阅读说明：本技术 蒸汽凝液余热发电装置 (Steam condensate waste heat power generation device ) 是由 丁文瑶 赖达辉 温润娟 王伟 金政伟 张安贵 井云环 庄壮 张智敏 徐金华 颜蜀 于 2020-12-18 设计创作，主要内容包括：本发明涉及余热回收,公开了一种蒸汽凝液余热发电装置,其中,所述蒸汽凝液余热发电装置包括中压闪蒸器(1)、连接于中压闪蒸器(1)的第一凝液输出管(20)、低压闪蒸器(6)、连接于所述低压闪蒸器(6)的第二凝液输出管(15)以及分别与所述第一凝液输出管(20)和所述第二凝液输出管(15)热耦合的有机朗肯循环发电组件。通过上述技术方案,有机朗肯循环发电组件的换热件通过有机换热剂可以与第一凝液输出管中的凝液和第二凝液输出管中的凝液进行热交换,以吸收凝液中的热能,并将热能用于发电,可以充分地利用闪蒸后排出的凝液中的热量,提高了能量利用率,实现节能减排。(The invention relates to waste heat recovery and discloses a steam condensate waste heat power generation device, wherein the steam condensate waste heat power generation device comprises a medium-pressure flash evaporator (1), a first condensate output pipe (20) connected with the medium-pressure flash evaporator (1), a low-pressure flash evaporator (6), a second condensate output pipe (15) connected with the low-pressure flash evaporator (6) and an organic Rankine cycle power generation assembly thermally coupled with the first condensate output pipe (20) and the second condensate output pipe (15) respectively. Through the technical scheme, the heat exchange piece of the organic Rankine cycle power generation assembly can exchange heat with the condensate in the first condensate output pipe and the condensate in the second condensate output pipe through the organic heat exchange agent to absorb heat energy in the condensate and use the heat energy for power generation, so that heat in the condensate discharged after flash evaporation can be fully utilized, the energy utilization rate is improved, and energy conservation and emission reduction are realized.)

1. The utility model provides a steam condensate waste heat power generation device, its characterized in that, steam condensate waste heat power generation device includes medium pressure flash vessel (1), connect in first condensate output tube (20) of medium pressure flash vessel (1), low pressure flash vessel (6), connect in second condensate output tube (15) of low pressure flash vessel (6) and respectively with first condensate output tube (20) and the organic Rankine cycle power generation subassembly of second condensate output tube (15) thermal coupling.

2. The steam condensate waste heat power generation device according to claim 1, wherein the medium-pressure flash evaporator (1) is connected with a medium-pressure condensate input pipe (11), the first condensate output pipe (20) is connected with the low-pressure flash evaporator (6), and a low-pressure condensate input pipe (13) is connected beside the first condensate output pipe (20).

3. The steam condensate waste heat power generation device according to claim 2, wherein the orc power generation assembly comprises an evaporator (2) thermally coupled to the first condensate outlet pipe (20) downstream of the low-pressure condensate inlet pipe (13), a preheater (7) thermally coupled to the second condensate outlet pipe (15), a first expander (3), a first cooler (4), and a first pressure pump (5), and the evaporator (2), the first expander (3), the first cooler (4), the first pressure pump (5), and the preheater (7) are connected in sequence by pipelines to form a closed loop cycle.

4. The steam condensate waste heat power generation device according to claim 2, wherein the organic Rankine cycle power generation assembly comprises an evaporator (2), a first expander (3), a first cooler (4) and a first pressure pump (5) which are thermally coupled to the first condensate output pipe (20) downstream of the low-pressure condensate input pipe (13), and the evaporator (2), the first expander (3), the first cooler (4) and the first pressure pump (5) are connected in sequence through pipelines to form a closed loop cycle; the organic Rankine cycle power generation assembly comprises a preheater (7), a second expander (8), a second cooler (9) and a second pressure pump (10), wherein the preheater (7), the second expander (8), the second cooler (9) and the second pressure pump (10) are thermally coupled to the second condensate outlet pipe (15), and the preheater (7), the second expander (8), the second cooler (9) and the second pressure pump (10) are sequentially connected through pipelines to form a closed-loop cycle.

