阅读说明：本技术 一种超临界co2混合工质换热实验系统 (Supercritical CO2Mixed working medium heat exchange experimental system ) 是由 舒歌群 张洪飞 田华 石凌峰 王轩 陈天宇 李聿容 于 2021-09-18 设计创作，主要内容包括：本发明公开了一种超临界CO-(2)混合工质换热实验系统,包括有主换热回路和均相混合回路,在均相混合回路中设有均相混流罐,可以加剧CO-(2)混合工质流体扰动,起到使CO-(2)混合工质组分混合均匀的作用；两条流体流动回路均可独立工作,独立控制,扰流回路对流体的扰动不会对主换热回路产生干扰,而且超临界CO-(2)混合工质换热实验系统由模块化自动控制系统控制,可以保证人员安全的同时,更加精确地控制系统流量、温度、压力等参数；因此本系统既可以保证工质组分浓度均匀,又可以保证换热循环过程稳定,对研究超临界CO-(2)混合工质换热机理,提高超临界CO-(2)混合工质动力循环系统的小型化与可操作性有非常重要的意义。(The invention discloses supercritical CO 2 The mixed working medium heat exchange experimental system comprises a main heat exchange loop and a homogeneous mixing loop, wherein a homogeneous mixing tank is arranged in the homogeneous mixing loop, and CO can be intensified 2 The mixed working fluid is disturbed to make CO 2 Uniformly mixing the mixed working medium components; the two fluid flow loops can work independently and are controlled independently, the disturbance of the turbulent flow loop on the fluid can not generate the disturbance on the main heat exchange loop, and the supercritical CO 2 The mixed working medium heat exchange experimental system is controlled by the modular automatic control system, so that the safety of personnel can be ensured, and parameters such as the flow, the temperature, the pressure and the like of the system can be more accurately controlled; therefore, the system can ensure the even concentration of working medium components and the stable heat exchange circulation process, and is suitable for research of supercritical CO 2 Improving supercritical CO by mixed working medium heat exchange mechanism 2 Miniaturization and application of mixed working medium power circulation systemThe operability is of great significance.)

1. Supercritical CO₂Mixing medium heat transfer experimental system, its characterized in that: comprises a main heat exchange loop and a homogeneous phase mixing loop, wherein the main heat exchange loop comprises sequentially connected CO₂The device comprises a liquid storage tank, a liquid circulation pressurizing unit, a preheating unit, a testing unit and a cooling heat exchange unit; the homogeneous phase mixing loop comprises a homogeneous phase mixed flow tank, and two ends of the homogeneous phase mixed flow tank are respectively connected with the CO₂A liquid storage tank and a liquid circulation pressurizing unit.

2. A supercritical CO according to claim 1₂Mixing medium heat transfer experimental system, its characterized in that: in the CO₂A differential pressure liquid level meter is arranged on the liquid storage tank, and CO is₂The thermal resistor and CO are arranged in the liquid storage tank₂The liquid inlet of the liquid storage tank is connected with a water cooler, the water cooler and CO₂An electric regulating valve I is arranged between the liquid storage tanks.

3. A supercritical CO according to claim 2₂Mixing medium heat transfer experimental system, its characterized in that: the liquid circulation pressurizing unit comprises a circulation pressurizing pump, a mass flowmeter, a liquid inlet end of the circulation pressurizing pump and CO₂The liquid outlet end of the liquid storage tank is connected with the liquid inlet end of the circulating booster pump and is connected with CO₂A filter is arranged between the liquid outlet ends of the liquid storage tanks, the liquid outlet end of the circulating booster pump is connected with the liquid inlet end of the mass flow meter, and a flow stabilizer and a safety valve are arranged between the liquid outlet end of the circulating booster pump and the liquid inlet end of the mass flow meter.

4. A supercritical CO according to claim 3₂Mixing medium heat transfer experimental system, its characterized in that: and the safety valve outlet pipeline and the drain port pipeline are provided with heat tracing belts.

