Disclosure of Invention
Based on the above, the present invention provides a heat pump energy storage system, which can convert surplus electric power into heat energy for storage, and improve the efficiency of electric heat energy storage.
In order to achieve the purpose, the invention adopts the following technical scheme:
a heat pump energy storage system is used for converting surplus electric power of a power generation device into heat energy for storage, and comprises a motor, a compressor, a first heat exchanger, a second heat exchanger, a turbine assembly, a third heat exchanger, a first heat storage assembly, a second heat storage assembly and a third heat storage assembly;
the surplus power is input into the motor, and the motor is in driving connection with the compressor to drive the compressor to work;
the compressor, the high-temperature side of the first heat exchanger, the high-temperature side of the second heat exchanger, the turbine assembly and the low-temperature side of the third heat exchanger are sequentially communicated in series through heat exchange working medium pipelines to form a heat exchange loop;
the first heat storage assembly is communicated with the low-temperature side of the first heat exchanger through a first heat storage medium pipeline to form a first energy storage loop, and a first heat storage medium flows through the first heat storage medium pipeline;
the second heat storage assembly is communicated with the low-temperature side of the second heat exchanger through a second heat storage medium pipeline to form a second energy storage loop, and a second heat storage medium flows through the second heat storage medium pipeline;
the third heat storage assembly is communicated with the high-temperature side of the third heat exchanger through a third heat storage medium pipeline to form a third heat storage loop, and a third heat storage medium flows through the third heat storage medium pipeline.
As a preferable scheme of the heat pump energy storage system, the first heat storage assembly includes:
the first cold tank, the low temperature side of first heat exchanger and first hot tank pass through first heat-retaining medium pipeline establishes ties in proper order and communicates formation first heat-retaining return circuit.
As a preferable scheme of the heat pump energy storage system, the second heat storage assembly includes:
the second heat storage medium pipeline is sequentially communicated in series to form the second heat storage loop.
As a preferable scheme of the heat pump energy storage system, the system further comprises:
and the thermal power generation device is communicated with the first heat storage medium pipeline, is positioned between the inlet of the first cold tank and the outlet of the first hot tank, and is also communicated between the inlet of the second cold tank and the outlet of the second hot tank through the second heat storage medium pipeline.
As a preferable scheme of the heat pump energy storage system, the third heat storage assembly includes:
the high-temperature sides of the third cold tank, the solar heat collection device, the third hot tank and the third heat exchanger are sequentially communicated in series through a third heat storage medium pipeline to form a third heat storage loop.
As a preferable scheme of the heat pump energy storage system, the turbine assembly comprises:
the high-pressure turbine is communicated between the high-temperature side of the second heat exchanger and the low-temperature high-pressure side of the third heat exchanger through the heat exchange working medium pipeline, and the low-pressure turbine is communicated between the low-temperature high-pressure side and the low-temperature low-pressure side of the third heat exchanger through the heat exchange working medium pipeline.
As a preferred embodiment of the heat pump energy storage system, the high pressure turbine and the low pressure turbine are respectively in transmission connection with the compressor.
As a preferable scheme of the heat pump energy storage system, the first heat storage medium is molten salt.
As a preferred scheme of the heat pump energy storage system, the second heat storage medium is heat conduction oil.
As a preferable scheme of the heat pump energy storage system, the third heat storage medium is normal pressure water.
