Double-pipe heat exchanger testing device and testing method

Abstract

The invention relates to the technical field of double-pipe heat exchangers, in particular to a double-pipe heat exchanger testing device which comprises a pressure-bearing shell, an external flow channel pipe, a pipe plate assembly and a measuring assembly. The pressure-bearing shell comprises a first shell and a second shell, and the first shell is provided with a primary loop inlet and a secondary loop outlet; the second shell is provided with a secondary loop inlet, a primary loop first outlet and / or a primary loop second outlet; the outer flow channel pipe communicates with the two first shells and the second shell and is used for being arranged on the outer side of the fixed double-pipe heat exchanger in a sleeving mode. The two pressure-bearing shells are each internally provided with a set of tube plate assembly. Each set of tube plate assembly comprises a first tube plate used for fixing the inner sleeve and a second tube plate used for fixing the outer sleeve. The measuring assembly comprises a temperature measuring element and / or a pressure measuring element so as to measure the temperature and / or the pressure at the inlet and the outlet of each loop; the test device provided by the invention can be adapted to double-pipe heat exchangers with different specifications, and can simulate a real heat exchange environment and verify key design parameters in a low-cost manner.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of double-pipe heat exchanger, and particularly relates to a double-pipe heat exchanger test device and a test method. BACKGROUND

[0002] The double-pipe heat exchanger adopts a concentric double-pipe reverse flow heat exchange structure, can realize high-efficiency heat exchange in a compact space, and is suitable for nuclear energy application scenarios with small flow and low flow rate. Because a low-temperature heat supply reactor adopts natural circulation and integrated arrangement, it is urgent to use the double-pipe heat exchanger to lead out the heat of a reactor core inside a pressure vessel. However, the traditional double-pipe heat exchanger has problems of complex manufacturing process, difficult maintenance and flow-induced vibration, lacks application experience in the field of nuclear power, and must verify key design parameters through thermal test. SUMMARY

[0003] The present application provides a double-pipe heat exchanger test device and test method which can adapt to double-pipe heat exchangers of different specifications, and the device can simulate a real heat exchange environment in a low-cost manner and verify key design parameters.

[0004] The present application provides a double-pipe heat exchanger test device, which comprises:

[0005] A pressure-bearing shell comprises a first shell and a second shell, the first shell is provided with a primary loop inlet and a secondary loop outlet; the second shell is provided with a secondary loop inlet, a primary loop first outlet and / or a primary loop second outlet;

[0006] An external flow channel pipe is connected to the two first shells and the second shell, and is used for being sleeved outside the fixed double-pipe heat exchanger;

[0007] A tube plate assembly is arranged in each of the two pressure-bearing shells, and each tube plate assembly comprises a first tube plate for fixing an inner sleeve pipe of the double-pipe heat exchanger and a second tube plate for fixing an outer sleeve pipe of the double-pipe heat exchanger, wherein the inner sleeve pipe is arranged in the outer sleeve pipe;

[0008] A measurement assembly comprises a temperature measuring element and / or a pressure measuring element, and is used for measuring the temperature and / or pressure at the inlet and outlet of each loop;

[0009] The primary loop inlet, the inner cavity of the first shell, the inner sleeve pipe and the primary loop first outlet are sequentially connected; the primary loop inlet, the inner cavity of the first shell, the external flow channel pipe and the corresponding primary loop first outlet or primary loop second outlet are sequentially connected; and the secondary loop inlet, the outer sleeve pipe and the secondary loop outlet are sequentially connected.

[0010] In an embodiment of the present application, the external flow channel pipe is sleeved with at least two groups of double-pipe heat exchangers.

[0011] In an embodiment of the present application, a tube box assembly is further included, which comprises a secondary circuit outlet water tube box arranged in the first shell, and a primary circuit first outlet water tube box, a primary circuit second outlet water tube box and a secondary circuit inlet water tube box arranged in the second shell;

[0012] The primary circuit inlet, the inner cavity of the first shell, the inner sleeve, the primary circuit first outlet water tube box and the primary circuit first outlet are sequentially communicated; the primary circuit inlet, the inner cavity of the first shell, the outer flow channel tube, the primary circuit second outlet water tube box and the primary circuit second outlet are sequentially communicated.

[0013] The secondary circuit inlet, the secondary circuit inlet water tube box, the outer sleeve, the secondary circuit outlet water tube box and the secondary circuit outlet are sequentially communicated.

[0014] In an embodiment of the present application, the first tube plate in the first shell is arranged at one end of the secondary circuit outlet water tube box away from the sleeve type heat exchanger; and the second tube plate in the first shell is arranged at the other end of the secondary circuit outlet water tube box.

[0015] The first tube plate in the second shell is arranged between the primary circuit first outlet water tube box and the secondary circuit inlet water tube box; and the second tube plate in the second shell is arranged between the secondary circuit inlet water tube box and the primary circuit second outlet water tube box.

[0016] In an embodiment of the present application, a pressure dividing device is arranged in the first shell, which communicates the primary circuit inlet and the inner cavity of the first shell, and is provided with a liquid outlet hole which is misaligned with the sleeve type heat exchanger.

[0017] In an embodiment of the present application, a positioning grid is arranged in the outer flow channel tube for maintaining the spacing between the sleeves.

[0018] The positioning grid is provided with a plurality of mounting holes, the inner wall of each mounting hole has a flow gap with the sleeve, and the inner wall of each mounting hole is provided with a positioning portion for positioning the sleeve.

[0019] In an embodiment of the present application, the outer flow channel tube is formed by splicing a plurality of sub-flow channel tubes.

[0020] In an embodiment of the present application, the positioning grid is arranged at the connection of two adjacent sub-flow channel tubes.

[0021] In an embodiment of the present application, the first shell and the second shell are connected by a pressure bearing pipe, the outer flow channel tube and the sleeve type heat exchanger are arranged in the pressure bearing pipe, and the pressure bearing pipe is sealingly arranged between the outer flow channel tube.

[0022] In an embodiment of the present application, at least one of the pressure shell, the first loop inlet, the second loop outlet, the first loop first outlet, the first loop second outlet, the second loop inlet and the pressure pipe is provided with a test interface for installation measurement of the measurement assembly.

[0023] In an embodiment of the present application, the external flow channel pipe is a light pipe or a support pipe with a concave structure arranged in an annular manner on the inner wall.

