JPH09296706A - High-efficient power generation system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To substantially null thermal energy to be disposed of to the outside system by fully improving thermal efficiency. SOLUTION: A power generation system has processes to generate, from a medium-concentration ammonia working fluid (liquid) composed of condensed exhaust steam emitted from a turbine, a high-concentration ammonia working fluid (liquid) (which requires energy for raising the energy level for its generation), and a low-concentration ammonia working fluid (liquid). The thermal energy of the turbine exhaust steam is recovered through the absorption of its heat by the vaporization of the high-concentration ammonia working fluid, and the steam out of the high-concentration ammonia working fluid is absorbed and condensed into the low-concentration ammonia working fluid (liquid) to obtain the medium-concentration ammonia working fluid. The thermal energy generated at the time is employed to heat (vaporize) a working fluid used in the turbine and to raise the energy level in generating the high-concentration ammonia working fluid.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power generation system which uses a mixture of ammonia and water as a working fluid in a power generation system and a power generation system.

[0002]

2. Description of the Related Art A carina cycle using a mixture of ammonia and water as a working fluid is known.

[0003]

[Problems to be Solved by the Invention] At present, the superiority of the thermal efficiency of the gas turbine combined cycle (the maximum operating temperature is about 500 ° C.) using the Carina cycle is 2
Approximately 3 points (4 to 6% of the total), not many.

When the operating temperature is lower, the superiority is better than the above value, but the maximum operating temperature on the waste gas recovery side of the gas turbine combined cycle tends to be high in order to improve the thermal efficiency. Tends to be smaller.

Therefore, the present application uses a mixture of ammonia and water as a working fluid, but it is an object of the present invention to significantly improve thermal efficiency in a completely different method from the Carina cycle.

[0006]

1 is a block diagram of a first type power generation cycle according to the present application. The left side of FIG. 1 shows the flow of heat and energy on the power generation / heat energy recovery process side. Pumps and valves are omitted.

The high-concentration working fluid (mainly gas) discharged from the turbine 1 is sent to the heat exchanger 2 together with the intermediate-concentration working fluid (liquid), where the high-concentration working fluid (here, from liquid to gas). Heat) to give an intermediate concentration and condense. The condensed intermediate working fluid is sent to the separation process 4.

In the present specification, the high-concentration working fluid refers to a working fluid having a particularly high ammonia concentration, and the low-concentration working fluid refers to a working fluid having a particularly low ammonia concentration. The intermediate-concentration working fluid means a state in which the ammonia concentration is between the above two states.

The high-concentration working fluid (gas) whose heat energy is recovered by the heat exchanger 2 is absorbed by the low-concentration working fluid by the heat exchanger 3. At this time, heat of absorption and heat of condensation are generated to heat and evaporate the high-concentration working fluid sent to the turbine 1.

The low-concentration working fluid is preferable because the lower the concentration of ammonia, the higher the heating temperature can be. The higher the concentration of ammonia in the high-concentration working fluid, the higher the pressure of the steam entering the turbine, which is preferable.
Further, a high ammonia concentration can increase the pressure at the time of heat generation / condensation in the heat exchanger 3, and this directly leads to a temperature rise at that time. Therefore, the higher the ammonia concentration of the high-concentration working fluid, the more preferable. In this regard, as a reference diagram, FIG. 7 is attached with “enthalpy-concentration diagram of saturated solution (lower part: solution side, upper part: vapor side)”.

In FIG. 1, it seems that the thermal energy for heating the working fluid sent to the turbine 1 is apparently insufficient. However, since the high-concentration working fluid has a high energy level and the medium-concentration working fluid has a low energy level after mixing with the low-concentration working fluid, this difference in energy level increases the heat generation energy, and conversely the heat energy tends to remain. strong. When there is a surplus, energy can be discharged to the external system, while when there is a shortage, additional heating can be performed. In this regard, FIG. 7 can be used as a reference for understanding as described above.

In the separation process 4, a high concentration working fluid is separated and produced from the returned intermediate concentration working fluid. Next, the intermediate-concentration working fluid, which is the residual liquid, is heated to generate a low-concentration working fluid. The generated two kinds of working fluids are sent to the power generation / thermal energy recovery process side.

Highly concentrated working fluid (liquid) produced above
Has a higher energy level than the original working fluid at the same temperature. Therefore, heat energy from the outside is used as energy for this.

