JP2010022160A

JP2010022160A - Expansion turbine braking apparatus

Info

Publication number: JP2010022160A
Application number: JP2008181856A
Authority: JP
Inventors: Akira Takaike; 明高池; Masaki Hirokawa; 昌樹弘川
Original assignee: Taiyo Nippon Sanso Corp
Current assignee: Taiyo Nippon Sanso Corp
Priority date: 2008-07-11
Filing date: 2008-07-11
Publication date: 2010-01-28

Abstract

<P>PROBLEM TO BE SOLVED: To continuously brake an expansion turbine even if there is something wrong with an inverter or a heat radiator to prevent an increase in the rotating speed of the expansion turbine more than necessary in an expansion turbine braking apparatus equipped with the expansion turbine, an induction machine, a converter, a capacitor, the inverter, the heat radiator, a backup power supply, and a controller. <P>SOLUTION: The expansion turbine braking apparatus includes an expansion turbine 6, an induction machine 5, a converter 1, a capacitor 2, an inverter 4, a heat radiator 3, a backup power supply 8, a controller 9, a first electromagnetic switch 10, a second electromagnetic switch 11, and a DC power supply 12. When the induction machine works as a power generator, if there is something wrong with the inverter or the heat radiator, the inverter and the induction machine are disconnected and a direct current is applied to the induction machine from the DC power supply to stop the rotation of the induction machine. Thereby, the rotation of the expansion turbine is braked and there is no chance of an increase in the rotating speed of the expansion turbine. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

この発明は、空気深冷分離装置、各種冷凍機などで使用される膨張タービンの非常時の制動装置に関する。 The present invention relates to an emergency braking device for an expansion turbine used in an air deep / cooling separation device, various refrigerators, and the like.

この種の膨張タービンの制動装置としては、従来から発電機を用いるものが知られている。このものは、膨張タービンの回転軸を発電機の回転子に連結し、膨張タービンで発生する動力を利用して発電を行い、電力を得るとともに膨張タービンの制動を行うものである。
現在、実用化されているものとしては、一部の大型空気分離装置に用いられ、発電された電力を該空気分離装置の補機類の電力として利用するものである。 As a braking device for this type of expansion turbine, one using a generator has been known. In this system, the rotating shaft of the expansion turbine is connected to the rotor of the generator, and power is generated using power generated by the expansion turbine to obtain electric power and brake the expansion turbine.
What is currently in practical use is used in some large air separation devices, and uses the generated power as the power of auxiliary equipment of the air separation device.

ところで、近年ではインバータ技術や商用電源の力率改善も可能な電力回生用コンバータ技術が向上している。このため、数ｋＷ〜数十ｋＷ程度の比較的容量の小さな小型膨張タービンにおいてもこの発電機制動の経済的メリットが得られることが予想される。 By the way, in recent years, inverter technology and converter technology for power regeneration that can improve the power factor of commercial power sources have been improved. For this reason, it is expected that the economic merit of this generator braking can be obtained even in a small expansion turbine having a relatively small capacity of about several kW to several tens of kW.

しかしながら、インバータ技術、コンバータ技術を利用した小型膨張タービンの発電機制動に際して、商用電源が停電した際やコンバータに異常が生じた際に、発電機が空転状態となって、膨張タービンに制動力が加わらなくなる事態が生じる。 However, when braking the generator of a small expansion turbine using inverter technology and converter technology, when the commercial power supply fails or when an abnormality occurs in the converter, the generator is idled and braking force is applied to the expansion turbine. There will be situations where it will not be added.

このように、膨張タービンに制動が効かない状態になると、小型膨張タービンではその羽根車が小型であり、その軸受が気体軸受、磁気軸受などで構成されている場合は特に、その回転系の慣性モーメントが極めて小さいものとなり、膨張タービンへの加圧気体の導入を停止するまでの僅かな時間でも、膨張タービンの回転数が急速に増速し、最悪の場合軸受や回転軸が損傷する危険性があった。 As described above, when the expansion turbine is not braked, the impeller of the small expansion turbine is small, and the inertia of the rotating system is particularly large when the bearing is composed of a gas bearing, a magnetic bearing, or the like. The moment when the moment becomes extremely small and the introduction of pressurized gas to the expansion turbine stops for a short time, the rotation speed of the expansion turbine increases rapidly, and in the worst case, the risk of damage to the bearings and rotating shaft was there.

このような問題点を解決するため、本出願人は、膨張タービンの制動装置を先に提案している（特願２００８−７９１５４）。
この制動装置は、図２に示すように、膨張タービン６と誘導機５とコンバータ１とコンデンサ２とインバータ４と放熱器３とバックアップ電源８と制御装置９を備えたものである。 In order to solve such problems, the present applicant has previously proposed a braking device for an expansion turbine (Japanese Patent Application No. 2008-79154).
As shown in FIG. 2, the braking device includes an expansion turbine 6, an induction machine 5, a converter 1, a capacitor 2, an inverter 4, a radiator 3, a backup power source 8, and a control device 9.

コンバータ１は、その入力端子が商用交流電源に接続され、例えば５０Ｈｚ、２００Ｖの三相交流が入力され、約２８０Ｖの直流に変換して出力する一種の整流器であり、かつインバータ４から出力される直流を商用電源と同相の三相交流に変換して、商用電源に送り返すものでもある。このコンバータ１の出力端子には並列にコンデンサ２が接続されている。 The converter 1 is connected to a commercial AC power source, and is a kind of rectifier that receives, for example, a three-phase AC of 50 Hz and 200 V, converts it to a DC of about 280 V, and outputs it from the inverter 4. It also converts direct current into three-phase alternating current in phase with the commercial power supply and sends it back to the commercial power supply. A capacitor 2 is connected in parallel to the output terminal of the converter 1.

