JP2015105687A - Hydraulic pressure motor driving device and fuel gas supply device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To keep an entire amount and characteristics of water soluble hydraulic fluid for use in driving a hydraulic motor.SOLUTION: A hydraulic motor driving device 20 for use in driving a hydraulic motor 13 installed on a ship comprises a hydraulic oil reservoir tank 21 for storing water soluble hydraulic oil for driving the hydraulic motor 13; a hydraulic oil feeding tank 25 for storing water soluble hydraulic oil to be fed to the hydraulic oil reservoir tank 21; a feed water tank 27 for storing water to be fed to the hydraulic oil reservoir tank 21; a level gauge 23 for measuring a height of liquid surface in the hydraulic oil reservoir tank 21; a measuring instrument 22 for measuring characteristics of the water soluble hydraulic oil in the hydraulic oil reservoir tank 21; and a control part 40 for supplying water or water soluble hydraulic oil having moisture control adjusted from the hydraulic oil feeding tank 25 into the hydraulic oil reservoir tank 21 in response to a result of measurement of the measuring instrument 22 and a height of liquid surface in the hydraulic oil reservoir tank 21 measured by the level gauge 23.

Description

  The present invention relates to a hydraulic motor driving apparatus that drives a hydraulic motor mounted on a ship and a fuel gas supply apparatus that supplies fuel gas to a diesel engine mounted on the ship.

2. Description of the Related Art Conventional marine vessels use a two-stroke cycle low-speed diesel engine that can output at low speed and can be driven directly by a propeller.
In recent years, natural gas with low CO ₂ emission has attracted attention as a fuel for low-speed diesel engines. By injecting fuel into the combustion chamber of a low-speed diesel engine as a high-pressure gas and burning it, high output can be obtained with high thermal efficiency.

  In order to inject natural gas at a high pressure and inject it into the combustion chamber of a low-speed diesel engine, it is conceivable to increase the pressure of liquefied natural gas (hereinafter referred to as “LNG”) and then heat and vaporize it. Specifically, the LNG stored in the tank is boosted by a booster pump, and the boosted LNG is heated by a vaporizer and vaporized before being injected into a combustion chamber of a low-speed diesel engine (for example, Patent Document 1) .

  The line from the tank that stores LNG to the low-speed diesel engine through the booster pump, vaporizer, and the hazardous area (a gaseous explosive amount that requires special precautions for assembly, installation, and use of machinery). It is an area where an atmosphere exists or may exist, JIS C60079-10), and electrical equipment is required to be placed in a non-hazardous area as much as possible (JIS C60017-14). Therefore, it has been proposed to use a hydraulic motor to drive the booster pump and remotely operate the hydraulic motor from a non-hazardous area.

  When remotely operating a hydraulic motor in a hazardous area, it has been studied to use a flame-retardant water-soluble hydraulic oil to prevent fire due to oil leakage. The water-soluble hydraulic oil is a hydraulic oil containing water as a main component (JIS B0142: 2011).

JP 2012-177333 A

When the temperature of the water-soluble hydraulic oil rises during long-term voyages, the water evaporates and decreases. Therefore, it is necessary to periodically replenish the water-soluble hydraulic oil and maintain the total amount. Further, when the water content of the water-soluble hydraulic oil changes, the properties such as viscosity, pH, density, etc. of the water-soluble hydraulic oil change, and it becomes difficult to maintain the optimal characteristics for driving the hydraulic motor.
In order to solve the above-described problems, the present invention provides a hydraulic motor driving device capable of maintaining the total amount and properties of water-soluble hydraulic oil that drives the hydraulic motor, and a fuel gas supply device using the hydraulic motor driving device. Objective.

In order to solve the above problems, a first aspect of the present invention is a hydraulic motor drive device that drives a hydraulic motor mounted on a ship,
A hydraulic oil storage tank for storing an aqueous fluid that drives the hydraulic motor;
A hydraulic oil supply tank for storing water-soluble hydraulic oil for supplying to the hydraulic oil storage tank;
A water supply tank for storing water for replenishing the hydraulic oil storage tank;
A liquid level gauge for measuring the height of the liquid level in the hydraulic oil storage tank;
A measuring instrument for measuring the properties of water-soluble hydraulic oil in the hydraulic oil storage tank;
Control for supplying water or water-soluble hydraulic oil into the hydraulic oil storage tank according to the measurement result of the measuring device and the height of the liquid level in the hydraulic oil storage tank measured by the liquid level gauge And
It is characterized by providing.

  When the hydraulic oil storage tank is viewed from vertically above, the liquid level gauge is preferably disposed at the center position of the liquid level area of the hydraulic oil storage tank.

The controller is
When the height of the liquid level is lower than the lower limit height of the reference range, the amount of decrease in the height of the liquid level from the reference height within the reference range, and the measurement result of the measuring instrument Accordingly, it is preferable to adjust the water content and supply amount of the water-soluble hydraulic oil to be supplied into the hydraulic oil storage tank.

