CN111664427A

CN111664427A - Design scheme of ultra-high temperature and ultra-high pressure pore channel type heat exchanger/evaporator

Info

Publication number: CN111664427A
Application number: CN201910207138.1A
Authority: CN
Inventors: 孟想
Original assignee: Individual
Current assignee: Individual
Priority date: 2019-03-09
Filing date: 2019-03-09
Publication date: 2020-09-15

Abstract

A design scheme of an ultrahigh-temperature and ultrahigh-pressure pore channel type heat exchanger/evaporator utilizes a specially-made elliptical, semicircular or conical pore channel arranged in a heat exchange unit to exchange heat. The heat exchange among the pore passages of the small holes or the micropores mainly based on the close-contact multilayer metal heat conduction has the advantages of high heat transfer coefficient, good heat transfer efficiency, small heat transfer temperature difference of the primary side and the secondary side, safe and stable heat transfer among the pore passages under the condition of extreme high temperature or extreme high pressure, high efficiency, simplicity, safety and reliability. The accident of pipe breaking and water loss of the traditional shell-and-tube heat exchanger under the working condition of ultrahigh temperature and ultrahigh pressure can be better avoided. Compared with the shell-and-tube heat exchanger with the same heat transfer capacity, the size, the weight and the manufacturing cost of the pore channel type heat exchanger are reduced by more than one third. Under the conditions of proper heat exchange unit material selection and proper heat transfer pore channel design selection, the heat transfer is supported under the severe heat transfer condition of extreme high temperature not exceeding 1000 ℃ or extreme high pressure not exceeding 1000 kilograms. A channel type heat exchanger/evaporator belongs to the technical field of heat transfer equipment and is mainly applied to the fields of nuclear power thermal power, petrochemical industry, chemical engineering and medicine, metallurgical energy, food electronics and the like.

Description

Design scheme of ultra-high temperature and ultra-high pressure pore channel type heat exchanger/evaporator

The technical field is as follows:

the invention relates to a design scheme of a novel heat exchanger/evaporator suitable for extremely high temperature or extremely high pressure, which utilizes a special pore channel arranged in a heat exchange unit module to exchange heat and is called as a pore channel type heat exchanger/evaporator. The heat exchange between the pore passages of the small holes or the micropores mainly based on the heat conduction of the heat transfer material has the characteristics of high heat transfer coefficient, small heat transfer temperature difference, high efficiency, simplicity, safety and reliability, can safely and stably transfer heat between the pore passages under the condition of extreme high temperature or extreme high pressure, belongs to the technical field of heat transfer equipment, and mainly applies to nuclear thermoelectricity, petrochemical industry, chemical and medical industry, metallurgical energy, food electronics and the like.

(II) background technology:

a nuclear power steam generator (steam generator) is a heat exchange device for generating steam required by a steam turbine, in a nuclear reactor, heat generated by nuclear fission is taken out by a coolant, and is transferred to a two-loop working medium through the steam generator, so that the steam generator generates steam with a certain temperature, a certain pressure and a certain dryness. The steam enters a steam turbine to do work and is converted into electric energy or mechanical energy. In this energy conversion process, the steam generator is a primary and a secondary loop device, and is therefore called a primary and secondary loop hub. The nuclear power steam generator is also one of the most critical main devices of the nuclear power station, is connected with a reactor pressure vessel, not only directly influences the power and the efficiency of a power station, but also plays a role in blocking radioactive heat-carrying agents when heat exchange is carried out, and is of great importance to the safety of the nuclear power station. Therefore, steam generators perform quality requirements of safety class one, class I anti-seismic class one, class one specification class and class one quality assurance class one, with high technical content of materials and manufacturing being the most important for contemporary manufacturing.

The nuclear power steam generator is used as a primary loop device of a nuclear island, and has the main functions of: transferring the heat of the coolant of the primary loop to feed water of the secondary loop through a heat transfer pipe, heating the feed water to boiling, and generating dry saturated steam for driving a steam turbine after steam-water separation; the first safety barrier is used as a first loop pressure boundary, bears the first loop pressure, and forms a third safety barrier for preventing the radioactive fission product from overflowing together with other first loop pressure boundaries; and the reliable operation of the reactor device is ensured under the expected operation event, the design benchmark accident condition and the transition condition. Practical operation experience shows that whether the steam generator can safely and reliably operate has very important influence on the economy, safety and reliability of the whole nuclear power plant.

Pressurized water reactor nuclear power plants typically employ vertical, natural circulation, U-tubes, and shell and tube steam generators. The U-shaped tube type heat exchanger is a tube-shell type heat exchanger with a tube bundle composed of U-shaped tubes with different bend pipe radiuses and two ends of each tube fixed on the same tube plate. Because each U-shaped pipe can freely stretch out and draw back, the temperature difference stress can not be produced between the tube bundle and the shell. A baffle plate, a longitudinal baffle plate and the like are arranged in the shell pass. The baffle plate is fixed by a pull rod. The longitudinal partition is a rectangular flat plate and is arranged in a direction parallel to the heat transfer pipe to increase the flow velocity of the shell-side medium. The structure is more complex than that of a fixed tube-plate heat exchanger and is simpler than that of a floating head heat exchanger.

The U-shaped tube shell and tube steam generator for the pressurized water reactor nuclear power station has the working principle that: the coolant flowing out of the reactor enters the water chamber through the heat pipe section of the primary loop and is close to the inlet of the lower end socket of the steam generator, then flows in the inverted U-shaped pipe bundle, the outer surface of the inverted U-shaped pipe is in contact with the feed water of the secondary loop, and transfers the heat to the water of the secondary loop to vaporize the water, thereby completing the heat exchange between the primary loop and the secondary loop. After the heat carried by the coolant in the primary circuit is transferred to the secondary circuit, the temperature is reduced, and the heat flows through the outlet water chamber and the outlet connecting pipe of the lower end socket, flows to the transition pipeline of the primary circuit and then enters the suction inlet of the main pump. The water supply of the two loops enters a water supply ring pipe from a water supply connecting pipe of the steam generator, enters an annular space (namely a descending channel) between the lower barrel and the pipe bundle sleeve through a group of inverted J-shaped pipes on the ring pipe, flows downwards after being mixed with the water separated by the steam-water separator until reaching a bottom pipe plate, then turns, flows upwards along the outside of the pipe (namely an ascending channel) of the inverted U-shaped pipe bundle, is heated by a primary loop coolant flowing in the heat transfer pipe, and part of the water is evaporated into steam. The steam-water mixture leaves the top of the inverted U-shaped pipe bundle and continuously rises, and then sequentially enters the rotary vane type steam-water separator and the dryer, after steam-water separation, steam flows to the steam turbine from the top outlet of the steam generator to do work, and separated water is downwards mixed with feed water to be recycled. Steam generator secondary loop side fluid flow is typically driven by natural circulation; the tube bundle sleeve divides the water on the secondary side into an ascending channel and a descending channel; the mixture of low-temperature water and saturated water separated by the steam-water separator flows in the descending channel and belongs to single-phase water (supercooled water), the mixture of steam and water flows in the ascending channel, the density of the single-phase water is higher than that of the mixture of steam and water under the same pressure, the difference in density between the single-phase water and the mixture of steam and water causes pressure difference on two sides of the tube bundle sleeve, the water in the descending channel is driven to continuously flow to the ascending channel, and natural circulation is established.

