CN112683093B - Heat accumulating type backheating supercritical carbon dioxide circulating system with valve switching - Google Patents

Abstract

The invention discloses a valve-switched regenerative regenerative supercritical carbon dioxide circulation system. The system includes a heating assembly, a power generation assembly and a heat storage assembly, wherein the heating assembly includes a storage tank, a pump connected to the storage tank, and a Heat source connected to the pump; power generation assembly, connected to the pump, including a turbine and a generator connected to the turbine; heat storage assembly, connected to the turbine, including a heat storage element, a cooler connected to the heat storage element, and a cooler connected The average heat exchange effect can reach 91.3%, and the investment and manufacturing cost of the regenerator is reduced by 50%. Considering the increased cost of additional valves and other equipment, a valve-switched regenerative regenerative supercritical carbon dioxide cycle system is adopted. Compared with the supercritical carbon dioxide circulation system using the printed pipeline heat exchanger, the overall benefit can be about 20%.

Description

A regenerative regenerative supercritical carbon dioxide cycle system with valve switching

technical field

The invention relates to the technical field of power cycles, in particular to a valve-switched regenerative regenerative supercritical carbon dioxide cycle system.

Background technique

With its high cycle efficiency and compact overall structure, the supercritical carbon dioxide Brayton cycle can be coupled with heat sources such as nuclear reactors, solar thermal, gas turbine waste heat, and traditional thermal power boilers.

The heat exchanger is one of the main equipments in the supercritical carbon dioxide Brayton cycle. The heat exchanger needs to meet at least the following requirements: (1) It can withstand higher temperature and pressure, and the maximum operating temperature range is 500°C to 700°C. Operating pressure 18 to 20MPa. (2) The overall size is small. In order to reduce the overall size of the system, the volume of the heat exchanger should be as small as possible. At present, printed circuit board heat exchanger (PCHE) is the main choice for supercritical carbon dioxide Brayton cycle system, but PCHE adopts photochemical etching and other processing technologies, which is difficult to process and has high investment cost.

At present, the regenerative heat exchanger has low investment cost and good heat exchange effect, and is widely used in the industrial field. Therefore, it is proposed to apply the regenerative heat exchanger to the supercritical carbon dioxide Brayton cycle system to reduce the amount of energy in the supercritical carbon dioxide cycle system. The processing difficulty and investment cost of the regenerator are of great significance to the large-scale application and development of supercritical carbon dioxide systems.

SUMMARY OF THE INVENTION

The purpose of this section is to outline some aspects of embodiments of the invention and to briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the abstract and title of the application to avoid obscuring the purpose of this section, abstract and title, and such simplifications or omissions may not be used to limit the scope of the invention.

In view of the problems existing in the existing valve-switched regenerative regenerative supercritical carbon dioxide circulation system, the present invention is proposed.

Therefore, the purpose of the present invention is to provide a valve-switched regenerative regenerative supercritical carbon dioxide cycle system, which can solve the problems of difficult processing and high investment cost of the regenerator in the current supercritical carbon dioxide cycle system.

In order to solve the above-mentioned technical problems, the present invention provides the following technical solutions: a valve-switched regenerative regenerative supercritical carbon dioxide cycle system, including a heating assembly, a power generation assembly, and a heat storage assembly, wherein the heating assembly includes a storage tank, and a heat storage assembly. A pump connected to the storage tank, and a heat source connected to the pump; a power generation assembly, connected to the pump, including a turbine and a generator connected to the turbine; a heat storage assembly, connected to the turbine, including A heat storage element, a cooler connected to the heat storage element, and a compressor connected to the cooler.

As a preferred solution of the valve-switched regenerative regenerative supercritical carbon dioxide circulation system of the present invention, wherein: the heating assembly, the power generation assembly and the heat storage assembly are connected through a pipeline.

As a preferred solution of the valve-switched regenerative regenerative supercritical carbon dioxide circulation system of the present invention, a first regulating valve and a first three-way valve are arranged between the pump and the heat source, and the first The three-way valve connects the first regulating valve, the heat source and the turbine.

