JP3153867B2 - Steam generator - Google Patents
Steam generatorInfo
- Publication number
- JP3153867B2 JP3153867B2 JP08450590A JP8450590A JP3153867B2 JP 3153867 B2 JP3153867 B2 JP 3153867B2 JP 08450590 A JP08450590 A JP 08450590A JP 8450590 A JP8450590 A JP 8450590A JP 3153867 B2 JP3153867 B2 JP 3153867B2
- Authority
- JP
- Japan
- Prior art keywords
- heat
- heat transfer
- heat storage
- transfer tube
- steam
- 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.)
- Expired - Lifetime
Links
Description
【発明の詳細な説明】 〔産業上の利用分野〕 本発明は、蒸気使用量が大きく変動する場合に好適な
蒸気発生装置に関する。DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a steam generator suitable for a case where the amount of used steam fluctuates greatly.
蒸気は、一般にボイラを使用し、化石燃料の燃焼、又
は電力によって水を加熱することによって、発生されて
いる。この蒸気は、加熱用、暖房用、殺菌用、洗浄用等
に利用される。Steam is commonly generated using boilers, burning fossil fuels, or heating water with electric power. This steam is used for heating, heating, sterilization, cleaning, and the like.
しかし、ボイラで代表される従来の蒸気発生装置は、
蒸気使用量が時間的に大きく変動するような運転方法に
ついては、配慮がされておらず、このような場合は、第
８図に示すような蒸気アキュムレータ52の追設が必要で
あった。このため、従来の蒸気発生装置は、大きさおよ
び価格の点で経済的な装置となっていなかった。特に、
殺菌用又は洗浄用の蒸気使用の場合は、極端な間歇的、
集中的な蒸気使用となっており、従来の蒸気発生装置で
は、特に経済的に問題があった。However, conventional steam generators represented by boilers are:
No consideration was given to an operation method in which the amount of steam used fluctuates greatly with time. In such a case, an additional steam accumulator 52 as shown in FIG. 8 was required. For this reason, the conventional steam generator has not been an economical device in terms of size and price. In particular,
When using steam for sterilization or cleaning, extremely intermittent,
Intensive steam is used, and the conventional steam generator has a problem particularly economically.
たとえば、130℃〜150℃で数十秒間加熱するような食
品の殺菌、数分間加熱すような食品容器や試験用サンプ
リング容器等の殺菌に蒸気を使用するような短期間の蒸
気使用においては、特に、大容量の蒸気アキュムレータ
52を設置することとなり、消費蒸気量に対して大がかり
な装置となっていた。また、第８図において蒸気57の供
給を行わない時間も蒸気アキュムレータ52へ蒸気56を供
給する必要からボイラ51を運転する必要があった。この
蒸気アキュムレータ52内は高温高圧の温水・蒸気を保有
する必要から、運転操作においては安全上についても十
分注意を払う必要があった。For example, in the use of steam for a short period of time such as sterilizing food such as heating at 130 ° C. to 150 ° C. for several tens of seconds and using steam for sterilizing food containers and test sampling containers that are heated for several minutes, In particular, large capacity steam accumulators
52 were installed, and it was a large-scale device for the amount of steam consumed. In addition, in FIG. 8, the boiler 51 must be operated even during the time when the supply of the steam 57 is not performed since the steam 56 must be supplied to the steam accumulator 52. Since the steam accumulator 52 needs to hold high-temperature and high-pressure hot water / steam, it is necessary to pay sufficient attention to safety in operation.
この問題を解決する手段として、従来においても蓄熱
材を用いてその中に加熱源及び水が導入される伝熱管が
配設された蒸気発生器がある（実願昭63−125986号）。
しかし、この蓄熱材を用いた蒸気発生器は、蓄熱温度、
蓄熱方法、出熱方法が明確でなく、また、十分な蓄熱及
び出熱が行われない欠点があった。例えば、蓄熱材に代
表的なマグネシアを用いたものは、蓄熱時においては、
加熱源である電気ヒータで蓄熱材を加熱する際、該電気
ヒータから蓄熱材へ熱が十分な速度で伝わらず、電気ヒ
ータが焼損する問題が見られた。また、出熱時におい
て、蓄熱材が十分な高温であっても、蒸気を発生できな
くなる問題が見られた。その理由は、蓄熱材とヒータ及
び蓄熱材と伝熱管の間に空気層が生じており、この空気
層によってヒータと蓄熱材の間の熱伝達が低下している
ことによると思われる。As a means for solving this problem, there has been a steam generator in which a heat storage material is used and a heat source and a heat transfer tube into which water is introduced are disposed (Japanese Utility Model Application No. 63-12586).
However, a steam generator using this heat storage material has a heat storage temperature,
There were drawbacks that the heat storage method and heat output method were not clear, and that sufficient heat storage and heat output were not performed. For example, when using typical magnesia for the heat storage material,
When the heat storage material is heated by the electric heater which is a heating source, there is a problem that heat is not transmitted from the electric heater to the heat storage material at a sufficient speed and the electric heater is burned. In addition, at the time of heat output, there was a problem that steam could not be generated even if the heat storage material was at a sufficiently high temperature. It is considered that the reason is that an air layer is formed between the heat storage material and the heater and between the heat storage material and the heat transfer tube, and this air layer reduces heat transfer between the heater and the heat storage material.
