CN-117167805-B - Combined heat supply system of plant-level cogeneration unit and operation method thereof

CN117167805BCN 117167805 BCN117167805 BCN 117167805BCN-117167805-B

Abstract

The invention belongs to the technical field of cogeneration, and discloses a plant-level cogeneration unit combined heat supply system and an operation method thereof; the plant-level cogeneration unit combined heat supply system comprises a first ejector, a second ejector, a heat storage heat exchanger, a heat storage device, a first ejector heater, an absorption heat pump, a peak heater, a compression heat pump and a basic heater group. According to the invention, heat supply network water is subjected to step heating in the basic heater group, the first ejector heater, the absorption heat pump and the peak heater, then heat exchange loss is reduced, energy utilization efficiency is improved, low-temperature waste heat is fully utilized by adopting the basic heater group, the ejectors and the heat pump which are connected in series, consumption of high-grade steam is reduced, heat supply cost is reduced, heat storage technology and compression heat pump are adopted for auxiliary heat supply, heat supply requirements can still be met when a power plant participates in power grid peak regulation, and heat supply capacity and heat supply flexibility of the power plant are improved.

Inventors

ZHU CHAO
XUE CHEN
SHI PENG
LI HUA
WANG ZHU
LI XUDONG
ZHENG GUOLIANG
BAI HUAN
ZHAO JIA
DONG LE
LIU MING
ZHAO LONG
YU XIANG
ZHANG TUO
XIN YAFEI
GUO ANXIANG
XIE ZHENXUE

Assignees

国网陕西省电力有限公司电力科学研究院
国网(西安)环保技术中心有限公司

Dates

Publication Date: 20260508
Application Date: 20231012

Claims (9)