5. A supercritical CO according to claim 3₂Mixing medium heat transfer experimental system, its characterized in that: the preheating unit is a preheater, the preheater is connected with the liquid outlet end of the mass flow meter, a bypass electric regulating valve is installed between the preheater and the liquid outlet end of the mass flow meter, the preheater directly heats the metal coil pipe through a direct current power supply, a temperature TIC control loop is adopted for outlet temperature control or heating current is manually set for fixed power heating, and an insulating joint is arranged at the inlet end of the preheater.

6. A supercritical CO according to claim 5₂Mixing medium heat transfer experimental system, its characterized in that: the test unit is oneThe section runner, the runner import is connected with preheater liquid outlet end, is equipped with import and export thermodetector and import and export differential pressure detection mouth respectively at the import and export of runner, sets up the heating copper billet at the bottom of runner, has 30 heating rods to heat, sets up 11 thermocouple wall temperature check points at the runner bottom, installs electrical control valve two at the liquid outlet of runner.

7. A supercritical CO according to claim 6₂Mixing medium heat transfer experimental system, its characterized in that: the cooling heat exchange unit is a condenser, and two ends of the condenser are respectively connected with the liquid outlet end of the test unit and the CO₂The liquid inlet end of the liquid storage tank is connected.

8. A supercritical CO according to claim 7₂Mixing medium heat transfer experimental system, its characterized in that: the water chiller is provided with a liquid storage tank cold water branch, a circulating booster pump cold water branch and a differential pressure liquid level meter and a cold water accompanying branch.

9. A supercritical CO according to claim 3₂Mixing medium heat transfer experimental system, its characterized in that: the liquid inlet end of the homogeneous mixed flow tank is connected with the outlet end of the safety valve, and the liquid inlet end of the homogeneous mixed flow tank is also provided with an electric flow control valve.

10. A supercritical CO according to claim 9₂Mixing medium heat transfer experimental system, its characterized in that: the homogeneous mixed flow tank comprises a cylinder body, wherein a first threaded connector is connected to the inlet end of the cylinder body through a connecting nut, a pipe cap is connected to the outlet end of the cylinder body through threads, an outlet is formed in the lower end of the pipe cap, a second threaded connector is welded to the outlet of the pipe cap, turbulent flow fillers are filled in the cylinder body and are separated in the cylinder body through a pore plate, a U-shaped bolt is sleeved on the outer side of the cylinder body, a fixing plate is connected between two end portions of the U-shaped bolt and fixed through a nut, a rib plate is fixed on the fixing plate, and a lug plate is fixed to the other end of the rib plate.

Technical Field

The invention relates to the technical field of supercritical mixed working media, in particular to supercritical CO₂Mixed working medium heat transfer experimental system.

Background

Supercritical CO₂The mixed working medium power cycle can improve the operability and the cycle heat efficiency of the waste heat recovery system, is a future development trend, and has good development prospect. Due to supercritical CO₂In a mixed working medium, CO₂The physical property difference with other working media is huge, the critical point is far away, the working media are not easy to be fully mixed, and the concentration of the circulated components cannot be ensured; in addition, due to the coupling of the parameters such as component concentration, flow rate, pressure, temperature, etc., the instability or change of one parameter can affect other parameters and the overall state. The existing heat exchange experiment table does not adopt a mixed working medium homogeneous mixing technology and a modularized automatic control design, so that the working medium is not uniformly mixed, the operation difficulty is high, and the steady-state condition is difficult to achieve. Therefore, there is no reference to supercritical CO₂Measurement experiment system of mixed working medium heat transfer characteristic. For developing the supercritical mixed working medium technology, the invention of the supercritical CO which can ensure the uniform concentration of working medium components and the stable heat exchange circulation process is urgently needed₂Mixed working medium heat exchange experimental system and method for researching supercritical CO₂Improving supercritical CO by mixed working medium heat exchange mechanism₂The miniaturization and operability of the mixed working medium power circulating system have very important significance.

Disclosure of Invention

The invention aims to make up the defects of the prior art and provides supercritical CO₂A mixed working medium heat exchange experimental system aims to solve the problems that in the prior art, working media are not mixed uniformly, the operation difficulty is high, and the steady-state condition is difficult to achieve.