[0024] In an embodiment of the present application, the first shell and the second shell are formed by detachable splicing of at least two parts.

[0025] In an embodiment of the present application, the tube holes of the tube sheet assembly include multiple aperture specifications, and the tube holes with different aperture specifications are arranged in a concentric circular array on the first tube sheet and / or the second tube sheet.

[0026] In an embodiment of the present application, the test device for the double-pipe heat exchanger further includes a tube box support frame, the tube box support frame is arranged between the first shell and the second loop outlet water tube box, the tube box support frame is provided with a water inlet hole, the water inlet hole is connected with the inner cavity of the first shell and the flow channel between the outer sleeve pipe and the external flow channel pipe.

[0027] The present application provides a test method for a double-pipe heat exchanger, which is tested by the test device for the double-pipe heat exchanger, and the test method includes the following steps:

[0028] The double-pipe heat exchanger is installed with the test device for the double-pipe heat exchanger.

[0029] The measurement assembly for measuring the temperature and / or pressure of the fluid in the inner cavity of the first shell, the second loop outlet, the first loop first outlet, the first loop second outlet and the second loop inlet is installed.

[0030] The first fluid is introduced into the first loop inlet, and the second fluid is introduced into the second loop inlet.

[0031] The data measured by each measurement assembly is recorded.

[0032] The present application has the following beneficial effects: the test device for the double-pipe heat exchanger allows repeated use of the main structure and / or design scheme of the test device, such as replacing only the external flow channel pipe and / or the tube sheet assembly to adapt to double-pipe heat exchangers of different specifications, forming a standardized test platform; the flow resistance distribution and heat transfer characteristics of the real equipment can be simulated under the condition of scaling, and the test data can be directly extrapolated to the performance of the full-size equipment. The multi-parameter synchronous acquisition of the measurement assembly can verify the thermal design parameters of the double-pipe heat exchanger, such as the heat transfer coefficient and the resistance coefficient, and by adjusting the number of heat exchange tubes, the scaling test requirements of different powers can be met. BRIEF DESCRIPTION OF DRAWINGS

[0033] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. It is obvious that the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0034] In the attached diagram:

[0035] Figure 1 This is a schematic diagram of fluid flow in a shell-and-tube heat exchanger in the prior art, where A1 and A2 are generally the same medium used to heat or cool medium B.

[0036] Figure 2 This is a schematic diagram of the test device for a shell-and-tube heat exchanger provided in one embodiment of the present invention;

[0037] Figure 3 This is a schematic diagram of fluid flow within a test apparatus for a shell-and-tube heat exchanger provided in one embodiment of the present invention.

[0038] Figure 4 This is a schematic diagram of the arrangement of measuring components in a shell-and-tube heat exchanger test device provided in one embodiment of the present invention;

[0039] Figure 5 yes Figure 4 A schematic diagram of the AA structure;

[0040] Figure 6 yes Figure 4 BB structure diagram;

[0041] Figure 7 yes Figure 6 A partial structural diagram;

[0042] Figure 8 yes Figure 4 A schematic diagram of the CC structure;

[0043] Figure 9 This is a schematic diagram showing the connection between one end of the shell-and-tube heat exchanger and the tube sheet assembly and the secondary loop outlet water box.

[0044] The reference signs are as follows: double-pipe heat exchanger 100, outer sleeve 102, inner sleeve 101, pressure-containing shell 10, first shell 11, second shell 12, test interface 13, blowdown port 14, mounting bracket 15, primary loop inlet 111, secondary loop outlet 112, secondary loop inlet 121, primary loop first outlet 122, primary loop second outlet 123, external flow channel pipe 20, tube sheet assembly 30, first tube sheet 31, second tube sheet 32, measuring assembly 40, tube box assembly 50, secondary loop outlet water tube box 51, primary loop first outlet water tube box 52, primary loop second outlet water tube box 53, secondary loop inlet water tube box 54, tube box support bracket 55, pressure dividing device 60, liquid outlet hole 61, positioning grid 70, mounting hole 71, positioning part 72, pressure-containing pipe 80, sealing ring 81. DETAILED DESCRIPTION

[0045] The advantages and effects of the present application can be easily understood by those skilled in the art from the content disclosed in the specification. The present application can also be implemented or applied by different specific embodiments, and the details in the specification can be modified or changed based on different views and applications without departing from the spirit of the present application. The following embodiments and features in the embodiments can be combined with each other without conflict.

[0046] It should be noted that the drawings provided in the following embodiments only schematically illustrate the basic concept of the present application, and the drawings only show the components related to the present application, not the number, shape and size of the components when actually implemented. The shapes, numbers and proportions of the components when actually implemented can be randomly changed, and the layout pattern of the components can be more complex.

[0047] In the following description, a large number of details are discussed to provide a more thorough explanation of the embodiments of the present application, however, it is obvious to those skilled in the art that the embodiments of the present application can be implemented without these specific details, and in other embodiments, the known structures and devices are shown in the form of block diagrams instead of details to avoid making the embodiments of the present application difficult to understand.

[0048] The double-pipe heat exchanger 100 is a concentric double pipe connected by two pipes with different sizes, like Figure 1As shown, the outer one is the outer sleeve 102, and the inner one is the inner sleeve 101, and two different media can flow in the outer sleeve 102 and the inner sleeve 101 in opposite directions (or in the same direction) to achieve the effect of heat exchange. In this case, one inner sleeve 101 and one outer sleeve 102 arranged concentrically are defined as a sleeve heat exchanger 100, so as to facilitate the understanding of subsequent schemes. It should be understood that in real life, one inner sleeve 101 and one outer sleeve 102 arranged concentrically are a group, and generally one sleeve heat exchanger 100 includes one group or multiple groups arranged side by side. As shown in the figure, Figure 1 As shown, heat transfer is achieved by the countercurrent flow of two fluids between the inner and outer tubes. Generally, in the sleeve heat exchanger 100, the fluid A1 in the inner sleeve 101 and the fluid A2 outside the outer sleeve 102 are the same side fluid, and the fluid B between the inner and outer sleeves is the other side fluid. Due to the use of counterflow heat exchange, the sleeve heat exchanger 100 can achieve high heat exchange efficiency under relatively compact pipe arrangement structure, and is suitable for small flow, low flow rate, and narrow space with high heat exchange efficiency requirements.