FIG. 5 is a block diagram of a second type power generation cycle according to the present application. The left side of FIG. 5 shows the flow of heat and energy on the power generation / heat energy recovery process side. Pumps and valves are omitted.

The intermediate-concentration working fluid (mainly gas) that has exited from the turbine 61 is partially condensed in the heat exchanger 62,
On the other hand, the remaining working fluid is combined with the intermediate concentration working fluid from the separation / heating system 64 and condensed in the heat exchanger 63.
This condensed intermediate-concentration working fluid is also separated and heated by the system 6.
Send to 4. Comparing the condensation temperatures at which the steam exiting the turbine 61 is condensed in the heat exchangers 62 and 63, the temperature in the heat exchanger 62 is higher. Further, as compared with the block diagram of the first type power generation cycle of FIG. 1, since the working fluid (intermediate concentration) of the turbine of FIG. 5 contains a large amount of water, the condensation temperature range (also referred to as the temperature between the evaporation point and the condensation point) Is wider. Therefore, heat energy is recovered in multiple stages.

The high-concentration working fluid (gas) whose heat energy is recovered by the heat exchangers 62 and 63 is absorbed by the low-concentration working fluid in the separation / heating system 64. At this time, heat of absorption and heat of condensation are generated, and used for separating and heating the working fluid. In order to increase the temperature in this case, it is similar to the system of FIG. 1 that the low concentration working fluid preferably has a low ammonia concentration and the high concentration working fluid (gas) also has a high ammonia concentration.

In the separation and heating process 64, the returned intermediate concentration working fluid is heated to separate the high concentration working fluid. Next, the intermediate-concentration working fluid, which is the residual liquid, is heated to generate a low-concentration working fluid, and further the intermediate-concentration working fluid is heated to generate a working fluid to be sent to the turbine. Then, in order to further heat (overheat) the working fluid to be sent to the turbine, heat energy from the outside is applied.

Highly concentrated working fluid (liquid) generated above
Has a higher energy level than the original working fluid at the same temperature. As the energy for this, the internal thermal energy described above is mainly used.

Comparing the first type power generation cycle (FIGS. 1 to 4) with the second type power generation cycle (FIGS. 5 and 6), the operating temperature of the second type power generation cycle is higher. The output per unit flow rate of the working fluid, which is high temperature, is higher in the second power generation cycle. In terms of applications, the type 2 power generation cycle is suitable for the bottoming cycle and the base (basic) cycle, and the type 1 power generation cycle is suitable for the bottoming cycle and the cycle for recovering low temperature (above room temperature) heat. The two types of cycles have a common part and can be combined.

【Example】

FIGS. 2, 3 and 4 show an embodiment of the type 1 power generation cycle described with reference to FIG. 1, while FIG. 6 shows an example of the type 2 power generation cycle described with reference to FIG.

FIG. 2 is an embodiment of the present application. The left side of the two-dot chain line is the power generation and thermal energy recovery process side, and the right side of the line is the separation process side that divides the working fluid into a high concentration working fluid (liquid) and a low concentration working fluid (liquid). .

The high-concentration working fluid (mainly gas) exiting from the turbine 11 is used as an intermediate-concentration working fluid (liquid) from the regulating valve 20 (hereinafter, the regulating valve regulates the pressure drop and the flow rate). It is also sent to the heat exchanger 12, where heat is transferred to the high-concentration working fluid (here, changed from liquid to gas) from the regulating valve 21 to be condensed. The working fluid condensed to an intermediate concentration is sent to the pump 18.

The high-concentration working fluid (gas) whose heat energy is recovered by the heat exchanger 12 is absorbed by the low-concentration working fluid by the heat exchanger 13. The temperature at this time is much higher than the temperature in the heat exchanger 12. The working fluid sent to the turbine 11 is heated by the absorption heat and the condensation heat at this time. This heating changes the working fluid from liquid to gas. The high-concentration working fluid sent to the turbine 11 contains a small amount of water, which causes a temperature difference (several tens of degrees Celsius) from the start of evaporation to the end of evaporation. As a result, the portion that does not evaporate in the heat exchanger 13 can be recovered and returned to the original state, or can be heated by external heat.

The intermediate-concentration working fluid sent by the pump 18 is separated into a high-concentration working fluid (gas) and an intermediate-concentration working fluid (liquid) by the separator 16 through the heat exchangers 14 and 15.
The high-concentration working fluid is liquefied through the heat exchanger 14 and the condenser 26 and is sent to the heat exchangers 12 and 13.

