阅读说明：本技术 一种提取电厂循环水余热的管路布置系统 (Pipeline arrangement system for extracting circulating water waste heat of power plant ) 是由 冯海波 袁汉川 刘军 吴俊杰 季薇 谭茹 袁志先 张荣林 赵国亮 王雪平 潘翠翠 于 2021-11-11 设计创作，主要内容包括：本发明涉及电厂余热利用技术领域,尤其涉及一种提取电厂循环水余热的管路布置系统,其包括汽轮机凝汽器、热泵、冷却塔和循环水泵,其中,所述汽轮机凝汽器的出口通过循环冷却水回水管道接入所述冷却塔,所述冷却塔的出口经所述循环水泵通过循环冷却水供水管道与所述汽轮机凝汽器的入口连通；其中,所述汽轮机凝汽器的出口还通过余热水供水管道与所述热泵的入口连通,所述热泵的出口通过余热水回水管道接入所述冷却塔。上述管路布置系统在确保不影响循环水泵的原有出力(扬程、流量),确保循环水泵的出力满足汽轮机组各运行工况的要求,确保机组的安全稳定运行的情况下,最大限度的回收电厂排汽废热,降低电厂热耗。(The invention relates to the technical field of waste heat utilization of power plants, in particular to a pipeline arrangement system for extracting waste heat of circulating water of a power plant, which comprises a steam turbine condenser, a heat pump, a cooling tower and a circulating water pump, wherein an outlet of the steam turbine condenser is connected to the cooling tower through a circulating cooling water return pipeline, and an outlet of the cooling tower is communicated with an inlet of the steam turbine condenser through a circulating cooling water supply pipeline through the circulating water pump; the outlet of the steam turbine condenser is communicated with the inlet of the heat pump through a waste heat water supply pipeline, and the outlet of the heat pump is connected into the cooling tower through a waste heat water return pipeline. The pipeline arrangement system ensures that the original output (lift and flow) of the circulating water pump is not influenced, ensures that the output of the circulating water pump meets the requirements of each operation condition of the steam turbine unit, and furthest recovers the exhaust waste heat of the power plant and reduces the heat consumption of the power plant under the condition of ensuring the safe and stable operation of the unit.)

1. The pipeline arrangement system for extracting the waste heat of the circulating water of the power plant is characterized by comprising a steam turbine condenser (1), a heat pump (2), a cooling tower (3) and a circulating water pump (4), wherein an outlet of the steam turbine condenser (1) is connected to the cooling tower (3) through a circulating cooling water return pipeline (5), and an outlet of the cooling tower (3) is communicated with an inlet of the steam turbine condenser (1) through a circulating cooling water supply pipeline (6) through the circulating water pump (4);

the outlet of the steam turbine condenser (1) is also communicated with the inlet of the heat pump (2) through a waste hot water supply pipeline (7), and the outlet of the heat pump (2) is connected to the cooling tower (3) through a waste hot water return pipeline (8);

the pipeline arrangement system further comprises a controller, and the controller is electrically connected with the heat pump (2) and the circulating water pump (4).

2. The pipeline arrangement system for extracting the residual heat of the circulating water in the power plant according to claim 1, characterized in that the outlet of the turbine condenser (1) is provided with a first electric butterfly valve (51), and the first electric butterfly valve (51) is electrically connected with the controller; the inlet end of the residual hot water supply pipeline (7) is positioned at the downstream of the first electric butterfly valve (51).

3. The pipeline arrangement system for extracting the residual heat of the circulating water in the power plant as claimed in claim 1, wherein a second electric butterfly valve (71) is arranged on the residual heat water supply pipeline (7), and the second electric butterfly valve (71) is electrically connected with the controller.

4. The pipeline arrangement system for extracting the residual heat of the circulating water in the power plant as claimed in claim 1, wherein the residual heat water supply pipeline (7) is provided with a flow sensor, a pressure sensor and a temperature sensor which are all electrically connected with the controller.

