KR20160035568A - A Treatment System of Gas - Google Patents

Abstract

The present invention relates to a gas treatment system. The gas treatment system comprises: boil off gas supply line connected from a liquefied gas storage tank to a place of demand and comprising a plurality of compressors compressing a boil off gas of the liquefied gas storage tank to be supplied to the place of demand; and a gas component analysis module measuring a heat quantity of the boil off gas. The compressor comprises: a first compression unit; and a second compression unit provided to a downstream of the first compression unit and enabling lubricating oil to be mixed into the boil off gas when the boil off gas is compressed. The gas component analysis module comprises: a fuel extraction line connected from the boil off gas supply line to a front end of the second compression unit; and a gas component analyzer connected to the fuel extraction line and measuring the heat quantity of the boil off gas.

Description

[0001] A Treatment System of Gas [0002]

The present invention relates to a gas treatment system.

A ship is a means of transporting large quantities of minerals, crude oil, natural gas, or several thousand containers. It is made of steel and buoyant to float on the water surface. The thrust generated by rotation of the propeller ≪ / RTI >

Such a ship generates thrust by driving a customer. At this time, the customer uses gasoline or diesel to move the piston, and the crankshaft is rotated by the reciprocating movement of the piston, so that the shaft connected to the crankshaft is rotated to drive the propeller It was common.

In recent years, however, LNG carriers have been used as fuel for LNG carriers that transport Liquefied Natural Gas (LNG). LNG carriers are used as fuel for LNG carriers, It is also applied to other ships.

Generally, it is known that LNG is a clean fuel and its reserves are more abundant than petroleum, and its usage is rapidly increasing as mining and transfer technology develops. This LNG is generally stored in a liquid state at a temperature of -162 ° C. or below under 1 atm. The volume of liquefied methane is about one sixth of the volume of methane in a gaseous state, The specific gravity is 0.42, which is about one half of that of crude oil.

However, the temperature and pressure required to drive demand can differ from the state of the LNG stored in the tank. Therefore, in recent years, research and development have been conducted on technologies for controlling the temperature and pressure of LNG stored in a liquid state and supplying it to customers.

In addition, when LNG is stored in a liquid state, some LNG is vaporized as boiling off gas (BOG) is generated due to heat penetration into the tank. In the past, in order to reduce the tank pressure, And simply discharged to the outside. In recent years, however, the necessity of development has been increasing for applications such as re-liquefaction of evaporation gas generated from the tank and supply to the customer.

It is an object of the present invention to provide a gas processing system for accurately grasping the amount of fuel supplied to an engine and controlling the speed of the engine as desired, .

It is also an object of the present invention to provide a method of controlling the flow rate of a lubricating oil by controlling the amount of lubricating oil to be mixed with the lubricating oil in the fourth or fifth compressor when the evaporating gas is compressed, And to assure the accuracy of the calorimetric measurement.

A gas processing system according to an aspect of the present invention includes an evaporation gas supply line connected to a customer from a liquefied gas storage tank and provided with a plurality of compressors for compressing the evaporated gas of the liquefied gas storage tank and supplying the condensed gas to the customer; And a gas component analysis module for measuring a calorific value of the evaporation gas, wherein the plurality of compressors comprise: a first compression section; a second compression section provided downstream of the first compression section, Wherein the gas component analysis module comprises: a fuel extraction line connected to a front end of the second compression unit in the evaporation gas supply line to extract the evaporation gas; And a gas component analyzer connected to the fuel extracting line and measuring a calorie of the evaporated gas.

Specifically, the gas component analysis module may further include a decompression unit that decompresses the evaporation gas extracted through the fuel extraction line.

Specifically, the gas component analysis module may further include a heating unit for heating the evaporation gas cooled by the reduced pressure.

Specifically, the first compression section may not cause the lubricating oil to be mixed with the evaporation gas during the evaporation gas compression.

