JP2007333566A - Gas cavitation testing method and apparatus - Google Patents

Gas cavitation testing method and apparatus Download PDF

Info

Publication number
JP2007333566A
JP2007333566A JP2006165771A JP2006165771A JP2007333566A JP 2007333566 A JP2007333566 A JP 2007333566A JP 2006165771 A JP2006165771 A JP 2006165771A JP 2006165771 A JP2006165771 A JP 2006165771A JP 2007333566 A JP2007333566 A JP 2007333566A
Authority
JP
Japan
Prior art keywords
test
water
gas
cavitation
pump
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.)
Granted
Application number
JP2006165771A
Other languages
Japanese (ja)
Other versions
JP4793645B2 (en
Inventor
Tatsuo Fujiwara
龍雄 藤原
Tetsuji Shirae
哲次 白枝
Tetsuo Hori
哲郎 堀
Shoko Shimizu
勝公 清水
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.)
Shimizu Construction Co Ltd
Shimizu Corp
Original Assignee
Shimizu Construction Co Ltd
Shimizu Corp
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 Shimizu Construction Co Ltd, Shimizu Corp filed Critical Shimizu Construction Co Ltd
Priority to JP2006165771A priority Critical patent/JP4793645B2/en
Publication of JP2007333566A publication Critical patent/JP2007333566A/en
Application granted granted Critical
Publication of JP4793645B2 publication Critical patent/JP4793645B2/en
Expired - Fee Related legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Landscapes

  • Control Of Positive-Displacement Pumps (AREA)

Abstract

<P>PROBLEM TO BE SOLVED: To provide an effective and suitable testing method and apparatus by simplifying the generation condition of a gas cavitation for quantitatively grasping. <P>SOLUTION: A test pump 1 for circulating testing water is installed in a closed circulation system enabling circulation of testing water, an adjusting tank 5 adjusting the dissolved gas saturation in the testing water is installed on the suction side of the test pump. A gas-liquid separator 6 capable of visually observing the status of circulated testing water and measuring the degree of vacuum there is installed between the adjusting tank and the test pump. The dissolved gas saturation of the testing water is adjusting by the adjusting tank to operate the test pump, the occurrence status of gas cavitation in the circulated testing water is confirmed by the gas-liquid separator to measure the degree of vacuum at that time, and the limit of water pressure causing the gas cavitation is obtained taking the dissolved gas saturation as a parameter. The water temperature and suction flow velocity are taken as the other parameters. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

本発明は、ガスキャビテーションの発生条件を求めるための試験方法、およびそのための試験装置に関する。   The present invention relates to a test method for obtaining conditions for generating gas cavitation and a test apparatus therefor.

周知のように、ポンプにおいて生じるキャビテーションには、蒸気キャビテーションとガスキャビテーションの２つの現象がある。
蒸気キャビテーションは、ある温度の液体の圧力がその温度によって決まる飽和蒸気圧より低くなると、そこで液体が蒸発して蒸気の泡が生じることに起因する現象である。ポンプやプロペラの流れは場所により加速され圧力が低くなるので、常温でも液体が蒸発し気泡となり易く、それにより蒸気キャビテーションが発生し易くなる。
一方、ガスキャビテーションは、液体中の溶存ガスが過飽和になって液体中に溶出する現象である。通常、ガスキャビテーションは蒸気キャビテーションが発生する前に生じ、サイホン切れの原因となるとこが知られている。 As is well known, there are two phenomena of cavitation occurring in a pump: steam cavitation and gas cavitation.
Vapor cavitation is a phenomenon caused by the evaporation of liquid and the generation of vapor bubbles when the pressure of the liquid at a certain temperature falls below the saturated vapor pressure determined by the temperature. The flow of the pump and propeller is accelerated depending on the location and the pressure is lowered, so that the liquid is easily evaporated and bubbles are formed even at room temperature, thereby easily causing vapor cavitation.
On the other hand, gas cavitation is a phenomenon in which dissolved gas in a liquid is supersaturated and eluted into the liquid. It is known that gas cavitation usually occurs before steam cavitation occurs, causing siphon cuts.