The invention has the beneficial effects that:
the invention provides a heat pump energy storage system which is used for converting surplus electric power of a power generation device into heat energy for storage, and comprises a motor, an electricity storage device, a compressor, a first heat exchanger, a second heat exchanger, a turbine assembly, a third heat exchanger, a first heat storage assembly, a second heat storage assembly and a third heat storage assembly, wherein the surplus electric power is input into the motor, the motor drives the compressor to work, a heat exchange working medium is pressurized and heated by the compressor, then the heat exchange working medium sequentially enters the high-temperature side of the first heat exchanger and the high-temperature side of the second heat exchanger, and heat is respectively transferred to the first heat storage medium and the second heat storage medium, so that the heat energy is stored in the first heat storage assembly and the second heat storage assembly; the heat exchange working medium after being heated enters the low-temperature side of the third heat exchanger and absorbs the heat of the third heat storage medium at the high-temperature side of the third heat exchanger, and the heat exchange working medium with the temperature increased back returns to the compressor for next circulation. The surplus electric power is converted into the kinetic energy of the compressor, the kinetic energy is converted into the heat energy of the heat exchange working medium, and then the heat energy is stored into the first heat storage assembly and the second heat storage assembly through the first heat exchanger and the second heat exchanger, so that the surplus electric power is effectively stored; meanwhile, the heat exchange working medium after being cooled is heated through the third heat storage assembly by utilizing low-temperature solar heat, so that the initial temperature of the heat exchange working medium entering the compressor is higher, the temperature can reach the required temperature when the heat exchange working medium enters the next cycle, the first heat storage assembly obtains high-temperature heat, and the heat can be reheated, thereby being beneficial to improving the electric heating energy storage efficiency.
Detailed Description
The present invention will be described in further detail with reference to the accompanying drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting of the invention. It should be further noted that, for the convenience of description, only some of the structures related to the present invention are shown in the drawings, not all of the structures.
In the description of the present invention, unless expressly stated or limited otherwise, the terms "connected," "connected," and "fixed" are to be construed broadly, e.g., as meaning permanently connected, removably connected, or integral to one another; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.
In the present invention, unless otherwise expressly stated or limited, "above" or "below" a first feature means that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact with each other via another feature therebetween. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.
In the description of the present embodiment, the terms "upper", "lower", "left", "right", and the like are used based on the orientations and positional relationships shown in the drawings only for convenience of description and simplification of operation, and do not indicate or imply that the referred device or element must have a specific orientation, be configured and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used only for descriptive purposes and are not intended to have a special meaning.
As shown in fig. 1, the present embodiment provides a heat pump energy storage system, which is configured to convert surplus electric power of a new energy power generation device into thermal energy for storage, and the heat pump energy storage system includes a motor 10, a compressor 1, a first heat exchanger 2, a second heat exchanger 3, a turbine assembly 4, a third heat exchanger 5, a first heat storage assembly 6, a second heat storage assembly 7, and a third heat energy assembly 8. The surplus power is input into the motor 10, and the motor 10 is connected to the compressor 1 to drive the compressor 1 to work. Specifically, surplus electric power is transmitted to the motor 10, the motor 10 is connected to the compressor 1, and the motor 10 drives the compressor 1 to operate. The compressor 1, the high-temperature side of the first heat exchanger 2, the high-temperature side of the second heat exchanger 3, the turbine assembly 4 and the low-temperature side of the third heat exchanger 5 are sequentially communicated in series through heat exchange working medium pipelines to form a heat exchange loop; the first heat storage assembly 6 is communicated with the low-temperature side of the first heat exchanger 2 through a first heat storage medium pipeline to form a first heat storage loop, and a first heat storage medium flows through the first heat storage medium pipeline; the second heat storage assembly 7 is communicated with the low-temperature side of the second heat exchanger 3 through a second heat storage medium pipeline to form a second heat storage loop, and a second heat storage medium flows through the second heat storage medium pipeline; the third heat storage assembly 8 is communicated with the high-temperature side of the third heat exchanger 5 through a third heat storage medium pipeline to form a third heat storage loop, and a third heat storage medium flows through the third heat storage medium pipeline.