5. The steam condensate waste heat power generation device according to claim 1, wherein the medium-pressure flash evaporator (1) is connected with a medium-pressure condensate input pipe (11), the second condensate output pipe (15) is provided with a mixer (21), and the first condensate output pipe (20) is connected with the mixer (21).

6. The steam condensate waste heat power generation device according to claim 5, wherein the organic Rankine cycle power generation assembly comprises an evaporator (2) thermally coupled to the first condensate outlet pipe (20), a preheater (7) thermally coupled to the second condensate outlet pipe (15) downstream of the mixer (21), a first expander (3), a first cooler (4), and a first pressure pump (5), wherein the evaporator (2), the first expander (3), the first cooler (4), the first pressure pump (5), and the preheater (7) are connected in sequence by pipelines to form a closed loop cycle.

7. The steam condensate waste heat power generation device according to claim 6, wherein a low-pressure condensate input pipe (13) is connected to the first condensate output pipe (20) located at the upstream of the evaporator (2), and the first condensate output pipe (20) located between the low-pressure condensate input pipe (13) and the evaporator (2) is connected to the low-pressure flash evaporator (6) through a bypass pipeline (23).

8. The steam condensate waste heat power generation device according to claim 6, wherein the low-pressure flash evaporator (6) is connected with a low-pressure condensate input pipe (13).

9. The steam condensate waste heat power generation device according to claim 1, wherein the medium-pressure flash evaporator (1) is connected with a first steam output pipe (12), and the low-pressure flash evaporator (6) is connected with a second steam output pipe (14).

10. The steam condensate waste heat power generation device according to any one of claims 1 to 9, wherein the steam condensate waste heat power generation device is used for coal chemical steam condensate.

Technical Field

The invention relates to the field of waste heat recovery, in particular to a steam condensate waste heat power generation device.

Background

The coal chemical industry is one of industries with large low-temperature waste heat (heat source with temperature lower than 200 ℃) discharge amount. The main sources of the low-temperature waste heat of the coal chemical device are as follows: firstly, the waste heat with lower temperature is utilized by the heat of the coal chemical production; and secondly, the heat source with high and medium temperature still has thermal waste heat after being effectively utilized. Although the waste heat resources are lower in grade than high-temperature heat sources, the quantity is large, and the distribution range is wide. In the past, only the recycling of a higher-grade heat source is emphasized in the chemical field, and in addition, the limitation of weak foundation of a low-grade waste heat recycling technology is added, so that the recycling of low-temperature waste heat resources is not emphasized sufficiently.

The current common methods for recovering low-temperature waste heat mainly comprise an intermediate medium method and a flash evaporation method. The flash evaporation method mainly recovers power of low-temperature water or a steam-water mixture. When the temperature of the heat source is not high, an intermediate medium method is preferably adopted, and waste heat recovery is mainly carried out in an indirect energy conversion mode. In recent years, technologies for recovering waste heat in industrial production include adsorption refrigeration technology, lithium bromide absorption refrigeration technology, heat pipe technology, heat pump technology, organic rankine cycle technology, and the like.

Steam condensate or steam-water mixture with different temperature grades is generated in a coal chemical technology, partial heat of the steam condensate or steam-water mixture with high and medium temperature is further recovered through a flash evaporation method, the condensate with low temperature (the temperature is 80-160 ℃ usually, and the pressure is 0.3-0.6 MPa) is cooled to a certain temperature (the temperature is 40-80 ℃ usually) through an air cooler or a cooling water heat exchanger, and the treated condensate or steam-water mixture is used as boiler water of a power device. This method not only underutilizes the plant energy, but also requires the consumption of additional electricity or circulating water. And because the steam system is not adjusted in time, and the heat exchange effect of the air cooler or the circulating water heat exchanger in high-temperature weather is poor, the phenomenon that the system has to be emptied due to high pressure is caused, a large amount of clean condensate is wasted, and adverse environmental effects are brought.