[0049] The low-temperature heat supply reactor primary circuit adopts natural circulation, the flow rate is low, and the water quality is clean. In order to improve the safety of the reactor, the low-temperature heat supply reactor adopts an integrated arrangement, cancels the main pipeline, and adopts the method of embedding the heat exchanger in the reactor pressure vessel to lead out the heat of the primary circuit. Considering the space limitation inside the pressure vessel, the low-temperature heat supply reactor is very suitable for using a sleeve heat exchanger, but due to the lack of experience, it is necessary to use a thermal test to verify the heat exchange coefficient and resistance of the sleeve heat exchanger 100 and other important design parameters.

[0050] At present, there is no general structure form for the test verification of the sleeve heat exchanger 100 for reference. The test generally adopts the structure type of the test piece consistent with the product structure, and then the thermal hydraulic test is carried out through simple scaling according to the test conditions. This way generally has high cost of test equipment, long equipment manufacturing period, which leads to long research and development period and high research and development cost, which is not conducive to the popularization and utilization of the sleeve heat exchanger.

[0051] Based on the above considerations, the present application provides a simple sleeve heat exchanger test device, which can simulate the real heat exchange environment of the sleeve heat exchanger 100, and verify whether the heat exchange coefficient and resistance coefficient and other important design parameters of the heat exchanger meet the design requirements at a low cost, thereby helping the application and popularization of the sleeve heat exchanger 100 in important nuclear power systems.

[0052] As shown in the figure, Figure 1 The present application provides a sleeve heat exchanger test device, which comprises a pressure-containing shell 10, an external flow channel pipe 20, a tube plate assembly 30 and a measurement assembly 40;

[0053] The pressure-bearing housing 10 includes a first housing 11 and a second housing 12. The first housing 11 is provided with a first-loop inlet 111 and a second-loop outlet 112. The second housing 12 is provided with a second-loop inlet 121, a first-loop outlet 122 and / or a second-loop outlet 123.

[0054] The external flow channel 20 connects the two first shells 11 and the second shell 12, and is used to be sleeved on the outside of the fixed shell-and-tube heat exchanger 100.

[0055] like Figure 9 As shown, each of the two pressure-bearing shells 10 is provided with a set of tube sheet assemblies 30. Each set of tube sheet assemblies 30 includes a first tube sheet 31 for fixing the inner tube 101 of the shell-and-tube heat exchanger 100 and a second tube sheet 32 ​​for fixing the outer tube 102 of the shell-and-tube heat exchanger 100. The inner tube 101 is disposed inside the outer tube 102.

[0056] like Figure 4 As shown, the measuring component 40 includes a temperature measuring element and / or a pressure measuring element to measure the temperature and / or pressure at each loop inlet and / or the first housing 11 and / or the second housing 12;

[0057] like Figure 4 As shown, the primary loop inlet 111, the inner cavity of the first housing 11, the inner sleeve 101, and the primary loop first outlet 122 are connected in sequence; the primary loop inlet 111, the inner cavity of the first housing 11, the outer flow channel 20, and the corresponding primary loop first outlet 122 or primary loop second outlet 123 are connected in sequence; the secondary loop inlet 121, the outer sleeve 102, and the secondary loop outlet 112 are connected in sequence.

[0058] It should be noted that the pressure-bearing housing 10 includes a first housing 11 and a second housing 12. The first housing 11 is equipped with a primary loop inlet 111 and a secondary loop outlet 112. The second housing 12 is provided with a secondary loop inlet 121 and selectively configured with a primary loop first outlet 122 and / or a primary loop second outlet 123. This dual-outlet design allows the test device to adapt to different flow direction simulation requirements. The pressure-bearing housing 10 can be connected by flange bolts, welded sealing joints, or quick-release clamp structures to meet different pressure levels and maintenance requirements. The external flow channel pipe 20 connects the first housing 11 and the second housing 12, and is sleeved on the outside of the shell-and-tube heat exchanger 100 under test to form an equivalent flow channel. Its structure can be a straight-through metal rigid pipe, a combination of flexible hoses, or a segmented telescopic sleeve, ensuring accurate simulation of the actual equipment's external flow field morphology under scaled conditions.

[0059] The tube sheet assembly 30 is arranged in each shell, and each tube sheet assembly 30 includes a first tube sheet 31 and a second tube sheet 32. The first tube sheet 31 is used to fix the inner tube 101 of the double-pipe heat exchanger 100, and the second tube sheet 32 is used to fix the outer tube 102, forming a layered positioning structure. The assembly can be implemented by using a whole drilling plate, a split type clamping ring, or a modular quick-mounting clamp, wherein the layout of the inner tube 101 nested in the outer tube 102 can maintain the radial gap accuracy by using a coaxial positioning pin, a stepped clamping groove, or a hydraulic expansion sealing mechanism, or the radial gap accuracy can be maintained by the cooperation of the first tube sheet 31 and the second tube sheet 32. The measuring assembly 40 is integrated at the outlet of each loop, and includes independent or combined configurations of temperature measuring elements and pressure measuring elements.

[0060] As shown in Figure 4 , f1-f12 are the arrangement positions of the temperature measuring elements, and g1-g6 are the arrangement positions of the pressure measuring elements. The temperature measuring elements can be selected from armored thermocouples or optical fiber temperature measuring probes, and the pressure measuring elements can be selected from piezoresistive transducers, piezoelectric sensors, or mechanical pressure gauges, to realize the synchronous acquisition of multiple parameters. Among them, f1(f2) are two temperature measuring points at the inlet of the primary loop, f3 is a temperature measuring point at the outlet of the secondary loop; f4 is a first temperature measuring point in the dead water zone, f5 is a second temperature measuring point in the dead water zone, f6 is a third temperature measuring point in the dead water zone, f7(f8) are two temperature measuring points at the first outlet of the primary loop; f9(f10) are two temperature measuring points at the inlet of the secondary loop; f11(f12) are two temperature measuring points at the second outlet of the primary loop; g1 is a first pressure measuring point at the inlet of the primary loop; g2 is a second pressure measuring point at the inlet of the primary loop; g3 is a pressure measuring point at the first outlet of the primary loop; g4 is a pressure measuring point at the inlet of the secondary loop; g5 is a pressure measuring point at the second outlet of the primary loop; and g6 is a pressure measuring point at the outlet of the secondary loop.