上記従来技術のうち、ボイラで代表される蒸気発生装
置は殺菌用等の蒸気使用量が時間的に大きく変動する使
用に対して十分な配慮がされておらず、このような使用
の蒸気発生装置としては、経済上の問題があった。また
蓄熱材を用いた蒸気発生装置は蓄熱材内の熱移動につい
て十分な配慮がされておらず、十分な蓄熱・出熱が行わ
れない問題があった。Among the above prior arts, steam generators represented by boilers have not been given sufficient consideration for use in which the amount of steam used for sterilization and the like greatly fluctuates with time. As such, there was an economic problem. Further, the steam generator using the heat storage material has a problem in that sufficient consideration is not given to heat transfer in the heat storage material, and sufficient heat storage and heat output are not performed.
つまり、従来技術の蒸気発生器は、蒸気使用量が時間
的に大きく変動する殺菌用、洗浄用等の蒸気発生装置に
は適しない問題があった。In other words, the conventional steam generator has a problem that it is not suitable for a steam generator for sterilization, cleaning, or the like, in which the amount of used steam varies greatly with time.
本発明の目的は、蓄熱材とヒータ又は伝熱管と間の熱
移動を促進し、時間的に大きく変動する蒸気使用におい
ても、十分な蓄熱・出熱が行われる蓄熱材を用いた蒸気
発生装置を提供することにある。An object of the present invention is to promote a heat transfer between a heat storage material and a heater or a heat transfer tube, and to use a heat storage material capable of sufficiently storing and outputting heat even when using steam that fluctuates greatly over time. Is to provide.
上記目的は、蓄熱材とヒータ及び伝熱管との間に生じ
る空気層に、液相の熱媒体を充填させることにより、達
成される。The above object is achieved by filling a liquid-phase heat medium into an air layer generated between a heat storage material and a heater and a heat transfer tube.
すなわち、本発明は、マグネシアを主成分とする固体
蓄熱材と、該固体蓄熱材に熱を供給する電気ヒータと、
前記固体蓄熱材から受熱する関係に配設される伝熱管と
を容器内に収納し、容器の外部から前記伝熱管に水を通
流して蒸気を発生するようにしてなる蒸気発生装置にお
いて、硫酸塩と亜硫酸塩の少なくと１つを含んで構成さ
れ、蓄熱温度域で液体に相変化する熱媒体を前記容器に
収納してなることを特徴とする。That is, the present invention provides a solid heat storage material mainly composed of magnesia, an electric heater for supplying heat to the solid heat storage material,
In a steam generator configured to house a heat transfer tube disposed in a relationship to receive heat from the solid heat storage material in a container, and to generate steam by flowing water from the outside of the container to the heat transfer tube, sulfuric acid A heat medium which contains at least one of a salt and a sulfite and which changes into a liquid in a heat storage temperature range is stored in the container.
また、熱媒体は、硝酸ナトリウム、亜硝酸ナトリウム
及び硝酸カリウムの混合物、又は、硝酸ナトリウム及び
硝酸カリウムの混合物であることが好ましい。The heat medium is preferably a mixture of sodium nitrate, sodium nitrite and potassium nitrate, or a mixture of sodium nitrate and potassium nitrate.
前記蒸気発生装置において、蓄熱槽出口側の伝熱管外
表面に伝熱フィンが設けられ、伝熱管の単位長さ当りの
伝熱面積は蓄熱槽出口側が蓄熱槽入口側より大きく形成
されているものがよい。また、伝熱管はCrが14重量％以
上、Ｃが0.03重量％以下のオーステナイト系ステンレス
鋼であるものがよい。また、蓄熱槽入口の伝熱管内部が
二重管に形成されているものがよい。In the steam generator, the heat transfer fins are provided on the outer surface of the heat transfer tube on the outlet side of the heat storage tank, and the heat transfer area per unit length of the heat transfer tube is formed such that the outlet side of the heat storage tank is larger than the inlet side of the heat storage tank. Is good. The heat transfer tube is preferably made of austenitic stainless steel containing 14% by weight or more of Cr and 0.03% by weight or less of C. It is preferable that the inside of the heat transfer tube at the inlet of the heat storage tank is formed as a double tube.
蓄熱材の構成要素であるマグネシア等から成る第１物
質と電気ヒータ等の加熱源との間、及びこの第１物質と
伝熱管との隙間に生じている空気層に加熱されて液体と
なった熱媒体である第２物質が供給されると、この部分
の熱伝達は、熱媒体が供給されない場合の数倍〜数十倍
に増加する。The liquid was heated by the air layer formed between the first material made of magnesia or the like, which is a component of the heat storage material, and a heating source such as an electric heater, and the gap between the first material and the heat transfer tube. When the second substance as the heat medium is supplied, the heat transfer in this portion increases several times to several tens times as compared with the case where the heat medium is not supplied.
それによって、蓄熱時においては、ヒータから蓄熱材
への熱伝達が良好となるので、ヒータの焼損がなくな
る。また、出熱時においては、蓄熱材から伝熱管への熱
伝達が良好となるので、十分な熱量を蓄熱材から取り出
せるようになり、従来技術において見られた蓄熱材が高
温状態でも蒸気が発生しないという問題がなくなる。Thereby, at the time of heat storage, heat transfer from the heater to the heat storage material is improved, so that burnout of the heater is eliminated. Also, at the time of heat output, heat transfer from the heat storage material to the heat transfer tube becomes good, so that a sufficient amount of heat can be taken out from the heat storage material, and steam is generated even in the high-temperature state of the heat storage material seen in the prior art. The problem of not doing it disappears.