5. The pipeline arrangement system for extracting the residual heat of circulating water in a power plant as defined in claim 1, wherein the residual heat water supply pipeline (7) is provided with a filter screen and a shut-off valve.

6. The piping arrangement system for extracting the residual heat of circulating water in power plant according to claim 1, wherein a third electric butterfly valve (81) is arranged on the residual heat water return pipe (8), and the third electric butterfly valve (81) is electrically connected with the controller.

7. Pipeline arrangement system for extracting residual heat from circulating water in power plant according to claim 1, characterized in that the outlet end of the residual heat water return pipeline (8) sprays water to the water pool of the cooling tower (3) through a water distribution pipe (31).

8. A piping arrangement system for extracting the residual heat of circulating water of a power plant according to claim 7, characterized in that the water distribution pipe (31) connected to the residual heat water return pipe (8) is located at the side farthest from the outlet of the cooling tower (3).

9. The pipeline arrangement system for extracting the residual heat of the circulating water in the power plant according to any one of the claims 1 to 8, characterized in that an air inlet of the cooling tower (3) is sealed by a wind shield;

and/or a grid (41) and a gate (42) are arranged in a connecting channel between the cooling tower (3) and the circulating water pump (4).

10. The pipeline arrangement system for extracting the residual heat of the circulating water of the power plant according to any one of claims 1 to 8, wherein the number of the steam turbine condensers (1) is multiple, the outlets of the multiple steam turbine condensers (1) are respectively communicated with the corresponding circulating cooling water return pipelines (5), the residual heat water supply pipeline (7) comprises multiple residual heat water branch pipes, and the inlets of the residual heat water branch pipes are respectively communicated with the circulating cooling water return pipelines (5) in a one-to-one correspondence manner.

Technical Field

The invention relates to the technical field of waste heat utilization of power plants, in particular to a pipeline arrangement system for extracting waste heat of circulating water of a power plant.

Background

The thermal power plant takes water (steam) as a working medium, the steam needs to be condensed into water in a condenser after a steam turbine does work, and then a large amount of latent heat generated in the process is released to the environment through a cooling tower of a secondary circulation cooling system, so that a large amount of heat is lost, and nearly 50% of energy of the thermal power plant is lost. In winter, the heat pump unit is adopted to recover the heat, the heat can be used for urban central heating after the temperature is increased, the waste heat of a power plant is extracted to the maximum extent, and the heat efficiency is improved.

The heat source water (residual heat water) of the heat pump unit is circulating cooling water heated by a condenser in a power plant, and the pipeline connection of the circulating water system and the heat pump unit is originally in a series connection mode (see fig. 1). The running mode of the waste heat water system of the circulating water system series heat pump unit is as follows: an electric butterfly valve is arranged on a circulating cooling water return pipeline of the condenser to separate the pipeline. A residual heat water supply pipeline is led out from the front side of the electric butterfly valve and connected to a heat pump unit, a residual heat water return main pipe 8a led out from the heat pump unit is connected to a circulating cooling water return pipeline on the rear side of the electric butterfly valve, and residual heat water return is cooled to a central vertical shaft of a cooling tower along the circulating cooling water return pipeline of the machine. The pipeline series connection mode can reduce the initial investment of the pipeline, but the resistance of the circulating water system is increased after the circulating water system is connected with the heat pump unit in series, so that the power consumption of the circulating water pump is increased, and the annual running cost is increased. Meanwhile, the temperature and the water quantity of the circulating water are continuously changed due to the continuous change of the operation working condition of the unit, the requirement of the temperature of the waste heat water of the heat pump unit is met, and the operation working condition of the circulating water pump is continuously adjusted. This causes troubles in the actual operation in adjusting the temperature and amount of the circulating water. Secondly, under the condition that the load of the unit is increased, the circulating water pump cannot achieve the maximum output because of the increase of the system resistance, and the safe operation of the unit is influenced.

Disclosure of Invention

Technical problem to be solved

The invention provides a pipeline arrangement system for extracting waste heat of circulating water in a power plant, and aims to solve the problem that the power consumption of a circulating water pump is increased due to the fact that resistance is increased by the fact that a circulating water system is connected with a heat pump unit in series in the existing pipeline system.