The controller is
When the height of the liquid level is higher than the upper limit height of the reference range, the amount of increase in the height of the liquid level from the reference height within the reference range, and the measurement result of the measuring instrument Accordingly, the calculated amount of water-soluble hydraulic oil is discharged from the hydraulic oil storage tank, and the water-soluble hydraulic oil is supplied into the hydraulic oil storage tank according to the discharge amount of the water-soluble hydraulic oil and the measurement result of the measuring instrument. It is preferable to adjust the water content and supply amount of the hydraulic fluid.

  When the water content of the water-soluble hydraulic oil in the hydraulic oil storage tank, which is calculated from the measurement result of the measuring instrument, is lower than a predetermined reference value, the control unit has water or water content. It is preferable to supply water-soluble hydraulic oil higher than a predetermined reference value into the hydraulic oil storage tank.

  When the water content of the water-soluble hydraulic oil in the hydraulic oil storage tank, which is calculated from the measurement result of the measuring device, is higher than a predetermined reference value, the control unit has a water content of the predetermined reference value. It is preferable to supply a lower water-soluble hydraulic oil into the hydraulic oil storage tank.

  The measuring device includes a viscometer that measures the viscosity of the water-soluble hydraulic oil in the hydraulic oil storage tank, a pH meter that measures the pH of the water-soluble hydraulic oil in the hydraulic oil storage tank, and the hydraulic oil storage tank The density is preferably selected from at least one density meter that measures the specific gravity of the water-soluble hydraulic oil.

The water-soluble hydraulic oil is different from water in at least one of viscosity, pH and specific gravity,
The measuring device preferably measures at least one of the viscosity, pH and specific gravity of the hydraulic oil.

  It is preferable to provide a temperature adjusting mechanism that keeps the temperature of the water-soluble hydraulic oil in the hydraulic oil storage tank constant.

Another aspect of the present invention is a fuel gas supply device that supplies fuel gas to a diesel engine mounted on a ship,
A liquid fuel tank for storing liquid fuel obtained by liquefying fuel gas;
The above hydraulic motor driving device;
A hydraulic motor driven by the hydraulic motor driving device;
A pump driven by the hydraulic motor and boosting the liquid fuel supplied from the liquid fuel tank;
A vaporizer for vaporizing the liquid fuel supplied by the pump and supplying it to the combustion chamber of a diesel engine;
It is characterized by providing.

  According to the present invention, the liquid level in the hydraulic oil storage tank that stores the water-soluble hydraulic oil that drives the hydraulic motor is measured by the liquid level gauge, and the operation is performed according to the measured liquid level. By replenishing the hydraulic oil storage tank with the water-soluble hydraulic oil stored in the oil supply tank, the entire amount of the water-soluble hydraulic oil can be maintained.

1 is a block diagram of a fuel gas supply device 10 according to an embodiment of the present invention. 4 is a flowchart showing a method for adjusting the liquid level in the hydraulic oil storage tank 21 by the control unit 40.

Hereinafter, a fuel gas supply apparatus according to a first embodiment of the present invention will be described with reference to FIGS.
The fuel gas supply device 10 of the present embodiment is a device that injects and supplies fuel gas, which is a vaporized liquid fuel, into the combustion chamber of the diesel engine 90 at a high pressure. The diesel engine 90 of this embodiment is a diesel engine mounted on a ship, and for example, a two-stroke cycle low-speed diesel engine can be used.

As shown in FIG. 1, the fuel gas supply device 10 includes a liquid fuel tank 11, a booster pump 12, a hydraulic motor 13, a vaporizer 14, a liquid fuel supply pipe 15, and a boosted fuel supply pipe. 16, a fuel gas supply pipe 17, a pressure regulating valve 18, and a hydraulic motor driving device 20. All these components of the fuel gas supply device 10 are mounted on a ship.
The liquid fuel tank 11 stores liquid fuel before the fuel gas supplied to the diesel engine 90 is vaporized. As the liquid fuel, liquefied natural gas (LNG), liquefied petroleum gas (LPG), or the like can be used. The liquid fuel tank 11 is connected to the liquid fuel supply pipe 15 and supplies the liquid fuel to the booster pump 12 through the liquid fuel supply pipe 15.

  The booster pump 12 has an inlet side connected to the liquid fuel supply pipe 15 and an outlet side connected to the boosted fuel supply pipe 16. The booster pump 12 boosts the liquid fuel supplied from the liquid fuel supply pipe 15 and supplies it to the carburetor 14 via the boosted fuel supply pipe 16. As the booster pump 12, a reciprocating pump (JIS B8311: 2002) in which a movable part (plunger or the like) reciprocates can be used.

The hydraulic motor 13 is a power source that drives the booster pump 12. For example, the rotational movement of the hydraulic motor 13 can be converted into the reciprocating movement of the plunger pump cylinder using a crank (not shown).
The hydraulic motor 13 is driven by a hydraulic motor driving device 20 described later.

The vaporizer 14 has an inlet side connected to the boosted fuel supply pipe 16 and an outlet side connected to the fuel gas supply pipe 17. The vaporizer 14 heats and vaporizes the pressurized liquid fuel supplied through the pressurized fuel supply pipe 16. As a heat source for heating the liquid fuel, for example, combustion heat of boil-off gas generated in the liquid fuel tank 11 can be used. For example, the liquid fuel may be heated by heat exchange with warm water heated by the combustion heat of boil-off gas.
The fuel gas supply pipe 17 is provided with a pressure regulating valve 18, one end of which is connected to the carburetor 14 and the other end is connected to the combustion chamber of the diesel engine 90. The fuel gas in which the liquid fuel is vaporized is regulated to a pressure within a predetermined range (for example, 150 to 300 bar) by the pressure regulating valve 18 and then supplied to the combustion chamber of the diesel engine 90 via the fuel gas supply pipe 17. .

