow rate control of the cooling water described with reference to FIG. Variations need not be considered.

  On the other hand, the flow path section 119b between the connection portion 119 of the lead-out path 115 and the third compression stage 203 with respect to the stage connection flow path 113 is a non-heat-insulating part in which no heat insulating material is provided, so Heat release from the target gas is positively allowed. Since the length of the non-adiabatic portion is relatively long, the amount of heat released from the target gas increases. Therefore, the temperature of the target gas sucked into the third compression stage 203 is prevented from becoming excessively high.

  FIG. 7 is a diagram illustrating a part of the compressor unit 100 according to the third embodiment. The above heat insulation technology is applied to the target gas supplied to the customer 103. However, the same heat insulation technology may be applied to the target gas supplied to the customer 102. As shown in FIG. 7 (enlarged flow diagram around the outlet path 114), the outlet path 114 extending from the cooler 284 toward the customer 102 may be entirely or partially covered by the heat insulating material 118. When fluid devices (valves or gauges) are attached to the outlet path 114, these fluid devices may be exposed from the heat insulating material 116 or covered with the heat insulating material 116. The heat insulating material 118 may be the same material as the heat insulating material 116 or may be a different material. In this case, heat release from the target gas while the target gas flows through the outlet path 114 is suppressed. Therefore, the target gas is supplied to the customer 102 while substantially maintaining the temperature lowered by the cooler 284.

  If it is guaranteed that the temperature of the target gas flowing out of the cooler 284 falls within the temperature range desirable for the customer 102, the cooler 284 may not be controlled by the control unit 414. However, the control technology applied to the cooler 281 may be applied to the cooler 284 in order to prevent the temperature of the target gas flowing out from the cooler 284 from deviating from the temperature range desired for the demand destination 102. . In this case, another temperature detection unit (not shown) for detecting the temperature of the target gas flowing out from the cooler 284 may be added. The control unit 414 may adjust the flow rate of the cooling water used for heat exchange in the cooler 284 based on the temperature detected by the additional temperature detection unit.

  It should be understood that the embodiments disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  Regarding the above-described embodiment, the opening degree of the adjustment valve 416 is automatically adjusted by the control unit 414 based on the temperature detected by the temperature detection unit 415. However, the opening degree of the regulating valve 416 may not be automatically adjusted. For example, the opening degree of the regulating valve 416 may be determined through a preliminary test so that a temperature within a temperature range desirable for the customer 103 can be obtained. Alternatively, if the temperature detected by the temperature detection unit 415 is displayed to the user, the user may adjust the opening of the adjustment valve 416 by looking at the displayed temperature (that is, manual adjustment). ). In these cases, the opening degree control of the regulating valve 416 described with reference to FIG. 5 is unnecessary.

  In FIG. 6, when the influence on the third compression stage 203 can be ignored, a heat insulating portion is provided in the flow passage section 119 b from the connection portion 119 of the outlet passage 115 in the stage connection flow passage 113 to the third compression stage 203. May be.

  For the embodiment described above, five compression stages are used. However, how many compression stages are provided may be determined based on the pressure of the target gas required by the customer. Therefore, for example, a four-stage type or a six-stage type compression stage may be used as the compression stage.

  Regarding the above-described embodiment, the target gas compressed in the second compression stage 202 is supplied to the customer 103. However, the target gas compressed in another compression stage may be supplied to the customer 103. Even in this case, the heat insulating material is provided in the outlet path that flows toward the customer 103.

  The technique of the above-described embodiment is suitably used for a compressor unit mounted on a ship.

100 ... Compressor unit 101 ... LNG storage tank 102 ... ... Destination 103 ······························································· stage connection flow path 114, 115 ························································································· stage)
281, 284 ... Cooler 293 ... Cooling water flow path 416 ... tuning valve

Claims (6)

A compressor unit that is installed in a ship and compresses a target gas that is boil-off gas sucked from the LNG storage tank of the ship,
A plurality of compression stages for sequentially boosting the target gas;
A crank mechanism for driving pistons of the plurality of compression stages;
A cooler for cooling the target gas discharged from one of the plurality of compression stages;
A lead-out path for flowing the target gas cooled by the cooler toward a generator or an internal combustion engine that is a demand destination;
A heat insulating material provided in the lead-out path ,
The cooler is provided in a stage connection channel for flowing the target gas from the one compression stage to the next compression stage,
The lead-out path is a flow path branched from the stage connection flow path downstream of the cooler,
The compressor unit further includes another heat insulating material provided in a portion from the cooler to the lead-out path in the stage connection channel . A compressor unit that is installed in a ship and compresses a target gas that is a boil-off gas sucked from the LNG storage tank of the ship,
A plurality of compression stages for sequentially boosting the target gas;
A crank mechanism for driving pistons of the plurality of compression stages;
A cooler for cooling the target gas discharged from the final compression stage among the plurality of compression stages;
A lead-out path for flowing the target gas cooled by the cooler toward a generator or an internal combustion engine that is a demand destination;
And a heat insulating material provided in the outlet path . The length of the portion extending from the connecting portion of the outlet passage at stage connection channel to the next compression stage is longer than the length of the portion extending in the connecting portion of the outlet passage from the cooler, according to claim 1 Compressor unit. 4. The compressor unit according to claim 3 , wherein the portion from the connection portion of the lead-out path in the stage connection flow path to the next compression stage is a non-heat insulating portion having no heat insulating material. A method for controlling a compressor unit according to any one of claims 1 to 4 ,
The cooler is
A cooling water flow path through which cooling water for cooling the target gas flows;
An adjustment valve provided on the cooling water flow path and capable of adjusting a flow rate of the cooling water;
With
The said control method is a control method of the compressor unit including adjusting the opening degree of the said adjustment valve so that the temperature of the said target gas which flowed out from the said cooler may be maintained in a fixed range. A method for controlling a compressor unit according to claim 5 ,
A method for controlling a compressor unit, wherein the opening of the adjustment valve is adjusted so that the temperature of the target gas is maintained within a range of 30C to 60C.

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