A liquefied gas supply line connected to the liquefied gas storage tank and provided with a pump for pressurizing the liquefied gas; And a gas supply line to which the liquefied gas supply line and the evaporation gas supply line are joined and connected to the customer, and the fuel extraction line may be connected to the evaporation gas supply line.

The gas processing system according to the present invention can realize efficient operation considering the calorific value of the fuel when the speed of the engine is adjusted to adjust the speed of the ship.

Further, in consideration of the fact that the lubricating oil can be mixed in the compressor for compressing the evaporating gas, the gas treating system according to the present invention can measure the calorific value of the evaporating gas before the lubricating oil is mixed or remove the lubricating oil mixed in the evaporating gas By measuring the amount of heat of the evaporation gas, the amount of heat of the fuel can be grasped accurately.

1 is a conceptual diagram of a gas processing system according to an embodiment of the present invention.
2 is a conceptual diagram of a gas component analysis module of a gas processing system according to an embodiment of the present invention.
3 is a graph of adjusting the fuel quantity in a gas treatment system according to an embodiment of the present invention.
4 is a conceptual diagram of a gas processing system according to another embodiment of the present invention.
5 is a conceptual diagram of a gas component analysis module of a gas processing system according to another embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Hereinafter, the gas may be LPG, LNG, ethane, or the like, and may be, for example, LNG (Liquefied Natural Gas). In addition, the liquefied gas means LNG in liquid phase, and the evaporation gas can mean boil off gas (BOG) which is vaporized LNG.

Since the present invention can consume the liquefied gas and / or the evaporated gas at the places of demand such as the engine 100, the liquefied gas and the evaporated gas can be referred to as the fuel.

FIG. 1 is a conceptual diagram of a gas processing system according to an embodiment of the present invention, FIG. 2 is a conceptual diagram of a gas component analysis module of a gas processing system according to an embodiment of the present invention, In the gas treatment system according to the present invention.

1 to 3, a gas processing system 1 according to an embodiment of the present invention includes a liquefied gas storage tank 10, pumps 20 and 21, a heat exchanger 22, a compressor 30, A gas component analysis module 60, and a customer.

The liquefied gas storage tank 10 stores liquefied gas. The liquefied gas can be stored in a liquid state at about -160 degrees. The liquefied gas storage tank 10 can store the liquefied gas and / or the fuel, which is an evaporative gas, since the vaporized gas in which the liquefied gas is naturally vaporized can also be stored in the liquefied gas storage tank 10.

The pumps 20 and 21 supply the liquefied gas of the liquefied gas storage tank 10 to a customer. The pumps 20 and 21 may be constituted by a primary pump 20 and a secondary pump 21 and the primary pump 20 is connected to the inside of the liquefied gas storage tank 10 as booster pumps 20 and 21 And the liquefied gas can be pressurized to 1 to 25 bar to be delivered to the secondary pump 21.

The secondary pump 21 can pressurize the liquefied gas delivered from the primary pump 20 as a high pressure pump 20 or 21 at a high pressure. At this time, the secondary pump 21 can pressurize the liquefied gas to 200 to 400 bar, which is a demand pressure of a customer.

The heat exchanger 22 heats the liquefied gas pressurized at a high pressure to 10 to 50 degrees, which is the required temperature of the customer. At this time, the heat exchanger 22 can use the glycol water as a heat source, and the glycol water cooled by heat exchange with the liquefied gas can be heated by steam or the like and then recycled.

A liquefied gas supply line (23) is provided for delivering the liquefied gas stored in the liquefied gas storage tank (10) to a customer. The liquefied gas supplied to the liquefied gas supply line 23 is provided with pumps 20 and 21 and a heat exchanger 22. The liquefied gas of high temperature and high pressure passed through the pumps 20 and 21 and the heat exchanger 22 is supplied to the gas supply line 40, (Together with the evaporation gas) to the engine 100, which is the customer.

