Disclosure of Invention
The invention aims to solve the problems that electric power resources cannot be directly stored and need to be matched with electric loads in the prior art, and the flexibility of a cogeneration unit is greatly limited, and further provides a solar thermoelectric coupling system based on the combination of heat storage and a compression heat pump and an operation method thereof. According to the invention, through organically combining a plurality of systems, the decoupling of heat supply and power supply is realized by fully exerting the combination advantages, the flexible operation of the photo-thermal-thermoelectric combined supply unit is realized, the consumption capability of a power grid on new energy electric power is adapted, and the solar photovoltaic combined supply system has remarkable social benefits and engineering application prospects.
In order to realize the purpose, the invention adopts the following technical scheme:
the first scheme is as follows: a solar thermoelectric coupling system based on combination of heat storage and a compression heat pump comprises a heat storage subsystem, a power island subsystem and a compression heat pump waste heat recovery subsystem;
the heat storage subsystem comprises a solar heat collector, a high-temperature heat accumulator, a high-temperature evaporator, a low-temperature evaporator and a low-temperature heat accumulator which are sequentially arranged on a heat storage circulating working loop, wherein the high-temperature evaporator provides required driving steam for the power island subsystem, and the low-temperature evaporator provides required driving steam for the compression heat pump waste heat recovery subsystem;
and the low-pressure heat exchanger of the compression type heat pump waste heat recovery subsystem is connected with the cold end circulating water of the power island system, and the high-pressure heat exchanger of the compression type heat pump waste heat recovery subsystem is connected with the heat user heat exchange station.
The working principle is as follows: two paths of steam generated by the heat storage subsystem respectively drive a steam turbine of the power island subsystem to do work and the compression heat pump waste heat recovery subsystem to realize heat supply, and the compression heat pump waste heat recovery subsystem supplies a low-temperature heat source to come from the circulating cold end of the power island system, so that the decoupling of power supply and heat supply is realized.
Further, the method comprises the following steps: the compression type heat pump waste heat recovery subsystem comprises a compressor, a high-pressure heat exchanger, a throttle valve I and a low-pressure heat exchanger which are sequentially arranged on a compression cycle working loop, the compressor is connected with a heat pump driving turbine, a low-temperature evaporator provides required driving steam for the heat pump driving turbine, and the high-pressure heat exchanger is connected with a heat user heat exchange station through a water supply loop.
Further: the power island system comprises a steam turbine, a condenser and a cooling tower, wherein a high-temperature evaporator provides required driving steam for the steam turbine, the steam turbine applies work to generate power, the exhaust end of the steam turbine is connected with the condenser, the condenser is respectively in circulating connection with the cooling tower and a low-pressure heat exchanger, a condensed liquid outlet of the condenser is connected with the high-temperature evaporator and the low-temperature evaporator through a heat pump circulating loop, and a heat pump driving turbine is connected with an inlet end of the condenser.
Further, the method comprises the following steps: the condensed fluid flow of the condenser is divided into two paths by a pipeline, wherein one path is a condenser outlet, a booster pump, a three-way control valve IV, a three-way control valve III, a throttle valve II, a three-way control valve II, a low-temperature evaporator, a heat pump driving turbine and a condenser inlet which are connected in sequence; the other path is a condenser outlet, a booster pump, a three-way control valve IV, a three-way control valve III, a three-way control valve I, a high-temperature evaporator, a steam turbine and a condenser inlet which are connected in sequence.
Further: and a three-way control valve V and a three-way control valve VI are arranged on the water supply loop, the three-way control valve V is connected with a three-way control valve III, and the three-way control valve VI is connected with a three-way control valve IV.
Further: the solar thermal collector is a tower type solar energy thermoelectric and photo-thermal energy storage system, a groove type solar energy thermoelectric and photo-thermal energy storage system or a disc type solar energy photo-thermal energy storage system.
Further: the working medium of the compression type heat pump waste heat recovery subsystem adopts an organic working medium, a carbon dioxide working medium or a mixed working medium of the two working media.