本発明の一実施例は、蓄熱材とヒータ及び蓄熱材と伝
熱管の間の空気層に、硝酸塩、亜硝酸塩を供給するもの
である。In one embodiment of the present invention, nitrate and nitrite are supplied to an air layer between a heat storage material and a heater and between the heat storage material and a heat transfer tube.
この蓄熱材を用いた蒸気発生装置は、第１図に示した
如く、蓄熱槽11及び膨張タンク18から主に構成される。
蓄熱槽11内には、電気ヒータ14及び伝熱管13が設置さ
れ、蓄熱材12の構成要素である固体の第１物質としてマ
グネシア、蓄熱温度域で液体となる第２物質すなわち熱
媒体として硝酸ナトリウム／亜硝酸ナトリウム／硝酸カ
リウムの混合物（俗称HITEC）又は硝酸ナトリウム／硝
酸カリウムの混合物（俗称DrawSalt）が充填されてい
る。The steam generator using this heat storage material is mainly composed of a heat storage tank 11 and an expansion tank 18 as shown in FIG.
In the heat storage tank 11, an electric heater 14 and a heat transfer tube 13 are provided, and magnesia is used as a solid first material which is a component of the heat storage material 12, and a second material which is liquid in a heat storage temperature range, that is, sodium nitrate is used as a heat medium. / A mixture of sodium nitrite / potassium nitrate (commonly known as HITEC) or a mixture of sodium nitrate / potassium nitrate (commonly known as DrawSalt).
本発明の一実施例に用いるHITECは、硝酸ナトリウ
ム、亜硝酸ナトリウム、硝酸カリウムの三成分の混合剤
であり、これら三成分の重量比率は、それぞれ6.9％,4
8.9％,44.2％，または、その近傍の値である。これら三
成分から成るHITECは、融点が142℃、熱分解開始温度が
約600℃である。上記三成分の重量比率が上記数値より
ずれると、融点が次第に上昇し、熱分解温度が次第に低
下する。極端な場合として、硝酸ナトリウム、亜硝酸ナ
トリウムまたは硝酸カリウムの単一成分にすると、融点
は、それぞれ、308℃、270℃、333℃となる。また、熱
分解開始温度は、それぞれ、380℃、320℃、333℃とな
る（共立出版、化学大辞典より）。したがって、HITEC
のように上記三成分の混合剤にすると、単一成分より、
融点が130℃以上低下し、熱分解開始温度が約330℃上昇
する。HITEC used in one embodiment of the present invention is a mixture of three components of sodium nitrate, sodium nitrite, and potassium nitrate. The weight ratios of these three components are 6.9% and 4%, respectively.
It is 8.9%, 44.2%, or a value near that. HITEC composed of these three components has a melting point of 142 ° C and a thermal decomposition onset temperature of about 600 ° C. If the weight ratio of the three components deviates from the above values, the melting point gradually increases, and the thermal decomposition temperature gradually decreases. In extreme cases, a single component of sodium nitrate, sodium nitrite or potassium nitrate has melting points of 308 ° C, 270 ° C, and 333 ° C, respectively. The thermal decomposition onset temperatures are 380 ° C., 320 ° C., and 333 ° C., respectively (from Kyoritsu Shuppan, Chemical Dictionary). Therefore, HITEC
When a mixture of the above three components is used as in
The melting point decreases by 130 ° C or more, and the thermal decomposition onset temperature increases by about 330 ° C.
本発明の一実施例の第２物質（熱媒体）にHITECを用
いるとこの熱媒体は142℃から約600℃の範囲で、安定し
た液体状態にあって、蓄熱材ヒータ及び蓄熱材と伝熱管
との間の空気槽を埋めることができる。これにより、こ
の部分の熱伝達が良好となって間歇的、集中的な使用と
なる殺菌用等の蒸気使用に応えることができる。殺菌用
には、150℃程度（圧力:5ata）の蒸気を使用することか
ら、150℃以上の温度域で液体となるHITECは、有効な熱
媒体となりえる。When HITEC is used as the second substance (heat medium) in one embodiment of the present invention, the heat medium is in a stable liquid state in the range of 142 ° C. to about 600 ° C., and the heat storage material heater and the heat storage material and the heat transfer tube The air tank between can be filled. As a result, the heat transfer in this portion is improved, and it is possible to respond to the use of steam for sterilization or the like which is used intermittently and intensively. For sterilization, steam at about 150 ° C (pressure: 5ata) is used, so HITEC, which becomes liquid at a temperature range of 150 ° C or more, can be an effective heat medium.
熱媒体としては、ダウサムで代表される有機系熱媒体
がよく知られている。しかし、この有機系熱媒体は350
〜400℃以上になると、熱分解が発生するため、蓄熱材
の温度は350〜400以下にする必要がある。As the heat medium, an organic heat medium represented by Dowsome is well known. However, this organic heat medium is 350
When the temperature exceeds 400 ° C., thermal decomposition occurs, so the temperature of the heat storage material needs to be 350 to 400 or less.