The compressor (30) compresses the evaporated gas of the liquefied gas storage tank (10). A plurality of compressors 30 may be provided to compress the evaporation gas into multiple stages, and the compressor 30 may compress the evaporation gas to 200 to 400 bar.

The compressor 30 may include a first compression unit 30a and a second compression unit 30b. When the compressor 30 is composed of five stages in total, the first compression section 30a means one stage to three stages, and the second compression stage 30b means four stages and five stages.

The second compression unit 30b compresses the relatively high-pressure evaporation gas to a higher pressure. At this time, the lubricating oil used in the cylinder inside the compressor 30 can be mixed with the evaporation gas. On the other hand, unlike the second compression section 30b, the first compression section 30a does not handle the high-pressure evaporation gas, so that the lubricating oil may not be mixed into the evaporation gas.

When the lubricating oil is mixed with the fuel, it may be a problem to measure the amount of heat of the fuel. As will be described later, the gas component analysis module 60 can measure the amount of heat of the fuel after removing the lubricating oil.

An evaporation gas supply line (31) is provided for transferring the evaporation gas stored in the liquefied gas storage tank (10) to a customer. A plurality of compressors 30 may be provided in series in the evaporation gas supply line 31. The evaporation gas compressed by the compressor 30 at a high pressure may be supplied to the engine 30 (Not shown).

The gas component analysis module 60 measures the amount of heat of the fuel. The greater the total amount of heat generated due to the consumption of the fuel, the greater the speed of the engine 100, which is a demanding engine. Therefore, in order to obtain the desired speed, the amount of heat of the fuel flowing into the engine 100 is determined, It is necessary to control it.

Therefore, in this embodiment, the gas component analysis module 60 may be provided upstream of the main engine 100 and may be provided in the gas supply line 40. [ Since the gas component analysis module 60 is expensive equipment costing more than 200 million units per unit, it is economically advantageous to reduce the number of units installed. The present embodiment can integrally measure the amount of heat of the fuel by installing the gas component analysis module 60 in the gas supply line 40 where the liquefied gas supply line 23 and the evaporation gas supply line 31 are joined . That is, the substance whose calorific value is measured by the gas component analysis module 60 may be fuel (liquefied gas and / or evaporated gas) supplied to the main engine 100.

The gas component analysis module 60 extracts the fuel through the fuel extraction line 61 connected to the evaporation gas supply line 31 (gas supply line 40) downstream of the plurality of compressors 30, can do. However, since the gas component analysis module 60 requires 1 to 10 bar of fuel in order to accurately measure the calorie amount, the gas component analysis module 60 may include the decompression portion 62. Since the fuel in the gas supply line 40 downstream of the plurality of compressors 30 has a pressure of 200 to 400 bar, the decompression unit 62 such as a pressure reducing valve can reduce the fuel to 1 to 10 bar.

At this time, the fuel is cooled by the Row Thompson effect. In order to increase the accuracy of the calorimetric measurement, the temperature of the fuel is preferably -10 to 20 degrees. Therefore, the gas component analysis module 60 further includes a heating unit 63.

The heating unit 63 may be a heating coil, and the temperature of the fuel can be increased to a temperature suitable for calorimetric measurement by compensating for the cooling of the fuel by the pressure reducing unit 62. [ Therefore, the fuel that has passed through the depressurizing portion 62 and the heating portion 63 has a temperature and a pressure suitable for calorimetric measurement.

The gas component analysis module 60 extracts the fuel from the plurality of compressors 30 through the fuel extraction line 61 to measure the amount of heat. The second compression unit 30b of the plurality of compressors 30 It is possible to cause the lubricant to be mixed into the evaporation gas during compression, and the lubricant may interfere with the calorimetry measurement.

Therefore, the gas component analysis module 60 is provided with the filter 64 for filtering out the lubricating oil, so that the amount of heat of the lubricating oil can be measured. At this time, the filter 64 may be provided upstream and / or downstream of the heating unit 63.

