JPH03236723A - Plant cultivation using thermal exhaust from thermal-power generation and system therefor - Google Patents

Abstract

PURPOSE:To provide the title system intended to prevent global warming and utilize the CO2-contg. waste heat from thermal-power generation, so designed that the CO2- contg. thermal exhaust produced by thermal-power generation is cooled to temperatures suitable for plant cultivation and introduced into plant cultivation site(s). CONSTITUTION:In the objective system 1, the thermal exhaust 3 released from a thermal power plant 2 is fed through a changeover valve 4a to an absorption refrigerating machine 5, passed through the heat sink (an evaporator) 5a of the refrigerating machine 5, and put to heat exchange with a refrigerant 6. The resulting exhaust 3 is introduced via a changeover valve 4b into a heat exchanger 7, where seawater 8 is flowing and the exhaust is put to heat exchange with the seawater 8. The resultant exhaust 3 is finally supplied to plant cultivation plant(s) 8. In the above processes, the refrigerating machine 5 is equipped with an air conditioning part 5b equivalent to a generator, and this conditioning part 5b is put into another plant cultivation plant 9. The refrigerant 6 is put to heat exchange with the thermal exhaust 3 at the heat sink 5a, vaporized and dissolved in a solution at an absorber 5c. Thence, the refrigerant takes heat from the ambient atmosphere at the air conditioning part 5b and evaporates again from the solution.

Description

[Detailed Description of the Invention] [Objective of the Invention] (Industrial Application Field) The present invention prevents global warming by not releasing into the atmosphere thermal exhaust gas that is charged with waste heat and contains a large amount of carbon dioxide from thermal power generation. The present invention also relates to a method and system for cultivating plants using heat exhaust from thermal power generation, in which the heat and carbon dioxide of the exhaust are utilized for plant cultivation.

(Prior art) Carbon dioxide is currently increasing on a global scale,
This increase in carbon dioxide causes a warming effect on the earth, raising the global temperature and causing various environmental problems such as melting of glaciers in Antarctica, rising sea levels due to engraving of seawater, and desertification of humid areas. It is thought that there are. By the way, the exhaust gas emitted from thermal power plants is tinged with waste heat, and that heat is used in economizers, etc., but this exhaust gas also contains a lot of carbon dioxide from the combustion of fossil fuels. do.

(Problem to be solved by the invention) However, the use of waste heat in the exhaust gas from this thermal power plant is limited to exhaust gas whose temperature exceeds 150°C at most, and exhaust heat with a temperature lower than that cannot be used at all. is released into the atmosphere without any air pollution. Therefore, at present, exhaust heat up to approximately 150℃ from thermal power plants not only does not effectively utilize the waste heat, or thermal energy, but also releases the carbon dioxide contained in it into the atmosphere without being processed. This means that they are also contributing to global warming.

On the other hand, plants consume carbon dioxide and release oxygen through photosynthesis, so they are thought to suppress the above-mentioned global warming through the consumption of carbon dioxide. In addition to carbon dioxide concentration, temperature also plays a major role in cultivating this plant.

The present invention has been made in view of the above circumstances, and is intended to prevent global warming by not releasing exhaust heat and carbon dioxide-rich exhaust from thermal power generation into the atmosphere. It is possible to produce many effects at once from the heat exhaust from thermal power generation, such as useful for cultivating plants that are necessary for growth, effective use of thermal energy from combustion in thermal power generation, reduction of carbon dioxide, and increase in oxygen. The present invention aims to provide methods and systems.

[Structure of the invention]

(Means for Solving the Problems) In order to solve the above problems, the present invention provides a step of cooling thermal exhaust gas containing carbon dioxide generated by thermal power generation to a temperature suitable for plant cultivation, and a step of cooling the thermal exhaust gas containing carbon dioxide generated by thermal power generation to a temperature suitable for cultivating plants. Provided is a method for cultivating plants using heat exhaust gas generated by thermal power generation, including a step of guiding the plant to a cultivation area.

The present invention also provides a heat exchanger that cools thermal exhaust gas containing carbon dioxide generated by thermal power generation to a temperature suitable for plant cultivation; Provided is a plant cultivation system using thermal exhaust generated by thermal power generation, which is equipped with a guided plant cultivation factory.

(Function) According to the method of the present invention, waste heat tinged with exhaust gas generated by thermal power generation is cooled to a temperature (30 to 40° C.) suitable for plant cultivation, mainly forced cultivation. This cooled exhaust air is then led to a plant cultivation area, where the heat and carbon dioxide contained in the exhaust air are used to grow plants.

