JPH11304664A - Factory test method for pump apparatus for liquefied gas - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a factory test method in which the cost of a factory test can be reduced by a method wherein, regarding only one representative pump, a pump performance test is made by a substitute low-temperature liquid and only a rotation confirmation test in a gas is made to other pumps so as to omit their pump performance test. SOLUTION: As a method for the rotation confirmation test in a gas of a pump for a liquefied gas, a pipe 20 which is used to supply a high-pressure gas at a proper pressure from the outside is connected to the entrance part 12' or the like of a liquid- supply flow passage 12 or the like at a static-pressure bearing 5E or the like. The high-pressure gas to be supplied is passed through the pipe 20, it is then passed through the liquid-supply flow passage 12, and it is spouted from the static-pressure bearing 5E so as to support a pump shaft 5A. In this manner, the high-pressure gas at the proper pressure is supplied to the static-pressure bearing 5F from the pipe 20. Therefore, since the pump shaft 5A is turned in a noncontact state with the static-pressure bearing 5E or the like, the sliding abrasion of the static-pressure bearing 5E or the like is not generated. Irrespective of a material for the static-pressure bearing 5E or the like, the rotation confirmation test of the pump, for the liquefied gas, comprising the static-pressure bearing 5E can be made safely.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of testing a liquefied gas pump device at a factory and a reduction in the cost of the factory test.

[0002]

2. Description of the Related Art A liquefied gas pump device for transporting a liquefied gas such as liquefied natural gas (hereinafter referred to as a liquefied gas pump) conventionally employs a hydrostatic bearing in order to extend the bearing life. Is known to be.

Here, such a liquefied gas pump will be described with reference to FIG. 4, taking a liquefied gas tank pump device as an example.

[0004] Reference numeral 1 denotes a liquefied gas tank, reference numeral 1 a denotes a ceiling plate of the gas tank 1, and reference numeral 2 denotes a liquid supply pipe suspended in the liquefied gas tank 1. This liquefied gas tank 1
A suction valve 3 is attached to a lower end of the pumping pipe 2 suspended in the inside, and a pump body 5 for the liquefied gas tank is installed on a seating surface 4 of the pumping pipe 2. , A plurality of discharge ports provided on the outer periphery of the pump body 5. A head plate 7 provided with a pump lifting mechanism is provided at the top of the liquid pumping pipe 2. Reference numeral 8 denotes a lifting wire, reference numeral 9 denotes a power supply cable, and reference numeral 10 denotes a hoist.

[0005] The liquefied gas tank pump main body 5 is provided, for example, by means of the lifting wire 8 from the head plate 7 inside the pumping pipe 2 vertically suspended from the ceiling plate 1 a of the liquefied gas tank 1. Depth 50
m and is seated on the seating surface 4 below the pumping pipe 2 and installed.

The liquefied gas tank pump body 5
Is supplied with power by a power supply cable 9,
When the operation of the pump is started, the liquefied gas is sucked in from the suction valve 3, pressurized and discharged from the discharge port 6, and rises in the liquid pumping pipe 2 as shown by an arrow in the drawing to be discharged. 1
Sent to 1.

In such a liquefied gas pump device, for example, as described in JP-A-8-296586, a motor is housed in a casing of a vertical shaft pump, and the shaft and impeller of the pump are rotated. A rotating shaft on which a balance disk, which is an axial thrust balancer, is fixed above the impeller;
It is already known that upper, middle and lower bearings have a hydrostatic bearing having a long bearing life and excellent vibration damping properties. The middle and upper bearings are further provided with auxiliary ball bearings.

A configuration example of a conventional liquefied gas pump body will be described with reference to a drawing of a liquefied gas tank pump body shown in FIG.