それら２つのキャビテーションのうち、蒸気キャビテーションは気泡の崩壊時にきわめて高い圧力が発生し、それにより固体面が破壊（壊食）されたり、振動や騒音の原因となることが古くより知られており、そのため、ポンプについての一般的な性能試験（ＮＰＳＨＲ試験）においてもキャビテーション発生圧力についての試験が行われている。
一方、ガスキャビテーションはその現象こそ知られているが、それに関する研究はさほど進んでおらず、特に発生因子の定量的な把握はいまだできていない。従来より実施されているポンプの性能試験においてもガスキャビテーションについては全く考慮されておらず、上記のＮＰＳＨＲ試験においても完全脱気状態（つまり溶存ガスはない状態）で試験することが前提となっているので溶存ガスの影響を把握することはできない。
それ故、たとえば特許文献１に示されるような取水施設に設置される大規模な吸水装置等においては、ガスキャビテーションに起因するサイホン切れ等の限界を定量的に把握できておらず、したがってそのような施設の計画や設計は経験に頼って充分な安全率を見込んで行っているのが実状である。
特許第３５７９８２２号公報 Among these two cavitations, steam cavitation has long been known to cause extremely high pressure when bubbles are collapsed, causing the solid surface to break down (erosion) and cause vibration and noise. Therefore, a test for cavitation generation pressure is also performed in a general performance test (NPSHR test) for a pump.
On the other hand, gas cavitation is known for its phenomenon, but research on it has not progressed so far, and in particular, it has not been possible to quantitatively grasp the generation factors. Gas cavitation is not considered at all in the performance tests of pumps that have been performed conventionally, and it is assumed that the above-described NPSHR test is performed in a completely deaerated state (that is, in a state where there is no dissolved gas). Therefore, the effect of dissolved gas cannot be grasped.
Therefore, for example, in a large-scale water absorption device or the like installed in a water intake facility as shown in Patent Document 1, the limit of siphon breakage due to gas cavitation, etc. cannot be quantitatively grasped. The actual situation is that the planning and design of such facilities is based on experience and expects a sufficient safety factor.
Japanese Patent No. 3579822

このように、従来においてはガスキャビテーションについての定量的な把握ができておらず、したがってガスキャビテーションに対する有効な対策技術や防止技術も確立していないことから、ガスキャビテーションが問題となることが想定されるような施設の計画・設計に当たってはポンプをはじめとする装置類の設計や仕様決定に充分な安全率を見込まざるを得ず、そのことがその種の施設の建設コスト削減を阻む一因ともなっている。   As described above, gas cavitation is assumed to be a problem because quantitative cavitation about gas cavitation has not been achieved in the past, and effective countermeasure technology and prevention technology for gas cavitation have not been established. When planning and designing such a facility, it is necessary to expect a sufficient safety factor for the design and specification of equipment such as pumps, which is one of the factors that hinder the cost of construction of such facilities. ing.

上記事情に鑑み、本発明はガスキャビテーションの発生条件を定量的に把握するためのできる簡易にして有効適切な試験方法およびそのための試験装置を提供することを目的としている。   In view of the above circumstances, an object of the present invention is to provide a simple and effective test method and a test apparatus therefor, which can quantitatively grasp the generation conditions of gas cavitation.

請求項１記載の発明のガスキャビテーション試験方法は、試験水が循環可能な閉鎖循環系に、試験水を循環させるための試験ポンプを設置するとともに、該試験ポンプの吸込側に試験水中の溶存ガス飽和度を調整可能な調整槽を設置し、該調整槽と試験ポンプとの間には、循環中の試験水の状況を目視観測可能かつそこでの真空度を計測可能な気液分離器を設置しておき、前記調整槽により試験水の溶存ガス飽和度を調整して試験ポンプを運転し、循環中の試験水におけるガスキャビテーションの発生状況を前記気液分離器により確認してその時点の真空度を計測することによって、ガスキャビテーションが発生する限界の水圧を試験水中の溶存ガス飽和度をパラメータとして求めることを特徴とする。   In the gas cavitation test method of the invention described in claim 1, a test pump for circulating the test water is installed in a closed circulation system in which the test water can be circulated, and dissolved gas in the test water is provided on the suction side of the test pump. An adjustment tank capable of adjusting the degree of saturation is installed, and a gas-liquid separator is installed between the adjustment tank and the test pump so that the status of the circulating test water can be visually observed and the degree of vacuum can be measured there. In addition, the dissolved gas saturation degree of the test water is adjusted by the adjustment tank, the test pump is operated, and the occurrence of gas cavitation in the circulating test water is confirmed by the gas-liquid separator, and the vacuum at that time is confirmed. By measuring the degree, the limit water pressure at which gas cavitation occurs is obtained using the dissolved gas saturation in the test water as a parameter.