  The hydraulic motor drive device 20 includes a hydraulic oil storage tank 21, a measuring instrument 22, a liquid level gauge 23, a hydraulic pump 24, a concentrated hydraulic oil supply tank 25, a concentrated hydraulic oil supply valve 26, and a water supply tank 27. The water supply valve 28, the discharge valve 29, the control unit 40, the hydraulic oil supply pipe 31, the hydraulic oil return pipe 32, the concentrated hydraulic oil supply pipe 33, the water supply pipe 34, the hydraulic oil supply pipe 35, A hydraulic oil discharge pipe 36.

  The hydraulic oil storage tank 21 stores hydraulic fluid that operates the hydraulic motor 13. As the hydraulic oil, an aqueous fluid can be used. The water-soluble hydraulic oil is a hydraulic oil containing water as a main component, and examples thereof include an O / W emulsion, a W / O emulsion, and a polyglycol solution. An O / W emulsion is a liquid in which small oil droplets are dispersed in a continuous phase of water. The W / O emulsion is a liquid in which small water droplets are dispersed in a petroleum-based hydraulic oil. The polyglycol solution is a hydraulic oil composed mainly of water and one or more types of glycol or polyglycol (JIS B0142: 2011).

  The measuring instrument 22 measures the properties of the water-soluble hydraulic oil in the hydraulic oil storage tank 21 and outputs a measurement signal to the control unit 40. Here, the properties of the hydraulic oil are, for example, viscosity, pH, specific gravity and the like. As the measuring device 22, a viscometer (as defined in JIS Z8803: 2011, a capillary viscometer, a falling ball viscometer, a coaxial double cylindrical rotational viscometer, a single cylindrical rotational viscometer, a cone-plate rotational viscometer, Vibration viscometer, etc.), pH meter (pH meter using a glass electrode as defined in JIS Z8802: 2011), density meter using a density bottle (Pycnometer) as defined in JIS Z8804: 2012, float A density meter using a hail, a vibration type density meter, a magnetic levitation type density meter, a density meter using a submerged weighing method, or the like can be used.

  The liquid level gauge 23 measures the liquid level of the water-soluble hydraulic oil in the hydraulic oil storage tank 21 and outputs a measurement signal to the control unit 40. The level gauge 23 is preferably arranged at the center position of the liquid level area of the hydraulic oil storage tank 21 when the hydraulic oil storage tank 21 is viewed from vertically above. Since the ship tilts or shakes due to the influence of the waves, the hydraulic oil storage tank 21 provided on the ship may not be arranged horizontally. The liquid level gauge 23 is arranged at the center position of the liquid level area of the hydraulic oil storage tank 21 so that the liquid level of the hydraulic oil storage tank 21 is measured even when the hydraulic oil storage tank 21 is tilted or shaken. It is possible to reduce the influence of waves when In addition, in the control part 40, the influence of the wave in a measurement signal can further be reduced by calculating the time average of a measurement signal.

  The hydraulic oil supply pipe 31 has one end provided in the hydraulic oil storage tank 21 and the other end connected to the hydraulic motor 13. The hydraulic pump 24 is provided in the hydraulic oil supply pipe 31. The hydraulic pump 24 supplies water-soluble hydraulic oil in the hydraulic oil storage tank 21 to the hydraulic motor 13 via the hydraulic oil supply pipe 31. As the hydraulic pump 24, a variable displacement pump driven by an electric motor (not shown) can be used. When the hydraulic pump 24 is a variable displacement type, the control unit 40 controls the electric motor that drives the hydraulic pump 24, thereby adjusting the amount of water-soluble hydraulic oil supplied to the hydraulic motor 13 and controlling the rotation of the hydraulic motor 13. can do. In addition, a constant capacity type pump may be used as the hydraulic pump 24 and a flow rate adjusting valve may be provided in the hydraulic oil supply pipe 31. In this case, the amount of water-soluble hydraulic oil supplied to the hydraulic motor 13 can be adjusted by controlling the flow rate adjustment valve by the control unit 40, and the rotation of the hydraulic motor 13 can be controlled.

  The hydraulic oil return pipe 32 has one end connected to the hydraulic motor 13 and the other end provided in the hydraulic oil storage tank 21. The hydraulic oil supplied from the hydraulic oil supply pipe 31 to the hydraulic motor 13 is returned to the hydraulic oil storage tank 21 via the hydraulic oil return pipe 32.

  The concentrated hydraulic oil tank 25 is a water-soluble hydraulic oil having a lower water content than the water-soluble hydraulic oil stored in the hydraulic oil storage tank 21 (preferably a component of a water-soluble hydraulic oil not containing water. Oil)). For example, if the water-soluble hydraulic oil is a polyglycol solution, the polyglycol solution having a lower water content than the water-soluble hydraulic oil, or a hydraulic oil that concentrates components other than water (such as glycol or polyglycol) in the water-soluble hydraulic oil May be stored in the concentrated hydraulic oil tank 25.

