JP2002195009A - Waste heat recovery power generating system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a waste heat recovery power generating system not necessarily require turning a low-boiling point medium to a high pressure and capable of preventing the low-boiling point medium from leaking, without having to especially install airtight wall. SOLUTION: The waste heat recovery power generating system is equipped with a heat-exchanger to pass a low-boiling point liquid from a condenser to a heating medium for waste heat and gasify the liquid and a vertically long circulating path having a vertical rising path and sinking path for fluid and filled with the liquid, in such a way that a void exists in the sinking path, and a pipe for sending the gas is opened inside the bottom of the rising path, in such a way as to face upward so that the low-boiling point gas gasified by the heat-exchanger causes the fluid in the rising path to flow upward, while a collecting pipe for the low-boiling point gas is opened at the top of the circulating path, and the condenser for the low-boiling point gas is connected to the collecting pipe, and the turbine of the generator is installed in the inside at the bottom of the sinking path of the circulating path, in such a way as to be rotated by the fluid falling down from the top.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power generation device utilizing waste heat discharged from, for example, a nuclear power plant, a thermal power plant, various chemical plants, and the like.

[0002]

2. Description of the Related Art As for a power generator utilizing waste heat, a method of rotating a turbine of a generator by steam when a strong thermal power is used, such as waste heat of an incinerator, is used. In the use of waste heat having a low target temperature, a method of rotating a turbine with a gas obtained by evaporating a low-boiling liquid by waste heat is often used. In this case, a heat exchanger for vaporizing the low-boiling liquid and a condensing device for collecting and reusing the low-boiling gas are indispensably provided.

[0003]

In the above-mentioned conventional power generating apparatus utilizing waste heat using a low boiling point medium, a very high pressure is required for the low boiling point gas in order to rotate the turbine. Not only is the above strength required,
Since the hermetic wall for preventing the leakage of the low-boiling-point gas is firmly constructed so as to surround the turbine at the center, the construction of the apparatus becomes costly, and the expected energy conversion efficiency cannot be obtained.

In order to vaporize a low-boiling medium under high pressure,
Since waste heat is unsuitable at low temperatures and requires a certain temperature or higher, there is also a problem that waste heat cannot be widely used throughout the industry.

The present invention has been made in view of the above-described circumstances,
It is an object of the present invention to provide a power generation device using waste heat, in which the pressure of a low-boiling medium is not always required to be high and the leakage of the low-boiling medium is prevented without providing an airtight wall.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a heat exchanger for vaporizing a low-boiling liquid from a condenser in a heat medium of waste heat, and a vertical rising path of the fluid. And a vertically-long circulation path that has a downward path and is filled with fluid unsatisfactorily so that an empty space is created in the downward path,
In order to allow the low-boiling gas vaporized by the heat exchanger to flow the fluid in the ascending path upward, a gas supply pipe for the gas is opened upward in the lower end of the ascending path, and the low-boiling gas is added to the upper end of the circulation path. Open the collection pipe of the above, connect the condenser of the low boiling point gas to the collection pipe, at the lower end of the descending path of the circulation path,
A power generation device utilizing waste heat was constructed in which a turbine of a generator was installed so as to be rotated by a fluid falling from an upper end.

According to the above configuration, when the low-boiling medium vaporized by the heat exchanger is ejected into the fluid from the outlet at the lower end into the rising path of the circulation path, in addition to the force of the ejection,
The fluid flows upward and rises due to the rise due to the buoyancy of the bubbles, and falls on the descending path at the upper end, whereby the potential energy rotates the turbine of the generator.

[0008] The low-boiling gas that has finished the work of lifting the fluid in this way is recovered by the condenser through a recovery pipe and supplied again to the heat exchanger as a low-boiling liquid, so that it is vaporized and then returned to the fluid in the circulation path. Do the lifting job. Therefore, the low-boiling gas does not necessarily require a high pressure and does not leak during circulation. Even when the auxiliary power generation device is provided (claim 2), since a low-boiling gas having a lower pressure after work is used, even if the airtight structure is simple, no leakage occurs.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, examples of a heat medium 10 passing through a heat exchanger 1 include oils (eg, lubricating oil, engine oil), hot air and the like, in addition to hot water accompanied by waste heat. it can. The form of the heat exchanger 1 between the heat medium 10 and the low-boiling liquid is also various, and the form is not particularly limited. In addition, circulation route 3
As for the fluid 12 filled in the oil, other than water, oils,
Powders, granules and the like can also be used.

The structure of the condenser 7 is not particularly limited as long as it can convert a low-boiling medium from a gas to a liquid.
The heat is condensed by taking in cold heat from the outside, or both are used in combination. Examples of the cold heat include snow, wind, river water and sea water.