In addition, the plant cultivation system of the present invention includes a heat exchanger that cools the heat exhaust generated by thermal power generation to a temperature suitable for plant cultivation, and a heat exchanger that isolates the plant cultivation area from the outside air and that cools the heat exhaust that is cooled by the heat exchanger. It is equipped with a guided plant cultivation factory. Therefore, the system of the present invention can realize the above method, and contributes to suppressing global warming by effectively utilizing exhaust heat and carbon dioxide from thermal power generation.

(Example) The present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a schematic diagram showing an example of the plant cultivation system of the present invention. That is, in the system 1 of this embodiment,
Thermal exhaust gas 3 released from the thermal power plant 2 is sent to the absorption chiller 5 via the switching valve 4a, and is used as the cold source of the chiller 5 (
It passes through the evaporator) 5a and exchanges heat with the refrigerant 6. Thereafter, this exhaust gas 3 is introduced into the heat exchanger 7 via the switching valve 4b. Seawater 8 passes through the heat exchanger 7, and heat exchange is performed with the seawater 8. Finally, this hot exhaust gas 3 is sent to a plant cultivation factory 8.

In this embodiment, since seawater is used as the heat exchange medium in the heat exchanger 7, the cost for heat exchange can be reduced compared to the case where an artificial cooling medium is used.

By the way, the absorption refrigerator 5 has an air conditioning unit 5 which corresponds to a generator.
b, but this air conditioning unit 5b is drawn into the plant cultivation factory 9. The refrigerant 6 exchanges heat with the heat exhaust 3 in the cold heat source 5a and is vaporized, and then is dissolved into a solution in the absorber 5c. Thereafter, the air conditioner 5b removes heat from the surrounding atmosphere and evaporates from the solution again.

Then, in the condenser 5C, it emits heat to the surroundings and liquefies it. Therefore, when the heat exhaust gas 3 in the plant cultivation factory 8 is still at a high temperature, heat exchange is further performed with the heat exhaust gas 3 in the air conditioning section 5b.

The absorption refrigerator 5 is used as a refrigerator for cooling the thermal exhaust gas 3 because it is economical because no power is used, and even exhaust gas at a low temperature of 150° C. or lower can be used as a heat source. The exhaust gas at about 150°C becomes 45 to 60°C after passing through the heat exchanger 7, and is maintained at 30 to 40°C in the plant cultivation factory 9 for forced cultivation.

In the system of this embodiment, the absorption chiller 5 having the air conditioning section 5a supplements the cooling capacity of the heat exchanger 7, but in the cold season when the temperature of the seawater 8 is low, the heat exchanger 7 alone is sufficient. Since the temperature of the thermal exhaust gas 3 can be lowered, the switching valves 4a and 4b are switched at this time to prevent the thermal exhaust gas 3 released from the thermal power plant 2 from being sent to the absorption chiller 5, and to bypass the bypass pipe 10.
immediately sent to the heat exchanger 7 via the

FIG. 2 is a schematic perspective view of the plant cultivation factory 9.

The plant cultivation factory 9 has a plant cultivation area 11 with a ceiling 9a and side walls 9b.
Although the structure is isolated from the outside air 12, an air conditioning section 5b of an absorption refrigerator is installed on the ceiling 9a. Also cultivation area 1
Slightly above the pipe 1, a watering and air supply pipe 13 through which the heat exhaust 3 and water 12 for plant cultivation flow is laid in a branched manner. In the plant cultivation area 11, plants used for various purposes such as food, ornamentation, erosion control, and rainwater accumulation can be cultivated.

FIG. 3 is a cross-sectional perspective view of the pipe 13 for supplying water and air. This watering and air supply pipe 13 includes an inner pipe 13a and an outer pipe 13.
It has a double pipe structure as shown in b, and the inner pipe 13a has a heat exhaust 3.
However, water 12 for spraying is also passed through the outer tube 13b. The heat exhaust gas 3 is discharged from each end of the multi-branched watering and air supply pipe 13 and fills the plant cultivation factory 9, but a large number of water 12 for spraying are provided on the wall of the outer pipe 13b. The water is sprayed little by little from the small-diameter watering holes 14, and evenly distributed over the plant cultivation area 11.

