EP3598845A1 - Système de chauffage de trace pour une machine d'écoulement de fluide - Google Patents

Système de chauffage de trace pour une machine d'écoulement de fluide Download PDF

Info

Publication number
EP3598845A1
EP3598845A1 EP18186484.4A EP18186484A EP3598845A1 EP 3598845 A1 EP3598845 A1 EP 3598845A1 EP 18186484 A EP18186484 A EP 18186484A EP 3598845 A1 EP3598845 A1 EP 3598845A1
Authority
EP
European Patent Office
Prior art keywords
cable
outer casing
mineral
heating system
joint
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP18186484.4A
Other languages
German (de)
English (en)
Inventor
Alexander GOSTOMELSKY
Yevgen Kostenko
Karl Funken
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Siemens AG
Original Assignee
Siemens AG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Siemens AG filed Critical Siemens AG
Publication of EP3598845A1 publication Critical patent/EP3598845A1/fr
Withdrawn legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B3/00—Ohmic-resistance heating
    • H05B3/02—Details
    • H05B3/06—Heater elements structurally combined with coupling elements or holders
    • H05B3/08—Heater elements structurally combined with coupling elements or holders having electric connections specially adapted for high temperatures
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B3/00—Ohmic-resistance heating
    • H05B3/40—Heating elements having the shape of rods or tubes
    • H05B3/54—Heating elements having the shape of rods or tubes flexible
    • H05B3/56—Heating cables
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B2203/00—Aspects relating to Ohmic resistive heating covered by group H05B3/00
    • H05B2203/021—Heaters specially adapted for heating liquids
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B2203/00—Aspects relating to Ohmic resistive heating covered by group H05B3/00
    • H05B2203/022—Heaters specially adapted for heating gaseous material