硝酸ナトリウムと硝酸カリウムの混合物（DRAW−SAL
T）もHITECと同様に硝酸塩であることから、HITECと同
等の温度特性を有している。Mixture of sodium nitrate and potassium nitrate (DRAW-SAL
Since T) is a nitrate like HITEC, it has the same temperature characteristics as HITEC.
上記蓄熱材12は、ヒータ14からの加熱によって高温と
なる。伝熱管13への通水は、蒸気発生の要求が生じたと
きに行われる。伝熱管13へ供給された水15は、高温の蓄
熱材12から加熱され、蒸気16となって排出される。The heat storage material 12 is heated to a high temperature by the heater 14. The flow of water to the heat transfer tubes 13 is performed when a request for steam generation occurs. The water 15 supplied to the heat transfer tube 13 is heated from the high-temperature heat storage material 12 and is discharged as steam 16.
水15の供給量によって蒸気16の乾き度、過熱度が変化
する。水15の供給量が、蓄熱材12からの加熱量に対し
て、少ないならば、発生蒸気16は加熱蒸気となる。水15
の供給量を増加するにしたがって、飽和蒸気、湿り蒸気
となる。The dryness and superheat of the steam 16 change depending on the supply amount of the water 15. If the supply amount of the water 15 is smaller than the heating amount from the heat storage material 12, the generated steam 16 becomes the heating steam. Water 15
As the supply amount of water increases, it becomes saturated steam and wet steam.
本発明の一実施例によれば、蓄熱材12とヒータ14及び
蓄熱材12と伝熱管13の間の空気層を第２物質が液体とな
った熱媒体が埋めるため、熱伝達が良好となる。このた
め、蓄熱時においては、蓄熱材12に対する急速加熱が可
能となる。また、出熱時においては、蓄熱材12から伝熱
管13への急速熱伝達が可能となる。According to one embodiment of the present invention, since the heat medium in which the second substance is liquid is filled in the air layer between the heat storage material 12 and the heater 14 and the air layer between the heat storage material 12 and the heat transfer tube 13, heat transfer is improved. . Therefore, during heat storage, rapid heating of the heat storage material 12 is possible. Further, at the time of heat output, rapid heat transfer from the heat storage material 12 to the heat transfer tube 13 becomes possible.
第２図に、本発明に係る蓄熱槽11内に熱媒体を供給し
た場合と供給しない場合の発生蒸気量の比較を示し、第
３図に、このときの蓄熱槽11内蓄熱材の温度変化を示
す。蓄熱材の容積は400であり、蓄熱温度は450℃、発
生蒸気の圧力は5ataで、蒸気流量は50kg/hの条件におい
て比較した。第２図より本発明では50kg/hの蒸気流量で
140分間運転を継続できるのに対し、従来は３分間で蒸
気流量が低下してしまうことがわかる。また、第３図よ
り、本発明では蓄熱材の熱が有効に使われたことが解
る。すなわち、蓄熱槽内に熱媒体を供給すると蒸気発生
量を数十倍増加できる。FIG. 2 shows a comparison between the amount of generated steam when the heat medium is supplied and the case where the heat medium is not supplied into the heat storage tank 11 according to the present invention. FIG. 3 shows the change in temperature of the heat storage material in the heat storage tank 11 at this time. Is shown. The volume of the heat storage material was 400, the heat storage temperature was 450 ° C, the generated steam pressure was 5ata, and the steam flow rate was 50 kg / h. According to FIG. 2, in the present invention, at a steam flow rate of 50 kg / h,
It can be seen that while the operation can be continued for 140 minutes, the steam flow rate conventionally decreases in 3 minutes. FIG. 3 shows that the heat of the heat storage material was effectively used in the present invention. That is, when a heat medium is supplied into the heat storage tank, the amount of generated steam can be increased by several tens of times.
本発明の他の実施例を第４図に示す。本実施例は、伝
熱管の伝熱面積を水の流れ方向にしたがって、伝熱フィ
ン20等の設置により、増加させるようにするものであ
る。伝熱面積の増加は、連続的でもステップ状に変化し
てもよい。FIG. 4 shows another embodiment of the present invention. In the present embodiment, the heat transfer area of the heat transfer tube is increased by installing the heat transfer fins 20 and the like in accordance with the flow direction of water. The increase in the heat transfer area may be continuous or change stepwise.
本実施例の効果は、蓄熱材12に生じる温度分布の大き
な偏差（下流側が高温になりやすい）をなくし、これに
より、蓄熱材12からの加熱によって発生する蒸気量を増
加することができる。The effect of the present embodiment is to eliminate a large deviation in the temperature distribution generated in the heat storage material 12 (the downstream side is likely to become high temperature), thereby increasing the amount of steam generated by heating from the heat storage material 12.
伝熱管13に供給された水15は、蓄熱材12から加熱さ
れ、順次温水、湿り蒸気、乾き蒸気と変化しながら昇温
する。このため、伝熱面積が一定の場合は、蓄熱材12か
らの加熱量は、水の流れにしたがって減少し、蓄熱材12
の温度分布に大きな偏差が生じる。上記実施例では下流
側程伝熱性が高い構造であるため、この偏差が縮少す
る。そして、蓄熱材12の平均温度が従来技術より低温ま
で、蒸気16の発生が可能となるため、従来技術よりも多
くの蒸気発生が可能となる。The water 15 supplied to the heat transfer tube 13 is heated from the heat storage material 12, and rises in temperature while sequentially changing to hot water, wet steam, and dry steam. Therefore, when the heat transfer area is constant, the amount of heating from the heat storage material 12 decreases with the flow of water, and the heat storage material 12
Large deviation occurs in the temperature distribution. In the above embodiment, since the heat transfer property is higher toward the downstream side, the deviation is reduced. Further, since the steam 16 can be generated until the average temperature of the heat storage material 12 is lower than that in the conventional technology, more steam can be generated than in the conventional technology.