[0011]

As described above, according to the present invention, unlike the case where the turbine is rotated by the pressure of the vaporization of the low-boiling medium, the fluid is lifted by utilizing the buoyancy of the bubbles to reduce the potential energy. Since the energy is converted into electric energy, it is not always necessary to increase the pressure of the low-boiling medium, and the leakage of the low-boiling medium can be prevented without providing an airtight wall. In addition, there is an excellent effect that the maintenance can be easily performed and the cost can be reduced. Further, it is possible to use even low waste heat, can be widely applied to industry, and can efficiently convert to electric energy.

[0012]

Next, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows a power generation apparatus utilizing waste heat, for example, in the case of using hot water as waste heat from a nuclear power plant. The heat medium 10 is used to vaporize a low-boiling liquid. The heat exchanger 1 for passing the waste heat hot water as the fluid and the circulation path 3 of the water as the fluid 12 are arranged in parallel.
And a condensing device 7 for liquefying a low-boiling-point gas from the circulation path 3 to the heat exchanger 1.

The heat exchanger 1 mainly includes a tank 8 through which hot water passes, and a supply pipe 9 for supplying a low-boiling liquid from the condenser 7 to the upper end thereof.
A low-boiling-point gas supply pipe 13 is connected from the lower end to the circulation path 3. Also,
The lower end of the tank 8 is connected to a waste heat hot water discharge pipe 15 from the nuclear power plant, and the upper end is connected to a waste water pipe 17 of heat exchanged water. Therefore, the heat-absorbing pipe 11 is heated most at the lower end near the outlet of the discharge pipe 15, so that the low-boiling liquid evaporates. In addition, heat absorbing pipe 11
Is coolest at the upper end, and the waste heat hot water in the tank 8 is cooled to a temperature of about seawater and returned to the sea by the wastewater pipe 17, so that the environment of the sea is not harmed.

The circulation path 3 for the fluid 12 is composed of a vertically long circulation pipe composed of an ascending path 19a and a descending path 19b, which is filled with water as the fluid 12 unsatisfactorily. The outlet 21 of the air supply pipe 13 projects upward and inward. Therefore, when the low-boiling-point gas is ejected from the outlet 21 and the bubbles 23 rise, the fluid 12 flows upward. The turbine 25 of the generator 5 is rotated. In addition, ascending road 19a
The suction force caused by the rise of the fluid 12 at the bottom reaches the lower end of the descending passage 19b, so that the water level P is maintained at the lower end by the negative pressure, and the space above the lower end becomes the falling space of the fluid 12, and the predetermined drop H Is obtained. The head H is set to be much larger than the height of the heat exchanger 1.

An air chamber 20 is provided at the upper end of the circulation path 3, and a low-boiling gas recovery pipe 22 is opened as an outlet there.
An auxiliary power generation device 23 that utilizes exhaust power is provided between the recovery pipe 22 and the condenser 7. Auxiliary power generator 23
Is for blowing a low-boiling gas to the turbine 27 to convert its rotational force into electric energy.
It is sent to the condenser 7 by 9 and is used as a part of the power of the compressor for condensing the low-boiling gas into a liquid.

FIG. 2 shows another embodiment. In this case, the waste heat hot water 10 in the tank 8 and the heat absorbing pipe 11 are used.
Not only that, the ascending path 19a and the descending path 19b are also heated, and their lower ends are inserted into the tank 8. In this case, since the water as the fluid 12 is heated by the warm water 10 of the waste heat, the air supply pipe 13
Even if an unvaporized low-boiling liquid is ejected from the liquid, the liquid is vaporized in the ascending path 19a, and the number of bubbles 23 explosively increases, and as a result, the upstream of the water 12 in the ascending path 19a gains momentum. become. Reference numeral 30 denotes a preliminary heat exchanger that easily condenses the low-boiling gas reaching the condenser 7 in advance and cools it with water from a river or the like.

[Brief description of the drawings]

FIG. 1 is an explanatory cross-sectional view showing a power generator using waste heat according to the present invention.

FIG. 2 is an explanatory cross-sectional view of a power generator using waste heat showing another embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Heat exchanger 3 Circulation pipe 5 Generator 7 Condenser 10 Heat medium 12 Fluid 21 Outlet 22 Recovery pipe 25 Turbine

Claims (2)

[Claims] 1. A heat exchanger for evaporating a low-boiling liquid from a condenser in a heat medium of waste heat to vaporize, and a vertical rising path and a descending path of the fluid. A vertically long circulation path filled with the filling is provided, and a gas supply pipe for the gas is provided at the lower end of the ascending path so that the low-boiling gas vaporized by the heat exchanger can flow the fluid in the ascending path upward. Open upward, open a low-boiling gas recovery pipe at the upper end of the circulation path, connect the low-boiling gas condenser to the recovery pipe, and drop from the upper end to the lower end of the descending path of the circulation path A power generator utilizing waste heat, wherein a turbine of the generator is mounted so as to be rotated by a fluid. 2. A turbine of an auxiliary power generator is provided in the middle of a recovery pipe reaching a condenser so as to rotate by the pressure of a low-boiling gas, and the power of the turbine is used for the condenser. The power generation device using waste heat according to claim 1.