JP2512033Y2 - Hydroponics equipment - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydroponic cultivation apparatus which heat-sterilizes and cools a nutrient solution and then sends the nutrient solution to a hydroponic bed for cultivating plants, and heating and cooling the nutrient solution with a heat pump.

[0002]

2. Description of the Related Art Conventionally, as such a hydroponics device, FIG.
Are known (see JP-A-60-184331).

In FIG. 6, reference numeral 1 denotes a flow path provided with a pump P for feeding the nutrient solution 3 stored in a nutrient solution tank 2 to a hydroponic bed 5 for cultivating a plant 4, and the channel 1 is heated. A section 6 and a cooling section 7 are provided. The heating unit 6 heats and sterilizes the inflowing nutrient solution 3, and the cooling unit 7 cools the heated nutrient solution. Reference numeral 8 is a heat pump for heating the heating unit 6 and cooling the cooling unit 7, 8a is a condenser of the heat pump 8, and 8b is an evaporator of the heat pump 8. 8c is a compressor and 8d is a pressure reducing valve.

[0004]

In such a hydroponics device, since the low temperature nutrient solution 3 is heated to a high temperature and sterilized only by the heat radiated by the heat pump 8,
Since a heat pump for high power is required and the heat radiated by the heat pump 8 is used only in the heating section, there is a problem that the effective use of heat is low.

If the temperature of the nutrient solution 3 is low, the temperature may not rise to a temperature at which the fluid 5a can be sterilized in the heating section 1.
There has been a problem that sterilization cannot be performed sufficiently. Further, when the temperature of the nutrient solution 3 is high, the temperature of the heated nutrient solution 3 becomes too high, and the cooling unit 7 cannot cool it to a predetermined temperature, which has a problem of affecting the growth of plants. . To solve this problem, the heat pump 8 may be controlled. However, when the heat pump 8 is controlled to increase the heat radiation amount of the condenser 8a, the heat absorption amount of the evaporator 8b also increases, so that the temperature of the nutrient solution 3a to be heated while keeping the temperature of the cooled nutrient solution 3b constant. Only raise or vice versa,
There is a problem that it is difficult to control only the temperature of the nutrient solution 3b while keeping the temperature of the nutrient solution 3a constant, and it is very difficult to control the temperature.

The present invention has been made in view of the above problems, and an object thereof is to enable heat sterilization with a heat pump for small electric power and to easily control heating and cooling of a nutrient solution. Another object of the present invention is to provide a hydroponics device capable of effectively utilizing heat.

[0007] This invention is to achieve the above object, according to
In the invention of item 1, a hydroponic bed for cultivating a plant with a nutrient solution, a nutrient solution tank for storing the nutrient solution, and a flow path for allowing the nutrient solution in the nutrient solution to flow into the nutrient solution bed. , The above
Equipped with a heat pump for heating and cooling the nutrient solution ,
Provided with a heating unit to sterilize by heating the nutrient solution on the upstream side of the flow path, in hydroponics device provided with a cooling unit for cooling the nutrient solution heated in the heating unit to the downstream side of the flow path There is a hot water tank for storing hot water heated by the heat radiating section of the heat pump, and a hot water circulation path connecting the hot water tank and the heating section,
A warm water pump for circulating warm water in the warm water circulation path to heat the nutrient solution flowing into the heating section with warm water,
A cold water tank for storing cold water cooled by the heat absorption section of the heat pump, a cold water circulation path connecting the cold water tank and the cooling section, and circulating cold water through the cold water circulation path to flow into the cooling section. A cold water pump for cooling the nutrient solution with cold water, and a channel between the heating unit and the cooling unit, heat-exchanges the nutrient solution before heating with the nutrient solution that has passed through the heating unit, and then heats it. And a heat exchanger that is passed through the section.