Scheme two is as follows: an operation method of a solar thermoelectric coupling system based on combination of heat storage and a compression heat pump is realized based on a first scheme. The method specifically comprises the following steps:
the operation process comprises three processes of solar heat storage, power island circulation and heat pump heating/refrigerating, and specifically comprises the following steps:
solar energy heat storage: a high-temperature evaporator and a low-temperature evaporator are arranged in the heat storage circulation working loop, wherein the high-temperature evaporator generates high-parameter steam which directly enters the power island subsystem to realize thermoelectric conversion; the low-temperature evaporator generates low-parameter steam which is used as a driving source for driving a heat pump driving turbine of the compression type heat pump waste heat recovery subsystem; the steam amount generated by the high-temperature evaporator and the low-temperature evaporator is adjusted through a three-way control valve I and a three-way control valve II, so that different load requirements are met;
circulating a power island: high-temperature high-pressure steam generated by the high-temperature evaporator enters a steam turbine to do work and generate power, the dead steam which does work is condensed into liquid in a condenser, high-pressure water pressurized by a booster pump passes through a three-way control valve III, a three-way control valve IV, a three-way control valve V and a three-way control valve VI to adjust the flow direction, whether preheating is needed or not is selected according to the load requirement of a heat user, and finally the high-pressure water is divided into two paths to respectively enter the high-temperature evaporator and the low-temperature evaporator to absorb heat and raise the temperature to design parameters, and the two paths respectively enter the steam turbine to expand to do work and generate power and a heat pump to drive a turbine to circularly drive a compressor, so that a cycle is completed;
heat pump heating/cooling cycle: under the working condition of summer, no heat supply demand exists, under the condition of high temperature in daytime, the three-way control valve II controls the heat pump circulation loop to be put into operation, the three-way control valve III and the three-way control valve IV control condensed water to enter the high-pressure heat exchanger, and the circulating water waste heat is recycled through heat pump circulation to be used for preheating the condensed water; the temperature at night is low, the temperature of the cold end of the power island meets the requirement of efficient operation of the unit, and the compression type heat pump waste heat recovery subsystem is stopped by adjusting the control of the three-way control valve II; under the working condition in winter, the compression type heat pump waste heat recovery subsystem directly supplies the waste heat recovered from the circulating water to a heat user heat exchange station to supply heat to users by adjusting the three-way control valve II, the three-way control valve III, the three-way control valve IV and the three-way control valve V; a heat supply loop: the heat pump working medium of the compression type heat pump waste heat recovery subsystem realizes the waste heat recovery of the cold end of the power island through the high-pressure heat exchanger and the low-pressure heat exchanger, and supplies heat for the heat supply circulating water, and then the heat supply circulating water supplies heat to users through a heat supply pipe network.
The invention achieves the following effects:
1. the invention comprehensively considers the characteristics of the power island circulation and the compression heat pump circulation of the photo-thermal unit, and adopts a solar heat storage system as a driving heat source to realize the purposes of power generation, heat supply and even refrigeration.
2. According to the invention, through organically combining a plurality of systems, the combined advantages are fully exerted to realize the decoupling of heat supply and power supply, the flexible operation of the photo-thermal-thermoelectric combined supply unit is realized, the consumption capacity of a power grid on new energy electric power is adapted, the thought is novel, the feasibility is high, and the social benefit and the engineering application prospect are obvious.
3. The invention realizes the decoupling operation of the power island system power generation and heat supply system by combining the heat pump system and the photo-thermal power station energy storage system, simultaneously recovers the waste heat of the cold end, realizes the cascade utilization of energy, reduces the heat emission on one hand, and meets the flexible supply of electricity and heat loads of users on the other hand.
4. On the premise of low cost, the solar-thermal power generation and cogeneration system realizes decoupling operation of power generation and heat supply, so that system energy is comprehensively and hierarchically utilized, and the operation flexibility of the solar-thermal power generation and cogeneration unit is improved.
Detailed Description
In order to make the technical solutions better understood by those skilled in the art, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only partial embodiments of the present application, but not all embodiments. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments in the present application without making any creative effort shall fall within the protection scope of the present application.
It should be noted that the terms "first," "second," and the like in the description and claims of this application and in the drawings described above are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It should be understood that the data so used may be interchanged under appropriate circumstances in order to facilitate the description of the embodiments of the application herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.
