JPH08105305A - Absorption type rankine cycle generation apparatus - Google Patents

Abstract

PURPOSE: To use a mixture medium of ammonia and water as an operating medium of Rankine cycle for improving the design requirement for turbine pressure or the like and lower generation output amount. CONSTITUTION: A heat recovering power generation apparatus uses a mixing medium of ammonia and water as an operating medium and waste heat having a relatively low temperature as heat source. The evaporation section separates ammonia steam introduced into the turbine 1 from water in ammonia aqueous solution so that the water is again mixed with the ammonia steam emitted from the turbine 1 in a condenser 2 to send the formed ammonia aqueous solution to the evaporation section, while the water and ammonia aqueous solution moving in the opposite directions between the evaporation section 4 and the condenser 2 are subjected to heat exchange.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an absorption-type Rankine cycle power generator which effectively utilizes unused energy at a relatively low temperature (for example, 150 ° C. or lower) discharged from a factory or the like.

[0002]

2. Description of the Related Art Conventionally, as a most typical device for recovering heat from low temperature waste heat to generate electricity, FIG.
There is known an ammonia single Rankine cycle power generation device as shown in FIG. This device uses an organic medium, which is a low boiling point medium, as a working medium, for example, a single medium such as ammonia or chlorofluorocarbon, and exhaust gas discharged from the turbine 1 is cooled by cooling water C in a condenser 2 and liquefied. The liquefied ammonia solution (NH ₃ ) is supplied to the evaporator 4 such as a boiler by the liquid supply pump 3, and the waste heat H of a relatively low temperature
Is vaporized and supplied as ammonia vapor to the turbine 1, and the generator 5 driven by the turbine 1 generates electric power.

A Rankine cycle power generator using such a low boiling point medium has a temperature of 150 ° C. or lower as described above.
Usually, it is an attempt to use unused energy for human life by using an evaporator and a turbine, but the high pressure and high temperature conditions are determined from the characteristics of ammonia. That is, since the pressure of the exhaust gas from the turbine 1 is also determined by the temperature cooled by the cooling water C, it is not necessarily an appropriate medium in terms of temperature level.
The power generated by the turbine will not be greater than this.

On the other hand, although a Carina cycle similar to this Rankine cycle is also known, this cycle has a problem that the system is complicated and the target temperature is relatively high like the exhaust gas temperature level of the gas turbine.

[0005]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and its object is to use a mixed medium of ammonia and water as a working medium of Rankine cycle. However, it is another object of the present invention to provide an absorption-type Rankine cycle power generation device capable of improving design conditions such as turbine pressure and the amount of power generation output.

[0006]

That is, the absorption Rankine cycle power generator of the present invention is a heat recovery power generator in which a working medium is a mixed medium of ammonia and water and waste heat of a relatively low temperature is used as a heat source. In the evaporator, the aqueous ammonia solution is separated into ammonia vapor to be introduced into the turbine and water, and the water is mixed again with the ammonia vapor discharged from the turbine in the condenser to form the aqueous ammonia solution as described above. The liquid is sent to the evaporation section, and at the same time, the water and the ammonia solution moving between the evaporation section and the condenser in the opposite direction are heat-exchanged.

That is, the aqueous ammonia solution heated in the evaporating section by the heat source of waste heat having a relatively low temperature of 150 ° C. or lower is separated into ammonia vapor and water, and the separated water is ammonia that is exhaust gas from the turbine. Since it makes contact with the steam at the condenser, where it is cooled by cooling water, the ammonia steam is absorbed by water to form an aqueous ammonia solution, and returns to the evaporation section via the heat exchanger that exchanges heat with the water, This heat exchanger prevents heat loss and uses a mixed medium of water and ammonia as the working medium, so the condensation pressure in the condenser can be reduced, while the turbine expansion rate can be increased, and the generated output is that much. Can be made bigger.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a system diagram of an absorption-type Rankine cycle power generation device according to the present invention, and FIG. 2 is a detailed system diagram of a main part of an evaporation section of an absorption-type Rankine cycle power generation device according to the present invention. It shows with.