According to the statistics of accidents of a pressurized water reactor nuclear power plant, the steam generator is in the leading position in the accidents of the nuclear power plant. The reliability of some steam generators is relatively low and evaporator tube breakage has a significant impact on the safety, reliability and economic benefits of nuclear power plants. Therefore, research and improvement of the steam generator are taken as important links for perfecting the technology of the pressurized water reactor nuclear power plant in all countries, and a huge scientific research plan is made, which mainly comprises thermal hydraulic analysis of the steam generator; corrosion theory and heat transfer tube material development; nondestructive inspection technology; vibration, abrasion and fatigue research; the structural design is improved, and the concentration of corrosive chemicals is reduced; improved water quality control, etc.

The high-temperature gas cooled reactor nuclear power plant selects a spiral coil type evaporator. The steam generator is a core heat exchange device for connecting and isolating the primary loop and the secondary loop, and executes a safety first-level grade, an anti-seismic I grade and a quality assurance QA1 grade. The primary function is to transmit the heat generated by the reactor core of the nuclear reactor from the primary loop to the secondary loop, generate superheated steam to drive a steam turbine to do work and generate electricity through a generator. The high-temperature gas cooled reactor evaporator adopts a vertical direct-current countercurrent component type design structure, is arranged side by side with a reactor pressure vessel, and is placed in an evaporator pressure-bearing shell together with a main helium fan. The evaporator heat exchange unit is positioned at the lower part of the pressure-bearing shell and mainly comprises a heat exchange assembly, a main steam connecting tube bundle, a main water supply connecting tube bundle, a tube box, a heat preservation layer, a bearing plate, a positioning plate, an internal component bearing cylinder, a heat compensation assembly, a cold helium gas ascending tube, a connecting flange, other internal components and the like. The single evaporator is composed of 19 heat exchange components to form a heat exchange unit, each heat exchange component is provided with 35 heat exchange tubes, and the heat exchange tubes are arranged in an annular space between the outer sleeve and the central tube. The heat exchange tube adopts a spiral coil tube structure, each heat exchange assembly is provided with 5 layers of spiral coil tube type heat exchange tubes, and the number of the heat exchange tubes on each layer is 5, 6, 7, 8 and 9 in sequence from inside to outside. The winding directions of two adjacent layers of spiral coils are opposite, and each layer of heat transfer pipe bundle is fixed through three groups of supporting structures. In order to improve the economy of equipment, materials of the heat exchange tube are selected in sections; mature and cheap T22 pipes are adopted in the preheating section, the evaporation section and a small part of the overheating section of the heat exchange tube, and high-temperature alloy pipes are adopted in the high-temperature overheating section of the heat exchange tube. In order to improve the compactness of the evaporator and reduce the heat exchange area and the volume of the evaporator, a counter-flow arrangement mode is selected on the flow modes of the primary side and the secondary side. In order to meet the requirements of stability of gas-liquid two-phase flow in the heat exchange tubes and flow distribution among the heat exchange tubes, a throttling resistance piece is additionally arranged at the inlet of each heat exchange tube of the evaporator.

The spiral coil type heat exchanger/evaporator is made by arranging one or more groups of pipes wound into a spiral shape in a shell; the spiral wound tube type heat exchanger is manufactured by manufacturing a plurality of heat exchange tubes into a coil pipe, and then stacking the coil pipe on a central circular tube; the heat exchange tubes in the tube coil are spirally wound from inside to outside. In the heat exchange process, high-pressure working medium water and water vapor pass through the spiral tube pass from bottom to top, low-pressure working medium helium passes through the shell pass from top to bottom, and the two working media flow reversely in the axial direction. During heat exchange, high-pressure fluid flows through the inner pipe, and low-pressure fluid reversely passes through the gap between the outer pipes. Although the structure ensures that the fluid is subjected to countercurrent heat exchange, the heat exchange effect is influenced due to the existence of more airflow dead zones in the two flows, so that the total heat transfer efficiency is low. The design features of the spiral coil evaporator are compact structure, larger heat transfer area than straight pipe, small temperature difference stress, difficult cleaning in pipe, and can be used for heating or cooling fluid with higher viscosity.

The high-temperature gas cooled reactor has the inherent safety characteristic, the working medium parameter of the primary loop is higher, the helium outlet temperature reaches 750 ℃, and the high-efficiency power generation of the supercritical parameter of the secondary loop is completely supported, so that the economic efficiency of a commercial engineering project is improved. Besides the difficulty in selecting high-temperature alloy materials, the high-temperature gas cooled reactor ultra-supercritical parameter power generation has the main restriction factor that the pressure bearing reliability of a working medium of a secondary loop of a spiral coil pipe steam generator is insufficient within the working pressure of 25 MPa-35 MPa and the working temperature range of 600-700 ℃, and the pipe breakage accident is easy to happen after long-term operation. The reason is that the high-temperature endurance strength and the high-temperature creep property of the high-temperature alloy material which can resist the working temperature of 750 ℃ are usually not high (for example, the high-temperature endurance strength of the high-temperature alloy material at 760 ℃ is about 100 MPa), and the high-temperature endurance strength and the high-temperature creep property of the high-temperature alloy material which can resist the working temperature of 750 ℃ are superposed on the high-temperature endurance strength and the high-temperature creep property to require the heat transfer pipe to bear ultrahigh pressure, the wall thickness of the heat transfer pipe is increased in multiples, the heat transfer coefficient is reduced in multiples, the manufacturing cost of the evaporator equipment is increased in multiples along with the high-temperature endurance strength, the pressure-.

In the future, the parameters of the primary loop working medium of the ultra-high temperature gas cooled reactor for hydrogen production and hydrogen smelting are increased to 950 ℃, and heat needs to be transferred to a 900 ℃ intermediate helium loop through a helium intermediate heat exchanger, so that the harsh extreme high temperature provides more serious challenges for the design and operation of a high temperature gas cooled reactor steam generator.

In the future, pressurized water reactor nuclear power stations also face the market requirement of ultra-supercritical power generation, and U-shaped tube shell-and-tube evaporators cannot technically meet the heat transfer requirement of extremely high temperature or extremely high pressure. Even if the working pressure and the working temperature of the current primary loop are met, the U-shaped tube shell-and-tube evaporator is high in cost in design and manufacture because the heat transfer tube material cannot be used along with the temperature field in a gradient manner, and has the design potential that the cost is reduced by one third.

The method has the following defects: whether the U-shaped tube evaporator of the pressurized water reactor or the spiral coil evaporator of the high-temperature gas-cooled reactor is adopted, the design scheme of the shell-and-tube evaporator exposes the insufficient reliability of equipment under the severe conditions of extreme high temperature or extreme high pressure or the severe conditions of ultra-high temperature and ultra-high pressure (such as ultra-supercritical power generation parameters), the tube breakage of a heat transfer tube is easily caused, and even the soft rib of a large-break accident is generated, thus threatening the safety of a nuclear reactor; and the equipment cost of the traditional design scheme is too expensive, and the economic efficiency of the project is seriously influenced.

