CN116291788A - Isothermal compression and expansion open air cycle engine and power generation system - Google Patents

Abstract

An air working medium thermodynamic cycle engine utilizes the heat energy of heat storage equipment as power to realize the output of mechanical energy. The main technical characteristics are as follows: in the process of converting heat energy into mechanical energy, the technical scheme of multistage small-temperature-difference boost compression and multistage small-temperature-difference buck expansion is adopted to approximately realize an isothermal compression process and an isothermal expansion process, so that higher thermodynamic cycle efficiency is obtained. The technology is particularly suitable for thermal energy power generation application (such as solar photo-thermal power generation and peak regulation and heat storage power generation of a nuclear power plant of a thermal power plant) with limited maximum temperature of a heat source, and compared with the traditional steam power generation cycle utilizing heat storage, the technology has the characteristics of high system thermal efficiency, simple process and low manufacturing cost.

Description

Isothermal compression and expansion open air cycle engine and power generation system

Technical Field

The invention belongs to the technical field of engines, and particularly relates to an engine technology for solar photo-thermal power generation.

Background

The power generation equipment applied to the solar tower type photo-thermal power generation system adopts a traditional steam power cycle power generation mode.

The solar photo-thermal device of the photo-thermal power generation system can only generally provide medium temperature of about 560 ℃, and after heat exchange, the temperature of steam obtained at the power generation side is about 290 ℃, so that the steam power cycle of the power generation equipment can only work under the working condition of superheated steam power generation cycle with lower temperature and pressure, and the thermal efficiency of the whole system is relatively low.

Disclosure of Invention

In order to improve the state that the traditional steam power cycle is low in efficiency in the existing photo-thermal power generation system, the invention provides open air cycle engine equipment with working medium approximately performing isothermal compression and isothermal expansion, compared with the prior art, the open air cycle engine equipment can remarkably improve the efficiency, has other beneficial effects in various aspects, and is specifically described as follows:

an engine device comprises an engine rotor, a radiator, a heater, a heat regenerator, a heat source device, a control device and the like;

the engine rotor comprises a compressor, an expander and a rotor shaft, wherein the compressor and the expander are coaxially connected in series by the rotor shaft;

the working medium of the engine equipment adopts air;

the heat source equipment is a solar photo-thermal heat storage system or a high-temperature heat storage system with the heat storage temperature similar to that of the solar photo-thermal heat storage system;

the power of the working process of the engine equipment is derived from the heat energy stored by the heat source equipment;

the engine working medium thermodynamic cycle consists of an approximate isothermal compression process, an isobaric heating process, an approximate isothermal expansion process and an isobaric cooling process which are sequentially completed;

the radiator, the heater and the heat regenerator are all counterflow heat exchanger equipment or cross-flow heat exchanger equipment.

Further, the compressor adopts a centrifugal air compressor or an axial-flow air compressor, and the whole set of compressor adopts a multistage compression mechanism to be connected in series; a compressed working medium pipeline is arranged between each two stages of compression mechanisms; two ends of the compressed working medium pipeline are respectively connected with a working medium outlet of the former-stage compression mechanism and a working medium inlet of the latter-stage compression mechanism.

Further, the radiator adopts a heat exchanger of engine working medium and atmosphere, the radiator is arranged on a compressed working medium pipeline between each two stages of compression mechanisms, and a hot side inlet/outlet of the radiator is respectively connected to an outlet of a previous stage of compression mechanism and a working medium inlet of a next stage of compression mechanism; the inlet/outlet of the cold side is communicated with the atmosphere.

Optionally, the radiator adopts an engine working medium and water heat exchanger, is arranged on a compressed working medium pipeline between each two stages of compression mechanisms, and the hot side inlet/outlet of the radiator is respectively connected to the outlet of the last stage of compression mechanism and the working medium inlet of the next stage of compression mechanism; the cold side inlet/outlet communicates with the cold water source outlet/inlet.

Further, the expansion machine adopts a turbine type, and the whole expansion machine is formed by connecting multiple expansion mechanisms in series; an expansion working medium pipeline is arranged between every two stages of expansion mechanisms; and two ends of the expansion working medium pipeline are respectively connected with a working medium outlet of the former-stage expansion mechanism and a working medium inlet of the latter-stage expansion mechanism.