When the new energy power generation amount is surplus, surplus electric power is stored in the power storage device and is input to the motor 10 through the power storage device, the motor 10 drives the compressor 1 to work, namely, the surplus electric power is converted into kinetic energy, a heat exchange working medium is pressurized and heated through the compressor 1, namely, the kinetic energy of the compressor 1 is converted into heat energy of the heat exchange working medium, then the heat exchange working medium enters the high-temperature side of the first heat exchanger 2 and transfers the heat to a first heat storage medium positioned on the low-temperature side of the first heat exchanger 2, and therefore the heat is stored in the first heat storage assembly 6; the heat exchange working medium after exchanging heat with the first heat storage medium enters the high-temperature side of the second heat exchanger 3, and the residual heat is continuously transferred to the second heat storage medium at the low-temperature side of the second heat exchanger 3, so that the heat is stored in the second heat storage assembly 7; the reheated heat exchange working medium enters the low-temperature side of the third heat exchanger 5 and absorbs the heat of the third heat storage medium at the high-temperature side of the third heat exchanger 5, and the heat exchange working medium with the temperature increased back returns to the compressor 1 for next circulation. Surplus electric power is converted into kinetic energy of the compressor 1, the kinetic energy is converted into heat energy of a heat exchange working medium, and then the heat energy is stored into the first heat storage assembly 6 and the second heat storage assembly 7 through the first heat exchanger 2 and the second heat exchanger 3, so that the surplus electric power is effectively stored; the heat exchange working medium after being cooled is heated through the third heat storage assembly 8, so that the initial temperature of the heat exchange working medium entering the compressor 1 is higher, the temperature of the heat exchange working medium entering the first heat exchanger 2 can reach the required temperature, reheating can be carried out, the electric heating energy storage efficiency is improved, and the application range is wide.
Preferably, the heat exchange working medium adopts air; the first heat storage medium adopts fused salt, and the maximum heating temperature can reach more than 400 ℃; the second heat storage medium adopts heat conduction oil, and the maximum heating temperature is about 320 ℃; the third heat storage medium adopts normal pressure water. Of course, in other embodiments, other heat exchange working mediums and heat storage mediums can be adopted according to the needs. Optionally, the pressure ratio of the compressor 1 is 6-12, and in the present embodiment, the pressure ratio of the compressor 1 is 9.
Preferably, a valve is arranged in each loop, and the on-off of the heat exchange working medium and the heat storage medium can be controlled by controlling the opening and closing of the valve.
In order to enable the heat exchange working medium to smoothly supply heat for the next time, the temperature of the heat exchange working medium is raised through the third heat storage assembly 8 before the heat exchange working medium enters the compressor 1, so that the initial temperature of the heat exchange working medium is increased, and the temperature of the heat exchange working medium compressed by the compressor 1 can reach the required temperature. Specifically, the third heat storage assembly 8 includes a third cold tank 81, a solar heat collection device 82 and a third hot tank 83, and the third cold tank 81, the solar heat collection device 82, the third hot tank 83 and the high-temperature side of the third heat exchanger 5 are sequentially communicated in series through a third heat storage medium pipeline to form the third heat storage loop.
When the solar heat collection device 82 works under illumination, the third heat storage medium in the third cold tank 81 enters the solar heat collection device 82 to be heated and then enters the third hot tank 83 to be stored, when the heat exchange working medium needs to be heated, the third heat storage medium enters the high-temperature side of the third heat exchanger 5 to exchange heat with the heat exchange working medium, and the heated third heat storage medium returns to the third cold tank 81 to be circulated for the next time. Optionally, the solar heat collection device 82 heats the third heat storage medium at a temperature in the range of 80 ℃ to 100 ℃.
Further, the heat pump energy storage system further comprises a thermal power generation device 9, and the thermal power generation device 9 is respectively communicated with the first heat storage assembly 6 and the second heat storage assembly 7. When the power utilization peak period is reached, the thermal power generation device 9 is started, the heat stored in the first heat storage assembly 6 and the second heat storage assembly 7 is used by the thermal power generation device 9, and the heat is converted into electric energy through the thermal power generation device 9. The surplus electric power is converted into the heat energy for storage, and the stored heat energy is converted into the electric energy for power generation in the power utilization peak period, so that the electric energy is stored and taken at any time, and the electric energy is saved.
Preferably, the thermal power generation device 9 adopts a turbine power generation system, so that the efficiency is high, and the operation is safe and reliable.