As a preferred solution of the valve-switched regenerative regenerative supercritical carbon dioxide cycle system of the present invention, wherein: the heat storage element includes a first regenerator and a second regenerator, and the first regenerator A second three-way valve is connected between the heater, the second regenerator and the turbine.

As a preferred solution of the valve-switched regenerative regenerative supercritical carbon dioxide circulation system of the present invention, wherein: the first regenerator and the second regenerator are respectively provided with a filling port and a regenerative inlet regulating valve , a heat storage outlet regulating valve, a heat releasing inlet regulating valve and a heat releasing outlet regulating valve, and the first regenerator and the second regenerator are also placed with fillers.

As a preferred solution of the valve-switched regenerative regenerative supercritical carbon dioxide cycle system of the present invention, wherein: the regenerative inlet regulating valve of the first regenerator and the second regenerator is connected to the second three-way Valve connection, the heat storage outlet regulating valve and the cooler are connected through the third three-way valve, the heat releasing inlet regulating valve and the compressor are connected through the fourth three-way valve, and the heat releasing outlet regulating valve and the heat source are connected through the fifth three-way valve valve connection.

As a preferred solution of the valve-switched regenerative regenerative supercritical carbon dioxide circulation system of the present invention, wherein: the compressor is also connected with an electric motor.

As a preferred solution of the valve-switched regenerative regenerative supercritical carbon dioxide cycle system of the present invention, wherein: the heat source is a heat source with a temperature of ~°C, such as solar energy, nuclear reactor, industrial waste heat, etc.

As a preferred solution of the valve-switched regenerative regenerative supercritical carbon dioxide circulation system of the present invention, wherein: the filling degree of the filler ranges from . to ., and can be selected from corundum balls, cast ceramics and Alloy materials, etc.

As a preferred solution of the valve-switched regenerative regenerative supercritical carbon dioxide circulation system of the present invention, wherein: the first regenerator and the second regenerator are integrally formed and made of stainless steel.

Beneficial effects of the present invention:

Compared with the conventional supercritical carbon dioxide circulation system using a printed circuit board heat exchanger (PCHE), the valve-switched regenerative regenerative supercritical carbon dioxide circulation system proposed by the present invention has lower investment cost and less processing difficulty. It is beneficial to the construction and promotion of supercritical carbon dioxide Brayton cycle system in engineering.

The 10MW supercritical carbon dioxide Brayton cycle system is tested. The heat storage and regenerator box adopts 316 stainless steel tube, the heat storage filling material adopts 3mm stainless steel ball, the filling rate is 37%, the working pressure range is 7.4 ~ 15MPa, and the working temperature range is The temperature is 71℃～244℃. The heat exchange effect of the regenerative regenerator is tested. The results show that the average heat exchange effect can reach 91.3%, and the investment and manufacturing cost of the regenerator is reduced by 50%. Considering the increased valve Compared with the supercritical carbon dioxide cycle system using the printed pipeline heat exchanger, the regenerative regenerative supercritical carbon dioxide cycle system using valve switching can bring about 20% of the overall income.

Description of drawings

In order to illustrate the technical solutions of the embodiments of the present invention more clearly, the following briefly introduces the accompanying drawings used in the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained from these drawings without any creative effort. in:

FIG. 1 is a schematic diagram of the overall structure of the regenerative regenerative supercritical carbon dioxide cycle system with valve switching according to the present invention.

FIG. 2 is a schematic structural diagram of the regenerator of the regenerative regenerative supercritical carbon dioxide cycle system with valve switching according to the present invention.

Detailed ways

In order to make the above objects, features and advantages of the present invention more clearly understood, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention can also be implemented in other ways different from those described herein, and those skilled in the art can do so without departing from the connotation of the present invention. Similar promotion, therefore, the present invention is not limited by the specific embodiments disclosed below.

Second, reference herein to "one embodiment" or "an embodiment" refers to a particular feature, structure, or characteristic that may be included in at least one implementation of the present invention. The appearances of "in one embodiment" in various places in this specification are not all referring to the same embodiment, nor are they separate or selectively mutually exclusive from other embodiments.

