CN117489427B - Peak regulating system and method of cogeneration unit coupled with steam energy accumulator - Google Patents

Abstract

The invention discloses a peak shaving system and method of a cogeneration unit coupled with a steam energy accumulator, and relates to the field of steam energy storage and power generation. The peak regulation system of the cogeneration unit comprises a steam power cycle thermal power generation subsystem, a steam energy storage subsystem and an absorption heat pump subsystem, wherein the subsystems are connected through a pipeline and a valve; the heat supply capacity of the cogeneration unit is improved through the coupling of the absorption heat pump subsystem, so that the energy utilization rate of the system is improved; the steam energy storage subsystem is coupled, so that the unit can safely, stably and rapidly realize lifting load of the unit no matter in a cogeneration mode or a pure power generation mode, and has better thermal decoupling and deep peak regulation capacity, so that fluctuation of renewable energy power is effectively stabilized, flexible and stable operation of the unit is ensured, and the capacity of the power grid for absorbing renewable energy power is improved.

Description

Peak regulating system and method of cogeneration unit coupled with steam energy accumulator

Technical Field

The invention relates to the technical field of steam energy storage and power generation, in particular to a peak shaving system and a peak shaving method of a cogeneration unit coupled with a steam energy accumulator.

Background

The grid-connected capacity of the renewable energy generator set is increased, so that the consumption of fossil energy and the emission of greenhouse gases are effectively reduced, and meanwhile, the stable operation of a power grid is seriously influenced due to the periodicity and unpredictability of the renewable energy generator set. In order to stabilize the fluctuation of renewable power and improve the capacity of the power grid for absorbing renewable energy sources, the traditional thermal generator set must have more flexible deep peak regulation capacity. And for the cogeneration unit, the double test of fluctuation of renewable energy power and fluctuation of user thermal load is faced. However, the conventional cogeneration system generally has the current situation of weak thermal decoupling capability and insufficient flexible peak shaving capability. Therefore, how to realize the thermal decoupling of the unit, develop flexible heat supply transformation, and develop advanced heat supply technology is urgent.

Disclosure of Invention

Aiming at the problems in the background art, the invention provides a peak shaving system and a peak shaving method for a cogeneration unit coupled with a steam accumulator, which effectively improve the thermoelectric decoupling capacity and the flexible peak shaving performance of the unit by coupling the steam accumulator and an absorption heat pump in a traditional steam power cycle thermal power generation subsystem.

In order to achieve the above object, the present invention provides the following solutions:

the invention provides a peak shaving system of a cogeneration unit coupled with a steam energy accumulator, which comprises the following components: the system comprises a steam power cycle thermal power generation subsystem, a steam energy storage subsystem and an absorption heat pump subsystem;

The steam power cycle thermal power generation subsystem includes: a steam generator (101), a high-pressure cylinder (102), a medium-pressure cylinder (103), a low-pressure cylinder (104), a generator (105), a first high-pressure heater (106), a second high-pressure heater (107), a third high-pressure heater (108), a deaerator (109), a water supply pump (110), a first low-pressure heater (111), a second low-pressure heater (112), a third low-pressure heater (113), a fourth low-pressure heater (114), a fifth low-pressure heater (115), a condenser (116), a condensate pump (117), a water supply pump (110), A drain pump (118), a first circulation pump (119), a cooling tower (120), a first diverter valve (121), and a first collector valve (122); A main steam pipeline at the outlet of the steam generator (101) is connected with the inlet of the high-pressure cylinder (102); the first-stage steam extraction of the high-pressure cylinder (102) is connected with a steam side inlet of a first high-pressure heater (106); the first path of exhaust steam of the high-pressure cylinder (102) is connected with a steam side inlet of the second high-pressure heater (107); the second path of exhaust steam of the high-pressure cylinder (102) is connected with a reheater inlet of the steam generator (101); the reheater outlet of the steam generator (101) is connected with the inlet of the medium pressure cylinder (103); the first-stage steam extraction of the medium pressure cylinder (103) is connected with a steam side inlet of the third high pressure heater (108); The second-stage steam extraction of the medium pressure cylinder (103) is connected with a first-path steam side inlet of the deaerator (109); the outlet of the deaerator (109) is connected with the inlet of the water feed pump (110); an outlet of the water feed pump (110) is connected with a water side inlet of the third high-pressure heater (108); the water side outlet of the third high-pressure heater (108) is connected with the water side inlet of the second high-pressure heater (107); the water side outlet of the second high-pressure heater (107) is connected with the water side inlet of the first high-pressure heater (106); the water side outlet of the first high-pressure heater (106) is connected with the inlet of the steam generator (101); the first path of exhaust steam of the medium pressure cylinder (103) is connected with a steam side inlet of the first low pressure heater (111); the second way exhaust steam of the medium pressure cylinder (103) is connected with the inlet of the low pressure cylinder (104); the first-stage steam extraction of the low-pressure cylinder (104) is connected with a steam side inlet of the second low-pressure heater (112); the second-stage steam extraction of the low-pressure cylinder (104) is connected with a steam side inlet of the third low-pressure heater (113); the third-stage steam extraction of the low-pressure cylinder (104) is connected with a steam side inlet of the fourth low-pressure heater (114); the fourth stage extraction of the low pressure cylinder (104) is connected with the steam side inlet of the fifth low pressure heater (115); the exhaust steam of the low-pressure cylinder (104) is connected with the inlet of the condenser (116); an outlet of the condenser (116) is connected with an inlet of the condensate pump (117); an outlet of the condensate pump (117) is connected with a water side inlet of the fifth low-pressure heater (115); a cooling water outlet of the condenser (116) is connected with an inlet of the first shunt valve (121); the second path outlet of the first flow dividing valve (121) is connected with the inlet of the cooling tower (120); the outlet of the cooling tower (120) is connected with a first path inlet of the first collecting valve (122); An outlet of the first collecting valve (122) is connected with an inlet of the first circulating pump (119); an outlet of the first circulating pump (119) is connected with a cooling water inlet of the condenser (116); the generator (105) is coaxially connected with the high-pressure cylinder (102), the medium-pressure cylinder (103) and the low-pressure cylinder (104);

