WO2022056990A1

WO2022056990A1 - Combined highly-efficient compression heat pump energy storage and peak regulation system and method for use with thermal power plant

Info

Publication number: WO2022056990A1
Application number: PCT/CN2020/121826
Authority: WO
Inventors: 姬海民; 徐党旗; 周飞; 徐梦茜; 李文锋; 申冀康; 董方奇
Original assignee: 西安热工研究院有限公司; 西安西热锅炉环保工程有限公司
Priority date: 2020-09-18
Filing date: 2020-10-19
Publication date: 2022-03-24
Also published as: CN111964035A

Abstract

A combined highly-efficient compression heat pump energy storage and peak regulation system and method for use with a thermal power plant. The system comprises a boiler (1), a turbine (5), a power generator (6), a power switch (7), a compressor (8), a freon flue gas heat exchanger (9), a condensing heat exchanger (10), an air compressor (11), a throttle valve (12), an evaporative heat exchanger (13), an output pipe, a hybrid header (24), a heating network return-water storage tank (19), and a heating network supply-water storage tank (17). The system and method can meet the requirement of flexible deep peak regulation of a thermal power plant unit. Moreover, the invention is safe, and has economic benefits.

Description

A thermal power plant coupled high-efficiency compression heat pump energy storage peak regulation system and method

technical field

The invention belongs to the field of deep peak regulation of thermal power plants, and relates to a thermal power plant coupled high-efficiency compression heat pump energy storage peak regulation system and method.

Background technique

With the changes in the national power policy in recent years, the main functions of thermal power plants have also changed at the same time, from the main power supply to participating in the deep peak regulation of the power grid. At the same time, the state has introduced a subsidy policy for in-depth peak-shaving electricity prices, which has greatly stimulated the enthusiasm of thermal power plants to carry out in-depth peak-shaving transformation of units. At present, thermal power is facing the risk of structural overcapacity, and new energy is facing great pressure to accommodate. Thermal power is bound to make way for the development of new energy. Thermal power units face deep peak regulation. For the "Three North" regions, the conflict between wind and fire during the heating period is particularly prominent. The best period of wind resources is during the winter heating period. In addition, the proportion of thermal power units in some provinces is too high, and other types of peak-shaving power sources are relatively scarce. The growing demand for heating and the continuous increase in clean energy installations have resulted in very limited space for peak shaving. Especially in Northeast China, most of the thermal power is cogeneration units, and the peak shaving capacity is only 10%, which affects the consumption of new energy and the incremental development of new energy. , so that the thermal power unit can only achieve deep peak regulation through transformation.

At present, the units participating in the deep peak shaving operation deviate from the design value for a long time, resulting in a decrease in the safety and economy of the units. Judging from the technologies adopted and the practice of transformation, the transformed units have to varying degrees the safety problems of low-load stable combustion of boilers and hydrodynamic circulation, full-load denitrification devices and low-load cooling of steam turbines, long-term low-load and rapid The flexibility of the control system when the load is variable, the problem of equipment operating cycle and life attenuation, and the thermo-decoupling of the heating unit need to be further tackled and optimized.

SUMMARY OF THE INVENTION

The purpose of the present invention is to overcome the shortcomings of the above-mentioned prior art, and to provide a thermal power plant coupled high-efficiency compression heat pump energy storage peak regulation system and method, which can meet the requirements of flexible and deep peak regulation of thermal power plants, and has Features of high safety and economy.