The invention is realized by the following technical scheme:

supercritical CO₂The mixed working medium heat exchange experimental system comprises a main heat exchange loop and a homogeneous phase mixing loop, wherein the main heat exchange loop comprises sequentially connected CO₂The device comprises a liquid storage tank, a liquid circulation pressurizing unit, a preheating unit, a testing unit and a cooling heat exchange unit; the homogeneous phase mixing loop comprises a homogeneous phase mixed flow tank, and two ends of the homogeneous phase mixed flow tank are respectively connected with the CO₂A liquid storage tank and a liquid circulation pressurizing unit.

In the CO₂A differential pressure liquid level meter is arranged on the liquid storage tank, and CO is₂The thermal resistor and CO are arranged in the liquid storage tank₂The liquid inlet of the liquid storage tank is connected with a water cooler, the water cooler and CO₂An electric regulating valve I is arranged between the liquid storage tanks.

The liquid circulation pressurizing unit comprises a circulation pressurizing pump, a mass flowmeter, a liquid inlet end of the circulation pressurizing pump and CO₂The liquid outlet end of the liquid storage tank is connected with the liquid inlet end of the circulating booster pump and is connected with CO₂A filter is arranged between the liquid outlet ends of the liquid storage tanks, the liquid outlet end of the circulating booster pump is connected with the liquid inlet end of the mass flow meter, and a flow stabilizer and a safety valve are arranged between the liquid outlet end of the circulating booster pump and the liquid inlet end of the mass flow meter.

And the safety valve outlet pipeline and the drain port pipeline are provided with heat tracing belts.

The preheating unit is a preheater, the preheater is connected with the liquid outlet end of the mass flow meter, a bypass electric regulating valve is installed between the preheater and the liquid outlet end of the mass flow meter, the preheater ensures that a medium reaches a preset temperature, the metal coil is directly heated through a direct-current power supply, a temperature TIC control loop is adopted for outlet temperature control, and heating current can be manually set for heating with fixed power. So as to ensure that the preheating temperature reaches the preset requirement when entering the test heating section, and an insulating joint is arranged at the inlet. Prevent to form the potential difference after the circular telegram and cause instrument damage and local overcurrent heating.

The test unit is a section of flow passage, an inlet of the flow passage is connected with a liquid outlet end of the preheater, an inlet and an outlet temperature detector and an inlet and outlet differential pressure detection port are respectively arranged at an inlet and an outlet of the flow passage, a heating copper block is arranged at the bottom of the flow passage, 30 heating rods are used for heating, 11 thermocouple wall temperature detection points are arranged at the bottom of the flow passage, and an electric regulating valve II is arranged at a liquid outlet of the flow passage.

The cooling heat exchange unit is a condenser, and two ends of the condenser are respectively connected with the liquid outlet end of the test unit and the CO₂The liquid inlet end of the liquid storage tank is connected.

The water chiller is provided with a liquid storage tank cold water branch, a circulating booster pump cold water branch and a differential pressure liquid level meter and a cold water accompanying branch.

The liquid inlet end of the homogeneous mixed flow tank is connected with the outlet end of the safety valve, and the liquid inlet end of the homogeneous mixed flow tank is also provided with an electric flow control valve.

The homogeneous mixed flow tank comprises a cylinder body, wherein a first threaded connector is connected to the inlet end of the cylinder body through a connecting nut, a pipe cap is connected to the outlet end of the cylinder body through threads, an outlet is formed in the lower end of the pipe cap, a second threaded connector is welded to the outlet of the pipe cap, turbulent flow fillers are filled in the cylinder body and are separated in the cylinder body through a pore plate, a U-shaped bolt is sleeved on the outer side of the cylinder body, a fixing plate is connected between two end portions of the U-shaped bolt and fixed through a nut, a rib plate is fixed on the fixing plate, and a lug plate is fixed to the other end of the rib plate.

