JP2010051236A - Method and apparatus for controlling water circulation in oceanic bonito-fishing boat - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve energy saving by reducing power required for various pumps and a cooling device for fresh sea water in a live bait device of an oceanic bonito-fishing boat. <P>SOLUTION: The apparatus for controlling water circulation includes a circulation passage 14 of rearing water, interposed between a plurality of live bait containers 12, an aeration tank 26, and a regulation tank 16, a fresh sea water-supplying passage 34 for pumping up the fresh sea water from the outside of the boat, a water-discharging passage 44 for discharging a part of the circulating water to the outside of the boat, a heat-exchanger 40 for exchanging heat between the fresh sea water and discharged water for primary cooling, and a cooling device 50 forming a freezing cycle for secondarily cooling the primarily cooled fresh sea water, supplying the secondary cooled fresh sea water to the circulation passage 14, reducing the amount of circulating water in the circulation passage 14, while maintaining the set amount of ventilation water of each of the live bait containers 12 corresponding to the reduction of the number of the live bait containers for rearing the live bait, controlling so that the amount of the fresh sea water supplied to the amount of water circulated is equal to or larger than the required amount relative to the set amount of ventilation water, also detecting the water surface level L of the regulation tank 16 and controlling the amount of water discharged so as to maintain the water level uniformly. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

The present invention relates to a pelagic rod single fishing fishing boat equipped with a live bait tank for raising live bait such as a live carp, reducing the power of pumps and cooling devices for circulating circulating water or supplying fresh seawater to the live bait tank. The present invention relates to a circulating water control method and apparatus that make it possible.

In an ocean-going single-fishing fishing boat, for example, 10 to 14 live bait tanks are used for feeding bait to the fishing ground as a bait storage. The volume of each live food tank is, for example, 20 to 30 m ³ . A pelagic fishing boat is often operated in the ocean with a water temperature of about 27-30 ° C.
On the other hand, sardine alive being farmed in Katsuesaso, when the water temperature rises above 27 ° C., since rapid mortality is high, the water temperature in the Katsuesaso is the optimal temperature for farming sardine It is kept at about 14-17 ° C. Further, while water exchange by circulating the environmental water in Katsuesaso, to prevent contamination of the fish tank is a factor in the death of Katsuiwashi (such as ammonia), at a ratio of 30% or more of water exchange amount fish tank It is said that it is good to take in fresh seawater.

Patent Document 1 (Japanese Patent Laid-Open No. 57-36921) discloses a live bait device in a fishing boat proposed by the present applicant. Hereinafter, this live food device will be described with reference to FIG.
In FIG. 5, a cultivation tank 01 for raising live fish shellfish, an aeration apparatus 02 for supplying oxygen to the cultivation tank environmental water and removing carbon dioxide, and a circulation pump P ₁ are connected by a circulation path 03. On the downstream side and upstream side of the aeration apparatus 02 in the circulation path 03, a fresh seawater supply path 04 for supplying fresh seawater outside the ship and a drainage path 05 for discharging low-temperature drainage from the storage tank 01 to the outside of the ship are connected. ing.

The outboard fresh seawater pumped up in fresh sea water supply passage 04 by fresh sea water pump P _2, fresh seawater pumped up in fresh sea water supply path 04 is supplied to the circulation path 03 through the primary cooler 06 and a secondary cooler 07 Is done. A cooling device 012 for cooling the pumped fresh seawater is provided. The cooling device 012 is a secondary cooler 07, a refrigerant compressor 08, a condenser 09, an expansion valve 010, and a refrigerant path for circulating the refrigerant to these devices. A refrigeration cycle consisting of 011 is configured.
The drainage channel 05 branches from the connection with the circulation channel 03, is introduced into the condenser 09 of the cooling device 012 through the flow rate adjusting valve 013 and the primary cooler 06, and is further led out of the ship.

In this configuration, fresh fresh seawater pumped up by the sea water pump P _2, the primary cooler 06 the low-temperature waste water and to heat exchange through the flow control valve 013 from the circulation path 03 to pre-cool. Thereafter, the low temperature waste water is liquefied by the condenser 09 and then discharged out of the ship.
Fresh seawater is precooled by the primary cooler 06, then cooled by the secondary cooler 07, and then supplied to the circulation path 03.