Further, in the invention of claim 3, a hydroponic bed for cultivating a plant with a nutrient solution, a nutrient solution tank for storing the nutrient solution, and a nutrient solution in the nutrient solution for the nutrient solution bed. A circulation path for circulating the nutrient solution into the nutrient solution tank, a heating section for injecting the nutrient solution in the nutrient solution tank for heat sterilization, and a cooling section for cooling the heated nutrient solution. A sub-circulation path for returning to the liquid tank and heat for heating and cooling the nutrient solution.
A hydroponic cultivation apparatus comprising a pump, a hot water tank for storing hot water heated by a heat radiating section of the heat pump, a hot water circulation path connecting the hot water tank and the heating section, and hot water for the hot water circulation path. Circulating a hot water pump for heating the nutrient solution flowing into the heating section with hot water, a cold water tank for storing cold water cooled by the heat absorbing section of the heat pump, the cold water tank and the cooling section. A cold water circulation path connecting the cold water circulation path, a cold water pump for circulating the cold water in the cold water circulation path to cool the nutrient solution flowing into the cooling section with the cold water, and a flow between the heating section and the cooling section. The passage is provided with a heat exchanger that heat-exchanges the nutrient solution before heating with the nutrient solution that has passed through the heating unit and then passes the heat through the heating unit.

[0009]

[Function] This invention can be stored in a warm water tank with the above configuration .
When the hot water that has circulated circulates in the hot water circuit by the hot water pump,
The nutrient solution flowing into this heating unit is heated by warm water
The nutrient solution is sterilized. Also, the nutrient solution before heating is
Heat exchange with the nutrient solution heated by the heat exchanger
Is heated by and flows to the heating section.

On the other hand, the cold water stored in the cold water tank is the cold water pump.
When it circulates through the cold water circulation path,
The supplied nutrient solution is cooled by cold water and flows to the hydroponic bed.
Going away. By the way, the nutrient solution sent to the heating unit is a heat exchanger.
Since it is heated by the
A small amount of heat is required to sterilize by heating to. Ma
In addition, the nutrient solution flowing from the heating section to the cooling section is stored in the heat exchanger.
Since it is cooled by the
Only a small amount of heat is required for cooling. As a result, for small power
The heat pump can heat and sterilize the nutrient solution.
In fact, it is possible to cool the nutrient solution that has been sterilized by heating to a predetermined temperature.
Wear.

A hot water circulation path connecting the hot water tank and the heating section.
And the cold water circulation path that connects the cold water tank and the cooling unit separately
Hot water that circulates hot water in the hot water circulation path
The pump and the cold water pump that circulates the cold water in the cold water circulation
Since they are provided separately, the heating temperature of the heating unit and the cooling unit
The cooling temperature of the
Therefore, the temperature control can be easily performed.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a hydroponic cultivation apparatus according to the present invention will be described below with reference to the drawings.

In FIG. 1, reference numeral 10 denotes a cultivation house. In the cultivation house 10, a plurality of cultivation beds 11a to 11n for cultivating a plant V with a nutrient solution and a nutrient solution tank 1 storing a nutrient solution 12 are stored.
3 and 3 are provided. This nutrient solution tank 13 and cultivation bed 1
1a to 11n are communicated with each other via the flow path 14 and the switching valves J1 to Jn. The cultivation beds 11a to 11n are also connected to the nutrient solution tank 13 by the bypass passage P and the switching valves J1 to Jn. And, the nutrient solution tank 1 by the pump 15
The nutrient solution 12 of No. 3 is sent to the cultivation beds 11a to 11n through the flow path 14 or the bypass path P and the switching valves J1 to Jn. The nutrient solution 12 sent to the cultivation beds 11a to 11n returns to the nutrient solution tank 13 again by the flow path 16.

The flow path 14 is provided with a heating section 20 for heating and sterilizing the nutrient solution 12 and a cooling section 21 for cooling the heated nutrient solution 12. Reference numeral 22 denotes a heat exchanger, which heat-exchanges the heated nutrient solution 12 with the unheated nutrient solution 12 flowing into the exchange coil 22a to raise the temperature of the unheated nutrient solution 12 and heat it. The temperature of the nutrient solution 12 is lowered.
The nutrient solution 12 whose temperature has risen in the exchange coil 22a flows into the heating section 20.