The structure of the liquefied gas tank pump body 5 is as follows.
An inducer 5B, a plurality of impellers 5C, and a submerged motor rotor 5D attached to the pump rotating shaft 5A for improving the suction performance are fixed, and they have an integral structure and rotate integrally. ing. The pump rotating shaft 5A, the inducer 5B, the plurality of impellers 5C, and the submerged motor rotor 5D are radially supported by self-liquid lubricated static pressure bearings 5E, 5F, 5G. On the other hand, in the axial direction, the axial thrust is self-balanced by a thrust balancing device including a balance disk 5J fixed to the pump rotating shaft 5A, floats in the liquid of the pump rotating body, and the auxiliary ball bearings 5H, 5I The thrust force does not act at all.

Next, a conventional factory test method for such a liquefied gas pump will be described.

Conventionally, in a factory test of a liquefied gas pump, since a liquefied gas is flammable, in many cases, a factory test is performed using an alternative low-temperature liquid such as liquefied nitrogen in consideration of safety. I have. In the case of a factory test using liquefied nitrogen or the like, the following steps are required for testing a single pump. Here, an example of a factory test will be described for the case of a liquefied gas tank pump as an example.

First, FIG. 3 shows a schematic diagram of a test facility for a liquefied gas pump. The test equipment includes a storage tank 15, a suction pipe 16, a test pot 17, and a discharge pipe 18, which form a closed loop (hereinafter referred to as a test loop). The liquefied gas tank pump 5 for performing the factory test is mounted on a test simulated pumping pipe 19 attached to the test pot 17.

By the way, if water vapor contained in the air in the test loop remains before the liquefied nitrogen is injected into the test loop including the liquefied gas pump 5, the liquefied nitrogen is injected into the test loop. In the low-temperature state after the cooling, the water vapor freezes, which causes a trouble during a liquefied gas pump operation test. In order to prevent this, as the next step, nitrogen gas heated by a heater etc. was sent into the test loop,
Extrude steam together with air, fill the test loop with heated nitrogen gas and dry. This step is hereinafter referred to as drying.

When the test loop drying is completed,
In order to inject liquefied nitrogen into the test loop, first, nitrogen gas is sent into the test loop without heating, and the inside of the test loop including the liquefied gas pump is -196 which is the boiling point of nitrogen.
Cool down to ° C. This step is hereinafter referred to as cool down.

When the inside of the test loop including the liquefied gas pump is cooled to -196 ° C., which is the boiling point of nitrogen, by the cool down of the test loop, liquefied nitrogen gradually starts flowing into the test loop. This step is hereinafter referred to as a liquid container. After the required amount of liquefied nitrogen has been injected into the test loop,
Perform a pump operation test.

After the operation test of the pump is completed, liquefied nitrogen is withdrawn from the test loop. This step is hereinafter referred to as drainage.

After completion of draining, it is difficult to disassemble and inspect the cooled liquefied gas pump as it is, so nitrogen gas heated by a heater or the like is fed into the test loop, and the test loop including the liquefied gas pump is cooled to a low temperature. Warm to room temperature. This step is hereinafter referred to as hot-up. After hot-up is completed and the liquefied gas pump is warmed to room temperature,
Withdraw the liquefied gas pump 5 from the test pot 17,
Perform overhaul.

The above is one of a series of steps in a factory test of one liquefied gas pump.

If a plurality of liquefied gas pumps having the same specifications are produced, a plurality of pumps for the liquefied gas of the same specification are conventionally performed one by one, and a long-term factory test is performed. Was.

[0020]

As described above, in a factory test of a liquefied gas pump, there are various steps, and each of them takes a long time. In preparation for the test, several hours for drying, several hours for cool down,
It takes several hours to fill the tank and then several hours to perform a factory test of the liquefied gas pump. Also, after the test, it takes several hours each for draining and hot-up, so that a test of one liquefied gas pump requires several days to several weeks from preparation to overhaul after factory test. Therefore, when there are a plurality of liquefied gas pumps having the same specifications, a factory test is performed for a very long time to repeat this process.