  In the live bait device of Patent Document 1, the fresh seawater is pre-cooled by heat exchange with the low-temperature drainage in the primary cooler 06, and the high-temperature gas refrigerant is liquefied in the low-temperature drainage after precooling the fresh seawater, As a result, the required power of the cooling device 012 is reduced.

JP 57-36921 A

As described above, a large number of pumps such as the circulation pump P ₁ , the fresh seawater pump P ₂ , and other drainage pumps provided in the drainage channel 05 are used in the live bait device for a pelagic fishing boat. The total power is over 100kW.

When the operation starts, the bait is caught in the bait, so the bait is consumed as the operation progresses. Therefore, the number of live food tanks for feeding bait decreases with a decrease in bait. When the number of live food tanks decreases, it is necessary to adjust the amount of water exchange in the entire live food tank . In this case, conventionally, the amount of circulating water in the live food tank has been adjusted by lowering the pump capacity by adjusting the opening of the discharge valve of the circulation pump and lowering the head of the circulation pump. However, even if the flow rate is reduced by the discharge valve, the reduction amount of the pump power is small and the operation is inefficient.

As for the fresh seawater pump, it was difficult to adjust the flow rate of the fresh seawater pump, so the pumped volume before the decrease was maintained even if the number of live food tanks decreased. As a result, the supply amount of fresh seawater of 30% or more of the water exchange amount was maintained. Therefore, even if the number of live food tanks decreased, the power of the pump that pumps fresh seawater and the load of the cooling device that cools the fresh seawater did not decrease.

In addition, in a cooling device that cools fresh seawater, when a screw compressor is used as the compressor, the capacity control of the screw compressor is performed by bypassing the suction gas immediately before compression and returning it to the suction side by a slide valve. Yes. Incidentally, in the case of a reciprocating compressor, a mechanism is employed in which the suction gas is bypassed by performing a compression operation while the suction valve is open.
Because of such a mechanism, the screw compressor has a wide capacity control range and can be used up to an area that cannot be followed by the phase control of the reciprocating compressor. Therefore, the screw compressor is used in a wide load area such as a single fishing boat.

  However, in a single-fishing fishing boat with many low loads, the slide valve type capacity control has a problem that when the load is low, power consumption is large with respect to the refrigerating capacity and the cooling efficiency deteriorates.

In addition, as shown in FIG. 6, when a drainage pump P ₃ is provided in the drainage channel 05 and the low-temperature drainage is supplied to the primary cooler 06, the drainage channel is used to adjust the flow rate of the drainage pump P _3. A return pipe 014 is provided in 05, and an electromagnetic valve 015 is provided in the return pipe 014, and the flow rate of the low-temperature drainage is adjusted by opening and closing the electromagnetic valve 015.
However, since the opening / closing of the solenoid valve 015 is on / off control, the flow rate of the low temperature drainage cannot be adjusted with high accuracy.

  An object of the present invention is to achieve energy saving by reducing the power required for various pumps and cooling devices in a live bait device for a pelagic single fishing boat.

In order to achieve such an object, the circulating water control method for a pelagic fishing boat of the present invention comprises:
A circulation path for recreational water with multiple live food tanks and aeration tanks for live food storage, a fresh seawater supply path for pumping fresh seawater from the outside of the ship, and a drainage path for discharging a portion of the circulating water to the outside of the ship A heat exchanger that heat-exchanges fresh seawater with waste water and performs primary cooling, and a cooling device that forms a refrigeration cycle and performs secondary cooling of the freshly-cooled fresh seawater. In a circulating water control method for a pelagic fishing boat that is supplied to a circulation path,
Reducing the circulating water amount in the circulation path while maintaining the set water exchange amount of each live food tank in response to a decrease in the number of live food tanks during live food storage ;
Controlling the amount of fresh seawater so that the amount of fresh seawater supplied to the circulation path is greater than or equal to a necessary amount with respect to the set amount of water exchange ;
And a step of detecting the water surface level of the adjustment tank provided in the circulation path and controlling the amount of drainage discharged from the circulation path so as to maintain the water surface level constant .