S1 is a temperature sensor for detecting the temperature of the nutrient solution heated by the heating section 20, and S2 is a temperature sensor for detecting the temperature of the nutrient solution cooled by the cooling section 21.

Reference numeral 30 denotes a hot water tank. The hot water tank 30 and the heater 20a of the heating unit 20 are connected to each other by a hot water circulation path 31, and hot water of the hot water tank 30 is circulated through the hot water circulation path 31 by a hot water pump 32. It is designed to be sent to the heater 20a of the heating unit 20. Further, the warm water tank 30 and the radiator (sub-heating unit) 33 provided in the cultivation house 10 are the sub-circulation path 3
4, the hot water in the hot water tank 30 is sent to the radiator 33 while circulating through the sub circulation path 34 by the sub pump 35. When hot water is circulated through the radiator 33, the inside of the cultivation house 10 is warmed by heat radiation. 36 is a blower fan, and S5 is a temperature sensor for detecting the temperature inside the cultivation house 10.

As shown in FIG. 2, the hot water tank 30 is connected to a heat radiating portion 41 of the heat pump 40 by a communication pipe 37. The radiator 41 is provided with a condenser 41a of the heat pump 40, and heat of the hot water flowing into the radiator 41 is heated by the heat radiation of the condenser 41a. Reference numeral 42 denotes a hot water pump that circulates the hot water in the hot water tank 30 to the heat radiating section 41. The hot water pumped by the heat radiating section 41 is sent to the hot water tank 30 by this circulation, and the hot water in the hot water tank 30 is increased to 55 to 60 degrees. It is a thing.

Reference numeral 41b is a condenser connected in parallel to the heat radiating portion 41, and the heat pump 4 is switched by switching the switching valve 51.
By flowing the refrigerant of 0 into the condenser 41b, the condenser 41b
The heat radiated by is radiated to the outside air. In this case, the warm water is not heated. Reference numeral 52 is a blower fan.

Reference numeral 43 denotes a cold water tank. As shown in FIG. 1, the cold water tank 43 and the cooling coil 21a of the cooling unit 21 are connected by a circulation path 44, and the cold water in the cold water tank 43 is circulated by a cold water pump 45. It is adapted to be sent to the cooling coil 21a of the cooling section 21 while circulating in the path 44.

The cold water tank 43 communicates with the sub-circulation path 34 through the electromagnetic switching valve G, and the switching of the electromagnetic switching valve G circulates the cold water to the radiator 33. The circulation of the cold water causes the inside of the cultivation house 10 to be circulated. The temperature can be lowered.

As shown in FIG. 2, the cold water tank 43 is connected to a heat absorbing portion 47 of the heat pump 40 by a communication pipe 46. The heat absorbing part 47 is provided with an evaporator 47a of the heat pump 40, and the cold water flowing into the heat absorbing part 47 is cooled by the heat absorption of the evaporator 47a. Reference numeral 48 denotes a cold water pump that circulates the cold water in the cold water tank 43 to the heat absorbing section 47, and the cold water cooled in the heat absorbing section 47 is sent to the cold water tank 43 by this circulation, and the temperature of the cold water in the cold water tank 43 is 10 to 15 degrees. It is something to do.

Reference numeral 47b denotes an evaporator connected in parallel with the heat absorbing portion 47, which absorbs heat from the outside air by flowing the refrigerant of the heat pump 40 to the evaporator 47b by switching the electromagnetic switching valve 49. In this case, the cold water is not cooled. 50 is a blower fan.

53 is a pressure reducing valve, 54 is a liquid receiver, 55 is a compressor, S3 is a hot water sensor for detecting the temperature of hot water in the hot water tank,
S4 is a cold water sensor that detects the temperature of the cooling water.