In the present application, the terms "upper", "lower", "inner", "middle", "outer", "front", "rear", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings. These terms are used primarily to better describe the present application and its embodiments, and are not used to limit the indicated devices, elements or components to a particular orientation or to be constructed and operated in a particular orientation.
Moreover, some of the above terms may be used to indicate other meanings besides the orientation or positional relationship, for example, the term "on" may also be used to indicate some kind of attachment or connection relationship in some cases. The specific meaning of these terms in this application will be understood by those of ordinary skill in the art as appropriate.
Furthermore, the terms "disposed," "connected," and "secured" are to be construed broadly. For example, "connected" may be a fixed connection, a detachable connection, or a unitary construction; can be a mechanical connection, or an electrical connection; may be directly connected, or indirectly connected through intervening media, or may be in internal communication between two devices, elements or components. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art as the case may be.
It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present application will be described in detail below with reference to the embodiments with reference to the attached drawings.
Preferred embodiments of the present invention are explained in detail below with reference to the accompanying drawings.
Example 1: as shown in fig. 1, the solar thermoelectric coupling system based on the combination of heat storage and compression heat pump in the embodiment includes a heat storage subsystem, a power island subsystem and a compression heat pump waste heat recovery subsystem; the heat storage subsystem comprises a solar heat collector 1, a high-temperature heat accumulator 2, a high-temperature evaporator 3, a low-temperature evaporator 4 and a low-temperature heat accumulator 5 which are sequentially arranged on a heat storage circulating working loop, the high-temperature evaporator 3 provides required driving steam for the power island subsystem, and the low-temperature evaporator 4 provides required driving steam for the compression type heat pump waste heat recovery subsystem; and a low-pressure heat exchanger 13 of the compression type heat pump waste heat recovery subsystem is connected with cold-end circulating water of the power island system, and a high-pressure heat exchanger 11 of the compression type heat pump waste heat recovery subsystem is connected with a heat user heat exchange station 14.
The compression type heat pump waste heat recovery subsystem comprises a compressor 10, a high-pressure heat exchanger 11, a throttle valve I12 and a low-pressure heat exchanger 13 which are sequentially arranged on a compression cycle working loop, the compressor 10 is connected with a heat pump driving turbine 9, a low-temperature evaporator 4 provides required driving steam for the heat pump driving turbine 9, and the high-pressure heat exchanger 11 is connected with a heat user heat exchange station 14 through a water supply loop. The power island subsystem comprises a steam turbine 6, a condenser 7 and a cooling tower 8, a high-temperature evaporator 3 provides required driving steam for the steam turbine 6, the steam turbine applies work to generate electricity, a steam exhaust end of the steam turbine 6 is connected with the condenser 7, the condenser 7 is respectively in circulating connection with the cooling tower 8 and a low-pressure heat exchanger 13, a condensed liquid outlet of the condenser 7 is connected with the high-temperature evaporator 3 and the low-temperature evaporator 4 through a heat pump circulating loop, and a heat pump driving turbine 9 is connected with an inlet end of the condenser 7. The condensed fluid flow of the condenser 7 is divided into two paths by a pipeline, wherein one path is an outlet of the condenser 7, a booster pump, a three-way control valve IV, a three-way control valve III, a throttle valve II, a three-way control valve II, a low-temperature evaporator 4, a heat pump driving turbine 9 and an inlet of the condenser 7 which are connected in sequence; the other path is a condenser 7 outlet, a booster pump, a three-way control valve IV, a three-way control valve III, a three-way control valve I, a high-temperature evaporator 3, a steam turbine 6 and a condenser 7 inlet which are connected in sequence. And a three-way control valve V and a three-way control valve VI are arranged on the water supply loop, the three-way control valve V is connected with a three-way control valve III, and the three-way control valve VI is connected with a three-way control valve IV.
The solar heat collector 1 is a tower type solar thermoelectric light-heat energy storage system; and the working medium of the compression type heat pump waste heat recovery subsystem is an organic working medium.