Further, the heater adopts an engine working medium and heat source heat transfer medium heat exchanger, and is arranged on an expansion working medium pipeline between each two stages of expansion mechanisms and/or a working medium pipeline between the final stage compressor and the first stage expansion mechanism; the inlet/outlet of the hot side of the heater is connected to the outlet/inlet of the heat output pipe of the heat source apparatus of claim 1, respectively; the cold side inlet/outlet of the heater is connected with the inlet of the front-stage expander outlet (and/or the outlet of the final-stage compressor)/the rear-stage expansion mechanism (and/or the first-stage expansion mechanism) respectively.

Further, after each stage of compression mechanism of the compressor compresses the working medium, the temperature rise of the working medium is between 20 ℃ and 60 ℃.

Further, after each stage of expansion mechanism of the expander expands the working medium, the temperature drop of the working medium is controlled between 20 ℃ and 60 ℃.

Further, the whole set of engine equipment also comprises a set of heat-returning heat exchangers, namely a heat regenerator for short, wherein a cold side inlet of the heat-returning heat exchangers is connected to a working medium outlet of the final-stage compression mechanism, and a cold side outlet of the heat-returning heat exchangers is connected to a working medium inlet of the first-stage heater; the hot side inlet of the expansion mechanism is connected to the working medium outlet of the final expansion mechanism, and the hot side outlet is directly communicated with the atmosphere.

10. Preferably, one, part or all of the radiator, the heater and the regenerator is a heat pipe exchanger.

Further, the whole set of generator equipment also comprises a set of engine control device, the control device adopts a DCS control system, and the control device collects working parameters of all parts of the generator equipment, including but not limited to temperature, pressure, flow, stress, displacement, vibration, position, current, voltage, resistance, frequency and power, and controls and protects the operation of all the parts according to related parameters and control targets.

As described above, in the engine apparatus, since the compressor is divided into a plurality of stages, and the temperature rise of each stage of compression is limited to a small temperature difference value of 20 to 60 ℃, and after each compression, the temperature of the compressed working medium is lowered by the radiator, which is similar to the realization of the process of "isothermal compression"; by adopting a similar method, the process of approximate isothermal expansion of the working medium in the expansion process is realized. This makes the overall thermodynamic process a process relatively close to the "carnot cycle" and, therefore, a relatively high system thermal efficiency can be achieved.

By using a multistage expansion with multistage heating, the working medium can be maintained at a higher temperature and a higher average temperature throughout the expansion process than in a single stage expansion or a few stages of expansion processes. According to the carnot cycle principle, the higher the temperature, the higher the efficiency of the thermodynamic system. Similarly, the compression process is kept at a lower temperature through multistage compression and heat dissipation cooling, so that approximate isothermal compression is realized, and the efficiency of a thermodynamic system is improved.

The potential for the efficiency improvement of the present invention can be appreciated by comparing the highest efficiency of the theoretical cycle. The conventional working conditions of the solar photo-thermal power generation system are taken as examples for comparison and explanation.

The temperature of a heat medium of the solar photo-thermal system is about 565 ℃, at the temperature, the temperature of steam which can be obtained by a steam turbine of the power generation equipment is about 290 ℃, and the ultimate thermal efficiency of the traditional photo-thermal power generation system is as follows assuming that the ambient temperature is 30 ℃ and the corresponding condensed water temperature of the steam power generation cycle is about 55 ℃):

1-(55+273)/(290+273)≈41.7%

when the technical scheme of the invention is adopted, when the temperature of the solar heat medium is 565 ℃, the inlet/outlet temperature of the expander of the engine is not difficult to reach more than 380/410 ℃, calculated according to the average temperature 395 ℃, and likewise, the ambient temperature is 30 ℃, the inlet/outlet temperature of the compressor is not difficult to reach 50/80 ℃, and the average temperature is 65 ℃, so that the ultimate heat efficiency of the power generation system is as follows:

1-(65+273)/(395+273)≈49.4%。

if the solar heat storage system adopts a phase-change heat storage medium, the average expansion temperature of an expander of the generator has the potential of reaching 450 ℃, and if the average expansion temperature is calculated according to 450 ℃, the ultimate thermal efficiency of the power generation system is as follows when the ambient temperature is 30 ℃:

1-(65+273)/(450+273)≈53.3%。

therefore, compared with the traditional solar photo-thermal power generation equipment, the engine provided by the invention has the potential of greatly improving the solar heat energy utilization efficiency.

