GB2534491A

GB2534491A - Heat pipe

Info

Publication number: GB2534491A
Application number: GB1603824.2A
Authority: GB
Inventors: He Xiangyan; Chen Jun; Song Lei; Li Dongsheng; Zhou Zhou; Jiang Xiaohua
Original assignee: China General Nuclear Power Corp; China Nuclear Power Technology Research Institute Co Ltd; CGN Power Co Ltd
Current assignee: China General Nuclear Power Corp; China Nuclear Power Technology Research Institute Co Ltd; CGN Power Co Ltd
Priority date: 2014-11-11
Filing date: 2015-04-16
Publication date: 2016-07-27
Anticipated expiration: 2035-04-16
Also published as: WO2016074436A1; CN104376882A; GB201603824D0; CN104376882B; GB2534491B

Abstract

A heat pipe (200), connected to a nuclear reactor pressure vessel (100); several temperature measuring points are provided on a wall surface of the heat pipe (200); a horizontal plane where the axis of the heat pipe (200) is located is a reference plane (200A), along the flowing direction of the fluid in the heat pipe (200), a portion of the reference plane (200A) on the right side of the axis of the heat pipe (200) forms an included angle with a plane penetrating the axis of the heat pipe (200) in a counterclockwise direction, and the number of the temperature measuring points within an acute angle region (210) between a 25° included angle plane and a 35°included angle plane is equal to the number of the temperature measuring points within an acute angle region (240) between a 290°included angle plane and a 310°included angle plane. The heat pipe arranges the temperature measuring points according to a water temperature stratification, thus enabling a measured temperature to be approximate to an actual temperature, and increasing risk control of a nuclear power plant.

Description

II( T-ATER PIPE

RELATED APPLICATIONS

[0001] This application claims the benefit of priorit to Chinese Patent Application No. 201410631637.0, filed on November 11, 2014, which is hereby incorporated by reference in its entirety.

FIELD OF THE INVENTION

100021 The present invention relates to a nuclear device and, more particularly to a hot-water pipe for connecting with a. reactor pressure vessel to drain water therein.

BACKGROUND OF THE INVENTION

[0003] Currently,the operational status of nuclear reactors can be learned by detecting water temperature conditions of hot water drained from a hot-water pipe and analyzing the water temperature conditions. in conventional nuclear power units, three or four temperature measuring points are evenly arranged at the sidewall of the hot-water pipe, the average temperature measured at the temperature measuring points is close to the actual temperature of the hot-water pipe.

[0004] The above conventional temperature measuring method of the hot-water pipe is too simple" and the average temperature can not accurately reflect the water temperature inside the hot-water pipe, so it is not conducive to controlling the nuclear power unit.

100051 Therefore, a new water temperature measuring in (hod of the hot-water pipe is needed to improve the temperature measurement accuracy of the hot-water pipe and enhance the operational risk control of nuclear power unit.

SUMMARY OF THE INVENTION

[0006] One objective of the present invention s to provide a hot-water pipe for easily measuring the water temperature therein and increasing the temperature measurement accuracy.

100071 To achieve the above-mentioned objectives, a hot-water pipe is adapted to be connected to a reactor pressure vessel, a sidewall of the hot-water pipe is configured with a plurality of temperature measuring points, a horizontal plane. where the axis of the hot-water pipe is located is called a reference plane; along a direction of fluid flow within the hot-water pipe, a portion of the reference plane located at a right side of the axis of the hot-water pipe is angled with a plane passing through the axis of the hot-water pipe in the counterclockwise direction in a certain degree and the plane being called a certain degree angle plane, some of the temperature measuring points are arranged in an acute angle region between a 25 degree angle plane and a 35 degree angle plane, and above the reference plane, some of the temperature measuring points are arranged in an acute angle region between a 290 degree angle plane and a 310 degree angle plane and below the reference plane, and the number of the temperature measuring points in the acute angle region between the 25 degree angle plane and the 35 degree angle plane is equal to that of the temperature measuring points in the acute angle region between the 290 degree angle plane and the 310 degree angle plane, [0008] Water temperature stratification is found by temperature monitoring and calculation within the hot-water pipe, however, the water temperature stratification is not commonly understood that the.gh-temperature water is at the upper side and the low-temperature water is at the lower side. According to the results of the temperature monitoring and calculation within the hot-water pipe, the cold zone of the hot-water pipe is close to the bottom of the hot-water pipe and sometimes appears in the center of the hot-water pipe; the hot zone generally appears in the obliquely upper part of the hot-water pipe, rather than at the upper side of the hot-water pipe; the temperature of a boundary zone of the cold zone and the hot zone is closer to the, average temperature of a cross-sectional of the hot-water pipe, namely, the boundary zone is a temperature transition zone. Therefore, the position arrangement of the temperature measuring points is crucial to the temperature measurement accuracy. In this regard, the present invention provides a hot-water pipe, and arranges two temperature measuring points respectively at one side of the temperature transition zone that is close to the hot zone and at the other side of the temperature transition zone that is close to the cold zone according to the water temperature stratification in the hot-water pipe, the average temperature of the two temperature measuring points can reflect the average temperature of the hot-water pipe, and also able to reflect temperature fluctuations within the hot-water pipe, thereby enhancing the risk control of nuclear power unit.