In the method of the present invention, in response to a decrease in the number of live food tanks for feeding live food, the circulation amount of the environmental water in the live food tank is decreased, and the mixing ratio of the fresh seawater amount to the circulation water amount is always constant. Control to be. Moreover, the water level of the adjustment tank provided in the circulation path is detected, and the amount of drainage discharged from the circulation path is controlled so as to keep the water level constant . As a result, the amount of fresh seawater pumped can be reduced while maintaining the set amount without reducing the amount of water exchanged in the live bait tank and reducing the proportion of fresh seawater added to the circulating water. Therefore, while maintaining the storage environment of a live food tank, while reducing the required power of a fresh seawater pump, the power of the cooling device which cools fresh seawater can also be reduced, and, thereby, the energy saving of a live food device can be achieved.

  In the method of the present invention, the amount of circulating water in the circulation path, the amount of fresh seawater in the fresh seawater supply path, and the amount of drainage in the drainage path are controlled by controlling the number of revolutions of a transfer pump provided in each of these flow paths, It is good to carry out secondary cooling of fresh seawater to preset temperature by controlling rotation speed of a rotary compressor.

When the rotational speed of the transfer pump is controlled, the rotational force (torque) of the transfer pump is inversely proportional to the square of the fluid velocity. Therefore, if the flow rate of the pump is reduced by controlling the rotational speed, the required power is increased to the third power of the rotational speed. Proportionally decreases. As a result, the number of revolutions of the transfer pump provided in each flow path is controlled, and by operating at a low number of revolutions corresponding to the decrease in the number of live food tanks for feeding live food , significant energy saving (power saving) Is possible.

In addition, by controlling the rotational speed of the rotary compressor of the cooling device that constitutes the refrigeration cycle so that the fresh seawater is secondarily cooled to the set temperature, the pelagic fishing boat with many low-load operations can be operated at a low load. Because it can reduce power consumption at the time, further energy saving can be achieved.
Also, when starting the pump or rotary compressor, there is no risk of generating a large current as compared with the conventional starting method, and a stable linear start is achieved, so the load on the generator is also reduced.

In addition, the circulating water control device for the pelagic fishing boat of the present invention that can be directly used in the method of the present invention,
A circulation path for recreational water with multiple live food tanks and aeration tanks for live food storage, a fresh seawater supply path for pumping fresh seawater from the outside of the ship, and a drainage path for discharging a portion of the circulating water to the outside of the ship A heat exchanger that heat-exchanges fresh seawater with waste water and performs primary cooling, and a cooling device that constitutes a refrigeration cycle and performs secondary cooling of the primary cooled fresh seawater, and circulates the secondary cooled fresh seawater. In the circulating water control device for pelagic fishing boats that are supplied to the road,
A transfer pump that is provided in each of the circulation path, fresh seawater supply path, and drainage path and that can control the capacity by controlling the number of revolutions, an adjustment tank that is provided in the circulation path, and a level that detects a water surface level in the adjustment tank Control the amount of drainage discharged from the drainage channel and the amount of fresh seawater supplied to the circulation channel so that the water level in the adjustment tank is always constant by inputting the level detection value of the detector and the level detector And a controller to
Corresponding to the decrease in the number of live food tanks during live food farming, the circulating water volume in the circulation path is reduced while maintaining the set water exchange rate in each live feed tank, and supplied to the circulation path by controlling the capacity of the transfer pump. Control the amount of fresh seawater supplied so that the amount of fresh seawater to be exceeded is greater than the required amount, and maintain the water level of the adjustment tank provided in the circulation path constant by the controller. The amount of drainage discharged from the circulation path is controlled .

In the device of the present invention, in accordance with the decrease in the number of live food tanks due to consumption of live food , the live water tank reduces the circulating water volume so as to maintain the set water exchange amount, and the mixing ratio of fresh seawater to the circulating water Is controlled so as to be always constant, so that the amount of fresh seawater pumped up can be reduced with a decrease in the number of live food tanks . Therefore, the required power of the fresh seawater pump can be reduced, and the power of the cooling device for cooling the fresh seawater can be reduced.
In addition, by controlling the number of rotations of the transfer pumps provided in the circulation path, fresh seawater supply path and drainage path, and controlling the flow rate, each transfer corresponds to the decrease in the live food tanks that feed live food. The pump can be operated at a low rotational speed, and significant energy saving (power saving) becomes possible.

