Reactor coolant temperature measuring device

Abstract

The present invention relates to the technical field of nuclear power plant coolant temperature measurement, and in particular to a reactor coolant temperature measurement device, comprising: three reactor outlet temperature measurement assemblies and three reactor inlet temperature measurement assemblies, wherein the reactor outlet temperature measurement assemblies and the reactor inlet temperature measurement assemblies are respectively mounted on a pressure vessel top cover; the reactor outlet temperature and reactor inlet temperature measurement devices designed by the present invention are both non-drainage disassembly and assembly structures, and thermocouples are mounted via ferrule threads and do not directly contact a primary circuit high-temperature and high-pressure coolant; the reactor inlet temperature measurement device adopts a drainage structure to drain the reactor inlet coolant in the lower chamber of the pressure vessel to above the active section of the core, thereby preventing the thermocouple sensor from passing through the highly irradiated active section of the core.

Description

Technical Field

[0001] The present invention relates to the technical field of nuclear power plant coolant temperature measurement, in particular to a reactor coolant temperature measurement device. Background Art

[0002] Reactor coolant temperature is one of the most important parameters that characterize the operating status of a reactor. In common distributed reactors, the coolant temperature is usually measured on the main pipeline or in the temperature measurement bypass using a platinum resistance thermometer. Compact reactors usually connect the main pump and steam generator to the pressure vessel through short pipes or directly, so that the coolant temperature measurement can only be carried out inside the pressure vessel, which puts forward new requirements for the structure and layout of the temperature sensor. For the reactor inlet temperature, since the typical temperature measurement points are all in the lower chamber of the pressure vessel, inserting the thermometer into the lower chamber to measure the reactor inlet temperature will result in a very long thermometer, which has a great impact on the structural design of the thermometer. At the same time, the passage of the thermocouple through the highly irradiated core active area also has an additional impact on the temperature measurement.

[0003] Therefore, it is necessary to design a coolant temperature measuring device and a measuring method suitable for compactly arranged reactors to improve the deficiencies of the prior art. Summary of the Invention

[0004] The present invention designs a reactor coolant temperature measuring device, which is used to solve the technical problems that the existing reactor coolant temperature measurement points are all in the lower chamber of the pressure vessel. Inserting the thermometer into the lower chamber to measure the reactor inlet temperature will easily cause the thermometer to be too long. At the same time, the thermocouple passing through the highly irradiated core active area is also likely to have additional influence on the temperature measurement.

[0005] The technical solution of the present invention:

[0006] A reactor coolant temperature measuring device comprises: three reactor outlet temperature measuring assemblies and three reactor inlet temperature measuring assemblies, wherein the reactor outlet temperature measuring assemblies and the reactor inlet temperature measuring assemblies are respectively mounted on the pressure vessel top cover; the three reactor outlet temperature measuring assemblies are mounted on the pressure vessel top cover at intervals of 120° in pairs and are vertically inserted into the pressure vessel; the three reactor inlet temperature measuring assemblies 5 are also distributed on the pressure vessel top cover at intervals of 120° in pairs and are vertically inserted into the pressure vessel; and an angle of 15° is formed between adjacent reactor outlet temperature measuring assemblies and reactor inlet temperature measuring assemblies, wherein the angle of 15° is the angle between the center of the top cover on the circumferential plane of the top cover.

[0007] The reactor outlet temperature measurement assembly includes: a reactor outlet temperature measurement tube and a thermocouple thermometer; the reactor outlet temperature measurement tube is internally provided with a thermocouple thermometer;

[0008] The reactor outlet temperature measuring tube comprises: a reactor outlet temperature measuring tube installation section, a reactor outlet temperature measuring tube root section, a reactor outlet temperature measuring tube reduced diameter section, and a reactor outlet temperature measuring tube terminal section;

[0009] The top of the reactor outlet temperature measurement root section is the reactor outlet temperature measurement installation section; the bottom of the reactor outlet temperature measurement root section is the reactor outlet temperature measurement reduced diameter section; the bottom of the reactor outlet temperature measurement reduced diameter section is the reactor outlet temperature measurement terminal section; the reactor outlet temperature measurement root section, the reactor outlet temperature measurement reduced diameter section, and the reactor outlet temperature measurement terminal section are all hollow tubular structures, the inner diameter of the reactor outlet temperature measurement root section is larger than the inner diameter of the reactor outlet temperature measurement reduced diameter section, and the inner diameter of the reactor outlet temperature measurement reduced diameter section is larger than the inner diameter of the reactor outlet temperature measurement terminal section.

