CN113217222A - Stirling engine system for coupling liquid metal cooling reactor - Google Patents

Abstract

Translated fromChinese

本发明涉及一种用于耦合液金属冷却反应堆的斯特林发动机系统，属于核反应堆动力转换技术领域，包括液金属‑工质换热系统、斯特林循环系统、传动系统；液金属‑工质换热系统包括弯管式换热器，换热管束为环形排列，中央设有液金属入口管和液金属出口管，液金属入口管管壁上设有入口窗，液金属出口管管壁上设有出口窗；气缸外壁与弯管式换热器的外壳限制形成弯管式换热器的壳程空间，液金属在壳程空间内流动，工质在换热管束内流动；活塞将气缸内空间分割为热腔室和冷腔室，热腔室与弯管式换热器的热腔接口相连；弯管式换热器的冷腔接口与回热器相连。本发明提供的系统能够以液金属反应堆产生的热量作为热源进行热电转换，并保证较高的转换效率。

The invention relates to a Stirling engine system for coupling a liquid metal cooling reactor, belonging to the technical field of nuclear reactor power conversion, comprising a liquid metal-working fluid heat exchange system, a Stirling cycle system and a transmission system; a liquid metal-working fluid The heat exchange system includes an elbow-type heat exchanger. The heat exchange tube bundles are arranged in a ring shape. The liquid metal inlet tube and the liquid metal outlet tube are arranged in the center. The inlet window is arranged on the wall of the liquid metal inlet tube and the wall of the liquid metal outlet tube is arranged There is an outlet window; the outer wall of the cylinder and the shell of the elbow heat exchanger are restricted to form the shell side space of the elbow type heat exchanger, the liquid metal flows in the shell side space, and the working medium flows in the heat exchange tube bundle; The inner space is divided into a hot chamber and a cold chamber, and the hot chamber is connected with the hot chamber interface of the elbow heat exchanger; the cold chamber interface of the elbow heat exchanger is connected with the regenerator. The system provided by the invention can use the heat generated by the liquid metal reactor as a heat source to perform thermoelectric conversion, and ensure high conversion efficiency.

Description

Stirling engine system for coupling liquid metal cooling reactor

Technical Field

The invention belongs to the technical field of nuclear reactor power conversion, and particularly relates to a Stirling engine system for coupling a liquid metal cooled reactor.

Background

The conventional power conversion device coupled with the nuclear reactor is a steam turbine, the steam turbine unit has multiple advantages of mature technical development, high conversion efficiency, rich engineering application experience and the like, but for the coupling of the reactor taking liquid metal, particularly alkali metal, as a coolant, the chemical property of the metal is active, and the risk of reaction with water exists under the high-temperature condition, so that the risk exists in the coupling of the steam turbine and the liquid metal reactor, and the structure of a matching device of the steam turbine unit is complex, so that the miniaturization, modularization and movability of a nuclear reactor power generation device are not facilitated.

The stirling engine technology has developed relatively mature, is simple in structure, and has inherent characteristics of being capable of being used for various heat sources, so that the stirling engine is more suitable for being coupled with a liquid metal reactor. The conventional Stirling engine mostly adopts heat energy generated by combustion of hydrocarbon fuel as a heat source to drive working media to do work, the maximum temperature of flame during combustion of the fuel can reach 2000 ℃, the temperature difference of a cold end and a hot end of a generator is mostly about 700 ℃, a liquid metal reactor is used as the heat source, and the temperature difference of the cold end and the hot end is only 300 ℃, so that the Stirling engine needs to be modified to adapt to the heat source with a heat exchange form with lower temperature difference.

Disclosure of Invention

In view of the defects in the prior art, the invention aims to provide a stirling engine system for coupling a liquid metal cooled reactor, so that the stirling engine can perform thermoelectric conversion by using heat generated by the liquid metal reactor as a heat source and ensure higher energy conversion efficiency.