In the process of preparing propylene (MTP) from methanol at 50 ten thousand tons per year, medium-pressure condensate and low-pressure condensate are respectively subjected to flash evaporation in a medium-pressure condensate flash tank and a low-pressure condensate flash tank, after partial heat is recovered, condensate at 150 ℃, 0.45MPa and 420t/h is obtained, in order to enable the condensate to meet the receiving requirement of a water treatment center, the condensate needs to be subjected to flash evaporation again through a normal-pressure flash tank, steam discharged by flash evaporation is cooled by an air cooler, and the condensate at 102 ℃ at a bottom outlet is cooled to 70 ℃ through a large amount of cooling water until the condensate is treated into desalted water in the water treatment center. The method for recovering the condensate not only does not fully utilize the heat of the condensate at 150 ℃, 0.45MPa and 420t/h, but also consumes a large amount of electricity and cooling water. When the steam system is not adjusted in time in winter, the system pressure is high, and the system needs to be emptied through a low-pressure saturated steam emptying line so as to reduce the system pressure. In summer high-temperature weather, because cooling water heat exchanger or air cooler heat transfer effect are poor, lead to system pressure high, need carry out the unloading through ordinary pressure flash tank top air cooler unloading line to reduce system pressure causes a large amount of clean lime set to be discharged in the atmosphere with the form of steam.

Disclosure of Invention

The invention aims to provide a steam condensate waste heat power generation device to solve the problem that steam condensate waste heat cannot be fully recovered

In order to achieve the above object, in one aspect, the present invention provides a steam condensate waste heat power generation apparatus, which is characterized in that the steam condensate waste heat power generation apparatus includes an intermediate-pressure flash evaporator, a first condensate output pipe connected to the intermediate-pressure flash evaporator, a low-pressure flash evaporator, a second condensate output pipe connected to the low-pressure flash evaporator, and an organic rankine cycle power generation assembly thermally coupled to the first condensate output pipe and the second condensate output pipe, respectively.

Optionally, the medium-pressure flash evaporator is connected with a medium-pressure condensate input pipe, the first condensate output pipe is connected to the low-pressure flash evaporator, and a low-pressure condensate input pipe is connected beside the first condensate output pipe.

Optionally, the organic rankine cycle power generation assembly includes an evaporator thermally coupled to the first condensate outlet pipe downstream of the low-pressure condensate inlet pipe, a preheater thermally coupled to the second condensate outlet pipe, a first expander, a first cooler, and a first pressure pump, and the evaporator, the first expander, the first cooler, the first pressure pump, and the preheater are sequentially connected by a pipeline to form a closed loop cycle.

Optionally, the organic rankine cycle power generation assembly comprises an evaporator, a first expander, a first cooler and a first pressure pump which are thermally coupled to the first condensate output pipe located downstream of the low-pressure condensate input pipe, and the evaporator, the first expander, the first cooler and the first pressure pump are connected in sequence through pipelines to form a closed loop cycle; the organic Rankine cycle power generation assembly comprises a preheater, a second expander, a second cooler and a second pressure pump, wherein the preheater, the second expander, the second cooler and the second pressure pump are thermally coupled to the second condensate output pipe and are sequentially connected through pipelines to form a closed-loop cycle.

Optionally, the medium-pressure flash evaporator is connected with a medium-pressure condensate input pipe, the second condensate output pipe is provided with a mixer, and the first condensate output pipe is connected with the mixer.

Optionally, the orc power generation assembly includes an evaporator thermally coupled to the first condensate outlet pipe, a preheater thermally coupled to the second condensate outlet pipe downstream of the mixer, a first expander, a first cooler, and a first pressure pump, and the evaporator, the first expander, the first cooler, the first pressure pump, and the preheater are connected in series via a pipeline to form a closed loop cycle.

Optionally, a low-pressure condensate input pipe is connected to the first condensate output pipe located at the upstream of the evaporator, and the first condensate output pipe located between the low-pressure condensate input pipe and the evaporator is connected to the low-pressure flash evaporator through a bypass pipeline.