In order to achieve the above object, the thermal power plant coupled high-efficiency compression heat pump energy storage peak regulation system of the present invention includes a boiler, a turbine, a generator, a power switch, a compressor, a freon-flue gas heat exchanger, a condensing heat exchanger, Air compressor, throttle valve, evaporative heat exchanger, output pipeline, mixing header, heat network return water storage tank and heat network water supply water storage tank;

The high temperature superheater, low temperature superheater, economizer and SCR denitrification device are arranged in sequence in the flue gas flow direction in the tail flue of the boiler. The outlet of the high temperature superheater is connected with the inlet of the turbine, and the output shaft of the turbine is connected to the The drive shaft is connected, and the output end of the generator is connected with the compressor through the power switch;

The tail flue is provided with a smoke outlet and a smoke inlet, wherein the smoke outlet is located between the high temperature superheater and the low temperature superheater, and the outlet of the smoke outlet is communicated with the exothermic side inlet of the freon-flue gas heat exchanger. The discharge side outlet of the gas heat exchanger is communicated with the flue gas inlet, wherein the flue gas inlet is located between the economizer and the SCR denitration device;

The outlet of the compressor is connected to the inlet of the air compressor through the heat absorption side of the freon-flue gas heat exchanger and the heat release side of the condensing heat exchanger, and the outlet of the air compressor is connected to the suction side of the evaporative heat exchanger through the throttle valve. The hot side inlet is communicated, and the heat absorption side outlet of the evaporative heat exchanger is communicated with the compressor inlet;

The circulating cooling water outlet of the condenser is connected with the heat release side inlet of the evaporative heat exchanger, and the heat absorption side outlet of the evaporative heat exchanger is divided into two paths, one of which is connected with the output pipe, and the other is connected with the inlet of the mixing header Connected, the outlet of the heat network return water storage tank is connected with the inlet of the mixing header, the outlet of the mixing header is connected with the heat-absorbing side inlet of the condensing heat exchanger, and the heat-absorbing side outlet of the condensing heat exchanger is connected with the heat sink. The inlets of the network water supply storage tanks are connected.

The outlet of the exhaust gas port is connected with the inlet of the exothermic side of the freon-flue gas heat exchanger through the #1 electric gate valve and the high temperature and high pressure fan.

The outlet of the exothermic side of the freon-flue gas heat exchanger is connected with the flue gas inlet through the #2 electric gate valve.

The air compressor is a piston air compressor.

The heat-absorbing side outlet of the evaporative heat exchanger is divided into two paths after passing through the #1 electric regulating valve, one of which is connected with the output pipeline, and the other is connected with the inlet of the mixing header through the #2 electric regulating valve and the circulating water pump.

It also includes a heat network return water circulation pump and a heat network water supply circulation pump. The outlet of the heat network return water circulation pump is connected to the inlet of the heat network return water storage tank; the outlet of the heat network water supply storage tank is connected to the heat network water supply circulation pump. .

The circulating cooling water outlet of the condenser is communicated with the heat releasing side inlet of the evaporative heat exchanger through the condenser circulating water pump.

A thermal power plant coupled high-efficiency compression heat pump energy storage peak regulation method includes the following steps:

When the thermal power unit needs deep peak shaving, close the power switch to make the compressor energize and work, extract high-temperature flue gas through the exhaust port, and send it into the freon-flue gas heat exchanger for heat release, and the freon output by the compressor enters into the freon -Isobaric reheating is carried out in the flue gas heat exchanger, and the exothermic flue gas enters the tail flue, and then enters the SCR denitrification device for denitration treatment to reduce the heat absorption of the low temperature superheater and the economizer, thereby reducing the The evaporation and power generation of the boiler can realize the peak regulation of the boiler, and at the same time increase the power consumption of the plant through the operation of the compressor, reduce the electricity provided to the outside world, and realize the peak regulation of the boiler;

The high temperature and high pressure medium output from the freon-flue gas heat exchanger enters the condensing heat exchanger for heat release, and the return water of the heat network and the cooling water output from the heat release side of the evaporative heat exchanger are mixed in the mixing header and then enter the condensing heat exchange The heat is absorbed in the heat exchanger, and then stored in the water supply storage tank of the heat network; the freon output from the heat release side of the condensing heat exchanger enters the air compressor, and the high pressure is used to push the piston to convert the high-pressure air for energy storage, and then throttling After the valve is depressurized, it enters the evaporative heat exchanger to exchange heat with the circulating cooling water to absorb the low-grade heat source in the circulating cooling water;

When the demand for power generation and power supply of the thermal power unit increases, the power switch is turned off, and the boiler runs alone to generate electricity. Increase power generation.