In order to achieve the above purposes, the invention adopts the technical scheme that: a Stirling engine system for coupling a liquid metal cooled reactor comprises a liquid metal-working medium heat exchange system, a Stirling circulating system, a transmission system and an output shaft;

the liquid metal-working medium heat exchange system comprises a bent pipe type heat exchanger, heat exchange pipe bundles of the bent pipe type heat exchanger are arranged in an annular mode, a liquid metal inlet pipe and a liquid metal outlet pipe are arranged in the center of the bent pipe type heat exchanger, a liquid metal inlet window is arranged on the pipe wall of the liquid metal inlet pipe, and a liquid metal outlet window is arranged on the pipe wall of the liquid metal outlet pipe; the outer wall of the cylinder and the shell of the bent-tube heat exchanger limit to form a shell side space of the bent-tube heat exchanger, liquid metal flows in the shell side space, and working media flow in the heat exchange tube bundle;

the Stirling cycle system comprises cylinders, pistons reciprocating inside the cylinders, a heat regenerator and a cooler arranged outside the cylinders, and a cold cavity connecting pipe for connecting two adjacent cylinders, wherein the pistons divide the space in the cylinders into a hot cavity and a bottom cold cavity, and the hot cavity is connected with a hot cavity interface of the bent pipe type heat exchanger; one end of the cold cavity connecting pipe is connected with the cooling cavity of the cooler, the other end of the cold cavity connecting pipe is connected with the bottom cold cavity of the adjacent cylinder, and the cooling cavity of the cooler, the cold cavity connecting pipe and the bottom cold cavity of the adjacent cylinder form a cold cavity together; a cold cavity interface of the bent pipe type heat exchanger is connected with the heat regenerator and is communicated with the cold cavity chamber through the heat regenerator and the cooler;

and a connecting rod is arranged on the bottom surface of the piston and is connected with the transmission system through the connecting rod.

Further, a stirling engine system for coupling a liquid metal cooled reactor as described above, said liquid metal being liquid sodium, a sodium potassium alloy or a lead bismuth alloy.

Further, the Stirling engine system for the coupling liquid metal cooled reactor is characterized in that the working medium is helium, hydrogen, nitrogen or air.

Further, in the stirling engine system for a coupling liquid metal cooled reactor as described above, the bundle of heat exchange tubes of the bent tube heat exchanger is one or more layers.

Further, in the stirling engine system for coupling a liquid metal cooled reactor as described above, the top surface of the piston is hemispherical.

Further, the Stirling engine system for the coupling liquid metal cooling reactor is a multi-cylinder Stirling engine system, the multiple cylinders are multiples of four cylinders, and each cylinder is provided with a set of liquid metal-working medium heat exchange system.

Further, a stirling engine system for coupling a liquid metal cooled reactor as described above, said cooler comprising a cooling water inlet and outlet connection, a cooling water channel and a cooling device.

Further, the Stirling engine system for the coupling liquid metal cooled reactor uses the cooling water of the cooler which is seawater or industrial circulating cooling water.

Further, the stirling engine system for coupling the liquid metal cooled reactor as described above further comprises a flow distributor for uniformly distributing the liquid metal to each liquid metal-working medium heat exchange system.

The stirling engine system for coupling a liquid metal cooled reactor provided by the present invention has the following advantages:

the Stirling engine system completes the transformation of a conventional Stirling engine external combustion system, adopts the multilayer bent pipe type heat exchanger, solves the problem of high-efficiency heat exchange between liquid metal and helium, realizes that the Stirling engine drives the generator to generate electricity by using heat led out from the reactor as a heat source, provides an equipment foundation for the Stirling engine to be coupled with the liquid metal reactor, and provides a practical and feasible technical route for realizing the miniaturization, modularization and mobilization of the liquid metal reactor.