1. The combined heat supply system of the plant-level cogeneration unit is characterized by comprising a first ejector (1), a second ejector (2), a heat storage heat exchanger (3), a heat storage device (4), a first ejector heater (5), an absorption heat pump (6), a peak heater (7), a compression heat pump (8) and a basic heater group (18), The cold side fluid outlet of the basic heater group (18) is divided into two paths, one path is communicated with the cold side fluid inlet of the first ejector heater (5), and the other path is communicated with the cold side fluid inlet of the compression heat pump (8); The injection fluid inlet of the first ejector (1), the low-temperature heat source end inlet of the evaporator of the absorption heat pump (6) and the low-temperature heat source end inlet of the evaporator of the compression heat pump (8) are respectively communicated with the steam exhaust main pipes of the plurality of heat supply units; The power fluid inlet of the first ejector (1), the power fluid inlet of the second ejector (2), the hot side fluid inlet of the peak heater (7) and the hot side fluid inlet of the heat storage heat exchanger (3) are respectively communicated with the heat supply steam extraction main pipes of the plurality of heat supply units; The outlet of the first ejector (1) is divided into two paths, one path is communicated with the steam inlet of the first ejector heater (5), the other path is communicated with the injection fluid inlet of the second ejector (2), the outlet of the second ejector (2) is communicated with the driving steam inlet of the absorption heat pump (6), the cold side fluid outlet of the first ejector heater (5) is communicated with the cold side fluid inlet of the absorption heat pump (6), the cold side fluid outlet of the absorption heat pump (6) is communicated with the cold side fluid inlet of the peak heater (7), and the cold side fluid outlet of the compression heat pump (8) is communicated with the cold side fluid inlet of the peak heater (7); the heat storage medium inlet of the heat storage device (4) is communicated with the cold side fluid outlet of the heat storage heat exchanger (3), the heat storage medium outlet of the heat storage device (4) is communicated with the cold side fluid inlet of the heat storage heat exchanger (3), the cold side fluid outlet of the heat storage device (4) is divided into three paths, the first path is communicated with the power fluid inlet of the first ejector (1), the second path is communicated with the power fluid inlet of the second ejector (2), and the third path is communicated with the hot side fluid inlet of the peak heater (7).
2. A plant-level cogeneration unit cogeneration system according to claim 1, wherein each heater in said basic heater group (18) is in series communication with an inlet steam pressure level of from small to large.
3. A combined heat and power system for plant-level cogeneration units according to claim 1, further comprising a plurality of heating units; The heat supply extraction steam of the plurality of heat supply units is collected into the heat supply extraction steam main pipe, and the exhaust steam of the plurality of heat supply units is collected into the exhaust steam main pipe.
4. A plant-level cogeneration unit cogeneration system according to claim 1, wherein, A valve I (9) is arranged on a pipeline of the first ejector (1) communicated with the heat supply steam extraction main pipe; a second valve (10) is arranged on a pipeline, which is used for being communicated with the heat supply steam extraction main pipe, of the second ejector (2); a third valve (11) is arranged on a communicating pipeline between the heat storage device (4) and the second ejector (2); a fourth valve (12) is arranged on a communicating pipeline between the heat storage device (4) and the peak heater (7); a fifth valve (13) is arranged on a pipeline, which is used for being communicated with the heat supply steam extraction main pipe, of the peak heater (7); a sixth valve (14) is arranged on a communicating pipeline between the basic heater group (18) and the first ejector heater (5); a seventh valve (15) is arranged on a communicating pipeline between the basic heater group (18) and the compression heat pump (8); a valve No. eight (16) is arranged on a communicating pipeline between the heat storage device (4) and the first ejector (1); a nine-valve (17) is arranged on a communicating pipe of the hot side fluid inlet of the heat storage heat exchanger (3).
5. A plant-level cogeneration unit combined heat and power system according to claim 1, wherein the cold side fluid inlet of the heat storage device (4) is adapted to communicate with the make-up water lines of the plurality of heat supply units.
6. The plant-level cogeneration unit combined heat and power system according to claim 1, wherein the water drainage of the basic heater group (18), the heat storage heat exchanger (3), the first ejector heater (5), the absorption heat pump (6), the peak heater (7), the compression heat pump (8) is used for converging into the condensers of the plurality of heating units.
7. A plant-level cogeneration unit combined heat and power system according to claim 1, wherein said absorption heat pump (6) is of a first type.
8. A method of operating a cogeneration unit cogeneration system of claim 1, wherein, In the plant-level combined heat and power cogeneration unit combined heat supply system, a first valve (9) is arranged on a pipeline which is used for being communicated with a heat supply steam extraction main pipe, a second valve (10) is arranged on a pipeline which is used for being communicated with the heat supply steam extraction main pipe of the second ejector (2), a third valve (11) is arranged on a communicating pipeline of the heat storage device (4) and the second ejector (2), a fourth valve (12) is arranged on a communicating pipeline of the heat storage device (4) and the peak heater (7), a fifth valve (13) is arranged on a pipeline which is used for being communicated with the heat supply steam extraction main pipe of the peak heater (7), a sixth valve (14) is arranged on a communicating pipeline of the basic heater group (18) and the first ejector heater (5), a seventh valve (15) is arranged on a communicating pipeline of the basic heater group (18) and the compression heat pump (8), a fourth valve (12) is arranged on a communicating pipeline of the heat storage device (4) and the first ejector (1), and a ninth valve (16) is arranged on a heat storage fluid inlet of the heat storage device (17); When the outlet steam flow of the heat supply and steam extraction main pipe meets the requirements of the first ejector (1), the second ejector (2), the peak heater (7) and the heat storage heat exchanger (3), the first valve (9), the second valve (10), the fifth valve (13), the ninth valve (17) and the sixth valve (14) are opened, the outlet steam of the heat supply and steam extraction main pipe enters the first ejector (1), the second ejector (2), the peak heater (7) and the heat storage heat exchanger (3), the outlet steam of the steam extraction main pipe is ejected into the first ejector heater (5) through the first ejector (1) to release heat, the outlet steam of the first ejector (1) is ejected into the absorption heat pump (6) through the second ejector (2) to release heat, the heat network backwater sequentially enters the heaters of the basic heater group (18) to be heated, the absorption heat pump (6) and the heat pump main pipe is sequentially stepped in the first ejector heater (5), the peak heater (7) to release heat, and the heat is extracted from the heat storage main pipe after the heat is supplied to the heat storage main pipe, and the outlet steam from the heat storage device (4) enters the heat storage heat exchanger.
9. The method of operation of claim 8, further comprising the steps of: When the steam flow of the outlets of the heat supply and steam extraction main pipes of the power plant participating in the peak regulation of the power grid cannot meet the requirements of the first ejector (1), the second ejector (2) and the peak heater (7), the ninth valve (17), the eighth valve (16), the third valve (11) and the fourth valve (12) are opened, the supplementing water enters the heat storage device (4) to be heated and then supplements the steam flow of the requirements of the first ejector (1), the second ejector (2) and the peak heater (7), when the heat stored in the heat storage device (4) cannot meet the heat supply requirements, the seventh valve (15) is opened, and part of the outlet fluid of the basic heater group (18) enters the compression heat pump (8) to absorb heat and then enters the peak heater (7) to absorb heat so as to meet the external heat supply requirements.

