阅读说明：本技术 一种提高汽轮机效率的改进朗肯循环动力系统 (Improve improvement rankine cycle power system of steam turbine efficiency ) 是由 陈坚 吴宏 于 2020-12-02 设计创作，主要内容包括：本发明涉及蒸汽动力领域,涉及一种提高汽轮机效率的改进朗肯循环动力系统,其包括加压泵、加热器、膨胀涡轮、冷凝器以及工质液,所述加压泵、加热器、膨胀涡轮、冷凝器首尾依次闭合连接构成回路,所述膨胀涡轮与发电机相连接,所述的加热器与膨胀涡轮之间设有汽汽引射增压器,加热器的出汽口与汽汽引射增压器的主引射进汽口相连接,汽汽引射增压器的出汽口与膨胀涡轮的进汽口相连接,膨胀涡轮中间级设有支路出汽口,支路出汽口与汽汽引射增压器的被引射进汽口相连接。本发明通过增加一台汽汽引射增压器,使得循环中有一部分支路的循环工质可以不用冷凝,直接被高温高压蒸汽引射加温加压,从而完成不冷凝循环,使得该改进的朗肯循环效率要比传统的朗肯循环有显著的提高。(The invention relates to the field of steam power, in particular to an improved Rankine cycle power system for improving the efficiency of a steam turbine, which comprises a pressure pump, a heater, an expansion turbine, a condenser and working medium liquid, wherein the pressure pump, the heater, the expansion turbine and the condenser are sequentially connected end to form a loop, the expansion turbine is connected with a generator, a steam ejection supercharger is arranged between the heater and the expansion turbine, a steam outlet of the heater is connected with a main ejection steam inlet of the steam ejection supercharger, a steam outlet of the steam ejection supercharger is connected with a steam inlet of the expansion turbine, a branch steam outlet is arranged at the middle stage of the expansion turbine, and the branch steam outlet is connected with an ejection steam inlet of the steam ejection supercharger. According to the invention, by adding the steam-steam injection supercharger, a part of circulating working media with branches in the cycle can be directly injected, heated and pressurized by high-temperature and high-pressure steam without condensation, so that the non-condensation cycle is completed, and the improved Rankine cycle efficiency is obviously improved compared with the traditional Rankine cycle.)

1. The utility model provides an improve rankine cycle driving system of steam turbine efficiency, includes force (forcing) pump, heater, expansion turbine, condenser and working medium liquid, force (forcing) pump, heater, expansion turbine, condenser head and the tail closed connection in proper order constitute the return circuit, expansion turbine is connected with the generator, its characterized in that: the steam-steam ejection supercharger is arranged between the heater and the expansion turbine, a steam outlet of the heater is connected with a main ejection steam inlet of the steam-steam ejection supercharger, a steam outlet of the steam-steam ejection supercharger is connected with a steam inlet of the expansion turbine, a branch steam outlet is arranged on the expansion turbine and is connected with an ejection steam inlet of the steam-steam ejection supercharger.

2. The improved rankine cycle power system for increasing turbine efficiency according to claim 1, wherein: the branch steam outlet is arranged at the middle stage of the expansion turbine.

3. The improved rankine cycle power system for increasing turbine efficiency according to claim 1, wherein: the branch steam outlet is a branch steam outlet of the expansion turbine.

4. The improved rankine cycle power system for increasing turbine efficiency according to claim 1, wherein: and a superheater is arranged between the steam ejection supercharger and the expansion turbine.

5. The improved rankine cycle power system for increasing turbine efficiency according to claim 1, wherein: the working fluid is any substance which changes from a liquid phase to a gas phase.

Technical Field

The invention relates to the field of steam power, in particular to an improved Rankine cycle power system for a steam turbine, which is characterized by no condensation in a partial working medium circulation process.

Background

Steam power cycle (rankine cycle) is a traditional power cycle, and is an external heat closed power cycle using water or organic matters as working media, plays a very important role in industrial energy supply, is used in traditional large coal-fired thermal power stations and nuclear power stations, and ships using steam as power, and is widely used in utilization of low-grade heat source energy along with the rise of organic rankine cycle in recent years. For many years, as a mature thermodynamic cycle, the existing method for improving the thermal efficiency of the cycle mainly adopts the temperature and pressure of steam, the supercritical and ultra-supercritical and even higher temperature and pressure of water steam are realized at present, the thermal efficiency of the Rankine cycle is improved, but the equipment cost of a power system is sharply increased, but the range of the improved thermal efficiency is limited.

At present, the heat conversion efficiency of a typical Rankine cycle taking water as a working medium can reach about 43% at most under the parameters of supercritical and ultra-supercritical, so that more than 57% of heat loss in the cycle is mainly loss of a large amount of latent heat of gasification in the phase change process of condensing the exhausted steam of a steam turbine into a liquid working medium in the cycle, and the heat efficiency of the whole Rankine cycle is not very high. The main purpose of condensing the steam working medium in the Rankine cycle is to efficiently pressurize the working medium in a liquid state, and because the high pressurization ratio (the pressurization ratio can reach thousands) of the working medium in the cycle adopts gas compression, the high pressurization ratio cannot bear the energy consumption, and at present, no gas compressor capable of realizing the high pressurization ratio exists in the industry.