The concentrated hydraulic oil supply pipe 33 has one end connected to the concentrated hydraulic oil tank 25 and the other end connected to the water supply pipe 34 and the hydraulic oil supply pipe 35. The concentrated hydraulic oil in the concentrated hydraulic oil tank 25 is supplied to the hydraulic oil storage tank 21 via the concentrated hydraulic oil supply pipe 33 and the hydraulic oil supply pipe 35.
The concentrated hydraulic oil supply valve 26 is provided in the concentrated hydraulic oil supply pipe 33. The opening degree of the concentrated hydraulic oil supply valve 26 is controlled by the control unit 40 and adjusts the supply amount of the concentrated hydraulic oil from the concentrated hydraulic oil tank 25 via the concentrated hydraulic oil supply pipe 33.

The water supply tank 27 stores water to be supplied to the hydraulic oil storage tank 21 when the water in the water-soluble hydraulic oil decreases. Evaporation is mentioned as a factor which reduces the water in water-soluble hydraulic oil.
One end of the water supply pipe 34 is connected to the water supply tank 27, and the other end is connected to the concentrated hydraulic oil supply pipe 33 and the hydraulic oil supply pipe 35. The water in the water supply tank 27 is supplied to the hydraulic oil storage tank 21 through the water supply pipe 34 and the hydraulic oil supply pipe 35.

  One end of the hydraulic oil supply pipe 35 is provided in the hydraulic oil storage tank 21, and the other end of the hydraulic oil supply pipe 35 is connected to the concentrated hydraulic oil supply pipe 33 and the water supply pipe 34. The concentrated hydraulic oil supplied from the concentrated hydraulic oil supply pipe 33 and the water supplied from the water supply pipe 34 are mixed in the hydraulic oil supply pipe 33 and then supplied to the hydraulic oil storage tank 21. By adjusting the ratio of the opening of the concentrated hydraulic oil supply valve 26 and the water supply valve 28, the mixing ratio of the concentrated hydraulic oil and water in the water-soluble hydraulic oil supplied to the hydraulic oil storage tank 21 is adjusted. The content can be adjusted. Since the viscosity of the concentrated hydraulic oil is higher than that of water, the viscosity of the water-soluble hydraulic oil is adjusted by changing the mixing ratio of the concentrated hydraulic oil in the water-soluble hydraulic oil supplied to the hydraulic oil storage tank 21 and water. Can do.

The hydraulic oil discharge pipe 36 has one end provided in the hydraulic oil storage tank 21 and the other end connected to a drainage path (not shown). The water-soluble hydraulic oil in the hydraulic oil storage tank 21 is discharged to the drainage path via the hydraulic oil discharge pipe 36.
The discharge valve 29 is provided in the hydraulic oil discharge pipe 36. The opening degree of the discharge valve 29 is controlled by the control unit 40 to adjust the amount of hydraulic oil discharged from the hydraulic oil storage tank 21 via the hydraulic oil discharge pipe 36.

  The control unit 40 controls the hydraulic pump 24. Further, the control unit 40 adjusts the opening degrees of the concentrated hydraulic oil supply valve 26, the water supply valve 28, and the discharge valve 29 in accordance with measurement signals output from the measuring instrument 22 and the liquid level gauge 23.

A temperature adjustment mechanism that adjusts the temperature of the water-soluble hydraulic oil in the hydraulic oil storage tank 21 may be provided. For example, a thermometer 22T that measures the temperature of the water-soluble hydraulic oil in the hydraulic oil storage tank 21 and outputs a measurement signal to the control unit 40, for adjusting the temperature of the water-soluble hydraulic oil in the hydraulic oil storage tank 21 You may provide the heat exchange pipe 51, the pump 52 which supplies a refrigerant | coolant to the heat exchange pipe 51, valve | bulb 53A, 53B etc. which adjust the supply amount to the cooling pipe 51 of a refrigerant | coolant. As the refrigerant, for example, water or seawater can be used. The pump 52 and the valves 53A and 53B are controlled by the control unit 40. Depending on the temperature measured by the thermometer 22T, the control unit 40 may control the pump 52 and the valves 53A and 53B to adjust the supply amount of the refrigerant to the cooling pipe 51.
Further, instead of providing the heat exchange pipe 51 in the hydraulic oil storage tank 21, a heat exchanger (not shown) is provided in the hydraulic oil return pipe 32, and returns to the hydraulic oil storage tank 21 through the hydraulic oil return pipe 32. The water-soluble hydraulic oil may be cooled by a heat exchanger.

  In the present embodiment, when the liquid level is lower than the lower limit height of the reference range, the amount of decrease in the liquid level from the reference height within the reference range, and the measuring device 22 A water-soluble hydraulic oil whose water content is adjusted is supplied into the hydraulic oil storage tank 21 according to the measurement result.