Thirdly, the present invention is described in detail with reference to the schematic diagrams. When describing the embodiments of the present invention in detail, for the convenience of explanation, the cross-sectional views showing the device structure will not be partially enlarged according to the general scale, and the schematic diagrams are only examples, which should not be used here. Limit the scope of protection of the present invention. In addition, the three-dimensional spatial dimensions of length, width and depth should be included in the actual production.

Example 1

Referring to FIG. 1 , for the first embodiment of the present invention, a valve-switched regenerative regenerative supercritical carbon dioxide cycle system is provided. The system includes a heating assembly 100 , a power generation assembly 200 and a heat storage assembly 300 , wherein the heating The assembly 100 includes a storage tank 101, a pump 102 connected to the storage tank 101, and a heat source 103 connected to the pump 102; a power generation assembly 200, connected to the pump 102, including a turbine 201 and a turbine Generator 202 connected to 201; heat storage assembly 300, connected to the turbine 201, including a heat storage element 301, a cooler 302 connected to the heat storage element 301, and a compressor 303 connected to the cooler 302 .

The heating component 100 can heat the supercritical carbon dioxide working medium and provide carbon dioxide for the entire system, the power generation component 200 drives the generator 202 to generate electricity through the supercritical carbon dioxide, and the heat storage component 300 is used for absorbing and storing the heat of the supercritical carbon dioxide. The temperature is lowered and pressurized, and then returned to the heat source 103 for circulation.

The storage tank 101 stores supercritical carbon dioxide, the pump 102 drives the carbon dioxide to flow into the system, the heat source 103 heats the carbon dioxide, and the heated supercritical carbon dioxide working medium enters the turbine 201 to do work, and the turbine 201 drives the generator 202 to generate electricity, and the heat storage element 301 is used to absorb and store the heat of supercritical carbon dioxide, the cooler 302 cools the carbon dioxide, and then the carbon dioxide enters the compressor 303 for pressurization.

Example 2

1-2, it is the second embodiment of the present invention, which is different from the first embodiment in that the heating assembly 100, the power generation assembly 200 and the heat storage assembly 300 are connected by pipes. A first regulating valve 101a and a first three-way valve 101b are disposed between the pump 102 and the heat source 103, and the first three-way valve 101b is connected to the first regulating valve 101a, the heat source 103 and the turbine 201.

The heat storage element 301 includes a first regenerator 301a and a second regenerator 301b, and a second three-way valve 301c is connected between the first regenerator 301a, the second regenerator 301b and the turbine 201 . The first regenerator 301a and the second regenerator 301b are respectively provided with a filling port 301a-1, a heat storage inlet regulating valve 301a-2, a thermal storage outlet regulating valve 301a-3, and a heat releasing inlet regulating valve 301a-4. And the exothermic outlet regulating valve 301a-5, the first regenerator 301a and the second regenerator 301b are also filled with fillers 301a-6.

The heat storage inlet regulating valve 301a-2 of the first regenerator 301a and the second regenerator 301b is connected to the second three-way valve 301c, and the heat storage outlet regulating valve 301a-3 and the cooler 302 pass through the third three-way valve 301c. The through valve 301d is connected, the heat release inlet regulating valve 301a-4 is connected to the compressor 303 through the fourth three-way valve 301e, and the heat release outlet regulating valve 301a-5 is connected to the heat source 103 through the fifth three-way valve 301f.

The compressor 303 is also connected with an electric motor 303a. The heat source 103 is a heat source with a temperature of 400-750°C, such as solar energy, nuclear reactor, industrial waste heat, etc. The filling degree of the filler 301a-6 ranges from 0.3 to 0.5, and can be selected from corundum balls, cast ceramics and alloy materials. The first regenerator 301a and the second regenerator 301b are integrally formed and made of stainless steel.