The pressure element cylinder body material of homogeneous phase mixed flow jar be the stainless steel, design pressure is 10MPa, operating pressure 7MPa, the vortex filler is porous medium materials such as metal foam, vortex structure for fluid disturbance, still is equipped with O type sealing washer between the import of cylinder body and threaded joint one, O type sealing washer material is corrosion-resistant swelling material, like polytetrafluoroethylene, perfluororubber.

CO₂The mixed working medium homogeneous mixed flow tank is positioned in a system turbulent flow loop and used for CO₂The mixed working medium is disturbed to realize CO₂The component uniformity degree of the mixed working medium improves the experimental precision of the heat exchange process of the test section. CO 2₂The working principle of the homogeneous mixed flow tank of the mixed working medium is that the turbulent flow effect of the porous medium to the fluid causes the mixed working medium to be in CO₂The mixed working medium is fully mixed in the homogeneous mixed flow tank.

Raw gas (CO) from steel cylinder weighed by electronic scale₂) Through a filter, CO₂Compressor or bypass to CO₂A liquid storage tank for carrying out CO treatment by using chilled water conveyed by a water cooler₂And (5) liquefying and cooling. Liquefied CO₂Temperature regulation of cold liquid by electric regulating valve to maintain constant in-tank CO₂The liquefaction temperature. Liquefied CO₂Liquid level measurement is carried out through the differential pressure level gauge of installing on the liquid storage pot to liquid, carries out temperature teletransmission control through the thermal resistance of installing in the liquid storage pot and detects. Liquefied CO₂By CO₂Increasing the delivery of the pump to the post-system. The outlet of the booster pump is provided with a mass flowmeter and a bypass electric regulating valve for accurately metering and conveying CO to a rear system₂The quality of (c).

CO in the liquid storage tank₂The liquid is circularly pressurized through a circulating booster pump, a pump outlet is provided with a flow stabilizer, a liquid mass flowmeter and a bypass electric regulating valve so as to ensure the stable conveying of the liquid flow. The circulating booster pump is provided with frequency conversion control, and the bypass regulating valve and the mass flowmeter form automatic loop control to ensure the stable circulating flow of the system. The inlet of the pump is provided with a filter for filtering impurities, and the outlet is provided with a safety valve for preventing the pump and parts thereof from being damaged by conveying overpressure. The safety valve outlet pipeline and the exhaust port pipeline are both provided with heat tracing bands, and CO is arranged on the pipeline₂CO mode in overpressure discharge or exhaust emission₂The gasification absorbs heat to freeze and damage the pipeline pipe fitting.

The invention has the advantages that: supercritical CO of the invention₂The mixed working medium heat exchange experimental system comprises two fluid flow loops, wherein one fluid flow loop is a main heat exchange loop, the other fluid flow loop is a homogeneous mixing loop, and a CO is automatically designed in the homogeneous mixing loop₂The mixed working medium homogeneous mixed flow tank can intensify CO₂The mixed working fluid is disturbed to make CO₂Uniformly mixing the mixed working medium components; the two fluid flow loops can work independently and are controlled independently, the disturbance of the turbulent flow loop on the fluid can not generate the disturbance on the main heat exchange loop, and the supercritical CO₂The mixed working medium heat exchange experimental system is controlled by the modularized automatic control system, so that a person can be guaranteedThe system flow, temperature, pressure and other parameters are controlled more accurately while personnel are safe; therefore, the system can ensure the even concentration of working medium components and the stable heat exchange circulation process, and is suitable for research of supercritical CO₂Improving supercritical CO by mixed working medium heat exchange mechanism₂The miniaturization and operability of the mixed working medium power circulating system have very important significance.

Drawings

FIG. 1 is a supercritical CO of the present invention₂A circulation system diagram of the mixed working medium heat exchange experimental system;

FIG. 2 shows CO in the present invention₂A mixed working medium homogeneous mixed flow tank is cut into sections;

FIG. 3 is CO of the present invention₂And (4) a top view of the mixed working medium homogeneous-phase mixed flow tank.