請求項２記載の発明は、請求項１記載の発明のガスキャビテーション試験方法において、試験水中の溶存ガス飽和度を設定することに加えて、試験水の水温と試験ポンプの吸込流速を設定して試験水を循環させることにより、ガスキャビテーションが発生する限界の水圧を、溶存ガス飽和度のみならず水温および吸込流速をパラメータとして求めることを特徴とする。   The invention according to claim 2 is the gas cavitation test method according to claim 1, wherein, in addition to setting the dissolved gas saturation in the test water, the water temperature of the test water and the suction flow rate of the test pump are set. By circulating the test water, the limit water pressure at which gas cavitation occurs is obtained using not only the dissolved gas saturation but also the water temperature and suction flow velocity as parameters.

請求項３記載の発明のガスキャビテーション試験装置は、試験水が循環可能な閉鎖循環系に、試験水を循環させるための試験ポンプを設置するとともに、該試験ポンプの吸込側に試験水中の溶存ガス飽和度を調整可能な調整槽を設置し、該調整槽と試験ポンプとの間に、循環中の試験水の状況を目視観測可能かつそこでの真空度を計測可能な気液分離器を設置してなることを特徴とする。   The gas cavitation test apparatus according to claim 3 is provided with a test pump for circulating the test water in a closed circulation system through which the test water can be circulated, and a dissolved gas in the test water on the suction side of the test pump. An adjustment tank capable of adjusting the degree of saturation is installed, and a gas-liquid separator is installed between the adjustment tank and the test pump so that the state of the circulating test water can be visually observed and the degree of vacuum can be measured. It is characterized by.

請求項４記載の発明は、請求項３記載の発明のガスキャビテーション試験装置において、調整槽には循環水の水温を調整し維持するための水温調整手段を備え、かつ試験ポンプの吸込流速を計測するための流速計を具備してなることを特徴とする。   According to a fourth aspect of the present invention, in the gas cavitation test apparatus according to the third aspect of the present invention, the adjustment tank includes a water temperature adjusting means for adjusting and maintaining the water temperature of the circulating water, and measures the suction flow velocity of the test pump. It is characterized by comprising an anemometer for performing the above.

本発明のガスキャビテーション試験方法および試験装置によれば、調整槽により溶存ガス飽和度を様々に変更して試験水を循環させつつ、気液分離器を目視観測してガスキャビテーションの発生の有無やその状況を確認し、ガスキャビテーションが発生する限界の水圧を測定する試験を繰り返すことにより、ガスキャビテーションの発生やその状況と溶存ガス飽和度との関係を定量的に把握することができる。また、調整槽による試験水の水温を調節可能とし、試験ポンプの流速を計測することにより、溶存ガス飽和度のみならず水温や吸込流速の影響も同様に定量的に把握することができる。したがって本発明によれば、その試験結果を取水施設における吸水装置等の計画や設計や活用することにより、過度の安全率を見込むことなく合理的かつ経済的な計画・設計が可能となる。   According to the gas cavitation test method and the test apparatus of the present invention, the gas-liquid separator is visually observed and the presence or absence of gas cavitation is observed while circulating the test water with various changes in the dissolved gas saturation by the adjustment tank. By confirming the situation and repeating the test for measuring the limit water pressure at which gas cavitation occurs, it is possible to quantitatively grasp the occurrence of gas cavitation and the relationship between the situation and dissolved gas saturation. In addition, by making it possible to adjust the water temperature of the test water in the adjustment tank and measuring the flow rate of the test pump, it is possible to quantitatively grasp not only the dissolved gas saturation but also the influence of the water temperature and the suction flow rate. Therefore, according to the present invention, it is possible to plan and design rationally and economically without expecting an excessive safety factor by taking the test result and planning, designing or utilizing a water absorption device or the like in the water facility.

図１は本発明の一実施形態であるガスキャビテーション試験装置の概略構成を示す系統図である。
本実施形態の試験装置は、試験ポンプ１によって試験水を実線矢印のように循環させるための閉鎖循環系を基本構成としており、試験水の循環水量や水圧、流速等の試験条件を様々に変更して試験を繰り返すことによってガスキャビテーションの発生を再現し、その際の諸データを採取するために、試験ポンプ１の吐出圧を計測するための圧力計２、吸込圧を計測するための連成計３、吸込流速を計測するための流速計４をはじめとして、適宜のセンサ類が適所に設置されているものである。 FIG. 1 is a system diagram showing a schematic configuration of a gas cavitation test apparatus according to an embodiment of the present invention.
The test apparatus according to the present embodiment is based on a closed circulation system for circulating test water as indicated by solid arrows by the test pump 1, and variously changes test conditions such as the circulating water volume, water pressure, and flow rate of the test water. In order to reproduce the occurrence of gas cavitation by repeating the test and collect various data at that time, a pressure gauge 2 for measuring the discharge pressure of the test pump 1, a coupled for measuring the suction pressure Appropriate sensors are installed in place, including a total of 3 and an anemometer 4 for measuring the suction flow velocity.