Compared with Example 1, further, when the unit is started, the first regulating valve 101a is opened, and the supercritical carbon dioxide working medium flows into the system from the carbon dioxide storage tank 101 under the drive of the pump 102, and when the working medium is replenished, it is closed. The pump 102 and the first regulating valve 101a; the heat source 103 starts to heat the inflowing supercritical carbon dioxide working medium, and the heated supercritical carbon dioxide working medium enters the turbine 201 to do work, and drives the generator 202 to generate electricity; at this time, the first heat recovery The thermal storage inlet regulating valve 301a-2 and the thermal storage outlet regulating valve 301a-3 on the regenerator 301a are opened, the thermal storage inlet regulating valve 301a-2 and the thermal storage outlet regulating valve 301a-3 of the second regenerator 301b are closed, and the thermal storage inlet regulating valve 301a-2 and the thermal storage outlet regulating valve 301a-3 of the second regenerator 301b The side of the two-way valve 301c and the third three-way valve 301d connected to the first regenerator 301a is opened, the side connected to the second regenerator 301b is closed, and the heat release inlet regulating valve of the first regenerator 301a is closed. 301a-4 and the exothermic outlet regulating valve 301a-5 are closed, the exothermic inlet regulating valve 301a-4 and the exothermic outlet regulating valve 301a-5 of the second regenerator 301b are opened, and the fourth three-way valve 301d is connected to the first regenerator. The side connected to the regenerator 301a is closed, the side connected to the second regenerator 301b is opened, the side connected to the second regenerator 301b of the fifth three-way valve 301e is opened, and the side connected to the first regenerator 301a is opened. One side is closed.

The supercritical carbon dioxide working medium is heated by the heat source 103, enters the turbine 201 to perform work, and drives the generator 202 to generate electricity. The thermal storage inlet regulating valve 301a-2 enters the first regenerator 301a for thermal storage, the heat of the high-temperature supercritical carbon dioxide working medium is stored in the first regenerator 301a at a lower temperature, and the cooled supercritical carbon dioxide working medium passes through the first regenerator. The temperature of the heat storage outlet regulating valve 301a-3 of the cooler 301a flows into the cooler 302 and the temperature continues to decrease, the supercritical carbon dioxide after cooling enters the compressor 303 for pressurization, and the supercritical carbon dioxide working medium after the pressure rise passes through the fourth three-way valve 301d and the heat release inlet regulating valve 301a-4 of the second regenerator 301b flows into the second regenerator 301b. At this time, the second regenerator 301b has not undergone heat storage, and the second regenerator 301b only acts as a communication circuit. , so the supercritical carbon dioxide working medium flows out from the heat release outlet regulating valve 301a-5 through the second regenerator 301b, and enters the heat source 103 through the fifth three-way valve 301e for the next cycle.

After the unit is started for a period of time, the heat storage in the first regenerator 301a is completed, and the system performs valve switching. closed, the heat storage inlet regulating valve 301a-2 and the heat storage outlet regulating valve 301a-3 of the second regenerator 301b are opened, the second three-way valve 301c is closed with the side connected to the first regenerator 301a, and the The side connected to the second regenerator 301b is opened, the side connected to the first regenerator 301a of the third three-way valve 301c is closed, and the side connected to the second regenerator 301b is opened; The exothermic outlet regulating valve 301a-5 and the exothermic inlet regulating valve 301a-4 of the regenerator 301a are opened, the exothermic inlet regulating valve 301a-4 and the exothermic outlet regulating valve 301a-5 of the second regenerator 301b are closed, The side of the fourth three-way valve 301d connected to the first regenerator 301a is opened, the side connected to the second regenerator 301b is closed, and the side of the fifth three-way valve 301e connected to the first regenerator 301a is opened , the side connected to the second regenerator 301b is closed.