[0061] The primary loop fluid enters the inner cavity of the first shell 11 from the primary loop inlet 111 thereof, and is divided into two paths: a first path flows to the primary loop first outlet 122 through the inner tube 101; and a second path flows to the primary loop first outlet 122 or the standby primary loop second outlet 123 of the second shell 12 through the flow channel between the external flow channel pipe 20 and the outer tube 102. The double-path design can be controlled by valve switching, and can accurately reproduce the distribution characteristics of the fluid in the shell side and the tube side in the actual device. The secondary loop fluid is introduced from the secondary loop inlet 121 of the second shell 12, flows through the flow channel between the outer tube 102 and the inner tube 101, and is then discharged from the secondary loop outlet 112 of the first shell 11. This reverse flow layout maintains the same or proportional average temperature difference as the actual device under the condition of scaling, and ensures the equivalence of the heat transfer characteristics. The channel formed by the external flow channel pipe 20 replaces the real device shell, so that the test piece does not need to be copied as a whole to simulate the shell side flow resistance and heat exchange boundary conditions of the double-pipe heat exchanger 100.

[0062] The conventional test of the double-pipe heat exchanger 100 relies on a 1:1 physical prototype, which has defects such as high research and development cost, long manufacturing cycle, and non-reusable test platform. The device breaks through the limitation of a single test piece corresponding to a single product specification by combining the pressure-containing shell 10 and the replaceable external flow channel pipe 20, and constructs a reconfigurable fluid path system: by switching the activation state of the first / second outlet, cooperating with the size adjustment of the tube sheet assembly 30 or the external flow channel pipe 20, the double-pipe heat exchanger 100 with different pipe diameters, lengths and arrangement forms can be quickly adapted on the unified test bench. The layered fixing structure of the tube sheet assembly 30 can solve the positioning accuracy problem of the inner sleeve pipe 101 and the outer sleeve pipe 102 in the scaled-down model, and avoid the distortion of the flow channel form caused by size reduction.

[0063] The device significantly reduces the test verification cost and cycle, and allows the reuse of the test bench main structure and / or design scheme, such as adapting different specifications of double-pipe heat exchangers 100 by only replacing the external flow channel pipe 20 and / or the tube sheet assembly 30, forming a standardized test platform. The double-outlet configuration and the adjustable flow channel structure accurately simulate the flow resistance distribution and heat transfer characteristics of the real equipment under the scaled-down condition, and the test data can be directly extrapolated to the full-size equipment performance. The multi-parameter synchronous acquisition of the measurement assembly 40 can verify the important design parameters such as the heat transfer coefficient and resistance of the double-pipe heat exchanger 100; the device greatly simplifies the maintenance process through modular construction, thereby improving the test efficiency.

[0064] The device can realize equivalent scaled-down simulation of thermal-hydraulic characteristics. The external flow channel pipe 20 accurately reproduces the shell side flow channel cross section ratio, and the stepped fixing of the tube sheet assembly 30 maintains the geometric similarity of the sleeve gap, ensuring that the real working process of the double-pipe heat exchanger 100 can be simulated to the greatest extent. The modular characteristics of the pressure-containing shell 10 allow the test bench to be expanded into a parallel test system for multiple double-pipe heat exchangers 100, providing a verification basis for the array of compact double-pipe heat exchangers 100 in the integrated arrangement of nuclear reactors.

[0065] As shown in Figure 1 and 9 As an optional embodiment of the present case, the external flow channel pipe 20 is sleeved with at least two groups of double-pipe heat exchangers 100.

[0066] It should be noted that a plurality of groups of test samples are integrated by a single flow channel space. The design adopts axial parallel arrangement and radial ring array to realize spatial multiplexing, wherein the axial parallel arrangement can fix the sleeve heat exchanger group through the segmented support frame, and the radial ring array can be distributed at equal intervals relying on the star-shaped support. The introduction of the plurality of groups of sleeve heat exchangers 100 enables the test device to have parallel test capability, and the shared annular channel formed by the external flow channel pipe 20 simulates the shell side boundary condition uniformly. The fluid forms an overall flow characteristic in the shared flow channel, and the isolation design of the tube plate assembly 30 ensures the independent metering of the tube side fluid of each sleeve heat exchanger 100, so as to simultaneously obtain a plurality of groups of performance data in a single test.

[0067] The conventional test device can only test a single piece, which is low in efficiency and cannot simulate the mutual influence of the array of sleeve heat exchangers 100. The present scheme breaks through the bottleneck of single sample testing through the integrated design of a plurality of groups of sleeve heat exchangers 100, and significantly improves the efficiency of test data acquisition. The parallel test mode reproduces the actual working condition of the compactly arranged group of sleeve heat exchangers 100 in the nuclear energy system, and the shared flow channel structure realizes the flow field interference effect between multiple devices, thereby providing key data for the array arrangement flow-induced vibration analysis. The modular arrangement structure allows flexible configuration of the number of test samples, the utilization rate of the test bench is improved by more than twice, and the verification cost of a unit test sample is greatly reduced.

[0068] As shown in Figure 1 and 9 As an optional embodiment of the present case, the sleeve heat exchanger test device further comprises a tube box assembly 50, the tube box assembly 50 comprises a secondary circuit outlet water pipe box 51 arranged in the first shell 11, and a primary circuit first outlet water pipe box 52 and a primary circuit second outlet water pipe box 53 arranged in the second shell 12, and a secondary circuit inlet water pipe box 54;

[0069] As shown in Figure 3 The primary circuit inlet 111, the inner cavity of the first shell 11, the inner sleeve 101, the primary circuit first outlet water pipe box 52 and the primary circuit first outlet 122 are sequentially communicated; the primary circuit inlet 111, the inner cavity of the first shell 11, the external flow channel pipe 20, the primary circuit second outlet water pipe box 53 and the primary circuit second outlet 123 are sequentially communicated;

[0070] The secondary circuit inlet 121, the secondary circuit inlet water pipe box 54, the outer sleeve 102, the secondary circuit outlet water pipe box 51 and the secondary circuit outlet 112 are sequentially communicated.