Embodiment 2, the difference with embodiment 1 is that the solar thermal collector 1 is a trough-type solar thermoelectric thermal energy storage system; the working medium of the compression type heat pump waste heat recovery subsystem adopts a carbon dioxide working medium.
Embodiment 3 is different from embodiment 1 in that the solar thermal collector 1 is a disc-type solar photo-thermal energy storage system, and the working medium of the compression-type heat pump waste heat recovery subsystem is a mixed working medium of an organic working medium and carbon dioxide.
The working principle of examples 1 to 3 is: two paths of steam generated by the heat storage subsystem respectively drive the power island steam turbine to do work and the heat pump unit to realize heat supply, and the heat pump unit supplies heat to the low-temperature heat source from the circulating cold end of the power island, so that the energy utilization efficiency is improved while the power supply and the heat supply are decoupled. The solar thermal electrolytic coupling system takes an energy storage subsystem of a photo-thermal power generation system as a key part of decoupling, power sources required by power island circulation and compression heat pump circulation are respectively generated to form a combined circulation system, wherein the power circulation and the heat pump circulation realize the switching adjustment of material flow through a plurality of regulating valves, and the organic combination among the subsystems is realized.
It is emphasized that the solar thermoelectric decoupling system has the following technical characteristics:
(1) When no heat supply load exists, the power island of the tower type solar power generation system circulates in the following working process: the feed water is heated to a given parameter and then enters a turbine to expand and do work, the exhaust gas waste heat of the feed water is condensed by circulating water, and the circulating water can be divided into two paths according to actual operating conditions and respectively enters a cooling tower to be condensed or a compression heat pump to realize condensation. Meanwhile, after being pressurized by the pump, the condensed water can enter the heat pump system again to absorb heat from a low-pressure side working medium to realize water supply preheating, and finally enters the heat storage system to absorb heat to complete a cycle.
(2) The power island circulation working process of the tower type solar power generation system when heat supply is needed is as follows: the pressurized feed water absorbs heat in the heat storage system, the temperature is raised to a given parameter, the feed water enters a turbine to expand and do work, and exhaust gas waste heat is transferred to a working medium at the low-pressure side of the heat pump through a heat exchanger to realize condensation. After condensation, water is pressurized by a pump and finally enters a heat storage system to absorb heat, and a cycle is completed.
(3) Compression heat pump waste heat recovery heating system, its work flow is: the working medium of the heat pump is evaporated at low pressure, the waste heat at the cold end of the power island is absorbed, and then the steam is compressed into high-temperature high-pressure fluid by the compressor. The heat exchange is carried out between the heat exchanger and the heat supply circulating water, then the heat exchange is carried out through cooling and throttling, the liquid phase fluid is changed into low-temperature low-pressure liquid phase fluid, the low-temperature low-pressure liquid phase fluid is evaporated again to absorb heat, the circulation is completed, and a driving source of the heat pump (refrigeration) circulation is provided from a heat storage system.
(4) And under the condition that the environmental temperature is low enough, the compression heat pump waste heat recovery heat supply system can be isolated and stopped through the regulating valve group configured on the power island system, and the power cycle adopts a pure Rankine cycle.
(5) The parameters and specific configuration of the power island system may vary with different heat source parameters and with different design requirements. Such as: arrangements such as reheat cycles can be employed to improve power island subsystem efficiency.
(6) According to the change of the consumption capacity of the power grid and the load of a power consumer, the power island can adjust the amount of generated steam according to the demand, so that the supply of power generation according to the demand is realized without influencing the change of heat supply.
(7) The working medium type and the operation parameter of the compression heat pump waste heat recovery heat supply system can be changed according to specific conditions. Such as: organic working media, carbon dioxide, mixed working media and the like can be adopted as the working media; the arrangement modes such as multi-stage circulation, regenerative circulation and the like can be adopted. The invention does not expand the working medium types, specific layouts and operation parameters of the heat pump system, and only selects one representative structure for discussion.