At this time, the entire process of the supercritical carbon dioxide working fluid is as follows: the supercritical carbon dioxide working fluid is heated by the heat source 103, enters the turbine 201 to perform work, and drives the generator 202 to generate electricity. The two-three-way valve 301c and the heat storage inlet regulating valve 301a-2 of the second regenerator 301b conduct heat storage, and the heat of the supercritical carbon dioxide working medium is stored in the second regenerator 301b to reduce the temperature. The temperature of the refrigerant flows into the cooler 302 through the heat storage outlet regulating valve 301a-3 and the temperature continues to decrease, the supercritical carbon dioxide after cooling enters the compressor 303 for pressurization, and the supercritical carbon dioxide working medium after the pressure rise passes through the fourth three-way valve 301d and 301d. The heat release inlet regulating valve 301a-4 of the first regenerator 301a flows into the first regenerator 301a, the supercritical carbon dioxide working medium absorbs the heat stored before the first regenerator 301a and the temperature rises, and the supercritical carbon dioxide working fluid after the temperature rises. The mass is discharged from the heat release outlet regulating valve 301a-5 of the first regenerator 301a, and continues the next cycle through the fifth three-way valve 301e and the heat source 103.

When the unit is running stably, the system switches according to the heat storage time of the first regenerator 301a and the second regenerator 301b. The regenerative regenerator switches to the heat release circuit for heat release; the other regenerative regenerator opens the valve on the heat storage side to store heat, and closes the valve on the heat release side; such a cyclic switch achieves the purpose of heat storage and heat recovery.

The regenerative regenerator box of the regenerative regenerator adopts stainless steel as the tube wall material, and the regenerative filler 301a-6 filled inside is a spherical heat storage filler with a diameter of 6mm. In the first regenerator 301a and the second regenerator 301b, the filling degree of the filling material in the heat storage and heat recovery tank is generally between 0.3 and 0.5, which can be adjusted according to the actual situation. The heat storage inlet regulating valve 301a-2 , the heat storage outlet control valve 301a-3, the heat release inlet control valve 301a-4 and the heat release outlet control valve 301a-5 correspond to the heat storage circuit side and heat release circuit side control valves in the whole system, and the whole heat storage type The regenerators are welded together to ensure the tightness of the system.

The rest of the structure is the same as that of Embodiment 1.

It is important to note that the construction and arrangement of the present application shown in the various exemplary embodiments are merely exemplary. Although only a few embodiments have been described in detail in this disclosure, those who refer to this disclosure will readily appreciate that many modifications are possible without materially departing from the novel teachings and advantages of the subject matter described in this application are possible (eg, changes in size, dimensions, structure, shape, and proportions of various elements, as well as parameter values (eg, temperature, pressure, etc.), mounting arrangement, use of materials, color, orientation, etc.). For example, elements shown as integrally formed may be constructed of multiple parts or elements, the positions of elements may be inverted or otherwise varied, and the nature or number or positions of discrete elements may be altered or varied. Accordingly, all such modifications are intended to be included within the scope of this invention. The order or sequence of any process or method steps may be varied or re-sequenced according to alternative embodiments. In the claims, any "mean-plus-function" clause is intended to cover the structures described herein as performing the recited function and not only structural equivalents but also equivalent structures. Other substitutions, modifications, changes and omissions may be made in the design, operation and arrangement of the exemplary embodiments without departing from the scope of the present invention. Therefore, the present invention is not limited to a particular embodiment, but extends to various modifications still falling within the scope of the appended claims.

Furthermore, in order to provide a concise description of example embodiments, all features of an actual implementation (ie, those that are not relevant to the best mode currently considered for carrying out the invention, or those that are not relevant for carrying out the invention, may not be described in order to provide a concise description of example embodiments) feature).

It should be appreciated that during the development of any actual implementation, such as in any engineering or design project, numerous implementation-specific decisions may be made. Such a development effort may be complex and time-consuming, but would be a routine undertaking of design, fabrication, and production without undue experimentation for those of ordinary skill having the benefit of this disclosure .

It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be Modifications or equivalent substitutions without departing from the spirit and scope of the technical solutions of the present invention should be included in the scope of the claims of the present invention. .

