Micro-negative pressure gas-steam mixture ORC waste heat power generation system

Abstract

The utility model provides a micro-negative pressure gas-steam mixture ORC waste heat power generation system which comprises the following components: an ORC power generation unit which comprises a superheater, a turbine and a synchronous generator which are connected in series, the superheater is further in bypass connection with an induced draft fan, and the induced draft fan is used for establishing negative pressure and sucking a micro-negative pressure gas-steam mixture; a micro-negative-pressure gas-steam mixture heats an organic working medium in the superheater, the organic working medium enters the turbine to push the turbine to rotate, the turbine is connected with the synchronous generator through a coupler, and the turbine drives the synchronous generator to rotate to generate electricity. The low-temperature waste heat recovery system is suitable for low-temperature waste heat recovery below 100 DEG C, the system structure is simple, the investment cost is low, and micro-negative-pressure gas-steam mixture resources can be efficiently utilized.

Description

TECHNICAL FIELD

[0001] The utility model relates to industrial waste heat utilization technical field especially a kind of ORC power generation system for micro-negative pressure gas-steam mixture low-temperature waste heat recovery. BACKGROUND

[0002] Industrial waste heat resource refers to the energy that can be recycled but not fully utilized under existing technical conditions, which widely exists in low-grade waste heat resources in chemical, metallurgical, power, food, papermaking, textile and other industries. For example, the micro-negative pressure saturated steam (pressure ≤0.1 MPa, temperature ≤100℃) discharged in industrial production is difficult to utilize directly due to its low waste heat quality, containing a large amount of non-condensable gas and being in a micro-negative pressure state. Most of it is discharged through the chimney, causing energy waste and environmental problems (such as “white pollution”).

[0003] Although the existing organic Rankine cycle (ORC) technology can effectively recover low-temperature waste heat, its application is mostly concentrated in flue gas waste heat, industrial wastewater or pressurized steam media (waste heat temperature ≥100℃, pressure ≥0.1 MPa). For example:

[0004] The CN 115030792 B patent proposes a medium-low temperature flue gas waste heat ORC power generation technology, which needs to rely on positive pressure flue gas and multi-stage air compressor, and the system is complex and has high energy consumption;

[0005] The CN 220206416 U patent is aimed at recovering waste heat from pressurized esterification steam, but it cannot handle micro-negative pressure gas-steam mixture;

[0006] The ORC system of the CN 212774444 U patent needs the waste heat medium to have self-flowing pressure, and it cannot adapt to micro-negative pressure conditions.

[0007] The above-mentioned technologies have the following defects in recovering micro-negative pressure gas-steam mixture:

[0008] 1. Pressure limitation: the waste heat medium needs to have positive pressure to drive the flow, and it cannot adapt to micro-negative pressure environment;

[0009] 2. Non-condensable gas interference: non-condensable gas in the gas-steam mixture hinders heat exchange efficiency, and the existing system lacks effective separation means;

[0010] 3. Low waste heat utilization rate: poor adaptability to ≤100℃ low-temperature waste heat, unable to fully extract heat.

[0011] With the promotion of the national “double carbon” goal and the implementation of the “Energy Conservation and Carbon Reduction Action Plan”, there is an urgent need to develop low-grade micro-negative pressure waste heat efficient recovery technology. Therefore, an ORC system that can actively establish negative pressure, separate gas-liquid components and adapt to low-temperature conditions is needed to solve the problems of waste heat waste, condensate loss and chimney white mist pollution. UTILITY MODEL CONTENT

[0012] In view of the defects of the prior art, the utility model provides a micro negative pressure gas vapor mixture ORC waste heat power generation system, aims at solving the problems of low utilization rate of micro negative pressure gas vapor mixture waste heat, waste of condensate water and chimney white mist pollution.

[0013] To solve the above technical problems, the technical scheme adopted by the present application is:

[0014] A micro negative pressure gas vapor mixture ORC waste heat power generation system, comprising the following components:

[0015] The ORC power generation unit comprises a superheater, a turbine and a synchronous generator connected in series, wherein the superheater is further connected in parallel with an induced draft fan, and the induced draft fan is used to establish negative pressure and suck the micro negative pressure gas vapor mixture;

[0016] The micro negative pressure gas vapor mixture heats the organic working medium in the superheater, the organic working medium enters the turbine to drive the turbine to rotate, the turbine is connected with the synchronous generator through a shaft coupling, and the turbine drives the synchronous generator to rotate to generate power.