The steam energy storage subsystem includes: a vapor accumulator (201), a first valve (202), a second valve (203), a third valve (204), a second combining valve (205), a fourth valve (206), a fifth valve (207), a sixth valve (208), and a seventh valve (209); the third exhaust of the medium pressure cylinder (103) is respectively connected with the inlet of the first valve (202) and the inlet of the second valve (203); the outlet of the first valve (202) is connected with the steam side inlet of the steam accumulator (201); the outlet of the second valve (203) is connected with the first path inlet of the second collecting valve (205); the first path outlet of the steam accumulator (201) is respectively connected with the inlet of the sixth valve (208) and the inlet of the seventh valve (209); an outlet of the sixth valve (208) is connected with a steam side inlet of the second low-pressure heater (112); the outlet of the seventh valve (209) is connected with the steam side inlet of the third low-pressure heater (113); the second path outlet of the steam accumulator (201) is connected with the inlet of the third valve (204); the outlet of the third valve (204) is connected with the second path inlet of the second collecting valve (205); an outlet of the condensate pump (117) is connected with an inlet of the fourth valve (206); the outlet of the fourth valve (206) is connected with a water supply side inlet of the steam accumulator (201); a third outlet of the steam accumulator (201) is connected with an inlet of the fifth valve (207); -an outlet of the fifth valve (207) is open to the external environment to drain the water in the steam accumulator (201);

The absorption heat pump subsystem comprises: an evaporator (301), an eighth valve (302), a condenser (303), a ninth valve (304), a generator (305), a heat exchanger (306), a tenth valve (307), a second circulation pump (308), and an absorber (309); the outlet of the second collecting valve (205) is connected with the steam side inlet of the generator (305); the steam side outlet of the generator (305) is connected with the second steam side inlet of the deaerator (109); the hot flow inlet of the evaporator (301) is connected with the first path outlet of the first flow dividing valve (121); the hot stream outlet of the evaporator (301) is connected with the second path inlet of the first collecting valve (122); the heat supply network backwater sequentially enters the absorber (309) and the condenser (303) to generate heat supply network water which meets the heat supply network requirement; a refrigerant vapor outlet of the generator (305) is connected to an inlet of the ninth valve (304); the outlet of the ninth valve (304) is connected with the steam side inlet of the condenser (303); the liquid water outlet of the condenser (303) is connected with the inlet of the eighth valve (302); the outlet of the eighth valve (302) is connected with the cold fluid inlet of the evaporator (301); -the evaporator (301) cold fluid outlet is connected to the water side inlet of the absorber (309); the high-temperature lithium bromide concentrated solution outlet of the generator (305) is connected with the lithium bromide concentrated solution inlet of the heat exchanger (306); the outlet of the lithium bromide concentrated solution of the heat exchanger (306) is connected with the inlet of the tenth valve (307); the outlet of the tenth valve (307) is connected with the lithium bromide concentrated solution inlet of the absorber (309); the outlet of the lithium bromide dilute solution of the absorber (309) is connected with the inlet of the second circulating pump (308); the outlet of the second circulating pump (308) is connected with the lithium bromide dilute solution inlet of the heat exchanger (306); the outlet of the heat exchanger (306) for the lithium bromide dilute solution is connected with the inlet of the generator (305) for the lithium bromide dilute solution.

Optionally, the absorption heat pump subsystem is a single-effect absorption heat pump or a double-effect absorption heat pump.

Optionally, the steam power cycle thermal power generation subsystem is a coal-fired power generation subsystem, a biomass power generation subsystem, a garbage combustion power generation subsystem or a nuclear power generation subsystem.

Optionally, chilled water generated by an evaporator (301) of the absorption heat pump subsystem is introduced into a condenser (116) of the steam power cycle thermal power generation subsystem for condensing low pressure cylinder exhaust steam.

Optionally, the steam accumulator (201) supplements water from an outlet of the condensate pump (117).

On the other hand, the invention also provides a peak shaving method of the cogeneration unit for coupling the steam energy accumulator, which is applied to a peak shaving system of the cogeneration unit for coupling the steam energy accumulator; the peak regulation method of the cogeneration unit coupled with the steam accumulator comprises the following steps:

When the system operates in the cogeneration mode, according to the demand of heat load of a user, if the electric load demand of the unit is unchanged and the heat load demand is reduced, the steam quantity required by the absorption heat pump is reduced at the moment, and the redundant steam generated by the steam power cycle thermal power generation subsystem is extracted from a steam exhaust pipeline of the medium-pressure cylinder (103) and is introduced into unsaturated water of the steam accumulator (201); as the amount of introduced steam increases, unsaturated water in the steam accumulator (201) is converted into saturated water under the design pressure of the steam accumulator (201), so that the energy storage process is completed;

When the electric load is unchanged, the heat load is rapidly increased and exceeds the heat load output of the unit, a third valve (204) on the steam accumulator (201) is opened, saturated water in the steam accumulator (201) is flashed into steam and enters a generator (305) in the absorption heat pump subsystem through a second collecting valve (205) due to pressure change, and the absorption heat pump is driven to generate domestic hot water, so that the heat load requirement of a user is met.