The present invention has the following beneficial effects:

In the specific operation of the thermal power plant coupled high-efficiency compression heat pump energy storage peak regulation system and method of the present invention, when the unit needs to perform deep peak regulation, the power switch is closed, and the compressor starts to work. All the way to high temperature flue gas, and then the heat of high temperature flue gas is stored in the water supply water storage tank of the heating network through the freon-flue gas heat exchanger, condensing heat exchanger and evaporative heat exchanger to reduce the amount of steam entering the steam turbine, Then, the power generation of the generator is reduced, and at the same time, the generator provides power for the compressor, reducing the external power supply. When the demand for power generation and power supply of the thermal power unit increases, the power switch is turned off, the compressor stops working, and the boiler runs alone to generate electricity. It can increase the power generation to meet the heating demand and meet the requirements of flexible and deep peak shaving of thermal power plants. It has the characteristics of simple system, high energy utilization efficiency and great potential for deep peak shaving. It is safer and more economical. high.

Description of drawings

FIG. 1 is a schematic structural diagram of the present invention.

Among them, 1 is boiler, 2 is high temperature superheater, 3 is low temperature superheater, 4 is economizer, 5 is turbine, 6 is generator, 7 is power switch, 8 is compressor, 9 is freon-flue gas Heat exchanger, 10 is condensation heat exchanger, 11 is piston air compressor, 12 is throttle valve, 13 is evaporative heat exchanger, 14 is #1 electric gate valve, 15 is high temperature and high pressure fan, 16 is #2 electric Gate valve, 17 is the heating network water supply storage tank, 18 is the heating network water supply circulating pump, 19 is the heating network return water storage tank, 20 is the heating network return water circulating pump, 21 is the #1 electric regulating valve, 22 is the #2 electric Regulating valve, 23 is a circulating water pump, 24 is a mixing header, and 25 is a condenser circulating water pump.

detailed description

Below in conjunction with accompanying drawing, the present invention is described in further detail:

1, the thermal power plant coupled high-efficiency compression heat pump energy storage peak regulation system according to the present invention includes a boiler 1, a turbine 5, a generator 6, a power switch 7, a compressor 8, a freon-flue gas heat exchanger 9, Condensing heat exchanger 10, air compressor 11, throttle valve 12, evaporative heat exchanger 13, output pipeline, mixing header 24, heat network return water storage tank 19 and heat network water supply water storage tank 17; The flue gas flow direction in the tail flue is sequentially provided with a high temperature superheater 2, a low temperature superheater 3, an economizer 4 and an SCR denitration device. The outlet of the high temperature superheater 2 is connected with the inlet of the turbine 5, and the output shaft of the turbine 5 It is connected with the drive shaft of the generator 6, and the output end of the generator 6 is connected with the compressor 8 through the power switch 7; Between the superheaters 3, the outlet of the smoke port is communicated with the inlet of the exothermic side of the freon-flue gas heat exchanger 9, and the outlet of the exothermic side of the freon-flue gas heat exchanger 9 is communicated with the inlet of the flue gas. The gas inlet is located between the economizer 4 and the SCR denitration device; the outlet of the compressor 8 is connected to the inlet of the air compressor 11 through the heat absorption side of the freon-flue gas heat exchanger 9 and the heat release side of the condensing heat exchanger 10 The outlet of the air compressor 11 is communicated with the heat-absorbing side inlet of the evaporative heat exchanger 13 through the throttle valve 12, and the heat-absorbing side outlet of the evaporative heat exchanger 13 is communicated with the inlet of the compressor 8; the circulation of the condenser The cooling water outlet is communicated with the heat release side inlet of the evaporative heat exchanger 13 , and the heat absorption side outlet of the evaporative heat exchanger 13 is divided into two paths, one of which is connected with the output pipe, and the other is connected with the inlet of the mixing header 24 The outlet of the heat network return water storage tank 19 is communicated with the inlet of the mixing header 24, and the outlet of the mixing header 24 is communicated with the heat absorption side inlet of the condensing heat exchanger 10, and the endothermic heat of the condensing heat exchanger 10 is communicated The side outlet is communicated with the inlet of the water supply water storage tank 17 of the heat network.