[0017] Further, it further comprises a primary heat exchange and separation unit comprising an evaporator and a condensate pump connected in series, the superheater receives the micro negative pressure gas vapor mixture at the inlet of the induced draft fan, performs primary heat exchange and separates liquid condensate water, and the evaporator receives the condensate water of the superheater to perform secondary heat exchange, and the condensate water is recycled to the original process system after being further cooled by the condensate pump.

[0018] Further, it further comprises an organic working medium cooling unit comprising a preheater, a working medium pump and a condenser connected in series; the organic working medium exhaust gas after the turbine becomes low-temperature and low-pressure organic working medium, the organic working medium exhaust gas enters the preheater and exchanges heat with the liquid organic working medium discharged by the working medium pump to further reduce the temperature; the organic working medium discharged from the preheater enters the condenser, and the organic working medium is condensed into liquid in the condenser; the liquid organic working medium is pumped and pressurized by the working medium pump to become high-pressure and low-temperature organic working medium, and then enters the preheater for preheating.

[0019] Further, it further comprises a cooling circulating system comprising a circulating water pump, a cooling tower and a water supply valve connected in series, which is used for cooling water circulation and water supply of the condenser.

[0020] Further, it further comprises a main air valve and a bypass valve; the main air valve adjusts the working medium flow of the turbine, and the bypass valve is used for emergency shutdown of the turbine.

[0021] Further, the superheater and the evaporator are arranged in an upper-lower manner, and the condensate water enters the evaporator for secondary heat exchange by gravity flow.

[0022] Further, the induced fan outlet gas water content is less than a certain value, realizing chimney white elimination.

[0023] Compared with the prior art, the micro-negative pressure gas-steam mixture ORC waste heat power generation system has the following beneficial technical effects:

[0024] High-efficiency waste heat recovery: by actively establishing negative pressure through the induced fan, breaking through the dependence of the traditional ORC system on the positive pressure of the waste heat medium, high-efficiency extraction of the waste heat of the micro-negative pressure gas-steam mixture (≤100℃) is realized, and the utilization rate of low-grade waste heat is significantly improved.

[0025] Gas-liquid separation and resource recovery: through the cascade heat exchange of the superheater and the evaporator, the condensed water in the gas-steam mixture is separated and reused to the original process system, reducing water resource waste; at the same time, low-humidity incondensable gas is discharged, eliminating the "white pollution" of the chimney.

[0026] System integration and stability: combining the preheater, bypass door and other components to optimize the ORC cycle, enhancing the adaptability of the system to waste heat fluctuations; the cooling water circulation and water supply design guarantee long-term stable operation of the system.

[0027] Environmental protection and energy saving: at the same time of power generation, reducing the heat pollution caused by direct exhaust of waste heat, reducing the power consumption of the plant, and helping the green and low-carbon transformation of enterprises.

[0028] Simple structure and economy: using compact heat exchanger layout and conventional equipment combination, reducing construction and operation cost, suitable for industrial site modification and large-scale promotion. BRIEF DESCRIPTION OF DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced as follows. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0030] Figure 1 It is a structure schematic diagram of the micro-negative pressure gas-steam mixture ORC waste heat power generation system of the present application.

[0031] 1-superheater, 2-evaporator, 3-condensed water pump, 4-induced fan, 5-preheater, 6-working medium pump, 7-turbine, 8-synchronous generator, 9-condenser, 10-circulating water pump, 11-cooling tower, 12-main air valve, 13-bypass door, 14-water supply valve DETAILED DESCRIPTION

[0032] In order to make the purposes, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0033] As shown in the drawings, Figure 1 The micro-negative pressure gas-steam mixture ORC waste heat power generation system of the present application comprises the following components:

[0034] The ORC power generation unit comprises a superheater 1, a turbine 7 and a synchronous generator 8 connected in series, wherein a draft fan 4 is further connected in parallel to the superheater 1, and the draft fan 4 is used to establish negative pressure and suck the micro-negative pressure gas-steam mixture;

[0035] The micro-negative pressure gas-steam mixture heats the organic working medium in the superheater 1, the organic working medium enters the turbine 7 to drive the turbine 7 to rotate, the turbine 7 is connected with the synchronous generator 8 through a shaft coupling, and the turbine 7 drives the synchronous generator 8 to rotate to generate power.