The intermediate working fluid (liquid) separated by the separator 16 is sent to the separator 17. The separator 17 separates the intermediate-concentration working fluid (gas) and the low-concentration working fluid (liquid). This low-concentration working fluid is sent to the heat exchanger 13 via the heat exchanger 15 and the regulating valve 23. On the other hand, this intermediate concentration working fluid (gas) is used for the heat exchangers 15, 14, and the condenser 2.
It is liquefied via 5 and recycled to the separator 16 side. Further, since this intermediate concentration working fluid has a high concentration, it can be used by mixing it in the path flowing to the heat exchanger 12 through the adjusting valve 21.

FIG. 3 is an example of the present application. The left side of the two-dot chain line is the power generation and thermal energy recovery process side, and the right side of the line is the separation process side that divides the working fluid into a high concentration working fluid (liquid) and a low concentration working fluid (liquid). .

The main differences from the embodiment of FIG. 2 are that 1) the steam supplied to the turbine can be heated (superheated), and 2) part of the thermal energy recovered from the turbine exhaust is separated from the separation process side. To use as energy for the separation process.

The mixture of the low-concentration working fluid and the high-concentration working fluid produces a large amount of heat energy because the energy level shifts to a low state. It can therefore also be devoted to the energy of the separation process.

The high-concentration working fluid (mainly gas) exiting the turbine 31 is an intermediate-concentration working fluid (liquid) from the adjusting valve 44.
In addition, the heat is transferred to the heat exchanger 32, where heat is transferred to the high-concentration working fluid (which is changed from liquid to gas) from the regulating valve 45 to be condensed. The working fluid condensed to an intermediate concentration is sent to the separation process side by the pump 41.

The high-concentration working fluid (gas) whose heat energy has been recovered by the heat exchanger 32 is used as the heat exchanger 33 and the heat exchanger 36.
Is absorbed by the low-concentration working fluid. The temperature at this time is much higher than the temperature in the heat exchanger 32. The high-concentration working fluid heated by the heat exchanger 33 becomes vapor, and the heat exchanger 35
It is overheated (heated) and enters the turbine 31.

The intermediate-concentration working fluid sent to the separation process side by the pump 41 passes through the heat exchanger 35, the pump 43, and the heat exchanger 36, and the separator 39 passes through the high-concentration working fluid (gas) and the intermediate-concentration working fluid ( Liquid) and separated. The high-concentration working fluid is liquefied through the heat exchangers 36 and 37 and sent to the heat exchangers 32 and 33.

The intermediate concentration working fluid (liquid) separated by the separator 39 is heated by the heat exchanger 38 and sent to the separator 40. The separator 40 separates the intermediate concentration working fluid (gas) and the low concentration working fluid (liquid). This low-concentration working fluid is sent to the heat exchangers 33 and 36 via the heat exchanger 38. On the other hand, this intermediate concentration working fluid is used in the heat exchangers 38 and 3
6. The same 37 is liquefied and is recycled to the separator 39 side. It should be noted that the heat energy becomes excessive and the heat exchanger 37
In the process in which the condensation is not completed in step 1, a condenser may be inserted between the heat exchanger 37 and the heat exchanger 36 to release heat energy to the outside for condensation.

In FIG. 3, a route for discarding to the outside is not shown, but as shown in FIG. 2, a condenser may be installed as necessary to release thermal energy to the outside to complete the condensation. .

The heat exchangers 34, 35, 36, 38 can heat the working fluid by receiving heat energy from the external system. Depending on the conditions, all the heat exchangers may receive heat energy from the external system, or only one heat exchanger may receive heat energy. Then, the heat energy can be transferred from the heat exchanger 36 to the heat exchanger 38 by a heat pump action.

FIG. 4 is an example of the present application. The right side of the chain double-dashed line is the same as in FIG. 3, and is omitted here. The difference from FIG. 3 on the left side of the chain double-dashed line is that the inlet to the turbine has two stages. By making the entrance to the turbine two stages, the thermal efficiency can be increased.