In addition, since the amount of drainage discharged from the circulation path is controlled so as to keep the water level of the adjustment tank provided in the circulation path constant, the amount of drainage can be reduced according to the decrease in the number of live food tanks due to consumption of live food. The power of the drain pump can be reduced. Furthermore, it becomes easy to stabilize the circulating water amount of the environmental water circulating through the live food tank and to maintain the water exchange amount of each live food tank at the set value.

Further, in the present invention apparatus, the aeration tank upstream of the circulation path air mixer provided in the air mixer is to connect the air supply pipe, and air pressure sensor for detecting the air pressure in the air supply pipe, A controller for controlling the amount of circulating water in the circulation path based on the detection value of the air pressure sensor may be provided, and the oxygen dissolved amount of the circulating water may be held at a set value by the controller.
As a result, the amount of dissolved oxygen in the circulating water can be maintained at an amount suitable for livestock cultivation.

According to the method of the present invention, a storage water circulation path provided with a plurality of live food tanks and aeration tanks for storing live food, a fresh seawater supply path for pumping fresh seawater from the outside of the ship, and a part of the circulating water Prepare a drainage channel that discharges to the outside of the ship, a heat exchanger that heat-exchanges fresh seawater with wastewater and performs primary cooling, and a cooling device that configures the refrigeration cycle and performs secondary cooling of primary seawater that has been primarily cooled. In the circulating water control method of a pelagic fishing boat that supplies freshly cooled fresh seawater to the circulation path, the set refill amount of each live food tank is set corresponding to the decrease in the number of live food tanks during livestock farming. Maintaining the circulating water volume in the circulation path while maintaining , controlling the fresh seawater volume so that the fresh seawater volume supplied to the circulation path is greater than or equal to a necessary amount with respect to the set water exchange volume , and the circulation Detects the water level of the adjustment tank provided on the road and keeps the water level constant Reducing and controlling the amount of waste water discharged from the circulation path so as to maintain, by consisting of, in accordance with the Katsuesaso number of loss associated with continuation of fishing operations, the amount of water discharged pumping amount and the circulating water fresh seawater Therefore, the amount of fresh seawater supplied, the pump power required for supplying fresh seawater, and the power required for the cooling device required for cooling the fresh seawater can be reduced, so that significant energy saving can be achieved compared to the conventional case.

In addition, according to the present invention device, a circulation path of the farm water provided with a plurality of live food tanks and aeration tanks for breeding live food, a fresh seawater supply path for pumping fresh seawater from the outside of the ship, and one of the circulating water A drainage channel that discharges the part out of the ship, a heat exchanger that heat-exchanges fresh seawater with wastewater and performs primary cooling, and a cooling device that forms a refrigeration cycle and performs secondary cooling of primary seawater that has been primarily cooled, In a circulating water control device for a pelagic fishing boat that supplies freshly cooled fresh seawater to the circulation path, capacity control is possible by controlling the number of revolutions provided in the circulation path, fresh seawater supply path, and drainage path, respectively. A transfer pump, an adjustment tank provided in the circulation path, a level detector for detecting a water surface level in the adjustment tank, and a level detection value of the level detector to input a water level in the adjustment tank. Discharge from the drainage channel so that it is always constant Comprising a controller for controlling the fresh seawater quantity to supply to the water volume and said circulation path, and the while maintaining the set renewal of corresponding respective active bait tank volume reduction of Katsuesa vessel in Katsuesa farming circulation The amount of fresh seawater supplied to the circulation path by controlling the capacity of the transfer pump is controlled so that the amount of fresh seawater is greater than the required amount with respect to the set amount of water exchange, By controlling the amount of drainage discharged from the circulation path so that the water level of the adjustment tank provided in the circulation path is kept constant by the controller, the number of live food tanks can be reduced as the fishing operation continues. Accordingly, the amount of fresh seawater pumped up and the amount of drained circulating water can be reduced. Accordingly, the pump power required for supplying fresh seawater and circulating water and the required power of the cooling device required for cooling the fresh seawater can be reduced, so that significant energy savings can be achieved as compared with the prior art.