The outlet of the smoke outlet is connected with the inlet of the exothermic side of the freon-flue gas heat exchanger 9 through the #1 electric gate valve 14 and the high temperature and high pressure fan 15; the outlet of the exothermic side of the freon-flue gas heat exchanger 9 is connected with the #2 electric gate valve 16 is communicated with the flue gas inlet.

The outlet of the heat-absorbing side of the evaporative heat exchanger 13 is divided into two paths after passing through the #1 electric regulating valve 21, one of which is connected to the output pipeline, and the other is the connection between the #2 electric regulating valve 22 and the circulating water pump 23 and the mixing header 24. The entrance is connected.

The present invention also includes a heat network return water circulation pump 20 and a heat network water supply circulation pump 18. The outlet of the heat network return water circulation pump 20 is communicated with the inlet of the heat network return water storage tank 19; the outlet of the heat network water supply storage tank 17 is connected to the The heating network water supply circulating pump 18 is connected.

The circulating cooling water outlet of the condenser and the heat releasing side inlet of the evaporative heat exchanger 13 are communicated through the condenser circulating water pump 25, and the air compressor 11 is a piston air compressor.

The thermal power plant coupling high-efficiency compression heat pump energy storage peak regulation method of the present invention comprises the following steps:

When the thermal power unit needs deep peak shaving, close the power switch 7 to make the compressor 8 energize and work, extract high-temperature flue gas through the exhaust gas port, and send it into the freon-flue gas heat exchanger 9 for heat release, and the output of the compressor 8 Freon enters into the Freon-flue gas heat exchanger 9 for isobaric reheating, and the exothermic flue gas enters the tail flue, and then enters the SCR denitrification device for denitration treatment to reduce the low temperature superheater 3 and save coal. The boiler 4 absorbs heat, then reduces the evaporation and power generation of the boiler 1, realizes the peak regulation of the boiler 1, and at the same time increases the power consumption of the plant through the operation of the compressor 8, reduces the electricity provided to the outside world, and realizes the peak regulation of the boiler 1;

The high temperature and high pressure medium output from the freon-flue gas heat exchanger 9 enters the condensing heat exchanger 10 for heat release, and the return water of the heat network and the cooling water output from the heat release side of the evaporative heat exchanger 13 are mixed in the mixing header 24 and then enter the The heat is absorbed in the condensing heat exchanger 10, and then stored in the water supply water storage tank 17 of the heat network; the freon output from the heat release side of the condensing heat exchanger 10 enters the air compressor 11, and the high pressure is used to push the piston to convert the high-pressure air. Store energy, and then enter the evaporative heat exchanger 13 to exchange heat with the circulating cooling water after depressurizing the throttle valve 12, so as to absorb the low-grade heat source in the circulating cooling water;

When the demand for power generation and power supply of the thermal power unit increases, the power switch 7 is turned off, and the boiler 1 operates alone to generate electricity. Pump air to increase power generation.

Example 1

The specific operation process of this embodiment is:

When the thermal power unit needs deep peak regulation, open the #1 electric gate valve 14 and #2 electric gate valve 16, start the high temperature and high pressure fan 15; close the power switch 7, make the compressor 8 energize and work; start the heat network return water circulating pump 20 and the heat network Return water circulating pump 20; start the condenser circulating water pump 25, and open the #1 electric regulating valve 21.