The fuel extracted through the fuel extraction line 61 of the gas component analysis module 60 is supplied to the gas component analyzer 65 after passing through the pressure reducing portion 62, the filter 64 and the heating portion 63 The calorie can be measured. At this time, the calorific value measured by the gas component analyzer 65 means the calorific value per unit flow rate.

The consumer consumes the liquefied gas and / or the evaporated gas to generate energy. In the present invention, the customer may be the engine 100, and the customer may be a main engine 100, which is an ME-GI engine consuming high-pressure fuel, an auxiliary engine 101 which is a heterogeneous fuel engine for power generation consuming low- . ≪ / RTI >

The liquefied gas supply line 23 and the evaporation gas supply line 31 may be joined to the gas supply line 40 at the front end of the main engine 100. [ That is, the gas supply line 40 may be supplied with a liquefied gas and / or an evaporated gas.

The gas supply line 40 may be provided with a gas control unit 102. The gas control unit 102 may correspond to a gas valve train (GVT) and may control the flow of fuel supplied to the main engine 100. For example, the gas control unit 102 controls whether or not the fuel is supplied, and additionally controls the supply flow rate of the fuel.

The main engine 100 may be provided in plural and the gas supply line 40 may be branched to each main engine 100 using the gas control unit 102 as a branch point. At this time, the gas component analysis module 60 may be provided upstream of the gas control unit 102 in the gas supply line 40.

The auxiliary engine 101 may be an engine that consumes relatively low pressure fuel relative to the main engine 100 and may be branch connected to the auxiliary engine 101. [ At this time, the branch point of the evaporation gas supply line 31 connected to the auxiliary engine 101 may be the second stage or the third stage downstream of the intermediate stage of the multi-stage compressor 30.

The gas composition analysis module 60 may be used to control the speed of the main engine 100 as desired. The main engine 100 may be an engine 100 that propels the propeller for propulsion of the ship, and the speed of the main engine 100 may be accelerated as the speed of the main engine 100 increases.

In order to increase the speed of the main engine 100, the total amount of fuel consumed in the main engine 100 must be increased. At this time, the total calorific value of the fuel can be estimated through the value obtained by multiplying the calorific value of the fuel measured by the gas component analysis module 60 by the flow rate of the fuel.

When the amount of heat measured by the gas component analysis module 60 is lowered, the flow rate of the fuel to be consumed in the main engine 100 can be increased. In this case, the decrease in the amount of heat may occur when the ratio of the evaporated gas in the fuel increases, because the evaporated gas having a high ratio of nitrogen to the liquefied gas has a relatively low calorific value per unit flow rate.

On the contrary, when the amount of heat measured by the gas component analysis module 60 is high, the flow rate of the fuel to be consumed in the main engine 100 can be reduced. This may be the case where the ratio of the liquefied gas to the evaporated gas in the fuel is increased.

That is, the gas component analysis module 60 can measure the calorific value of the fuel in which the evaporated gas and the liquefied gas are mixed, and estimate the ratio of the evaporated gas based on the measured calorie. Also, the flow rate of the fuel to be consumed in the main engine 100 can be derived according to the change of the heat quantity.

Especially, in case of laden voyage in which ships carry liquefied gas, the rate of evaporation gas in fuel is high because the amount of evaporation gas is relatively high. On the other hand, in the case of ballast voyage which is loaded with low liquefied gas, the rate of evaporated gas in the fuel is low because the amount of evaporated gas is not high. Therefore, calories in laden voyage can be lower than calories in ballast voyage.

Also, as the amount of the liquefied gas is reduced due to the consumption of fuel during the navigation, the rate of nitrogen gradually increases, so that the calorific value of the evaporated gas can be lowered. On the other hand, since the calorific value of the liquefied gas is maintained at a relatively constant value, the calorific value of the fuel in which the evaporated gas and the liquefied gas are mixed can be lowered as the voyage continues.