第５図に伝熱管13にフィン20を付け、水の流れ方向に
したがって、伝熱管の単位流さ当りの伝熱面積を３段階
に変化したときの、蓄熱材12の温度変化の一例を示す。
フィンなしの上流側は伝熱管1cm当たりの伝熱面積が3.1
4cm2であり、粗にフィンを設置した中間部は伝熱面積が
6.28cm2であり、密にフィンを設置した下流側は9.54cm2
である。FIG. 5 shows an example of the temperature change of the heat storage material 12 when the fins 20 are attached to the heat transfer tube 13 and the heat transfer area per unit flow of the heat transfer tube is changed in three stages according to the flow direction of water.
On the upstream side without fins, the heat transfer area per cm of heat transfer tube is 3.1
4 cm 2 and the heat transfer area is
It is 6.28cm 2, downstream installed the fins densely 9.54Cm 2
It is.
その結果、図示のとおり、フィン20を付けると伝熱管
入口近傍の温度と出口近傍の温度差は縮少し（一点鎖
線）、また、平均温度も約70℃低下した（同図ａとｂと
の差）。そして、蒸気発生量は25％増加した。なお、こ
のときの蓄熱槽の条件は、第２図、第３図と変わらな
い。As a result, as shown in the figure, when the fins 20 were attached, the temperature difference between the temperature near the inlet of the heat transfer tube and the temperature near the outlet was reduced (dashed line), and the average temperature was also reduced by about 70 ° C. (see FIGS. difference). And steam production increased by 25%. The conditions of the heat storage tank at this time are the same as those shown in FIGS.
本発明の他の実施例は、伝熱管の耐熱衝撃性を向上す
るため、伝熱管の材質を選択するものである。つまり、
伝熱管材質の主成分である鉄への添加成分元素を適宜選
択するものである。添加成分として、クロムが14重量％
以上、炭素が0.03重量％以下であるとよい。クロムは30
重量％以上になるとコストアップになるので、それ以下
とするのがよい。また、他に、ニッケルを80重量％以
下，ケイ素を３重量％以下，マンガンを５％以下，リン
を１％以下，イオウを１％以下，モリブデンを５％以
下，チタンを５％以下，ニオブを１％以下のうち複数の
成分を含むとよい。そして、この伝熱管はオーステナイ
ト系のステンレスであると熱衝撃に強い組織となるので
よい。In another embodiment of the present invention, the material of the heat transfer tube is selected in order to improve the thermal shock resistance of the heat transfer tube. That is,
The additive element to be added to iron, which is the main component of the heat transfer tube material, is appropriately selected. 14% by weight chromium as an additional component
As described above, the carbon content is preferably 0.03% by weight or less. Chrome is 30
If the content is more than the weight%, the cost is increased. In addition, other than 80% by weight of nickel, 3% by weight or less of silicon, 5% or less of manganese, 1% or less of phosphorus, 1% or less of sulfur, 5% or less of molybdenum, 5% or less of titanium, and niobium. May contain a plurality of components out of 1% or less. If the heat transfer tube is made of austenitic stainless steel, it may have a structure resistant to thermal shock.
この実施例によれば、蓄熱材からの加熱により高温と
なった伝熱管へステップ状に水を供給しても伝熱管には
割れが生じなくなる。According to this embodiment, even if water is supplied stepwise to the heat transfer tube heated to a high temperature by heating from the heat storage material, the heat transfer tube does not crack.
上記した材質の伝熱管として、JIS−G3463で規定され
たSUS304LTB（Ｃ＜0.03wt％、Si＜1.00wt％,Mn＜2.00wt
％,P＜0.04wt％,S＜0.030wt％,Ni:9.00〜13.00wt％,Cr:
18,00〜20,00wt％）を用い、蓄熱温度が600℃におい
て、伝熱管内へ水を供給したときは、伝熱管に割れが生
じなかった。しかし、上記した条件を満たさない伝熱熱
管であるJIS−G3462で規定のSTB20（C:0.10〜0.20wt％,
Si:0.10〜0.5wt％,Mn:0.30〜0.60wt％,P＜0.035wt％,S
＜0.035wt％,Cr:0.50〜0.80wt％,No:0.40〜0.65wt％）
を用いた場合は、伝熱管に割れが生じた。SUS304LTB specified in JIS-G3463 (C <0.03wt%, Si <1.00wt%, Mn <2.00wt)
%, P <0.04wt%, S <0.030wt%, Ni: 9.00 ~ 13.00wt%, Cr:
When water was supplied into the heat transfer tube at a heat storage temperature of 600 ° C., no crack occurred in the heat transfer tube. However, STB20 (C: 0.10 to 0.20 wt%, specified in JIS-G3462, which is a heat transfer tube that does not satisfy the above conditions)
Si: 0.10 to 0.5 wt%, Mn: 0.30 to 0.60 wt%, P <0.035 wt%, S
<0.035wt%, Cr: 0.50 ~ 0.80wt%, No: 0.40 ~ 0.65wt%)
When was used, cracks occurred in the heat transfer tube.