Drawings

FIG. 1 is a schematic block diagram of a Stirling engine system for coupling a liquid metal cooled reactor according to an embodiment of the present invention;

FIG. 2 is a cross-sectional view of the liquid metal-working fluid heat exchange system of the embodiment of FIG. 1;

FIG. 3 is a top view of the liquid metal to working fluid heat exchange system of the embodiment of FIG. 1;

wherein: 1-liquid metal-working medium heat exchange system; 2-a stirling cycle system; 3-a transmission system; 4-an output shaft; 11-liquid metal inlet pipe; 12-liquid metal outlet pipe; 13-liquidmetal access window 13; 14-liquid metal outlet window; 15-a bent tube heat exchanger; 16-a thermal cavity interface; 17-cold chamber interface; 21-cylinder; 22-a piston; 23-a heat regenerator; 24-a cooler; 25-cold chamber connecting pipe; 26-a thermal chamber; 27-a cold chamber; 31-a connecting rod; 32-crankshaft.

Detailed Description

The invention is further described with reference to the following figures and detailed description.

As shown in fig. 1-3, the present embodiment provides a stirling engine system for coupling a liquid metal cooled reactor, the system comprising four sets of liquid metal-working medium heat exchange systems 1, four sets ofstirling cycle systems 2, four sets of transmission systems 3 and anoutput shaft 4;

the liquid metal-working medium heat exchange system 1 comprises a bent pipetype heat exchanger 15, wherein heat exchange pipe bundles of the bent pipetype heat exchanger 15 are arranged in an annular mode, a liquidmetal inlet pipe 11 and a liquidmetal outlet pipe 12 are arranged in the center of the bent pipe type heat exchanger, a liquidmetal inlet window 13 is formed in the pipe wall of the liquidmetal inlet pipe 11, and a liquidmetal outlet window 14 is formed in the pipe wall of the liquidmetal outlet pipe 12; the outer wall of the cylinder and the shell of the bent-tube heat exchanger 15 limit to form a shell side space of the bent-tube heat exchanger 15, liquid metal flows in the shell side space, and working medium flows in the heat exchange tube bundle.

Wherein the liquid metal is liquid sodium, sodium-potassium alloy, lead-bismuth alloy or other liquid metals for cooling the reactor; the working medium is helium, hydrogen, nitrogen or air.

Because the liquid metal reactor cold and hot end difference in temperature is lower, belong to the low temperature heat source to stirling, need great heat transfer area to guarantee sufficient heat transfer volume, consequently set up the elbow type and add the heat exchanger, the quantity of heat exchange tube is the one deck in this embodiment, and liquid metal is liquid sodium, and the working medium is helium. Helium working medium flows in the heat exchange tube bundle, liquid sodium flows in from the liquidmetal inlet pipe 11 through the liquidmetal inlet window 13, and flows for half a circle along the heat exchange tube bundle and then flows out from the liquidmetal outlet window 14 through the liquidmetal outlet pipe 12. The bent pipe type heat exchanger has the advantages that the liquid metal side pressure is low, a very pressure-resistant structure is not required to be designed, the bent pipe can also spontaneously solve the problem of thermal stress caused by thermal expansion of the pipe bundle, meanwhile, the useless volume of the heater can also be effectively controlled, and the whole efficiency of the Stirling engine is guaranteed to be controlled. According to the difference of the liquid metal heat source temperature and the output power, the number of the heat exchange tubes can be determined through calculation, and the heat exchange tube bundle is made of stainless steel or special metal materials under the common condition.

In other embodiments of the invention, multiple layers of heat exchange tubes can be arranged according to the heat exchange quantity requirement. The design and arrangement of the heating pipe are relatively more complicated because the central circular area and the peripheral annular area of the heater must be connected in a one-to-one manner in the multi-layer bent pipe structure, and firstly, the number of the pipe bundles with equal radius at the inner ring cannot be kept consistent with that at the outer ring due to different radii.