Further, in this embodiment, when the liquid level is higher than the upper limit height of the reference range, the amount of increase in the liquid level from the reference height within the reference range, and the measuring instrument The discharge amount of the water-soluble hydraulic oil adjusted according to the measurement result of 22 is discharged from the hydraulic oil storage tank 21, and the supply amount and the water content of the water-soluble hydraulic oil adjusted according to the measurement result and the discharge amount are as follows. Is supplied into the hydraulic oil storage tank 21.
Here, by adjusting the opening degree of the concentrated hydraulic oil supply valve 26 and the water supply valve 28, the water content of the water-soluble hydraulic oil supplied into the hydraulic oil storage tank 21 can be adjusted. In the following description, a case where the concentrated hydraulic oil does not contain water will be described.

Hereinafter, a method of adjusting the liquid level in the hydraulic oil storage tank 21 by the control unit 40 will be described with reference to the flowchart of FIG.
First, the control unit 40 determines whether or not the liquid level is within a predetermined reference range, based on a liquid level measurement signal in the hydraulic oil storage tank 21 that is periodically input from the liquid level gauge 23. (Step S1). Here, the lower limit height of the reference range is defined as the amount of hydraulic oil that is sufficiently larger than the minimum amount required to operate the hydraulic motor 13 when the hydraulic oil is stored in the hydraulic oil storage tank 21. It is rank. The upper limit height of the reference range is higher than the lower limit height, and the hydraulic oil does not leak from the vent hole of the hydraulic oil storage tank 21 even if the hydraulic oil storage tank 21 is tilted or shaken by waves. The height is sufficiently low. The lower limit height and the upper limit height of the reference range can be arbitrarily set.
When the liquid level is within the predetermined reference range, the control unit 40 ends the process.

  When the liquid level is lower than the lower limit height of the reference range, the control unit 40 uses the measuring device 22 to measure the properties (viscosity, pH, specific gravity, etc.) of the water-soluble hydraulic oil in the hydraulic oil storage tank 21. (Step S2). Next, the control unit 40 calculates the supply amount of water-soluble hydraulic oil to the hydraulic oil storage tank 21 based on the amount of decrease from the liquid level reference height measured in step S1 (step S3).

  Next, based on the properties measured in step S2 and the supply amount of water-soluble hydraulic oil calculated in step S3, the supply amounts of concentrated hydraulic oil and water into the hydraulic oil storage tank 21 are calculated (step S4). The supply amounts of the concentrated hydraulic oil and water are calculated so that the properties of the water-soluble hydraulic oil in the hydraulic oil storage tank 21 after supply become the reference value. Here, the sum of the supply amount of the concentrated hydraulic oil and the supply amount of water is the supply amount of the water-soluble hydraulic oil calculated in step S3.

  For example, when the viscosity is measured by the measuring instrument 22, supply of concentrated hydraulic oil and water so that the water content of the water-soluble hydraulic oil is appropriate (so that the viscosity of the water-soluble hydraulic oil becomes a predetermined reference value). Calculate the quantity. The viscosity of the predetermined reference value is a viscosity of the water-soluble hydraulic oil at an appropriate water content at a predetermined temperature, and is an optimum viscosity for operating the hydraulic motor 13. Since the viscosity of the water-soluble hydraulic oil changes with temperature, the viscosity of the reference value is changed according to the temperature of the water-soluble hydraulic oil measured by the thermometer 22T (temperature compensation). In general, water-soluble hydraulic oil is higher than the viscosity of water, and the viscosity increases as the water content decreases.

  When water-soluble hydraulic oil whose viscosity increases as the water content decreases is used, if the measured viscosity is lower than the reference value, the water-soluble operation in the hydraulic oil storage tank 21 after supply is performed. Increase the supply amount of concentrated hydraulic oil (increase the ratio of concentrated hydraulic oil) so that the viscosity of the oil rises to the reference value. On the other hand, if the measured viscosity is higher than the reference value, the supply amount of water is increased so that the viscosity of the water-soluble hydraulic oil in the hydraulic oil storage tank 21 after supply decreases to the reference value (water Increase the ratio).

  In addition, when using water-soluble hydraulic oil (for example, W / O emulsion) whose viscosity decreases as the water content decreases, when the measured viscosity is lower than the reference value, The supply amount of water is increased (the water ratio is increased) so that the viscosity of the water-soluble hydraulic oil in the hydraulic oil storage tank 21 increases to the reference value. On the other hand, when the measured viscosity is higher than the reference value, the supply amount of the concentrated hydraulic oil is increased so that the viscosity of the water-soluble hydraulic oil in the hydraulic oil storage tank 21 after the supply decreases to the reference value ( Increase the ratio of concentrated hydraulic fluid).

  Further, when the pH is measured by the measuring instrument 22, supply of concentrated hydraulic oil and water so that the water content of the water-soluble hydraulic oil is appropriate (so that the pH of the water-soluble hydraulic oil becomes a predetermined reference value). Calculate the quantity. The pH of the predetermined reference value is the pH of the water-soluble hydraulic oil at an appropriate moisture content at a predetermined temperature, and is the optimum pH for operating the hydraulic motor 13. In general, the pH of water-soluble hydraulic oil is higher than that of water and increases as the water content decreases. Since the pH of the water-soluble hydraulic oil varies with temperature, the pH of the reference value is changed according to the temperature of the water-soluble hydraulic oil (temperature compensation).