Disclosure of the invention

The invention provides a design scheme of a brand-new heat exchanger/evaporator suitable for extremely high temperature or extremely high pressure, which utilizes a pore channel arranged in a heat exchange unit module to exchange heat and is called as a pore channel type heat exchanger/evaporator. The heat exchange between the pore passages of the small holes or the micropores which mainly take the heat conduction of the heat transfer material is adopted, and the heat transfer coefficient is higher; the heat transfer between the pore canals can be safely and stably carried out under the condition of extreme high temperature or extreme high pressure, and the heat transfer device has the characteristics of high efficiency, simplicity, safety and reliability.

The design scheme of the ultra-high temperature and ultra-high pressure pore channel type heat exchanger/evaporator is shown in figures 1 and 2 and mainly comprises a heat exchange unit (1), a primary side pore channel (T1), a secondary side pore channel (T2), a primary side baffle plate (2), a secondary side baffle plate (3), a pressure-bearing inner cylinder (4), an inner cylinder heat insulation layer (5), a heat insulation layer fixing cylinder (6), a pressure-bearing outer cylinder (7), a primary side inflow pipeline (8), an inflow pipe heat insulation layer (9), an inflow heat insulation fixing cylinder (10), a primary side backflow pipeline (11), a secondary side inflow pipeline (12), a secondary side outflow pipeline (13), an outflow pipe heat insulation layer (14), an outflow heat insulation fixing cylinder (15), an inner cylinder top head (16), an inner cylinder head heat insulation layer (17), a heat insulation fixing head (18), an inner cylinder bottom sealing plate (19), an outer cylinder top head (, The heat exchange unit is mainly structurally characterized in that two working surfaces (A1, A2) of a heat exchange unit (1) are provided with primary side pore channels (T1) according to high-temperature and high-pressure bearing strength calculation and thermal fluid heat transfer analysis of a heat exchange unit material, and the number, size, shape, path, bending, flow resistance, position relation, form and position tolerance and surface roughness of the primary side pore channels are determined through design calculation; the other two working faces (B1, B2) are provided with secondary side pore channels (T2) according to the calculation of the high-temperature and high-pressure bearing strength of the heat exchange unit material and the heat transfer analysis of the thermal fluid, and the number, the size, the shape, the path, the bending, the straight flow resistance, the position relation, the form and position tolerance and the surface roughness of the secondary side pore channels are determined through design calculation; the primary side working medium flows in a primary side pore passage (T1) of the heat exchange unit after being introduced from a primary side inflow pipeline (8), and flows out from a primary side return pipeline (11) after heat exchange (heat dissipation) is finished; a secondary side working medium is introduced from a secondary side inflow pipeline (12) and then flows in a secondary side pore passage (T2) of the heat exchange unit, and flows out from a secondary outflow pipeline (13) after heat exchange is finished (heat absorption); the primary side pore passage and the secondary side pore passage are not communicated with each other and have certain pressure bearing capacity (working pressure difference between the primary side working medium and the secondary side working medium) under certain temperature condition; the countercurrent convection heat transfer function of the primary side working medium and the secondary side working medium which mainly take heat conduction of heat exchange unit materials and take heat radiation and heat convection as auxiliary parts is realized.

The technical principle of the invention is as follows: the heat exchange unit is internally provided with formed small holes or micropores which are tightly attached to the multilayer metal for heat conduction and heat transfer, and the heat transfer coefficient is far higher than that of the wall surface of the shell-and-tube heat transfer pipe for heat radiation and heat transfer; the heat exchange between the pore passages of the small holes or the micropores mainly based on the heat conduction of the heat transfer material has the advantages of high heat transfer coefficient, safe and stable heat transfer between the pore passages under the condition of extreme high temperature or extreme high pressure, high efficiency, simplicity, safety and reliability; under the condition of the same size and material, the pore channel type heat exchanger can realize the dense and compact arrangement of multilayer pore channels, while the shell-and-tube type heat exchanger cannot compactly arrange a heat transfer pipe due to the restriction of the pore bridge strength of the tube plates at two ends, and the heat transfer area of the wall surface of the multilayer pore channel is greatly increased compared with that of the heat transfer pipe; under the condition of the same heat exchange capacity, the pore channel type heat exchanger can realize smaller heat exchange temperature difference between the primary side and the secondary side than a shell-and-tube type heat exchanger. The channel type heat exchanger/evaporator has the characteristic of high thermal efficiency, only exchanges heat and does not exchange working media; the heat transfer under the severe working medium condition of extreme high temperature or extreme high pressure can be realized, the heat transfer efficiency is higher than that of a shell-and-tube heat exchanger taking heat radiation as a main part and heat conduction and heat convection as an auxiliary part, and the heat transfer temperature difference between the primary side and the secondary side is small; compared with a shell-and-tube heat exchanger with the same heat transfer capacity, the size, the weight and the cost of the channel type heat exchanger are reduced by more than one third. Under the conditions of proper heat exchange unit material selection and proper heat transfer pore channel design selection, the heat exchange unit can support heat transfer under the severe heat transfer conditions of extreme high temperature not exceeding 1000 ℃ or extreme high pressure not exceeding 1000 kilograms. Under the conditions of special heat transfer structure design and material selection, a plurality of process flows are supported by the primary side or the secondary side to be combined into one flow passage to realize the heat transfer function.

As shown in fig. 2, a plurality of heat exchange units (1) are connected in series to form a heat exchange unit group through single-side or double-side assembly welding or additive manufacturing of a non-working surface C1/C2, and a primary side baffle plate (2), a pressure-bearing inner cylinder (4), a primary side inflow pipeline (8), an inner cylinder top head (16) and an inner cylinder bottom closing plate (19) are welded or additive manufactured to form a continuously-folded primary side working medium flow channel (L1); the secondary side baffle plate (3), the pressure-bearing inner barrel (4), the secondary side inflow pipeline (12), the secondary side outflow pipeline (13), the inner barrel top head (16) and the inner barrel bottom sealing plate (19) which are welded or manufactured in an additive mode form a secondary side working medium flow channel (L2) which turns back continuously, and the heat exchange unit is mainly structurally characterized in that huge temperature difference heat transfer and temperature shock heat transfer are achieved through cascade continuous heat transfer of a plurality of heat exchange units.

An inner cylinder heat insulation layer (5) and an inner cylinder head heat insulation layer (17) are arranged on one sides, close to the pressure-bearing outer cylinder (7), of the pressure-bearing inner cylinder (4) and the inner cylinder head (16), and the heat-conducting and heat-radiating heat-insulating heat-blocking device. The primary side inflow pipeline (8) and the secondary side outflow pipeline (13) are provided with an inflow pipe heat-insulating layer (9) and an outflow pipe heat-insulating layer (14) in the same way to block heat loss, and the heat-insulating layers are tightly attached and tightly fixed by a heat-insulating layer fixing cylinder (6), a heat-insulating fixing end socket (18), an inflow heat-insulating fixing cylinder (10) and an outflow heat-insulating fixing cylinder (15) respectively.