このコンデンサ２は、例えば容量数十〜数百μＦ、耐圧６００Ｖの電解コンデンサなどからなるもので、コンバータ１あるいは後述するインバータ４からの直流を充電し、かつ放電するとともに、直流を平滑化する平滑コンデンサとしても機能するものである。
このコンデンサ２には、並列にインバータ４が接続されている。 The capacitor 2 is composed of, for example, an electrolytic capacitor having a capacity of several tens to several hundreds μF and a withstand voltage of 600 V. The capacitor 2 charges and discharges direct current from the converter 1 or an inverter 4 described later, and smoothes the direct current. It also functions as a capacitor.
An inverter 4 is connected to the capacitor 2 in parallel.

このインバータ４は、コンバータ１から入力される直流を例えば、０〜２０００Ｈｚ、数〜２００Ｖの三相交流に変換して誘導機５に送り、また、誘導機５で発電される例えば５０〜２０００Ｈｚ、２００〜３００Ｖの三相交流を２８０〜４２０Ｖの直流に変換し、常時誘導機５の固定子側に回転磁界を形成し続けるようにするもので、例えば可変電圧可変周波数制御型のものが用いられる。 The inverter 4 converts the direct current input from the converter 1 into, for example, 0 to 2000 Hz and several to 200 V three-phase alternating current and sends it to the induction machine 5, and the induction machine 5 generates power, for example, 50 to 2000 Hz. A three-phase alternating current of 200 to 300 V is converted into a direct current of 280 to 420 V, and a rotating magnetic field is continuously formed on the stator side of the induction machine 5. For example, a variable voltage variable frequency control type is used. .

誘導機５は、交流電動機と交流発電機の両方の機能を有するものであり、例えばかご形三相誘導電動(発電）機などが用いられる。この誘導機５の回転子は、膨張タービン６の回転軸と直結されており、膨張タービン６の回転軸と同じ回転数で回転するようになっている。 The induction machine 5 has functions of both an AC motor and an AC generator. For example, a cage three-phase induction motor (generator) is used. The rotor of the induction machine 5 is directly connected to the rotation shaft of the expansion turbine 6, and rotates at the same rotational speed as the rotation shaft of the expansion turbine 6.

膨張タービン６は、入口弁７を介して導入される加圧気体を羽根車（インペラー）に噴射して、これを回転させると同時に加圧気体を断熱膨張させてこの気体の温度を降下させて低温気体を得るとともに加圧気体が有しているエネルギーを羽根車の回転力に変換するものである。この例では、羽根車の直径が５０ｍｍ程度、回転数５万ｒｐｍ程度、容量１０ｋＷ程度の小容量のものが用いられている。 The expansion turbine 6 injects the pressurized gas introduced through the inlet valve 7 to the impeller and rotates it, and simultaneously adiabatically expands the pressurized gas to lower the temperature of the gas. While obtaining a low temperature gas, the energy which pressurized gas has is converted into the rotational force of an impeller. In this example, an impeller having a small capacity of about 50 mm, a rotational speed of about 50,000 rpm, and a capacity of about 10 kW is used.

また、前記コンデンサ２には、並列に放熱器３が接続されている。この放熱器３は、スイッチング素子３１とこのスイッチング素子３１に直列に接続された発熱抵抗体３２とから構成されている。スイッチング素子３１には、例えばトランジスタなどが用いられ、常時開（断）とされている。発熱抵抗体３２には、ニクロム抵抗体などが用いられる。 In addition, a radiator 3 is connected to the capacitor 2 in parallel. The heat radiator 3 includes a switching element 31 and a heating resistor 32 connected in series to the switching element 31. For example, a transistor or the like is used as the switching element 31 and is normally open (disconnected). For the heating resistor 32, a nichrome resistor or the like is used.

この放熱器３は、コンデンサ２が満充電となって端子間電圧が規定値を超えた時に、スイッチング素子３１が閉（接）となって、コンデンサ２から発熱抵抗体３２に流して、発熱抵抗体３２において熱として外部に放散してコンデンサ２に流れ込む過剰な電力を消費するものである。 In the radiator 3, when the capacitor 2 is fully charged and the voltage between the terminals exceeds a specified value, the switching element 31 is closed (contacted) and flows from the capacitor 2 to the heating resistor 32, thereby generating the heating resistor. In the body 32, excessive power is dissipated to the outside as heat and flows into the capacitor 2.

符号８は、バックアップ電源を示す。このバックアップ電源８は、商用電源が停電した際に、前記インバータ４、放熱器３に動作電力を供給して動作を継続するためのもので、蓄電池を搭載した市販品などを使用できる。 Reference numeral 8 denotes a backup power source. The backup power supply 8 is for supplying operating power to the inverter 4 and the radiator 3 when the commercial power supply fails, and a commercial product equipped with a storage battery can be used.

符号９は、制御装置を示す。この制御装置９は、以下に述べる制動装置全体の動作のうちインバータ４と放熱器３の動作を制御するものである。 Reference numeral 9 denotes a control device. The control device 9 controls the operations of the inverter 4 and the radiator 3 among the operations of the entire braking device described below.

以下に、この先願発明における制動装置の動作を説明する。
商用電源からの三相交流は、コンバータ１に送られ、コンバータ１で直流に変換されてコンデンサ２に一時的に蓄えられ平滑化され、インバータ４に送られ、ここで所定の周波数の三相交流に変換されて誘導機５に送られる。誘導機５は、この交流の入力により誘導電動機として回転を始め、膨張タービン６の回転軸を回転駆動する。 The operation of the braking device in the prior invention will be described below.
The three-phase alternating current from the commercial power source is sent to the converter 1, converted into direct current by the converter 1, temporarily stored in the capacitor 2, smoothed, and sent to the inverter 4, where the three-phase alternating current with a predetermined frequency is sent. And is sent to the induction machine 5. The induction machine 5 starts rotating as an induction motor by the input of the alternating current, and rotationally drives the rotation shaft of the expansion turbine 6.