  Hereinafter, the present invention will be described in detail with reference to embodiments shown in the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the component parts described in this embodiment are not intended to limit the scope of the present invention to that unless otherwise specified.

An embodiment of the present invention will be described with reference to FIGS. FIG. 1 is an overall configuration diagram of a live bait device for a pelagic fishing boat according to the present embodiment.
In FIG. 1, for example, a total of 14 live bait tanks 12A, 12B,... Each Katsuesaso 12 has a per vessel e.g. volume of 20 to 30 m ^3. Each Katsuesaso 12 circulation path 14 for each renewal is connected, the seawater in each Katsuesaso in renewal amount set is circulated. Renewal amount (m 3 ^{/ h)} is obtained by subtracting the amount flowing to the feed trough from the sum of the circulation amount of environmental water within Katsuesaso (m 3 ^{/ h)} with fresh sea water supply amount (m 3 ^{/ h)} Flow rate.

The seawater circulation path 14 is provided with an adjustment tank 16 and a plurality of seawater circulation pumps 18 are provided in parallel. Each seawater circulation pump 18 is provided with an inverter circuit 20, and the inverter circuit 20 is configured so that the rotation speed of each seawater circulation pump 18 can be controlled steplessly. The liquid level L in the adjustment tank 16 is detected by the level meter 22, and the amount of circulating water in the seawater circulation path 14 is controlled by the controllers 32 and 49 so that the liquid level L is always constant.

  In the seawater circulation path 14, an air mixer 24 is provided on the downstream side of the seawater circulation pump 18, and an aeration tank 26 is provided on the downstream side of the air mixer 24. Air is supplied to the air mixer 24 from the blower 26 through the pipe 28, and the air pressure passing through the pipe 28 is detected by the pressure sensor 30. Then, the inverter 32 is controlled by the controller 32 so that the air pressure in the pipe 28 becomes the set pressure, and the rotational speed of the seawater circulation pump 18 is controlled. Thereby, the dissolved oxygen amount of the circulating water in the aeration tank 26 can be always set to a set value.

  The live bait apparatus 10 is provided with a fresh seawater supply path 34 for pumping fresh seawater outside the ship. A fresh seawater pump 36 is provided in the fresh seawater supply path 34, and fresh seawater outside the ship is pumped up by the fresh seawater pump 36. The pumped fresh seawater at 30 ° C. is first cooled to 18 ° C. by the heat exchanger 40, then cooled to 14 ° C. by the seawater cooler 42, and then supplied to the seawater circulation path 14. The fresh seawater pump 36 is provided with an inverter circuit 38, and the fresh seawater pump 36 is steplessly controlled by the inverter circuit 38 so that the flow rate can be controlled.

The adjustment tank 16 is provided with a drainage path 44 for circulating water, and the drainage path 44 is provided with a plurality of drainage pumps 46 in parallel. The drain pump 46 is provided with an inverter circuit 48 so that the inverter circuit 48 can control the rotation speed of the drain pump 46 steplessly. As a result, the flow rate of the drainage pump 46 can be controlled. The 16 ° C. drainage discharged from the adjustment tank 16 by the drainage pump 46 is heat-exchanged with the fresh seawater by the heat exchanger 40, and after precooling the fresh seawater, it is discharged outside the ship.

The fresh seawater pumped up by the fresh seawater pump 36 and supplied to the seawater circulation path 14 and the drainage discharged from the drainage path 44 are controlled to have the same amount, whereby the liquid level in the adjustment tank 16 L is always kept constant. That is, the rotational speed of the drainage pump 46 is controlled by the controller 49 so that the liquid level L is constant.

The live bait apparatus 10 is provided with a cooling device 50 constituting a refrigeration cycle using a refrigerant, for example, NH ₃ as a refrigerant. A screw compressor 52 is used as the compressor of the cooling device 50. The drive motor 54 of the screw compressor 52 is provided with an inverter circuit 56, and the inverter circuit 56 can control the rotational speed of the rotor shaft of the screw compressor 52. The refrigerant is supplied from the screw compressor 52 to the seawater cooler 42 through a condenser and an expansion valve 60 (not shown) provided in the refrigerant circulation path 58 to cool fresh seawater with the refrigerant.