The engine equipment directly uses air as working medium, and the whole cycle is open cycle, so that even if the engine has certain leakage in the working process, the engine has little influence on the efficiency or other aspects of the system, thereby reducing the precision requirements on the manufacture and assembly of related parts and being beneficial to reducing the manufacturing cost and the later maintenance cost.

By adopting the technical scheme of the invention, the highest working pressure of the system is about 2.2MPa, and compared with the maximum working pressure (about 20 MPa) of the traditional solar photo-thermal power generation equipment, the system has larger reduction, which is beneficial to reducing the manufacturing cost of the equipment.

The working process of the generator is similar to that of a gas turbine, so that the generator also has the capability of quick start and quick stop; the function is also beneficial to improving the heat energy utilization efficiency of the solar photo-thermal system.

By cooling the working medium (air) multiple times during air compression, the temperature of the working medium is kept close to normal temperature, so that the compression mechanism is always kept at a lower working temperature, which can achieve various beneficial effects including but not limited to: wide material selection range, low cost and high reliability.

When the heat storage temperature of the heat source equipment is reduced, the engine can still work normally under the deviation design working condition, which is beneficial to improving the continuous working time of the engine equipment and stabilizing the power supply capacity of the power grid, namely, the stable work of the power grid.

Drawings

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

Fig. 1 is a schematic diagram of the structure and principle of an engine system with basic thermodynamic cycle and sensible heat change process of a heat source heat storage medium in the heat storage and release process.

FIG. 2 is a graph of temperature versus pressure operating conditions for a typical working fluid thermodynamic cycle process.

Fig. 3 is a schematic diagram of the structure and principle of an engine system with a heat regenerator installed in the thermodynamic cycle and a heat source heat storage medium in the sensible heat change process in the heat storage and release process.

Fig. 4 is a schematic structural diagram of a multi-stage integral heat pipe radiator.

Fig. 5 is a schematic view of the structural principle of the multi-stage integral heat pipe heater.

Fig. 6 is a schematic structural diagram of a multi-stage integral heat pipe regenerator.

Fig. 7 is a schematic structural diagram of a heat pipe exchanger unit for a regenerator and a radiator.

Fig. 8 is a schematic structural diagram of a heat pipe exchanger unit for a heater.

Fig. 9 is a schematic diagram of an engine system structure and principle of a thermodynamic cycle equipped with a regenerator, wherein a phase change heat storage material is adopted as a heat source heat storage medium, and a phase change material is also adopted as a heat transmission medium of a heat source device.

Fig. 10 is a schematic diagram of the structural principle of the water-cooled multistage integral heat pipe radiator.

The reference numerals in the above figures represent the following meanings:

100. engine rotor

110. Compressor with a compressor body having a rotor with a rotor shaft

111. First-stage compressor

112. Secondary compressor

113. Intermediate stage compressor

114. Final compressor

120. Expansion machine

121. First-stage expander

122. Secondary expander

123. Intermediate stage expander

124. Final stage expander

130. Rotor shaft

200. Radiator

210. First-stage radiator

220. Secondary radiator

230. Intermediate stage radiator

240. Final radiator

300. Heater

310. First-stage heater

320. Secondary heater

330. Intermediate stage heater

340. Final stage heater

400. Heat regenerator

500. Heat source equipment

510. Heat output pipeline

600. Engine control device

700. Generator device

800. Power generation control system

Description of the embodiments

In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be described in detail below.

It will be apparent that the described embodiments are only some, but not all, embodiments of the invention.

All other embodiments, based on the examples herein, which are within the scope of the invention as defined by the claims, will be within the scope of the invention as defined by the claims. In order that the embodiments may be more readily understood, various embodiments or methods of implementing the invention are provided below to illustrate the relevant devices, modules, functions of the invention.

Fig. 1 is a diagram of a thermal storage power generation system with various components required for basic thermodynamic cycle, a thermal storage medium of a heat source device 500, and an open air cycle during sensible heat change during heat storage, and a typical application is also indicated in the diagram.