[00091 Preferably, at least one of the temperature measuring points is arranged between a 115 degree angle plane and a 125 degree angle plane, and the at least one of the temperature measuring points between the 115 degree angle plane and the 125 degree angle plane is located above the reference plane. Arranging a temperature measuring point in the hot zone to obtain a temperature datum to reflect the high-temperature fluctuations within the hot-water pipe.

100101 Preferably, at least one of the temperature measuring points also is arranged between a 190 degree angle plane and a 230 degree angle plane, and the at least one of the temperature measuring points between the 190 degree angle plane and the 230 degree angle plane is located below the reference plane. Arranging a temperature measuring point in the cold zone to obtain a temperature datum to reflect the low-temperature fluctuations within the hot-water pipe.

[00111 Preferably, the umber of the temperature measuring points is four.

[00121 Preferably, a distance from any one of the temperature measuring points to an outlet of the reactor pressure vessel is greater than three meters. Fluid enters into the hot-water pipe after being drained from reactor pressure vessel, the temperature difference is gradually reduced as the flow distance increases, and the temperature is gradually stabilized at a position that is greater than three meters distant from the outlet of the reactor pressure vessel. So the temperature measuring points are configured at the positions that is greater than three meters distant from the outlet of the reactor pressure vessel, the water temperature within the hot-water pipe has been gradually stabilized, so the measuring temperature is stable, which can better reflect the operational status of the nuclear power unit.

[00131 Preferably, a plurality of temperature measuring holes are defined in the sidewall of the hot-water pipe, and any one of the temperature measuring holes constitutes one temperature measuring point.

100141 Preferably, each temperature measuring hole is connected with a temperature measuring nozzle. The temperature measuring nozzle directly measures the current temperature of this temperature measuring point, and the measured temperature is more accurate.

100151 Preferably, each temperature measuring hole is connected with a diversion pipe. Water from temperature measuring point is guided to a temperature measuring bypass by the diversion pipe so as to he mixed and measured, thereby improving:, the safety of the nuclear power unit.

BRIEF DESCRIPTION OF FETE DRAWINGS

[00161 The accompanying drawings facilitate an understanding of the various embodiments of this invention. In such drawings: [00171 Fig. I is a sectional view of a hot-water pipe connecting with a reactor pressure vessel; and [00181 Fig.2 is a distribution diagram of temperature measuring points along a direction of fluid flow ithin the hot-water pipe.

DETAILED DESCRIPTION OF ILLUSTRATED EMBODIMENTS

100191 Various preferred ei bodiments of the invention will now be described with reference to the figures, wherein like reference numerals designate similar parts throughout the various [0020] Referring to Fig. 1, the nuclear power unit includes a reactor pressure vessel 100, a hot-water pipe 200 communicating with the reactor pressure vessel 100 to drain high-temperature a er that have absorbed nuclear heat to work. The temperature of the water at an outlet of the reactor pressure vessel 100 or in the hot-water pipe 200 is unevenly distributed because of the uneven distribution of reactor core heat release. The temperature difference is gradually reduced as the distance of the water flow within the hot-water pipe 200 increases and the water in the hot-water pipe 200 is mixed, and the temperature is gradually stabilized at a position that is greater than three meters distant from the outlet of the reactor pressure vessel 100. So the temperature measuring points are arranged at the positions that is greater than three meters distant from the outlet of the reactor pressure vessel 100, at these positions the water in the hot-water pipe 200 has been mixed completely, the temperature distribution is more stable, which can better reflect the operational status of the nuclear power unit.

[0021] Currently, temperature stratification in the hot-water pipe 200 is formed due to different water temperature, in a cross-section of the hot-water pipe 200, the high -temperature water is at the upper side of the hot-water pipe 200, the foxy-temperature water is at the lower side of the hot-water pipe 200, and a temperature transition zone is formed in the center of the hot-water pipe 200 and between the high-temperature water and the low-temperature water.