  When water-soluble hydraulic oil whose pH increases as the water content decreases is used, if the measured pH is lower than the reference value, the water-soluble operation in the hydraulic oil storage tank 21 after supply is performed. Increase the supply amount of concentrated hydraulic oil (increase the ratio of concentrated hydraulic oil) so that the pH of the oil rises to the reference value. On the other hand, if the measured pH is higher than the reference value, the supply amount of water is increased so that the pH of the water-soluble hydraulic oil in the hydraulic oil storage tank 21 after supply is reduced to the reference value (water Increase the ratio).

  In the case of using water-soluble hydraulic oil whose pH decreases as the water content decreases, if the measured pH is lower than the reference value, the water solution in the hydraulic oil storage tank 21 after supply is supplied. Increase the amount of water supply (increase the water ratio) so that the pH of the hydraulic fluid rises to the reference value. On the other hand, when the measured pH is higher than the reference value, the supply amount of the concentrated hydraulic oil is increased so that the pH of the water-soluble hydraulic oil in the hydraulic oil storage tank 21 after the supply is lowered to the reference value ( Increase the ratio of concentrated hydraulic fluid).

  Further, when the density is measured by the measuring instrument 22, supply of concentrated hydraulic oil and water so that the water content of the water-soluble hydraulic oil is appropriate (so that the density of the water-soluble hydraulic oil becomes a predetermined reference value). Calculate the quantity. The density of the predetermined reference value is a density of the water-soluble hydraulic oil at an appropriate water content at a predetermined temperature, and is an optimum density for operating the hydraulic motor 13. In general, the density of water-soluble hydraulic oil is higher than that of water (specific gravity is greater than 1), and the density increases as the water content decreases (for example, a polyglycol solution).

  When water-soluble hydraulic oil whose density increases as the water content decreases is used, if the measured density is lower than the reference value, the water-soluble operation in the hydraulic oil storage tank 21 after supply is performed. Increase the supply amount of concentrated hydraulic oil (increase the ratio of concentrated hydraulic oil) so that the density of the oil rises to the reference value. On the other hand, if the measured density is higher than the reference value, the supply amount of water is increased so that the density of the water-soluble hydraulic oil in the hydraulic oil storage tank 21 after supply decreases to the reference value (water Increase the ratio).

  In the case of using water-soluble hydraulic oil whose density decreases as the water content decreases, if the measured density is lower than the reference value, the water solubility in the hydraulic oil storage tank 21 after supply is reduced. Increase the amount of water supply (increase the water ratio) so that the density of the hydraulic fluid increases to the reference value. On the other hand, when the measured density is higher than the reference value, the supply amount of the concentrated hydraulic oil is increased so that the density of the water-soluble hydraulic oil in the hydraulic oil storage tank 21 after the supply decreases to the reference value ( Increase the ratio of concentrated hydraulic fluid).

  In the case where the concentrated hydraulic oil contains water, the supply amount of the concentrated hydraulic oil and the supply amount of water may be appropriately adjusted according to the water content of the concentrated hydraulic oil.

Next, the control unit determines the opening and opening time of the concentrated hydraulic oil supply valve 26 and the water supply valve 28 based on the supply amounts of the concentrated hydraulic oil and water calculated in step S4 (step S5).
Next, the control unit 40 opens the concentrated hydraulic oil supply valve 26 and the water supply valve 28 at the opening determined in step S5 (step S6). Thereafter, after the opening time determined in step S5, the control unit 40 closes the concentrated hydraulic oil supply valve 26C and the water supply valve 28 (step S7), and ends the process.

  Possible causes for the liquid level in the hydraulic oil storage tank 21 to drop include, for example, liquid leakage from the hydraulic oil storage tank 21 and water evaporation. In addition, water may flow into the hydraulic oil storage tank 21 simultaneously with liquid leakage and water evaporation. For this reason, even when the liquid level in the hydraulic oil storage tank 21 is lowered, the water-soluble hydraulic oil whose water content is adjusted is replenished according to the liquid level and the properties of the hydraulic oil. The amount and properties of the water-soluble hydraulic oil in the hydraulic oil storage tank 21 can be kept constant.

  In step S1, when the liquid level is higher than the upper limit height of the reference range, the control unit 40 causes the measuring device 22 to change the properties (viscosity, pH, specific gravity, etc.) of the water-soluble hydraulic oil in the hydraulic oil storage tank 21. ) Is measured (step S8). Next, the control unit 40 discharges the water-soluble hydraulic oil from the hydraulic oil storage tank 21 based on the amount of increase from the reference level measured in step S1 and the property measured in step S8. Is calculated (step S9).

  Next, based on the property measured in step S8 and the discharge amount of the water-soluble hydraulic oil calculated in step S9, the supply amounts of concentrated hydraulic oil and water into the hydraulic oil storage tank 21 are calculated (step S410). The supply amount of the concentrated hydraulic oil and water is calculated so that the property of the water-soluble hydraulic oil in the hydraulic oil storage tank 21 after the supply becomes the reference value as in step S4. Here, the sum of the supply amount of the concentrated hydraulic oil and the supply amount of the water is the discharge amount of the water-soluble hydraulic oil calculated in step S9.