In order for the reader of this example to quickly understand the embodiments of the present invention, the working principle expressed in fig. 1 will be first described.

As shown in fig. 1, the engine mainly includes: an engine rotor 100 composed of a compressor 110, an expander 120, a rotation shaft 130, a radiator 200, a heater 300, a regenerator 400, a heat source device 500, and connecting lines therebetween.

The compressor 110 is used for sucking working medium air, compressing the working medium air and boosting the pressure of the working medium; the radiator 200 functions to radiate heat generated from the compressor 110 to the outside; the heater 300 functions to input heat of the heat source device 500 into the working medium; the function of the expander 120 is to convert heat input by the heat source device 500 into mechanical energy output.

It can be seen that the thermodynamic cycle working medium in the working process of the engine is air.

The duty cycle of the whole set of generator equipment consists of 2 approximate isothermal processes (isothermal compression and isothermal expansion) and 2 isobaric processes (isobaric warming and isobaric cooling), see fig. 2. Four thermodynamic processes are described next.

1 approximate isothermal compression process:

this is the "1-2 process" of fig. 2, in which the compressor 110 draws air from the atmosphere, the air drawn being "working medium" air;

the compressor compresses working medium, and the temperature of the working medium rises;

in order to avoid too much temperature rise of the working medium, the temperature of the working medium is reduced by utilizing the radiator 200, and heat in the working medium is finally emitted to the atmosphere;

the compressor 110 is composed of a multi-stage compression mechanism, and the pressure of the working medium is gradually increased by multi-stage compression, so that the required operating pressure is finally reached.

The main purpose of using multi-stage compression is: the temperature of the compression process is prevented from rising too high because we have to achieve "near" isothermal compression. The entire compression process is completed by the compressor 110.

To achieve near isothermal compression, a heat sink 200 is employed to dissipate the heat of compression of each stage of compression mechanism into the external atmosphere; for this purpose, a radiator is installed between each two stages of compression mechanisms to radiate compression heat in time.

As shown in fig. 2, assuming that the outdoor air temperature is 30 ℃, the temperature at which the compression of the first-stage compressor 111 is completed may be set at 80 ℃, i.e., the compression temperature rise of the first-stage compressor 111 is 50 ℃;

the temperature of the working medium can be reduced to 50 ℃ by using the primary radiator 210, and then the working medium enters the secondary compressor 112; after compression by the secondary compressor 112, the temperature of the working fluid rises to 80 ℃, and then enters the secondary radiator 220; after passing through the secondary radiator 220, the temperature is again reduced to 50 ℃;

the working fluid then passes through the multi-stage intermediate stage compressor 113 and the multi-stage intermediate stage radiator 230, with the working fluid temperature likewise varying between 80 ℃ (i.e., 353K) and 50 ℃ (323K). The difference between 80 ℃ and 50 ℃ is 30 ℃ (30K), the average variation amplitude is, with respect to the average temperature of the compression process ((353k+323K)/2=338K): 30/338 is approximately equal to 8.9%, so the temperature change amplitude of the working medium in the whole compression process is not large, and the isothermal compression process can be approximately considered. Of course, if the temperature variation is controlled to be 70 ℃ and 50 ℃, the relative variation of the temperature can be reduced to (70-50)/((343+323)/2) ≡6%, and the approximation of the isothermal process is better.

The temperature of the working fluid after compression by the final compressor 114 is 80 ℃.

2 equal pressure heating process

After the compression of the working medium is finished, the working medium enters a first-stage heater 310, and the temperature is increased to 410 ℃; in this process, if the flow resistance of the working medium in primary heater 310 is ignored (which is very small relative to the working pressure of the working medium), then this process is an "isobaric process"; therefore, the whole process is an 'isobaric heating process'.

The heat required for this warming process originates from a heat source device 500, such as a solar thermal storage device.

Also indicated in FIG. 1 are reference inlet and outlet temperatures for the heat source side of each stage heater (310-340). More accurate heat source side inlet and outlet temperatures are required to be determined after more careful technical and economic comparisons in the actual design process.

3 approximate isothermal expansion process

This process is the 3-4 process of fig. 2.