That is, the amount of heat of the fuel can be variously changed according to the navigation situation of the ship, so that the main engine 100 can control the consumption of fuel according to the variable amount of heat.

Specifically, if it is determined that the calorific value of the fuel measured by the gas component analysis module 60 is lowered, the main engine 100 can adjust the fuel supply valve to increase the flow rate of the fuel, thereby securing the total calorific value. This will be described in detail with reference to FIG.

Referring to FIG. 3, the main engine 100 can measure the amount of heat measured from the gas component analysis module 60, and increase the amount of fuel when it is determined that the amount of heat has decreased. At this time, the fuel amount is controlled by adjusting the fuel injection time. Instead of directly controlling the total time of fuel injection, the fuel injection time can be controlled by adjusting the rotation angle at which the fuel is injected.

The rotation angle may mean the rotation angle of the crankshaft connected to the piston and the connecting rod. The injection of fuel starts when the crankshaft is at 0 degree, that is, when the piston is located at the top dead center. Basically, the timing at which the fuel injection is stopped may be when the crankshaft is rotated 5 degrees.

However, if it is determined that the amount of heat of the fuel is lowered, the timing at which the fuel injection is stopped is delayed, and the fuel injection may be stopped when the crankshaft is rotated at 5 degrees or more.

However, since the rotation speed of the crankshaft is increased when the speed of the engine 100 is increased, the time required for the crankshaft to rotate from 0 to 5 degrees before increasing the speed of the engine 100, There may be no significant difference in the time the crankshaft rotates from 0 to 10 degrees. Therefore, if all of the other conditions are the same, if the fuel injection time is controlled according to the rotation angle of the crankshaft, the speed of the engine 100 becomes high and the rotation speed of the crankshaft becomes high, so that the fuel injection amount may not be sufficiently increased.

Therefore, the present embodiment can increase the injection pressure of the fuel when the speed of the engine 100 is increased. That is, when the rotational speed of the crankshaft is increased so that the time until the crankshaft reaches a certain rotational angle can not be sufficiently delayed, the main engine 100 can increase the fuel pressure and adjust the fuel injection amount.

That is, according to the amount of heat measured by the gas component analysis module 60, the main engine 100 adjusts the fuel injection time through the rotation angle of the crankshaft and adjusts the fuel injection pressure so that the total amount of heat is secured as desired . In particular, as described above, in the laden voyage, the ratio of the evaporative gas in the fuel to the ballast voyage is high and the amount of heat of the fuel can be low, so that the main engine 100 can increase the fuel injection time and the explosion pressure.

Of course, these controls may be implemented by a control unit (not shown) included in the main engine 100.

In view of the control of the main engine 100, the present invention may not use the flow meters 50a and 50b. Since the flow rate of the fuel supplied to the main engine 100 is actively controlled by the fuel injection valve of the main engine 100, the flow rate of the evaporated gas and / or the liquefied gas is measured by the flow meters 50a and 50b This is because the flow rate is not consumed by the main engine 100 at all.

That is, the main engine 100 determines the amount of heat according to the gas component analysis module 60, and controls the fuel injection time or pressure by adjusting the fuel injection valve accordingly, so that the flow rate of the fuel flowing into the main engine 100 is The main engine 100 can automatically grasp it.

Of course, the present invention may include a flow meter 50a for measuring the flow rate of the liquefied gas, a flow meter 50b for measuring the flow rate of the evaporative gas, etc. In this case, the total calorific value of the fuel before flowing into the main engine 100 is calculated . Just total calories can be used for reference only.

FIG. 4 is a conceptual view of a gas processing system according to another embodiment of the present invention, and FIG. 5 is a conceptual diagram of a gas component analysis module of a gas processing system according to another embodiment of the present invention.

Referring to FIGS. 4 and 5, in the gas processing system 1 according to another embodiment of the present invention, the installation position of the gas component analysis module 60 may be different from the embodiment.