  Next, based on the discharge amount of the water-soluble hydraulic oil calculated in step S9 and the supply amount of the concentrated hydraulic oil and water calculated in step S10, the control unit 40 discharges the valve 29, the concentrated hydraulic oil supply valve 26, and the water supply valve. The opening degree and opening time of 28 are determined (step S11). Next, the control unit 40 opens the discharge valve 29 with the calculated opening degree (step S12), and closes the discharge valve 29 after the calculated opening time (step S13). Next, the control unit 40 opens the concentrated hydraulic oil supply valve 26 or the water supply valve 28 at the calculated opening degree (step S14), and closes the concentrated hydraulic oil supply valve 26 or the water supply valve 28 after the calculated opening time (step S14). S15), the process is terminated.

  As a cause of the liquid level in the hydraulic oil storage tank 21 rising, for example, inflow of water into the hydraulic oil storage tank 21 can be considered. Moreover, liquid leakage from the hydraulic oil storage tank 21 and water evaporation may occur simultaneously with the inflow of water into the hydraulic oil storage tank 21. For this reason, even when the liquid level in the hydraulic oil storage tank 21 is rising, the discharge of the hydraulic oil and the water content of the hydraulic oil whose water content is adjusted according to the properties of the liquid level and the hydraulic oil. By performing the replenishment, the amount and property of the water-soluble hydraulic oil in the hydraulic oil storage tank 21 can be kept constant.

Here, the calculation of the discharge amount of the water-soluble hydraulic fluid in step S9 and the calculation of the supply amounts of the concentrated hydraulic oil and water in step S10 can be performed by, for example, the following (a) to (c).
(A) based on the liquid level and Characteristics measured in step S8 in the hydraulic oil storage tank 21, the water content of the water-soluble hydraulic oil in the hydraulic oil storage tank 21 (the W ₁₎ and the content of the concentrate hydraulic oil (O ₁ ) can be calculated. When the water content in the water-soluble hydraulic oil in the hydraulic oil storage tank 21 at the reference level is W ₀ and the content of the concentrated hydraulic oil is O ₀ , the liquid level in the hydraulic oil storage tank 21 is the reference level. Since it is higher than the upper limit height of the range, W ₁ + O ₁ > W ₀ + O ₀ is established.

(B) When W ₁ > W ₀ , the operation is performed by setting (W ₁ −W ₀ ) / W ₁ of the total amount of the water-soluble hydraulic oil in the hydraulic oil storage tank 21 as the discharge amount of the water-soluble hydraulic oil. The water content in the water-soluble hydraulic oil in the oil storage tank 21 can be adjusted to be W ₀ . By setting the supply amount of the concentrated hydraulic oil to be the same as the discharge amount of the water-soluble hydraulic oil, the water-soluble hydraulic oil in the hydraulic oil storage tank 21 can be set to the reference viscosity at the reference level.

(C) On the other hand, when W ₁ ≦ W ₀ , O ₁ > O ₀ is established from W ₁ + O ₁ > W ₀ + O ₀ ≧ W ₁ + O ₀ . By setting (O ₁ -O ₀ ) / O ₁ of the total amount of the water-soluble hydraulic oil in the hydraulic oil storage tank 21 as the discharge amount of the water-soluble hydraulic oil, the water-soluble hydraulic oil in the hydraulic oil storage tank 21 is The concentration of the concentrated hydraulic oil can be adjusted to O ₀ . By making the supply amount of water the same as the discharge amount of the water-soluble hydraulic oil, the water-soluble hydraulic oil in the hydraulic oil storage tank 21 can be set to the reference viscosity at the reference level.
In the case where the concentrated hydraulic oil contains water, the discharge amount of the water-soluble hydraulic oil, the supply amount of the concentrated hydraulic oil, and the supply amount of water may be appropriately adjusted according to the water content of the concentrated hydraulic oil.

  As described above, the hydraulic oil is replenished, discharged, or supplied according to the liquid level in the hydraulic oil storage tank 21 and the properties (viscosity, pH, density, etc.) of the hydraulic oil, so The amount and properties of the water-soluble hydraulic oil can be kept constant.

In the above description, the case where the concentrated hydraulic oil does not contain water has been described. However, the present invention is not limited to this, and the water content is lower than that of the water-soluble hydraulic oil optimal for operating the hydraulic motor 13. Any water-soluble hydraulic oil can be used.
Further, in the present embodiment, the water content of the water-soluble hydraulic oil supplied to the hydraulic oil storage tank 21 based on the viscosity of the water-soluble hydraulic oil in the hydraulic oil storage tank 21 and the water solubility in the hydraulic oil storage tank 21. Although the case where the supply amount of the hydraulic oil and the discharge amount of the water-soluble hydraulic oil from the hydraulic oil storage tank 21 are calculated has been described, the present invention is not limited to this, and the density meter that measures the viscosity of the water-soluble hydraulic oil, pH An arbitrary measuring device may be selected from a pH meter that measures water and a density meter that measures density, and the water content of the water-soluble hydraulic oil supplied to the hydraulic oil storage tank 21 may be calculated based on the measurement result.