膨張タービン６の回転数が規定値を達したならば、膨張タービン６の入口弁７を開として加圧気体を膨張タービン６に導入する。この後もインバータ４からは引き続き三相交流が誘導機５に送られ、その固定子側に回転磁界が形成され続けて電圧を誘起するため、誘導機５は発電機として機能し始める。 When the rotational speed of the expansion turbine 6 reaches a specified value, the inlet valve 7 of the expansion turbine 6 is opened and the pressurized gas is introduced into the expansion turbine 6. After this, three-phase alternating current is continuously sent from the inverter 4 to the induction machine 5, and a rotating magnetic field is continuously formed on the stator side to induce a voltage, so that the induction machine 5 starts to function as a generator.

誘導機５で発電された交流はインバータ４において直流に変換され、コンデンサ２に一時的に蓄えられ平滑化されてコンバータ１に送られ、ここで商用電源と同周波数、同位相の交流に変換されて商用電源に返されて、電力回生が行われる。 The alternating current generated by the induction machine 5 is converted into direct current by the inverter 4, temporarily stored in the capacitor 2, smoothed and sent to the converter 1, where it is converted to alternating current of the same frequency and phase as the commercial power source. Then, it is returned to the commercial power source and power regeneration is performed.

そして、商用電源が停電した場合あるいはコンバータ１に異常が生じた場合、上述の電力回生ができなくなるが、バックアップ電源８が直ちに機能して、インバータ４、放熱器３に動作に必要な電力が供給され続け、誘導機５の回転磁界と誘導機５の回転子との間の電磁誘導で界磁コイルに電圧が誘起されて発電し続けるので、膨張タービン６の制動が間断なく継続できる。誘導機５で発電された交流はインバータ４にて直流に変換され、コンデンサ２に充電され、満充電になると放熱器３により消費される。 When the commercial power supply fails or when an abnormality occurs in the converter 1, the above-described power regeneration cannot be performed, but the backup power supply 8 immediately functions to supply the inverter 4 and the radiator 3 with the power necessary for the operation. Since the voltage is continuously induced in the field coil by electromagnetic induction between the rotating magnetic field of the induction machine 5 and the rotor of the induction machine 5, the expansion turbine 6 can be continuously braked without interruption. The alternating current generated by the induction machine 5 is converted into direct current by the inverter 4, charged in the capacitor 2, and consumed by the radiator 3 when fully charged.

その後、膨張タービン６の入口弁７を閉止して加圧気体の導入を停止すると、誘導機５が発電領域から電動機駆動領域に切り替わり、コンデンサ２の電圧が低下し、規定の電圧以下になるとインバータ４および放熱器３の運転が停止する。 After that, when the inlet valve 7 of the expansion turbine 6 is closed and the introduction of the pressurized gas is stopped, the induction machine 5 is switched from the power generation region to the motor drive region, and the voltage of the capacitor 2 decreases, and when the voltage drops below the specified voltage, the inverter 4 and the radiator 3 are stopped.

膨張タービン６が電動機駆動領域になると、発電制動が働かなくとも膨張タービン６の回転数が増速せずに、フリーランの状態でゆっくりと減速して停止する。
このように、平常動作中に商用電源が停電した場合あるいはコンバータ１に異常が生じた場合でも、膨張タービン６の制動が持続されるので、膨張タービン６の羽根車の回転が急速に増速し、その軸受などが破損する危険性が生じることがない。 When the expansion turbine 6 enters the electric motor drive region, the rotational speed of the expansion turbine 6 does not increase even if power generation braking does not work, and the vehicle slowly decelerates and stops in a free-run state.
Thus, even when the commercial power supply fails during normal operation or when an abnormality occurs in the converter 1, the braking of the expansion turbine 6 is continued, so that the rotation of the impeller of the expansion turbine 6 increases rapidly. There is no risk of damage to the bearings.

この先願発明の制動装置にあっては、しかしながらインバータ４や放熱器３に異常が生じて、インバータ４から発電状態にある誘導機５への回転磁界形成用の交流の供給が停止すると、誘導機５が空転状態となり、膨張タービン６が制動力を失って回転数が急速に増加し、最悪の場合には膨張タービン６の回転軸や軸受が損傷する危険性が残っていた。
特開２０００−２４８１号公報 In the brake device of the prior invention, however, when an abnormality occurs in the inverter 4 or the radiator 3 and the supply of alternating current for forming a rotating magnetic field from the inverter 4 to the induction machine 5 in the power generation state is stopped, the induction machine 5 is in an idle state, the expansion turbine 6 loses the braking force, and the rotational speed rapidly increases. In the worst case, there remains a risk of damage to the rotating shaft and the bearing of the expansion turbine 6.
JP 2000-2481 A

よって、本発明における課題は、膨張タービンと誘導機とコンバータとコンデンサとインバータと放熱器とバックアップ電源と制御装置を備えた膨張タービン制動装置において、インバータまたは放熱器に異常が生じても膨張タービンの制動が維持され、膨張タービンの回転数がむやみに増速することがないようにすることにある。 Therefore, an object of the present invention is to provide an expansion turbine braking device including an expansion turbine, an induction machine, a converter, a capacitor, an inverter, a radiator, a backup power source, and a control device. The purpose of this is to maintain braking and to prevent the rotational speed of the expansion turbine from increasing unnecessarily.