Example 4: an operation method of a solar thermoelectric coupling system based on combination of heat storage and a compression heat pump is realized based on embodiments 1, 2 or 3. The method comprises the following specific steps:
the operation process comprises three processes of solar heat storage, power island circulation and heat pump heating/refrigerating, and specifically comprises the following steps:
solar energy heat storage: the solar heat collector 1 is the key for realizing thermoelectric decoupling, a high-temperature evaporator 3 and a low-temperature evaporator 4 are arranged in a heat storage circulating working loop, wherein the high-temperature evaporator 3 generates high-parameter steam which directly enters a power island subsystem to realize thermoelectric conversion; the low-temperature evaporator 4 generates low-parameter steam which is used as a driving source for driving a heat pump driving turbine 9 of the compression type heat pump waste heat recovery subsystem; the steam amount generated by the high-temperature evaporator 3 and the low-temperature evaporator 4 is adjusted through a three-way control valve IA1 and a three-way control valve IIA2, so that different load requirements are met;
power island circulation: high-temperature high-pressure steam generated by the high-temperature evaporator 3 enters a steam turbine 6 to do work for power generation, the dead steam which does work is condensed into liquid in a condenser 7, high-pressure water pressurized by a booster pump passes through a three-way control valve IIIA3, a three-way control valve IVA4, a three-way control valve VA5 and a three-way control valve VIA6 to adjust the flow direction, whether preheating is needed or not is selected according to the load requirement of a heat user, and finally the high-pressure water is divided into two paths to respectively enter the high-temperature evaporator 3 and the low-temperature evaporator 4 to absorb heat and raise the temperature to design parameters, and then the two paths respectively enter the steam turbine 6 to do work for power generation and a heat pump driving turbine 9 to circularly drive a compressor 10, so that a cycle is completed;
heat pump heating/cooling cycle: under the working condition of summer, no heat supply requirement exists, under the condition of high temperature in daytime, the three-way control valve IIA2 controls the heat pump circulation loop to be put into operation, the three-way control valve IIIA3 and the three-way control valve IVA4 control the condensed water to enter the high-pressure heat exchanger 11, and the circulating water waste heat is recovered through heat pump circulation to be used for preheating the condensed water; the air temperature is low at night, the temperature of the cold end of the power island meets the requirement of high-efficiency operation of the unit, and the compression type heat pump waste heat recovery subsystem is stopped by adjusting the control of the three-way control valve IIA 2; under the working condition in winter, the compression type heat pump waste heat recovery subsystem directly supplies waste heat recovered from circulating water to a heat user heat exchange station 14 to supply heat to users by adjusting a three-way control valve IIA2, a three-way control valve IIIA3, a three-way control valve IVA4 and a three-way control valve VA 5; a heat supply loop: the heat pump working medium of the compression type heat pump waste heat recovery subsystem realizes the waste heat recovery of the cold end of the power island through the high-pressure heat exchanger 11 and the low-pressure heat exchanger 13, and supplies heat for the heat supply circulating water, and then the heat supply circulating water supplies heat for users through a heat supply pipe network. The heat supply circulating medium is generally water, but other media can be adopted according to actual needs.
It should be noted that the above-mentioned cycle is only an illustration of a simplest combined supply system in which a photothermal power generation system and a compression heat pump are combined to realize decoupling, and a system for practical engineering application will be more complicated, and in order to improve cycle efficiency, the above-mentioned power island cycle may also be replaced by a more complicated system such as primary reheating, secondary reheating, etc., and auxiliary equipment may also be added as needed. The present embodiment is equivalent to or modified from the embodiment as long as the combination of the cycle of the photo-thermal power generation system and the heat pump cycle is not changed.
The above examples are only used to illustrate the technical solution of the present invention, and not to limit the same; although the present invention has been described in detail with reference to the above embodiments, it should be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and these modifications or substitutions do not depart from the scope of the embodiments of the present invention in nature. In particular, the above implementation shows only four layers of bionic vein structure, and the heat storage device with five layers and more or similar vein-shaped stacked beds has the same principle as the above implementation and should be included in the protection scope of the present invention.
Furthermore, it should be understood that although the present description refers to embodiments, not every embodiment may contain only a single embodiment, and such description is for clarity only, and those skilled in the art should integrate the description, and the embodiments may be combined as appropriate to form other embodiments understood by those skilled in the art.