特に本実施形態の試験装置は、ガスキャビテーションの発生に対する溶存ガス飽和度および水温の影響を把握することを主たる目的として構成されており、そのため上記の閉鎖循環系には試験水中の溶存ガス飽和度および水温を調整するための調整槽５と、試験ポンプ１の吸込側におけるガスキャビテーションの発生状況を目視観測するための気液分離器６とを設置しているものである。   In particular, the test apparatus of the present embodiment is configured mainly for the purpose of grasping the effects of dissolved gas saturation and water temperature on the occurrence of gas cavitation. Therefore, the above-mentioned closed circulation system has dissolved gas saturation in test water. And an adjustment tank 5 for adjusting the water temperature and a gas-liquid separator 6 for visually observing the occurrence of gas cavitation on the suction side of the test pump 1.

調整槽５は、試験水を貯留可能な小容量（たとえば０．１ｍ３程度）の水槽７中に、試験水に溶け込むガス（一般には大気で良い）を鎖線矢印で示すように調整弁８、エジェクタ９を介して吹き込みつつ、水槽７中の試験水を破線矢印で示すように調整用循環ポンプ１０により循環させ、かつ調整弁１１によりその循環水量を調節することによって溶存ガス飽和度を所望値に設定し維持するためのものである。なお、水槽７に設けられている符号１２は排水管、１３は給水管、１４はオーバーブロー管である。
また、この調整槽５においては試験水の水温も調整可能とされていて、水温調整手段としての加熱冷却コイル１５と熱源装置１６（たとえば冷温水ヒートポンプが好適に採用可能である）とが付設されている。 The adjustment tank 5 has an adjustment valve 8 as shown by a chain line arrow in a small volume (for example, about 0.1 m 3 ) of water tank 7 capable of storing the test water. While blowing through the ejector 9, the test water in the water tank 7 is circulated by the adjusting circulation pump 10 as indicated by the broken line arrow, and the amount of the circulating water is adjusted by the adjusting valve 11, thereby adjusting the dissolved gas saturation to a desired value. To set and maintain. In addition, the code | symbol 12 provided in the water tank 7 is a drain pipe, 13 is a water supply pipe, 14 is an overblow pipe.
Further, in the adjustment tank 5, the water temperature of the test water can also be adjusted, and a heating / cooling coil 15 and a heat source device 16 (for example, a cold / hot water heat pump can be suitably used) are provided as water temperature adjusting means. ing.

さらに、この調整槽５には、溶存ガス飽和度の設定と維持、および水温の設定と維持のための制御装置１７が付設されている。
制御装置１７は、主制御部１８、溶存ガス濃度取得部１９、水温取得部２０、状態設定部２１、指令部２２、およびメモリ２３を有しており、状態設定部２１により溶存ガス飽和度を所望値に設定し、水槽７に設置されている溶存ガスセンサ２４により溶存ガス濃度を検出し、それに基づき指令部２２が上記の調整弁８、１１をフィードバック制御してエアの吹き込み量と循環水量を調節することによって溶存ガス飽和度を設定値に維持するようにされている。なお、溶存ガス飽和度を低下させるように制御する場合には、気液分離器６（詳細後述）に付設されている真空ポンプ２８を作動させて気液分離器６内の圧力を下げ、それによって系内から脱気を行うと良い。
また、水温の設定および維持は、状態設定部２１により水温を所望値に設定し、水温センサ２５により水槽７内の水温を検出し、それにより指令部２２が熱源装置１６をフィードバック制御して水温を設定値に維持するようになっている。 Further, the adjusting tank 5 is provided with a control device 17 for setting and maintaining the dissolved gas saturation and setting and maintaining the water temperature.
The control device 17 includes a main control unit 18, a dissolved gas concentration acquisition unit 19, a water temperature acquisition unit 20, a state setting unit 21, a command unit 22, and a memory 23, and the state setting unit 21 determines dissolved gas saturation. The desired value is set, the dissolved gas concentration is detected by the dissolved gas sensor 24 installed in the water tank 7, and based on this, the command unit 22 feedback-controls the regulating valves 8 and 11 to control the amount of air blown and the amount of circulating water. By adjusting, dissolved gas saturation is maintained at a set value. In addition, when controlling so that dissolved gas saturation may be reduced, the vacuum pump 28 attached to the gas-liquid separator 6 (detailed later) is operated, and the pressure in the gas-liquid separator 6 is lowered, It is better to degas from inside the system.
The water temperature is set and maintained by setting the water temperature to a desired value using the state setting unit 21 and detecting the water temperature in the water tank 7 using the water temperature sensor 25, whereby the command unit 22 performs feedback control of the heat source device 16 to control the water temperature. Is maintained at the set value.