The Stirlingcycle system 2 comprises acylinder 21, a piston 22 reciprocating inside the cylinder, aregenerator 23 and a cooler 24 arranged outside the cylinder, and a coldchamber connecting pipe 25 connecting two adjacent cylinders, wherein the piston 22 divides the space in the cylinder into a hot chamber 26 and a bottom cold chamber, and the hot chamber 26 is connected with ahot chamber connector 16 of the bent pipetype heat exchanger 15; one end of the coldcavity connecting pipe 25 is connected with the cooling cavity of the cooler 24, the other end of the cold cavity connecting pipe is connected with the bottom cold cavity of the adjacent cylinder, and the cooling cavity of the cooler 24, the coldcavity connecting pipe 25 and the bottom cold cavity of the adjacent cylinder form thecold cavity 17; thecold chamber interface 17 of the bent-tube heat exchanger 15 is connected to aregenerator 23 and communicates with thecold chamber 17 through theregenerator 23 and a cooler 24.

The bottom surface of the piston 22 is provided with a connectingrod 31, the connectingrod 31 is connected with a transmission system 3, the linear reciprocating motion of the piston 22 is converted into the rotary motion of acrankshaft 32, and the power is output through acommon output shaft 4.

The front end of the system is also provided with a flow distributor, and the liquid metal is uniformly distributed to each liquid metal-working medium heat exchange system 1 through the flow distributor.

Each Stirling engine system has at least fourcylinders 21, eachcylinder 21 is provided with a set of liquid metal-working medium heat exchange system 1, two adjacent cylinders are cold and hot chambers, the top hot chamber of the first cylinder is connected with the bottom cold chamber of the second cylinder through a heat exchange tube, a heat regenerator, a cooler and a cold chamber connecting tube, the top hot chamber of the second cylinder is connected with the bottom cold chamber of the third cylinder through a heat exchange tube, a heat regenerator, a cooler and a cold chamber connecting tube, the top hot chamber of the third cylinder is connected with the bottom cold chamber of the fourth cylinder through a heat exchange tube, a heat regenerator, a cooler and a cold chamber connecting tube, and the top hot chamber of the fourth cylinder is connected with the bottom cold chamber of the first cylinder through a heat exchange tube, a heat regenerator, a cooler and a cold chamber connecting tube.

According to different requirements on output power, the four cylinders can be used as units for splicing to form a four-cylinder Stirling engine system, an eight-cylinder Stirling engine system, a twelve-cylinder Stirling engine system or a sixteen-cylinder Stirling engine system and the like.

The working principle of the stirling engine system for coupling a liquid metal cooled reactor provided by the present embodiment is as follows:

liquid sodium heated by heat conducted out of the reactor is evenly distributed to the liquid metal-working medium heat exchange system 1 through a distributor at the front end of the Stirling engine system, the liquid sodium flows in from a liquidmetal inlet pipe 11 through a liquidmetal inlet window 13 and flows on the shell side of a bent pipetype heat exchanger 15, helium working medium is in the pipe bundle, the liquid sodium flows along the pipe bundle, and the liquid sodium flows out from a liquidmetal outlet window 14 through a liquidmetal outlet pipe 12 after the heat exchange process is completed in a flowing half circle; helium working medium flows in theheat exchange tube 15 of the heat exchanger, absorbs heat in liquid metal, pushes the piston 22 to do work through the isothermal expansion process, and the working medium after expansion and work flows into thecold chamber 27 through theheat regenerator 23 and the cooler 24 under the push of the piston 22, so that the isometric cooling process is completed; working medium entering thecold chamber 27 is isothermally compressed to the minimum volume under the action of the piston 22, and under the combined action of two adjacent pistons, the isothermal expansion is carried out through theheat regenerator 23 to push the piston 22 to do work, so that a Stirling cycle is completed.

The invention improves the heat source system of the original gas type Stirling engine, adopts the form of the bent pipe type heat exchanger, solves the problem of high-efficiency heat exchange between liquid metal and helium, can adjust the quantity and the arrangement form of the heat exchange pipes according to the difference of the temperature, the flow and the output power of the heat source, and ensures that the improved Stirling engine system can adapt to different types of heat sources. The improved Stirling engine system can realize thermoelectric conversion by taking the heat of the liquid metal reactor as a heat source, realizes the coupling of the Stirling engine and the liquid metal reactor, and lays a technical foundation for the miniaturization, modularization and movability of the liquid metal reactor.