[0071] It should be noted that the tube box structure can be implemented using three basic methods: integral casting, separate welding, or modular assembly. After the primary loop fluid is split within the shell cavity, it is independently guided to the corresponding tube box via the inner sleeve 101 path and the outer flow channel 20 path. For example, one end of the multiple inner sleeves 101 of the multi-set shell-and-tube heat exchanger 100 is connected to the inner cavity of the first housing, and the other end is connected to the primary loop first outlet water tube box 52 inside the second housing 12; one end of the multiple outer sleeves 102 of the multi-set shell-and-tube heat exchanger 100 is connected to the secondary loop outlet water tube box 51 of the first housing, and the other end is connected to the secondary loop inlet water tube box 54 inside the second housing 12. The inner sleeve 101 sequentially connects to the primary loop inlet 111, the inner cavity of the casing, the inner sleeve 101, the first primary loop outlet pipe box 52, and finally to the first primary loop outlet 122. The outer flow channel pipe 20 leads to the second primary loop outlet pipe box 53 and exits from the second primary loop outlet 123. The secondary loop fluid is distributed to the outer sleeve 102 through the secondary loop inlet pipe box 54, collects in the secondary loop outlet pipe box 51, and then flows out from the secondary loop outlet 112. The hierarchical design of the pipe box system achieves strict isolation between the two loops, eliminating thermal interference during the test.

[0072] This solution eliminates the measurement crosstalk problem caused by flow channel intersections in traditional testing apparatuses. It constructs physically isolated fluid channels through a dedicated tubing system, ensuring independent metering accuracy for each loop medium. The dual single-loop outlet configuration expands the adjustable range of flow rates on both the shell and tube sides, accurately simulating flow fluctuations under natural circulation conditions. The modular tubing structure allows for rapid replacement of flow channel components, shortening test condition switching time. The layered sealing design meets nuclear-grade pressure requirements, achieving zero cross-contamination between radioactive and non-radioactive media.

[0073] like Figure 9 As shown, in an optional embodiment of this case, the first tube sheet 31 inside the first housing 11 is disposed at one end of the secondary loop outlet water pipe box 51 away from the shell-and-tube heat exchanger 100; the second tube sheet 32 ​​inside the first housing 11 is disposed at the other end of the secondary loop outlet water pipe box 51.

[0074] The first tube sheet 31 inside the second housing 12 is disposed between the first outlet pipe box 52 of the primary circuit and the inlet pipe box 54 of the secondary circuit; the second tube sheet 32 ​​inside the second housing 12 is disposed between the inlet pipe box 54 of the secondary circuit and the second outlet pipe box 53 of the primary circuit.

[0075] It should be noted that the tube plate positioning mode includes flange clamping type, threaded locking type, interference fit or hydraulic jacking type. Generally, the inner sleeve 101 of the sleeve heat exchanger 100 is longer than the outer sleeve 102, the outer diameter of the inner sleeve 101 is matched with the tube hole on the first tube plate 31, the outer diameter of the outer sleeve 102 is matched with the second tube plate 32, and the first tube plate 31 in the first shell 11 can be used to block one end of the two-loop outlet water pipe box 51 away from the sleeve heat exchanger 100, and the second tube plate 32 in the first shell 11 can be used to block the other end of the two-loop outlet water pipe box 51;

[0076] The first tube plate 31 in the second shell 12 can be used to block the one-loop first outlet water pipe box 52 and the two-loop inlet water pipe box 54 close to one end, and the second tube plate 32 in the second shell 12 can be used to block the two-loop inlet water pipe box 54 and the one-loop second outlet water pipe box 53 close to one end. The tube plate assembly 30 is used to seal the end of the pipe box assembly 50, thereby reducing the amount of material used, facilitating cost reduction and structural complexity.

[0077] As shown in Figure 1 As an optional embodiment of the present case, a pressure dividing device 60 is arranged in the first shell 11, the pressure dividing device 60 communicates the one-loop inlet 111 and the inner cavity of the first shell 11, and the pressure dividing device 60 is provided with a non-aligned liquid outlet hole 61 which is not aligned with the sleeve heat exchanger 100.

[0078] It should be noted that the pressure dividing device 60 is generally a container which is in a blocking state towards the sleeve heat exchanger 100, and the other direction of the container is provided with a liquid outlet hole 61. The non-aligned liquid outlet hole 61 is, for example, an eccentric distribution, a spiral array or a radial scattering embodiment, and in the present case, the axial direction of the liquid outlet hole 61 can be perpendicular or at an angle to the axial direction of the inner sleeve 101 and the outer sleeve 102 of the sleeve heat exchanger 100. The pressure dividing device 60 changes the initial kinetic energy distribution of the fluid entering the shell cavity, and the non-aligned layout of the liquid outlet hole 61 and the sleeve heat exchanger 100 forces the fluid to be premixed in the shell cavity, reduces the local high-speed flow directly impacting the heat exchange tube bundle, and makes the flow field distribution closer to the steady state working condition of the full-size equipment.

[0079] The present scheme reconstructs the inlet flow field through the pressure dividing device 60 to solve the problem of uneven fluid distribution under small flow conditions. The non-aligned liquid outlet hole 61 design destroys the axisymmetric flow pattern, effectively suppresses the central high-speed jet phenomenon unique to the scaled model, and makes the shell side flow velocity distribution keep dynamic similarity with the full-size equipment. The premixing cavity structure reduces the turbulence intensity, avoids the interference of local vortex flow to temperature measurement, and reduces the measurement error of heat transfer coefficient. The device also has the function of buffering pulsating pressure, providing a basis for natural circulation condition simulation.

[0080] As Figure 4 , 6 As shown in Fig. 7, as an optional embodiment of the present application, a positioning grid 70 for maintaining the spacing between each outer sleeve 102 is arranged in or adjacent to the outer flow channel pipe 20.

[0081] The positioning grid 70 is provided with a plurality of mounting holes 71, and the inner wall of each mounting hole 71 has a flow gap with the outer sleeve 102. The inner wall of each mounting hole 71 is provided with a positioning portion 72 protruding for positioning the outer sleeve 102.