上記の調整槽５によって溶存ガス飽和度と水温が調整された試験水は、試験ポンプ１により吸い込まれてこの閉鎖循環系を循環するのであるが、調整槽５と試験ポンプ１との間には上記の気液分離器６が配置されていて、調整槽５からの試験水はこの気液分離器６を通ってから試験ポンプ１により吸い込まれるようになっている。符号２６はバイパス管である。
気液分離器６は内部を目視可能な透明な小容量（たとえば０．００４ｍ３程度）の縦型容器であって、試験水が試験ポンプ１に吸い込まれる直前にこの気液分離器６を通過することによって、そこでのガスキャビテーションの発生の有無やその状況（つまり、ガスキャビテーション現象の発生により溶存ガスが試験水中から気泡として発生する状況）を容易に目視観測することができ、かつ装置内の真空度を真空計２７により計測することにより、ガスキャビテーションが発生する時点の水圧を定量的に把握できるようになっている。また、気液分離器６には装置内を負圧とするための真空ポンプ２８も付設されている。 The test water whose dissolved gas saturation and water temperature are adjusted by the adjustment tank 5 is sucked by the test pump 1 and circulates in this closed circulation system. The gas-liquid separator 6 is arranged, and the test water from the adjustment tank 5 passes through the gas-liquid separator 6 and is then sucked in by the test pump 1. Reference numeral 26 denotes a bypass pipe.
The gas-liquid separator 6 is a transparent small container (for example, about 0.004 m 3 ) that can be visually observed inside, and passes through the gas-liquid separator 6 immediately before the test water is sucked into the test pump 1. By doing so, the presence or absence of gas cavitation there and its situation (that is, the situation where dissolved gas is generated as bubbles from the test water due to the occurrence of gas cavitation phenomenon) can be easily visually observed, and By measuring the degree of vacuum with the vacuum gauge 27, the water pressure at the time when gas cavitation occurs can be quantitatively grasped. The gas-liquid separator 6 is also provided with a vacuum pump 28 for making the inside of the apparatus have a negative pressure.

上記構成の試験装置による試験は、試験ポンプ１を運転して試験水を循環させた際のガスキャビテーションの発生の有無やその状況を気液分離器６で確認することで行い、その際には試験水の循環水量や吐出圧、吸込圧、吸込流速等を様々に変更して試験を繰り返すことにより、ガスキャビテーションの発生因子に関するデータを採取することを基本とするのであるが、本実施形態の試験装置では特に従来においては考慮されていなかった溶存ガス飽和度および水温の影響を把握することが可能である。
すなわち、上記装置では試験水中の溶存ガス飽和度および試験水の水温を任意に調整可能な調整槽５を備えたことにより、その調整槽５によって溶存ガス飽和度と水温を様々に変更して試験を繰り返すことによりガスキャビテーションに対する溶存ガス飽和度および水温の影響を把握することができ、ガスキャビテーションが発生する限界の水圧を溶存ガス飽和度および水温をパラメータとして定量的に求めることができる。 The test by the test apparatus having the above-described configuration is performed by confirming the presence or state of gas cavitation when the test pump 1 is operated and the test water is circulated and the state thereof by the gas-liquid separator 6. It is based on collecting data on gas cavitation generation factors by repeating the test with various changes in test water circulating water volume, discharge pressure, suction pressure, suction flow velocity, etc. In the test apparatus, it is possible to grasp the influence of the dissolved gas saturation and the water temperature, which were not considered in the past.
That is, in the above apparatus, by providing the adjustment tank 5 in which the dissolved gas saturation in the test water and the water temperature of the test water can be arbitrarily adjusted, the dissolved gas saturation and the water temperature are variously changed by the adjustment tank 5 for the test. By repeating the above, the influence of dissolved gas saturation and water temperature on gas cavitation can be grasped, and the limit water pressure at which gas cavitation occurs can be obtained quantitatively using dissolved gas saturation and water temperature as parameters.