The high-concentration working fluid (mainly gas) exiting from the turbine 51 is an intermediate-concentration working fluid (liquid) from the adjusting valve 58.
In addition, the heat is sent to the heat exchanger 52, where heat is transferred to the high-concentration working fluid (here, changed from liquid to gas) from the regulating valve 59 to be condensed. The working fluid condensed to an intermediate concentration is sent to the separation process side by the pump 57.

The high-concentration working fluid (gas) from which the heat energy has been recovered by the heat exchanger 52 is absorbed by the low-concentration working fluid entering the regulating valve 60 by the heat exchanger 53. The temperature at this time is much higher than the temperature in the heat exchanger 32. In the heat exchanger 53, this heat heats the high-concentration working fluid sent to the turbine to convert it into steam. The high concentration working fluid sent by the pump 56 enters from the high pressure side of the turbine 51, and the remaining high concentration working fluid enters from the intermediate pressure side of the turbine 51. Then, these high-concentration working fluid vapors are further heated (superheated) by the heat exchanger 54 and then introduced into the turbine 51.

FIG. 6 shows an example of the second type power generation cycle of the present application. The left side of the chain double-dashed line is the power generation and thermal energy recovery process side, and the right side of the line is the working fluid of high concentration working fluid (liquid) and low concentration working fluid (liquid).
And the separation / heating process side for heating the high-concentration working fluid.

The intermediate-concentration working fluid (mainly gas) exiting from the turbine 71 is partially condensed in the heat exchanger 72 to transfer heat energy to the high-concentration working fluid (where liquid becomes gas), and Intermediate concentration working fluid (liquid) from the adjusting valve 88
In addition, the heat is sent to the heat exchanger 73, where heat is transferred to the high-concentration working fluid (here, changed from liquid to gas) from the regulating valve 89 to be condensed. The condensed intermediate concentration working fluid is sent to the separation / heating process side by the pump 82.

The high-concentration working fluid (gas) whose heat energy is recovered by the heat exchanger 72 is absorbed by the low-concentration working fluid by the heat exchanger 77. The temperature at this time is much higher than the temperature in the heat exchanger 72. Further, the high-concentration working fluid (gas) whose heat energy is recovered by the heat exchanger 73 is the heat exchanger 75.
Is absorbed by the low-concentration working fluid. The temperature at this time is much higher than the temperature in the heat exchanger 73. Then, even with the same condensation, the condensation temperature in the heat exchanger 72 is higher than the condensation temperature in the heat exchanger 73. This is because the working fluid (intermediate concentration) of the turbine contains water, so that the condensation temperature range (also referred to as the evaporation point to the condensation point) is widened. Therefore, heat energy is recovered in multiple stages.

A part of the intermediate-concentration working fluid sent to the separation / heating process side by the pump 82 passes through the heat exchanger 74, the pump 84, the heat exchanger 75, and is separated into a high-concentration working fluid (gas) by the separator 79. It is separated into an intermediate concentration working fluid (liquid).
The high-concentration working fluid is liquefied via the heat exchanger 75 and the heat exchanger 76 and sent to the heat exchangers 73 and 72.

The intermediate concentration working fluid (liquid) separated by the separator 79 is heated by the heat exchanger 77 and sent to the separator 81. The separator 81 separates the intermediate-concentration working fluid (gas) and the low-concentration working fluid (liquid). The low-concentration working fluid is absorbed by the heat exchangers 77,
Sent to 5. On the other hand, this intermediate concentration working fluid is used in the heat exchanger 7
7 and 75 are liquefied and recycled to the separator 79 side.

The rest of the intermediate-concentration working fluid sent to the separation / heating process side by the pump 82 is passed through the heat exchanger 74, the pump 85, the heat exchanger 75, and the heat exchanger 77, and the intermediate-concentration working fluid is separated by the separator 80. (Gas) and intermediate concentration working fluid (liquid)
And separated. The intermediate concentration working fluid (gas) is superheated (40 kg / cm ² , 400 ° C.) in the heat exchanger and sent to the turbine 71. On the other hand, the low-concentration working fluid is recycled to the separator 81 side through the adjusting valve 93.

In the process in which the heat energy becomes excessive and the condensation is not completed in the heat exchanger 76, the heat exchanger 76
A condenser may be inserted between the heat exchanger 75 and the heat exchanger 75 to release heat energy to the outside to complete the condensation.

In FIG. 6, a route for discarding to the outside is not shown, but as shown in FIG. 2, a condenser can be installed as necessary to output heat energy to the outside.