[0022] Water temperature stratification is found by temperature monitoring and calculation within the hot-water pipe 200, however, the water temperature stratification is not commonly understood that the high-temperature water is at the tipper side and the low-temperature water is at the lower side. According to the results of the temperature monitoring and calculation within the hot-water pipe 200, the cold zone of the hot-water pipe 200 is close to the bottom of the hot-water pipe 200 and sometimes appears in the center of the hot-water pipe 200; the hot zone generally appears in the obliquely upper part of the hot-water pipe 200, rather than at the upper side of the hot-water pipe 200; the temperature of boundary zone of the cold zone and the hot zone is closer to the average temperature of a cross-sectional of the hot-water pipe 200, namely, the boundary zone is a. temperature transition zone. Therefore, the position arrangement of the temperature measuring points is crucial to the temperature measurement accuracy.

[0023] In this regard, the present invention provides a hot-water pipe 200, and arranges two temperature measuring points respectively at one side of the temperature transition zone that is close to the hot zone and at the other side of the temperature transition zone that is close to the cold. zone according to the water temperature stratification of-water pipe 200; the average temperature of the two temperature measuring points can reflect the average temperature of the hot-water pipe 200, and also able to reflect temperature fluctuations within the hot-water pipe 200, thereby enhancing he risk control of nuclear power unit. in conjunction with Fig. 2, the arrangement of the temperature measuring points of the hot-water pipe 200 will he described as follows.

100241 A horizontal plane where the axis of the hot-water pipe is located is defined as a reference plane 200A; along a direction of fluid flow within the hot-water pipe 200, a portion of the reference plane 200A located at a right side of the axis of the hot-water pipe 200 is angled with a plane passing through the axis of the hot-water pipe 200 in the counterclockwise direction in a certain degree and the plane is called a certain degree angle plane. For the convenience of explanation, multiple planes passing through the axis of the hot-water pipe 200 are distinguished by different degrees between the planes themselves and the portion of the reference plane 200A located at the right side of the axis of the hot-water pipe 200 in the counterclockwise direction, such as, if the degree between a plane passing through the axis of the hot-water pipe 200 and the portion of the reference plane 200A located at the right side of the axis of the hot-water pipe 200 in the counterclockwise direction is 25 degree, then the plane passing through the axis of the hot-water pipe 200 is a 25 degree angle plane. Two opposite acute angle regions are formed between the 25 degree angle plane and a 35 degree angle plane, and the sidewall of the hot-water pipe 200 in one acute angle region located above the reference plane 2001 constitutes a fist zone 210. Two opposite acute angle regions are formed between a 115 degree angle plane and a 125 degree angle plane, and the sidewall of the hot-water pipe 200 in one acute angle region located above the reference plane 200A constitutes a second zone 220. Two opposite acute angle regions are formed between a 190 degree angle plane and a 230 degree angle plane, and the sidewall of the hot-water pipe 200 in one acute angle region located below the reference plane 200A constitutes a third zone 230. Two opposite acute angle regions are lonn.ed between a. 290 degree angle plane and a 310 degree angle plane, and the sidewall of the hot-water pipe 200 in one acute angle region located below the reference plane 2004 constitutes a fourth zone 240. The temperature measuring points are arranged at the sidewall of the hot-water pipe 200, and respectively arranged in the first zone 210, the second zone 220, the third zone 230, and the fourth zone 240. The hot-water pipe 200 of the present invention has multiple the temperature measuring points, the number of the temperature measuring points in the first zone 210 is the same as in the fourth zone 240, while the temperature measuring points in the second and third zones 220, 230 are not limited.

100251 Preferably, the umber of the temperature measuring points is four. Following the above descriptions for the positions of the temperature 'measuring points of the hot-water pipe 200, there are four methods to arrange the temperature measuring points at the hot-water pipe 200: firstly, the first zone 210 and the fourth zone. 240 are respectively arranged with two temperature measuring points, and the second zone 220 and the third zone 230 have no temperature measuring point; secondly, the first zone 210, the second zone 220, the third zone 230,, and the fourth zone 240 are respectively arranged with one temperature measuring point; thirdly, the first zone 210 and the fourth. zone 240 are respectively arranged with one temperature measuring point, the second zone 220 is arranged with two temperature measuring points, and the third zone 230 has no temperature measuring point; fourthly,the first zone 210 and the fourth zone 240 are respectively arranged with one temperature measuring point, the second zone 220 has no temperature measuring point, and the third zone 230 is arranged with two temperature measuring points.

