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

Abstract

[PROBLEMS] To achieve energy saving by reducing the power required for various pumps and a cooling device for fresh seawater in a live bait device of a pelagic fishing boat.
[Solution] The circulation path 14 of the farm water which provided the several live food tank 12, the aeration tank 26, and the adjustment tank 16;, A fresh seawater supply path 34 for pumping fresh seawater from the outside of the ship, a drainage path 44 for discharging a part of the circulating water to the outside of the ship, a heat exchanger 40 for primary cooling by exchanging heat of the fresh seawater with the drainage, and freezing A cooling device 50 that constitutes the cycle and performs secondary cooling of the freshly cooled fresh seawater.Preparation, Supply freshly cooled fresh seawater to the circulation path 14LiveFeed the foodLive food tankEach corresponding to the decrease in numberLive food tank12ofSet water exchange rateTheMaintenanceWhile reducing the amount of circulating water in the circulation path 14 and controlling the amount of fresh seawater supplied to the amount of circulating water to be greater than the required amount with respect to the set amount of exchanged water, the water level L of the adjustment tank 16 is detected, The amount of drainage is controlled so as to keep the water level constant.
[Selection] Figure 1

Description

  The present invention relates to a pelagic rod single fishing fishing boat equipped with a live bait for raising live bait such as live bales and the like, and power reduction of pumps and cooling devices for circulating circulating water and supplying fresh seawater to the live bait 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 baits are used as bait farms to carry live kites to a fishing ground. The volume of each live bait 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, when the water temperature rises to 27 ° C. or higher, the dredging rate rapidly increases when the water temperature in the live bait is raised to 27 ° C. or higher. It is kept at about 17 ° C. In addition to circulating the environmental water in the live bait store, the fresh water is used in the fish store at a rate of 30% or more of the water change rate in order to prevent contamination of the fish store (such as ammonia), which is the cause of the killing of live fish. It is said that it is good to adopt.

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 storage 01 for raising live fish shellfish, an aeration device 02 for supplying oxygen to the storage environment water and removing carbon dioxide, and a circulation pump P ₁ are connected by a circulation path 03. Connected to the downstream side and the upstream side of the aeration apparatus 02 in the circulation path 03 are 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 live bait 01 to the outside of the ship, respectively. Has been.

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 04 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. For this reason, the number of live bait for feeding bait decreases with the decrease of bait. If the number of live bait holds decreases, it will be necessary to adjust the amount of water exchanged in the entire live feed hold. In this case, conventionally, the amount of circulating water in the live bait was adjusted by lowering the pump capacity by adjusting the opening of the discharge valve of the circulation pump and raising 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 pumping volume before the decrease was maintained even if the number of live baits was reduced. 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 baits was reduced, 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:
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 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 fresh seawater supply amount to be constant, the fresh seawater supply amount, the pump power required for fresh seawater supply, and the required power of the cooling device required for cooling the fresh seawater are reduced.

  In the method of the present invention, the circulation rate of the environmental water in the live bait store is reduced in response to the decrease in the live feed storey for feeding live bait, and the mixing ratio of the fresh seawater amount to the circulating water amount is always constant. To control. 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 per unit and without reducing the ratio of the amount of fresh seawater added to the circulating water. Therefore, the required power of the fresh seawater pump can be reduced, and the power of the cooling device that cools the fresh seawater can also be reduced, thereby achieving energy saving of the live bait device.

  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 rotations of the transfer pumps provided in each of the flow paths is controlled, and by operating at a low number of rotations corresponding to the decrease in live bait storage for 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 plurality of live bait warehouses, a circulation path that circulates and changes the environmental water in the live bait warehouse, a fresh seawater supply path that pumps fresh seawater from the outside of the ship, and a drainage path that discharges 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 a live bait device for a pelagic fishing boat that is supplied to the road,
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 circulating water amount in the circulation path is controlled, and the flow rate of each flow path is controlled by the transfer pump so that the supply ratio of the fresh seawater amount to the circulating water amount is always constant. .

In the device according to the present invention, in accordance with the decrease in the number of live baits that accompany consumption of live bait, the amount of circulating water is reduced so as to maintain the amount of water that the live bait has been set, and the mixing ratio of fresh seawater to the circulating water Is controlled so as to be always constant, the amount of fresh seawater pumped up can be reduced as the number of live baits is reduced. Therefore, the required power of the fresh seawater pump can be reduced, and the power of the cooling device that cools 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 respectively, and controlling the flow rate, each transfer can be performed in response to the decrease in live food storage for feeding live food. The pump can be operated at a low rotational speed, and significant energy saving (power saving) becomes possible.

  In the apparatus of the present invention, a level meter that detects a circulating water level in the adjustment unit, and a controller that controls a drainage amount of the drainage channel so that the circulating water level is always constant by inputting a detection value of the level meter. It is good to provide. Thereby, it becomes easy to stabilize the circulating water amount of the environmental water circulating through the live bait and to maintain the water exchange amount of each live bait at the set value.