(II) technical scheme

In order to achieve the above object, the piping arrangement system for extracting the waste heat of the circulating water in the power plant of the present invention comprises:

the system comprises a steam turbine condenser, a heat pump, a cooling tower and a circulating water pump, wherein an outlet of the steam turbine condenser is connected to the cooling tower through a circulating cooling water return pipeline, and an outlet of the cooling tower is communicated with an inlet of the steam turbine condenser through the circulating water pump through a circulating cooling water supply pipeline;

the outlet of the turbine condenser is also communicated with the inlet of the heat pump through a waste heat water supply pipeline, and the outlet of the heat pump is connected to the cooling tower through a waste heat water return pipeline;

the pipeline arrangement system further comprises a controller, and the controller is electrically connected with the heat pump and the circulating water pump.

Optionally, a first electric butterfly valve is arranged at an outlet of the turbine condenser, and the first electric butterfly valve is electrically connected with the controller; and the access end of the waste hot water supply pipeline is positioned at the downstream of the first electric butterfly valve.

Optionally, a second electric butterfly valve is arranged on the waste heat water supply pipeline, and the second electric butterfly valve is electrically connected with the controller.

Optionally, a flow sensor, a pressure sensor and a temperature sensor electrically connected to the controller are disposed on the waste heat water supply pipeline.

Optionally, a filter screen and a shut-off valve are arranged on the residual heat water supply pipeline.

Optionally, a third electric butterfly valve is arranged on the residual heat water return pipeline, and the third electric butterfly valve is electrically connected with the controller.

Optionally, the outlet end of the residual heat water return pipeline sprays water to a water pool of the cooling tower through a water distribution pipe.

Optionally, a water distribution pipe connected to the residual heat water returning pipe is located at a side farthest from the outlet of the cooling tower.

Optionally, the air inlet of the cooling tower is closed by a wind shield;

and/or a grating and a gate are arranged in a connecting channel between the cooling tower and the circulating water pump.

Optionally, the quantity of steam turbine condenser is the multiunit, the multiunit the export of steam turbine condenser respectively with correspond recirculated cooling water return pipe intercommunication, the surplus hot water supply pipeline includes many surplus hot water branch pipes, the incoming end of surplus hot water branch pipe respectively with recirculated cooling water return pipe one-to-one communicates.

(III) advantageous effects

The invention has the beneficial effects that: among the above-mentioned technical scheme, recirculated cooling water return pipe and waste heat water return pipe are two parallelly connected and open the pipeline of circulation simultaneously, and the pond of cooling tower has all been collected to outlet end between them, and recirculated cooling water and waste heat water mix in the pond of cooling tower promptly, consequently, can not increase recirculated cooling water return pipe's running resistance behind the increase waste heat water return pipe, do not increase the original circulating water system's of power plant resistance promptly. Moreover, the pipeline arrangement system ensures that the original output (lift and flow) of the circulating water pump is not influenced, ensures that the output of the circulating water pump meets the requirements of each operation condition of the steam turbine unit, and furthest recovers the waste heat of the exhaust steam of the power plant and reduces the heat consumption of the power plant under the condition of ensuring the safe and stable operation of the unit. Meanwhile, the cooling tower cools the waste heat water on the premise of meeting the cooling requirement of the circulating cooling water, namely meeting the operation requirement of a steam turbine condenser, so that the original circulating water system cannot be influenced by controlling the flow of the waste heat water after parallel pipelines are adopted, the operation control mode of the system is simplified, and the operation of power plant operators on the system is convenient to regulate and control.

Drawings

FIG. 1 is a schematic diagram of a prior art piping system;

FIG. 2 is a schematic structural diagram of a pipeline arrangement system for extracting the waste heat of circulating water in a power plant according to the present invention;

FIG. 3 is an elevation schematic view of a piping arrangement system for extracting the waste heat of circulating water in a power plant according to the present invention.