After passing through the first-stage heater 310, the temperature of the working medium flowing out of the final-stage compressor 114 rises to 410 ℃, then enters the first-stage expander 121, and after expansion, the temperature is reduced to 380 ℃; the working medium then enters a secondary heater 320 and is heated to 410 ℃, and is expanded and cooled to 380 ℃ in a secondary expander 122; thereafter, this process is repeated in the plurality of intermediate stage heaters 330 and the intermediate stage expander 123; after passing through the final stage expander 124, the temperature is reduced to 380 ℃ and then vented to the atmosphere.

The final stage expander 124 may be designed as a more temperature reduced expander to reduce waste of thermal energy.

The heat energy of each stage heater comes from the heat source device 500. In fig. 1, the heat transfer medium temperature between the heat source device 500 and the heater 300 is set to 560 ℃ (outlet temperature of the heat source device 500) and 360 ℃ (inlet temperature of the heat source device 500), which are temperatures achievable by the solar photo-thermal heat storage system.

With reference to the previous description of the compression process, it will be appreciated that the overall expansion process is also an approximately isothermal process.

4 equal pressure cooling process

This is the 4-3 process in fig. 2.

In this process, the pressure of the working medium has been reduced to very close to atmospheric pressure and the working medium has been returned to the atmosphere; the working medium is continuously diffused in the atmosphere, and finally the temperature is reduced to be the same as the temperature of the atmosphere.

As shown in fig. 2, the working medium cycle of the engine according to the embodiment of the present invention includes 4 basic processes, in order: an approximate isothermal compression process, an isobaric warming process, an approximate isothermal expansion process, and an isobaric cooling process.

According to the carnot cycle theory, the efficiency of the thermodynamic cycle is highest if the compression and expansion processes can be isothermal, which obviously cannot be achieved, but, as we can approximately do, this has already been explained in the previous description of the engine operating principle, so that the engine arrangement according to the present embodiment has a higher thermal energy efficiency.

Also, according to the carnot cycle theory, the higher the high temperature or the lower the low temperature of the two isothermal processes, the higher the efficiency of the system cycle.

As can be seen from the previous engine operating principle, the average temperature during low temperature is: (80+50)/2=65 (°c) =338 (K), which is close to the condensation temperature of current photo-thermal power plants; while the average temperature of the high temperature process is

(380+410)/2=395(℃)=668(K)。

It can be seen that this temperature is increased considerably over the highest steam temperature of current photothermal power plants (about 290 ℃ C., 563K). Therefore, compared with the current photo-thermal power generation system, the power generation system has the advantage that the efficiency is remarkably improved.

The low temperature of the working medium thermodynamic cycle can be reduced by adopting a multi-stage compression mode, and the high temperature of the thermodynamic cycle can be improved by adopting a multi-stage expansion method, so that the efficiency of the thermodynamic cycle can be improved.

However, the increase of the compression stage number or the expansion stage number will increase the manufacturing cost of the equipment and also increase the volume of the compressor or the expander, so that reasonable balance needs to be found in the aspects of stage number, manufacturing cost, installation space and the like in the implementation process; in general, the installation size of the compressor and the expander is not a big problem, and since the size of the related heat exchanger device is large in the engine equipment system, balancing the number of stages with the manufacturing cost is a major aspect.

According to the analysis and calculation of the present inventors, the temperature rise value of each stage of compression (except the first stage of compression) is between 20 ℃ and 60 ℃, so that the optimized value can be found, and the final optimized value result is different according to the specific situation of each engineering. Similarly, the temperature drop value of each stage of expander is between 20 ℃ and 60 ℃ (except the final stage expander), and the temperature drop value can be determined after careful technical and economic comparison according to practical situations when the expander is implemented.

The engine rotor 100 is composed of a compressor 110, an expander 120, a rotor shaft 130 and the like; the compressor 110, the expander 120 are connected in series by a rotor shaft 130 to form a complete engine rotor.

A heat sink, i.e., a radiator 200, needs to be installed in each two-stage compression mechanism in order to radiate compression heat to the outside atmosphere.

The heat dissipation mode, namely air cooling or water cooling, can be selected according to the availability of water resource conditions of project implementation sites. If the water resource is abundant, a water-cooled radiator is preferably adopted; otherwise, air is used to cool the radiator.