The controller 62 controls the opening degree of the inverter circuit 56 and the expansion valve 60, and a temperature sensor 64 for detecting the temperature of fresh seawater is provided in the fresh seawater supply path 34 downstream of the seawater cooler 42. The controller 62 controls the rotational speed of the drive motor 54 and the amount of refrigerant flowing in the seawater cooler 42 so that the temperature of the seawater becomes 14 ° C.
A manual operation valve 66 for adjusting the flow rate is provided in each flow path of the live bait apparatus 10.

In the live bait apparatus 10 having such a configuration, the 30 ° C. fresh seawater pumped from the outside of the ship to the fresh seawater supply channel 34 is cooled to 18 ° C. by the drainage by the heat exchanger 40 and further cooled to 14 ° C. by the seawater cooler 42. Is supplied to the circulation path 14. In order to prevent contamination of the live bait tank 12 (ammonia etc.), which is a cause of the death of the bait , supply fresh seawater of 30% or more of the water exchange amount.
For example, when the capacity of the live food tank 12 is 30 m ³ , the supply water amount of the live food tank is 45 m ³ / h, of which the circulating water amount is 30 m ³ / h and the fresh seawater supply amount is 15 m ³ / h. And

Thus, as shown in FIG. 1, the temperature of the circulating water supplied to the live bait tank 12 with fresh seawater is set to 15 ° C., the temperature of the circulating water exiting the live bait tank 12 and the drainage discharged from the drainage channel 44. The temperature is controlled to be 16 ° C.

Bonito pole and line the vessels, in addition Katsuesaso 12 comprises a plurality of frozen bonito that captured filled with a -20 ° C. brine (NaCl) instantaneously, for example, a freezing chamber of the fourth reactor. The configuration of the refrigeration apparatus 70 that supplies brine to the freezing tank will be described with reference to FIG. In FIG. 2, the refrigeration apparatus 70 constitutes a refrigeration cycle using, for example, NH ₃ as a refrigerant. The compressor 72 is a screw compressor, and its rotor shaft is rotationally driven by a drive motor 74.

The drive motor 74 is provided with an inverter circuit 76, and the inverter circuit 76 can control the rotation speed of the drive motor 74 steplessly. In the refrigeration apparatus 70, the refrigerant is sent from the screw compressor 72 to the brine cooler 88 through a condenser and an expansion valve 80 (not shown) provided in the refrigerant circulation path 78. The brine (NaCl) cooled to −20 ° C. by the low-temperature refrigerant in the brine cooler 88 is sent to a freezing tank (not shown) and stored in the freezing tank . Then, the caught salmon is put in the freezing tank and frozen. The salmon frozen in the freezing tank is then put into an active bait tank that is emptied by consuming the live salmon as bait. The live food tank is provided with a directly-expanded hairpin coil, low temperature brine is supplied to the hairpin coil, and the inside of the live food tank is kept at -50 ° C.

  A pressure sensor 84 is provided in the refrigerant circulation path 78 on the outlet side of the brine cooler 88. The controller 86 detects the refrigerant pressure passing through the refrigerant circulation path 78 by the pressure sensor 84, and the controller 86 keeps the refrigerant pressure at the set value so that the controller 86 rotates the rotational speed of the drive motor 74 of the screw compressor 72 and the opening degree of the expansion valve 80. To control.

When fishing operation progresses, bait in Katsuesaso sardine is consumed, decreases Katsuesaso to farming the Esaiwashi. Live bait tanks that are free of bait are not required to maintain an environment for cultivating bait, and are used as cold storage tanks for fish that have been caught as described above.
In this embodiment, the amount of circulating water and the amount of fresh seawater pumped up are reduced in proportion to the decrease in the live food tank that feeds the bait , thereby keeping the water conversion rate constant with respect to the decrease in the live food tank. I am doing so.