[0010] The thermocouple thermometer includes: a thermocouple thermometer installation section, a support tube, a thermocouple and a thermocouple reduction section; the top of the support tube is provided with the thermocouple thermometer installation section; the bottom of the support tube is a thermocouple, and the bottom of the thermocouple is provided with a thermocouple reduction section.

[0011] The reactor inlet temperature measurement assembly comprises: an inlet temperature measurement component and a flow diversion component; the inlet temperature measurement component is arranged inside the flow diversion component.

[0012] The drainage component comprises: a drainage component installation section, a drainage component root section, a drainage component reduced diameter section, eight water flow holes, a drainage component end section, four drainage holes, a cut-off component and an end plug;

[0013] The drainage component is a hollow structure as a whole, the top of the drainage component is the drainage component installation section, and below the drainage component installation section is the drainage component root section; below the drainage component root section is the drainage component reduced diameter section; below the drainage component reduced diameter section is the drainage component terminal section, and four drainage holes are arranged in a ring on the drainage component terminal section; a shut-off component is welded to the bottom of the drainage component terminal section; and an end plug is provided on the shut-off component.

[0014] Eight water flow holes are arranged in a ring on the reduced diameter section of the diversion component, and the opening direction of the water flow holes is inclined upward; the bottom position of the inlet temperature measuring component is at the reduced diameter section of the diversion component, that is, the coolant diverted from the lower part of the diversion component flows out through the eight water flow holes after flowing through the end of the inlet temperature measuring component.

[0015] The shut-off component is a bowl-shaped structure as a whole, and an end plug is provided at the center of the shut-off component;

[0016] The coolant is collected by the intercepting component, passes through the drainage guide of the end plug, turns downward, passes through the drainage hole, and flows vertically upward into the interior of the drainage component.

[0017] The upper part of the end plug is a conical structure, which is conducive to changing the direction of fluid flow; the lower part of the end plug is a tapered bullet-shaped structure to prevent the water flow from forming turbulence.

[0018] Beneficial effects of the present invention:

[0019] The reactor outlet and inlet temperature measurement components designed by the present invention are arranged on the periphery of the pressure vessel top cover and vertically inserted into the pressure vessel, which can realize three-way reactor outlet temperature and three-way reactor inlet temperature measurement. The thermometer is easy to install and does not affect other equipment on the reactor top.

[0020] The reactor outlet and inlet temperature measurements designed in the present invention are both non-drainage and disassembly structures. The thermocouples are installed through ferrule threads and do not directly contact the primary circuit high-temperature, high-pressure coolant. The reactor inlet temperature measurement uses a drainage structure to divert the reactor inlet coolant from the lower chamber of the pressure vessel to above the core active section, preventing the thermocouple sensor from passing through the highly irradiated core active section.

[0021] The reactor inlet temperature measurement system employs a "large inlet, small outlet" design, increasing the coolant's flow rate upon entry and ensuring it reaches the temperature measurement structure. At the temperature measurement structure, the enlarged inner diameter of the structure reduces the fluid velocity, thereby mitigating the impact of the water on the structure. Upward-facing water holes are provided on the wall of the structure near the temperature measurement structure to promptly drain coolant out of the structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A front view of the reactor coolant temperature measuring device designed for the present invention installed on a pressure vessel;

[0023] Figure 2 A top view of the reactor coolant temperature measuring device of the present invention installed on a pressure vessel;

[0024] Figure 3 This is a schematic diagram of the reactor outlet temperature measurement assembly of the present invention being arranged on a pressure vessel top cover pipe seat;

[0025] Figure 4 This is a schematic structural diagram of the thermocouple thermometer described in the present invention;

[0026] Figure 5 This is a schematic structural diagram of the drainage device according to the present invention;

[0027] Figure 6 This is a schematic diagram of the installation of the reactor inlet temperature measurement assembly of the present invention on the top cover pipe seat of a pressure vessel.

