Frictional resistance reduction device for ship
A inject gas control device that performs, for example, control reflecting variation in vessel velocity over time without adversely affecting the main engine is realized. That is, it is prevented that gas is drawn too much and thereby a gas supply or charged air rate becomes insufficient, efficiency of the main engine is decreased and exhaust gas is deteriorated, and analogous events occur because the gas supply or charged air rate is too much instead. There are provided a main engine 4010 acquiring propelling power for a vessel 1 , and a turbocharger 4011 that is driven by exhaust gas from the main engine 4010 and blows pressurized gas to the main engine 4010 . A part of the pressurized gas and/or exhaust gas is drawn from between the turbocharger 4011 and the main engine 4010 ( 5023, 5024 and 5025 ). The drawn pressurized gas and/or exhaust gas are injected in the proximity 9 of the hull on or below the waterline ( 5040 ), and the drawing rate of the pressurized gas and/or the exhaust gas is controlled on the basis of a physical quantity related to a heat load on the main engine 10 and characteristics of the turbocharger ( 4200 ).
1. A frictional resistance reduction device for a vessel, comprising:
a main engine of the vessel;
a turbocharger that is driven by exhaust gas of the main engine and blowing supplies pressurized gas to the main engine;
an adjustment valve, which adjusts a mass flow rate of the pressurized gas and/or exhaust gas to be drawn from between the turbocharger and the main engine;
a gas outlet, which injects the drawn pressurized gas and/or exhaust gas at least to a bottom of the vessel on or below a waterline via a path;
a scavenging gas pressure sensor, which detects a scavenging gas pressure;
an exhaust gas temperature sensor, which detects an exhaust gas temperature; and
a control device, which controls the mass flow rate of the pressurized gas and/or exhaust gas to be drawn, by using the adjustment valve, on the basis of the scavenging gas pressure detected by the scavenging gas pressure sensor and the exhaust gas temperature detected by the exhaust gas temperature sensor,
wherein when pressure of the pressurized gas and/or the exhaust gas is equal to or more than the pressure at draft, supplying of the pressurized gas and/or the exhaust gas to the gas outlet is started, and when the pressure of the pressurized gas and/or the exhaust gas is equal to or less than the pressure at the draft, supplying of the pressurized gas and/or the exhaust gas to the gas outlet is stopped.
2. The frictional resistance reduction device for a vessel according to claim 1 , further comprising a variable nozzle, which maintains gas supply characteristics of the turbocharger, wherein the variable nozzle is controlled according to the mass flow rate of the pressurized gas and/or the exhaust gas to be drawn, a physical quantity related to a heat load on the main engine, and the characteristics of the turbocharger.
3. The frictional resistance reduction device for a vessel according to claim 1 , further including a navigational condition detection means, wherein the navigational condition detection means is a relative velocity detector, which detects a relative velocity between a hull and water, and the number of gas outlets and/or an inject rate of gas is increased or decreased according to increase and decrease of the relative velocity.
4. The frictional resistance reduction device for a vessel according to claim 1 , further comprising a navigational condition detection means, wherein the navigational condition detection means is a draft detector, which detects a draft of the vessel, and the number of gas outlets and/or an inject rate of gas are increased or decreased according to the draft.
5. The frictional resistance reduction device for a vessel according to claim 1 , further comprising a navigational condition detection means, wherein the navigational condition detection means is an inclination detector which detects an inclination of a hull, and the number of gas outlets laterally provided at the vessel and/or an inject rate of gas is controlled.
6. The frictional resistance reduction device for a vessel according to claim 3 , wherein the gas outlet is provided on the bottom of the vessel, and the relative velocity detector is provided on a side of the vessel.
7. The frictional resistance reduction device for a vessel according to claim 1 , wherein the path runs on or above the waterline and is then connected to the gas outlet.
8. The frictional resistance reduction device for a vessel according to claim 1 , wherein the path is blocked by an open/close valve in the proximity of the gas outlet when injecting of the pressurized gas and/or exhaust gas is stopped.
9. A frictional resistance reduction device for a vessel, comprising:
a main engine of the vessel;
a turbocharger that is driven by exhaust gas of the main engine and blowing pressurized gas to the main engine;
an adjustment valve, which adjusts a mass flow rate of the pressurized gas and/or exhaust gas to be drawn from between the turbocharger and the main engine;
a sensor that detects the mass flow rate of the pressurized gas and/or exhaust gas to be drawn from between the turbocharger and the main engine;
a gas outlet, which injects the drawn pressurized gas and/or exhaust gas at least to a bottom of the vessel on or below a waterline via a path;
a control device, which causes the adjustment valve to control the mass flow rate of the pressurized gas and/or exhaust gas to be drawn, which is detected by the sensor, so that the mass flow rate turns into a target value, on the basis of a physical quantity measured or detected in relation to a heat load on the main engine and characteristics of the turbocharger,
wherein when pressure of the pressurized gas and/or the exhaust gas is equal to or more than the pressure at draft, supplying of the pressurized gas and/or the exhaust gas to the gas outlet is started, and when the pressure of the pressurized gas and/or the exhaust gas is equal to or less than the pressure at the draft, supplying of the pressurized gas and/or the exhaust gas to the gas outlet is stopped.
10. The frictional resistance reduction device for a vessel according to claim 4 , wherein the gas outlet is provided on the bottom of the vessel, and the draft detector is provided on a side of the vessel.
11. The frictional resistance reduction device for a vessel according to claim 5 , wherein the gas outlet is provided on the bottom of the vessel, and the inclination detector is provided on a side of the vessel.