[00261 The tint zone 2 tO, the second zone 220, the third zone 230 and the fourth zone 240 of the hot-water pipe 200 cover the cool zone, the hot zone and the temperature transition zone. The above arrangement of the temperature measuring points covers each zone, even the water temperature stratification is changed in the hot-water pipe 200 at times, and this arrangement can still reflect the average temperature and temperature fluctuations within the hot-water pipe 200.

[00271 Further, the temperature measuring points 200 can be arranged in a same cross-section of the hot-water pipe 200, or can be arranged in different cross-sections of the hot-water pipe 200, which would not obviously affect the measuring results of the temperature of the hot-water pipe 200.

10028 Preferably, multiple temperature measuring h are opened in the sidewall of the hot-water pipe 200 to form the temperature measuring points for measuring the water temperature in the hot-water pipe 200. In one embodiment, a temperature measuring nozzle is soldered to the temperature measuring hole, and the temperature of the temperature measuring point can be directly measured by a temperature detector configured in the temperature measuring nozzle. In another embodiment, a diversion pipe is connected to the temperature measuring hole, a certain amount of water drawn from each temperature measuring hole is guided to a temperature measuring bypass by the diversion pipe to be mixed, and then the water temperature can be measured. The operational status of the nuclear power unit can be easily and accurately learned by analyzing the temperature datathereby enhancing the risk control of nuclear power unit.

[0029] the present invention provides a hot-water pipe 200, and arranges two temperature measuring points respectively at one side of the temperature transition zone that is close to the hot zone and at the other side of die temperature transition zone that is close to the cold zone according to the water temperature stratification in the hot-water pipe 200, the average temperature of the two temperature measuring points can reflect the average temperature of the hot-water pipe 200, additionally, the present invention further arranges a temperature measuring point in the hot zone and a temperature measuring point in the cold zone, the temperature data thereof can reflect the temperature fluctuations within the hot-water pipe 200. The temperature measuring point cover the cool zone, the hot zone and the temperature transition zone of the hot-water pipe 200, even the water temperature stratification is changed in the hot-water pipe 200 at times, and this arrangement can still reflect the average temperature and temperature fluctuations within the hot-water pipe 200, thereby enhancing the risk control of nu clear power unit.

[0030] While the invention has been described in connection with what are presently considered to he the most practical and preferred embodiments, it is to be imderstood that the invention is not to be limited to the disclosed embodiments, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the invention.

Claims

WHAT IS CLAIMED IS: 1. A hot-water pipe, adapted to be connected to a reactor pressure vessel, a side fall of the hot-water pipe being configured with a plurality of temperature measuring points, a horizontal plane where the axis of the hot-water pipe is located being called a reference plane; along a direction of fluid flow within the hot-water pipe, a portion of the reference place located at a right side of the axis of the hot-water pipe being angled with a plane passing through the axis of the hot-water pipe in the counterclockwise direction in a certain degree and the plane being called a certain degree angle plane, some of the temperature measuring points being arranged in an acute angle region between a 25 degree angle plane and a 35 degree angle plane and above the reference plane; some of the temperature measuring points being arranged in an acute angle region between a 290 degree angle plane and a 310 degree angle plane and below the reference plane, and the number of the temperature measuring points in the acute angle region between the 25 degree angle plane and the 35 degree angle plane being equal to of the temperature measuring points in the acute angle region between the 290 degree angle plane and the 310 degree angle plane.
2. The hot-water pipe according to claim f, wherein at least one of the temperature measuring points is arranged between a -115 degree angle plane and a 125 degree angle plane, and the at least one of the temperature measuring -points between the 115 degree angle plane and the 125 degree angle plane is located above the reference plane.
The hot-water pipe according o claim I, wherein at least one of the temperature measuring points is arranged between a 190 degree angle plane and t a 230 degree angle plane, and the at least one of the temperature measuring points between the 190 degree angle plane and the 230 degree angle plane is located below the reference plane.
4. The hot-water pipe according to claim 1, wherein the umber of the temperature measuring points is four
5. The hot-water pipe according to claim 1, wherein a distance from any one of the temperature measuring points to an outlet of the reactor pressure vessel is greater than three meters.
6. The hot-water pipe according to claim 1,wherein a plurality of temperature measuring holes are defined in the sidewall of the hot-water pipe, and any one of the temperature measuring holes constitutes one temperature measuring point.
7. The hot-water pipe according to claim 6, wherein each temperature measuring hole is connected with a temperature measuring nozzle.
8. The hot-water pipe according to claim 6, wherein each t npera measuring hole is connected with a diversion pipe.