Definitions

  • the invention relates to a trace heating system for a fluid flow machine.
  • the invention further relates to a fluid flow machine with a trace heating system as well as to a method for connecting cables inside an outer casing of a fluid flow machine.
  • One of the methods to improve efficiency of gas or steam power plants is to achieve better thermal match between the rotating and the stationary components using a trace heating system.
  • a trace heating system When such electrical trace heating system is installed e.g. on the compressor vane carrier (CVC) to actively control the temperature of the compressor vane carrier, several technical challenges must be overcome. Some of these difficulties are related to realizing of the electrical wiring, in particular the transition between mineral insulated (MI) cables and cables without such insulation.
  • a first mineral insulated cable is mounted at the inner casing and heats it up.
  • the temperature increase is based on the physical principal of electrical current through electrical resistance, i.e. the mineral insulated cable.
  • Mineral insulation coating is used in the first place to insulate the electrical conductor (wire) and besides to transfer the heat energy coming from the electrical conductor to the inner casing to increase its temperature.
  • the electrical trace heating system also comprises a second mineral insulated cable with an identical structure to the first mineral insulated cable, but with a larger core diameter, and consequently of less electrical resistance.
  • the second mineral insulated cable After the second mineral insulated cable is led out from outer casing, there is a transition to conventional electrical wires without mineral insulation which do not require operating under high temperatures as it is the case inside a compressor, a gas turbine or a steam turbine.
  • This transition between the second mineral insulated cable and the conventional cable is realized by a hermetic sealing which insulates the mineral insulated cable core from outside. Since the first mineral insulated cable is very good attached to inner casing, the transition between the inner and the outer casing is the weakest link and is more likely to be damaged, e.g. due to relative motion between the casings, vibrations, etc.
  • the object of the present invention is, therefore, to enable the use of a more flexible cable without mineral insulation, which is connected to a mineral insulated cable inside a fluid flow machine and is then led out of the outer casing.
  • a trace heating system for a fluid flow machine having an outer casing and an inner casing, comprising: at least one mineral insulated cable extending inside the outer casing, at least one cable without mineral insulation, the cable extending at least partially outside the outer casing, and a joint between the mineral insulated cable and the cable without mineral insulation, wherein the second joint is designed as high temperature resistant electrical joint by sealing a welding joint using insulating ceramic material.
  • a fluid flow machine comprising an outer casing and an inner casing, further comprising such trace heating system.
  • a fluid flow machine within the meaning of the present invention has an outer casing, an inner casing (when the fluid flow machine is a compressor, the inner casing is the compressor vane carrier) and a gap between the outer casing and the inner casing.
  • the function of the trace heating system is to actively control the temperature of the inner casing and of the rotor.
  • at least one mineral insulated cable is mounted on the inner casing.
  • the mineral insulated cable extends only inside the outer casing.
  • This mineral insulated cable is connected to a cable without mineral insulation, wherein the cable without mineral insulation extends partly inside the outer casing and partly outside the outer casing.
  • the essential idea of the present invention is that it is only possible to use a cable without mineral insulation inside the outer casing of a fluid flow machine and to lead it out of the outer casing, when a high temperature resistant electrical joint is provided that is eligible for connecting the cable without mineral coating with the mineral insulated cable.
  • the high temperature resistant electrical joint allows a sealed connection between the mineral insulated cable and the cable without mineral insulation, so that the cable without mineral insulation is protected both against high temperatures and moisture.
  • the high temperature resistant electrical joint composition is based on a ceramic formula and is widely used for other applications at ambient temperature environment. The ceramic material is preferably applied in powder form and is then melted or pressed together.
  • the material properties of the composition for the high temperature resistant electrical joint allow withstanding harsh environments inside a compressor, a gas turbine, a steam turbine or another kind of fluid flow machine while fulfilling the necessary function, i.e. electrical sealing of the inner core of mineral insulated under high temperature loading and harsh environment.
  • the high temperature resistant electrical joint connection based on ceramic formula can be used at higher temperatures and at the same time it provides better protection against moisture penetration.
  • the trace heating system comprises: a first mineral insulated cable extending inside the outer casing, the first mineral insulated cable having a first diameter, a second mineral insulated cable extending inside the outer casing, the second mineral insulated cable having a second diameter which is larger than the first diameter of the first mineral insulated cable, wherein the high temperature resistant electrical joint connects the second mineral insulated cable and the cable without mineral insulation.
  • Both the first and the second cable extend just inside the outer casing, only the cable without mineral insulation extends partly inside and partly outside the outer casing. The technical realization of the high temperature resistant electrical connection between the cable without mineral insulation and the mineral insulated cable with the larger diameter proved to be easier in practice.
  • the high temperature resistant electrical joint is located inside the outer casing.
  • the electrical joint can be located either on the surface of the inner casing or in the gap between the outer and the inner casing.
  • the trace heating system comprises an electrical connector inside the outer casing connecting one cable without mineral insulation to another cable without mineral insulation.
  • the electrical connector can be any kind of an electro-mechanical device used to join the cables and create an electrical circuit. The usage of an electrical connector that is directly attached to the inner casing, to connect electrical wires coming from outside of fluid flow machine has a few advantages. In the first place it makes assembly and disassembly procedures of the inner casing with the electrical trace heating system easier.
  • the inner casing can be assembled as usual (no electrical cables are "hanging" around).
  • the outside cables can be attached to the inner casing cables by using the electrical connector.
  • the outside cables can be detached and removed first, after which the usual disassembly procedure can take place.
  • the fluid flow machine is turbine with horizontal joint frame e.g. compressor
  • the usage of the intermediate electrical connector allows easier roll-out of inner casing e.g. compressor vane carriers without rotor lift.
  • an electrical connector also simplifies repair and replacement procedures in service cases. Normally, the likelihood of damage, e.g. cable break, caused by vibration and/or relative movement between the inner and the outer casings is significantly higher at the transition area between the inner casing and the outer casing.
  • the cables including the connector parts that are directly installed at the inner casing can be attached and fixed in a way that would almost eliminate relative movements and with it the main source for potential damage.
  • the cables that are connected from outside to the ones at the inner casing can be relatively easy disconnected and replaced or repaired if necessary.
  • the high temperature resistant electrical joint and the electrical connector build together an electrical connection unit, in particular in form of a plug-in/plug-out connector.
  • the mineral insulation contains magnesia.
  • the mineral insulation of the at least one cable is composed of magnesia.
  • Magnesium oxide or magnesia belongs to the group of high-temperature ceramic materials. It has good electrical insulation properties at high temperatures and very good thermal conductivity.
  • first and the second mineral insulated cables are connected to each other using a welding joint. Both cables are made as inseparable parts due to special laser welded joint, which makes assembly and disassembly difficult.
  • a service opening is provided on the outer casing.
  • the service opening is used by an operator or an operating device to connect the cable without mineral insulation coming from outside the outer casing to the cables inside the outer casing.
  • the service opening can be used during installation as well as during service and maintenance.
  • FIG 1 shows a fluid flow machine 2, e.g. a compressor or a turbine of a gas or steam turbine plant which is not shown in the drawing.
  • the fluid flow machine 2 comprises an outer casing 4 and an inner casing 6. Between the outer casing 4 and the inner casing 6 there is a gap 8.
  • the fluid flow machine 2 comprises also a trace heating system 10 mounted on the surface of the inner casing 6 inside the outer casing 4.
  • the trace heating system 10 comprises a first mineral insulated cable 12, two second mineral insulated cables 14 connected to the ends of first mineral insulated cable 12 and two cables without mineral insulation 16 which are connected each to one of second mineral insulated cables 14.
  • the mineral insulation of the first and the second mineral insulated cables 14, 16 consists of magnesia (MgO).
  • the first and second mineral insulated cables 14, 16 extend only inside the outer casing 4.
  • the first mineral insulated cable 12 has a first diameter and the second mineral insulated cables 14 have a second diameter which is larger than the first diameter.
  • Both cables without mineral insulation 16 have a part 16a extending inside the outer casing 4 and another part 16b extending outside the outer casing 4.
  • the external ends of the cables without mineral insulation 16 are connected to a termination box 18.
  • each of the cables without mineral insulation 16 is connected to one of the second mineral insulated cables 14 by means of a high temperature resistant electrical joint 20.
  • the high temperature resistant electrical joint 20 is a welding joint sealed by silicon-based insulating ceramic material.
  • the high temperature resistant electrical joint 20 protects the connection between the cables without mineral insulation 16 and the second mineral insulated cables 14 from both heat and humidity.
  • the first and the second mineral insulated cables 12, 14 are connected to each other by means of another welding joint 22, which is not necessarily a high temperature resistant connection.
  • the embodiment of a trace heating system 10 according to FIG 2 differs from the embodiment according to FIG 1 by implementing an electrical connector 24 located inside the outer casing 4.
  • the electrical connector 24 connects one part of the cable without mineral insulation 16a to another part of the same cable 16b.
  • the high temperature resistant electrical joint 20 and the connector 24 build together an electrical connection unit 26.
  • a service opening 28 is provided on the outer casing 4.
  • the service opening 28 is used for access inside the outer casing 4 to connect the outer part 16b of the cable without mineral insulation 16 to the inner part 16a.
  • the transition between the inner casing 6 and the outer casing 4 is potentially subject to vibration fatigue due to harsh environment (air or steam high velocity flow). It is, therefore, the most susceptible to operation flaws.
  • the entire electrical cable circuit of the trace heating system 10, potentially including the inner casing 6, will need to be replaced. All wires or cables are made inseparable, so that the repair of only one segment of cables, e.g. only the second mineral insulated cables 14, is at present impossible. This is why both the assembly and the disassembly procedures create significant risk of damaging of system components such as wires, laser welded joints etc.
  • the electrical connector 24 is used in order to provide a more convenient way to lead the cables without mineral insulation 16 out of the outer casing 4 during installation or during maintenance.
  • the assembly sequence can be as follows:
EP18186484.4A 2018-07-19 2018-07-31 Système de chauffage de trace pour une machine d'écoulement de fluide Withdrawn EP3598845A1 (fr)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US201862700346P 2018-07-19 2018-07-19