Optionally, the low-pressure flash evaporator is connected with a low-pressure condensate input pipe.

Optionally, the medium-pressure flash evaporator is connected with a first steam output pipe, and the low-pressure flash evaporator is connected with a second steam output pipe.

Optionally, the steam condensate waste heat power generation device is used for coal chemical steam condensate.

Through the technical scheme, the heat exchange piece of the organic Rankine cycle power generation assembly can exchange heat with the condensate in the first condensate output pipe and the condensate in the second condensate output pipe through the organic heat exchange agent to absorb heat energy in the condensate and use the heat energy for power generation, so that heat in the condensate discharged after flash evaporation can be fully utilized, the energy utilization rate is improved, and energy conservation and emission reduction are realized.

Drawings

Fig. 1 is a schematic diagram of a steam condensate waste heat power generation device according to a first embodiment of the present invention;

fig. 2 is a schematic diagram of a steam condensate waste heat power generation device according to a second embodiment of the present invention;

fig. 3 is a schematic diagram of a steam condensate residual heat power generation device according to a third embodiment of the present invention;

fig. 4 is a schematic diagram of a steam condensate residual heat power generation device according to a fourth embodiment of the present invention;

description of the reference numerals

1-medium-pressure flash evaporator, 2-evaporator, 3-first expander, 4-first cooler, 5-first pressure pump, 6-medium-pressure flash evaporator, 7-preheater, 8-second expander, 9-second cooler, 10-second pressure pump, 11-medium-pressure condensate input pipe, 12-first steam output pipe, 13-low-pressure condensate input pipe, 14-second steam output pipe, 15-second condensate output pipe, 16-first valve, 17-second valve, 18-third valve, 19-fourth valve, 22-fifth valve and 23-bypass pipeline.

Detailed Description

The following detailed description of embodiments of the invention refers to the accompanying drawings. It should be understood that the detailed description and specific examples, while indicating the present invention, are given by way of illustration and explanation only, not limitation.

The invention discloses a steam condensate waste heat power generation device which comprises a medium-pressure flash evaporator 1, a first condensate output pipe 20 connected with the medium-pressure flash evaporator 1, a low-pressure flash evaporator 6, a second condensate output pipe 15 connected with the low-pressure flash evaporator 6 and an organic Rankine cycle power generation assembly thermally coupled with the first condensate output pipe 20 and the second condensate output pipe 15 respectively.

The medium-pressure flash evaporator 1 can carry out flash evaporation treatment on the medium-pressure condensate and separate the medium-pressure condensate to obtain low-pressure steam and low-pressure condensate; similarly, the low-pressure flash evaporator 6 can perform flash evaporation treatment on the low-pressure steam condensate and separate the low-pressure steam condensate from the low-pressure condensate to obtain low-pressure steam and low-pressure condensate; the pressure of the medium-pressure condensate may be about 3.5MPa, and the pressure of the low-pressure condensate may be about 0.5MPa, but in other embodiments, the medium-pressure condensate and the low-pressure condensate may be two other condensates with a certain pressure difference.

In this scheme, organic rankine cycle power generation subassembly includes heat transfer spare and can utilize the thermal power generation facility of steam, and the heat transfer spare can carry out the heat exchange with the lime set in the first lime set output tube 20 and the lime set in the second lime set output tube 15 through organic heat transfer agent to absorb the heat energy in the lime set, and be used for the electricity generation with heat energy, can make full use of the heat in the discharged lime set after the flash distillation, improved energy utilization, realize energy saving and emission reduction.