In the heat exchangers 74 and 78, the working fluid can be heated by receiving heat energy from the external system. Further, the heat exchanger 74 heats up the heat exchanger 7 by the action of the heat pump.
It is also possible to transfer heat energy to 5.

In the invention of this application, the higher the concentration of ammonia in the high-concentration working fluid, and the lower the concentration of ammonia in the low-concentration working fluid, the higher the separation temperature and the heating temperature, which are preferable. .

[0048]

INDUSTRIAL APPLICABILITY According to the present invention, in a system for generating power from thermal energy, thermal energy is recovered from turbine exhaust steam and used for heating a working fluid, so that thermal efficiency can be greatly improved. It is even possible to eliminate the heat energy that is essentially wasted. It is also possible to absorb the low-temperature heat energy of the external system and use it as heating energy.

[0049]

[Brief description of drawings]

FIG. 1 is a block diagram of a first type power generation cycle according to the present application.

FIG. 2 is an embodiment of the present invention.

FIG. 3 is an example of the present invention.

FIG. 4 is an embodiment of the present invention.

FIG. 5 is a block diagram of a second type power generation cycle according to the present application.

FIG. 6 is an example of the present invention.

FIG. 7 Enthalpy-concentration diagram of saturated solution

[Explanation of symbols]

1, 11, 31, 51, 61, 71 Turbine 2, 3, 12-15, 32-38, 52-54, 62,
63, 72-78 Heat exchanger 16, 17, 39, 40, 79-81 Separator 18, 19, 41-43, 55-57, 82-87 Pump 20-23, 44-49, 58-59, 88 ~ 93 Regulator valve 24 ~ 26 Condenser 4 Separation system 64 Separation / heating system

Claims (6)

[Claims] 1. A high-efficiency power generation system in which a working fluid comprises ammonia and water, wherein a working fluid having an intermediate concentration (hereinafter referred to as "concentration" refers to ammonia) is separated into a liquid by separating the highly concentrated working fluid in a gas state. Has a portion that separates the low-concentration working fluid from the intermediate-concentration working fluid in a liquid state, and the high-concentration working fluid (liquid) absorbs the thermal energy of the turbine exhaust steam. Is a high-efficiency power generation system characterized by being absorbed by the low-concentration working fluid to generate thermal energy, and using this thermal energy to vaporize the high-concentration ammonia working fluid entering the turbine. 2. A high-efficiency power generation system in which a working fluid is composed of ammonia and water, has a portion for separating a high-concentration working fluid from a medium-concentration working fluid in a gaseous state into a liquid, and The high-concentration working fluid (liquid) has a portion that separates the low-concentration working fluid in a liquid state, and the high-concentration working fluid (liquid) absorbs the thermal energy of the turbine exhaust steam, and the high-concentration working fluid is absorbed by the low-concentration working fluid. A high-efficiency power generation system, characterized in that heat energy is generated, and 1) the concentrated working fluid that enters the turbine is evaporated by this thermal energy, and 2) that the concentrated working fluid is separated. 3. A high-efficiency power generation system in which the working fluid comprises ammonia and water, which has a portion for separating the high-concentration working fluid from the intermediate-concentration working fluid in a gaseous state into a liquid, It has a portion that separates the low-concentration working fluid in a liquid state, supplies an intermediate-concentration working fluid (steam) to the turbine, and the high-concentration working fluid (liquid) absorbs the thermal energy of the turbine exhaust steam in multiple stages, The high-concentration working fluid is absorbed by the low-concentration working fluid to generate thermal energy, which is used for 1) energy for separating the high-concentration working fluid, and 2) for separating the low-concentration working fluid. A high thermal efficiency power generation system which is provided with energy and further 3) vaporizes at least a part of a working fluid entering a turbine. 4. The high thermal efficiency power generation system according to claim 1, wherein the working fluid entering the turbine is superheated by thermal energy from an external system. 5. The temperature for separating the high-concentration working fluid from the intermediate-concentration working fluid in the gas state is lower than the temperature for separating the low-concentration working fluid from the intermediate-concentration working fluid in the liquid state. The high efficiency power generation system according to claim 1. 6. The intermediate-concentration working fluid, which is the basis for separating the low-concentration working fluid from the intermediate-concentration working fluid in a liquid state, is a residual liquid obtained by separating the high-concentration working fluid in a gaseous state. The high efficiency power generation system according to claim 1.