Optionally, the storage capacity of the steam accumulator (201) is determined by the amount of unsaturated water that the condensate pump (117) introduces into the steam accumulator (201).

Optionally, the peak shaving method of the cogeneration unit coupled with the steam accumulator further comprises the following steps:

When the system operates in the cogeneration mode, according to the demand of the heat load of a user, if the heat load demand of a unit is unchanged and the electric load demand is reduced, on the premise of preferentially meeting the heat load of the user, the redundant steam generated by the steam power cycle thermal power generation subsystem is extracted from a steam exhaust pipeline of the medium pressure cylinder (103) and is introduced into the steam accumulator (201) for storage, so that the steam quantity entering the low pressure cylinder (104) is reduced, and the acting of the low pressure cylinder (104) is reduced;

When the thermal load demand is unchanged and the electric load demand is increased, the opening of the sixth valve (208) and the seventh valve (209) are adjusted to control the steam pressure released from the steam accumulator (201), so that the first-stage steam extraction and the second-stage steam extraction of the low-pressure cylinder (104) are reduced, the work load of steam in the low-pressure cylinder (104) is increased, the generated energy of the steam power cycle thermal power generation subsystem is improved, and the electric load demand of a user is further met.

Optionally, the peak shaving method of the cogeneration unit coupled with the steam accumulator further comprises the following steps:

When the system operates in a pure power generation mode, only the steam power cycle thermal power generation subsystem and the steam energy storage subsystem are required to be put into operation; if the external electric load demand is reduced, a first valve (202) is opened at the moment, the exhaust steam of the medium-pressure cylinder is introduced into a steam accumulator (201) for storage, and the steam inlet quantity of the low-pressure cylinder (104) is reduced, so that the load reduction of the unit is realized; when the external electric load is increased, the opening degree of the sixth valve (208) and the seventh valve (209) is adjusted, the steam pressure released by the steam accumulator (201) is controlled, and then the first-stage steam extraction amount and the second-stage steam extraction amount of the low-pressure cylinder (104) are reduced, so that the load lifting of the unit is realized.

According to the specific embodiment provided by the invention, the invention discloses the following technical effects:

The peak regulation system and the peak regulation method of the cogeneration unit coupled with the steam accumulator provided by the invention are characterized in that the peak regulation system of the cogeneration unit comprises a steam power cycle thermal power generation subsystem, a steam energy storage subsystem and an absorption heat pump subsystem, wherein the subsystems are connected through pipelines and valves; the heat supply capacity of the cogeneration unit is improved through the coupling of the absorption heat pump subsystem, so that the energy utilization rate of the system is improved; the steam energy storage subsystem is coupled, so that the unit can safely, stably and rapidly realize lifting load of the unit no matter in a cogeneration mode or a pure power generation mode, and has better thermal decoupling and deep peak regulation capacity, so that fluctuation of renewable energy power is effectively stabilized, flexible and stable operation of the unit is ensured, and the capacity of the power grid for absorbing renewable energy power is improved.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are needed in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic structural diagram of a peak shaving system of a cogeneration unit coupled with a steam accumulator according to the present invention.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

The invention aims to provide a peak regulation system and a peak regulation method of a cogeneration unit for coupling a steam accumulator, which aim at the current situations of weak thermal decoupling capacity and insufficient flexible peak regulation capacity of the traditional cogeneration system.

In order that the above-recited objects, features and advantages of the present invention will become more readily apparent, a more particular description of the invention will be rendered by reference to the appended drawings and appended detailed description.

As shown in fig. 1, the peak shaving system of the cogeneration unit coupled with the steam accumulator of the invention comprises: the system comprises a steam power cycle thermal power generation subsystem, a steam energy storage subsystem and an absorption heat pump subsystem, wherein the subsystems are connected through pipelines and valves.

Specifically, the steam power cycle thermal power generation subsystem includes: the steam generator (101), the high-pressure cylinder (102), the medium-pressure cylinder (103), the low-pressure cylinder (104), the generator (105), the first high-pressure heater (106), the second high-pressure heater (107), the third high-pressure heater (108), the deaerator (109), the feed pump (110), the first low-pressure heater (111), the second low-pressure heater (112), the third low-pressure heater (113), the fourth low-pressure heater (114), the fifth low-pressure heater (115), the condenser (116), the condensate pump (117), the drain pump (118), the first circulating pump (119), the cooling tower (120), the first diverter valve (121) and the first collecting valve (122). In practical applications, the steam generator (101) may be any steam generator such as a boiler. The steam power cycle thermal power generation subsystem can be a coal-fired power generation subsystem, a biomass power generation subsystem, a garbage combustion power generation subsystem or a nuclear power generation subsystem.