The gas component analysis module 60 is configured to perform the gas component analysis on the basis of the difference between the upstream end of the second compression section 30b (between the first compression section 30a and the second compression section 30b or between the first and second compression sections 30a and 30b) Etc.) of the evaporation gas can be measured. The front end of the second compression portion 30b means a state before the lubricant is mixed.

That is, in this embodiment, the gas component analysis module 60 can extract the evaporated gas before the lubricant is mixed into the fuel extraction line 61, and can grasp the calorific value of the evaporated gas by the gas component analyzer 65.

In this embodiment, however, the calorific value of the liquefied gas can be omitted and only the calorific value of the evaporated gas can be measured. The amount of the evaporation gas can be varied depending on the flow rate of the liquefied gas in the liquefied gas storage tank 10, such as nitrogen. However, since the liquefied gas can be kept relatively constant, it is assumed that the calorific value of the liquefied gas is maintained at a constant value (constant range), and that the calorific value change of the fuel depends entirely on the caloric change of the evaporative gas. 100 can be controlled.

Further, in the gas component analysis module 60 of the present embodiment, the depressurization portion 62 can be omitted or reduced. The fuel extracted by the gas component analysis module 60 of one embodiment is 200 to 400 bar, but the fuel extracted by the gas component analysis module 60 of this embodiment may be 10 to 50 bar.

The fuel extraction line 61 of this embodiment is connected to the evaporation gas supply line 31 upstream of the second compression section 30b while the fuel extraction line 61 of the embodiment is connected to the second compression section 30b, The pressure of the evaporation gas (fuel) measured by the gas component analysis module 60 of the embodiment and the gas component analysis module 60 in this embodiment is lower than the pressure of the second compression The difference in compression ratio of the first and second compression units 30a and 30b may be different.

In addition, the gas component analysis module 60 of the present embodiment can omit or reduce the heating part 63 as the decompression part 62 is omitted or reduced, (64) may be omitted. That is, the size of the gas component analysis module 60 can be reduced in this embodiment.

1: Gas treatment system 10: Liquefied gas storage tank
20: primary pump 21: secondary pump
22: heat exchanger 23: liquefied gas supply line
30: compressor 30a: first compression unit
30b: second compression section 31: evaporation gas supply line
40: gas supply line 50a, 50b: flow meter
60: Gas component analysis module 61: Fuel extraction line
62: pressure reducing portion 63: heating portion
64: Filter 65: Gas component analyzer
100: main engine 101: auxiliary engine
102:

Claims (5)

An evaporation gas supply line connected to a customer from a liquefied gas storage tank and provided with a plurality of compressors for compressing the evaporated gas of the liquefied gas storage tank and supplying the condensed gas to the customer; And
And a gas component analyzing module for measuring a calorific value of the evaporated gas,
Wherein the plurality of compressors comprise:
And a second compression unit provided downstream of the first compression unit and generating mixing of lubricating oil with an evaporation gas during evaporation gas compression,
Wherein the gas component analysis module comprises:
A fuel extraction line connected to a front end of the second compression unit in the evaporation gas supply line to extract the evaporation gas; And
And a gas component analyzer connected to the fuel extracting line for measuring a calorific value of the evaporated gas. The gas analyzer according to claim 1,
Further comprising a depressurization portion for depressurizing the evaporation gas extracted through the fuel extraction line. The gas analyzer according to claim 2,
Further comprising a heating unit for heating the evaporation gas cooled by the decompression. 2. The apparatus according to claim 1,
And does not cause the mixing of the lubricating oil with the evaporating gas when the evaporating gas is compressed. The method according to claim 1,
A liquefied gas supply line connected to the liquefied gas storage tank and provided with a pump for pressurizing the liquefied gas; And
Further comprising a gas supply line which joins the liquefied gas supply line and the evaporation gas supply line and is connected to the customer,
Wherein the fuel extraction line is connected to the evaporation gas supply line.

Images