[0082] It should be noted that the positioning grid 70 arranged in the outer flow channel pipe 20 is used to maintain the constant spacing between each outer sleeve 102, and its structural form includes three types of embodiments: cross-shaped support frame, honeycomb grid plate, and star-shaped radial frame. The cross-shaped support frame forms a positioning unit through orthogonal ribs, the honeycomb grid plate fixes the outer sleeve 102 group with a hexagonal hole array, and the star-shaped radial frame realizes circumferential positioning relying on the center hub and radial cantilever. The positioning portion 72 protruding from the inner wall of the mounting hole 71 of the positioning grid 70 is, for example, engaged by two symmetrically arranged middle concave protruding blocks or positioned by three or more uniformly distributed protrusions. For example, the flow gap between the mounting hole 71 and the outer sleeve 102 is designed to be 5%-50% of the pipe diameter, so that the fluid in the outer flow channel pipe 20 can smoothly pass through the surface of the outer sleeve 102 for heat exchange purpose. The present application provides radial constraint through the positioning portion 72, so that the position of the multiple groups of sleeve type heat exchangers 100 is stable and uniform, thereby ensuring the accuracy of the test.

[0083] As Figure 7 As shown in Fig. 7, as an optional embodiment of the present application, the positioning portion 72 and the outer sleeve 102 are in point contact or line contact or in surface contact with small area.

[0084] As an optional embodiment of the present application, the outer flow channel pipe 20 is formed by splicing a plurality of sub-flow channel pipes.

[0085] It should be noted that the splicing connection mode of the plurality of sub-flow channel pipes includes threaded sleeve locking or welding connection mode. Since the outer flow channel pipe 20 is spliced, it can be prefabricated to reduce the production and manufacturing time. A streamlined flow guide ring can be arranged at the interface of each sub-flow channel pipe to eliminate step mutation, maintain the hydraulic diameter consistency of the overall flow channel, and ensure that the friction resistance coefficient along the path under the scaling condition strictly corresponds to the full-size device. Since the fixed-length flow channel pipe cannot adapt to different specifications of the sleeve type heat exchanger 100, the present application realizes stepless adjustment of the flow channel length through the combination of the detachable sub-flow channel pipes, completely avoiding the overall test piece from being scrapped due to the size change of the sleeve type heat exchanger 100. The quick-mounting interface design greatly shortens the flow channel reconstruction time and shortens the test preparation period.

[0086] As an optional embodiment of the present case, the positioning grid 70 is arranged at the connection of two adjacent sub-flow channel pipes.

[0087] It should be noted that in the present case, the end of the two adjacent sub-flow channel pipes close to each other can be connected with the positioning grid 70, so that the positioning grid 70 has the function of connecting the adjacent two sub-flow channel pipes in addition to the supporting function of the external flow channel pipe 20 and the positioning function of each group of tube heat exchanger 100, for example, the outer wall of the positioning grid 70 is interference fit or bonded with the inner wall of the adjacent two sub-flow channel pipes by high-temperature resistant glue. Installing the positioning grid 70 at the connection of the two adjacent sub-flow channel pipes reduces the difficulty of installing the positioning grid 70, thereby reducing the installation cost and improving the installation efficiency.

[0088] As shown in Figure 1 As an optional embodiment of the present case, the first shell 11 and the second shell 12 are connected by a pressure-bearing pipe 80, the external flow channel pipe 20 and the tube heat exchanger 100 are arranged in the pressure-bearing pipe 80, and the pressure-bearing pipe 80 is sealingly arranged with the external flow channel pipe 20.

[0089] It should be noted that the connection mode of the pressure-bearing pipe 80 includes flange bolt sealing, sleeve type locking, welding connection or interference fit connection. The sealing arrangement between the pressure-bearing pipe 80 and the external flow channel pipe 20 is achieved in the form of annular packing block, hydraulic sealing ring, or welded isolation chamber or other sealing ring 81. Generally, there is a gap between the pressure-bearing pipe 80 and the external flow channel pipe 20, so as to facilitate the size adjustment of the external flow channel pipe 20 without adjusting the size of the pressure-bearing pipe 80. The pressure-bearing pipe 80 as a primary pressure boundary bears the system load, and the external flow channel pipe 20 maintains the precise flow channel shape; through the arrangement of the pressure-bearing pipe 80, the gravity of the components and fluid inside the pressure-bearing pipe 80, such as the external flow channel pipe 20 and the tube heat exchanger 100, can be better borne; the present scheme further improves the leakage risk control level through the containment design of the pressure-bearing pipe 80, and further increases the accuracy of the boundary conditions of temperature measurement, thereby improving the accuracy of the test.

[0090] As shown in Figure 1 and 5 As an optional embodiment of the present case, at least one of the pressure-bearing shell 10, the one-way loop inlet 111, the two-way loop outlet 112, the one-way loop first outlet 122, the one-way loop second outlet 123, the two-way loop inlet 121 and the pressure-bearing pipe 80 is provided with a test interface 13, and the test interface 13 is used for the installation and measurement of the measurement assembly 40.

[0091] It should be noted that the interfaces of the pressure shell 10 and the pressure pipe 80 are provided with test interfaces 13, which include embodiments such as standard threaded interfaces, flange adapters, and welded measurement bases. The standard threaded interfaces are suitable for direct insertion installation of armored sensors, the flange adapters integrate multi-channel penetrations, and the welded measurement bases provide non-destructive testing coupling surfaces. By constructing a distributed measurement network, the inlet 111 and outlet interfaces of the primary circuit monitor thermal imbalance, the interfaces of the pressure pipe 80 capture the temperature gradient along the pipeline, and the interfaces of the secondary circuit record dynamic pressure drop spectra. The present case covers the whole process through the test interfaces 13, realizes the stereoscopic evaluation of the performance of the double-pipe heat exchanger 100, and provides spatial resolution data for optimized design. Standardized interfaces reduce the time-consuming installation of sensors and improve the efficiency of test data acquisition.

[0092] As shown in Figure 8 As an optional embodiment of the present case, the outer flow channel pipe 20 is a light pipe or a support pipe with a concave structure arranged annularly on the inner wall.

[0093] It should be noted that the outer flow channel pipe 20 is a light pipe or a support pipe with a concave structure arranged annularly on the inner wall. The concave structure includes configurations such as axial grooves or hemispherical pits. The axial grooves parallel to the fluid direction reduce frictional resistance, and the hemispherical pits achieve drag reduction and stability enhancement through boundary layer separation control. The present case manufactures two double-pipe heat exchanger test devices, and the outer flow channel pipes 20 of the two double-pipe heat exchanger test devices are respectively a light pipe or a support pipe with a concave structure arranged annularly on the inner wall, and other structures remain the same. Since the outer flow channel pipe 20 provides two different external boundary environments, it is beneficial to improve the accuracy of test simulation.