Referring to fig. 1, a main steam line of an outlet of the steam generator (101) is connected with an inlet of the high pressure cylinder (102); the first-stage steam extraction of the high-pressure cylinder (102) is connected with a steam side inlet of a first high-pressure heater (106); the first path of exhaust steam of the high-pressure cylinder (102) is connected with a steam side inlet of the second high-pressure heater (107); the second path of exhaust steam of the high-pressure cylinder (102) is connected with a reheater inlet of the steam generator (101); the reheater outlet of the steam generator (101) is connected with the inlet of the medium pressure cylinder (103); the first-stage steam extraction of the medium pressure cylinder (103) is connected with a steam side inlet of the third high pressure heater (108); the second-stage steam extraction of the medium pressure cylinder (103) is connected with a first-path steam side inlet of the deaerator (109); the outlet of the deaerator (109) is connected with the inlet of the water feed pump (110); an outlet of the water feed pump (110) is connected with a water side inlet of the third high-pressure heater (108); the water side outlet of the third high-pressure heater (108) is connected with the water side inlet of the second high-pressure heater (107); the water side outlet of the second high-pressure heater (107) is connected with the water side inlet of the first high-pressure heater (106); the water side outlet of the first high pressure heater (106) is connected with the inlet of the steam generator (101).

The first path of exhaust steam of the medium pressure cylinder (103) is connected with a steam side inlet of the first low pressure heater (111); the second way exhaust steam of the medium pressure cylinder (103) is connected with the inlet of the low pressure cylinder (104); the first-stage steam extraction of the low-pressure cylinder (104) is connected with a steam side inlet of the second low-pressure heater (112); the second-stage steam extraction of the low-pressure cylinder (104) is connected with a steam side inlet of the third low-pressure heater (113); the third-stage steam extraction of the low-pressure cylinder (104) is connected with a steam side inlet of the fourth low-pressure heater (114); the fourth stage extraction of the low pressure cylinder (104) is connected with the steam side inlet of the fifth low pressure heater (115); the exhaust steam of the low-pressure cylinder (104) is connected with the inlet of the condenser (116); an outlet of the condenser (116) is connected with an inlet of the condensate pump (117); an outlet of the condensate pump (117) is connected with a water side inlet of the fifth low-pressure heater (115); a cooling water outlet of the condenser (116) is connected with an inlet of the first shunt valve (121); the second path outlet of the first flow dividing valve (121) is connected with the inlet of the cooling tower (120); the outlet of the cooling tower (120) is connected with a first path inlet of the first collecting valve (122); an outlet of the first collecting valve (122) is connected with an inlet of the first circulating pump (119); an outlet of the first circulating pump (119) is connected with a cooling water inlet of the condenser (116); the generator (105) is coaxially connected with the high-pressure cylinder (102), the medium-pressure cylinder (103) and the low-pressure cylinder (104).

The water supply pump (110) boosts the water supply at the outlet of the deaerator (109) and then leads the boosted water supply to the water side inlet of the third high-pressure heater (108). The steam generator (101) is used for heating the steam generator water supply of the water side outlet of the first high-pressure heater (106), and generated main steam enters the high-pressure cylinder (102) through a main steam pipeline of the outlet of the steam generator (101). On the other hand, reheat steam at a reheater outlet of the steam generator (101) is introduced into an inlet of the medium pressure cylinder (103). The water supply of the steam generator (101) (cooling water from the cooling tower (120) and the evaporator (301)) enters a water supply pipeline after being boosted by the condensate pump (117), and sequentially passes through the first high-pressure heater (106), the second high-pressure heater (107), the third high-pressure heater (108), the deaerator (109), the first low-pressure heater (111), the second low-pressure heater (112), the third low-pressure heater (113), the fourth low-pressure heater (114) and the fifth low-pressure heater (115), and is heated by the steam in the high-pressure heater and the low-pressure heater and meets the requirement of the inlet water supply parameter of the steam generator (101). Steam introduced into steam side inlets of the first high-pressure heater (106), the second high-pressure heater (107) and the third high-pressure heater (108) automatically flows step by step after water supply of the steam generator is heated, and finally flows into the deaerator (109). Steam introduced into steam side inlets of the first low-pressure heater (111) and the second low-pressure heater (112) automatically flows step by step after water supply of the steam generator is heated, and finally is collected into the third low-pressure heater (113). The drain water of the third low-pressure heater (113) is boosted by the drain pump (118) and then enters a water supply pipeline connecting the second low-pressure heater (112) and the third low-pressure pressurizer (113). The drain water of the fourth low-pressure heater (114) and the fifth low-pressure heater (115) automatically flow into the condenser (116) step by step. The first diverter valve (121) controls the flow of cooling water from the condenser (116) into the cooling tower (120) and evaporator (301). The first collecting valve (122) collects cooling water from the cooling tower (120) and the evaporator (301) and introduces the cooling water into the condenser (116). The cooling tower (120) and the evaporator (301) are used for cooling the cooling water branched by the first split valve (121). The high-pressure cylinder (102) and the medium-pressure cylinder (103) are coaxially connected with the low-pressure cylinder (104) and the generator (105) and drive the generator (105) to work so as to generate electric power.

Specifically, the steam energy storage subsystem includes: a vapor accumulator (201), a first valve (202), a second valve (203), a third valve (204), a second combining valve (205), a fourth valve (206), a fifth valve (207), a sixth valve (208), and a seventh valve (209).