Disclosure of Invention

The invention solves a technical problem of providing a novel improved Rankine cycle power system for improving the efficiency of a steam turbine, the system only has an improved Rankine cycle with partial condensation of a cycle working medium, and partial non-condensation of a gaseous cycle working medium, and the system passes through an ejector additionally arranged in the invention, uses high-temperature and high-pressure steam which is formed by condensation, pressurization and heat absorption as main ejection steam of the ejector, performs ejection pressurization on low-temperature and low-pressure steam exhausted by the steam turbine to generate medium-pressure steam, and turns into high-temperature and medium-pressure steam after reheating and sends the high-temperature and medium-pressure steam to the steam turbine to do work.

In order to achieve the purpose, the invention adopts the following technical scheme that the device comprises a pressure pump, a heater, an expansion turbine, a condenser and working medium liquid, wherein the pressure pump, the heater, the expansion turbine and the condenser are sequentially connected end to end in a closed manner to form a loop, and the expansion turbine is connected with a generator.

In one embodiment, the branch steam outlet is arranged in the middle stage of the expansion turbine, a steam outlet is arranged in the middle stage of the expansion turbine and serves as a branch steam outlet of the expansion turbine, and the branch steam outlet introduces steam in the middle stage of the expansion turbine into the steam jet supercharger.

In one embodiment, the branch steam outlet is a branch steam outlet of the expansion turbine, the tail steam outlet of the expansion turbine is divided into two paths, one path is connected with the steam inlet of the condenser, and the other path is connected with the injected steam inlet of the steam-steam injection supercharger.

In one embodiment, a superheater is arranged between the steam-steam ejection supercharger and the expansion turbine.

In addition, in the invention, the working fluid is any substance which changes from a liquid phase to a gas phase.

In addition, in the present invention, the heater employs a boiler.

In addition, in the present invention, the expansion turbine is a steam turbine.

Compared with the prior art, the invention has the following advantages:

the improved Rankine cycle steam power system for improving the work efficiency of the steam turbine is used for solving the main reason that the heat efficiency of the traditional Rankine cycle is low, and the steam injection supercharger is additionally arranged, so that a part of circulating working media of branches in the cycle can be directly injected, heated and pressurized by high-temperature and high-pressure steam without being condensed, and the non-condensing cycle is completed. The steam cycle of the present invention constitutes two circuits, one condensing cycle and one non-condensing cycle. In the non-condensing circulation loop, except some irreversible dissipation losses, no external heat rejection losses exist, so the circulation efficiency is very high, while the condensing circulation loop is a traditional Rankine circulation loop, and the condensing circulation loop and the traditional Rankine circulation loop are added, so the thermal efficiency of the improved Rankine cycle provided by the invention is higher than that of the traditional Rankine cycle as the whole is that only part of the circulating working medium has heat rejection losses. Therefore, the bottleneck of improving the efficiency of the traditional Rankine cycle is broken through, and the improved Rankine cycle efficiency is remarkably improved compared with the traditional Rankine cycle by determining appropriate cycle parameters and an efficient steam-steam injection supercharger.

The invention has an implementation scheme that the principle of steam extraction at the middle stage of a steam turbine, pressurization through a steam-steam ejector and overheating entering a steam turbine generator for power generation is different from the traditional interstage steam extraction reheating, interstage steam extraction working media circulated through the improved circulation are pressurized in a steam-steam ejector supercharger, and the part of the working media are circulated in a gaseous state forever and do not generate heat through condensation. In the process of reheating interstage air extraction adopted by the traditional Rankine cycle, the pressure of the working medium cannot be increased during reheating, and finally, all latent heat of gasification is required to be condensed and dissipated. Therefore, the principle of improving the efficiency of the rankine cycle of the present invention is different from the principle of the inter-stage reheating cycle, and the efficiency is higher than the efficiency of the inter-stage reheating since the latent heat of vaporization is not condensed and released.

In addition, most devices such as a steam turbine and the like in the improved Rankine cycle steam power system work in a medium-pressure environment, only part of steam is a high-pressure system, the manufacturing cost of the whole system is much lower than that of a traditional ultra-supercritical parameter power generation system, and the improved Rankine cycle steam power system has higher cost advantage and is convenient to popularize and implement.

Drawings

FIG. 1 is a schematic overall structure according to one aspect of the present disclosure;

FIG. 2 is a schematic diagram of the overall structure of another embodiment according to an aspect of the present disclosure;

in the figure: 1-a pressure pump, 2-a boiler, 3-a steam turbine, 4-a condenser, 5-a superheater, 6-a steam-steam ejection supercharger, 601-a main ejection steam inlet, 602-an ejection steam inlet, 603-a steam outlet, 7-a branch steam outlet and 8-a generator.