かかる課題を解決するため、
請求項１にかかる発明は、膨張タービンと誘導機とコンバータとコンデンサとインバータと放熱器とバックアップ電源と制御装置と第１電磁開閉器と第２電磁開閉器と直流電源装置を備えた膨張タービン制動装置であって、
前記膨張タービンは、加圧気体を導入し断熱膨張させて回転軸に回転力を与えるものであり、
前記誘導機は、前記膨張タービンの回転軸に直結された回転子を有し、膨張タービンの回転軸を回転駆動する電動機となる一方、この膨張タービンの回転軸によって回転駆動されて発電機となるものであり、
前記コンバータは、商用電源からの交流を直流に変換して前記コンデンサに送るもの、あるいは商用電源からの交流を直流に変換して前記コンデンサに送る一方、前記膨張タービンによる発電が前記インバータで交直変換されて逆送された直流を商用交流に変換して商用電源に戻すものであり、
前記コンデンサは、前記コンバータと前記インバータで変換された直流を蓄えて平滑化するものであり、
前記インバータは、前記コンバータで変換された直流を交流に変換して前記誘導機に送り、この誘導機を電動機として機能させる一方、この誘導機が発電機として機能した際に発生する交流を直流に変換して前記コンデンサに送るものであり、
前記放熱器は、スイッチング素子と発熱抵抗体を備え、前記コンデンサが満充電となった時にスイッチング素子が作動して前記コンデンサの過電圧分を発熱抵抗体に流して熱として放散するものであり、
前記バックアップ電源は、商用電源が断となった際に、前記インバータと前記放熱器の前記スイッチング素子に動作電力を供給するものであり、
前記制御装置は、前記誘導機が発電機として機能している状態において、前記誘導機の界磁コイルに電圧を誘起し続け発電された電力を前記放熱器に流して熱として放散するように制御し、かつ前記インバータまたは放熱器に異常が生じた際にその異常信号を出力するものであり、
前記第１電磁開閉器は、前記制御装置からの異常信号に基づいて前記インバータと前記誘導機との接続を遮断するものであり、
前記第２電磁開閉器は、電圧検出手段による前記誘導機の残留電圧が予め設定した値以下に低下した際に前記誘導機と前記直流電源装置とを接続するものであり、
前記直流電源装置は、直流電源を備え、前記第２電磁開閉器が前記誘導機と前記直流電源装置とを接続すると、直流電源からの直流を前記誘導機に供給するものであり、
前記膨張タービンの発電制動ができなくなった際に、前記膨張タービンがむやみに増速しないように制動できることを特徴とする膨張タービン制動装置である。 To solve this problem,
The invention according to claim 1 is an expansion turbine brake comprising an expansion turbine, an induction machine, a converter, a capacitor, an inverter, a radiator, a backup power supply, a control device, a first electromagnetic switch, a second electromagnetic switch, and a DC power supply device. A device,
The expansion turbine introduces a pressurized gas and adiabatically expands to give a rotational force to the rotating shaft,
The induction machine has a rotor directly connected to the rotation shaft of the expansion turbine, and serves as an electric motor that rotationally drives the rotation shaft of the expansion turbine. On the other hand, the induction machine is rotationally driven by the rotation shaft of the expansion turbine to become a generator. Is,
The converter converts alternating current from a commercial power source into direct current and sends it to the capacitor, or converts alternating current from a commercial power source into direct current and sends it to the capacitor, while power generation by the expansion turbine is AC / DC converted by the inverter The reversely sent direct current is converted to commercial alternating current and returned to the commercial power supply.
The capacitor stores and smoothes the direct current converted by the converter and the inverter,
The inverter converts the direct current converted by the converter into alternating current and sends the alternating current to the induction machine to cause the induction machine to function as an electric motor, while the alternating current generated when the induction machine functions as a generator is converted to direct current. Converted and sent to the capacitor,
The radiator includes a switching element and a heating resistor, and when the capacitor is fully charged, the switching element is activated to dissipate the overvoltage of the capacitor through the heating resistor as heat,
The backup power supply supplies operating power to the inverter and the switching element of the radiator when a commercial power supply is cut off,
The control device is configured to continuously induce a voltage in the field coil of the induction machine and to dissipate the generated power as heat by flowing through the radiator while the induction machine functions as a generator. And when the abnormality occurs in the inverter or radiator, the abnormality signal is output,
The first electromagnetic switch is for disconnecting the connection between the inverter and the induction machine based on an abnormal signal from the control device,
The second electromagnetic switch connects the induction machine and the DC power supply device when a residual voltage of the induction machine by the voltage detection means decreases below a preset value.
The DC power supply device includes a DC power supply, and when the second electromagnetic switch connects the induction machine and the DC power supply device, the direct current from the DC power supply is supplied to the induction machine.
The expansion turbine braking device is characterized in that when the power generation braking of the expansion turbine becomes impossible, the expansion turbine can be braked so as not to increase speed unnecessarily.

請求項２にかかる発明は、前記電圧検出手段が、前記制御装置と前記直流電源装置のうち、少なくとも一方に備えられていることを特徴とする請求項１に記載の膨張タービン制動装置である。 The invention according to claim 2 is the expansion turbine braking device according to claim 1, wherein the voltage detecting means is provided in at least one of the control device and the DC power supply device.