Referring to fig. 1, a third exhaust of the medium pressure cylinder (103) is respectively connected with an inlet of the first valve (202) and an inlet of the second valve (203); the outlet of the first valve (202) is connected with the steam side inlet of the steam accumulator (201); the outlet of the second valve (203) is connected with the first path inlet of the second collecting valve (205); the first path outlet of the steam accumulator (201) is respectively connected with the inlet of the sixth valve (208) and the inlet of the seventh valve (209); an outlet of the sixth valve (208) is connected with a steam side inlet of the second low-pressure heater (112); the outlet of the seventh valve (209) is connected with the steam side inlet of the third low-pressure heater (113); the second path outlet of the steam accumulator (201) is connected with the inlet of the third valve (204); the outlet of the third valve (204) is connected with the second path inlet of the second collecting valve (205); an outlet of the condensate pump (117) is connected with an inlet of the fourth valve (206); the outlet of the fourth valve (206) is connected with a water supply side inlet of the steam accumulator (201); a third outlet of the steam accumulator (201) is connected with an inlet of the fifth valve (207); the outlet of the fifth valve (207) is open to the external environment to drain the water in the steam accumulator (201).

The steam accumulator (201) supplements water from an outlet of the condensate pump (117). The storage and release of steam in the steam energy storage subsystem is completed by controlling the valve opening or opening states of the first valve (202), the second valve (203), the third valve (204), the fourth valve (206), the fifth valve (207), the sixth valve (208) and the seventh valve (209). The water in the steam accumulator (201) can be discharged through the fifth valve (207).

Specifically, the absorption heat pump subsystem includes: an evaporator (301), an eighth valve (302), a condenser (303), a ninth valve (304), a generator (305), a heat exchanger (306), a tenth valve (307), a second circulation pump (308), and an absorber (309).

Referring to fig. 1, the outlet of the second collecting valve (205) is connected with the steam side inlet of the generator (305); the steam side outlet of the generator (305) is connected with the second steam side inlet of the deaerator (109); the hot flow inlet of the evaporator (301) is connected with the first path outlet of the first flow dividing valve (121); the hot stream outlet of the evaporator (301) is connected to the second inlet of the first collecting valve (122). The heat supply network backwater sequentially enters the absorber (309) and the condenser (303) to generate heat supply network water meeting the heat supply network requirement.

A refrigerant vapor outlet of the generator (305) is connected to an inlet of the ninth valve (304); the outlet of the ninth valve (304) is connected with the steam side inlet of the condenser (303); the liquid water outlet of the condenser (303) is connected with the inlet of the eighth valve (302); the outlet of the eighth valve (302) is connected with the cold fluid inlet of the evaporator (301); -the evaporator (301) cold fluid outlet is connected to the water side inlet of the absorber (309); the high-temperature lithium bromide concentrated solution outlet of the generator (305) is connected with the lithium bromide concentrated solution inlet of the heat exchanger (306); the outlet of the lithium bromide concentrated solution of the heat exchanger (306) is connected with the inlet of the tenth valve (307); the outlet of the tenth valve (307) is connected with the lithium bromide concentrated solution inlet of the absorber (309); the outlet of the lithium bromide dilute solution of the absorber (309) is connected with the inlet of the second circulating pump (308); the outlet of the second circulating pump (308) is connected with the lithium bromide dilute solution inlet of the heat exchanger (306); the outlet of the heat exchanger (306) for the lithium bromide dilute solution is connected with the inlet of the generator (305) for the lithium bromide dilute solution.

In the absorption heat pump subsystem, heat supply network backwater sequentially enters the absorber (309) and the condenser (303) to absorb heat to generate heat supply network water meeting the heat supply network requirement. The lithium bromide solution in the generator (305) is heated by steam from the outlet of the second collecting valve (205) to generate refrigerant steam, and the generated refrigerant steam enters the condenser (303) through the ninth valve (304), exchanges heat with heat network backwater for the second time and is condensed into liquid water. The liquid water outlet in the condenser (303) is connected with the inlet of the eighth valve (302); the outlet of the eighth valve (302) is connected with the cold fluid inlet of the evaporator (301); the evaporator (301) cold fluid outlet is connected to the water side inlet of the absorber (309). The high-temperature lithium bromide concentrated solution outlet of the generator (305) is connected with the lithium bromide concentrated solution inlet of the heat exchanger (306); the outlet of the lithium bromide concentrated solution of the heat exchanger (306) is connected with the inlet of the tenth valve (307); the outlet of the tenth valve (307) is connected with the lithium bromide concentrated solution inlet of the absorber (309); the outlet of the lithium bromide dilute solution of the absorber (309) is connected with the inlet of the second circulating pump (308); the outlet of the second circulating pump (308) is connected with the inlet of the lithium bromide dilute solution of the heat exchanger (306). The outlet of the lithium bromide dilute solution of the heat exchanger (306) is connected with the inlet of the lithium bromide dilute solution of the generator (305), and the low-temperature lithium bromide dilute solution from the outlet of the second circulating pump (308) is heated. The hot flow inlet of the evaporator (301) is connected with the first path outlet of the first flow dividing valve (121); the hot stream outlet of the evaporator (301) is connected to the second inlet of the first collecting valve (122).

In practical applications, the absorption heat pump subsystem may be a single-effect absorption heat pump or a double-effect absorption heat pump. Chilled water generated by an evaporator (301) of the absorption heat pump subsystem is introduced into a condenser (116) of the steam power cycle thermal power generation subsystem for condensing low-pressure cylinder exhaust steam.