For this reason, since the pumping amount of fresh seawater can be reduced corresponding to the decrease in the live bait tank for feeding bait, the required power of the fresh seawater pump 36 can be reduced and the cooling device 50 required for cooling the fresh seawater is required. Power can be saved corresponding to the amount of fresh seawater.
For example, a Katsuesaso 14 tank for stocking the Esaiwashi, volume of each Katsuesaso is a 30 m ^3, the initial circulating water is at 432m ^3, and the supply amount of fresh seawater was 200 meters ³ .
Thereafter, when the number of live food tanks for feeding bait is reduced to 7 tanks , if the conventional method is used, the supply amount of fresh seawater is not changed to 200 m ³ , but in this embodiment, the supply quantity of fresh seawater is reduced to half to 100 m ³ . Therefore, the power of the fresh seawater pump 36 and the drainage pump 46 can be reduced, and the required power of the cooling device 50 is also halved. Therefore, significant energy saving can be achieved as compared with the conventional method.

Further, when the rotational speed of the seawater circulation pump 18, the fresh seawater pump 36, and the drainage pump 46 is controlled, the pump flow rate is proportional to the rotational speed and the necessary power is proportional to the third power of the rotational speed. Get smaller.
Therefore, by controlling the rotational speed of the pumps and operating at a low rotational speed when the load is low, significant energy saving (power saving) is possible.
Further, when the pumps 18, 36, 46 and the screw compressor 52 are started, there is no possibility of generating a large current as compared with the conventional starting method, and a stable linear start is performed, so that the load on the generator is also reduced.

  In addition, the use of the screw compressor 52 as the compressor of the cooling device 50 has the advantage that the capacity control range is wide, and power consumption at low load can be reduced in a pelagic fishing boat with many low load operations. Furthermore, energy saving can be achieved.

Further, in the present embodiment, the liquid level L of the circulating water in the adjustment tank 16 is detected by the liquid level meter 22, and the drainage amount of the drainage channel 44 is adjusted by the controller 49 so that the liquid level L is always constant. Since control is performed, the amount of drainage can be reduced and the power of the drainage pump 46 can be reduced as the number of live feed tanks during livestock breeding decreases, and the amount of circulating water in the live feed tank can be stabilized.
Further, since the air pressure in the pipe 28 is detected and the amount of circulating water is controlled so that the air pressure becomes a set value, the dissolved oxygen amount in the aeration tank 26 can be held at the set value. Therefore, the amount of dissolved oxygen in the live food tank 12 can be maintained at an optimum value for the survival of the bait.

FIG. 3 is a diagram showing the relationship between the rotational speed control and the flow rate (m ³ / h) when the discharge valve is closed by the conventional method of the fresh seawater pump 36 or according to this embodiment. In FIG. 3, when the required capacity is 75 m ³ / h, the conventional discharge valve closing operation consumes about 14.5 kw, whereas the rotation speed control of this embodiment gives about 8.5 kw. , 6.0 kw (45%) power reduction.

FIG. 4 shows a difference in required power between the present embodiment and the conventional cooling device 50, and shows a case where a screw compressor is used as a compressor constituting the cooling device 50. In the conventional system, even if the number of live food tanks for feeding bait is reduced, the pumping amount of fresh seawater does not change, so the required power of the fresh seawater pump 36 and the cooling device 50 does not change. Alternatively, even if the capacity of the screw compressor is controlled by the slide valve method, the power consumption is large for the refrigerating capacity at the time of low load, and the efficiency is poor.

On the other hand, in the present embodiment, the pumping amount of fresh seawater is reduced in response to a decrease in the live food tank for feeding bait, and the rotational speed of the drive motor 52 is controlled by the inverter circuit 56 in response to the decrease in the amount of fresh seawater. It responded by.
In FIG. 4, the vertical bar indicates the power difference in each refrigeration capacity (%) between the present embodiment and the conventional system. For example, when the required power is 50% of the refrigeration capacity, the power consumption of about 155 kw in the conventional bypass control is about 110 kw in this embodiment, and the power consumption of 45 kw can be reduced.

  As described above, in a live bait device having a low load operation of the cooling device, the power reduction of the cooling device is remarkable.