請求項３にかかる発明は、膨張タービンと誘導機とコンバータとコンデンサとインバータと放熱器とバックアップ電源と制御装置と第１電磁開閉器と第２電磁開閉器と直流電源装置を備えた膨張タービン制動装置であって、
前記膨張タービンは、加圧気体を導入し断熱膨張させて回転軸に回転力を与えるものであり、
前記誘導機は、前記膨張タービンの回転軸に直結された回転子を有し、膨張タービンの回転軸を回転駆動する電動機となる一方、この膨張タービンの回転軸によって回転駆動されて発電機となるものであり、
前記コンバータは、商用電源からの交流を直流に変換して前記コンデンサに送るもの、あるいは商用電源からの交流を直流に変換して前記コンデンサに送る一方、前記膨張タービンによる発電が前記インバータで交直変換されて逆送された直流を商用交流に変換して商用電源に戻すものであり、
前記コンデンサは、前記コンバータと前記インバータで変換された直流を蓄えて平滑化するものであり、
前記インバータは、前記コンバータで変換された直流を交流に変換して前記誘導機に送り、この誘導機を電動機として機能させる一方、この誘導機が発電機として機能した際に発生する交流を直流に変換して前記コンデンサに送るものであり、
前記放熱器は、スイッチング素子と発熱抵抗体を備え、前記コンデンサが満充電となった時にスイッチング素子が作動して前記コンデンサの過電圧分を発熱抵抗体に流して熱として放散するものであり、
前記バックアップ電源は、商用電源が断となった際に、前記インバータと前記放熱器の前記スイッチング素子に動作電力を供給するものであり、
前記制御装置は、前記誘導機が発電機として機能している状態において、前記誘導機の界磁コイルに電圧を誘起し続け発電された電力を前記放熱器に流して熱として放散するように制御し、かつ前記インバータまたは放熱器に異常が生じた際にその異常信号を出力するものであり、
前記第１電磁開閉器は、前記制御装置からの異常信号に基づいて前記インバータと前記誘導機との接続を遮断するものであり、
前記第２電磁開閉器は、前記制御装置から前記第１電磁開閉器への開信号発信後予め設定した時間が経過した後に前記誘導機と前記直流電源装置とを接続するものであり、
前記直流電源装置は、直流電源を備え、前記第２電磁開閉器が前記誘導機と前記直流電源装置とを接続すると、直流電源からの直流を前記誘導機に供給するものであり、
前記膨張タービンの発電制動ができなくなった際に、前記膨張タービンがむやみに増速しないように制動できることを特徴とする膨張タービン制動装置である。 According to a third aspect of the present invention, there is provided an expansion turbine braking system comprising an expansion turbine, an induction machine, a converter, a capacitor, an inverter, a radiator, a backup power supply, a control device, a first electromagnetic switch, a second electromagnetic switch, and a DC power supply device. A device,
The expansion turbine introduces a pressurized gas and adiabatically expands to give a rotational force to the rotating shaft,
The induction machine has a rotor directly connected to the rotation shaft of the expansion turbine, and serves as an electric motor that rotationally drives the rotation shaft of the expansion turbine. On the other hand, the induction machine is rotationally driven by the rotation shaft of the expansion turbine to become a generator. Is,
The converter converts alternating current from a commercial power source into direct current and sends it to the capacitor, or converts alternating current from a commercial power source into direct current and sends it to the capacitor, while power generation by the expansion turbine is AC / DC converted by the inverter The reversely sent direct current is converted to commercial alternating current and returned to the commercial power supply.
The capacitor stores and smoothes the direct current converted by the converter and the inverter,
The inverter converts the direct current converted by the converter into alternating current and sends the alternating current to the induction machine to cause the induction machine to function as an electric motor, while the alternating current generated when the induction machine functions as a generator is converted to direct current. Converted and sent to the capacitor,
The radiator includes a switching element and a heating resistor, and when the capacitor is fully charged, the switching element is activated to dissipate the overvoltage of the capacitor through the heating resistor as heat,
The backup power supply supplies operating power to the inverter and the switching element of the radiator when a commercial power supply is cut off,
The control device is configured to continuously induce a voltage in the field coil of the induction machine and to dissipate the generated power as heat by flowing through the radiator while the induction machine functions as a generator. And when the abnormality occurs in the inverter or radiator, the abnormality signal is output,
The first electromagnetic switch is for disconnecting the connection between the inverter and the induction machine based on an abnormal signal from the control device,
The second electromagnetic switch connects the induction machine and the DC power supply device after a preset time has elapsed after the opening signal is transmitted from the control device to the first electromagnetic switch.
The DC power supply device includes a DC power supply, and when the second electromagnetic switch connects the induction machine and the DC power supply device, the direct current from the DC power supply is supplied to the induction machine.
The expansion turbine braking device is characterized in that when the power generation braking of the expansion turbine becomes impossible, the expansion turbine can be braked so as not to increase speed unnecessarily.

本発明によれば、インバータまたは放熱器に異常が生じた場合、この異常状態が制御装置を介して第１電磁開閉器に送られ、第１電磁開閉器が開となって、インバータと誘導機との接続が遮断される。すると、励磁電流が遮断され誘導機に印加される残留電圧が減衰し、この残留電圧が予め設定されていた値以下に低下したことを直流電源装置もしくは制御装置に備えられた電圧検出手段が検知し、第２電磁開閉器に閉信号を送って、直流電源装置の直流電源からの直流電流を誘導機に供給する。あるいは、第１電磁開閉器が開となってから所定の時間が経過した後、制御装置を介して第２電磁開閉器に閉信号を送って、直流電源装置の直流電源からの直流電流を誘導機に供給する。
これにより、内部の回転磁界との電磁誘導で回転していた誘導機に制動がかかり、膨張タービンの回転数が急速に増加することがなく、膨張タービンの回転軸や軸受が損傷するなどの恐れがなくなる。 According to the present invention, when an abnormality occurs in the inverter or the radiator, this abnormal state is sent to the first electromagnetic switch via the control device, the first electromagnetic switch is opened, and the inverter and induction machine are opened. Is disconnected. Then, the excitation voltage is cut off and the residual voltage applied to the induction machine is attenuated, and the voltage detection means provided in the DC power supply device or the control device detects that the residual voltage has dropped below a preset value. Then, a close signal is sent to the second electromagnetic switch to supply a direct current from the direct current power supply of the direct current power supply device to the induction machine. Alternatively, after a predetermined time has elapsed after the first electromagnetic switch is opened, a close signal is sent to the second electromagnetic switch via the control device to induce a direct current from the direct current power supply of the direct current power supply device. Supply to the machine.
As a result, the induction machine that has been rotated by electromagnetic induction with the internal rotating magnetic field is braked, the rotation speed of the expansion turbine does not increase rapidly, and the rotating shaft and bearings of the expansion turbine may be damaged. Disappears.