The system comprises a steam power cycle thermal power generation subsystem, a steam energy storage subsystem and an absorption heat pump subsystem. If the system operates in the cogeneration mode, when the external electrical load demand is unchanged and the thermal load demand is reduced, part of steam in the steam turbine can be stored in the steam accumulator (201), so that the steam for driving the absorption heat pump is reduced; when the heat load demand increases, the stored steam can be released to be supplied to the absorption heat pump, so that the heat supply quantity of the heat pump is increased. When the heat load demand of the unit is unchanged and the electric load demand is reduced, and the electric power output of the thermal power generation subsystem of the steam power cycle is required to be rapidly reduced, the steam in the steam turbine can be stored into the steam accumulator (201), so that the steam quantity participating in the work in the steam turbine is reduced; when the electric load demand increases, the steam released in the steam accumulator (201) is introduced into the low-pressure heater to extrude the steam extracted from the low-pressure cylinder (104), so that the steam quantity of the unit participating in power generation is increased, and the quick load lifting of the unit is realized. If the system operates in a pure power generation mode, the absorption heat pump subsystem is not put into use, and when the external electric load demand changes, the quick load lifting of the unit is realized through energy storage and energy release of the steam accumulator (201). The steam energy storage subsystem and the absorption heat pump subsystem are coupled, so that the steam power cycle thermal power generation subsystem can safely, stably and rapidly realize lifting load of the unit no matter in a cogeneration mode or a pure power generation mode, thermoelectric decoupling and flexible peak regulation performances of the unit are improved, fluctuation of renewable energy power is effectively stabilized, and the capacity of the power grid for absorbing renewable energy is improved.

Based on the peak regulation system of the cogeneration unit of the coupling steam energy accumulator, the invention also provides a peak regulation method of the cogeneration unit of the coupling steam energy accumulator. Referring to fig. 1, the flexible peak shaving method of the cogeneration unit according to the present invention is described as follows.

When the system is operated in the cogeneration mode, the unit can have the following two operation adjustment modes according to the requirements of the heat load of a user: firstly, the electric load demand is unchanged, the thermal load demand is reduced, at the moment, the steam quantity required by the absorption heat pump is reduced, redundant steam generated by the steam power cycle thermal power generation subsystem is extracted from a steam exhaust pipeline of the medium pressure cylinder (103) and is introduced into unsaturated water of the steam accumulator (201), and along with the increase of the introduced steam quantity, the unsaturated water is converted into saturated water under the design pressure of the steam accumulator (201), so that the energy storage process is completed. The storage amount of the steam accumulator (201) is determined by the unsaturated water amount of the condensate pump (117) which is introduced into the steam accumulator (201); when the electric load is unchanged and the heat load is increased sharply and exceeds the heat load output of the unit, a third valve (204) on the steam accumulator (201) can be opened, saturated water in the steam accumulator can flash to become steam due to pressure change and enter a generator (305) in the absorption heat pump subsystem through a second collecting valve (205), and the absorption heat pump is driven to generate domestic hot water so as to meet the heat load requirement of a user; when the heat load demand is unchanged and the electric load demand is reduced, on the premise of preferentially meeting the heat load of a user, redundant steam generated by the steam power cycle thermal power generation subsystem is also extracted from a steam exhaust pipeline of the medium pressure cylinder (103) and is introduced into the steam accumulator (201) for storage, so that the steam quantity entering the low pressure cylinder (104) is reduced, and the acting of the low pressure cylinder (104) is reduced; when the thermal load demand is unchanged and the electrical load demand is increased, the opening of the sixth valve (208) and the seventh valve (209) are regulated, the steam pressure released from the steam accumulator (201) is controlled, the first-stage steam extraction and the second-stage steam extraction of the low-pressure cylinder (104) are further reduced, the acting amount of steam in the low-pressure cylinder is increased, the generating capacity of the steam power cycle thermal power generation subsystem is improved, and the electrical load demand of a user is further met.

When the system operates in a pure power generation mode, the system only needs to put the steam power cycle thermal power generation subsystem and the steam energy storage subsystem into operation, and the system has the following two operation regulation modes: firstly, the external electric load demand is reduced, the quick load reduction of the unit is required, at the moment, a first valve (202) is opened, the exhaust steam of the medium-pressure cylinder is introduced into a steam accumulator (201) for storage, and the steam inlet quantity of the low-pressure cylinder (104) is reduced, so that the quick load reduction of the unit is realized; and (II) when the external electric load is increased, the unit is required to rapidly lift, at the moment, the opening degree of the sixth valve (208) and the seventh valve (209) can be adjusted, the steam pressure released by the steam accumulator (201) is controlled, and the first-stage steam extraction amount and the second-stage steam extraction amount of the low-pressure cylinder (104) are further reduced, so that the rapid lifting load of the unit is realized.

Therefore, in the flexible peak shaving system of the cogeneration unit coupled with the steam energy accumulator, the coupled steam energy accumulator and the absorption heat pump can effectively improve the thermoelectric decoupling capacity and the flexible peak shaving performance of the thermal power unit under the cogeneration operation mode of the thermal power unit. When the unit operates in a pure power generation mode, the unit still has higher flexible peak shaving performance due to the coupling of the steam accumulator.

In the present specification, each embodiment is described in a progressive manner, and each embodiment is mainly described in a different point from other embodiments, and identical and similar parts between the embodiments are all enough to refer to each other.

The principles and embodiments of the present invention have been described herein with reference to specific examples, the description of which is intended only to assist in understanding the methods of the present invention and the core ideas thereof; also, it is within the scope of the present invention to be modified by those of ordinary skill in the art in light of the present teachings. In view of the foregoing, this description should not be construed as limiting the invention.