FIG. 3 shows each pump 15, 32, 35, 42, 45, 48, based on the temperature detected by each sensor S1 to S5.
FIG. 6 is a block diagram showing a configuration of a control system for controlling electromagnetic switching valves 49, 51, G, J1, J2 ... Jn.

In FIG. 3, reference numeral 60 is a control device comprising a microcomputer or the like, which controls the hot water pump 32 and the cold water pump 45 so that the temperatures detected by the sensors S1 and S2 are 50 and 20 degrees. Adjust the circulating hot water volume and cold water volume.

The controller 60 switches the electromagnetic switching valves 51 and 49 so that the temperatures detected by the sensors S3 and S4 are 55 to 60 degrees and 10 to 15 degrees, respectively. Further, the control device 60 performs switching of the electromagnetic switching valve G and control of the pump 35 based on the temperature detected by the sensor S5 to bring the inside of the cultivation house 10 to a predetermined temperature, and controls switching of the switching valves J1 to Jn. Then, the nutrient solution that has been sterilized by heating or the nutrient solution 12 directly in the nutrient solution tank 13 is caused to flow to the cultivation beds 11a to 11n.

Next, the operation of the heat sterilization apparatus of the embodiment constructed as described above will be described.

First, the heat pump 40 and the pumps 42, 4
8 is operated to raise the warm water in the warm water tank 21 to 55 to 60 degrees and cool the cold water in the cold water tank to 10 to 15 degrees.
After that, the hot water pump 32 and the cold water pump 45 are operated to circulate the hot water in the hot water tank 30 to the heater 20a of the heating unit 20, and circulate the cold water in the cold water tank 43 to the cooling coil 21a of the cooling unit 21. Let

On the other hand, the switching valve J1 is switched to connect the flow passage 14 to the cultivation bed 11a and the pump 15 is operated to cause the nutrient solution 12 in the nutrient solution tank 13 to flow into the flow passage 14a. On the other hand, the cultivation beds 11b to 11n have switching valves J2 to
Since it communicates with the bypass path P through Jn, the cultivation beds 11b to 11n are connected to the nutrient solution tank 13 via the bypass path P.
Nutrient solution 12 flows in.

The nutrient solution 12 flowing into the flow path 14a flows into the heating section 20 through the exchange coil 22a of the heat exchanger 22. In the heating unit 20, the nutrient solution is heated by the heater 20a. This heated nutrient solution is used in the heat exchanger 2
2 and heat exchange with the nutrient solution passing through the exchange coil 22a.

The nutrient solution passing through the exchange coil 22a is heated to about 40 degrees and flows into the heating section 20, and is heated to 50 degrees by the heater 20a to be sterilized. The sterilized nutrient solution is heat-exchanged by the heat exchanger 22 and its temperature is lowered. The nutrient solution having the lowered temperature flows into the cooling unit 21,
It is cooled to 20 degrees by the cooling coil 21a. The cooled nutrient solution 12 flows into the cultivation bed 11a via the switching valve J1.

By the way, since the nutrient solution heated by the heater 20a of the heating section 20 is heated to about 40 degrees by the heat exchanger 22, the amount of heat required for heating up to the temperature of 50 degrees for heat sterilization is small. Well, it doesn't need high power to heat. In addition, the nutrient solution cooled in the cooling unit 21 is the heat exchanger 2
Since the temperature is lowered at 2, it does not require a large amount of power to cool to 20 degrees. Therefore, the heat pump 40 may be a small one for small electric power. By the way, about 1/3 compared to the case without the heat exchanger 22
The following ones for small power may be used.

Further, for example, when the temperature of the nutrient solution cooled in the cooling section 21 becomes higher than 20 degrees, the controller 60 increases the rotational force of the cold water pump 45 to increase the amount of cold water flowing through the cooling coil 21a. Allow the nutrient solution to cool to 20 degrees. At this time, since the control device 60 only increases the rotational force of the cold water pump 45, it has no effect on the heating of the heating unit 20.

