JPS6117201Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of the gas venting piping of the intermediate heat medium circulation pump of a liquefied natural gas (LNG) cold-thermal power generation device.

The power generation device using LNG cold energy will be described below with reference to Fig. 1, which shows an example of the present invention. A condenser 2 for an intermediate heat medium (e.g., propane) equipped with an LNG vaporizer 1 is connected to a pump 3 (e.g., a submerged vertical pump) on the liquid side.
The gas pump is connected to the evaporator 4 via a gas vent pipe. The gas side of the evaporator 4 is connected to the inlet side of a turbine 5 of a generator, and the outlet side of the turbine 5 is connected to the gas side of the condenser 2. The pump is provided with a gas vent pipe, the other end of which is connected to the gas side of the condenser.

In such a power generation device, the intermediate heat medium is normally stored in the evaporator 4 and heated by seawater 6. When starting the turbine 5, LNG 7 is introduced into the vaporizer 1 at a constant speed, and the intermediate heat medium in the condenser 2 is condensed by its cold heat, and the internal pressure gradually decreases. At this time, the pump 3 is stopped, and the nozzle of the turbine 5 is also fully closed. When the pressure of the condenser 2 reaches a predetermined value, the turbine nozzle is opened to a predetermined degree,
An intermediate heat transfer medium flows into the turbine and drives the turbine generator. Turbine exhaust goes to condenser 2
It is condensed and changed by the cold heat of LNG. In this way, the intermediate heat medium in the evaporator 4 moves to the condenser 2 side, and the liquid level in the condenser 2 gradually rises. Meanwhile, during this time, the amount of LNG introduced into the vaporizer 1 is increased at a constant rate, thereby further reducing the pressure in the condenser 2. When this pressure decreases to a predetermined value, the pressure in the condenser 2 is controlled to a constant value by the turbine nozzle. In the process of decreasing the pressure of the condenser 2, a part of the condensed intermediate heat medium evaporates, and gradually the decompression side equipment (condenser 2, pump 3,
(pipes, etc.). Next, when the liquid level of the intermediate heat medium in the evaporator 4 reaches a predetermined value, the pump 3 automatically starts to supply the liquefied intermediate heat medium in the condenser 2 to the evaporator 4, and the liquid level in the evaporator 4 is controlled to a constant value. The pump gas venting pipe is provided to return the vaporized intermediate heat medium generated during the decompression period to the condenser 2.

By the way, conventional pump degassing piping is comprised of pipes of the same size, first having a horizontal part and then having a vertical part. Therefore, a gas-liquid two-phase flow tends to occur in the horizontal piping section, and a bubble flow tends to occur in the vertical piping section. Therefore, if a large amount of liquid in the pump 3 evaporates as described above, the gas in the pump pot will not escape quickly, causing a phenomenon in which the pump body will not be filled with liquid when starting the pump 3, causing the pump to run dry. There is a possibility that If such a situation occurs, the liquefied intermediate heat medium in the condenser 2 will not be supplied satisfactorily to the evaporator 4, making it impossible to maintain the liquid level in the evaporator 4 at a constant value, which will impede the operation of the turbine generator. It starts to come.

The present invention was devised in order to solve this problem, and its feature is that the gas venting pipe is first inclined upward from the pump and then arranged vertically at a large diameter to connect it to the condensing means. There is a particular thing.

A specific example will be explained based on FIG. 1. First, the pipe 8 from the pump is inclined upward at about 45 degrees, for example, so that bubbles flow quickly. Next, the diameter of the vertical piping section 9 is increased to facilitate separation of gas and liquid. Therefore, the pump gas can easily escape to the condenser 2 through these gas vent pipes,
The pump body is filled with liquid to prevent the pump from running dry.

[Brief explanation of the drawing]

FIG. 1 is a flow sheet showing an example of the present invention, in which 1 is an LNG vaporizer, 2 is an intermediate heat medium condenser,
3 is the pump, 4 is the evaporator, 5 is the generator turbine, and 8 and 9 are the gas vent pipes.

Claims (1)

[Scope of utility model registration request] Liquefied natural gas cold-thermal power generation uses the vaporization of liquefied natural gas to evaporate the condensed intermediate heat medium, supplies it to the turbine of the generator, uses it to drive it, and then recycles it to vaporize the liquefied natural gas. In the apparatus, a gas venting pipe of a pump that sends the intermediate heat medium from the condensing means to the evaporating means is first inclined upward from the pump, and then vertically arranged at a large diameter and connected to the condensing means. Gas vent piping featuring