図２は上記試験装置による試験により得た結果の一例を示す。これは、ガスキャビテーションが発生した時点の水圧と水温との関係を溶存ガス飽和度（１００％と８０％の２段階）および吸込流速（１．０ｍ／ｓと０．５ｍ／ｓの２段階）をパラメータとして求めたものである。図中１ａ〜４ａはガスキャビテーションが発生するものの連続運転はそのまま可能である限界、１ｂ〜４ｂはガスキャビテーションが発生すると連続運転が不可能（１０分程度の短時間のうちには停止してしまう）となる場合を示す。
この図から、他の条件が同じであれば、水温が低いほど、溶存ガス飽和度が低いほど、吸込流速が小さいほど、ガスキャビテーションが生じ難く、したがって安定な運転を継続し易い傾向にあることが分かり、ガスキャビテーションの発生条件や運転限界としての水温や溶存ガス飽和度、流速の値をこの図から定量的に決定することができる。 FIG. 2 shows an example of the results obtained by the test using the test apparatus. This is based on the relationship between the water pressure and water temperature at the time when gas cavitation occurs, and the dissolved gas saturation (100% and 80% in two stages) and the suction flow rate (1.0 m / s and 0.5 m / s in two stages). Is obtained as a parameter. In the figure, 1a to 4a indicate that gas cavitation occurs but continuous operation is possible, and 1b to 4b indicate that continuous operation is impossible when gas cavitation occurs (the operation will stop within a short period of about 10 minutes). ).
From this figure, if the other conditions are the same, the lower the water temperature, the lower the dissolved gas saturation, and the lower the suction flow velocity, the less likely gas cavitation will occur, and therefore there is a tendency to continue stable operation. From this figure, it is possible to quantitatively determine the values of water cavities, dissolved gas saturation, and flow velocity as gas cavitation generation conditions and operation limits.

なお、上記実施形態では溶存ガス飽和度の他に水温と吸込流速もパラメータとしたが、それらの影響を特に考慮する必要がなければ溶存ガス飽和度のみをパラメータとすることでも充分に有効であり、その場合には調整槽５や制御装置１７には水温調整のための手段や機構は省略して良いし、流速計４の設置やその計測も不要であれば省略して差し支えない。   In the above embodiment, the water temperature and the suction flow velocity are also used as parameters in addition to the dissolved gas saturation. However, it is sufficiently effective to use only the dissolved gas saturation as a parameter unless it is particularly necessary to consider their influence. In that case, means and mechanisms for adjusting the water temperature may be omitted in the adjustment tank 5 and the control device 17, and the installation and measurement of the anemometer 4 may be omitted if unnecessary.

本発明の実施形態である試験装置の概略構成を示す系統図である。1 is a system diagram showing a schematic configuration of a test apparatus according to an embodiment of the present invention. 本発明の試験方法により得られた結果の一例を示す図である。It is a figure which shows an example of the result obtained by the test method of this invention.

符号の説明Explanation of symbols

１ 試験ポンプ
２ 圧力計
３ 連成計
４ 流速計
５ 調整槽
６ 気液分離器
７ 水槽
８ 調整弁
９ エジェクタ
１０ 調整用循環ポンプ
１１ 調整弁
１５ 加熱冷却コイル
１６ 熱源装置
１７ 制御装置
１８ 主制御部
１９ 溶存ガス濃度取得部
２０ 水温取得部
２１ 状態設定部
２２ 指令部
２３ メモリ
２４ 溶存ガスセンサ
２５ 水温センサ
２７ 真空計
２８ 真空ポンプ DESCRIPTION OF SYMBOLS 1 Test pump 2 Pressure gauge 3 Compound meter 4 Current meter 5 Adjustment tank 6 Gas-liquid separator 7 Water tank 8 Adjustment valve 9 Ejector 10 Adjustment circulation pump 11 Adjustment valve 15 Heating / cooling coil 16 Heat source device 17 Control device 18 Main control part DESCRIPTION OF SYMBOLS 19 Dissolved gas concentration acquisition part 20 Water temperature acquisition part 21 State setting part 22 Command part 23 Memory 24 Dissolved gas sensor 25 Water temperature sensor 27 Vacuum gauge 28 Vacuum pump

Claims (4)