[0036] In the present application, the primary heat exchange and separation unit comprises an evaporator 2 and a condensate pump 3 connected in series, the superheater 1 receives the micro-negative pressure gas-steam mixture at the inlet of the draft fan 4, performs primary heat exchange and separates the liquid phase condensate water, the evaporator 2 receives the condensate water of the superheater 1 to perform secondary heat exchange, and the further cooled condensate water is recovered to the original process system through the condensate pump 3.

[0037] In the present application, the organic working medium cooling unit comprises a preheater 5, a working medium pump 6 and a condenser 9 connected in series, the organic working medium exhaust gas after the turbine 7 becomes low-temperature and low-pressure organic working medium exhaust gas, the organic working medium exhaust gas enters the preheater 5 and exchanges heat with the liquid organic working medium discharged by the working medium pump 6 to further reduce the temperature, the organic working medium discharged from the preheater 5 enters the condenser 9, the organic working medium is condensed into liquid in the condenser, the liquid organic working medium is pumped and pressurized by the working medium pump 6 to become high-pressure and low-temperature organic working medium, and then enters the preheater 5 for preheating.

[0038] In the present application, the cooling circulating system comprises a circulating water pump 10, a cooling tower 11 and a water supply valve 14 connected in series, and is used for cooling water circulation and water supply of the condenser 9.

[0039] In the present application, the main air valve 12 and the bypass valve 13 are further included, the main air valve 12 adjusts the working medium flow of the turbine 7, and the bypass valve 13 is used for emergency shutdown of the turbine 7.

[0040] In the application, the superheater 1 and the evaporator 2 are arranged in an up-down manner, and the condensate water flows into the evaporator 2 by gravity to perform secondary heat exchange.

[0041] In the application, the water content of the gas at the outlet of the induced draft fan 4 is less than a certain value, so that the chimney is white-free.

[0042] Finally, it should be noted that: the above examples are only used to illustrate the technical solutions of the present application, but not to limit it; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing examples, or make equivalent replacement for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A micro-negative pressure gas vapor mixture ORC waste heat power generation system, characterized in that, Comprise the following components: ORC power generation unit: including superheater (1), turbine (7) and synchronous generator (8) connected in series, wherein, superheater (1) is also bypass connected with induced draft fan (4), the induced draft fan (4) is used to establish negative pressure and suction micro negative pressure gas-steam mixture; Micro negative pressure gas-steam mixture is heated in the superheater (1) organic working medium, organic working medium enters the turbine (7), and the turbine (7) is rotated, the turbine (7) is connected with the synchronous generator (8) through the shaft coupling, and the synchronous generator (8) is rotated and power generation is driven by the turbine (7).

2. The system of claim 1, wherein, Also including the first heat exchange separation unit: including evaporator (2) and condensate pump (3) connected in series, the superheater (1) receives the micro negative pressure gas-steam mixture of induced draft fan (4) inlet, carries out first heat exchange and separates liquid phase condensate water;The evaporator (2) receives the condensate water of superheater (1) and carries out secondary heat exchange, and the condensate water is recycled to the original process system through the condensate pump (3) after further cooling.

3. The system of claim 1, wherein, Also including organic working medium cooling unit: including preheater (5), working medium pump (6) and condenser (9) connected in series;Organic working medium exhaust gas becomes low temperature and low pressure organic working medium after the turbine (7), and the organic working medium exhaust gas enters the preheater (5) and exchanges heat with the liquid organic working medium discharged by the working medium pump (6), and the temperature is further reduced;The organic working medium discharged from the preheater (5) enters the condenser (9), and the organic working medium is condensed into liquid state in the condenser, and the liquid organic working medium is pumped by the working medium pump (6) to become high pressure and low temperature organic working medium, and then enters the preheater (5) for preheating.

4. The system of claim 1, wherein, Also including cooling circulating system: including circulating water pump (10), cooling tower (11) and water supply valve (14) connected in series, for cooling water circulation and water supply of condenser (9).

5. The system of claim 1, wherein, Also including main air valve (12) and bypass door (13): main air valve (12) adjusts turbine (7) working medium flow, and bypass door (13) is used for emergency shutdown of turbine (7) inlet.

6. The system of claim 1, wherein, The superheater (1) and evaporator (2) are arranged in an upper and lower position, and the condensate water enters the evaporator (2) for secondary heat exchange by gravity flow.

7. The system of claim 1, wherein, The water content of the gas at the outlet of the induced draft fan (4) is less than a certain value, and the chimney is white.

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