図１は、本発明の制動装置の例を示すもので、図２に示した先願発明の制動装置と同一構成部分には同一符号を付してその説明を省略する。 FIG. 1 shows an example of a braking device of the present invention. The same components as those of the braking device of the prior application shown in FIG.

この例の制動装置にあっては、インバータ４と誘導機５を接続する配線に、これを開閉する第１電磁開閉器１０が挿入されている。この第１電磁開閉器１０は、制御装置９から発せられる異常信号に基づいて開閉が制御されるもので、常時閉（接続）となっている。 In the braking device of this example, a first electromagnetic switch 10 that opens and closes the wiring that connects the inverter 4 and the induction machine 5 is inserted. The first electromagnetic switch 10 is controlled to open and close based on an abnormal signal issued from the control device 9 and is normally closed (connected).

符号１２は、直流電源装置を示す。この直流電源装置１２は、第２電磁開閉器１１を介して誘導機５に接続されている。直流電源装置１２は、蓄電池などの直流電源と誘導機５の電圧を検出する交流電圧計などの電圧検出手段とこの電圧検出手段で検出された電圧値が予め設定されていた値以下に低下したとき、詳しくは誘導機５の残留電圧と直流電源装置１２の直流出力が重なり合ってインバータ４やコンデンサ２などの耐電圧を越えることがないように誘導機５の残留電圧が予め設定した値以下に低下したときに、第２電磁開閉器１１に閉信号を送出する制御部を備えたものである。 Reference numeral 12 denotes a DC power supply device. The DC power supply device 12 is connected to the induction machine 5 via the second electromagnetic switch 11. In the DC power supply device 12, a voltage detection means such as an AC voltmeter for detecting the voltage of the DC power supply such as a storage battery and the induction machine 5, and a voltage value detected by the voltage detection means have dropped below a preset value. In detail, the residual voltage of the induction machine 5 is less than a preset value so that the residual voltage of the induction machine 5 and the DC output of the DC power supply device 12 do not overlap and exceed the withstand voltage of the inverter 4 and the capacitor 2. The controller includes a control unit that sends a closing signal to the second electromagnetic switch 11 when the voltage drops.

なお、誘導機５の電圧を検出する交流電圧計などの電圧検出手段とこの電圧検出手段で検出された電圧値が予め設定した値以下に低下したときに第２電磁開閉器１１に閉信号を送出する制御部は、制御装置９にあってもよい。
第２電磁開閉器１１は、常時開（断）となっており、直流電源装置１２の制御部もしくは制御装置９からの閉信号により閉（接続）となって、直流電源装置１１の直流電源からの直流が誘導機５に供給されるように構成されている。 A voltage detection means such as an AC voltmeter for detecting the voltage of the induction machine 5 and a close signal to the second electromagnetic switch 11 when the voltage value detected by the voltage detection means falls below a preset value. The control unit for sending may be in the control device 9.
The second electromagnetic switch 11 is normally open (disconnected), and is closed (connected) by a closing signal from the control unit of the DC power supply device 12 or the control device 9, and from the DC power supply of the DC power supply device 11. Is supplied to the induction machine 5.

以下、この制動装置の動作について説明する。
商用電源からの三相交流は、コンバータ１に送られ、コンバータ１で直流に変換されてコンデンサ２に一時的に蓄えられ平滑化され、インバータ４に送られ、ここで所定の周波数の三相交流に変換されて誘導機５に送られる。誘導機５は、この交流の入力により誘導電動機として回転を始め、膨張タービン６の回転軸を回転駆動する。 The operation of this braking device will be described below.
The three-phase alternating current from the commercial power source is sent to the converter 1, converted into direct current by the converter 1, temporarily stored in the capacitor 2, smoothed, and sent to the inverter 4, where the three-phase alternating current with a predetermined frequency is sent. And is sent to the induction machine 5. The induction machine 5 starts rotating as an induction motor by the input of the alternating current, and rotationally drives the rotation shaft of the expansion turbine 6.

そして、インバータ４または放熱器３に異常が生じた場合には、インバータ４からの誘導機５への三相交流の供給が停止し、誘導機５が発電機能を失って、空転状態となる。
この状態で膨張タービン６の入口弁７を緊急閉止しても、導入された加圧気体の膨張などによりその回転数が急速に増加して上述のような不具合が発生する。
本発明において、入口弁７には手動弁を使用してもよいが自動弁を採用することがこのましく、異常発生時には第１電磁開閉器１０を開とすると同時に入口弁７を閉とすることがより好ましい。 And when abnormality arises in the inverter 4 or the heat radiator 3, supply of the three-phase alternating current to the induction machine 5 from the inverter 4 stops, the induction machine 5 loses a power generation function, and will be in an idling state.
Even if the inlet valve 7 of the expansion turbine 6 is urgently closed in this state, the rotation speed thereof increases rapidly due to the expansion of the introduced pressurized gas, and the above-described problems occur.
In the present invention, a manual valve may be used as the inlet valve 7, but an automatic valve is preferably adopted. When an abnormality occurs, the first electromagnetic switch 10 is opened and the inlet valve 7 is closed at the same time. It is more preferable.