If the period of the factory test is long, the following problems occur. The liquefied nitrogen used in the factory test has a low boiling point of -196 ° C., so that the amount of evaporation is very large, so that the amount of liquefied nitrogen used becomes large. In addition, the labor cost is naturally large, and the period until shipment of the liquefied gas pump becomes long.

As described above, in a factory test in which a plurality of liquefied gas pumps having the same specifications are produced, conventionally, it takes a long time from test preparation to disassembly and inspection of the liquefied gas pump after the test. However, there is a problem that the factory test is performed for a very long time and the cost becomes extremely high.

An object of the present invention is to solve the above problems and to provide a factory test method of a liquefied gas pump device for reducing the cost of a liquefied gas pump factory test.

[0024]

When a plurality of liquefied gas pumps having the same specifications are produced, a slight difference in the hydraulic performance of each liquefied gas pump usually occurs. This is largely due to slight dimensional differences in individual liquefied gas pump components. However, if the dimensional accuracy of parts such as impellers and diffusers that greatly affect the hydraulic performance of the pump is strictly controlled, the difference in hydraulic performance between the individual liquefied gas pumps can be reduced.
By accumulating the data of the hydraulic performance of such a liquefied gas pump, the range of the hydraulic performance difference of the pump can be grasped.

The present invention focuses on such points, and
In a factory test where there are multiple liquefied gas pumps with the same specifications, we conducted a factory test in which all liquefied gas pumps with the same specifications were subjected to a pump performance test using an alternative low-temperature liquid such as liquefied gas or liquefied nitrogen. , Only one representative is subjected to a pump performance test with an alternative low-temperature liquid such as liquefied gas or liquefied nitrogen, and the remaining liquefied gas pump is only subjected to a pump rotation test in a gas such as air or gas. By doing so, the conventional problem is solved, and the cost of the liquefied gas pump in the factory test is reduced.

[0026]

BEST MODE FOR CARRYING OUT THE INVENTION The test for confirming the rotation of a liquefied gas pump in a gas, which is a feature of the present invention, is not limited to a liquefied gas pump having a hydrostatic bearing, but a liquefied gas pump device of any structure. Install the liquefied gas pump in some kind of rotation confirmation test equipment, connect the power supply to the liquefied gas pump motor, rotate the motor, and check that the liquefied gas pump rotor rotates normally. Performed for the purpose of confirmation.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows an embodiment of the present invention in which the method for confirming the rotation of a pump, which is the factory test method of the present invention, is applied to the factory test apparatus for a liquefied gas tank pump apparatus described with reference to FIG. FIG.

FIG. 1 shows a case of a rotation confirmation test of the liquefied gas pump 5 having the hydrostatic bearing described with reference to FIG. 5, and the liquefied gas pump 5 is mounted on a test pot 17. It is installed in a simulated liquid pumping pipe 19. In order to conduct a rotation confirmation test in a gas, equipment dedicated to the rotation test may be manufactured and used. Alternatively, as shown in FIG. 1, a pot 17 for a liquid test and a simulated pumping tube 19 for a liquid test may be used. If used, the cost of fabricating a new test facility dedicated to rotational testing can be saved. In this way, in the rotation confirmation test in gas, the liquefied gas pump is installed in some test equipment, the power supply is connected to the liquefied gas pump motor, the motor is rotated, and the liquefied gas pump rotor is normal. Confirm that it rotates.

As shown in FIG. 5, a liquefied gas pump having a hydrostatic bearing is generally provided with an upper hydrostatic bearing 5E,
Although there are three hydrostatic bearings at the middle hydrostatic bearing 5F and the lower hydrostatic bearing 5G, when the pump is operated in a liquefied gas, these hydrostatic bearings 5E, 5F and 5G are provided with an impeller 5C. The high-pressure pump discharge liquid pressurized by the liquid supply passages 12, 13,
The pump shaft 5A is supplied to the hydrostatic bearings 5E, 5F, 5G through the pump shaft 14 and the high-pressure liquid causes the pump shaft 5A to rotate.
The structure is supported in a non-contact state with 5F and 5G.