本発明の他の実施例を第６図に示す。本実施例は、伝
熱管13の水15の入口に、断熱管21を設置して二重管構造
にするものである。断熱管21には、セラミック，ニッケ
ルクロム鉄合金管等の耐熱衝撃性の材料を用いる。Another embodiment of the present invention is shown in FIG. In the present embodiment, a heat insulating tube 21 is provided at the inlet of the water 15 of the heat transfer tube 13 to form a double tube structure. The heat insulating tube 21 is made of a material having thermal shock resistance such as a ceramic or a nickel chromium iron alloy tube.
この実施例によれば、更に高温の蓄熱材からの加熱に
より高温となった伝熱管へステップ状に水を供給しても
伝熱管には割れが生じなくなった。According to this embodiment, even if water was supplied in a stepwise manner to the heat transfer tube heated to a high temperature by heating from the heat storage material having a higher temperature, cracks did not occur in the heat transfer tube.
伝熱管13に外径15.9mm、肉厚1.2mmのSUS304LTBを用
い、この伝熱管13内に断熱管として外径5mm、肉厚0.3mm
のニッケルクロム鉄合金管を挿入した。その結果、蓄熱
温度が700℃において、伝熱管13内へステップ状に水を
供給したが、伝熱管に割れが生じなかった。しかし、上
記同条件で、断熱管を挿入しない場合は、電熱管に割れ
が生じた。SUS304LTB with an outer diameter of 15.9 mm and a wall thickness of 1.2 mm is used for the heat transfer tube 13, and an outer diameter of 5 mm and a wall thickness of 0.3 mm are used as heat insulating tubes in the heat transfer tube 13.
Was inserted. As a result, when the heat storage temperature was 700 ° C., water was supplied stepwise into the heat transfer tubes 13, but no cracks occurred in the heat transfer tubes. However, when the heat insulating tube was not inserted under the same conditions, cracks occurred in the electric heating tube.
前記した蓄熱材、伝熱管、伝熱ファン及び断熱管を有
する蒸気発生装置において、この装置の蓄熱温度（最高
温度）を400〜600℃にする。蓄熱温度を高温にすると、
単位容積当りの蓄熱量が増加し、蒸気発生量を多くでき
るため、蓄熱槽を小型化できる。しかし、蓄熱温度で高
くなると、伝熱管の耐熱性、耐熱衝撃の問題、熱媒体の
耐熱性の問題から、無制限に高くはできない。In the above-described steam generator having the heat storage material, the heat transfer tube, the heat transfer fan, and the heat insulating tube, the heat storage temperature (maximum temperature) of the device is set to 400 to 600 ° C. When the heat storage temperature is increased,
Since the amount of heat storage per unit volume increases and the amount of generated steam can be increased, the size of the heat storage tank can be reduced. However, when the heat storage temperature increases, the temperature cannot be increased without limitation due to the heat resistance of the heat transfer tube, the problem of thermal shock, and the problem of the heat resistance of the heat medium.
伝熱管にSUS304LTBオーステナイトステンレス鋼管を
用いると、蓄熱温度は700℃程度にできるが、熱媒体にH
ITECを用いると蓄熱温度は600℃以下にする必要があ
る。When SUS304LTB austenitic stainless steel tube is used for the heat transfer tube, the heat storage temperature can be set to about 700 ° C.
When ITEC is used, the heat storage temperature must be 600 ° C or less.
入熱時のヒータ近傍の熱媒体の温度は、ヒータからの
加熱によって、熱媒体の平均温度より数十℃高くなるこ
とから、蓄熱温度は、熱媒体の耐熱温度より数十℃低い
温度が最高使用温度となる。なお、ヒータ近傍の蓄熱材
温度と蓄熱材の平均温度の差は、ヒータの熱負荷によっ
て変化することから、蓄熱温度は400〜600℃とするのが
妥当な温度である。Since the temperature of the heat medium near the heater at the time of heat input becomes several tens of degrees higher than the average temperature of the heat medium due to heating from the heater, the maximum heat storage temperature is several tens degrees lower than the heat-resistant temperature of the heat medium. Use temperature. Since the difference between the temperature of the heat storage material in the vicinity of the heater and the average temperature of the heat storage material changes depending on the heat load of the heater, it is appropriate to set the heat storage temperature to 400 to 600 ° C.
第７図に、本発明の一実施例及び他の一実施例である
蓄熱槽の蓄熱温度を変化したときの発生蒸気量を示す。
発生蒸気量は、蓄熱温度を高くするにしたがって増加す
る。FIG. 7 shows the amount of generated steam when the heat storage temperature of the heat storage tank according to one embodiment of the present invention and another embodiment is changed.
The amount of generated steam increases as the heat storage temperature increases.