  ADVANTAGE OF THE INVENTION According to this invention, in the live bait | feed apparatus of a pelagic shore single fishing boat, the required motive power of the cooling devices which cool the pumps provided in each flow path and fresh seawater can be reduced, and energy saving is enabled.

1 is an overall configuration diagram of a live food device according to an embodiment of the present invention. It is a systematic diagram of the freezing device for the freezing tank according to the embodiment. It is a diagram which shows the power difference of the fresh seawater pump of the said embodiment and a conventional system. It is a diagram which shows the power difference of the cooling device of the said embodiment and a conventional system. It is a whole block diagram of the conventional live food feeder. It is a partial block diagram which shows another example of the conventional live food feeder.

DESCRIPTION OF SYMBOLS 10 Live bait apparatus 12A, 12B Live bait tank 14 Circulation path 16 Control tank 18 Circulation pump 22 Liquid level meter 24 Air mixer 26 Aeration tank 20, 38, 48, 56, 76 Inverter circuit 34 Fresh seawater supply path 36 Fresh seawater Pump 40 Heat exchanger 42 Seawater cooler 44 Drainage channel 46 Drainage pump 50 Cooling device 52 Screw compressor

Claims (5)

Multiple live bait warehouses, a circulation path that circulates the circulating water between the live bait warehouse and the adjustment warehouse, a fresh seawater supply path that pumps fresh seawater from the outside of the ship, and a drain that discharges a portion of the circulating water And a heat exchanger that primarily cools the fresh seawater by exchanging heat with the wastewater, and a cooling device that forms a refrigeration cycle and performs secondary cooling of the freshly cooled fresh seawater. In the circulating water control method for a pelagic fishing boat that is supplied to the circulation path,
Corresponding to the decrease in the number of live bait for raising live bait, the circulating water amount in the circulation path is controlled so as to maintain the live bait in the set water exchange amount, and the supply ratio of fresh seawater to the circulating water amount is always By controlling the amount of fresh seawater to be constant, the amount of fresh seawater supplied, the pump power required for fresh seawater supply, and the required power of the cooling device required for cooling the fresh seawater are reduced. To control the circulating water of fishing boats. Controlling the circulating water volume of the circulation path, the fresh seawater supply volume of the fresh seawater supply path and the drainage volume of the drainage path by controlling the number of rotations of the transfer pump provided in each of these flow paths,
The circulating water control method for a pelagic fishing boat according to claim 1, wherein the seawater is secondarily cooled to a set temperature by controlling the rotational speed of the rotary compressor of the cooling device. Multiple live bait warehouses, a circulation path that circulates the circulating water between the live bait warehouse and the adjustment warehouse, a fresh seawater supply path that pumps fresh seawater from the outside of the ship, and a drain that discharges a part of the circulating water to the outside of the ship Path, a heat exchanger that heat-exchanges fresh seawater with waste water and performs primary cooling, and a cooling device that constitutes a refrigeration cycle and performs secondary cooling of the freshly-cooled fresh seawater. In the circulating water control device for pelagic fishing boats supplied to the circulation path,
A transfer pump capable of controlling the number of rotations is provided in each of the circulation path, fresh seawater supply path and drainage path, and the live bait is maintained at a set water exchange amount corresponding to a decrease in the number of live bait for raising live bait. In this way, the flow rate of each flow path is controlled by the transfer pump so that the circulating water amount of the circulation path is controlled and the supply ratio of the fresh seawater amount to the circulating water amount is always constant. Circulating water control device for pelagic fishing boats.   A level meter that detects a circulating water level in the adjustment chamber, and a controller that controls a drainage amount of the drainage channel by inputting a detection value of the level meter so that the circulating water level is always constant. The circulating water control device for a pelagic fishing boat according to claim 3,   An aeration tank provided in the circulation path, an air mixer provided in the circulation path upstream of the aeration tank, an air pressure sensor for detecting an air pressure of an air supply pipe connected to the air mixer, and the air pressure 5. A controller for controlling the amount of circulating water in the circulation path based on a detection value of a sensor is provided, and the oxygen dissolved amount of the circulating water is held at a set value by the controller. A circulating water control device for a pelagic carp fishing boat described in 1.

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