In a liquefied gas pump having such a hydrostatic bearing, when a rotation confirmation test in a gas is performed,
There are the following two methods.

First, the first method is to use the hydrostatic bearings 5E, 5F,
This is a case where a rotation confirmation test is simply performed in a gas without supplying a high-pressure gas to 5G. In this case, since the hydrostatic bearing portion is not supported by the high-pressure gas, the rotating pump shaft 5A swings over the gap between the hydrostatic bearing and the pump shaft, so that the sliding of the hydrostatic bearings 5E, 5F, 5G is performed. The moving part may come into contact with the pump shaft 5A and be worn. However, the hydrostatic bearing 5
If a carbon-based sliding material having good slidability or a Teflon material is used for the material of E, 5F, 5G, the hydrostatic bearings 5E, 5G can be used.
Even if the F and 5G slide on the pump shaft 5A, the calorific value is small, so that the test can be performed without any problem during a short rotation confirmation test.

The auxiliary ball bearing 5 of the liquefied gas pump
H and 5I are lubricated by the liquefied gas in the liquefied gas, but since there is no liquid serving as a lubricant during the rotation confirmation test in the gas, the rolling element (ball) inside the ball bearing and the rolling element are mutually separated. There is a danger that the retainer (retainer), which has the function of retaining the members at equal intervals so that they do not touch each other, may slide and wear. However, also in this case, the material of the retainer (retainer) of the auxiliary ball bearings 5H and 5I is a carbon-based sliding material having good slidability.
Alternatively, if the Teflon material is used, even if the rolling element (ball) and the retainer (retainer) slide, the calorific value is small, so that the test can be performed without any problem during a short rotation confirmation test.

Next, as a second method, at the time of a rotation confirmation test in a gas, the hydrostatic bearing 5 is subjected to some method.
E, 5F, 5G are supplied with a high-pressure gas of an appropriate pressure, and when the pump shaft 5A rotates, the hydrostatic bearings 5E, 5F, 5G
There is a way to avoid contact. The method will be described below.

In the present invention, as shown in FIG. 1, as a method of confirming the rotation of a liquefied gas pump having a static pressure bearing in a gas, a liquid supply passage 12 of the static pressure bearings 5E, 5F and 5G is used. , 13, 14 at the entrances 12 ', 13', 14 '
Piping 2 for supplying high pressure gas of appropriate pressure from outside
0 is connected. FIG. 2 shows an enlarged view of the vicinity of the upper hydrostatic bearing 5E. As shown in FIG. 2, the high-pressure gas to be supplied passes through the pipe 20, then passes through the liquid supply flow path 12, and is blown out from the upper hydrostatic bearing 5E to support the pump shaft 5A. .

As described above, the pump shaft 5A rotates in a non-contact state with the hydrostatic bearings 5E, 5F and 5G by supplying the high-pressure gas of an appropriate pressure from the pipe 20 to the hydrostatic bearing. The sliding wear of the hydrostatic bearings 5E, 5F, and 5G does not occur, and the rotation confirmation test can be safely performed on the liquefied gas pump having the hydrostatic bearing regardless of the material of the hydrostatic bearings 5E, 5F, and 5G. it can. However, in the case of the auxiliary ball bearings 5H and 5I as well, since there is no liquid serving as a lubricant, the rolling elements (balls) and the retainer (retainer) inside the ball bearings may slide and wear. As the material of the retainers (retainers) of the auxiliary ball bearings 5H and 5I, a carbon-based sliding material having good slidability or a Teflon material may be used.
Thereby, even if the rolling element and the cage slide, the calorific value is small, so that the test can be performed without any problem during the short-time rotation confirmation test.

The gas supplied to the hydrostatic bearings 5E, 5F, 5G may be air or a gas such as nitrogen. Further, the gas to be supplied must be a gas having a pressure appropriately high with respect to the atmospheric pressure of the bearing portion in order to support the pump shaft.