Detailed Description

As shown in FIG. 1, a supercritical CO₂The mixed working medium heat exchange experimental system comprises a main heat exchange loop and a homogeneous phase mixing loop, wherein the main heat exchange loop comprises sequentially connected CO₂The device comprises a liquid storage tank 1, a liquid circulation pressurizing unit, a preheating unit, a testing unit 2 and a cooling heat exchange unit; the homogeneous phase mixing loop comprises a homogeneous phase mixed flow tank 3, and two ends of the homogeneous phase mixed flow tank 3 are respectively connected with the CO₂A liquid storage tank 1 and a liquid circulation pressurization unit.

In the CO₂A differential pressure liquid level meter is arranged on the liquid storage tank 1 and is connected with CO₂The thermal resistor and CO are arranged in the liquid storage tank₂The liquid inlet of the liquid storage tank 1 is connected with a water cooler 4, the water cooler 4 and CO₂An electric regulating valve I is arranged between the liquid storage tanks 1.

The liquid circulation pressurizing unit comprises a circulation pressurizing pump 5 and a mass flowmeter 6, wherein the liquid inlet end of the circulation pressurizing pump 5 and CO₂The liquid outlet end of the liquid storage tank 1 is connected with the liquid inlet end of the circulating booster pump 5 and CO₂A filter 7 is arranged between the liquid outlet ends of the liquid storage tank 1, the liquid outlet end of the circulating booster pump 5 is connected with the liquid inlet end of the mass flow meter 6, and a flow stabilizer 8 and a safety valve 9 are arranged between the liquid outlet end of the circulating booster pump 5 and the liquid inlet end of the mass flow meter 6.

And the outlet pipeline of the safety valve 9 and the drain port pipeline are both provided with heat tracing belts.

The preheating unit be preheater 10, preheater 10 is connected with mass flow meter 6's play liquid end, installs bypass electrical control valve 11 between preheater 10 and mass flow meter 6's the play liquid end, preheater 10 ensure that the medium reaches preset temperature, directly heat the metal coil pipe through DC power supply, adopt temperature TIC control circuit to carry out export temperature control, also can manually set up heating current and carry out the heating of fixed power. So as to ensure that the preheating temperature reaches the preset requirement when entering the test heating section, and an insulating joint is arranged at the inlet. Prevent to form the potential difference after the circular telegram and cause instrument damage and local overcurrent heating.

The test unit 2 is a section of flow channel 12, the inlet of the flow channel 12 is connected with the liquid outlet end of the preheater 11, the inlet and the outlet of the flow channel 12 are respectively provided with an inlet and outlet temperature detector and an inlet and outlet differential pressure detection port, the bottom of the flow channel is provided with a heating copper block, 30 heating rods are used for heating, the bottom of the flow channel is provided with 11 thermocouple wall temperature detection points, and the liquid outlet of the flow channel is provided with an electric control valve II 13.

The cooling heat exchange unit is a condenser 14, and two ends of the condenser 14 are respectively connected with the liquid outlet end of the test unit and the CO₂The liquid inlet end of the liquid storage tank 1 is connected.

The water chiller 4 is provided with a liquid storage tank cold water branch, a circulating booster pump cold water branch and a differential pressure liquid level meter and a cold water branch.

The liquid inlet end of the homogeneous mixed flow tank 3 is connected with the outlet end of the safety valve 9, and the liquid inlet end of the homogeneous mixed flow tank 3 is also provided with an electric flow control valve 15.

As shown in fig. 2 and 3, the homogeneous mixing tank 3 includes a cylinder 16, a first threaded connector 18 is connected to an inlet end of the cylinder 16 through a connecting nut 17, a pipe cap 19 is connected to an outlet end of the cylinder 16 through a thread, a second threaded connector 20 is welded to a lower end of the pipe cap 19, a turbulent filler 21 is filled in the cylinder 16, the turbulent filler 21 is blocked in the cylinder 16 through a hole plate 22, a U-shaped bolt 23 is sleeved outside the cylinder 16, a fixing plate 24 is connected between two ends of the U-shaped bolt 23 and fixed through a nut 25, a rib plate 26 is fixed on the fixing plate 24, and an ear plate 27 is fixed to the other end of the rib plate 26. The U-shaped bolt 23, the fixing plate 24, the rib plate 26 and the lug plate 27 are used for fixing the homogeneous mixed flow tank 3.