In the apparatus of the present invention, the air pressure of the aeration tank provided in the circulation path, the air mixer provided in the circulation path upstream of the aeration tank, and the air supply pipe connected to the air mixer is detected. An air pressure sensor and a controller that controls the amount of circulating water in the circulation path based on a 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 plurality of live baits, a circulation path for circulating the circulating water between the live baits and the adjustment warehouse, a fresh seawater supply path for pumping fresh seawater from the outside of the ship, and a part of the circulating water A drainage channel for discharging the seawater to the outside of the ship, a heat exchanger for primary cooling by exchanging heat with fresh seawater and drainage, and a cooling device for secondary cooling of the freshly cooled seawater that constitutes the refrigeration cycle, In the circulating water control method of a pelagic fishing boat that supplies freshly cooled fresh seawater to the circulation path, the live bait is set in response to a decrease in the number of live bait for breeding live bait. By controlling the amount of fresh water in the circulation path so that the supply rate of fresh seawater is always constant with respect to the amount of fresh water, As the number of warehouses decreases, the amount of fresh seawater pumped can be reduced. Accordingly, it is possible to reduce the required power of the cooling device required for cooling the pump power and the fresh seawater required for fresh seawater supply and fresh seawater supply, significant energy savings can be achieved as compared with the prior art.

In addition, according to the present invention device, a plurality of live baits, a circulation path for circulating the circulating water between the live baits and the adjustment warehouse, a fresh seawater supply path for pumping fresh seawater from the outside of the ship, and the circulating water Equipped with a drainage channel that discharges a part 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 cools the freshly-cooled fresh seawater secondary. In a circulating water control device for a pelagic fishing boat that supplies freshly cooled fresh seawater to the circulation path, a transfer pump capable of controlling the rotation speed is provided in the circulation path, fresh seawater supply path, and drainage path, respectively. Corresponding to the decrease in the number of live bait for raising live bait, the circulating water amount of the circulation path is controlled so as to maintain the live bait for the set amount of water exchange, and the supply ratio of the fresh seawater amount to the circulating water amount Each flow path with the transfer pump so that is always constant With the arrangements to control the flow rate, in response to a decrease of the active bait number warehouse due to continuation of the fishing operation can be reduced to the amount pumped fresh seawater.
Accordingly, the amount of fresh seawater supplied, the pump power required for supplying fresh seawater, and the required power of the cooling device required for cooling the fresh seawater can be reduced, so that significant energy saving can be achieved as compared with the conventional case.

  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 holds 12A, 12B,... Each live bait 12 has a volume of, for example, 20 to 30 m ³ per store. Each live bait 12 is connected to a circulation path 14 for changing water, and the sea water in each live bait is circulated with a set amount of change. The amount of water exchanged (m ³ / h) is the flow rate obtained by subtracting the amount flowing out of the bait basket from the total amount of circulating environmental water (m ³ / h) and fresh seawater supply (m ³ / h) in the live bait. It is.

  The seawater circulation path 14 is provided with an adjustment warehouse 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 chamber 16 is detected by the level meter 22, and the amount of circulating water in the seawater circulation path 14 is controlled 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 warehouse 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 chamber 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 so as to have the same amount. 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 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 bait 12 is 30 m ³ , the amount of water supplied to the live bait is 45 m ³ / h, of which the amount of circulating water is 30 m ³ / h and the amount of fresh seawater is 15 m ³ / h. And

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

In addition to the live bait 12, the single fishing fishing boat is provided with a plurality of, for example, 4 freezers for instantaneously freezing traps filled with -20 ° C brine (NaCl). With reference to FIG. 2, the configuration of the refrigeration apparatus 70 that supplies brine to the freezer will be described. 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 screw compressor 72 is sent 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 freezer not shown and stored in the freezer. Then, the caught salmon is put in the freezer and frozen. The salmon frozen in the freezer is then put into the live bait that has been emptied by consuming live salmon as bait. The live bait is provided with a directly-expanded hairpin coil, low temperature brine is supplied to the hairpin coil, and the live bait 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.

As the fishing operation progresses, the bait in the live bait will be consumed, and the live bait that feeds the bait will decrease. The live bait where the bait is no longer needed does not need to maintain an environment for feeding bait, and is used as a cold storage 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 bait for feeding bait, thereby keeping the water conversion rate constant against the decrease in the live bait. I am doing so.

For this reason, since the pumping amount of fresh seawater can be reduced corresponding to the reduction of the live bait for raising 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, it is assumed that there are 14 live bait storages for feeding bait, the volume of each live bait store is 30 m ³ , the initial circulating water volume is 432 m ³ , and the supply amount of fresh seawater is 200 m ^3. .
Thereafter, when the live bait storage for feeding bait is reduced to half, if it is a conventional method, the fresh seawater supply amount is not changed to 200 m ³ , but in this embodiment, the fresh seawater supply amount is reduced to 100 m ³ . Therefore, the power of the fresh seawater pump 36 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.

In the present embodiment, the liquid level L of the circulating water in the adjustment chamber 16 is detected by the liquid level meter 22, and the controller 49 controls the amount of drainage of the drainage channel 44 so that the liquid level L is always constant. Since it is controlled, the amount of circulating water in the live bait 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 bait 12 can be maintained at an optimum value for 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 bait storage for feeding bait decreases, the amount of fresh seawater pumped 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 this embodiment, the pumping amount of fresh seawater is reduced corresponding to the decrease in the live bait 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 bars indicate the power difference in each refrigeration capacity (%) between the present embodiment and the conventional method. 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 apparatus for freezers which concerns on the said 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.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Live bait apparatus 12A, 12B Live bait 14 Circulation path 16 Adjustment warehouse 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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