試験水が循環可能な閉鎖循環系に、試験水を循環させるための試験ポンプを設置するとともに、該試験ポンプの吸込側に試験水中の溶存ガス飽和度を調整可能な調整槽を設置し、該調整槽と試験ポンプとの間には、循環中の試験水の状況を目視観測可能かつそこでの真空度を計測可能な気液分離器を設置しておき、
前記調整槽により試験水の溶存ガス飽和度を調整して試験ポンプを運転し、循環中の試験水におけるガスキャビテーションの発生状況を前記気液分離器により確認してその時点の真空度を計測することによって、ガスキャビテーションが発生する限界の水圧を溶存ガス飽和度をパラメータとして求めることを特徴とするガスキャビテーション試験方法。 A test pump for circulating the test water is installed in a closed circulation system through which the test water can circulate, and an adjustment tank capable of adjusting the dissolved gas saturation in the test water is installed on the suction side of the test pump. Between the adjustment tank and the test pump, a gas-liquid separator capable of visually observing the status of the circulating test water and measuring the degree of vacuum there is installed.
Adjust the dissolved gas saturation of the test water with the adjustment tank, operate the test pump, check the occurrence of gas cavitation in the circulating test water with the gas-liquid separator, and measure the degree of vacuum at that time A gas cavitation test method characterized in that a water pressure at a limit at which gas cavitation occurs is obtained using dissolved gas saturation as a parameter. 請求項１記載のガスキャビテーション試験方法であって、
試験水中の溶存ガス飽和度を設定することに加えて、試験水の水温と試験ポンプの吸込流速を設定して試験水を循環させることにより、ガスキャビテーションが発生する限界の水圧を、溶存ガス飽和度のみならず水温および吸込流速をパラメータとして求めることを特徴とするガスキャビテーション試験方法。 A gas cavitation test method according to claim 1,
In addition to setting the dissolved gas saturation in the test water, set the test water temperature and the test pump suction flow rate to circulate the test water, thereby reducing the water pressure at the limit where gas cavitation occurs to the dissolved gas saturation. A gas cavitation test method characterized by determining water temperature and suction flow velocity as parameters as well as the temperature. 試験水が循環可能な閉鎖循環系に、試験水を循環させるための試験ポンプを設置するとともに、該試験ポンプの吸込側に試験水中の溶存ガス飽和度を調整可能な調整槽を設置し、該調整槽と試験ポンプとの間に、循環中の試験水の状況を目視観測可能かつそこでの真空度を計測可能な気液分離器を設置してなることを特徴とするガスキャビテーション試験装置。   A test pump for circulating the test water is installed in a closed circulation system through which the test water can circulate, and an adjustment tank capable of adjusting the dissolved gas saturation in the test water is installed on the suction side of the test pump. A gas cavitation test apparatus characterized in that a gas-liquid separator capable of visually observing the status of circulating test water and measuring the degree of vacuum therein is installed between the adjustment tank and the test pump. 請求項３記載のガスキャビテーション試験装置であって、
調整槽には循環水の水温を調整し維持するための水温調整手段を備え、かつ試験ポンプの吸込流速を計測するための流速計を具備してなることを特徴とするガスキャビテーション試験装置。


A gas cavitation test apparatus according to claim 3,
A gas cavitation test apparatus characterized in that the adjustment tank is provided with a water temperature adjusting means for adjusting and maintaining the water temperature of the circulating water, and further comprising a flowmeter for measuring the suction flow velocity of the test pump.


JP2006165771A 2006-06-15 2006-06-15 Gas cavitation test method and apparatus Expired - Fee Related JP4793645B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2006165771A JP4793645B2 (en) 2006-06-15 2006-06-15 Gas cavitation test method and apparatus

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2006165771A JP4793645B2 (en) 2006-06-15 2006-06-15 Gas cavitation test method and apparatus

Publications (2)

Publication Number Publication Date
JP2007333566A true JP2007333566A (en) 2007-12-27
JP4793645B2 JP4793645B2 (en) 2011-10-12

Family

ID=38933177

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2006165771A Expired - Fee Related JP4793645B2 (en) 2006-06-15 2006-06-15 Gas cavitation test method and apparatus

Country Status (1)

Country Link
JP (1) JP4793645B2 (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107884427A (en) * 2017-11-09 2018-04-06 北京理工大学 Gas content measuring system in a kind of bubbling crystallzation bubble based on circulating water tunnel
CN108169062A (en) * 2017-12-26 2018-06-15 中国石油大学(华东) Simulate the visual test device and method of subterranean coal gas preservation desorption process
CN112683520A (en) * 2020-12-08 2021-04-20 宁波市产品食品质量检验研究院(宁波市纤维检验所) Hydraulic valve cavitation erosion test device under multiphase flow condition and test method thereof
CN114923667A (en) * 2021-06-16 2022-08-19 中国科学院力学研究所 Circulating water tank experimental device and method for realizing controllable solution saturation

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS4895889A (en) * 1972-03-01 1973-12-08
JPS5737244A (en) * 1980-08-18 1982-03-01 Fuji Electric Co Ltd Device for measuring amount of gas dissolved in liquid
JPH04232437A (en) * 1990-06-18 1992-08-20 Westinghouse Electric Corp <We> On-line measuring apparatus for measuring effective partial pressure of dissolved gas in liquid
JP3579822B2 (en) * 1999-07-19 2004-10-20 清水建設株式会社 Water absorption device
WO2006034040A2 (en) * 2004-09-17 2006-03-30 Product Systems Incorporated Method and apparatus for cavitation threshold characterization and control