Claims (5)

1. a regenerative regenerative supercritical carbon dioxide circulation system switched by a valve, is characterized in that: comprising, a heating assembly (100), comprising a storage tank (101), a pump (102) connected to the storage tank (101), and a heat source (103) connected to the pump (102); a power generation assembly (200) connected to the pump (102), comprising a turbine (201) and a generator (202) connected to the turbine (201); A heat storage assembly (300), connected to the turbine (201), comprising a heat storage element (301), a cooler (302) connected to the heat storage element (301), and the cooler (302) connected compressor (303); The heating assembly (100), the power generation assembly (200) and the heat storage assembly (300) are connected by pipelines; a first regulating valve (101a) and a first three A through valve (101b), the first three-way valve (101b) is connected to the first regulating valve (101a), the heat source (103) and the turbine (201); the heat storage element (301) includes a first regenerator (301a) and a second regenerator (301b), a second three-way valve (301c) is connected between the first regenerator (301a), the second regenerator (301b) and the turbine (201) ; The first regenerator (301a) and the second regenerator (301b) are respectively provided with a filling port (301a-1), a thermal storage inlet regulating valve (301a-2), and a thermal storage outlet regulating valve (301a-1). 3), the exothermic inlet regulating valve (301a-4) and the exothermic outlet regulating valve (301a-5), the first regenerator (301a) and the second regenerator (301b) are also filled with fillers (301a-6); the heat storage inlet regulating valves (301a-2) of the first regenerator (301a) and the second regenerator (301b) are connected to the second three-way valve (301c), which stores heat The outlet regulating valve (301a-3) is connected with the cooler (302) through the third three-way valve (301d), and the heat releasing inlet regulating valve (301a-4) and the compressor (303) are connected through the fourth three-way valve (301e) ) is connected, and the heat release outlet regulating valve (301a-5) is connected with the heat source (103) through the fifth three-way valve (301f); The work flow is as follows: the supercritical carbon dioxide working medium is heated by the heat source (103), enters the turbine (201) to perform work, and drives the generator (202) to generate electricity. 201) is discharged, and heat is stored through the second three-way valve (301c) and the heat storage inlet regulating valve (301a-2) of the second regenerator (301b), and the heat of the supercritical carbon dioxide working medium is stored by the first The storage temperature of the secondary regenerator (301b) decreases, the cooled supercritical carbon dioxide working fluid flows into the cooler (302) through the heat storage outlet regulating valve (301a-3) and the temperature continues to decrease, and the cooled supercritical carbon dioxide enters the The compressor (303) is pressurized, and the supercritical carbon dioxide working medium after the pressure rise passes through the fourth three-way valve (301d) and the heat release inlet regulating valve (301a-4) of the first regenerator (301a). ) flows into the first regenerator (301a), the supercritical carbon dioxide working medium absorbs the heat stored before the first regenerator (301a), and the temperature increases, and the heated supercritical carbon dioxide working medium is reheated from the first regenerator (301a). The heat release outlet regulating valve (301a-5) of the generator (301a) is discharged, and the next cycle continues through the fifth three-way valve (301f) and the heat source (103); The heat storage time of the regenerator (301a) and the second regenerator (301b) are switched regularly. When one of the regenerative regenerators is full of heat, the valve on the heat storage side is closed, and the regenerative regenerator is closed. The other regenerative regenerator opens the valve on the heat storage side to store heat, and closes the valve on the heat release side; the cycle is switched in this way. 2 . The valve-switched regenerative regenerative supercritical carbon dioxide cycle system according to claim 1 , wherein the compressor ( 303 ) is further connected with an electric motor ( 303 a ). 3 . 3 . The valve-switched regenerative regenerative supercritical carbon dioxide cycle system according to claim 2 , wherein the heat source ( 103 ) adopts a heat source with a temperature of 400-750° C. such as solar energy, nuclear reactor, industrial waste heat, etc. 4 . 4. The valve-switched regenerative regenerative supercritical carbon dioxide cycle system according to claim 3, wherein the filling material (301a-6) has a filling degree ranging from 0.3 to 0.5, and it can be selected Corundum balls, cast ceramics and alloys. 5. The valve-switched regenerative regenerative supercritical carbon dioxide cycle system according to claim 4, wherein the first regenerator (301a) and the second regenerator (301b) are integrally formed, Made of stainless steel.

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