On the contrary, when the temperature of the nutrient solution heated by the heating section 20 becomes 50 degrees or less, the controller 60 increases the rotating force of the hot water pump 32 to increase the amount of warm water flowing to the heater 20a. The temperature is maintained at 50 degrees. At this time as well, the control device 60 only increases the rotational force of the hot water pump 32, and therefore has no effect on the cooling of the cooling unit 21.

In this way, heating of hot water in the hot water tank and cold water tank
The cold water is cooled by the heat pump and the hot water tank
And the heating part, and the cold water tank and the cooling part.
A separate cold water circulation path is provided to circulate the hot water in the hot water circulation path.
Cold water that circulates the hot water pump and cold water in the cold water circuit
Since it is provided separately from the pump,
The temperature and the cooling temperature of the cooling unit can be controlled independently of each other.
Therefore, the heating temperature of the heating section and the cooling temperature of the cooling section can be
It is easy to adjust the temperature to the desired temperature.
It

When the temperature of the cold water in the cold water tank 43 falls within the range of 10 to 15 degrees and the temperature of the hot water in the hot water tank 21 drops to 55 degrees or less, the heat pump 40 performs the independent heating operation. That is, the electromagnetic switching valve 51 is switched to cause the refrigerant to flow into the condenser 41a, and the condenser 41a radiates heat to the warm water to raise the temperature of the warm water in the warm water tank 30 from 55 degrees. At this time, the refrigerant that has passed through the condenser 41a and cooled is cooled by the pressure reducing valve 5
After being decompressed and expanded by passing through 3, the electromagnetic switching valve 49 causes the air to flow to the evaporator 47b and drives the blower fan 50 so that the evaporator 47b absorbs heat to the outside air to evaporate the refrigerant. Then, this evaporated refrigerant is compressed by the compressor 45.
Send to.

When the hot water temperature of the hot water tank 30 exceeds 60 degrees, the operation of the heat pump 40 is stopped.
As a result, the hot water temperature of the hot water tank 30 can be lowered to 55 to 60 degrees while keeping the cold water temperature of the cold water tank 43 at 10 to 15 degrees.

On the contrary, the temperature of the warm water in the warm water tank 30 is 55-55.
Within the range of 60 degrees, when the temperature of the cold water in the cold water tank 43 rises to 15 degrees or higher, the heat pump 40 performs the independent cooling operation. That is, the electromagnetic switching valve 51 is switched to flow the refrigerant to the condenser 41b and drive the blower fan 52 to radiate the heat of the condenser 41b to the outside air to prevent the temperature rise of the hot water in the hot water tank 30. At this time, the refrigerant that has passed through the condenser 41b and has been cooled is decompressed and expanded by passing through the pressure reducing valve 53, and then is made to flow to the evaporator 47a by the electromagnetic switching valve 49, and heat is absorbed from the cold water by the evaporator 47a to cool the refrigerant. Evaporate. Then, the evaporated refrigerant is sent to the compressor 55. As a result, the cold water in the cold water tank 43 is only cooled.

When the cold water temperature of the cold water tank 43 becomes 10 degrees or lower, the operation of the heat pump 40 is stopped. Thereby, the hot water temperature of the hot water tank 30 is set to 55 to 60.
The cold water temperature of the cold water tank 43 to 10 to 1
It can be raised to 5 degrees.

When the temperature of the hot water in the warm water tank 30 drops to 55 degrees or lower and the temperature of the cold water in the cooling tank 43 rises to 15 degrees or higher, the heat pump 40 performs the heating / cooling simultaneous operation. That is, the temperature of the hot water in the hot water tank 30 is raised to 55 to 60 degrees by switching the electromagnetic switching valve 51 to flow the refrigerant into the condenser 41a and radiate the heat to the hot water in the condenser 41a.