[0028] Among them: 1-main pump, 2-steam generator, 3-pressure vessel, 4-reactor outlet temperature measurement assembly, 411-reactor outlet temperature measurement tube, 41-reactor outlet temperature measurement tube installation section, 42-reactor outlet temperature measurement tube root section, 43-reactor outlet temperature measurement reduced diameter section, 44-reactor outlet temperature measurement terminal section,

[0029] 5-reactor inlet temperature measurement assembly, 6-hexagonal, 7-thermocouple thermometer, 71-thermocouple thermometer installation section, 72-support tube, 73-thermocouple, 74-thermocouple reduced diameter section, 9-inlet temperature measurement component, 10-drainage component, 101-drainage component installation section, 102-drainage component root section, 103-drainage component reduced diameter section, 104-water flow hole, 105-drainage component end section, 106-drainage hole, 107-cut-off component, 108-end plug DETAILED DESCRIPTION

[0030] A reactor coolant temperature measuring device of the present invention will be described in detail below with reference to the accompanying drawings and embodiments.

[0031] A reactor coolant temperature measuring device comprises: three reactor outlet temperature measuring assemblies 4 and three reactor inlet temperature measuring assemblies 5, wherein the reactor outlet temperature measuring assemblies 4 and the reactor inlet temperature measuring assemblies 5 are respectively mounted on the top cover of a pressure vessel; the three reactor outlet temperature measuring assemblies 4 are mounted on the top cover of the pressure vessel at intervals of 120 degrees in pairs and are vertically inserted into the pressure vessel; the three reactor inlet temperature measuring assemblies 5 are also distributed on the top cover of the pressure vessel at intervals of 120 degrees in pairs and are vertically inserted into the pressure vessel, and there is a 15-degree angle between adjacent reactor outlet temperature measuring assemblies and reactor inlet temperature measuring assemblies; the 15-degree angle is the angle between the center of the top cover on the circumferential plane of the top cover.

[0032] The reactor outlet temperature measurement assembly 4 includes: a reactor outlet temperature measurement tube 411 and a thermocouple thermometer 7; the reactor outlet temperature measurement tube 411 is provided with a thermocouple thermometer 7;

[0033] The top of the reactor outlet temperature measurement assembly 4 is fixed to the pressure vessel top cover pipe seat through a hexagonal 6-thread;

[0034] The top of the reactor inlet temperature measurement assembly 5 is fixed to the pressure vessel top cover pipe seat through a hexagonal 6 thread;

[0035] The reactor outlet temperature measuring tube 411 includes: a reactor outlet temperature measuring tube installation section 41, a reactor outlet temperature measuring tube root section 42, a reactor outlet temperature measuring tube reduced diameter section 43, and a reactor outlet temperature measuring tube terminal section 44;

[0036] The top of the reactor outlet temperature measurement root section 42 is the reactor outlet temperature measurement installation section 41; the bottom of the reactor outlet temperature measurement root section 42 is the reactor outlet temperature measurement reduced diameter section 43; the bottom of the reactor outlet temperature measurement reduced diameter section 43 is the reactor outlet temperature measurement terminal section 44; the reactor outlet temperature measurement root section 42, the reactor outlet temperature measurement reduced diameter section 43, and the reactor outlet temperature measurement terminal section 44 are all hollow tubular structures, the inner diameter of the reactor outlet temperature measurement root section 42 is larger than the inner diameter of the reactor outlet temperature measurement reduced diameter section 43, and the inner diameter of the reactor outlet temperature measurement reduced diameter section 43 is larger than the inner diameter of the reactor outlet temperature measurement terminal section 44.