DESCRIPTION OF SYMBOLS 10 Fuel gas supply apparatus 11 Liquid fuel tank 12 Booster pump 13 Hydraulic motor
14 Vaporizer 15 Liquid fuel supply pipe 16 Boost fuel supply pipe 17 Fuel gas supply pipe 18 Pressure regulating valve 20 Hydraulic motor drive device 21 Hydraulic oil storage tank 22 Measuring instrument 23 Liquid level gauge 24 Hydraulic pump 25 Hydraulic oil supply tank 25C Concentrated hydraulic oil Tank 26 Hydraulic oil supply valve 26C Concentrated hydraulic oil supply valve 27 Discharge valve 28 Water supply tank 29 Water supply valve 31 Hydraulic oil supply pipe 32 Hydraulic oil return pipe 33 Concentrated hydraulic oil supply pipe 34 Water supply pipe 35 Hydraulic oil supply pipe 36 Hydraulic oil discharge pipe 40 Control Unit 51 Heat Exchange Pipe 52 Pump 53A, 53B Valve

Claims (10)

A hydraulic motor driving device for driving a hydraulic motor mounted on a ship,
A hydraulic oil storage tank for storing water-soluble hydraulic oil that drives the hydraulic motor;
A hydraulic oil supply tank for storing water-soluble hydraulic oil for supplying to the hydraulic oil storage tank;
A water supply tank for storing water for replenishing the hydraulic oil storage tank;
A liquid level gauge for measuring the height of the liquid level in the hydraulic oil storage tank;
A measuring instrument for measuring the properties of water-soluble hydraulic oil in the hydraulic oil storage tank;
The water solubility of the hydraulic oil storage tank is adjusted according to the measurement result of the measuring device and the height of the liquid level in the hydraulic oil storage tank measured by the liquid level gauge. A control unit for supplying hydraulic oil;
A hydraulic motor drive device comprising:   2. The hydraulic motor drive device according to claim 1, wherein when the hydraulic oil storage tank is viewed from vertically above, the liquid level gauge is disposed at a center position of a liquid level area of the hydraulic oil storage tank. The controller is
When the height of the liquid level is lower than the lower limit height of the reference range, the amount of decrease in the height of the liquid level from the reference height within the reference range, and the measurement result of the measuring instrument The hydraulic motor drive device according to claim 1 or 2, wherein the water content and the supply amount of the water-soluble hydraulic oil supplied into the hydraulic oil storage tank are adjusted accordingly. The controller is
When the height of the liquid level is higher than the upper limit height of the reference range, the amount of increase in the height of the liquid level from the reference height within the reference range, and the measurement result of the measuring instrument Accordingly, the calculated amount of water-soluble hydraulic oil is discharged from the hydraulic oil storage tank, and the water-soluble hydraulic oil is supplied into the hydraulic oil storage tank according to the discharge amount of the water-soluble hydraulic oil and the measurement result of the measuring instrument. The hydraulic motor drive device according to any one of claims 1 to 3, wherein the moisture content and supply amount of the hydraulic fluid are adjusted.   When the water content of the water-soluble hydraulic oil in the hydraulic oil storage tank, which is calculated from the measurement result of the measuring instrument, is lower than a predetermined reference value, the control unit has water or water content. The hydraulic motor drive device according to any one of claims 1 to 4, wherein water-soluble hydraulic oil higher than a predetermined reference value is supplied into the hydraulic oil storage tank.   When the water content of the water-soluble hydraulic oil in the hydraulic oil storage tank, which is calculated from the measurement result of the measuring device, is higher than a predetermined reference value, the control unit has a water content of the predetermined reference value. The hydraulic motor drive device according to any one of claims 1 to 5, wherein lower water-soluble hydraulic oil is supplied into the hydraulic oil storage tank.   The measuring device includes a viscometer that measures the viscosity of the water-soluble hydraulic oil in the hydraulic oil storage tank, a pH meter that measures the pH of the water-soluble hydraulic oil in the hydraulic oil storage tank, and the hydraulic oil storage tank The hydraulic motor drive device according to any one of claims 1 to 6, wherein the hydraulic motor drive device is selected from at least one of density meters that measure the specific gravity of the water-soluble hydraulic oil. The water-soluble hydraulic oil is different from water in at least one of viscosity, pH and specific gravity,
The hydraulic motor driving device according to any one of claims 1 to 7, wherein the measuring instrument measures at least one of viscosity, pH, and specific gravity of the hydraulic oil.   The hydraulic motor drive device according to any one of claims 1 to 8, further comprising a temperature adjustment mechanism that maintains a constant temperature of the water-soluble hydraulic oil in the hydraulic oil storage tank. A fuel gas supply device for supplying fuel gas to a diesel engine mounted on a ship,
A liquid fuel tank for storing liquid fuel obtained by liquefying fuel gas;
The hydraulic motor drive device according to any one of claims 1 to 9,
A hydraulic motor driven by the hydraulic motor driving device;
A pump driven by the hydraulic motor and boosting the liquid fuel supplied from the liquid fuel tank;
A vaporizer for vaporizing the liquid fuel supplied by the pump and supplying it to the combustion chamber of a diesel engine;
A fuel gas supply device comprising:

Images