しかし、蓄熱温度が550℃以上になるとHITECが分解
し、二酸化窒素が発生した。電気ヒータへの印加電圧を
200Vから140Vに低下し、入熱速度を10kwにしたところ、
蓄熱温度が570℃以下では、二酸化窒素を示す臭気がし
なかった。一方、印加電圧を200Vから280Vにし、入熱速
度を40kwにしたところ、蓄熱温度が510℃を越え、二酸
化窒素の臭気がした。However, when the heat storage temperature exceeded 550 ° C, HITEC was decomposed and nitrogen dioxide was generated. Voltage applied to the electric heater
When the heat input speed was reduced from 200V to 140V and the heat input speed was set to 10kw,
At a heat storage temperature of 570 ° C. or lower, there was no odor indicating nitrogen dioxide. On the other hand, when the applied voltage was changed from 200 V to 280 V and the heat input speed was set to 40 kw, the heat storage temperature exceeded 510 ° C., and the odor of nitrogen dioxide was found.
本発明によれば、時間的に大きく変動する蒸気使用に
おいても、十分な蓄熱・出熱が行われる蓄熱材を有する
蒸気発生装置を提供できる。したがって、本発明によれ
ば、蒸気発生量を時間的に大きく変動できる経済的な蒸
気発生装置を提供できる効果がえられる。Advantageous Effects of Invention According to the present invention, it is possible to provide a steam generator having a heat storage material capable of sufficiently storing and outputting heat even when using steam which fluctuates greatly with time. Therefore, according to the present invention, the effect of being able to provide an economical steam generator that can greatly vary the amount of generated steam over time is obtained.
第１図は、本発明の一実施例の蓄熱材を有する蒸気発生
装置の構成図、第２図及び第３図は、本発明の一実施例
の蓄熱材を有する蒸気発生装置の性能を示す図、第４図
は、本発明の他の一実施例である伝熱管にフィンを取り
付けた蓄熱材を有する蒸気発生装置の構成図、第５図
は、本発明の他の一実施例である伝熱管にフィンを取り
付けた効果を示す図、第６図は、本発明の他の一実施例
である伝熱管内への断熱管の取り付けを示す断面図、第
７図は、本発明の蓄熱材を有する蒸気発生装置の蓄熱温
度と蒸気発生量の関係を示す図、第８図は、従来技術の
一例であるボイラと蒸気アキュムレータを組み合わせた
負荷変動に適した蒸気発生装置の構成を示す図である。 11……蓄熱槽、12……蓄熱材、13……伝熱管、14……電
気ヒータ、20……伝熱フィン、21……断熱管。FIG. 1 is a configuration diagram of a steam generator having a heat storage material according to one embodiment of the present invention, and FIGS. 2 and 3 show the performance of a steam generator having a heat storage material according to one embodiment of the present invention. FIG. 4 is a configuration diagram of a steam generator having a heat storage material in which fins are attached to a heat transfer tube according to another embodiment of the present invention, and FIG. 5 is another embodiment of the present invention. FIG. 6 is a view showing the effect of attaching a fin to a heat transfer tube, FIG. 6 is a cross-sectional view showing the installation of a heat insulating tube in a heat transfer tube according to another embodiment of the present invention, and FIG. FIG. 8 is a diagram showing a relationship between a heat storage temperature and a steam generation amount of a steam generator having a material, and FIG. 8 is a diagram showing a configuration of a steam generator suitable for load fluctuation by combining a boiler and a steam accumulator as an example of the prior art It is. 11 ... heat storage tank, 12 ... heat storage material, 13 ... heat transfer tube, 14 ... electric heater, 20 ... heat transfer fin, 21 ... heat insulation tube.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 ▲高▼鷹 生男 広島県呉市宝町６番９号 バブコツク日 立株式会社呉工場内 (72)発明者 藤原 忠幸 東京都千代田区大手町２丁目６番２号 バブコツク日立株式会社内 (56)参考文献 特開 昭62−25640（ＪＰ，Ａ) 特開 昭61−205793（ＪＰ，Ａ) 特開 昭63−105363（ＪＰ，Ａ) 特開 昭63−190144（ＪＰ，Ａ) 特開 昭59−35786（ＪＰ，Ａ) 実開 昭60−10159（ＪＰ，Ｕ) (58)調査した分野(Int.Cl.7，ＤＢ名) F22B 1/00 F22B 1/18 F28D 20/00 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor ▲ Takao Ikuo 6-9 Takara-cho, Kure-shi, Hiroshima Babukotsukitsu Kure Factory (72) Inventor Tadayuki Fujiwara 2-6 Otemachi, Chiyoda-ku, Tokyo No. 2 in Bab Kok Hitachi, Ltd. (56) References JP-A-62-25640 (JP, A) JP-A-61-205793 (JP, A) JP-A-63-105363 (JP, A) JP-A-63 -190144 (JP, A) JP-A-59-35786 (JP, A) JP-A-60-10159 (JP, U) (58) Fields investigated (Int. Cl. 7 , DB name) F22B 1/00 F22B 1/18 F28D 20/00
Claims (5)
該固体蓄熱材に熱を供給する電気ヒータと、前記固体蓄
熱材から受熱する関係に配設される伝熱管とを容器内に
収納し、容器の外部から前記伝熱管に水を通流して蒸気
を発生するようにしてなる蒸気発生装置において、 硝酸塩と亜硫酸塩の少なくとも１つを含んで構成され、
蓄熱温度域で液体に相変化する熱媒体を前記容器に収納
してなる蒸気発生装置。1. A solid thermal storage material comprising magnesia as a main component,
An electric heater for supplying heat to the solid heat storage material and a heat transfer tube arranged to receive heat from the solid heat storage material are housed in a container, and water is passed from the outside of the container to the heat transfer tube to allow steam to flow. A steam generator configured to generate at least one of a nitrate and a sulfite,
A steam generator comprising a heat medium which changes into a liquid phase in a heat storage temperature region, which is housed in the container.