The above-described embodiments are merely illustrative of the present invention, which may be embodied in other specific forms or in other specific forms without departing from the spirit or essential characteristics thereof. The described embodiments are, therefore, to be considered in all respects as illustrative and not restrictive. The scope of the invention should be indicated by the appended claims, and any changes that are equivalent to the intent and scope of the claims should be construed to be included therein.

Claims (9)

1. A Stirling engine system for coupling a liquid metal cooled reactor is characterized by comprising a liquid metal-working medium heat exchange system (1), a Stirling circulating system (2), a transmission system (3) and an output shaft (4);

the liquid metal-working medium heat exchange system (1) comprises a bent pipe type heat exchanger (15), heat exchange pipe bundles of the bent pipe type heat exchanger (15) are arranged in an annular mode, a liquid metal inlet pipe (11) and a liquid metal outlet pipe (12) are arranged in the center of the bent pipe type heat exchanger (15), a liquid metal inlet window (13) is formed in the pipe wall of the liquid metal inlet pipe (11), and a liquid metal outlet window (14) is formed in the pipe wall of the liquid metal outlet pipe (12); the outer wall of the cylinder and the shell of the bent tube type heat exchanger (15) limit to form a shell side space of the bent tube type heat exchanger (15), liquid metal flows in the shell side space, and working media flow in the heat exchange tube bundle;

the Stirling cycle system (2) comprises a cylinder (21), a piston (22) reciprocating inside the cylinder (21), a heat regenerator (23) and a cooler (24) which are arranged outside the cylinder, and a cold chamber connecting pipe (25) connecting two adjacent cylinders, wherein the piston (22) divides the space in the cylinder into a hot chamber (26) and a bottom cold chamber, and the hot chamber (26) is connected with a hot chamber interface (16) of the bent pipe type heat exchanger; one end of the cold cavity connecting pipe (25) is connected with the cooling cavity of the cooler (24), the other end of the cold cavity connecting pipe is connected with the bottom cold cavity of the adjacent cylinder, and the cooling cavity of the cooler (24), the cold cavity connecting pipe (25) and the bottom cold cavity of the adjacent cylinder jointly form a cold cavity (27); the cold cavity interface (17) of the bent-tube heat exchanger is connected with the heat regenerator (23) and is communicated with the cold cavity (27) through the heat regenerator (23) and the cooler (24);

and a connecting rod (31) is arranged on the bottom surface of the piston (22), and is connected with the transmission system (3) through the connecting rod (31).

2. A stirling engine system for coupling a liquid metal cooled reactor according to claim 1, wherein the liquid metal is liquid sodium, a sodium potassium alloy or a lead bismuth alloy.

3. A stirling engine system for coupling a liquid metal cooled reactor according to claim 2 wherein the working fluid is helium, hydrogen, nitrogen or air.

4. A stirling engine system for coupling a liquid metal cooled reactor according to any one of claims 1 to 3, wherein the bundle of heat exchanger tubes of the bent tube heat exchanger (15) is in one or more layers.

5. A Stirling engine system for coupling a liquid metal cooled reactor according to claim 4, wherein the top surface of the piston (22) is hemispherical.

6. A stirling engine system for coupling a liquid metal cooled reactor according to claim 1, wherein the system is a multi-cylinder stirling engine system, the multiple cylinders being a multiple of four cylinders, each cylinder being provided with a set of liquid metal-working fluid heat exchange systems (1).

7. A stirling engine system for coupling a liquid metal cooled reactor according to claim 1, wherein the cooler (24) comprises cooling water inlet and outlet connections, cooling water channels and cooling means.

8. A Stirling engine system for coupling a liquid metal cooled reactor according to claim 7, wherein the cooling water used by the cooler (24) is sea water or industrial cycle cooling water.

9. A Stirling engine system for coupling a liquid metal cooled reactor according to any one of claims 5 to 8, wherein the system further comprises a flow distributor for evenly distributing liquid metal to each liquid metal to working fluid heat exchange system (1).

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