FIG. 4 provides a schematic illustration of a configuration of an air-cooled radiator and typical operating parameters; FIG. 10 provides a schematic structural diagram of a water-cooled multi-stage integral heat pipe radiator and typical operating parameters; both types of heat sinks utilize a heat pipe heat transfer mode, which is a heat pipe type heat exchanger and is also a preferred heat exchange mode.

The primary side inlet of the radiator is connected with the working medium outlet of the former-stage compressor, and the primary side outlet is connected with the working medium inlet of the latter-stage compressor; if a water-cooled radiator is adopted, the inlet/outlet of the secondary side is respectively connected with the outlet/inlet of a cold water source; if an air-cooled radiator is adopted, the inlet and the outlet of the secondary side of the radiator are communicated with the atmosphere.

In fig. 1 and 4, optional working conditions of the radiator are also provided, wherein the working conditions of the primary side of the radiator are consistent with the working conditions of the compressor, and the working conditions of the secondary side are 30 ℃ for air inlet and 40 ℃ for air outlet, which is the case of adopting air cooling; if water cooling is carried out, the water inlet is 30 ℃ and the water outlet is 35 ℃.

The working condition is only used as a reference, and careful technical and economic optimization is still needed in practical implementation.

As shown in fig. 1, before the first-stage expander 121 and between each two stages of expanders, 1 set of heaters are respectively installed, and the heaters are heat exchangers of engine working medium and heat source heat release circulation medium, namely: the hot side of the heat exchanger is the circulating medium of the heat source device 500, possible circulating mediums include, but are not limited to, molten salt liquid, phase change fluid (liquid and gas), water vapor, carbon dioxide, etc., depending on the type of heat source; the cold side medium of the heat exchanger is engine working medium.

The working condition data of each heater are also provided in fig. 1 and 5, but only for reference, in actual implementation, detailed technical and economic analysis is still required according to the actual condition of the project.

The cold side working condition of the heater is adapted to the working condition of the expander (e.g. 410 ℃ and 380 ℃) and the hot side working condition is adapted to the working condition of heat accumulation and heat release of the heat source device, wherein the liquid supply temperature of the heat source device 500 is determined to be 560 ℃, the liquid return (or air return) temperature is determined to be 360 ℃ in fig. 1, which is a working condition parameter determined by combining the working condition of the current solar photo-thermal heat accumulation system.

In combination with the practical situation of the embodiment of the invention, the heater is preferably a heat pipe type heater; fig. 5 provides a schematic structural diagram of a multi-stage integral heat pipe heater, and fig. 8 is a schematic structural diagram of a heat exchange unit of the heater. As shown in fig. 8, the heat transfer coefficient is high due to the large heat capacity of the heat source side medium, so that the heat pipe evaporation section does not need to strengthen the heat transfer process; however, the working medium side (cold side) is air, and heat transfer enhancement is necessary by adopting heat exchange fins.

According to the operating parameters of the various devices or components identified in fig. 1, the temperature of the working fluid eventually flowing from the final expander 124 reaches 380 ℃, and if this high temperature air is directly vented to the atmosphere, it may cause a loss of thermal energy.

Although the design of the final expansion machine 124 may be modified to some degree by optimizing it, the temperature of the discharged working fluid may be reduced to some degree, for example, to 280 ℃, there is still waste of heat energy.

For this purpose, we can install a heat recovery device, i.e. "regenerator 400".

As shown in fig. 3, the regenerator is installed on a working fluid pipeline between the final stage compressor 114 and the first stage expander 121, wherein a cold side inlet is connected to a working fluid outlet of the final stage compressor 114, a cold side outlet is connected to a working fluid inlet of the first stage expander 121, a hot side inlet is connected to a working fluid outlet of the final stage expander 124, and the hot side outlet is directly opened to the atmosphere.

After the heat regenerator 400 is installed, heat recovery in working medium air with higher temperature at the outlet of the final-stage expansion machine 124 can be realized, the heat efficiency of the system is improved, and the heat transfer load of the first-stage heater 310 can be reduced.

The heat exchange medium at both sides of the regenerator 400 is air, the hot side is high-temperature low-pressure working medium air flowing out of the final-stage expander, and the cold side is high-pressure low-temperature working medium air flowing out of the final-stage compressor 114. Such operating characteristics should be considered in the design of regenerator 400.