The medium-pressure flash evaporator 1 is connected with a medium-pressure condensate input pipe 11, the first condensate output pipe 20 is connected with the low-pressure flash evaporator 6, and the low-pressure condensate input pipe 13 is connected to the first condensate output pipe 20. Referring to fig. 1 and 2, the medium pressure flash evaporator 1 is connected with a medium pressure condensate input pipe 11, medium pressure condensate can be input into the medium pressure flash evaporator 1 through the medium pressure condensate input pipe 11, the bottom of the medium pressure flash evaporator 1 is connected with a first condensate output pipe 20, the first condensate output pipe 20 is connected with the low pressure flash evaporator 6, and a low pressure condensate input pipe 13 is further connected, low pressure condensate can be input into the first condensate output pipe 20 through the low pressure condensate input pipe 13, the first condensate output pipe 20 can input low pressure condensate into the low pressure flash evaporator 6, and a second valve 17 is arranged on the first condensate output pipe 20 to control the first condensate output pipe 20. In this embodiment, the intermediate pressure flash vessel 1 and the low pressure flash vessel 6 are operated in series, and the low pressure condensate produced in the intermediate pressure flash vessel 1 is supplied to the low pressure flash vessel 6 together with the low pressure condensate supplied from the outside.

According to a first embodiment of the present invention, referring to fig. 1, the orc power generation assembly includes an evaporator 2 thermally coupled to the first condensate outlet pipe 20 downstream of the low-pressure condensate inlet pipe 13, a preheater 7 thermally coupled to the second condensate outlet pipe 15, a first expander 3, a first cooler 4, and a first pressure pump 5, and the evaporator 2, the first expander 3, the first cooler 4, the first pressure pump 5, and the preheater 7 are sequentially connected by a pipeline to form a closed loop cycle. In the embodiment shown in fig. 1, only one closed-loop cycle is provided, forming an organic rankine cycle power generation assembly, which includes two heat exchange devices, namely an evaporator 2 and a preheater 7, where the evaporator 2 is thermally coupled to the first condensate output pipe 20 downstream of the low-pressure condensate input pipe 13 to absorb heat energy in the low-pressure condensate, so that the organic heat exchanger is evaporated to form steam, and the organic heat exchanger steam is expanded and depressurized in the first expander 3 to output mechanical energy outwards, thereby driving the generator to generate power; the organic heat exchanger steam is expanded and depressurized and then further reaches the first cooler 4 to be cooled into liquid, the first pressure pump pressurizes the liquid to provide circulating power, the heat energy of the condensate in the second condensate output pipe 15 is absorbed in the preheater 7, and then the organic heat exchanger steam enters the evaporator 2 to continuously absorb the heat energy of the condensate in the first condensate output pipe 20, so that stable circulation is formed.

The expanders mentioned above and below in this scheme may be turbo expanders or screw expanders; the cooler is a heat exchanger or an air cooler; the evaporator comprises two pipelines which are thermally coupled with each other, wherein one pipeline is used for condensing liquid, the other pipeline is used for the organic heat exchange agent, and the heat exchange between the condensing liquid and the heat exchange agent can be realized.

According to a second embodiment of the invention, the orc power generation assembly comprises an evaporator 2, a first expander 3, a first cooler 4 and a first pressure pump 5 thermally coupled to the first condensate outlet pipe 20 downstream of the low-pressure condensate inlet pipe 13, the evaporator 2, the first expander 3, the first cooler 4 and the first pressure pump 5 being connected in series by pipes to form a closed-loop cycle; the organic Rankine cycle power generation assembly comprises a preheater 7, a second expander 8, a second cooler 9 and a second pressure pump 10 which are thermally coupled to the second condensate outlet pipe 15, wherein the preheater 7, the second expander 8, the second cooler 9 and the second pressure pump 10 are sequentially connected through pipelines to form a closed-loop cycle. As shown in fig. 2, in this embodiment, the orc power generation assembly comprises two closed-loop cycles, independent with respect to each other, for the first condensate outlet conduit 20 and the second condensate outlet conduit 15, respectively; in the closed loop circulation for the first condensate output pipe 20, the organic heat exchanger in the evaporator 2 can absorb the heat energy of the condensate in the first condensate output pipe 20 to evaporate to form steam, the steam is decompressed and expanded in the first expander 3 to output mechanical work to the outside, the reduced steam is cooled to be liquid in the first cooler 4, the first pressure pump 5 provides power for the flow of the liquid, and the organic heat exchanger liquid continuously returns to the evaporator 2 to absorb the heat energy of the condensate to form stable circulation; the closed loop circulation for the second condensate outlet conduit 15 is of a similar principle to the closed loop circulation for the first condensate outlet conduit 20, and the preheater 7 is also used to absorb the heat of the condensate in the second condensate outlet conduit 15, except that the organic heat transfer agent is not substantially evaporated, and the rest will not be described again.

