CN211207164U

CN211207164U - Power supply connection structure for tracing heat of boron-containing pipeline and equipment of nuclear power station

Info

Publication number: CN211207164U
Application number: CN201921963834.7U
Authority: CN
Inventors: 范遂; 杨萧; 谭悦; 闫桂银; 刘福瑞
Original assignee: China Nuclear Power Engineering Co Ltd
Current assignee: China Nuclear Power Engineering Co Ltd
Priority date: 2019-11-13
Filing date: 2019-11-13
Publication date: 2020-08-07
Anticipated expiration: 2029-11-13

Abstract

The utility model relates to a power supply connection structure that is used for boron-containing pipeline of nuclear power station and equipment to accompany heat, for the electric heat tracing heating circuit power supply that uses mineral insulated cable, electric heat tracing heating circuit includes heat tracing cable and the thermal resistance that corresponds with it, and the temperature signal of thermal resistance connects to on-the-spot electric cabinet, and the distribution board is connected to the electric cabinet, provides the power by the distribution board, heat tracing cable is supplied power by one kind or two kinds of voltage levels. The utility model discloses an electric tracing heating circuit has more nimble mounting means, and its power supply connection structure only uses two kinds at most voltage levels, has avoided using high-power transformer, has reduced the equipment size, and the cost has been saved in the installation of the companion's of being convenient for equipment that accompanies heat.

Description

Power supply connection structure for tracing heat of boron-containing pipeline and equipment of nuclear power station

Technical Field

The utility model belongs to the nuclear power station design technique, concretely relates to a supply connection structure that is used for boron-containing pipeline of nuclear power station and equipment to accompany heat.

Background

A large number of boron-containing process pipelines exist in the nuclear power station, and a boron heat tracing system is required to be arranged for tracing a pipeline system in order to maintain normal circulation of a boron solution and prevent crystallization of boric acid, so that process media in the pipeline system can be used during normal operation or shutdown of the nuclear power station. As the boron-containing pipeline has radioactivity and the service life of the heat tracing cable is required to be consistent with that of the pipeline, generally 40 years or 60 years, the boron heat tracing system generally uses the mineral insulated cable with radiation resistance and long service life, and cannot use the heat tracing cable with self-temperature control or the constant-power heat tracing cable which is frequently used in the conventional industry. In the conventional boron heat tracing system of the nuclear power station, a high-power transformer is arranged in heat tracing equipment for generating 7 voltage levels (12, 24, 48, 72, 96, 144 and 220VAC) for supplying power, and as shown in figure 1, the heat tracing equipment has the advantages of large volume, high cost and large design workload.

SUMMERY OF THE UTILITY MODEL

The utility model aims at the problem that exists among the prior art, provide a supply connection structure that is used for boron-containing pipeline of nuclear power station and equipment to accompany heat, do not use powerful transformer in heat tracing equipment to reduce heat tracing equipment volume, save the cost and simplify design work simultaneously.

The technical scheme of the utility model as follows: a power supply connection structure for tracing of boron-containing pipelines and equipment in nuclear power stations supplies power for an electric tracing heating loop using mineral insulated cables, wherein the electric tracing heating loop comprises a tracing cable and a thermal resistor corresponding to the tracing cable, a temperature signal of the thermal resistor is connected to an on-site electric cabinet, the electric cabinet is connected with a distribution board, a power supply is provided by the distribution board, and the tracing cable is supplied with power by one or two voltage levels.

Further, the power supply connection structure for the boron-containing pipeline and equipment heat tracing of the nuclear power station is characterized in that the heat tracing cable is supplied with the class A voltage alone or with the class A voltage and the class B voltage with a low voltage level, and the class A voltage and the class B voltage are both supplied by the switchboard.

Further, as described above, the power supply connection structure for the boron-containing pipeline and equipment heat tracing of the nuclear power plant, wherein the heat tracing cable is supplied with power by using class a voltage alone, or by using class a voltage provided by the switchboard and class B voltage of a low voltage level, and the class a voltage is provided by a low-power switching power supply or linear power supply after being converted by the class a voltage.

Further, the power supply connection structure for the boron-containing pipeline and equipment heat tracing of the nuclear power station is as described above, wherein the class A voltage is 220VAC, and the class B voltage is 24 VAC.

The utility model has the advantages as follows: the utility model discloses an electric tracing heating circuit has more nimble mounting means, and its power supply connection structure only uses two kinds at most voltage levels, has avoided using high-power transformer, has reduced the equipment size, and the cost has been saved in the installation of the companion's of being convenient for equipment that accompanies heat.

Drawings

FIG. 1 is a schematic structural diagram of a boron heat tracing system of a nuclear power station in which a high-power transformer is arranged in heat tracing equipment;

FIG. 2 is a schematic diagram of an embodiment of an electrical tracing control system for boron-containing pipelines of a nuclear power plant;

in FIG. 2, - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -,

as power cables

FIG. 3 is a schematic diagram of a power supply configuration in which class A voltages are provided by a power distribution board and class B voltages are provided by a low power switching power supply or a linear power supply after class A voltage conversion in an exemplary embodiment;

FIG. 4 is a schematic diagram of a power supply configuration in which both class A and class B voltages are provided by a power distribution board in an exemplary embodiment.

