JPS6363757B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The invention comprises a circulation pump operative to generate pressure and a turbine mounted on the same shaft as said circulation pump for recovering the energy contained in the liquid flowing back. In particular, it relates to circulation pump/turbine composite units used in seawater desalination plants.

In seawater desalination plants that operate according to the principle of reversible osmosis, circulation pumps are usually used to increase the pressure, and the pressure difference of the circulation pumps is only partially resolved by modules. . Therefore, it is often the case that the remaining pressure difference is reduced by means of a throttle valve, and the residual pressure is used to pump the liquid back into the sea.

Combined units are also already known which are designed to perform the pressure reduction by means of a turbine mounted on the same shaft as the circulation pump. Up to now, in known combination units, a pump with counter-rotating rotation has been used as a turbine (see European Published Patent Application No.
(See No. 8260). The advantage of this composite unit is that the pressure difference to be eliminated can be set low and there is no need to prepare a separate supply device. However, the disadvantage is that the efficiency of the turbine is very low, and increasing the efficiency of the turbine is very important in this type of plant.

It is therefore an object of the invention to significantly increase the efficiency of a circulating pump-turbine combination unit of the type mentioned at the outset. Thus, the above object, according to the invention, uses a Pelton turbine and a circulation pump which serves to transport the liquid back to its reservoir source (e.g. the sea), and which uses a circulation pump which serves to generate pressure. This was accomplished by attaching the Pelton turbine and the circulation pump for pumping back the liquid to a common shaft and disposing them in a common pressure jacket.

The problem facing the present invention is to ensure that the use of a Pelton turbine does not have any other effects, such that the integrated Pelton turbine operates in a pressure-free manner. This is because if the Pelton turbine is not operated under pressureless conditions, the Pelton turbine itself cannot function fully. That is, although Pelton turbines have very good performance, if liquid remains in the blades of the Pelton turbine, there is a risk that the liquid will destroy the Pelton turbine. In other words, if the liquid that drives the Pelton turbine blades does not flow out immediately, and the liquid builds up in the jacket to a level that submerges the blades,
The jet hits the blades and destroys them. Therefore, in the past, the pleton turbine was arranged separately and the liquid was discharged under no pressure without being pressurized, but in the present invention, the pleton turbine and the circulation pump are commonly used. The circulation pump is placed in a pressure jacket to allow the Pelton turbine to ideally operate under pressureless conditions. The liquid is drained into a deep tank from where it is returned to a source of liquid storage, for example the ocean. By placing the circulation pump that pumps the liquid back on the same shaft and in the same pressure jacket, the various electrical disconnection mechanisms required when the circulation pump is installed separately are eliminated. between the pump and the Pelton turbine as well as between the Pelton turbine and the Pelton turbine.
It is no longer necessary to provide bulky sealing devices between the turbine and the atmosphere. In combination with the ability to eliminate frictional losses in the shaft sealing device, the efficiency of the Pelton turbine can be increased, and it is electrically driven.
There is no need for any additional equipment that must be locked in conjunction with the circulation pump/turbine combination unit.

The circulation pump/turbine combination unit of the present invention allows liquid to be pumped back from a deep receiving tank to be easily drawn in while the unit is in operation. When properly dimensioned, the feeding conditions are otherwise essentially the same. This is because the rotational speed always changes synchronously with the frequency or in a manner adapted to the operation of the diesel drive used. Therefore, no water can penetrate into the casing of the Pelton turbine, so that no water impact occurs and, as a result, there is no risk of wearing out the turbine impeller.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the configuration of a circulation pump/turbine composite unit according to the present invention will be described in detail with reference to the accompanying drawings.

The composite unit according to the invention is composed of a multistage circulation pump 1 which serves to generate pressure, a Pelton turbine 2, and a spiral casing circulation pump 3 which serves to circulate liquid. A shaft 4 common to the circulation pumps 1 and 3 and the Pelton turbine 2 is provided. 3 for said circulation pumps 1, 3 and Pelton turbine 2;
The two casings are connected together to form a common pressure jacket.

The arrows indicate the flow path of the liquid from the inlet where the liquid enters, through the circulation pump 1 which functions to generate pressure, and from the circulation pump 3 which functions to reflux the liquid to the outlet. The liquid is supplied from the circulation pump 1 as indicated by the arrow to a module 5 in which a part of the liquid is separated as a product and another part is sent to the Pelton turbine 2.

On the other hand, the pressure inside the casing of the Pelton turbine 2 is approximately equal to atmospheric pressure. That is, the pump pressure is applied to the constriction part 9 (cylindrical member 7 and sleeve 8) located between the casing of the circulation pump 1 and the casing of the Pelton turbine 2.
However, since the internal space of the Pelton turbine 2 is communicated with the atmosphere via a vent valve, etc., the Pelton turbine 2 is free of pressure. operates below. The pressure energy contained in the section of the turbine 2 is also converted by the Pelton turbine 2 into mechanical energy which drives the circulation pump-turbine combination unit. Meanwhile, liquid is discharged from the Pelton turbine 2 into a pressureless deep-bottomed tank 6, and the fluid passes through a spiral casing pump 3 adapted to rotate together with the turbine 2, and then passes through a helical casing pump 3 adapted to rotate together with the turbine 2. The liquid is sent back to a reservoir source (eg the ocean).

By implementing the present invention as described above, the efficiency of the circulation pump/turbine composite unit can be greatly improved. In addition, the discharge of liquid from the Pelton turbine is carried out under pressureless conditions without pressurization by means of a circulation pump disposed in a common jacket with the Pelton turbine and serving to send the liquid back. Therefore, this Pelton turbine can function perfectly under ideal conditions. In addition, since the circulation pump which functions to generate the pressure, the circulation pump which functions to send back the liquid, and the Pelton turbine are mounted on a common shaft and are disposed within a common pressure jacket, the circulation pump can be operated separately. It also eliminates the need for bulky seals between the pump and the Pelton turbine, and between the Pelton turbine and the atmosphere. The efficiency of the Pelton turbine can be increased by eliminating friction losses with the stop device.

[Brief explanation of drawings]

The accompanying drawings are cross-sectional views illustrating the formation of a combined circulating pump and turbine unit according to the present invention. 1... Multi-stage circulation pump, 2... Pelton turbine, 3... Spiral casing type circulation pump, 4...
...Shaft, 5...Module, 6...Tank,
9...Aperture section.

Claims (1)

[Claims] 1 used in particular in seawater desalination plants, comprising a circulation pump serving to generate pressure and a turbine mounted on the same shaft as said circulation pump to recover the energy contained in the liquid flowing back In a circulation pump/turbine composite unit, a circulation pump 1 includes a Pelton turbine 2 and a circulation pump 3 that functions to send liquid back to its storage source, and that functions to generate pressure.
and the Pelton turbine 2 and a circulation pump 3 that serves to send back liquid are attached to a common shaft 4, and the circulation pumps 1, 3 and the Pelton turbine 2 are disposed in a common pressure jacket. , the casing of the circulation pump 1 and the casing of the Pelton turbine 2 communicate with each other via the constriction 9, and the interior of the Pelton turbine 2 substantially communicates with the atmosphere, so that said circulation pumps 1, 3 A circulating pump/turbine composite unit characterized in that a Pelton turbine 2 is operated in a pressureless state together with a Pelton turbine 2.