The pressure element cylinder body material of homogeneous phase mixed flow jar 3 be stainless steel, design pressure is 10MPa, operating pressure 7MPa, the vortex filler is porous medium materials such as metal foam, vortex structure for fluid disturbance, still is equipped with O type sealing washer between the import of cylinder 16 and nipple 18, O type sealing washer material is corrosion-resistant swelling material, like polytetrafluoroethylene, perfluor rubber.

Before the experiment begins, the system is provided with a special mixed working medium proportioning system, and the accurate proportioning of the components of the mixed working medium is realized by using a high-precision electronic balance and a delivery pump (the specific complexity is not the key point of the description of the patent) due to CO₂Different components of the mixed working medium can generate layering and component migration phenomena, namely, the components are unevenly distributed, the accuracy of the experiment is seriously influenced, and a turbulent flow loop needs to be opened before the experiment begins to carry out on CO₂The mixed working medium is subjected to turbulent flow treatment, and a turbulent flow loop is opened to carry out turbulent flow treatment in the experimental process, so that CO is subjected to turbulent flow treatment₂The components of the mixed working medium are uniformly distributed.

CO₂CO in the liquid storage tank 1₂The mixed working medium liquid is circularly pressurized through a circulating booster pump 5, and a flow stabilizer 8, a liquid mass flow meter 6 and a bypass electric regulating valve 11 are arranged at the outlet of the circulating booster pump 5 to ensure the stable transmission of the liquid flow. The circulating booster pump 5 is provided with frequency conversion control, and the bypass regulating valve 11 and the mass flowmeter 6 form automatic loop control to ensure the stable circulating flow of the system. The inlet of the pump is provided with a filter 7 for filtering impurities, and the outlet is provided with a safety valve 9 for preventing the pump and parts thereof from being damaged by delivery overpressure. The outlet pipeline and the exhaust port pipeline of the safety valve 9 are both provided with heat tracing bands, and CO is arranged on the pipeline₂CO mode in overpressure discharge or exhaust emission₂The gasification absorbs heat to freeze and damage the pipeline pipe fitting. Direct current heating (direct current) is arranged in front of the test section for controlling CO in front of the test section₂The temperature of the mixed working medium is stable and reaches the set temperature. An electric regulating valve II is arranged behind the test section and used forRegulating CO in the test section₂The working pressure of the mixed working medium reaches a set value, the system finishes flow temperature pressure regulation till the working pressure of the mixed working medium reaches the set value, the temperature pressure flow in the testing section reaches the set value, and CO is heated in the testing section₂The mixed working medium enters a cooling unit and is cooled back to CO₂A liquid storage tank. All the controls adopt modularized automatic control, and can accurately control each experimental parameter while ensuring the safety of personnel. The two fluid flow circuits can work independently and are controlled independently. The disturbance of the turbulent flow loop on the fluid does not interfere with the main heat exchange loop. A CO is designed in a homogeneous phase mixing loop₂Mixing working medium homogeneous-phase mixed flow tank (as shown in figure 2) to intensify CO₂The mixed working fluid is disturbed to make CO₂The mixed working medium components are uniformly mixed. CO 2₂The tank body of the mixed working medium homogeneous-phase mixed-flow tank is made of stainless steel, and the design pressure is 10 MPa. The fluid flows in from N1, and N2 flows out, and in 4 barrel, fill up porous medium and be used for the vortex of mixed working medium. The porous media is blocked in the canister by a 3-well plate. The well plate structure (shown in fig. 3) is a multi-well plate.

The embodiments of the present invention are described only for the preferred embodiments of the present invention, and not for the limitation of the concept and scope of the present invention, and various modifications and improvements made to the technical solution of the present invention by those skilled in the art without departing from the design concept of the present invention shall fall into the protection scope of the present invention, and the technical content of the present invention which is claimed is fully set forth in the claims.