Specifically, the first heat storage assembly 6 includes a first cold tank 61 and a first hot tank 62, and the first cold tank 61, the low-temperature side of the first heat exchanger 2, and the first hot tank 62 are sequentially communicated in series through a first heat storage medium pipe to form the first heat storage loop. The second heat storage assembly 7 comprises a second cold tank 71 and a second hot tank 72, and the second cold tank 71, the low-temperature side of the second heat exchanger 3 and the second hot tank 72 are sequentially communicated in series through a second heat storage medium pipeline to form the second heat storage loop. The thermal power generation device 9 is communicated with the first heat storage medium pipeline and is positioned between the inlet of the first cold tank 61 and the outlet of the first hot tank 62, and is also communicated with the inlet of the second cold tank 71 and the outlet of the second hot tank 72 through the second heat storage medium pipeline.
When surplus electric power needs to be converted into heat energy for storage, the first heat storage medium absorbs the heat of the heat exchange working medium at the high-temperature side of the first heat exchanger 2 at the low-temperature side of the first heat exchanger 2, the second heat storage medium absorbs the heat of the heat exchange working medium at the high-temperature side of the second heat exchanger 3 at the low-temperature side of the second heat exchanger 3, and then the first heat storage medium and the second heat storage medium respectively enter the first heat tank 62 and the second heat tank 72 for storage; when the peak power consumption period is reached, the first heat storage medium in the first hot tank 62 and the second heat storage medium in the second hot tank 72 are both conveyed to the thermal power generation device 9, the thermal power generation device 9 converts the heat of the first heat storage medium and the second heat storage medium into electric energy, and the heated first heat storage medium and the heated second heat storage medium respectively enter the first cold tank 61 and the second cold tank 71 to wait for the next heat absorption and energy storage.
In order to recover more kinetic energy, the turbine assembly 4 includes a high-pressure turbine 41 and a low-pressure turbine 42, the high-pressure turbine 41 is communicated between the high-temperature side of the second heat exchanger 3 and the low-temperature high-pressure side of the third heat exchanger 5 through a heat exchange working medium pipeline, the low-pressure turbine 42 is communicated between the low-temperature high-pressure side and the low-temperature low-pressure side of the third heat exchanger 5 through a heat exchange working medium pipeline, and the high-pressure turbine 41 and the low-pressure turbine 42 are respectively connected to the compressor 1 in a transmission manner to provide kinetic.
The temperature of the heat exchange working medium is reduced after twice heat supply, the cooled heat exchange working medium enters the high-pressure turbine 41 along the heat exchange loop to perform first expansion work, the work of expansion work is transmitted to the compressor 1, then the heat exchange working medium enters the low-temperature high-pressure side of the third heat exchanger 5 to absorb the heat of a third heat storage medium at the high-temperature side of the third heat exchanger 5, and the temperature is increased; the heated heat exchange working medium enters the low-pressure turbine 42 to perform secondary expansion work, and the work of expansion work is transmitted to the compressor 1; because the heat exchange working medium absorbs heat and is heated by the third heat exchanger 5 before entering the low pressure turbine 42, the low pressure turbine 42 can provide more power for the compressor 1 after the heat exchange working medium enters the low pressure turbine 42. The heat exchange working medium after being cooled and depressurized by the low-pressure turbine 42 enters the low-pressure low-temperature side of the third heat exchanger 5 to absorb heat of the third heat storage medium at the high-temperature side of the third heat exchanger 5 again, and the temperature is raised again. The heat exchange working medium after temperature rise enters the compressor 1 to start the next cycle for heat supply, and the temperature of the heat exchange working medium after being compressed by the compressor 1 can be raised to the required high temperature due to the temperature rise of the heat exchange working medium before entering the compressor 1, so that the energy storage efficiency is improved.
In this embodiment, the isentropic efficiency of the compressor 1 is 84%, the isentropic efficiency of the high-pressure turbine 41 is 90%, the isentropic efficiency of the low-pressure turbine 42 is 90%, and the net power generation efficiency of the thermal power generation device 9 is 37%, and the electricity-electricity conversion efficiency of the heat pump energy storage system provided in this embodiment can reach 63%.