A primary side cold end working medium backflow channel (L3) is formed between the pressure-bearing outer cylinder (7) and the pressure-bearing inner cylinder (4) and between the primary side backflow pipeline (11) and the primary side inflow pipeline (8) and flows out through the primary side backflow pipeline (11), and the cold-heat-insulation-free cold-end cold. In principle, working media with lower pressure are usually selected as primary side working media, so that the pressure-bearing outer cylinder only bears low-temperature low-pressure primary side cold end working media after heat exchange, the difficulty of material selection is reduced, and a mature heat-resistant steel pressure-bearing material can be usually selected. Under the condition of extreme high temperature of the primary side and the secondary side, although the pressure-bearing inner barrel (4) bears higher temperature, the selection surface of the high-temperature alloy material is limited, but because the pressure-bearing inner barrel (4) only bears the working pressure difference between the primary side and the secondary side, compared with the pressure-bearing inner barrel which is only required for bearing larger secondary side high pressure, the consumption of expensive high-temperature alloy material is greatly reduced, and the equipment cost of a heat exchanger or an evaporator is reduced to a certain extent.

Inside the group of the heat exchange units (1) connected in series, the temperature fields of the primary side working medium flow channel (L1) and the secondary side working medium flow channel (L2) gradually decrease along with the flow field of the working medium along with the continuous back-turning heat transfer of the primary side working medium and the secondary side working medium; the heat exchange unit (1) and the pressure-bearing inner barrel (4) can be configured and selected from proper heat-resistant pressure-bearing materials according to the descending degree and the direction gradient of a temperature field, for example, expensive high-temperature alloy materials are selected in an extreme high-temperature section, mature heat-resistant pressure-bearing materials are selected in a common high-temperature section and a middle high-temperature section, and pressure-bearing materials with low manufacturing cost are selected in a low-temperature section.

A pressure boundary of a primary side cold end working medium pressure-bearing shell is formed by a pressure-bearing outer cylinder (7), an outer cylinder top head (20), an outer cylinder bottom head (21), a pressure-bearing outer cylinder flange (22), a pressure-bearing head flange (23), a pressure-bearing flange sealing ring (24) and a pressure-bearing flange fastener (25), and the flange is used for opening a pressure-bearing inner cylinder welding line of the pressure-bearing shell in service inspection, and inspecting, maintaining or blocking a pore channel; a hemispherical blind flange (27), a blind flange seal (28) and a blind flange fastener (29) are arranged at the bottom end socket (21) of the outer cylinder and are used for overhauling a primary side working medium forced circulation pump or a fan (26) to prevent the primary side working medium from leaking, and the outer cylinder is particularly suitable for the primary side working medium with radioactivity. A hanging basket is arranged on the upper portion of the inner wall of the pressure-bearing outer cylinder, or a bracket is arranged on the lower portion of the inner wall of the pressure-bearing outer cylinder, so that the weight of the heat exchange unit can be transmitted to an external foundation or supported through the outer cylinder, and spring dampers (solid springs, hollow springs, disc springs and the like) are embedded into the hanging basket and the bracket to absorb thermal expansion generated under the thermal working condition of the heat exchange unit.

The duct for heat transfer is typically specifically designed according to the heat transfer performance of the structural material and the pressure-bearing function of the working medium, and meanwhile, the convenience of the duct processing technology is considered, and sometimes the flow resistance characteristic of the duct is also considered. As shown in fig. 1, the cross-sectional shape of the cell channels may be generally circular, oblong, elliptical, semicircular, rectangular, diamond-shaped, triangular, polygonal, irregular, etc.; the pore canal can also be designed into a non-uniform cross section shape along the flowing direction of the working medium, such as a continuous conical pore canal; the non-circular pore canal is easy to generate stress concentration and micro defects in the processing process, and is not recommended to be selected under the working condition of high-pressure fluid; circular, long circular, elliptical and semicircular channel sections are preferred, the diameter (2a) of the major axis of the ellipse of the primary side channel and the diameter (2r) of the semicircle of the secondary side channel are parallel to the non-working surface C1\ C2 of the heat exchange unit, and the diameter (2b) of the minor axis of the ellipse of the primary side channel and the diameter (2r) of the semicircle of the secondary side channel are perpendicular to the non-working surface C1\ C2 of the heat exchange unit, so that the number of the heat exchange channels can be increased under the condition of ensuring the heat transfer coefficient and the pressure bearing function, and the heat exchange area is. The internal flow channel of the pore channel can be understood as or equal to an inner wall tube of the heat transfer tube, the two functional structures are completely similar, the size and the dimension of the pore channel are determined by combining the heat transfer performance of working fluid and the pressure bearing function of heat exchange materials, a wall thickness inter-pore bridge (h1) is reserved between the pore channel and the pore channel to meet the requirement of pressure bearing strength, and a certain wall thickness inter-pore bridge (h2) is arranged between the primary side pore channel and the secondary side pore channel to prevent the working medium at a high pressure end from leaking to a lower pressure medium end; in general, small-sized pores or micropores can bear high pressure or extremely high pressure, and can not cause the breakage and leakage of pore channels, but the flow resistance of the pores or micropores is larger. The heat exchange area of the pore canal is generally the product of the perimeter of the cross section of the pore canal and the length of the path of the pore canal, and the path of the pore canal in the heat exchange unit can be designed and arranged along a straight line or can be designed and arranged in a path bending way; the straight-through hole channel is convenient for processing and forming in various processing modes and controlling the form and position tolerance precision, and the bent hole channel is limited in general processing technology and higher in processing cost; the surface roughness of the inner wall of the duct influences the flow resistance, and the flow resistance of the smooth inner wall surface is generally smaller.

After the size and the cross-sectional shape of the through hole are designed and determined, the technical requirements on the straightness and the surface roughness of the hole are generally set on a design drawing; a plurality of pore channels of a primary side or a secondary side are generally arranged in the heat exchange unit, the technical requirements of position tolerance and parallelism form and position tolerance should be provided between the pore channel of the primary side and the axial lead of the pore channel, and the technical requirements of position tolerance and parallelism form and position tolerance between the pore channel of the secondary side and the pore channel are also provided between the pore channel of the secondary side; the technical requirements of form and position tolerance of position degree and verticality (or space included angle precision) are required to be provided between the primary side pore canal and the secondary side pore canal. The processing precision requirements aim at ensuring the quality level of the pore channels and preventing the wall thickness of the material between the pore channels from being reduced and weakened due to processing deviation in the pore channel processing process so as to generate the accident of broken pipe and pressure loss. According to the size and the cross-sectional shape of the pore canal, the pore canal is generally processed and formed by deep hole drilling, 3D printing additive manufacturing, chemical etching of a multilayer board, vacuum molecular diffusion welding, wire cutting and the like.

(IV) description of the drawings

FIG. 1 is a schematic diagram of a pore structure of a heat exchange unit in the pore heat exchanger.

Fig. 2 is a schematic structural diagram of the application of the present invention to a steam generator/intermediate heat exchanger of a high temperature gas cooled reactor or an ultra high temperature gas cooled reactor.