Detailed Description

The present invention will be described in detail with reference to the accompanying drawings and examples.

As shown in fig. 2, for a boron-containing process pipeline system of a nuclear power station, a normal heat tracing cable and a standby heat tracing cable are arranged in each heat tracing loop and respectively correspond to a normal heat resistor and a standby heat resistor, temperature signals of the heat resistors are respectively connected to field electric cabinets of the normal loop and the standby loop, and equipment such as a control module, a circuit breaker, a contactor, a communication module and the like is installed in each field electric cabinet. Each electric cabinet is powered by a corresponding normal or standby loop switchboard, a controller arranged in the electric cabinet receives a temperature signal of the thermal resistor, and outputs a control signal to the contactor after logic judgment so as to control the start and stop of the heat tracing cable and heat tracing the process pipeline. And a display lamp is arranged on the surface of the electric cabinet to indicate information such as tripping of the circuit breaker. The electric cabinet transmits the analog quantity signal of 4-20mA and the switching value signal to the switch cabinet in a communication mode, a touch screen arranged on the electric cabinet can display temperature signals and alarm signals, meanwhile, data can be uploaded to the switch cabinet through the photoelectric conversion module, and the switch cabinet collects the data of the electric cabinets and then uploads the data to the whole plant DCS for display.

The utility model discloses a heat tracing cable is supplied power by one kind or two kinds of voltage levels, that is to say, heat tracing cable can the exclusive use A level voltage power supply, perhaps uses A level voltage and low-voltage level's B level voltage power supply.

In the embodiment, the power supply of each heat tracing cable comprises power supply by using class A voltage (220VAC) alone or power supply by using class A voltage (220VAC) and class B voltage (24VAC), wherein the 220VAC is provided by an upstream power distribution board, and the 24VAC is provided by the upstream power distribution board or provided by low-power switch power supply or linear power supply after being converted by the 220 VAC.

In the control device shown in fig. 3, the class a voltage is provided by an upstream power distribution cabinet, and the class B voltage is supplied by a low-power switching power supply or a linear power supply after the class a voltage is converted.

The supply voltage of not more than two voltage classes is provided directly by the upstream switch board in the control device shown in fig. 4. Both ways can avoid the use of high power transformers in the control device. The two modes shown in fig. 4 are relative to the one mode shown in fig. 3, in which a transformer is added in an upstream power distribution cabinet, a power cable between the power distribution cabinet and the control equipment is added, but a switching power supply or a linear power supply is avoided in the control equipment. The first mode and the second mode can be selected according to specific engineering design requirements.

The system firstly selects 220VAC power supply, and if the 220VAC can not be selected to the heat tracing cable, 24VAC power supply is selected. For each supply loop, the vast majority of supply loops use 220VAC for supply, according to the formula: power (voltage)²Resistance, the 220VAC power supply is verified, if the required power is too small, when the 220VAC power supply is used, the resistance requirement of the heat tracing cable is high, the section requirement of the heat tracing cable is thin and exceeds the specification of the optional heat tracing cable, and at the moment, 24VAC power supply is used. According to the power supply mode, the voltage design and the power supply loop design are combined, the specification of the heat tracing cable is not increased on the premise of realizing the function of the original heat tracing system, the voltage grade is greatly reduced, a high-power transformer is avoided, the size of equipment is reduced, the heat tracing equipment is convenient to install, the cost is saved, and the loop design work of voltage grade distribution is reduced.

It will be apparent to those skilled in the art that various changes and modifications can be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims and their equivalents, the present invention is also intended to include such modifications and variations.

Claims

1. The utility model provides a power supply connection structure that is used for boron-containing pipeline of nuclear power station and equipment to accompany heat, for the electric tracing heating circuit power supply that uses mineral insulated cable, its characterized in that: the electric heat tracing heating loop comprises a heat tracing cable and a thermal resistor corresponding to the heat tracing cable, a temperature signal of the thermal resistor is connected to an on-site electric cabinet, the electric cabinet is connected with a distribution board, a power supply is provided by the distribution board, and the heat tracing cable is powered by one or two voltage grades.

2. The electrical supply connection structure for the boron-containing pipe and equipment heat tracing of a nuclear power plant as claimed in claim 1, wherein: the heat tracing cable is supplied with A-class voltage alone or with B-class voltage of low voltage level, and both the A-class voltage and the B-class voltage are provided by the switchboard.

3. The electrical supply connection structure for the boron-containing pipe and equipment heat tracing of a nuclear power plant as claimed in claim 1, wherein: the heat tracing cable is supplied with power by using class A voltage alone or by using class A voltage and class B voltage with low voltage level, the class A voltage is provided by the switchboard, and the class B voltage is provided by a low-power switch power supply or a linear power supply after being converted by the class A voltage.

4. The power supply connection structure for the boron-containing pipe and equipment heat tracing of the nuclear power plant as claimed in claim 2 or 3, wherein: the class A voltage is 220VAC, and the class B voltage is 24 VAC.