Illustratively, the compressor 1 boosts 0.5MPa air to 4.5MPa, simultaneously raises the air temperature to about 453 ℃, the temperature of the heat exchange working medium is reduced to 280 ℃ after the first heat supply, the temperature of the first heat storage medium is raised to 440 ℃, the temperature of the heat exchange working medium is reduced to 100 ℃ after the second heat supply, the temperature of the second heat storage medium is raised to 270 ℃, the heat exchange working medium after the second heat supply enters the high-pressure turbine 41 to be reduced to 1.6MPa, the temperature is reduced to about 15 ℃, the solar heat collection device 82 raises the temperature of the third heat storage medium to 95 ℃, the temperature of the heat exchange working medium after the temperature reduction absorbs the heat of the third heat storage working medium, then the heat exchange working medium enters the low-pressure turbine 42 to be reduced to 0.6MPa, the temperature is reduced to about 15 ℃ again, and finally the temperature of the heat exchange working medium absorbs. Of course, in other embodiments, the operating state of each device may be adjusted according to the surplus power amount.
The following is the working process of the heat pump energy storage system provided by this embodiment:
when the solar heat collection device 82 works under illumination, the third heat storage medium in the third cold tank 81 is input into the solar heat collection device 82, heated and then input into the third hot tank 83 for storage;
when the new energy power generation amount is surplus, surplus power is input into the motor 10, the motor 10 drives the compressor 1 to work, the heat exchange working medium is pressurized and heated, then the heat exchange working medium is input into the high-temperature side of the first heat exchanger 2, at the moment, the first heat storage medium in the first cold tank 61 is input into the low-temperature side of the first heat exchanger 2 to absorb heat of the heat exchange working medium, and the heated first heat storage medium is input into the first hot tank 62 to be stored;
the heat exchange working medium is continuously input to the high-temperature side of the second heat exchanger 3 along the heat exchange loop, at the moment, the second heat storage medium in the second cold tank 71 is input to the low-temperature side of the second heat exchanger 3 to absorb the heat of the heat exchange working medium, and the heated second heat storage medium is input to the second hot tank 72 to be stored;
the heat exchange working medium is continuously input to the high-pressure turbine 41 along the heat exchange loop to be subjected to pressure reduction and temperature reduction, and then enters the low-temperature high-pressure side of the third heat exchanger 5, and at the moment, the third heat storage medium in the third heat tank 83 is input to the high-temperature side of the third heat exchanger 5 to provide heat for the heat exchange working medium;
the heated heat exchange working medium is input into the low-pressure turbine 42 to be depressurized and cooled again, and then enters the low-temperature low-pressure side of the third heat exchanger 5 to absorb the heat of the third heat storage medium again, so that the temperature is raised again; the heat exchange working medium after the two pressure drops and temperature rises returns to the compressor 1, and the next cycle heat exchange is started after the temperature and the pressure rise are carried out again.
During the peak period of electricity utilization, the thermal power generation device 9 is started, the first heat storage medium in the first heat tank 62 and the second heat storage medium in the second heat tank 72 are respectively input into the thermal power generation device 9, and the thermal power generation device 9 converts the heat of the first heat storage medium and the second heat storage medium into electric energy;
the first heat storage medium and the second heat storage medium after releasing heat are respectively input into the first cold tank 61 and the second cold tank 71 to wait for the next cycle of heat storage.
The heat pump heat storage system provided by the embodiment utilizes low-temperature solar heat and converts the low-temperature solar heat into high-temperature heat through the heat pump, so that more high-temperature heat energy is generated by utilizing electric power in the energy storage process, and the electricity-electricity conversion efficiency of the heat pump heat storage system is improved.
It is to be noted that the foregoing is only illustrative of the preferred embodiments of the present invention and the technical principles employed. It will be understood by those skilled in the art that the present invention is not limited to the particular embodiments described herein, but is capable of various obvious changes, rearrangements and substitutions as will now become apparent to those skilled in the art without departing from the scope of the invention. Therefore, although the present invention has been described in greater detail by the above embodiments, the present invention is not limited to the above embodiments, and may include other equivalent embodiments without departing from the spirit of the present invention, and the scope of the present invention is determined by the scope of the appended claims.