[0037] The thermocouple thermometer 7 includes: a thermocouple thermometer installation section 71, a support tube 72, a thermocouple 73 and a thermocouple reduction section 74; the top of the support tube 72 is provided with the thermocouple thermometer installation section 71; the bottom of the support tube 72 is the thermocouple 73, and the bottom of the thermocouple 73 is provided with a thermocouple reduction section 74.

[0038] The reactor inlet temperature measurement assembly 5 includes: an inlet temperature measurement component 9 and a flow guide component 10 ; the inlet temperature measurement component 9 is provided inside the flow guide component 10 .

[0039] The drainage component 10 includes: a drainage component installation section 101, a drainage component root section 102, a drainage component reduced diameter section 103, eight water flow holes 104, a drainage component end section 105, four drainage holes 106, a shut-off component 107 and an end plug 108;

[0040] The drainage component 10 is a hollow structure as a whole. The top of the drainage component 10 is the drainage component installation section 101, and below the drainage component installation section 101 is the drainage component root section 102; below the drainage component root section 102 is the drainage component reduced diameter section 103; below the drainage component reduced diameter section 103 is the drainage component terminal section 105, and four drainage holes 106 are arranged in a ring on the drainage component terminal section 105; a shut-off component 107 is welded to the bottom of the drainage component terminal section 105; and an end plug 108 is provided on the shut-off component 107.

[0041] Eight water flow holes 104 are arranged in a ring on the reduced diameter section 103 of the diversion component, and the opening direction of the water flow holes 104 is inclined upward; the bottom position of the inlet temperature measuring component 9 is at the reduced diameter section 103 of the diversion component 10, that is, the coolant diverted from the lower part of the diversion component 10 flows out through the eight water flow holes after flowing through the end of the inlet temperature measuring component 9.

[0042] The shut-off component 107 is a bowl-shaped structure as a whole, and an end plug 108 is provided at the center of the shut-off component 107;

[0043] The coolant is collected by the intercepting component 107 and then passes through the drainage guide of the end plug 108 , turns 90°, and flows vertically upward into the interior of the drainage component 10 through the drainage hole 106 .

[0044] The upper portion of the end plug 108 is a conical structure, which is conducive to changing the direction of fluid flow; the lower portion of the end plug 108 is a tapered bullet-shaped structure to prevent the water flow from forming turbulent flow.

[0045] Example

[0046] In this example, the reactor outlet temperature measuring tube mounting section 41 includes: component mounting threads and thermocouple mounting threads. The component mounting threads use M27×2 external threads, and the thermocouple mounting threads use M16×1.5 internal threads. The reactor outlet temperature measuring tube mounting section 41 is installed on the mounting pipe seat on the pressure vessel top cover through the M27×2 threads and is seal-welded.

[0047] In this example, the reactor outlet temperature measuring tube root section 42 has an outer diameter of Φ20 mm and an inner diameter of Φ10 mm.

[0048] In this example, the reactor outlet temperature measuring tube reduced diameter section 43 has an outer diameter of 10 mm and an inner diameter of 5 mm, and the reactor outlet temperature measuring tube terminal section 44 has an outer diameter of 6 mm and an inner diameter of 3.2 mm.

[0049] The thermocouple thermometer is installed in the reactor outlet temperature measuring tube 411 through the M16×1.5 external thread of the thermocouple thermometer installation section 71.

[0050] The thermocouple 73 is an armored structure with an outer diameter of Φ4 mm, and the outer diameter of the thermocouple reduced diameter section 74 is Φ3 mm.

[0051] A support tube 72 is provided outside the thermocouple to improve the rigidity of the thermocouple. The reactor outlet temperature measurement assembly 4 and the thermocouple both adopt a variable cross-section design, which not only ensures structural strength but also shortens response time. Figure 3 .

[0052] In this embodiment, the structure of the inlet temperature measurement component 9 is consistent with that of the reactor outlet temperature measurement assembly 4. This design allows the components of the two to be as universal as possible. The flow guide component 10 is installed on the pipe seat of the pressure vessel top cover through threads.