FIG. 3 is a schematic structural view of the present invention in application to a steam generator of a pressurized water reactor nuclear power plant or a supercritical pressurized water reactor nuclear power plant. The structural schematic diagram of fig. 3 is essentially a modified design scheme of the structural schematic diagram of fig. 2, and the difference is that heat exchange units B1 and B2 are used as non-working surfaces, surfaces C1 and C2 are used as secondary side pore canal working surfaces, and a plurality of heat exchange units are sequentially subjected to laser narrow gap welding or TIG narrow gap welding to form a multi-stage through-hole channel from top to bottom according to the condition that the working surface C faces the working surface C. The structural design has the advantages that the pore passage can be inspected in service, and is particularly suitable for heat transfer of high-pressure fluid; the design structure that the working face is welded in sequence also saves a secondary side baffle plate and a secondary side part of the pressure-bearing inner cylinder.

FIG. 4 is a schematic structural diagram of the present invention in the application of an integrated shell pressurized water nuclear power reactor, nuclear heat supply reactor or nuclear power plant annular heat exchanger. The schematic structure of fig. 4 is essentially a simplified design variant of the schematic structure of fig. 3. The simplification is that the pressure-bearing outer cylinder is removed, and the pressure-bearing inner cylinder is directly used as a pressure-bearing boundary of the two loops; the deformation is that the working surfaces of A1 and A2 are changed into outer cylindrical and inner cylindrical working surfaces (annular heat exchanger) or outer and inner cylindrical surfaces (sector heat exchanger).

(V) detailed description of the preferred embodiments

Figure 2 shows an embodiment of the invention in a high temperature gas cooled reactor or ultra high temperature gas cooled reactor steam generator/intermediate heat exchanger application.

The design scheme is very suitable for the design scheme of the steam generator for the ultra-supercritical parameter power generation of the high-temperature gas cooled reactor, the ultra-high temperature superimposed ultra-high pressure technical parameters are the design difficulty and pain point of the design scheme, and the design scheme of the spiral coil type evaporator is not enough in the reliability of a heat transfer pipe under the ultra-high temperature and ultra-high pressure design condition and is easy to cause pipe breaking and water loss accidents. A primary side working medium of the high-temperature gas cooled reactor is hot helium with working pressure of 8MPa and working temperature of 750 ℃, the hot helium flows into a half-moon-shaped inflow space which is welded and enclosed by a primary side heat exchange unit (1) and a pressure-bearing inner barrel (4) through a primary side inflow pipeline (8), a primary side pore passage (T1) is forcibly introduced due to high pressure of the working medium, the hot helium flows out of the half-moon-shaped outflow space which is enclosed by a final stage heat exchange unit (1) and the pressure-bearing inner barrel (4) to a primary side working medium forced circulation fan (26) after being guided and continuously turned back to transfer heat through a heat exchange unit pore passage and a primary side baffle plate (2), and the working medium entering the fan is cold helium with working pressure slightly lower than 8. The secondary side is deionized demineralized water with the working pressure of 25MPa and the working temperature of 205 ℃, the deionized demineralized water flows into a half-moon-shaped inflow space enclosed by the final-stage heat exchange unit (1) and the pressure-bearing inner barrel (4) through a secondary side inflow pipeline (12), a secondary side pore channel (T2) is forcibly introduced by the working pressure of the high-pressure water replenishing pump, and after heat transfer activities such as guiding, continuous return preheating, heating, evaporation, overheating and the like of a heat exchange unit pore channel and a secondary side baffle plate (2), the half-moon-shaped outflow space enclosed by the first-stage heat exchange unit (1) and the pressure-bearing inner barrel (4) flows out to a secondary side outflow pipeline (13), so that superheated steam with the working pressure slightly lower than 25MPa and the working temperature of 630-700 ℃ is formed, and the superheated. The materials of the heat exchange unit (1) and the pressure-bearing inner cylinder (4) are martensite heat-resistant stainless steel in the preheating section of water, ferrite heat-resistant steel for the steam turbine cylinder body is selected in the heating section and the evaporation section, and high-temperature nickel-based alloy is selected as the material of the overheating section.

The embodiment is also very suitable for the design scheme of the intermediate heat exchanger of the ultra-high temperature gas cooled reactor in the field of hydrogen production or hydrogen smelting. The intermediate heat regenerator is a primary loop pressure-bearing boundary of the ultra-high temperature gas cooled reactor, only exchanges heat with a user loop through the intermediate heat regenerator and does not exchange working media, the secondary side pressure is higher than the primary side pressure, the main function is to prevent the radioactive working media of the primary loop from escaping, the extreme high temperature is a design difficulty and a pain point of the intermediate heat exchanger of the ultra-high temperature gas cooled reactor, the shell-and-tube intermediate heat regenerator is complex in structure and high in manufacturing cost, and potential tube breaking risks exist in the operation process. The inflow working medium at the primary side of the ultra-high temperature gas cooled reactor is hot helium with the working pressure of 8MPa and the working temperature of 950 ℃, and the cold helium with the working pressure of slightly lower than 8MPa and the working temperature of 250 ℃ is formed after heat transfer with the secondary side; the secondary side inflow working medium is cold helium with the working temperature of 200 ℃ and the working pressure of 9MPa, and hot helium with the working temperature of 900 is generated after heat transfer with the primary side. The working principle of the device is the same as that of a steam generator for high-temperature gas cooled reactor ultra-supercritical power generation. The material selection logic is similar, and the material is selected according to the temperature field gradient.

FIG. 3 is an embodiment of the present invention in a steam generator application in a pressurized water reactor nuclear power plant or a supercritical pressurized water reactor nuclear power plant.

The design scheme is suitable for a steam generator design scheme for a pressurized water reactor nuclear power station, the ultrahigh pressure superposition high temperature technical parameters are the design difficulty of the embodiment, the design scheme of the U-shaped tubular evaporator is mature under the ultrahigh pressure superposition high temperature design condition, the pipe breaking and blocking accidents of heat transfer pipes often occur, the equipment reliability still needs to be improved, the cost of equipment is too high due to the selection of more than ten thousand high-temperature alloy heat transfer pipes, and the selected pore channel type evaporator has the potential of greatly reducing the cost. The primary side working medium of the pressurized water reactor nuclear power station is hot demineralized water with working pressure of 15.5-17.3 MPa and working temperature of 325-340 ℃, the hot demineralized water flows into a half-moon-shaped inflow space welded and enclosed by the primary heat exchange unit (1) and the pressure-bearing inner barrel (4) through a primary side inflow pipeline (8), a primary side hole channel (T1) is forcibly introduced due to high pressure of the working medium, the working medium flows out of the half-moon-shaped outflow space enclosed by the final heat exchange unit (1) and the pressure-bearing inner barrel (4) after being guided by a heat exchange unit hole channel and a primary side baffle plate (2) and continuously returned for heat transfer, and the working medium is cold demineralized water with working pressure slightly lower than 15.5-17.3 MPa and working temperature of 280-290 ℃. The secondary side is deionized and desalted water with the working pressure of 6-10 MPa and the working temperature of 35 ℃, the deionized and desalted water flows into the working surface below the final-stage heat exchange unit (1) through a secondary side inflow pipeline (12), the working pressure of a high-pressure water replenishing pump is forcibly introduced into a secondary side pore channel (T2), and after heat transfer activities such as preheating, heating, evaporation, drying and the like through a through pore channel formed by a plurality of heat exchange units, the deionized and desalted water flows out of the working surface on the primary-stage heat exchange unit (1) to a secondary side outflow pipeline (13), so that saturated steam with the working pressure slightly lower than 6-10 MPa and the working temperature of 270-320 ℃ is formed. The heat exchange unit (1) and the pressure-bearing inner cylinder (4) are made of martensitic stainless heat-resistant steel or austenitic stainless steel in the preheating section, the heating section and the evaporation section of water, so that the use of high-temperature alloy is avoided, and the equipment cost can be greatly reduced. In view of the fact that the primary side is higher in pressure than the secondary side, the duct needs to be checked in service during operation, and the design scheme that the primary side working medium flows through the direct-current duct is reasonable and feasible.