When the power grid requires the peak load of the unit to be 30%, the operating load of the boiler 1 can reach 40%, and the excess 10% heat and power generation are stored and efficiently utilized through the high-efficiency compression pump system, that is, the high-temperature and high-pressure fan 15 extracts 5 ~10% of the high-temperature flue gas at 600°C is sent to the freon-flue gas heat exchanger 9 for heat release, and the 2MPa, 150°C freon output by the compressor 8 enters the freon-flue gas heat exchanger 9 for isobaric regeneration. Heating to 250°C, the exothermic flue gas enters the tail flue, and then enters the SCR denitrification device for denitration treatment, so as to reduce the heat absorption of the low temperature superheater 3 and the economizer 4, thereby reducing the evaporation of the boiler 1 and power generation, and achieve peak shaving of boiler 1. On the other hand, through the operation of the compressor 8, the power consumption of the plant is increased, the power supplied to the outside world is reduced, and the peak regulation of the boiler 1 is realized;

The 250°C, 2MPa high-temperature and high-pressure medium output from the freon-flue gas heat exchanger 9 enters the condensing heat exchanger 10 for heat release, and the 45°C heat network return water and the 10°C water output from the circulating water pump 23 are placed in the mixing header 24 After mixing, it enters the condensing heat exchanger 10 to absorb heat, heats the water to 95°C and stores it in the water supply water storage tank 17 of the heat network; the 60°C, 2MPa freon output from the heat release side of the condensing heat exchanger 10 enters the air pressure In the machine 11, the high pressure is used to push the piston, and the high-pressure air is converted to store energy, and then the working fluid is adjusted to 0.1 MPa, 0 °C through the throttle valve 12, and then sent to the evaporative heat exchanger 13 for exchange with circulating cooling water. Heat to absorb the low-grade heat source in the circulating cooling water, so that the temperature of the cooling water is reduced from 25 ℃ to 10 ℃.

When the demand for power generation and power supply of the thermal power unit increases, the power switch 7 is turned off, and the boiler 1 operates alone to generate electricity. The heat supply required at this stage is supplied by the heat stored in the water supply storage tank 17 of the heating network to provide heat, reducing air extraction. Increase power generation.

In addition, it should be noted that the present invention improves the parameters of freon in the heat pump system, reduces the inlet water temperature of the condenser heat exchanger, and sets up a piston air compressor, so that the heat pump energy efficiency coefficient COP is greatly improved.

Claims

A thermal power plant coupled high-efficiency compression heat pump energy storage peak regulation system, characterized in that it comprises a boiler (1), a turbine (5), a generator (6), a power switch (7), a compressor (8), a freon - flue gas heat exchanger (9), condensing heat exchanger (10), air compressor (11), throttle valve (12), evaporation heat exchanger (13), output pipe, mixing header (24), A heat network return water storage tank (19) and a heat network water supply water storage tank (17);

A high temperature superheater (2), a low temperature superheater (3), an economizer (4) and an SCR denitration device are arranged in sequence in the flue gas flow direction in the tail flue of the boiler (1). The inlet of the plane (5) is connected, the output shaft of the turbine (5) is connected with the drive shaft of the generator (6), and the output end of the generator (6) is connected to the compressor (8) through the power switch (7). connect;

The tail flue is provided with a smoke outlet and a smoke inlet, wherein the smoke outlet is located between the high temperature superheater (2) and the low temperature superheater (3), and the outlet of the smoke outlet is connected to the outlet of the freon-flue gas heat exchanger (9). The hot side inlet is communicated, and the heat release side outlet of the freon-flue gas heat exchanger (9) is communicated with the flue gas inlet, wherein the flue gas inlet is located between the economizer (4) and the SCR denitration device;

The outlet of the compressor (8) is communicated with the inlet of the air compressor (11) through the heat absorption side of the freon-flue gas heat exchanger (9) and the heat release side of the condensing heat exchanger (10). The outlet of 11) is communicated with the heat-absorbing side inlet of the evaporative heat exchanger (13) through the throttle valve (12), and the heat-absorbing side outlet of the evaporative heat exchanger (13) is communicated with the inlet of the compressor (8);