In combination with the heat exchange characteristics of the regenerator 400, the regenerator 400 is preferably a heat pipe type heat exchanger.

Fig. 6 is a schematic structural diagram of a multi-stage integral heat pipe regenerator. As shown in the figure, the regenerator consists of a first-stage regenerator, a second-stage regenerator, a plurality of intermediate-stage regenerators and a last-stage regenerator. In the figure, the working condition parameters of the regenerators of each stage can be provided for reference. The reference structure of each stage regenerator is shown in fig. 7.

The heat source device 500 is a power source of the whole set of generators.

The main heat source devices suitable for the engine device of the present invention are various medium-high temperature heat storage devices such as: solar photo-thermal heat storage equipment, medium-high Wen Diaofeng heat storage equipment of nuclear power plants and thermal power plants, and the heat storage temperature of the heat storage equipment in the scenes is 300 ℃ to 700 ℃ or higher, so that the heat storage equipment is a heat source suitable for the generator equipment. Of course, this does not exclude the possibility, feasibility of the engine arrangement of the invention to use other heat sources.

The invention mainly provides a solar photo-thermal power generation system, namely a heat source system composed of a solar photo-thermal heat absorber and a heat storage and release device.

The hot side medium lines of the respective heaters are connected in parallel, i.e. the inlets of the respective heaters are connected to the circulation medium outlet of the heat source device 500, and the outlets thereof are connected to the circulation medium inlet of the heat source device 500.

The heat source device 500 may also be other types of heat storage devices, such as: peak regulation energy storage equipment of a thermal power plant or a nuclear power plant, which stores heat (in some cases, direct electric heat storage) by utilizing high-temperature steam of a thermal power unit or a nuclear power unit during low electricity load periods, releases stored heat energy during electricity load peak periods, and drives a generator 700 to generate electricity by utilizing the engine disclosed by the invention, so that power grid load balance is assisted, and even frequency modulation of a power grid is realized.

The foregoing mainly describes the application of the heat source apparatus 500 to the use of sensible heat storage media.

If the heat source device 500 is capable of storing heat using a medium-high temperature phase-change thermal storage medium, the engine device of the present invention will be expected to achieve higher thermal efficiency because the heat source device 500 can release heat at a higher average exothermic temperature.

Fig. 9 is a schematic diagram of an engine system structure and principle that a heat source heat storage medium adopts a phase change heat storage substance and a heat transmission medium of a heat source device also adopts a phase change substance, and the main difference between the diagram and fig. 1 and 3 is that the average heat release temperature of a heat release circulation medium of the heat source device 500 is higher, and the average temperature in a working medium expansion process is higher, so that the heat efficiency of an engine working cycle is higher.

The two ends of the rotor shaft of the engine can be connected with a power load machine, so that the mechanical energy output of the engine can be realized.

The most main mechanical energy output load equipment is the generator 700, and the generator 700 is connected with the engine to realize the output of mechanical energy of the engine to electric energy, which is the main function of the engine.

To further refine the embodiments of the present invention, a control scheme of the engine apparatus of the present embodiment is provided herein, that is: the engine equipment is provided with a set of control device 600, and a preferred control device is a DCS system, so that all components of the engine equipment can be controlled in a layered manner by using the DCS system, and the mutual influence among the controller devices is reduced. The DCS control system collects the operating parameters of the components of the starting apparatus including, but not limited to, temperature, pressure, flow, stress, displacement, vibration, position, current, voltage, resistance, frequency, power, and comprehensively controls and protects the operation of the components.

The main application scenario of the engine device of the present invention is power generation, in particular solar photo-thermal power generation, so as shown in fig. 1, 3 and 9, embodiments of the combination of the generator device 700 and the engine device of the present invention are provided, namely: the power generation and power generation internet surfing can be realized by coaxially connecting the power generator device 700 to one end of the power generator rotor and configuring the corresponding power generation control system 800.