This power generator uses a mixed medium of ammonia and water as a working medium, and has a relatively low temperature, for example,
This is a heat recovery power generator using waste heat of 150 ° C. or less discharged from a factory or the like as a heat source, and by heating the aqueous ammonia solution with the waste heat H in the evaporation section 4 of FIG. 1, it is separated into ammonia vapor and water. ing. The separated ammonia vapor is introduced into the turbine 1 and generated by the power generator 5, while the separated water is sent to the condenser 2 via the heat exchanger 6 and discharged from the turbine 1 here. The aqueous ammonia is formed again by the mixing of the ammonia vapor and the water that absorbs the ammonia vapor that is brought into contact with the ammonia vapor and cooled by the cooling water C in the condenser 2.

This aqueous ammonia solution is returned by the liquid supply pump 3 to the evaporator 4 via the heat exchanger 6. As described above, the water moving from the evaporator 4 to the condenser 2 and the aqueous ammonia solution moving from the condenser 2 to the evaporator 4 perform heat exchange via the heat exchanger 6 in each movement. It will be.

Here, in the condenser 2, when the two media of ammonia vapor and water are mixed and mutually absorbed, absorption heat is generated, and the absorption heat is taken by the cooling water C of the condenser 2. However, the pressure associated with the mixing of the two media is
The pressure is extremely low as compared with the case of the conventional ammonia single Rankine cycle power generation device shown in FIG. This means that the heat drop between the inlet and the outlet of the turbine 1 increases, and the power generated in the turbine 1, that is, the amount of power generation increases accordingly.

An ammonia state diagram showing the relationship between pressure and enthalpy in the conventional example shown in FIG. 4 and the present invention shown in FIG. 1 will be described with reference to FIG. In the case of the conventional ammonia alone in FIG. 4, the diagrams AB, that is,
Enthalpy h from pressures of 1000 PSIA to 300 PSIA
₂ is the turbine adiabatic change, whereas in the case of the mixed medium of ammonia and water of the present invention of FIG.
Y, i.e., the enthalpy h ₁ from the pressure 800PSIA to 200PSIA becomes turbine abandon changes, it can be seen that the difference between h ₁ -h ₂ comes out in enthalpy. As a result, the heat drop in the turbine 1 is large, and the turbine expansion rate can be expanded, so that the generated output becomes large.

Here, when the ammonia aqueous solution concentration of the apparatus of FIG. 1 is set to 80%, there is a difference of 11.1 kcal / kg (adiabatic efficiency 100%) in the turbine adiabatic head shown in FIG. It is possible to effectively use the energy used. Next, the details of the evaporator 4 in FIG. 2 will be described. The evaporator 4 is composed of an evaporator 41 and a superheater 42, and the waste heat H is introduced from the superheater 42 to the evaporator 41 as indicated by the arrow. And is discarded after absorbing heat.

Further, the aqueous ammonia solution introduced into the evaporator 41 is separated here, and the separated ammonia vapor is further superheated in the superheater 42 via the steam separator 43, and then the turbine 1 Be introduced to. On the other hand, the separated water is introduced into the condenser 2 via the heat exchanger 6 and absorbs the ammonia vapor which is the exhaust gas of the turbine 1.

[0015]

As described above, according to the absorption rankine cycle power generator of the present invention, since the working medium is the mixed medium of water and ammonia, the condensation pressure in the condenser can be reduced. As a result, the turbine expansion rate increases,
The generated output becomes large.

[Brief description of drawings]

FIG. 1 is a system diagram of an absorption-type Rankine cycle power generation device according to the present invention.

FIG. 2 is a main part system diagram of an absorption-type Rankine cycle power generation device according to the present invention.

FIG. 3 is an ammonia state diagram showing changes in adiabatic expansion in the turbine of the device of the present invention and the conventional device.

FIG. 4 is a system diagram of a conventional ammonia single Rankine cycle power generation device.

[Explanation of symbols]

 1 Turbine 2 Condenser 4 Evaporator

Claims (1)

[Claims] 1. A heat recovery power generator using a mixed medium of ammonia and water as a working medium, and using waste heat of a relatively low temperature as a heat source, wherein the vaporizing section introduces an aqueous ammonia solution into a turbine. Water is separated into water, and the water is mixed again with the ammonia vapor discharged from the turbine in the condenser, and the formed aqueous ammonia solution is sent to the evaporation section, and between the evaporation section and the condenser. An absorption Rankine cycle power generator that exchanges heat between water and ammonia solution that move in opposite directions.