[0094] As an optional embodiment of the present case, the first shell 11 and the second shell 12 are each formed by at least two detachable parts.

[0095] It should be noted that the first shell 11 and the second shell 12 are each formed by at least two detachable parts, and the connection methods include embodiments such as axial or radial split flange connection, hinge lock mechanism, and modular clamping assembly. The split flange realizes pressure sealing through a V-shaped sealing ring 81 and segmented compression bolts, the hinge lock mechanism uses an eccentric cam to compress the split surface, and the modular clamping assembly uses a tapered self-locking pin to complete rapid assembly. The technical principle of this detachable design is to reconstruct the internal chamber through the split interface, the split surface is arranged in a stress-free concentration area, and a special sealing structure is used to maintain the integrity under high pressure conditions.

[0096] The traditional integral shell causes the sleeve heat exchanger 100 to be difficult to maintain, and the detachable pressure shell 10 structure realizes convenient maintenance and replacement of the internal components of the test device. The split design shortens the replacement time of the tube sheet assembly 30, greatly improving the test iteration efficiency. The modular clamping mechanism allows a single person to operate the shell opening and closing, reducing operation and maintenance costs. The segmented flange sealing reliability meets the pressure requirements of nuclear-level equipment, has a low leakage rate, and ensures the safety of radioactive medium testing.

[0097] As an optional embodiment of the present case, the tube sheet assembly 30 includes a first tube sheet 31 and / or a second tube sheet 32 with multiple aperture specifications, and the tube holes are arranged in a concentric circle array on the first tube sheet 31 and / or the second tube sheet 32. The same tube sheet corresponds to an inner sleeve 101 and an outer sleeve 102 of one size. The present case provides a tube sheet assembly 30 with different specifications to facilitate the installation of sleeve heat exchangers 100 of multiple specifications. It should be understood that the tube hole size of the tube sheet assembly 30 only needs to be designed according to the inner sleeve 101, the outer sleeve 102, and the spacing of the adjacent sleeve heat exchanger 100. The design and manufacturing are relatively simple, and different sleeve heat exchangers 100 can be customized to meet actual use requirements.

[0098] As shown in Figure 1 As an optional embodiment of the present case, the sleeve heat exchanger test device further includes a tube box support frame 55 arranged between the first shell 11 and the second loop water outlet tube box 51. The tube box support frame 55 is provided with a water inlet hole, and the water inlet hole is in communication with the inner cavity of the first shell 11 and the flow channel between the outer sleeve 102 and the external flow channel pipe 20. By arranging the tube box support frame 55 and the water inlet hole, a separate tube box is not needed to enter the flow channel between the outer sleeve 102 and the external flow channel pipe 20, thereby reducing the structural complexity and material usage, and reducing the cost.

[0099] As an optional embodiment of the present case, the first loop first water outlet tube box 52 and the second loop first water outlet tube box 53 and the second loop water inlet tube box 54 are integrally formed with the second shell 12. The manufacturing process includes integral casting, forging forming or additive manufacturing, thereby improving the safety of use and avoiding or reducing the risk of interface leakage.

[0100] As shown in Figure 1 As an optional embodiment of the present case, the bottom of the second shell 12 is further provided with a blowdown port 14. During normal operation, the hydraulic self-sealing structure maintains a zero leakage state. During maintenance, the sediment is quickly discharged through the flange blind plate, and the gravity self-cleaning mechanism is relied on to prevent the retention of particulate matter.

[0101] By reasonably arranging measuring instruments on the test device and test loop of the double-pipe heat exchanger, the pressure, flow rate, temperature and other parameters under the conditions of no power platform and different flow rate distribution ratios of the primary side can be measured, and then it is verified whether the design of the double-pipe heat exchanger can meet the design requirements. At the splicing position of the outer flow channel pipe 20, the positioning grid 70 of the outer sleeve pipe 102 is arranged to ensure the gap between the outer sleeve pipes 102, and the number of the positioning grid 70 is reasonably set according to the length of the heat exchange pipe.

[0102] The mounting bracket 15 of the test device of the double-pipe heat exchanger is composed of a splicing structure, and the support plates are fastened by bolts. This design structure is beneficial to the transportation of the test device of the double-pipe heat exchanger and the installation of the test device of the double-pipe heat exchanger on the test bench.

[0103] The test device of the double-pipe heat exchanger can verify the thermal design parameters of the double-pipe heat exchanger, including the heat exchange coefficient and the resistance coefficient, by testing, and can meet the requirements of different power scale test by adjusting the number of the heat exchange pipes.

[0104] As an optional embodiment of the present application, the position of the tube sheet assembly 30 can be adjusted for different tests, the length of the inner and outer sleeve heat exchange pipes can be adjusted, the radial size of the inner and outer sleeve pipes can be adjusted, the number of the heat exchange pipes can be adjusted, the cross-sectional size and form of the outer flow channel pipe 20 can be adjusted, the number of the segmented outer flow channel pipe 20 and the number of the positioning grid 70 can be adjusted, so as to meet the requirements of different tests.

[0105] The present application provides a test method of a double-pipe heat exchanger, which is tested by the test device of the double-pipe heat exchanger, and the test method comprises the following steps:

[0106] S1: installing the double-pipe heat exchanger 100 and the test device of the double-pipe heat exchanger, which further comprises the steps of sleeving the outer flow channel pipe 20 on the outer side of the double-pipe heat exchanger 100, connecting the double-pipe heat exchanger 100 and the tube sheet assembly 30 of the test device of the double-pipe heat exchanger, and connecting the tube sheet assembly 30 and the pressure-bearing shell 10;

[0107] S2: installing the measuring assembly 40 for measuring the temperature and / or pressure of the fluid in the inner cavity of the first shell 11, the second loop outlet 112, the first loop first outlet 122, the second loop second outlet 123 and the second loop inlet 121;

[0108] S3: introducing the first fluid into the first loop inlet 111 and introducing the second fluid into the second loop inlet 121;

[0109] S4: recording the data measured by each measuring assembly 40.