At this time, the refrigerant cooled by passing through the condenser 41a is passed through the pressure reducing valve 53 to be depressurized and expanded, and this refrigerant is made to flow to the evaporator 47a by the electromagnetic valve 49. Then, the evaporator 47a absorbs heat from the cold water to evaporate the refrigerant. Thereby, the cold water in the cold water tank 43 is cooled, and the temperature of the cold water is cooled to 10 to 15 degrees. The evaporated refrigerant is sent to the compressor 55.

When the cold water temperature in the cold water tank 43 drops below 10 degrees, the electromagnetic switching valve 49 is switched to allow the refrigerant to flow to the evaporator 47b, and the heat pump 40 is shifted to the independent heating operation.

On the contrary, when the temperature of the hot water in the hot water tank 30 exceeds 60 degrees, the electromagnetic switching valve 51 is switched to allow the refrigerant to flow to the condenser 41b and the heat pump 40 is shifted to the cooling independent operation.

As described above, since heating and cooling can be performed at the same time by operating one heat pump 40, efficient operation is possible and energy consumption of input power can be reduced.

The hot water in the hot water tank 30 is sent by the pump 35 to the radiator 33 provided in the cultivation house 10 to keep the inside of the cultivation house 10 at a predetermined temperature. When the temperature detected by the sensor S5 is high and cooling must be performed in the cultivation house 10, the control device 60 switches the electromagnetic switching valve G to send cold water to the radiator 33. This allows
The temperature inside the cultivation house 10 is lowered and maintained at a predetermined temperature.

As described above, since the heat radiation and heat absorption of the heat pump 40 are used for cooling and heating of the cultivation house 10, the heat can be effectively used. In addition, it is very convenient because hot water or cold water can be supplied to other places simply by pulling a pipe from the hot water tank 30 or the cold water tank 43.

When the cultivating bed 11a is filled with the sterilized nutrient solution 12, the switching valve J1 is switched to the original state and the switching valve J2 is switched to the cultivation bed 11b and the flow path 14.
And communicate with. Then, the sterilized nutrient solution 12 is caused to flow into the cultivation bed 11b in the same manner as described above.

FIG. 4 shows another embodiment. In this embodiment, a sub-circulation path 70 different from the circulation path 60 for circulating the nutrient solution is provided in the cultivation beds 11a to 11n, and the sub-circulation path 70 is provided with a heating unit 20 for heating and sterilizing the nutrient solution, and the nutrient solution. The heat exchanger 22 is provided between the cooling unit 21 for cooling and the heating unit 20 and the cooling unit 21, and the nutrient solution in the nutrient solution tank 13 is circulated to the auxiliary circulation path 70 by the pump 71 for sterilization. The prepared nutrient solution is returned to the nutrient solution tank 13.

According to this embodiment, since the switching valve J and the bypass passage P are not necessary and the distance of the flow passage 14 can be shortened, the facility cost can be reduced.

In each of the above-mentioned embodiments, the one-stage compression heat pump is used. However, if a two-stage compression heat pump or a two-stage compression heat pump is used, as shown in FIG. It is possible to set the heat sterilization temperature to 60 degrees or higher.

[0051]

[Effect] According to the present invention, the nutrient solution can be sterilized by heating with a heat pump for small electric power . Also, according to this device
If so, a hot water circulation path connecting the hot water tank and the heating unit, and a cold water tank
In addition to providing a cold water circulation path connecting to the cooling unit separately,
A hot water pump and a cold water circuit that circulate the hot water in the hot water circuit.
With a separate cold water pump that circulates the cold water of
Therefore, it is necessary to heat the hot water in the hot water tank and cool the cold water in the cold water tank.
Even if using a heat pump, the heating temperature and
It is possible to control the cooling temperature of the cooling unit independently of each other.
Therefore, the heating temperature of the heating unit and the cooling temperature of the cooling unit must be adjusted accordingly.
It becomes easy to reach the desired temperature in each case.