The embodiment is very suitable for the design scheme of the steam generator for the supercritical pressurized water reactor nuclear power station, and the ultrahigh pressure superposition ultrahigh temperature technical parameters are the design difficulty and pain points of the embodiment. The design scheme of the U-shaped tubular evaporator has insufficient reliability of a heat transfer pipe under the ultrahigh pressure superposition ultrahigh temperature design condition, and is easy to cause pipe breakage and water loss accidents; moreover, the cost of equipment is too high due to the selection of more than ten thousand high-temperature alloy heat transfer tubes, and the pore channel evaporator has the potential of greatly reducing the cost. The primary side working medium of the supercritical pressurized water reactor nuclear power station is hot demineralized water with working pressure of 23-27 MPa and working temperature of 580-600 ℃, the hot demineralized water flows into a half-moon-shaped inflow space welded and enclosed by a primary heat exchange unit (1) and a pressure-bearing inner barrel (4) through a primary side inflow pipeline (8), and because the high pressure of the working medium is forcibly introduced into a primary side channel (T1), the working medium flows out of the half-moon-shaped outflow space enclosed by the final stage heat exchange unit (1) and the pressure-bearing inner barrel (4) after being guided by a heat exchange unit channel and a primary side baffle plate (2) and continuously turned back to transfer heat, and cold demineralized water with working pressure slightly lower than 23-27 MPa and working temperature of 540-566 ℃ is generated. The secondary side is deionized and desalted water with the working pressure of 23-25 MPa and the working temperature of 35 ℃, the deionized and desalted water flows into the working surface below the final-stage heat exchange unit (1) through a secondary side inflow pipeline (12), the working pressure of a high-pressure water replenishing pump is forcibly introduced into a secondary side pore channel (T2), and after heat transfer activities such as preheating, heating, evaporation, drying and the like through a through pore channel formed by a plurality of heat exchange units, the deionized and desalted water flows out of the working surface on the primary-stage heat exchange unit (1) to a secondary side outflow pipeline (13) to form saturated steam with the working pressure slightly lower than 23-25 MPa and the working temperature of 566-580 ℃ parameters. The heat exchange unit (1) and the pressure-bearing inner cylinder (4) are made of martensitic stainless heat-resistant steel or austenitic stainless steel in a preheating section, a heating section and an evaporation section of water, and high-temperature alloy is selected for the evaporation section and the overheating section, so that the design scheme is efficient and reliable, and the equipment cost can be greatly reduced. In view of the fact that the primary side is higher in pressure than the secondary side, the duct needs to be checked in service during operation, and the design scheme that the primary side working medium flows through the direct-current duct is reasonable and feasible.

FIG. 4 shows an embodiment of the invention in the application of an integrated shell-type pressurized water nuclear power reactor, nuclear heat supply reactor or nuclear power plant annular heat exchanger.

The embodiment is particularly suitable for the design scheme of the annular heat exchanger which is formed by combining an integrated shell type pressurized water nuclear power reactor, a nuclear heat supply reactor or a nuclear power station in an annular shape or a plurality of sectors, has the design advantages of visual thermal technology principle, simple, compact and practical structure, high heat transfer efficiency, small temperature difference of a first loop and a second loop, small volume and weight and easy suspension on the inner wall of the pressure vessel. The primary side working medium is a hot fluid which flows through the reactor core and rises in a natural circulation or forced circulation mode, enters a plurality of vertical channels on the primary side to exchange heat with the secondary side fluid when rising to the upper working surface of the annular channel heat exchanger, and becomes a cold fluid after flowing out of the lower working surface of the channel heat exchanger; the secondary side cold fluid flows into the outer annular working surface of the channel type heat exchanger from the interlayer of the inner pipe and the outer pipe of the double-layer sleeve, passes through a plurality of channels (which can also be designed into conical channels) and inner annular working surfaces which are distributed in a spoke shape and point to the reactor core, and is continuously returned, preheated and heated to generate hot fluid which flows out from the inner pipe of the double-layer sleeve.

The design scheme of the deformed annular duct type heat exchanger in the embodiment is that the annular duct type heat exchanger is formed by combining a plurality of fan-shaped duct type heat exchangers, and the difference from the embodiment shown in the attached figure 4 is that the working surfaces of the secondary side are not the outer curved surface and the inner curved surface of the fan surface, but two side planes of the fan surface; and a plurality of pore channels of the secondary side are distributed in an arc shape in the heat exchange unit between the inner curved surface and the outer curved surface. The side plane of the fan-shaped pore channel type heat exchanger is provided with two loops of continuously-folded baffle plates, so that the heat transfer function and efficiency of the fan-shaped pore channel type heat exchanger are inferior to those of an integral annular heat exchanger.

The above examples are only for illustrating the present invention and are not to be construed as limiting the present invention. According to the technical principle of the invention, the design scheme of the hole type heat exchanger and the evaporator can be designed in various modifications by ordinary technicians. The scope of the invention is defined by the following claims.

Claims

1. A design scheme of an ultrahigh-temperature and ultrahigh-pressure pore-channel type heat exchanger/evaporator is shown in figures 1 and 2 and comprises a heat exchange unit (1), a primary side pore channel (T1), a secondary side pore channel (T2), a primary side baffle plate (2), a secondary side baffle plate (3), a pressure-bearing inner cylinder (4), an inner cylinder heat-insulating layer (5), a heat-insulating layer fixing cylinder (6), a pressure-bearing outer cylinder (7), a primary side inflow pipeline (8), an inflow heat-insulating layer flow pipe (9), an inflow heat-insulating fixing cylinder (10), a primary side backflow pipeline (11), a secondary side inflow pipeline (12), a secondary side outflow pipeline (13), an outflow pipe heat-insulating layer (14), a heat-insulating fixing cylinder (15), an inner outflow cylinder top head (16), an inner cylinder heat-insulating layer (17), a heat-insulating fixing head (18), an inner cylinder bottom sealing plate (, The heat exchange unit is mainly structurally characterized in that two working faces (A1, A2) of a heat exchange unit (1) are provided with primary side pore channels (T1) according to high-temperature and high-pressure bearing strength calculation and thermal fluid heat transfer analysis of a heat exchange unit material, and the number, size, shape, path, bending, straightness, flow resistance, position relation, form and position tolerance and surface roughness of the primary side pore channels are determined through design calculation; the other two working faces (B1, B2) are provided with secondary side pore channels (T2) according to the calculation of the high-temperature and high-pressure bearing strength of the heat exchange unit material and the heat transfer analysis of the thermal fluid, and the number, the size, the shape, the path, the bending, the straight flow resistance, the position relation, the form and position tolerance and the surface roughness of the secondary side pore channels are determined through design calculation; the non-working surface of the heat exchange unit is a (C1, C2) surface.