[0110] It should be noted that the installation process adopts axial sliding into, radial module assembly, overall lifting, welding and other ways; the measurement assembly 40 configuration includes single-point, array distributed or wireless sensor network data acquisition mode; the present case uses the geometric similarity and thermal similarity criterion of the modular test device, and the use parameters of the actual equipment can be accurately reproduced through the 1:1 model or the scaled-down model. The array temperature measurement network captures the three-dimensional temperature field distribution, and records the dynamic coupling process of the thermal parameters of the shell side and the tube side through data acquisition. The test data can be directly extrapolated to the full-size equipment performance, and the research and development cycle is greatly reduced.

[0111] The above embodiments only illustrate the principles and effects of the present application, and are not used to limit the present application. Any person skilled in the art can modify or change the above embodiments without departing from the spirit and scope of the present application. Therefore, all equivalent modifications or changes made by those skilled in the art without departing from the spirit and technical idea disclosed by the present application should be covered by the claims of the present application.

Claims

1. A test device for a double-pipe heat exchanger, characterized by The application relates to a pressure-bearing shell, which comprises a first shell and a second shell, the first shell is provided with a primary loop inlet and a secondary loop outlet; the second shell is provided with a secondary loop inlet, a primary loop first outlet and / or a primary loop second outlet; an external flow channel pipe is arranged between the first shell and the second shell and is used for sleeving the outside of a fixed sleeve heat exchanger; a tube plate assembly is arranged in each of the two pressure-bearing shells, each tube plate assembly comprises a first tube plate for fixing an inner sleeve of the fixed sleeve heat exchanger and a second tube plate for fixing an outer sleeve of the fixed sleeve heat exchanger, and the inner sleeve is arranged in the outer sleeve; a measuring assembly is arranged in each of the two pressure-bearing shells, the measuring assembly comprises a temperature measuring element and / or a pressure measuring element and is used for measuring the temperature and / or pressure of each loop inlet and outlet; the primary loop inlet, the inner cavity of the first shell, the inner sleeve and the primary loop first outlet are sequentially communicated; the primary loop inlet, the inner cavity of the first shell, the external flow channel pipe and the corresponding primary loop first outlet or primary loop second outlet are sequentially communicated; the secondary loop inlet, the outer sleeve and the secondary loop outlet are sequentially communicated. The external flow channel pipe is sleeved with at least two groups of sleeve heat exchangers. The application further relates to a tube box assembly, which comprises a secondary loop outlet water tube box arranged in the first shell and a primary loop first outlet water tube box, a primary loop second outlet water tube box and a secondary loop inlet water tube box arranged in the second shell. The primary loop inlet, the inner cavity of the first shell, the inner sleeve, the primary loop first outlet water tube box and the primary loop first outlet are sequentially communicated; the primary loop inlet, the inner cavity of the first shell, the external flow channel pipe, the primary loop second outlet water tube box and the primary loop second outlet are sequentially communicated; the secondary loop inlet, the secondary loop inlet water tube box, the outer sleeve, the secondary loop outlet water tube box and the secondary loop outlet are sequentially communicated. The first tube plate arranged in the first shell is arranged at one end of the secondary loop outlet water tube box away from the sleeve heat exchanger; the second tube plate arranged in the first shell is arranged at the other end of the secondary loop outlet water tube box; the first tube plate arranged in the second shell is arranged between the primary loop first outlet water tube box and the secondary loop inlet water tube box; and the second tube plate arranged in the second shell is arranged between the secondary loop inlet water tube box and the primary loop second outlet water tube box. A pressure dividing device is arranged in the first shell and is communicated with the primary loop inlet and the inner cavity of the first shell, and the pressure dividing device is provided with a liquid outlet hole which is not aligned with the sleeve heat exchanger.

2. The shell-and-tube heat exchanger test device of claim 1, wherein, A positioning grid is arranged in the external flow channel pipe and is used for keeping the spacing between the outer sleeves.

3. The shell-and-tube heat exchanger test device of claim 1, wherein, The positioning grid is provided with a plurality of mounting holes, the inner wall of each mounting hole is provided with a positioning part which is used for positioning the outer sleeve and has a flow gap with the outer sleeve. The external flow channel pipe is formed by splicing a plurality of sub-flow channel pipes. The positioning grid is arranged at the connection position of two adjacent sub-flow channel pipes.

4. The shell-and-tube heat exchanger test device of claim 3, wherein, The first shell and the second shell are connected by a pressure-bearing pipe, the external flow channel pipe and the sleeve heat exchanger are arranged in the pressure-bearing pipe, and the pressure-bearing pipe is sealingly arranged between the external flow channel pipe and the sleeve heat exchanger. ​ 5. The shell-and-tube heat exchanger test device of claim 1, wherein, ​ 6. The double pipe heat exchanger testing device according to claim 1, wherein ​ ​ 7. The shell-and-tube heat exchanger test device of claim 6, wherein, ​ 8. The shell-and-tube heat exchanger test device of claim 7, wherein, ​ 9. The double-pipe heat exchanger test device according to claim 1, characterized by ​ 10. The shell-and-tube heat exchanger test device of claim 9, wherein, At least one of the pressure shell, the primary loop inlet, the secondary loop outlet, the primary loop first outlet, the primary loop second outlet, the secondary loop inlet and the pressure pipe is provided with a test interface for installation measurement of the measurement assembly.

11. The double pipe heat exchanger testing device according to claim 1, wherein The external flow channel pipe is a light pipe or a support pipe with a concave structure arranged in an annular manner on the inner wall.

12. The double pipe heat exchanger testing device of claim 1, wherein, The first shell and the second shell are formed by detachable splicing of at least two parts.

13. The double pipe heat exchanger testing device of claim 1, wherein, The tube holes of the tube sheet assembly include multiple aperture specifications, and the tube holes with different aperture specifications are arranged in a concentric circular array on the first tube sheet and / or the second tube sheet.

14. The double pipe heat exchanger testing device of claim 1, wherein, Further comprising a tube box support frame arranged between the first shell and the secondary loop outlet water tube box, the tube box support frame is provided with a water inlet hole, the water inlet hole is connected with the inner cavity of the first shell and the flow channel between the outer sleeve pipe and the external flow channel pipe.

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