[0053] The flow guiding component 10 also adopts a segmented diameter reduction structure to adapt to the inlet temperature measurement structure.

[0054] In this embodiment, the root section 102 of the drainage component has an outer diameter of Φ36 mm and an inner diameter of Φ24 mm.

[0055] The outer diameter of the reduced diameter section 103 of the drainage component is Φ24mm and the inner diameter is 12mm.

[0056] In this embodiment, the reduced diameter section 103 of the drainage component is provided with eight upwardly inclined water flow holes 104 with a size of 5 mm × 6 mm in a circumferential direction near the bottom of the inlet temperature measuring component 9. The coolant drained from the lower part of the drainage component 10 flows out through the eight water flow holes after passing through the end of the inlet temperature measuring structure.

[0057] In this embodiment, the outer diameter of the drainage component terminal section 105 is Φ20 mm and the inner diameter is Φ8 mm. The inner diameter is expanded to Φ12 mm at the very end of the drainage component terminal section, and four 10 mm×5 mm drainage holes 106 are circumferentially opened.

[0058] A bowl-shaped intercepting structure 107 and an end plug 108 are welded to the end of the end section of the drainage component; the coolant flowing from top to bottom is collected by the intercepting structure 107 and enters the drainage structure through the drainage hole 106, and is turned 90 degrees under the drainage guide of the end plug 108 to flow vertically upward.

[0059] The upper part of the end plug 108 is conical, which is conducive to changing the direction of fluid flow; the lower part of the end plug 10.8 is a tapered bullet-shaped one, which can prevent the water flow from forming turbulent flow. Figure 5 .

[0060] The pressure vessel top cover of the present invention is provided with three reactor outlet temperature measuring assemblies and three reactor inlet measuring assemblies, and all temperature measuring assemblies are vertically inserted into the pressure vessel. The reactor outlet temperature measuring assembly 4 is a pressure-bearing structure with a variable cross-section design, which realizes the disassembly and assembly of the thermocouple thermometer without drainage and shortens the response time. The reactor inlet temperature measuring assembly 5 is composed of an inlet temperature measuring component 9 and a drainage component 10, and the inlet temperature measuring component 9 has the same structure as the reactor outlet temperature measuring assembly 4. The drainage component 10 adopts a cut-off structure and a drainage hole at the end to introduce the coolant flowing from top to bottom into the drainage structure, and then return and flow vertically upward to the temperature measuring structure, and then flow out through the water hole on the drainage structure next to the temperature measuring structure, thereby realizing the reactor inlet measurement above the active section of the core.

[0061] The present invention uses a diversion component 10 to divert the reactor inlet coolant from the bottom of the pressure vessel to the top of the core active section, thereby avoiding the use of thermocouples to measure the temperature in the highly irradiated core active section; the end of the diversion component uses a bowl-type cut-off structure 107, a diversion hole and an end plug 108 to divert the coolant into the diversion structure and return it to flow upward.

[0062] The embodiments of the present invention are described in detail above. The present invention is not limited to the above embodiments. Various changes can be made within the knowledge of ordinary technicians in this field without departing from the scope of the present invention.