Description

Combined heat supply system of plant-level cogeneration unit and operation method thereof Technical Field The invention belongs to the technical field of cogeneration, and particularly relates to a plant-level cogeneration unit combined heat supply system and an operation method thereof. Background At present, the traditional thermal power is required to bear the tasks of peak regulation, frequency modulation and the like for guaranteeing the stable operation of a power grid along with the high-proportion large-scale grid-connected power generation of renewable energy sources such as wind, light and the like, the thermal power is gradually converted from main energy sources to basic energy sources, and meanwhile, the concentrated heat consumption demands such as resident heating and the like are rapidly increased along with the continuous promotion of industrialization and town processes, so that the thermal power unit is forced to develop in the directions of large thermoelectric ratio and high flexibility. In view of the above, the new challenge of the cogeneration technology is to ensure the heating and heat supply requirements while meeting the peak shaving requirements of the power grid, however, the existing cogeneration technical scheme has low energy utilization efficiency and poor heat supply flexibility, and the development of a new cogeneration scheme to improve the peak shaving capability of the power plant in the power grid has important significance. Disclosure of Invention The invention aims to provide a plant-level cogeneration unit combined heat supply system and an operation method thereof, which are used for solving one or more technical problems. The technical scheme provided by the invention can fully recover low-temperature waste heat in the system, can meet the peak shaving requirement of the power grid, and simultaneously ensure the heating and heat supply requirement, and has higher energy utilization efficiency and better heat supply flexibility. In order to achieve the above purpose, the invention adopts the following technical scheme: The invention provides a combined heat supply system of a factory-level cogeneration unit, which comprises a first ejector, a second ejector, a heat storage heat exchanger, a heat storage device, a first ejector heater, an absorption heat pump, a peak heater, a compression heat pump and a basic heater group, wherein the first ejector is connected with the heat storage heat exchanger, The cold side fluid outlet of the basic heater group is divided into two paths, one path is communicated with the cold side fluid inlet of the first ejector heater, and the other path is communicated with the cold side fluid inlet of the compression heat pump; The injection fluid inlet of the first ejector, the low-temperature heat source end inlet of the evaporator of the absorption heat pump and the low-temperature heat source end inlet of the evaporator of the compression heat pump are respectively communicated with the steam exhaust main pipes of the heat supply units; The power fluid inlet of the first ejector, the power fluid inlet of the second ejector, the hot side fluid inlet of the peak heater and the hot side fluid inlet of the heat storage heat exchanger are respectively communicated with the heat supply steam extraction main pipes of the plurality of heat supply units; The outlet of the first ejector is divided into two paths, one path is communicated with the steam inlet of the first ejector heater, the other path is communicated with the injection fluid inlet of the second ejector, the outlet of the second ejector is communicated with the driving steam inlet of the absorption heat pump, the cold side fluid outlet of the first ejector heater is communicated with the cold side fluid inlet of the absorption heat pump, the cold side fluid outlet of the absorption heat pump is communicated with the cold side fluid inlet of the peak heater, and the cold side fluid outlet of the compression heat pump is communicated with the cold side fluid inlet of the peak heater; The cold side fluid outlet of the heat storage device is divided into three paths, wherein the first path is communicated with the power fluid inlet of the first ejector, the second path is communicated with the power fluid inlet of the second ejector, and the third path is communicated with the hot side fluid inlet of the peak heater. A further development of the invention consists in that in the basic heater group, the individual heaters are connected in series according to the inlet steam pressure level from small to large. The invention further improves that the invention also comprises a plurality of heat supply units; The heat supply extraction steam of the plurality of heat supply units is collected into the heat supply extraction steam main pipe, and the exhaust steam of the plurality of heat supply units is collected into the exhaust steam main pipe. A further improvement of the present inve