[ description of reference ]

1: a steam turbine condenser; 2: a heat pump; 3: a cooling tower; 4: a water circulating pump; 5: a circulating cooling water return pipeline; 6: a circulating cooling water supply pipeline; 7: a waste heat water supply pipeline; 8: residual hot water return pipeline;

31: a water distribution pipe; 41: a grid; 42: a gate; 51: a first electric butterfly valve; 71: a second electric butterfly valve; 81: a third electric butterfly valve; 8 a: the residual hot water returns to the main pipe.

Detailed Description

For the purpose of better explaining the present invention and to facilitate understanding, the present invention will be described in detail by way of specific embodiments with reference to the accompanying drawings.

The invention provides a pipeline arrangement system for extracting waste heat of circulating water in a power plant, which comprises a steam turbine condenser 1, a heat pump 2, a cooling tower 3 and a circulating water pump 4, wherein an outlet of the steam turbine condenser 1 is connected to the cooling tower 3 through a circulating cooling water return pipeline 5, and an outlet of the cooling tower 3 is communicated with an inlet of the steam turbine condenser 1 through a circulating cooling water supply pipeline 6 through the circulating water pump 4. Wherein, the export of steam turbine condenser 1 still passes through waste hot water supply pipe 7 and heat pump 2's entry intercommunication, and the export of heat pump 2 passes through waste hot water return pipe 8 and inserts cooling tower 3. In addition, the pipeline arrangement system also comprises a controller which is electrically connected with the heat pump 2 and the circulating water pump 4. The turbine condenser 1 is located in the plant of the power plant. The waste heat water supply pipeline 7 and the waste heat water return pipeline 8 can both adopt common welded pipelines, and the pipeline model can be DN1400, wherein DN is a nominal diameter.

The recirculated cooling water return pipe 5 and the residual heat water return pipe 8 are two pipelines which are connected in parallel and open the circulation simultaneously, outlet ends of the two pipelines are collected in a water tank of the cooling tower 3, namely, the recirculated cooling water and the residual heat water are mixed in the water tank of the cooling tower 3, therefore, the running resistance of the recirculated cooling water return pipe 5 cannot be increased after the residual heat water return pipe 8 is increased, and the resistance of the original circulating water system of the power plant is not increased. Moreover, the pipeline arrangement system ensures that the original output (lift and flow) of the circulating water pump 4 is not influenced, ensures that the output of the circulating water pump 4 meets the requirements of each operation condition of the steam turbine unit, and furthest recovers the exhaust steam waste heat of the power plant and reduces the heat consumption of the power plant under the condition of ensuring the safe and stable operation of the unit. Meanwhile, the cooling tower 3 cools the waste heat water on the premise of meeting the cooling requirement of the circulating cooling water, namely meeting the operation requirement of the steam turbine condenser 1, so that the original circulating water system cannot be influenced by controlling the flow of the waste heat water after the parallel pipeline is adopted, the operation control mode of the system is simplified, and the regulation and control of power plant operators on the system are facilitated.

Referring to fig. 2 again, the outlet of the turbine condenser 1 is provided with a first electric butterfly valve 51, and the first electric butterfly valve 51 is electrically connected with the controller; the inlet end of the residual heat water supply pipe 7 is located downstream of the first electric butterfly valve 51. Wherein, the butterfly plate of butterfly valve is installed in the diameter direction of pipeline. In the cylindrical channel of the butterfly valve body, the disc-shaped butterfly plate rotates around the axis at a rotation angle of 0-90 degrees, and when the disc-shaped butterfly plate rotates to 90 degrees, the valve is in a full-open state. The butterfly valve has simple structure, small volume and light weight, and is composed of a few parts. And the valve can be quickly opened and closed only by rotating 90 degrees, the operation is simple, and meanwhile, the valve has good fluid control characteristics. The butterfly valve has two sealing types of elastic sealing and metal sealing. The elastic sealing valve has sealing ring embedded in the valve body or attached to the butterfly plate. And the electric butterfly valve electrically connected with the controller is adopted, so that the flow of the pipeline can be conveniently and remotely controlled.