In addition, referring to fig. 3 and 4, the intermediate pressure flash evaporator 1 is connected to an intermediate pressure condensate inlet pipe 11, the second condensate outlet pipe 15 is provided with a mixer 21, and the first condensate outlet pipe 20 is connected to the mixer 21. A mixer 21 is connected to the second condensate outlet conduit 15 and a first condensate outlet conduit 20 is also connected to the mixer 21, so that condensate from the intermediate pressure flash vessel 1 can be mixed with condensate from the low pressure flash vessel 6 in the mixer 21.

As shown in fig. 3 and 4, the orc power generation assembly includes an evaporator 2 thermally coupled to the first condensate outlet pipe 20, a preheater 7 thermally coupled to the second condensate outlet pipe 15 downstream of the mixer 21, a first expander 3, a first cooler 4, and a first pressure pump 5, and the evaporator 2, the first expander 3, the first cooler 4, the first pressure pump 5, and the preheater 7 are connected in sequence by a pipeline to form a closed loop cycle. Referring to fig. 3 and 4, there is shown only one closed loop cycle comprising evaporator 2, first expander 3, first cooler 4, first pressure pump 5 and preheater 7, evaporator 2 being thermally coupled to first condensate outlet conduit 20 for absorbing heat energy from condensate therein, preheater 7 being thermally coupled to second condensate outlet conduit 15 downstream of mixer 21 for absorbing heat energy from mixed condensate, including condensate exiting intermediate pressure flash vessel 1 and condensate exiting low pressure flash vessel 6.

According to a third embodiment of the present invention, a low-pressure condensate inlet pipe 13 is connected to the first condensate outlet pipe 20 upstream of the evaporator 2, and the first condensate outlet pipe 20 between the low-pressure condensate inlet pipe 13 and the evaporator 2 is connected to the low-pressure flash evaporator 6 via a bypass line 23. As shown in fig. 3, a low-pressure condensate inlet pipe 13 and a bypass pipe 23 are connected to the first condensate outlet pipe 20, and the low-pressure condensate inlet pipe 13 can feed low-pressure condensate into the first condensate outlet pipe 20; the bypass line 23 is connected to the low-pressure flash evaporator 6 to transfer the condensate in the first condensate outlet line 20 to the low-pressure flash evaporator 6, and a fifth valve 22 is provided on the bypass line 23 to selectively open the bypass line 23.

According to a fourth embodiment of the invention, a low-pressure condensate inlet 13 is connected to the low-pressure flash evaporator 6. As shown in fig. 4, in contrast to the embodiment shown in fig. 3, the low-pressure condensate feed line 13 is connected directly to the low-pressure flash vessel 6, i.e. the intermediate-pressure flash vessel 1 and the low-pressure flash vessel 6 are independent of one another.

In addition, the medium-pressure flash evaporator 1 is connected with a first steam output pipe 12, and the low-pressure flash evaporator 6 is connected with a second steam output pipe 14. The first steam output pipe 12 can output the generated low-pressure steam, and a first valve 16 is arranged on the first steam output pipe 12 to control the first steam output pipe; the second vapor takeoff pipe 14 is capable of outputting low-pressure steam generated and is provided with a third valve 18 for controlling the second vapor takeoff pipe 14.

The steam condensate waste heat power generation device is used for the steam condensate in the coal chemical industry. The low-temperature waste heat condensate generated in the coal chemical industry can be treated by using the steam condensate waste heat power generation device, so that the waste heat recovery of a low-grade heat source is realized.

The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited thereto. Within the scope of the technical idea of the invention, numerous simple modifications can be made to the technical solution of the invention, including combinations of the specific features in any suitable way, and the invention will not be further described in relation to the various possible combinations in order to avoid unnecessary repetition. Such simple modifications and combinations should be considered within the scope of the present disclosure as well.