Claims (12)

1. An engine device comprises an engine rotor, a radiator, a heater, a heat regenerator, a heat source device, a control device and the like;

the engine rotor comprises a compressor, an expander and a rotor shaft, wherein the compressor and the expander are coaxially connected in series by the rotor shaft; the working medium of the engine equipment is air;

the heat source equipment is a solar photo-thermal heat storage system or other high-temperature heat storage systems with heat storage temperature similar to that of the solar photo-thermal heat storage system;

the power of the working process of the engine equipment is derived from the heat energy stored by the heat source equipment;

the engine working medium thermodynamic cycle consists of an approximate isothermal compression process, an isobaric heating process, an approximate isothermal expansion process and an isobaric cooling process which are sequentially completed;

the radiator, the heater and the heat regenerator are all counterflow heat exchanger equipment or cross-flow heat exchanger equipment.

2. The compressor of claim 1 being of centrifugal or axial type and consisting of a cascade of multiple compression mechanisms; a compressed working medium pipeline is arranged between each two stages of compression mechanisms; and two ends of the compressed working medium pipeline are respectively connected with a working medium outlet of the previous stage compression mechanism and a working medium inlet of the next stage compression mechanism.

3. The radiator as claimed in claim 1 is a heat exchanger of engine working medium and atmosphere, and is installed on a compressed working medium pipeline between each two stages of compression mechanisms as claimed in claim 2, wherein a hot side inlet/outlet is respectively connected to an outlet of a previous stage of compression mechanism/a working medium inlet of a next stage of compression mechanism; the inlet/outlet of the cold side is communicated with the atmosphere.

4. The radiator as claimed in claim 1, which is a heat exchanger of engine working medium and water, and is installed on a compressed working medium pipeline between each two stages of compression mechanisms, wherein a hot side inlet/outlet is respectively connected to an outlet of a previous stage of compression mechanism/a working medium inlet of a next stage of compression mechanism; the cold side inlet/outlet communicates with the cold water source outlet/inlet.

5. The expander of claim 1 is of turbine type and is comprised of multiple stages of expansion mechanisms in series; an expansion working medium pipeline is arranged between every two stages of expansion mechanisms; and two ends of the expansion working medium pipeline are respectively connected with a working medium outlet of the former-stage expansion mechanism and a working medium inlet of the latter-stage expansion mechanism.

6. The heat transfer medium heat exchanger of claim 1, wherein the heat transfer medium heat exchanger is arranged on an expansion medium pipeline between each two stages of expansion mechanisms or a working medium pipeline between a final stage compression mechanism and a first stage expansion mechanism; the inlet/outlet of the hot side of the heater is connected to the outlet/inlet of the heat output pipe of the heat source apparatus of claim 1, respectively; the cold side inlet/outlet of the heater is connected to the inlet of the preceding stage expansion mechanism outlet (or the final stage compression mechanism outlet)/the following stage expansion mechanism (or the first stage expansion mechanism) as defined in claim 5, respectively.

7. The compressor of claim 1 and claim 2, wherein the temperature rise of the working medium after compression of the working medium by each stage of compression mechanism is between 20 ℃ and 60 ℃.

8. After the expansion mechanism of each stage of the expander of claim 1 and claim 5 expands the working medium, the temperature drop of the working medium is controlled to be between 20 ℃ and 60 ℃.

9. The regenerator of claim 1, wherein the cold side inlet is connected to a working fluid outlet of the final stage compression mechanism and the cold side outlet is connected to a working fluid inlet of the first stage heater; the hot side inlet of the expansion mechanism is connected to the working medium outlet of the final expansion mechanism, and the hot side outlet is communicated with the atmosphere.

10. One, part or all of the heat sink of claim 1, claim 3 and claim 4, the heater of claim 1 and claim 6, and the regenerator of claim 1 and claim 9 is a heat pipe heat exchanger.

11. The control device of claim 1 is a DCS control system that collects the operating parameters of the components of the generator apparatus including, but not limited to, temperature, pressure, flow, stress, displacement, vibration, position, current, voltage, resistance, frequency, power, and controls and protects the operation of the components based on the relevant parameters and control targets.

12. A power generation system comprising the engine apparatus and the generator apparatus of claim 1, and a power generation control system, the generator apparatus being coaxially connected with the engine rotor of claim 1; the power generation control system collects working parameters in the running process of the engine equipment, receives instruction information of the power grid dispatching system, and adjusts the rotating speed, frequency and output power of the engine rotor according to the parameters or the information, so that the output electric power of the whole device meets the instruction requirement of the power grid dispatching system.

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