[Brief description of drawings]

1 is a block diagram schematically showing the configuration of a nutrient solution culture apparatus according to this invention,

FIG. 2 is a block diagram schematically showing the configuration of a heat pump,

FIG. 3 is a block diagram showing a configuration of a control system of the hydroponic cultivation device,

FIG. 4 is an explanatory diagram showing the configuration of another embodiment,

FIG. 5 is an explanatory diagram showing the configuration of a two-stage compression heat pump,

FIG. 6 is an explanatory diagram showing a configuration of a conventional hydroponics device.

[Explanation of symbols]

 11a-11n Cultivation bed 12 Nutrient solution 14 Flow path 20 Heating part 21 Cooling part 22 Heat exchanger 31 Hot water circulation path 32 Hot water pump 40 Heat pump 41 Heat dissipation part 44 Cold water circulation path 45 Cold water pump

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-60-184333 (JP, A) JP-A-3-127918 (JP, A) JP-A-63-56223 (JP, A)

Claims (3)

(57) [Scope of utility model registration request] 1. A hydroponic bed for cultivating a plant with a nutrient solution, a nutrient solution tank for storing the nutrient solution, and a flow path for allowing the nutrient solution in the nutrient solution to flow into the nutrient solution bed. The nutrient solution
With a heat pump for heating and cooling, the heating section for heating and sterilizing the nutrient solution is provided on the upstream side of the flow path, and the cooling section for cooling the nutrient solution heated by the heating section is provided. A hydroponic cultivation apparatus provided on the downstream side of a flow path, wherein a hot water tank for storing hot water heated by a heat radiating section of the heat pump, a hot water circulation path connecting the hot water tank and the heating section, and the hot water circulation A hot water pump for circulating hot water in the passage to heat the nutrient solution flowing into the heating section with the hot water, a cold water tank for storing cold water cooled by the heat absorbing section of the heat pump, the cold water tank and the cold water tank A cold water circulation path connecting the cooling unit, a cold water pump for circulating cold water in the cold water circulation path to cool the nutrient solution flowing into the cooling unit with cold water, and a heating unit and a cooling unit. Pass the unheated nutrient solution through the heating section A hydroponic cultivation apparatus comprising: a heat exchanger that heat-exchanges with the fermented nutrient solution and then passes the heat through the heating unit. 2. A sub-heating unit that heats a substance other than the fluid, a sub-hot water circulation path that circulates the sub-heating unit and the heat radiating unit of the heat pump, and hot water heated by the heat radiating unit is the sub-hot water. The submerged hot water pump which circulates in a circulation path was provided, The nutrient solution cultivation device of Claim 1 characterized by the above-mentioned. 3. A hydroponic bed for cultivating plants with a nutrient solution, a nutrient solution tank for storing the nutrient solution, and a circulation path for circulating the nutrient solution in the nutrient solution to the nutrient solution bed. A sub-circulation path having a heating part for injecting and sterilizing by heating the nutrient solution in the nutrient solution tank and a cooling part for cooling the heated nutrient solution and returning the nutrient solution passing through the cooling part to the nutrient solution tank. And heating the nutrient solution
A hydroponic apparatus comprising a heat pump for cooling and cooling, a hot water tank for storing hot water heated by a heat radiating section of the heat pump, and a hot water circulation path connecting the hot water tank and the heating section, A hot water pump for circulating hot water in the hot water circulation path to heat the nutrient solution flowing into the heating section with hot water, a cold water tank for storing cold water cooled by the heat absorbing section of the heat pump, and a A cold water circulation path connecting the water tank and the cooling unit, a cold water pump for circulating cold water in the cold water circulation path to cool the nutrient solution flowing into the cooling unit with the cold water, the heating unit and the cooling unit. Hydroponic culture characterized in that a heat exchanger for exchanging heat of the nutrient solution before heating with the nutrient solution that has passed through the heating section and then passing it through the heating section is provided in the flow path between the heating section and the section. apparatus.