このため、この例の制動装置においては、次の制動操作が行われるようになっている。
インバータ４の過負荷または放熱器３の過熱などの異常は、インバータ４自体または放熱器３自体で検出されて、その異常信号が制御装置９に送られる。
制御装置９は、この異常信号に基づいて、直ちに第１電磁開閉器１０に開信号を送出して、第１電磁開閉器１０を開とし、インバータ４と誘導機５との接続を遮断する。 For this reason, in the braking apparatus of this example, the following braking operation is performed.
Abnormalities such as overload of the inverter 4 or overheating of the radiator 3 are detected by the inverter 4 itself or the radiator 3 itself, and the abnormality signal is sent to the control device 9.
Based on this abnormal signal, the control device 9 immediately sends an open signal to the first electromagnetic switch 10 to open the first electromagnetic switch 10 and disconnect the connection between the inverter 4 and the induction machine 5.

この遮断により、誘導機５に印加される残留電圧が減衰し、この残留電圧が予め設定されていた値以下に低下したことが直流電源装置１２内もしくは制御装置９内の電圧検出手段によって検出される。すると、直流電源装置１２内もしくは制御装置９内の制御部から第２電磁開閉器１１に閉信号が送られ、第２電磁開閉器１１が閉じられて直流電源装置１２の直流電源から直流が誘導機５に印加される。誘導機５の許容温度越えないよう、この直流の印加時間は数秒以内である。 By this interruption, the residual voltage applied to the induction machine 5 is attenuated, and it is detected by the voltage detection means in the DC power supply device 12 or the control device 9 that the residual voltage has dropped below a preset value. The Then, a close signal is sent from the control unit in the DC power supply device 12 or the control device 9 to the second electromagnetic switch 11, the second electromagnetic switch 11 is closed, and DC is induced from the DC power supply of the DC power supply device 12. Applied to the machine 5. The DC application time is within several seconds so that the allowable temperature of the induction machine 5 is not exceeded.

この直流は、そのマイナス側が誘導機５の例えばＶ相に、そのプラス側が同じくＵ相またはＷ相、あるいはその両方に流れるようになっている。このような直流の誘導機５への印加によって、それまで内部の回転磁界との電磁誘導により回転していた誘導機５は、直流印加による直流励磁によって制動トルクが生じるため、回転の上昇が阻止され、制動されて減速する。
これに伴って膨張タービン６の回転も制動されて減速することになる。
このように、平常動作中にインバータ４または放熱器３に異常が生じた場合でも、膨張タービン６の制動が持続されるので、膨張タービン６の羽根車の回転が急速に増速し、その軸受などが破損する危険性が生じることがない。 The direct current flows in the negative phase of the induction machine 5 such as the V phase, and the positive side of the direct current also flows in the U phase or the W phase, or both. By applying such direct current to the induction machine 5, the induction machine 5 that has been rotating by electromagnetic induction with the internal rotating magnetic field until now generates braking torque by direct current excitation by direct current application, so that the increase in rotation is prevented. Is braked and decelerated.
Along with this, the rotation of the expansion turbine 6 is also braked and decelerated.
In this way, even when an abnormality occurs in the inverter 4 or the radiator 3 during normal operation, the braking of the expansion turbine 6 is continued, so that the rotation of the impeller of the expansion turbine 6 rapidly increases, and the bearings thereof There is no risk of damage.

なお、図１に示した制動装置では、平常運転時に誘導機５で発電された電力は、コンバータ１において商用電源の周波数、位相に合致した交流として商用電源に戻して電力回生を行っているが、コンバータ１が商用電源からの交流を直流に変換する機能のみを有しているものである場合には、誘導機５で発電された電力を放熱器３により消費するようにすればよい。 In the braking device shown in FIG. 1, the electric power generated by the induction machine 5 during normal operation is returned to the commercial power source as alternating current that matches the frequency and phase of the commercial power source in the converter 1 to perform power regeneration. When the converter 1 has only a function of converting alternating current from a commercial power source into direct current, the power generated by the induction machine 5 may be consumed by the radiator 3.

また、本発明の他の実施形態では、制御装置９内もしくは直流電源装置１２内に電圧検出手段を設けずに、制御装置９から第１電磁開閉器１０に開信号が送出されてから、予め設定された時間、例えば０．０１〜０．５秒後に、図１のライン２１で示すように、制御装置９から第２電磁開閉器１１に閉信号が送出されて、第２電磁開閉器１１が閉じられ、直流電源装置１２から誘導機５に直流電流が送られるように構成しても良い。
あるいは、制御装置９からの前記開信号が送出されたことを示す信号を第２電磁開閉器１１に送り、この信号を第２電磁開閉器１１が受けて自ら前記設定時間後に閉となるように遅延動作するようにしてもよい。 In another embodiment of the present invention, a voltage detection means is not provided in the control device 9 or the DC power supply device 12, and an open signal is sent from the control device 9 to the first electromagnetic switch 10 in advance. After a set time, for example, 0.01 to 0.5 seconds, as shown by a line 21 in FIG. 1, a closing signal is sent from the control device 9 to the second electromagnetic switch 11, and the second electromagnetic switch 11. May be closed, and a direct current may be sent from the DC power supply device 12 to the induction machine 5.
Alternatively, a signal indicating that the open signal from the control device 9 has been sent is sent to the second electromagnetic switch 11 so that the second electromagnetic switch 11 receives this signal and closes itself after the set time. A delay operation may be performed.