The primary side working medium flows in a primary side pore passage (T1) of the heat exchange unit after being introduced from a primary side inflow pipeline (8), and flows out from a primary side return pipeline (11) after heat exchange (heat dissipation) is finished; a secondary side working medium is introduced from a secondary side inflow pipeline (12) and then flows in a secondary side pore passage (T2) of the heat exchange unit, and flows out from a secondary outflow pipeline (13) after heat exchange is finished (heat absorption); the primary side pore passage and the secondary side pore passage are not communicated with each other and have certain pressure bearing capacity (working pressure difference between the primary side working medium and the secondary side working medium) under certain temperature condition; the countercurrent convection heat transfer function of the primary side working medium and the secondary side working medium which mainly take heat conduction of heat exchange unit materials and take heat radiation and heat convection as auxiliary parts is realized. Because the pore channel type heat transfer forms close-fitting type multilayer metal heat conduction heat transfer in the heat exchange unit, the heat transfer coefficient is far higher than that of the heat radiation heat transfer of the wall surface of the shell-and-tube heat transfer pipe; under the condition of the same size and material, the pore channel type heat exchanger can realize the dense and compact arrangement of multilayer pore channels, while the shell-and-tube type heat exchanger cannot compactly arrange a heat transfer pipe due to the restriction of the pore bridge strength of the tube plates at two ends, and the heat transfer area of the wall surface of the multilayer pore channel is greatly increased compared with that of the heat transfer pipe; under the condition of the same heat exchange capacity, the pore channel type heat exchanger can realize smaller heat exchange temperature difference between the primary side and the secondary side than a shell-and-tube type heat exchanger. The channel type heat exchanger/evaporator has the characteristics of high thermal efficiency, is simple, practical, safe and reliable, and only exchanges heat but not exchanges working media; the heat transfer under the severe working medium condition of extreme high temperature or extreme high pressure can be realized, the heat transfer efficiency is higher than that of a shell-and-tube heat exchanger taking heat radiation as a main part and heat conduction and heat convection as an auxiliary part, and the heat transfer temperature difference between the primary side and the secondary side is small; compared with a shell-and-tube heat exchanger with the same heat transfer capacity, the size and the weight of the pore channel type heat exchanger are reduced by more than 30 percent. Under the conditions of proper heat exchange unit material selection and proper heat transfer pore channel design selection, the heat exchange unit can support heat transfer under the severe heat transfer conditions of extreme high temperature not exceeding 1000 ℃ or extreme high pressure not exceeding 1000 kilograms. Under the conditions of special heat transfer structure design and material selection, a plurality of process flows are supported by the primary side or the secondary side to be combined into one flow passage to realize the heat transfer function.

A plurality of heat exchange units (1) are assembled and welded or manufactured in an additive mode on a single side of a non-working surface C1 or on two sides of C1\ C2 to form a heat exchange unit group in series, and a continuously-folded primary side working medium flow channel (L1) is formed by a primary side baffle plate (2), a pressure-bearing inner cylinder (4), a primary side inflow pipeline (8), an inner cylinder top head (16) and an inner cylinder bottom closing plate (19) which are welded or manufactured in an additive mode; the secondary side baffle plate (3), the pressure-bearing inner barrel (4), the secondary side inflow pipeline (12), the secondary side outflow pipeline (13), the inner barrel top head (16) and the inner barrel bottom sealing plate (19) which are welded or manufactured in an additive mode form a secondary side working medium flow channel (L2) which turns back continuously, and the heat exchange unit is mainly structurally characterized in that huge temperature difference heat transfer and temperature shock heat transfer are achieved through cascade continuous heat transfer of a plurality of heat exchange units.

A primary side cold end working medium backflow channel (L3) is formed between the pressure-bearing outer cylinder (7) and the pressure-bearing inner cylinder (4) and between the primary side backflow pipeline (11) and the primary side inflow pipeline (8) and flows out through the primary side backflow pipeline (11), and the cold-heat-insulation-free cold-end cold. In principle, working media with lower pressure are usually selected as primary side working media, so that the pressure-bearing outer cylinder only bears low-temperature low-pressure primary side cold end working media after heat exchange, the difficulty of material selection is reduced, and a mature heat-resistant steel pressure-bearing material can be usually selected. Under the condition of extreme high temperature of the primary side and the secondary side, although the pressure-bearing inner barrel (4) bears higher temperature, the selection surface of the high-temperature alloy material is limited, the pressure-bearing inner barrel (4) only bears the working pressure difference between the primary side and the secondary side, and compared with the pressure-bearing inner barrel which is only required for bearing larger secondary side high pressure, the consumption of expensive high-temperature alloy material is greatly reduced, and the manufacturing cost of heat exchanger equipment is reduced to a certain extent.

In the heat exchange unit (1) group connected in series, along with the continuous back-turning heat transfer of the primary side working medium and the secondary side working medium, the temperature fields of the primary side working medium flow passage (L1) and the secondary side working medium flow passage (L2) are gradually decreased along with the flow field of the working medium; the heat exchange unit (1) and the pressure-bearing inner barrel (4) can be configured and selected from proper heat-resistant pressure-bearing materials according to the descending degree and the direction gradient of a temperature field, for example, expensive high-temperature alloy materials are selected in an extreme high-temperature section, mature heat-resistant pressure-bearing materials are selected in a common high-temperature section and a middle high-temperature section, and pressure-bearing materials with low manufacturing cost are selected in a low-temperature section.

A pressure boundary of a primary side cold end working medium pressure-bearing shell is formed by a pressure-bearing outer cylinder (7), an outer cylinder top head (20), an outer cylinder bottom head (21), a pressure-bearing outer cylinder flange (22), a pressure-bearing head flange (23), a pressure-bearing flange sealing ring (24) and a pressure-bearing flange fastener (25), and the flange is used for opening a pressure-bearing inner cylinder welding line of the pressure-bearing shell in service inspection, and inspecting, maintaining or blocking a pore channel; the outer cylinder bottom end enclosure (21) is provided with a pressure maintaining overhauling core-pulling cylinder (27), a hemispherical blind flange (28), a blind flange seal (29) and a blind flange fastener (30) for pressure maintaining overhauling of a primary side working medium forced circulation pump or a fan (26) to prevent leakage of the primary side working medium, and the outer cylinder bottom end enclosure is particularly suitable for the primary side working medium with radioactivity. A hanging basket is arranged at the upper part of the inner wall of the pressure-bearing outer barrel (7) and is parallel to the top end face of the heat exchange tube unit, or a bracket is arranged at the lower part of the inner wall of the pressure-bearing outer barrel and is parallel to the bottom end face of the heat exchange tube unit so as to transmit the weight of the heat exchange unit to an external foundation or support through the outer barrel, and spring dampers (solid springs, hollow springs, disc springs and the like) are embedded in the hanging basket and the bracket so as to absorb thermal expansion generated under the thermal working condition of the.