Claims (9)

1. A cogeneration unit peak shaving system coupled to a steam accumulator, comprising: the system comprises a steam power cycle thermal power generation subsystem, a steam energy storage subsystem and an absorption heat pump subsystem;

The steam power cycle thermal power generation subsystem includes: a steam generator (101), a high-pressure cylinder (102), a medium-pressure cylinder (103), a low-pressure cylinder (104), a generator (105), a first high-pressure heater (106), a second high-pressure heater (107), a third high-pressure heater (108), a deaerator (109), a water supply pump (110), a first low-pressure heater (111), a second low-pressure heater (112), a third low-pressure heater (113), a fourth low-pressure heater (114), a fifth low-pressure heater (115), a condenser (116), a condensate pump (117), a water supply pump (110), A drain pump (118), a first circulation pump (119), a cooling tower (120), a first diverter valve (121), and a first collector valve (122); A main steam pipeline at the outlet of the steam generator (101) is connected with the inlet of the high-pressure cylinder (102); the first-stage steam extraction of the high-pressure cylinder (102) is connected with a steam side inlet of a first high-pressure heater (106); the first path of exhaust steam of the high-pressure cylinder (102) is connected with a steam side inlet of the second high-pressure heater (107); the second path of exhaust steam of the high-pressure cylinder (102) is connected with a reheater inlet of the steam generator (101); the reheater outlet of the steam generator (101) is connected with the inlet of the medium pressure cylinder (103); the first-stage steam extraction of the medium pressure cylinder (103) is connected with a steam side inlet of the third high pressure heater (108); The second-stage steam extraction of the medium pressure cylinder (103) is connected with a first-path steam side inlet of the deaerator (109); the outlet of the deaerator (109) is connected with the inlet of the water feed pump (110); an outlet of the water feed pump (110) is connected with a water side inlet of the third high-pressure heater (108); the water side outlet of the third high-pressure heater (108) is connected with the water side inlet of the second high-pressure heater (107); the water side outlet of the second high-pressure heater (107) is connected with the water side inlet of the first high-pressure heater (106); the water side outlet of the first high-pressure heater (106) is connected with the inlet of the steam generator (101); the first path of exhaust steam of the medium pressure cylinder (103) is connected with a steam side inlet of the first low pressure heater (111); the second way exhaust steam of the medium pressure cylinder (103) is connected with the inlet of the low pressure cylinder (104); the first-stage steam extraction of the low-pressure cylinder (104) is connected with a steam side inlet of the second low-pressure heater (112); the second-stage steam extraction of the low-pressure cylinder (104) is connected with a steam side inlet of the third low-pressure heater (113); the third-stage steam extraction of the low-pressure cylinder (104) is connected with a steam side inlet of the fourth low-pressure heater (114); the fourth stage extraction of the low pressure cylinder (104) is connected with the steam side inlet of the fifth low pressure heater (115); the exhaust steam of the low-pressure cylinder (104) is connected with the inlet of the condenser (116); an outlet of the condenser (116) is connected with an inlet of the condensate pump (117); an outlet of the condensate pump (117) is connected with a water side inlet of the fifth low-pressure heater (115); a cooling water outlet of the condenser (116) is connected with an inlet of the first shunt valve (121); the second path outlet of the first flow dividing valve (121) is connected with the inlet of the cooling tower (120); the outlet of the cooling tower (120) is connected with a first path inlet of the first collecting valve (122); An outlet of the first collecting valve (122) is connected with an inlet of the first circulating pump (119); an outlet of the first circulating pump (119) is connected with a cooling water inlet of the condenser (116); the generator (105) is coaxially connected with the high-pressure cylinder (102), the medium-pressure cylinder (103) and the low-pressure cylinder (104);

The steam energy storage subsystem includes: a vapor accumulator (201), a first valve (202), a second valve (203), a third valve (204), a second combining valve (205), a fourth valve (206), a fifth valve (207), a sixth valve (208), and a seventh valve (209); the third exhaust of the medium pressure cylinder (103) is respectively connected with the inlet of the first valve (202) and the inlet of the second valve (203); the outlet of the first valve (202) is connected with the steam side inlet of the steam accumulator (201); the outlet of the second valve (203) is connected with the first path inlet of the second collecting valve (205); the first path outlet of the steam accumulator (201) is respectively connected with the inlet of the sixth valve (208) and the inlet of the seventh valve (209); an outlet of the sixth valve (208) is connected with a steam side inlet of the second low-pressure heater (112); the outlet of the seventh valve (209) is connected with the steam side inlet of the third low-pressure heater (113); the second path outlet of the steam accumulator (201) is connected with the inlet of the third valve (204); the outlet of the third valve (204) is connected with the second path inlet of the second collecting valve (205); an outlet of the condensate pump (117) is connected with an inlet of the fourth valve (206); the outlet of the fourth valve (206) is connected with a water supply side inlet of the steam accumulator (201); a third outlet of the steam accumulator (201) is connected with an inlet of the fifth valve (207); -an outlet of the fifth valve (207) is open to the external environment to drain the water in the steam accumulator (201);