本発明の膨張タービン制動装置の例を示す概略構成図である。It is a schematic block diagram which shows the example of the expansion turbine braking device of this invention. 先願発明の膨張タービン制動装置の例を示す概略構成図である。It is a schematic block diagram which shows the example of the expansion turbine braking device of prior application invention.

Explanation of symbols

１・・・コンバータ、２・・・コンデンサ、３・・・放熱器、４・・・インバータ、５・・・誘導機、６・・・膨張タービン、７・・・入口弁、８・・・バックアップ電源、９・・・制御装置、１０・・・第１電磁開閉器、１１・・・第２電磁開閉器、１２・・・直流電源装置。 DESCRIPTION OF SYMBOLS 1 ... Converter, 2 ... Condenser, 3 ... Radiator, 4 ... Inverter, 5 ... Induction machine, 6 ... Expansion turbine, 7 ... Inlet valve, 8 ... Backup power source, 9 ... control device, 10 ... first electromagnetic switch, 11 ... second electromagnetic switch, 12 ... DC power supply device.

Claims

An expansion turbine braking device comprising an expansion turbine, an induction machine, a converter, a capacitor, an inverter, a radiator, a backup power supply, a control device, a first electromagnetic switch, a second electromagnetic switch, and a DC power supply device,
The expansion turbine introduces a pressurized gas and adiabatically expands to give a rotational force to the rotating shaft,
The induction machine has a rotor directly connected to the rotation shaft of the expansion turbine, and serves as an electric motor that rotationally drives the rotation shaft of the expansion turbine. On the other hand, the induction machine is rotationally driven by the rotation shaft of the expansion turbine to become a generator. Is,
The converter converts alternating current from a commercial power source into direct current and sends it to the capacitor, or converts alternating current from a commercial power source into direct current and sends it to the capacitor, while power generation by the expansion turbine is AC / DC converted by the inverter The reversely sent direct current is converted to commercial alternating current and returned to the commercial power supply.
The capacitor stores and smoothes the direct current converted by the converter and the inverter,
The inverter converts the direct current converted by the converter into alternating current and sends the alternating current to the induction machine to cause the induction machine to function as an electric motor, while the alternating current generated when the induction machine functions as a generator is converted to direct current. Converted and sent to the capacitor,
The radiator includes a switching element and a heating resistor, and when the capacitor is fully charged, the switching element is activated to dissipate the overvoltage of the capacitor through the heating resistor as heat,
The backup power supply supplies operating power to the inverter and the switching element of the radiator when a commercial power supply is cut off,
The control device is configured to continuously induce a voltage in the field coil of the induction machine and to dissipate the generated power as heat by flowing through the radiator while the induction machine functions as a generator. And when the abnormality occurs in the inverter or radiator, the abnormality signal is output,
The first electromagnetic switch is for disconnecting the connection between the inverter and the induction machine based on an abnormal signal from the control device,
The second electromagnetic switch connects the induction machine and the DC power supply device when a residual voltage of the induction machine by the voltage detection means decreases below a preset value.
The DC power supply device includes a DC power supply, and when the second electromagnetic switch connects the induction machine and the DC power supply device, the direct current from the DC power supply is supplied to the induction machine.
An expansion turbine braking apparatus, wherein when the power generation braking of the expansion turbine becomes impossible, the expansion turbine can be braked so as not to increase speed unnecessarily.

The expansion turbine braking device according to claim 1, wherein the voltage detection means is provided in at least one of the control device and the DC power supply device.

An expansion turbine braking device comprising an expansion turbine, an induction machine, a converter, a capacitor, an inverter, a radiator, a backup power supply, a control device, a first electromagnetic switch, a second electromagnetic switch, and a DC power supply device,
The expansion turbine introduces a pressurized gas and adiabatically expands to give a rotational force to the rotating shaft,
The induction machine has a rotor directly connected to the rotation shaft of the expansion turbine, and serves as an electric motor that rotationally drives the rotation shaft of the expansion turbine. On the other hand, the induction machine is rotationally driven by the rotation shaft of the expansion turbine to become a generator. Is,
The converter converts alternating current from a commercial power source into direct current and sends it to the capacitor, or converts alternating current from a commercial power source into direct current and sends it to the capacitor, while power generation by the expansion turbine is AC / DC converted by the inverter The reversely sent direct current is converted to commercial alternating current and returned to the commercial power supply.
The capacitor stores and smoothes the direct current converted by the converter and the inverter,
The inverter converts the direct current converted by the converter into alternating current and sends the alternating current to the induction machine to cause the induction machine to function as an electric motor, while the alternating current generated when the induction machine functions as a generator is converted to direct current. Converted and sent to the capacitor,
The radiator includes a switching element and a heating resistor, and when the capacitor is fully charged, the switching element is activated to dissipate the overvoltage of the capacitor through the heating resistor as heat,
The backup power supply supplies operating power to the inverter and the switching element of the radiator when a commercial power supply is cut off,
The control device is configured to continuously induce a voltage in the field coil of the induction machine and to dissipate the generated power as heat by flowing through the radiator while the induction machine functions as a generator. And when the abnormality occurs in the inverter or radiator, the abnormality signal is output,
The first electromagnetic switch is for disconnecting the connection between the inverter and the induction machine based on an abnormal signal from the control device,
The second electromagnetic switch connects the induction machine and the DC power supply device after a preset time has elapsed after the opening signal is transmitted from the control device to the first electromagnetic switch.
The DC power supply device includes a DC power supply, and when the second electromagnetic switch connects the induction machine and the DC power supply device, the direct current from the DC power supply is supplied to the induction machine.
An expansion turbine braking apparatus, wherein when the power generation braking of the expansion turbine becomes impossible, the expansion turbine can be braked so as not to increase speed unnecessarily.