トリウム、亜硝酸ナトリウム及び硝酸カリウムの混合
物、又は、硝酸ナトリウム及び硝酸カリウムの混合物で
あることを特徴とする蒸気発生装置。2. The steam generator according to claim 1, wherein the heat medium is a mixture of sodium nitrate, sodium nitrite and potassium nitrate, or a mixture of sodium nitrate and potassium nitrate.
142℃以上、熱分解温度が600℃以上であることを特徴と
する蒸気発生装置。3. The method according to claim 1, wherein the heat medium has a melting point.
A steam generator characterized by a thermal decomposition temperature of at least 142 ° C and a thermal decomposition temperature of at least 600 ° C.
伝熱管の被加熱流体の出口側の外表面に伝熱フィンが設
けられ、伝熱管の単位長さ当りの伝熱面積が入口側より
大きく形成されてなる蒸気発生装置。4. A heat transfer fin according to claim 1, wherein a heat transfer fin is provided on an outer surface of the heat transfer tube on the outlet side of the fluid to be heated, and a heat transfer area per unit length of the heat transfer tube is on an inlet side. A steam generator formed larger.
伝熱管の被加熱流体の入口側は伝熱管内部が二重管に形
成されてなる蒸気発生装置。5. The steam generator according to claim 1, wherein the inside of the heat transfer tube is formed as a double tube at the inlet side of the fluid to be heated of the heat transfer tube.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP08450590A JP3153867B2 (en) | 1990-03-30 | 1990-03-30 | Steam generator |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP08450590A JP3153867B2 (en) | 1990-03-30 | 1990-03-30 | Steam generator |
Related Child Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP08610399A Division JP3165961B2 (en) | 1990-03-30 | 1999-03-29 | Heat storage device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH03282101A JPH03282101A (en) | 1991-12-12 |
| JP3153867B2 true JP3153867B2 (en) | 2001-04-09 |
Family
ID=13832502
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP08450590A Expired - Lifetime JP3153867B2 (en) | 1990-03-30 | 1990-03-30 | Steam generator |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3153867B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2016166705A (en) * | 2015-03-10 | 2016-09-15 | 三菱日立パワーシステムズ株式会社 | Solar heat storage device |
Families Citing this family (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2736579B2 (en) * | 1992-03-10 | 1998-04-02 | 中国電力株式会社 | Filling method of solid-liquid heat storage material |
| JP2736580B2 (en) * | 1992-03-10 | 1998-04-02 | 中国電力株式会社 | Thermal storage tank using solid-liquid mixed thermal storage material |
| JPH0771793A (en) * | 1993-09-01 | 1995-03-17 | Hokuriku Electric Power Co Inc:The | Heat accumulation type cooling and heating device using midnight electric power |
| JP2000097498A (en) * | 1998-09-25 | 2000-04-04 | Hokuriku Electric Power Co Inc:The | High temperature heat storage tank |
| JP2002022101A (en) * | 2000-07-11 | 2002-01-23 | Chiyoda Manufacturing Co Ltd | Saturated steam generating device |
| JP4538136B2 (en) * | 2000-07-11 | 2010-09-08 | サクラ精機株式会社 | Steam sterilizer |
| JP2002035090A (en) * | 2000-07-28 | 2002-02-05 | Chiyoda Manufacturing Co Ltd | Steam sterilizing method and device |
| JP4674011B2 (en) * | 2001-08-31 | 2011-04-20 | サクラ精機株式会社 | Saturated steam generator |
| JP2007521118A (en) | 2004-01-07 | 2007-08-02 | ノクシライザー，インコーポレイテッド | Sterilization system and equipment |
| US8017074B2 (en) | 2004-01-07 | 2011-09-13 | Noxilizer, Inc. | Sterilization system and device |
| JP2007032866A (en) * | 2005-07-22 | 2007-02-08 | Ishikawajima Inspection & Instrumentation Co | Heat storage tank |
| DE102006062069A1 (en) * | 2006-12-29 | 2008-07-03 | BSH Bosch und Siemens Hausgeräte GmbH | Steam generation device for e.g. steam baking oven, has pressure expansion unit arranged between feed pump and instantaneous water heater, and partially designed as container filled with gas or as one-sided closed plastic tube |
| JP5087667B2 (en) * | 2010-10-20 | 2012-12-05 | サクラ精機株式会社 | Saturated steam generator |
| JP2013199663A (en) * | 2012-03-23 | 2013-10-03 | Nisshin Steel Co Ltd | Austenitic stainless steel excellent in molten nitrate corrosion resistance, heat collection tube and heat accumulation system using molten nitrate as heat accumulation medium |
| JP2013224344A (en) * | 2012-04-19 | 2013-10-31 | Ihi Corp | Method for selecting heat storage material |
| JP2013224343A (en) * | 2012-04-19 | 2013-10-31 | Ihi Corp | Heat storage material, and heat storage system |
-
1990
- 1990-03-30 JP JP08450590A patent/JP3153867B2/en not_active Expired - Lifetime
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2016166705A (en) * | 2015-03-10 | 2016-09-15 | 三菱日立パワーシステムズ株式会社 | Solar heat storage device |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH03282101A (en) | 1991-12-12 |
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