The absorption heat pump subsystem comprises: an evaporator (301), an eighth valve (302), a condenser (303), a ninth valve (304), a generator (305), a heat exchanger (306), a tenth valve (307), a second circulation pump (308), and an absorber (309); the outlet of the second collecting valve (205) is connected with the steam side inlet of the generator (305); the steam side outlet of the generator (305) is connected with the second steam side inlet of the deaerator (109); the hot flow inlet of the evaporator (301) is connected with the first path outlet of the first flow dividing valve (121); the hot stream outlet of the evaporator (301) is connected with the second path inlet of the first collecting valve (122); the heat supply network backwater sequentially enters the absorber (309) and the condenser (303) to generate heat supply network water which meets the heat supply network requirement; a refrigerant vapor outlet of the generator (305) is connected to an inlet of the ninth valve (304); the outlet of the ninth valve (304) is connected with the steam side inlet of the condenser (303); the liquid water outlet of the condenser (303) is connected with the inlet of the eighth valve (302); the outlet of the eighth valve (302) is connected with the cold fluid inlet of the evaporator (301); -the evaporator (301) cold fluid outlet is connected to the water side inlet of the absorber (309); the high-temperature lithium bromide concentrated solution outlet of the generator (305) is connected with the lithium bromide concentrated solution inlet of the heat exchanger (306); the outlet of the lithium bromide concentrated solution of the heat exchanger (306) is connected with the inlet of the tenth valve (307); the outlet of the tenth valve (307) is connected with the lithium bromide concentrated solution inlet of the absorber (309); the outlet of the lithium bromide dilute solution of the absorber (309) is connected with the inlet of the second circulating pump (308); the outlet of the second circulating pump (308) is connected with the lithium bromide dilute solution inlet of the heat exchanger (306); the outlet of the heat exchanger (306) for the lithium bromide dilute solution is connected with the inlet of the generator (305) for the lithium bromide dilute solution.

2. The cogeneration unit peak shaver system coupled with a steam accumulator of claim 1, wherein the absorption heat pump subsystem is a single-effect absorption heat pump or a double-effect absorption heat pump.

3. The cogeneration unit peak shaver system coupled with the steam accumulator according to claim 1, wherein the steam power cycle thermal power generation subsystem is a coal-fired power generation subsystem, a biomass power generation subsystem, a garbage combustion power generation subsystem or a nuclear power generation subsystem.

4. The cogeneration unit peak shaver system coupled with a steam accumulator according to claim 1, wherein chilled water generated by an evaporator (301) of the absorption heat pump subsystem is introduced into a condenser (116) of the steam power cycle thermal power generation subsystem for condensing low pressure cylinder exhaust steam.

5. The cogeneration unit peak shaver system coupled to a steam accumulator according to claim 1, wherein the steam accumulator (201) supplements water from an outlet of the condensate pump (117).

6. A peak shaving method of a cogeneration unit coupled with a steam accumulator, which is characterized by being applied to the peak shaving system of the cogeneration unit coupled with the steam accumulator according to any one of claims 1 to 5; the peak regulation method of the cogeneration unit coupled with the steam accumulator comprises the following steps:

When the system operates in the cogeneration mode, according to the demand of heat load of a user, if the electric load demand of the unit is unchanged and the heat load demand is reduced, the steam quantity required by the absorption heat pump is reduced at the moment, and the redundant steam generated by the steam power cycle thermal power generation subsystem is extracted from a steam exhaust pipeline of the medium-pressure cylinder (103) and is introduced into unsaturated water of the steam accumulator (201); as the amount of introduced steam increases, unsaturated water in the steam accumulator (201) is converted into saturated water under the design pressure of the steam accumulator (201), so that the energy storage process is completed;

When the electric load is unchanged, the heat load is rapidly increased and exceeds the heat load output of the unit, a third valve (204) on the steam accumulator (201) is opened, saturated water in the steam accumulator (201) is flashed into steam and enters a generator (305) in the absorption heat pump subsystem through a second collecting valve (205) due to pressure change, and the absorption heat pump is driven to generate domestic hot water, so that the heat load requirement of a user is met.

7. The peak shaver method for a cogeneration unit coupled to a steam accumulator according to claim 6, wherein the amount of stored steam of the steam accumulator (201) is determined by the amount of unsaturated water fed to the steam accumulator (201) by the condensate pump (117).

8. The cogeneration unit peaking method coupled with a steam accumulator of claim 6, further comprising:

When the system operates in the cogeneration mode, according to the demand of the heat load of a user, if the heat load demand of a unit is unchanged and the electric load demand is reduced, on the premise of preferentially meeting the heat load of the user, the redundant steam generated by the steam power cycle thermal power generation subsystem is extracted from a steam exhaust pipeline of the medium pressure cylinder (103) and is introduced into the steam accumulator (201) for storage, so that the steam quantity entering the low pressure cylinder (104) is reduced, and the acting of the low pressure cylinder (104) is reduced;

When the thermal load demand is unchanged and the electric load demand is increased, the opening of the sixth valve (208) and the seventh valve (209) are adjusted to control the steam pressure released from the steam accumulator (201), so that the first-stage steam extraction and the second-stage steam extraction of the low-pressure cylinder (104) are reduced, the work load of steam in the low-pressure cylinder (104) is increased, the generated energy of the steam power cycle thermal power generation subsystem is improved, and the electric load demand of a user is further met.

9. The cogeneration unit peaking method coupled with a steam accumulator of claim 6, further comprising:

When the system operates in a pure power generation mode, only the steam power cycle thermal power generation subsystem and the steam energy storage subsystem are required to be put into operation; if the external electric load demand is reduced, a first valve (202) is opened at the moment, the exhaust steam of the medium-pressure cylinder is introduced into a steam accumulator (201) for storage, and the steam inlet quantity of the low-pressure cylinder (104) is reduced, so that the load reduction of the unit is realized; when the external electric load is increased, the opening degree of the sixth valve (208) and the seventh valve (209) is adjusted, the steam pressure released by the steam accumulator (201) is controlled, and then the first-stage steam extraction amount and the second-stage steam extraction amount of the low-pressure cylinder (104) are reduced, so that the load lifting of the unit is realized.