The pipe 20 for supplying the high-pressure gas may be made of metal or a hose made of vinyl or the like as long as it can withstand the pressure used. In addition, the liquid supply channel inlets 12 ', 13', and 14 'of the liquefied gas pump need to have some kind of joint structure such as a female screw or a flange so that the pipe 20 can be connected.

Although the present invention has been described in detail with reference to a liquefied gas tank pump device as an example, the present invention relates to a case of another type of liquefied gas pump device (for example, Japanese Patent Publication No. 7-655).
As a matter of course, the present invention can also be applied to a pot-type liquefied gas pump in which a pump is housed in a suction casing as disclosed in JP-A-88. In addition, the present invention is effective not only for a liquefied gas but also for a pump handling a low-temperature liquid.

According to the method of the present invention as described above, a rotation confirmation test of the liquefied gas pump can be performed, and the cost of the factory test of the liquefied gas pump can be reduced.

[0041]

According to the present invention, in a factory test in the case where there are conventionally a plurality of liquefied gas pumps having the same specification, all of the liquefied gas pumps having the same specification are replaced with a cryogenic gas such as liquefied gas or liquefied nitrogen. The factory test which had been conducting the pump performance test by liquefied gas
Alternatively, a pump performance test is performed using an alternative low-temperature liquid such as liquefied nitrogen, and for the remaining liquefied gas pumps, only a rotation confirmation test in gas is performed, and the performance test of the liquefied gas pump is omitted. Significant cost reduction of pump factory test can be achieved.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a liquefied gas pump factory test apparatus showing an embodiment of the present invention.

FIG. 2 is an enlarged view of the vicinity of an upper hydrostatic bearing of a liquefied gas pump according to an embodiment of the present invention.

FIG. 3 is a schematic view of a conventional liquefied gas pump factory test apparatus.

FIG. 4 is an overall view of a liquefied gas tank pump device.

FIG. 5 is a structural view of a liquefied gas tank pump device main body.

[Explanation of Signs] 1 ... liquefied gas tank, 1a ... ceiling plate, 2 ... pumping pipe, 3 ...
Suction valve, 4 ... Seat surface, 5 ... Liquid gas pump body, 5A ...
Rotary shaft, 5B ... Inducer, 5C ... Impler, 5D ... Submerged motor rotor, 5E, 5F, 5G ... Static pressure bearing, 5H, 5I ... Auxiliary ball bearing, 5J ... Balance disk, 5K ... Pump cover, 5L ... Top Bearing housing, 5
M: Medium bearing housing, 6: Discharge port, 7: Head plate, 8: Lifting wire, 9: Power supply cable, 10: Winding machine, 11: Discharge pipe, 12: Upper static pressure bearing liquid supply flow path, 1
2 ': Upper static pressure bearing fluid supply channel inlet, 13 ... Medium static pressure bearing fluid feed channel, 13' ... Medium hydrostatic bearing fluid feed channel inlet, 14 ... Lower static pressure bearing fluid feed channel, 14 ': lower hydrostatic bearing liquid supply channel inlet, 15 ... liquefied nitrogen storage tank, 16 ... suction pipe, 17
… Test pot, 18… discharge pipe, 19… simulated pumping pipe for test, 20… high pressure gas supply pipe.

Claims (1)

[Claims] 1. A pump shaft, a drive unit for rotating and driving the pump shaft, an impeller provided at a position below the drive unit along the pump shaft to pressurize liquefied gas sucked from a liquefied gas tank, and an impeller. In a factory test of a liquefied gas pump device that sucks and discharges a liquefied gas constituted by a discharge hole that discharges liquefied gas pressurized by a vehicle and a plurality of bearings that support a pump shaft, rotation of the liquefied gas pump device is performed. A factory test method for a liquefied gas pump device, wherein the confirmation test is performed in a gas such as air or gas.