The circulating cooling water outlet of the condenser is communicated with the heat release side inlet of the evaporative heat exchanger (13), and the heat absorption side outlet of the evaporative heat exchanger (13) is divided into two paths, one of which is connected with the output pipe, and the other It is communicated with the inlet of the mixing header (24), the outlet of the heat network return water storage tank (19) is communicated with the inlet of the mixing header (24), and the outlet of the mixing header (24) is communicated with the condensing heat exchanger ( 10) is communicated with the heat-absorbing side inlet, and the heat-absorbing side outlet of the condensing heat exchanger (10) is communicated with the inlet of the heat network water supply water storage tank (17).
The thermal power plant coupled high-efficiency compression heat pump energy storage peak regulation system according to claim 1, characterized in that, the outlet of the smoke outlet passes through the #1 electric gate valve (14) and the high temperature and high pressure fan (15) to exchange heat with freon-flue gas The inlets of the exothermic side of the device (9) are communicated with each other.
The thermal power plant coupled high-efficiency compression heat pump energy storage peak-shaving system according to claim 1, characterized in that, the outlet on the exothermic side of the freon-flue gas heat exchanger (9) passes through the #2 electric gate valve (16) and the flue gas The entrance is connected.
The thermal power plant coupled high-efficiency compression heat pump energy storage peak regulation system according to claim 1, wherein the air compressor (11) is a piston air compressor.
The thermal power plant coupled high-efficiency compression heat pump energy storage peak regulation system according to claim 1, characterized in that, the outlet of the heat absorption side of the evaporative heat exchanger (13) is divided into two paths after passing through the #1 electric regulating valve (21). , one of which is communicated with the output pipeline, and the other is communicated with the inlet of the mixing header (24) via the #2 electric regulating valve (22) and the circulating water pump (23).
The thermal power plant coupled high-efficiency compression heat pump energy storage and peak regulation system according to claim 1, further comprising a heat network return water circulation pump (20) and a heat network water supply circulation pump (18), a heat network return water circulation pump ( The outlet of 20) is communicated with the inlet of the heating network return water storage tank (19); the outlet of the heating network water supply storage tank (17) is communicated with the heating network water supply circulating pump (18).
The thermal power plant coupled high-efficiency compression heat pump energy storage peak-shaving system according to claim 1, characterized in that a condenser is circulated between the circulating cooling water outlet of the condenser and the heat release side inlet of the evaporative heat exchanger (13). The water pump (25) is connected.
A thermal power plant coupled high-efficiency compression heat pump energy storage peak regulation method, characterized in that, based on the thermal power plant coupled high-efficiency compression heat pump energy storage peak regulation system according to claim 1, comprising the following steps:

When the thermal power unit needs deep peak shaving, the power switch (7) is closed, the compressor (8) is energized, high-temperature flue gas is extracted through the exhaust port, and sent to the freon-flue gas heat exchanger (9) for heat release , the freon output by the compressor (8) enters into the freon-flue gas heat exchanger (9) for isobaric reheating, the exothermic flue gas enters the tail flue, and then enters the SCR denitration device for denitration treatment , in order to reduce the heat absorption of the low-temperature superheater (3) and the economizer (4), thereby reducing the evaporation and power generation of the boiler (1), to achieve peak regulation of the boiler (1), and at the same time increase the power plant through the operation of the compressor (8). Use electricity, reduce the electricity supplied to the outside world, and realize peak regulation of the boiler (1);

The high temperature and high pressure medium output from the freon-flue gas heat exchanger (9) enters the condensing heat exchanger (10) for heat release, and the return water of the heat network and the cooling water output from the heat release side of the evaporative heat exchanger (13) are mixed and collected. After mixing in the box (24), it enters the condensing heat exchanger (10) to absorb heat, and is then stored in the water supply water storage tank (17) of the heat network; In the compressor (11), the high pressure is used to push the piston, the high-pressure air is converted to store energy, and then the pressure is reduced by the throttle valve (12) and then enters the evaporative heat exchanger (13) for heat exchange with the circulating cooling water, so as to Absorb low-grade heat source in circulating cooling water;

When the demand for power generation and power supply of the thermal power unit increases, the power switch (7) is turned off, and the boiler (1) operates independently to generate electricity. Provide heat to reduce air extraction and increase power generation.