Publications (1)

Publication Number Publication Date
EP3598845A1 true EP3598845A1 (fr) 2020-01-22

Family

ID=63244356

Family Applications (1)

Application Number Title Priority Date Filing Date
EP18186484.4A Withdrawn EP3598845A1 (fr) 2018-07-19 2018-07-31 Système de chauffage de trace pour une machine d'écoulement de fluide

Country Status (1)

Country Link
EP (1) EP3598845A1 (fr)

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2398359A (en) * 2003-02-17 2004-08-18 Tyco Thermal Controls Gmbh Electric heat tracing
US20140202764A1 (en) * 2013-01-18 2014-07-24 Thomas J. Restis Thermally isolating hermetic electrical feed-through
US20160134047A1 (en) * 2013-06-04 2016-05-12 Okazaki Manufacturing Method Structure for end of mi cable and method for producing the same

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2398359A (en) * 2003-02-17 2004-08-18 Tyco Thermal Controls Gmbh Electric heat tracing
US20140202764A1 (en) * 2013-01-18 2014-07-24 Thomas J. Restis Thermally isolating hermetic electrical feed-through
US20160134047A1 (en) * 2013-06-04 2016-05-12 Okazaki Manufacturing Method Structure for end of mi cable and method for producing the same

Similar Documents

Publication Publication Date Title
US7405358B2 (en) Splice for down hole electrical submersible pump cable
CN103994327B (zh) 防故障馈通设备
US9564265B2 (en) Coil assembly for a control rod driver having improved thermal resistance, and method for manufacturing the same
EP3394942B1 (fr) Interconnexion électrique résistante au feu
EP2800209B1 (fr) Connecteur de faisceau électrique
EP3598845A1 (fr) Système de chauffage de trace pour une machine d'écoulement de fluide
CN102361522A (zh) 一种变截面端头不发热铠装加热器及其制备方法
CN1325781C (zh) 控制系统电子部件遭受过热情况下的发动机自动保护系统
CN108132011A (zh) 一种防振耐高温结构位移传感器
JP5864270B2 (ja) 原子力プラント温度計測システムおよび原子力プラント計装システム
CN204741145U (zh) 工程机械设备电脑控制总成线束
EP1717822B1 (fr) Ensemble de traversee electrique hermetique basse tension
CN102818649A (zh) 拱顶热电偶及热风炉
CN101095203A (zh) 平均电压的电密封穿透结构
CN209823032U (zh) 矿物绝缘电缆组件
CN220018738U (zh) 温度测量装置
EP2602891A2 (fr) Couvercle hermétique pour connecteur électrique
CN110011111A (zh) 一种插头及使用该插头的耐辐照耐高温密封连接器组件
CN212363477U (zh) 一种ntc温度传感器封装结构
CN220190410U (zh) 一种防火电线
CN218333181U (zh) 一种耐高温型绝缘电力电缆
CN108292817A (zh) 用于海底应用的电连接总成
CN211958948U (zh) 一种工业用无火花型防爆电机
CN116481658A (zh) 温度测量装置
WO2023184965A1 (fr) Connecteur

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

AX Request for extension of the european patent

Extension state: BA ME

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 20200723