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS4895889A (en) * 1972-03-01 1973-12-08
JPS5737244A (en) * 1980-08-18 1982-03-01 Fuji Electric Co Ltd Device for measuring amount of gas dissolved in liquid
JPH04232437A (en) * 1990-06-18 1992-08-20 Westinghouse Electric Corp <We> On-line measuring apparatus for measuring effective partial pressure of dissolved gas in liquid
JP3579822B2 (en) * 1999-07-19 2004-10-20 清水建設株式会社 Water absorption device
WO2006034040A2 (en) * 2004-09-17 2006-03-30 Product Systems Incorporated Method and apparatus for cavitation threshold characterization and control
JP2008514125A (en) * 2004-09-17 2008-05-01 プロダクト・システムズ・インコーポレイテッド Method and apparatus for characterization and control of cavitation threshold

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107884427A (en) * 2017-11-09 2018-04-06 北京理工大学 Gas content measuring system in a kind of bubbling crystallzation bubble based on circulating water tunnel
CN108169062A (en) * 2017-12-26 2018-06-15 中国石油大学(华东) Simulate the visual test device and method of subterranean coal gas preservation desorption process
CN112683520A (en) * 2020-12-08 2021-04-20 宁波市产品食品质量检验研究院(宁波市纤维检验所) Hydraulic valve cavitation erosion test device under multiphase flow condition and test method thereof
CN114923667A (en) * 2021-06-16 2022-08-19 中国科学院力学研究所 Circulating water tank experimental device and method for realizing controllable solution saturation
CN114923667B (en) * 2021-06-16 2024-01-26 中国科学院力学研究所 Experimental device and method for realizing controllable solution saturation of circulating water tank

Also Published As

Publication number Publication date
JP4793645B2 (en) 2011-10-12

Similar Documents

Publication Publication Date Title
JP4793645B2 (en) Gas cavitation test method and apparatus
JP2016525682A5 (en)
US9651486B2 (en) Method and device for measuring the gas content in a liquid, and use of such a device
EP2568169A1 (en) Wind turbine with tower climatisation system using outside air
KR20130036711A (en) Method for cooling a heat-producing device and a cooling device for a heat-producing device
EP3036025B1 (en) Method and device for degassing
JP6192796B1 (en) Leak detection device
JP2010139207A (en) Steam generation amount calculating method for boiler
SE513882C2 (en) Method and apparatus for detecting leakage from a chemical soda boiler system
Bidhandi et al. The influence of SiO2 nanoparticles on cavitation initiation and intensity in a centrifugal water pump
US10384957B2 (en) Apparatus and method for detecting degassed cation conductivity
JP6235687B1 (en) Leak detection device
JP4231024B2 (en) Absorption diagnosis method and apparatus for absorption refrigerator
KR101393136B1 (en) Testing system for deaerater and method thereof
JP5384401B2 (en) Boiler water level control method
JP5772765B2 (en) Water supply pump and method for detecting full water in water supply pump
JP2009024935A (en) Flow rate control system of circulating pump and flow rate control method of circulating pump
CN210153562U (en) Quick detection device that heat supply network heat exchange tube and tube sheet leaked
RU168476U1 (en) Device for monitoring and controlling the quality of steam in surface-type evaporators
BE1023923B1 (en) METHOD AND DETECTOR FOR DETECTING AIR BUBBLES OR AIR CONCLUSIONS IN A SYSTEM, AS WELL AS AN INSTALLATION CONTAINING SUCH DETECTOR
KR101057418B1 (en) Dyeing coolant recycling unit
JP2007192686A (en) Precision inspecting method of dew point meter and fuel cell evaluation device
JP2007101537A (en) Improved online steam flow velocity measurement device and method
RU182097U1 (en) Device for monitoring and controlling the quality of steam in surface-type evaporators
CN210534112U (en) Scale inhibitor testing arrangement

Legal Events

Date Code Title Description
A621 Written request for application examination

Free format text: JAPANESE INTERMEDIATE CODE: A621

Effective date: 20081119

A977 Report on retrieval

Free format text: JAPANESE INTERMEDIATE CODE: A971007

Effective date: 20110303

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20110329

A521 Request for written amendment filed

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20110519

TRDD Decision of grant or rejection written
A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

Effective date: 20110614

A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

A61 First payment of annual fees (during grant procedure)

Free format text: JAPANESE INTERMEDIATE CODE: A61

Effective date: 20110713

R150 Certificate of patent or registration of utility model

Free format text: JAPANESE INTERMEDIATE CODE: R150

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20140805

Year of fee payment: 3

LAPS Cancellation because of no payment of annual fees