According to this pipe 13, the heat exhaust gas 3 flowing through the inner tube 13a is cooled by the water 12 flowing through the outer tube 13b. It plays a role of supplementing the cooling action of the refrigerator 5. Therefore, the heated exhaust gas 3 will not be introduced into the plant cultivation factory 9 at a temperature that would damage the plants.

Therefore, in this embodiment, by employing the pipe 13 for water sprinkling and air supply, the function of the heat exchanger 7 can be partially replaced and the heat exchanger 7 can be made smaller, and the installation cost of the heat exchanger 7 can be reduced. Costs can be reduced. Furthermore, the water and air supply pipe 13 can save labor in installation work compared to installing a water supply pipe and an air supply pipe separately.

If the temperature of the heat exhaust 3 in the plant cultivation factory 9 exceeds the optimum temperature of 30 to 40°C for forced cultivation, when the heat exhaust 3 with high temperature and light specific gravity rises, the ceiling 9a
Heat exchange is performed with the refrigerant 6 passing through the air conditioning section 5b of the absorption refrigerator.

In the plant cultivation factory 9 of this embodiment, by installing the air conditioning unit 5b of the absorption chiller above the watering and air supply pipe 13, it is possible to maintain an appropriate internal temperature using air convection. can.

In this embodiment, the final cooling of the heat exhaust 3 is performed within the plant cultivation factory 9. For this reason, when the plant cultivation factory 9 is cooled too much, the moisture contained in the exhaust air reaches saturated vapor pressure and condenses, and when it is then heated inside the plant cultivation factory 9, it becomes an atmosphere with less moisture necessary for plants. There is no fear that this will happen.

As described above, according to the system 1 of the present embodiment, the heat exhaust gas 3 of 150° C. or lower, which has been released into the atmosphere from the thermal power plant 2, is transferred to the cold heat source 5 a s heat exchanger of the absorption chiller 5. 7 and the water-sprinkling air supply pipe 13 to be introduced into the plant cultivation factory 9 through three stages of cooling, and further cooled in the air conditioning section 5b of the absorption chiller 5. Therefore, the heat exhaust gas 3 generated by thermal power generation is cooled without waste, providing an ambient temperature suitable for cultivating plants. Furthermore, although the thermal exhaust gas 3 contains a large amount of carbon dioxide, which is the cause of global warming, this carbon dioxide is also effectively used as an element necessary for plant growth.

〔Effect of the invention〕

As explained above, according to the method and system of the present invention, waste heat and carbon dioxide, which would have a negative impact on the environment if the thermal exhaust generated by thermal power generation were released directly into the atmosphere, can be used for plant cultivation. t1In addition to environmental conservation, it is possible to grow plants, which are beneficial to humans and the environment.

FIG. 1 is a schematic diagram of a plant cultivation system according to an embodiment of the present invention, FIG. 2 is a schematic perspective view of a plant cultivation factory according to the embodiment, and FIG. 3 is a diagram of a water supply and air supply pipe according to the embodiment. It is a cross-sectional perspective view.

3... Heat exhaust, 5... Absorption chiller, 5a... Air conditioner, 7... Heat exchanger, 8... Seawater, 9... Plant cultivation factory, 13... Watering Air supply pipe.

Claims (1)

[Claims] 1. (1) A step of cooling thermal exhaust gas containing carbon dioxide generated by thermal power generation to a temperature suitable for plant cultivation;
2) A method for cultivating plants using thermal exhaust gas generated by thermal power generation, including the step of guiding the cooled thermal exhaust gas to a plant cultivation area. 2. A heat exchanger that cools the heat exhaust gas containing carbon dioxide produced by thermal power generation to a temperature suitable for plant cultivation, and a plant that isolates the plant cultivation area from the outside air and to which the heat exhaust air cooled by the heat exchanger is guided. A plant cultivation system that utilizes heat exhaust from thermal power generation and is equipped with a cultivation factory. 3. The plant cultivation system according to claim 2, wherein the heat exchanger exchanges heat between the heat exhaust and seawater. 4. Any one of claims 2 to 3, further comprising an absorption refrigerator having an air conditioning unit that cools the heat exhaust gas before exchanging heat with the heat exchanger and cools air inside the plant factory. Plant cultivation system as described in section. 5. The plant cultivation factory includes a watering and air supply pipe having a double pipe structure in which the air supply pipe for passing the heat exhaust gas is covered with a watering pipe for watering the plants. plant cultivation system. 6. The plant cultivation system according to claim 5, wherein the watering and air supply pipe is installed below the air conditioning section of the absorption refrigerator in the plant cultivation factory.