2. The design scheme of the ultra-high temperature and ultra-high pressure channel heat exchanger/evaporator according to claim 1, as shown in fig. 3, is characterized in that the heat exchange unit (1) is designed in a deformation mode, the heat exchange units B1 and B2 are used as non-working surfaces, the surfaces C1 and C2 are used as secondary side channel working surfaces, and the plurality of heat exchange units form a multi-stage through channel from top to bottom by sequentially performing high-power vacuum electron beam welding, high-power vacuum molecular diffusion welding, high-power laser self-fluxing welding, laser narrow-gap composite cladding welding or TIG narrow-gap welding on the working surface C surface according to the working surface C facing the working surface C. The structural design has the advantages that the pore passage can be inspected in service, and is particularly suitable for heat transfer of high-pressure fluid; the design structure that the working face is welded in sequence also saves a secondary side baffle plate and a secondary side part of the pressure-bearing inner cylinder. The secondary side is a working medium and flows into the lower working surface of the final-stage heat exchange unit (1) through a secondary side inflow pipeline (12), and the working medium flows out of the upper working surface of the primary-stage heat exchange unit (1) to a secondary side outflow pipeline (13) after heat transfer activities such as preheating, heating, evaporation and drying through a through hole channel formed by a plurality of heat exchange units due to the fact that the working pressure of the high-pressure water replenishing pump is forcibly introduced into a secondary side hole channel (T2). The heat exchange unit (1) and the pressure-bearing inner cylinder (4) are made of martensitic stainless heat-resistant steel or austenitic stainless steel in a preheating section, a heating section and an evaporation section of a medium, so that the use of high-temperature alloy is avoided, and the equipment cost can be greatly reduced. If the primary side pressure is higher than the secondary side pressure, in order to facilitate the service inspection of the high-pressure side duct during the operation, the primary side and the secondary side can exchange flow channels, namely the primary side high-pressure working medium flows through C1 and C2 surface multi-stage direct-current ducts, and the secondary side low-pressure working medium flows through A1 and A2 continuous return flow channels. Such a design is also reasonably feasible.

3. A design solution of a high temperature and high pressure tunnel type heat exchanger/evaporator as claimed in claim 1 and claim 2, characterized by the simplified design, which is that the pressure-bearing outer cylinder (7) is removed, and the pressure-bearing inner cylinder (4) is directly used as the pressure-bearing boundary.

4. A design solution of high temperature and high pressure channel heat exchanger/evaporator as claimed in claim 3, as shown in fig. 4, characterized by the deformation design, in which the working surfaces a1 and a2 are changed into outer and inner cylindrical working surfaces (ring heat exchanger), or outer and inner cylindrical surfaces (sector heat exchanger).

5. The design scheme of the ultra-high temperature and ultra-high pressure channel heat exchanger/evaporator or the design scheme of the high temperature and high pressure channel heat exchanger/evaporator as claimed in claim 1, claim 2, claim 3 and claim 4 is as shown in fig. 1, and is characterized in that the channel for heat transfer is specifically designed according to the heat transfer performance of the structural material and the pressure bearing function of the working medium, and meanwhile, the convenience of the channel processing technology is considered, and sometimes the flow resistance characteristic of the channel is also considered. The cross section of the pore passage can be generally round, oblong, oval, semicircular, rectangular, rhombic, triangular, polygonal, irregular and the like; the pore canal can also be designed into a non-uniform cross section shape along the flowing direction of the working medium, such as a continuous conical pore canal; the non-circular pore canal is easy to generate stress concentration and micro defects in the processing process, and is not recommended to be selected under the working condition of high-pressure fluid; circular, long circular, elliptical or semicircular channel sections are preferably recommended, the elliptical major axis diameter (2a) and the semicircular diameter chord (2r) of the primary side channel and the secondary side channel are parallel to the heat exchange unit non-working surface C1\ C2, and the elliptical minor axis diameter (2b) and the semicircular radius axis (r) of the primary side channel and the secondary side channel are perpendicular to the heat exchange unit non-working surface C1\ C2, so that the number of heat exchange channels can be increased under the condition of ensuring the heat transfer coefficient and the pressure bearing function, and the heat exchange area is increased.

6. The design scheme of the ultra-high temperature and ultra-high pressure porthole heat exchanger/evaporator or the design scheme of the high temperature and high pressure porthole heat exchanger/evaporator according to claim 5, as shown in fig. 1, is characterized in that an internal flow passage of a porthole can be understood as or equal to the inner wall of a heat transfer pipe, the two functional structures are completely similar, the size and the dimension of the porthole are determined by calculation in combination with the heat transfer performance of working fluid and the pressure-bearing function of heat exchange material, a wall thickness inter-porthole bridge (h1) is reserved between the porthole and the porthole to meet the pressure-bearing strength requirement, and a certain wall thickness porthole bridge (h2) is reserved between a primary porthole and a secondary porthole to prevent a high; in general, small-sized pores or micropores can bear high pressure or extremely high pressure, and can not cause the breakage and leakage of pore channels, but the flow resistance of the pores or micropores is larger. The heat exchange area of the pore canal is generally the product of the perimeter of the cross section of the pore canal and the length of the path of the pore canal, and the path of the pore canal in the heat exchange unit can be designed and arranged along a straight line or can be designed and arranged in a path bending way; the straight-through hole channel is convenient for processing and forming in various processing modes and controlling the form and position tolerance precision, and the bent hole channel is limited in general processing technology and high in processing cost. The surface roughness of the inner wall of the duct influences the flow resistance, and the flow resistance of the smooth inner wall surface is generally smaller.

7. The design scheme of the ultra-high temperature and ultra-high pressure hole-channel heat exchanger/evaporator or the high temperature and high pressure hole-channel heat exchanger/evaporator as claimed in claim 5, as shown in fig. 1, is characterized in that after the size and the cross-sectional shape of the through hole channel are designed, the technical requirements on the straightness and the surface roughness of the hole channel are required to be provided on a design drawing; a plurality of pore channels of a primary side or a secondary side are generally arranged in the heat exchange unit, the technical requirements of position tolerance and parallelism form and position tolerance should be provided between the pore channel of the primary side and the axial lead of the pore channel, and the technical requirements of position tolerance and parallelism form and position tolerance between the pore channel of the secondary side and the pore channel are also provided between the pore channel of the secondary side; the technical requirements of form and position tolerance of position degree and verticality (or space included angle precision) are required to be provided between the primary side pore canal and the secondary side pore canal. The processing precision requirements aim at ensuring the quality level of the pore channels and preventing the wall thickness of the material between the pore channels from being reduced and weakened due to processing deviation in the pore channel processing process so as to generate the accident of broken pipe and pressure loss. According to the size and the cross section shape of the pore channel, the porous ceramic is processed and formed by adopting deep hole drilling, 3D printing additive manufacturing, multilayer board chemical etching, vacuum diffusion welding, wire cutting and other modes.