Detailed Description

The present invention will be further explained with reference to the embodiments, but the invention is not limited thereto, and the structures, the proportions, the sizes, and the like, which are shown in the drawings, are only used for matching with the disclosure of the specification, so as to be understood and read by those skilled in the art, and are not used for limiting the conditions under which the present invention can be implemented, so that the present invention has no technical essence, and any structural modification, changes in proportion, or adjustments in size, should still fall within the scope covered by the technical contents disclosed in the present invention without affecting the efficacy and the achievable purpose of the present invention. In addition, the terms "upper", "lower", "front", "rear" and "middle" used in the present specification are for clarity of description, and are not intended to limit the scope of the present invention, and the relative relationship between the terms and the relative positions may be changed or adjusted without substantial technical changes.

In the first embodiment, referring to fig. 1, an improved rankine cycle power system for improving efficiency of a steam turbine includes a pressure pump 1, a heater, an expansion turbine, a condenser 4 and a working fluid, where the heater in this embodiment adopts a boiler 2, the expansion turbine in this embodiment is a steam turbine 3, the working fluid is any substance that changes from a liquid phase to a gas phase, the pressure pump 1, the boiler 2, the steam turbine 3 and the condenser 4 are sequentially connected end to form a loop, the working fluid circulates in the loop, the steam turbine 3 is connected to a generator 8, a steam-steam ejector supercharger 6 is disposed between the boiler 2 and the steam turbine 3, a steam outlet of the boiler 2 is connected to a main ejector steam inlet 601 of the steam-steam ejector supercharger 6, a steam outlet 603 of the steam-steam ejector supercharger 6 is connected to a steam inlet of the steam turbine 3, a branch steam outlet 7 is disposed at an intermediate stage of the steam turbine 3, the branch steam outlet 7 is connected with an injected steam inlet 602 of the steam-steam injection supercharger 6, and a superheater 5 is arranged between the steam-steam injection supercharger 6 and the steam turbine 3.

Specifically, the invention is provided with two circulation loops, one loop is that partial steam working medium is discharged from a steam outlet of a steam turbine 3 and then enters a condenser 4 for condensation, then enters a boiler 2 for heat absorption after being pressurized by a liquid pressure pump 1 to be changed into high-temperature high-pressure steam, the steam enters a steam-steam ejection supercharger 6 for ejecting low-pressure steam discharged from a branch steam outlet 7 of the steam turbine 3, the low-pressure steam is mixed with the low-pressure steam to form medium-pressure steam, and then the medium-pressure steam is changed into high-temperature medium-pressure steam after passing through a superheater 5 and then enters the steam turbine 3 for power generation to complete one loop of circulation, and the loop can be called as a condensation; and the other loop is characterized in that part of low-pressure steam working medium discharged from a branch steam outlet 7 arranged at the middle stage of the steam turbine 3 enters a steam-steam ejection supercharger 6, is ejected by high-temperature high-pressure steam generated by the other loop and is mixed with the high-temperature high-pressure steam to form medium-pressure steam, the medium-pressure steam is changed into high-temperature medium-pressure steam after passing through a heat device 5 and enters the steam turbine 3 to do work, so that a circulation loop is completed, and the circulation working medium of the loop is not subjected to phase change condensation in the circulation process and can be called as an uncondensed. In the case of the non-condensing cycle, except for some irreversible dissipation losses, no external heat rejection losses exist, so that the cycle efficiency is very high, while the condensing cycle is a traditional Rankine cycle, and the condensing cycle and the traditional Rankine cycle are added, so that the thermal efficiency of the Rankine cycle is improved higher than that of the traditional Rankine cycle due to the fact that only part of the circulating working medium has heat dissipation losses as a whole. Therefore, the bottleneck of improving the efficiency of the traditional Rankine cycle is broken through, and the improved Rankine cycle efficiency is remarkably improved compared with the traditional Rankine cycle by determining appropriate cycle parameters and an efficient steam-steam injection supercharger.

In the second embodiment, please refer to fig. 2, because some intermediate stages of the steam turbine cannot be provided with the branch steam outlet, the branch steam outlet 7 of the first embodiment is arranged at the tail steam outlet of the steam turbine 3, the tail steam outlet of the steam turbine 3 is divided into two paths, one path is connected with the steam inlet of the condenser 4, and the other path is used as the branch steam outlet 7 and connected with the injected steam inlet 602 of the steam-injection supercharger 6. Although the pressure and the temperature of the exhaust steam coming out of the steam outlet at the tail of the steam turbine 3 are both low, the exhaust steam with the parameters directly enters the steam-jet supercharger 6 for ejection, and the parameters of the steam at the outlet of the steam-jet supercharger 6 can be dragged to lower, so that the work efficiency of the steam turbine 3 is reduced, but for the noncondensable circulation loop, except some irreversible dissipation losses, no external heat extraction loss exists, and therefore, the thermal efficiency of the improved Rankine cycle provided by the embodiment is still higher than that of the traditional Rankine cycle.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.