The waste heat water supply pipe 7 is provided with a second electric butterfly valve 71, and the second electric butterfly valve 71 is electrically connected to the controller. The residual heat water quantity passing through the heat pump 2 in parallel operation can be finely adjusted through the speed regulation of the circulating water pump 4 and the opening degree of the second electric butterfly valve 71, and the operation is convenient. In addition, a flow sensor, a pressure sensor and a temperature sensor which are electrically connected with the controller are arranged on the waste heat water supply pipeline 7 and used for measuring the total amount of the waste heat water and monitoring the pressure and the temperature of the waste heat water, and the controller controls the opening degree of the second electric butterfly valve 71, adjusts the working condition of the heat pump 2 and the like according to signals detected by the sensors.

Further, a filter screen and a shut-off valve are arranged on the residual heat water supply pipeline 7, the filter screen can filter impurities in the pipeline so as to avoid influencing the operation of the heat pump 2, the shut-off valve can be used as a standby valve, and when the second electric butterfly valve 71 does not work, the shut-off valve can be manually closed to protect the heat pump 2.

Referring to fig. 2 again, a third electric butterfly valve 81 is disposed on the residual heat water return pipe 8, the third electric butterfly valve 81 is electrically connected to the controller, and the amount of residual heat water entering the cooling tower 3 can be adjusted by the third electric butterfly valve 81. The second and third electric butterfly valves 71, 81 are similar in structure and function to the first electric butterfly valve 51. Moreover, the water distribution pipe 31 is located inside the cooling tower 3, and the outlet end of the residual heat water return pipe 8 sprays residual heat water to the water pool of the cooling tower 3 through the water distribution pipe 31. The residual hot water in the residual hot water return pipe 8 is distributed by the water distribution pipe 31 and then is fully mixed with the water in the cooling tower 3, so that the residual hot water can be ensured to be fully cooled. The water distribution pipe 31 may be a pipe having a plurality of water spray holes through which the residual heat water may be sprayed.

Further, in order to sufficiently mix the residual heat water cooled by the heat pump 2 with the circulating cooling water introduced into the cooling tower 3, the water distribution pipe 31 connected to the residual heat water return pipe 8 is located at the side farthest from the outlet of the cooling tower 3, thereby ensuring that the circulating cooling water and the residual heat water have a sufficient length and time to be mixed.

In order to prevent the water temperature of the cooling tower 3 from being too low, the air inlet of the cooling tower 3 is closed by a wind shield (not shown). In addition, as shown in fig. 3, a grille 41 and a gate 42 are provided in the connection passage between the cooling tower 3 and the circulating water pump 4, the grille 41 can filter large foreign matters to avoid affecting the operation of the circulating water pump 4, and the gate 42 can be opened or closed as required to control the operating state of the circulating water system. Wherein, the symbols in FIG. 3The numbers above indicate elevation.

In addition, referring again to fig. 2, the number of the steam turbine condensers 1 may be multiple groups, outlets of the multiple groups of steam turbine condensers 1 are respectively communicated with the corresponding recirculated cooling water return pipes 5, the residual heat water supply pipe 7 includes multiple residual heat water branch pipes, and the access ends of the residual heat water branch pipes are respectively communicated with the recirculated cooling water return pipes 5 in a one-to-one correspondence manner. Can share the cooling burden of steam turbine through 1 combined action of multiunit steam turbine condenser to guarantee that the steam turbine can normal operating, and multiunit steam turbine condenser 1 homoenergetic can provide the waste heat to heat pump 2, can obtain sufficient heat in order to guarantee heat pump 2, also can promote the utilization efficiency of waste heat.

The following describes a specific situation of the pipeline arrangement system for extracting the waste heat of the circulating water in the power plant based on the optimal implementation mode, so as to further explain the technical scheme of the invention.