Claims

1. A reactor coolant temperature measuring device, characterized in that: include: Three reactor outlet temperature measurement assemblies (4) and three reactor inlet temperature measurement assemblies (5), the reactor outlet temperature measurement assemblies (4) and the reactor inlet temperature measurement assemblies (5) are respectively installed on the pressure vessel top cover; the three reactor outlet temperature measurement assemblies (4) are installed on the pressure vessel top cover at intervals of 120 degrees and vertically inserted into the pressure vessel, and the three reactor inlet temperature measurement assemblies (5) are also distributed on the pressure vessel top cover at intervals of 120 degrees and vertically inserted into the pressure vessel, and there is an angle of 15 degrees between adjacent reactor outlet temperature measurement assemblies and reactor inlet temperature measurement assemblies; The reactor inlet temperature measurement assembly (5) comprises: an inlet temperature measurement component (9) and a drainage component (10); the inlet temperature measurement component (9) is arranged inside the drainage component (10); the drainage component (10) comprises: a drainage component installation section (101), a drainage component root section (102), a drainage component reduced diameter section (103), eight water flow holes (104), a drainage component end section (105), four drainage holes (106), a shut-off component (107), and an end plug (108); The drainage component (10) is a hollow structure as a whole. The top of the drainage component (10) is a drainage component mounting section (101), and below the drainage component mounting section (101) is a drainage component root section (102); below the drainage component root section (102) is a drainage component reduced diameter section (103); below the drainage component reduced diameter section (103) is a drainage component terminal section (105), and four drainage holes (106) are arranged in an annular manner on the drainage component terminal section (105); a shut-off component (107) is welded to the bottom of the drainage component terminal section (105); and an end plug (108) is provided on the shut-off component (107); Eight water flow holes (104) are arranged in a ring on the reduced diameter section (103) of the drainage component, and the opening direction of the water flow holes (104) is inclined upward.

2. A reactor coolant temperature measuring device according to claim 1, characterized in that: The reactor outlet temperature measurement assembly (4) comprises: a reactor outlet temperature measurement tube (411) and a thermocouple thermometer (7); the reactor outlet temperature measurement tube (411) is provided with a thermocouple thermometer (7); The reactor outlet temperature measuring tube (411) comprises: a reactor outlet temperature measuring tube installation section (41), a reactor outlet temperature measuring tube root section (42), a reactor outlet temperature measuring tube reduced diameter section (43), and a reactor outlet temperature measuring tube terminal section (44); The top of the reactor outlet temperature measuring tube root section (42) is the reactor outlet temperature measuring tube installation section (41); the bottom of the reactor outlet temperature measuring tube root section (42) is the reactor outlet temperature measuring tube reduced diameter section (43); the bottom of the reactor outlet temperature measuring tube reduced diameter section (43) is the reactor outlet temperature measuring tube terminal section (44); the reactor outlet temperature measuring tube root section (42), the reactor outlet temperature measuring tube reduced diameter section (43), and the reactor outlet temperature measuring tube terminal section (44) are all hollow tubular structures, the inner diameter of the reactor outlet temperature measuring tube root section (42) is larger than the inner diameter of the reactor outlet temperature measuring tube reduced diameter section (43), and the inner diameter of the reactor outlet temperature measuring tube reduced diameter section (43) is larger than the inner diameter of the reactor outlet temperature measuring tube terminal section (44).

3. The reactor coolant temperature measuring device according to claim 2, characterized in that: The thermocouple thermometer (7) comprises: a thermocouple thermometer mounting section (71), a support tube (72), a thermocouple (73) and a thermocouple reduction section (74); the top of the support tube (72) is provided with the thermocouple thermometer mounting section (71); the bottom of the support tube (72) is the thermocouple (73), and the bottom of the thermocouple (73) is provided with the thermocouple reduction section (74).

4. A reactor coolant temperature measuring device according to claim 3, characterized in that: The bottom of the inlet temperature measuring component (9) is located at the reduced diameter section (103) of the guide component (10), that is, the coolant guided from the lower part of the guide component (10) flows out through the eight water holes after passing through the end of the inlet temperature measuring component (9).

5. The reactor coolant temperature measuring device according to claim 4, characterized in that: The shut-off component (107) is a bowl-shaped structure as a whole, and an end plug (108) is provided at the central portion of the shut-off component (107); The coolant is collected by the intercepting component (107), then passes through the drainage guide of the end plug (108), turns 90 degrees, and flows vertically upward into the interior of the drainage component (10) through the drainage hole (106).

6. The reactor coolant temperature measuring device according to claim 5, characterized in that: The upper portion of the end plug (108) is a conical structure, which is conducive to changing the flow direction of the fluid; the lower portion of the end plug (108) is a bullet-shaped structure with a tapered diameter, which prevents the water flow from forming turbulent flow.

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