Referring to fig. 2 and 3 again, two DN1800 electric butterfly valves are respectively arranged on two circulating cooling water return pipes 5 of the unit No. 2 to separate the pipelines. A DN1200 waste heat water branch pipe is led out from the downstream of each DN1800 electric butterfly valve, and the two waste heat water branch pipes are combined into a DN1400 waste heat water supply pipeline 7 which is connected to the heat pump 2. A DN1400 residual hot water return pipeline 8 is additionally arranged at the outlet of the heat pump 2, is laid in parallel along the No. 2 engine circulating cooling water return pipeline 5 and is connected to the water tank of the No. 2 engine cooling tower 3.

From the resistance of a pipeline system, the resistance of a circulating water system series heat pump waste heat water system is large, so that the power consumption of a circulating water pump 4 is increased, the whole heating period is estimated preliminarily to be 2928 hours, the running mode of the circulating water system series heat pump waste heat water system is adopted, and the power consumption of the circulating water pump of the No. 2 unit is 537 ten thousand DEG; the running mode that a circulating water system is connected with a heat pump waste heat water system in parallel is adopted, and the power consumption of the circulating water pump 4 of the No. 2 unit is 369 ten thousand DEG; the parallel connection mode can save 168 ten thousand degrees of service power compared with the series connection mode. Meanwhile, under the condition that the load of the unit is increased, the circulating water pump 4 cannot achieve the maximum output due to the increase of the system resistance, and the safe operation of the unit is influenced. In view of the two aspects, the running mode that the circulating water system is connected with the heat pump waste heat water system in parallel is adopted, so that the energy conservation and emission reduction are facilitated, and the running efficiency of the unit is improved.

Specifically, if a circulating water system is connected in series with a heat pump waste heat water system, the number of operating hours in the whole heating period is 2928 hours, the heating operation duration is 2066 hours under the working condition 1, one pump operates at a high speed, and the power of a water pump motor is 1700 kW/pump; under the working conditions of 2 and 3, the heating operation lasts 862 hours, the two pumps operate at low speed, and the power of the water pump motor is 1076 kW/unit. The power consumption is 2066 × 1700+862 × 1076 × 2, 5367224, 537 ten thousand degrees. Wherein, the working condition 1: the peak period of heat supply (the outdoor environment temperature is less than or equal to 2 ℃); working condition 2: the initial stage and the final stage of heat supply (the outdoor environment temperature is more than or equal to 5 ℃); working condition 3: the heat supply transition period (the outdoor environment temperature is 3-4 ℃).

If the operation mode that a circulating water system is connected with a heat pump waste heat water system in parallel is adopted, the operation hours in the whole heating period are 2928 hours, the heating operation duration hours are 2066 hours under the working condition 1, one pump operates at low speed, and the power of a water pump motor is 1076 kW/pump; under the working conditions of 2 and 3, the heating operation lasts 862 hours, one pump operates at high speed, and the power of a water pump motor is 1700 kW/unit. The power consumption is 2066 × 1076+862 × 1700 ≈ 3688416 ≈ 369 ten thousand kilowatt-hour power. Because the No. 2 unit can meet the requirement when one circulating water pump operates in the middle heating period in the heating season, the heat pump system does not need to be provided with a waste heat water booster pump. And the parallel connection mode can save 168 ten thousand degrees of service power compared with the series connection mode, and if the variable frequency control of the water pump is adopted, the energy-saving effect is better.

In the description of the present invention, it is to be understood that the terms "first", "second" and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implying any number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium; either as communication within the two elements or as an interactive relationship of the two elements. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the present invention, unless otherwise expressly stated or limited, a first feature may be "on" or "under" a second feature, and the first and second features may be in direct contact, or the first and second features may be in indirect contact via an intermediate. Also, a first feature "on," "above," and "over" a second feature may be directly or obliquely above the second feature, or simply mean that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the second feature, or may simply mean that the first feature is at a lower level than the second feature.

In the description herein, the description of the terms "one embodiment," "some embodiments," "an embodiment," "an example," "a specific example" or "some examples" or the like, means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.

Although embodiments of the present invention have been shown and described above, it should be understood that the above embodiments are illustrative and not restrictive, and that those skilled in the art may make changes, modifications, substitutions and alterations to the above embodiments without departing from the scope of the present invention.