JPS6062609A - Cold-heat power generating plant - Google Patents

Abstract

PURPOSE:To improve the reliability of a plant by providing both a pressure equalizing system communicating a turbine inlet-side piping with each pressure equalizing storage tank which is positioned higher than an evaporator and another system communicating a turbine outlet-side piping with the tank and installing a condensor at a higher level than the tanks. CONSTITUTION:Each of tanks 10a and 10b is installed higher than an evaporator 2 and furthermore, a condensor 1 is installed higher than the tanks 10a and 10b. There are independently provided a pressure equalizing system which communicates the inlet piping 13 of a turbine 3 with both the tanks 10a and 10b and is equipped with valves 14a and 14b and another pressure equalizing system which communicates the inlet piping 15 of the turbine 3 with the tanks 10a and 10b and is equipped with valves 14c and 14d. When the valve 14c is opened to equalize the inner pressure of the tank 10a to that of the turbine's outlet piping 15, the liquefied heat medium from the condensor 1 is stored in the tank 10a. On the other hand, when the valve 14b is opened to equalize the inner pressure of the tank 10b to that of the piping 13, the liquefied heat medium inside the tank 10b is forcedly sent to the evaporator 2 due to the head difference.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention 1] The present invention relates to an improvement in a cold power generation device used to convert and extract cold energy contained in low-temperature liquefied gas such as LNG into electrical energy.

[Background of the Invention J An example of a conventional cold power generation facility will be explained with reference to FIG. In Fig. 1, 1 is a heat medium condenser (hereinafter abbreviated as condenser);
2 is a heat medium evaporator (hereinafter abbreviated as evaporator), 3 is a heat medium expansion turbine (hereinafter abbreviated as turbine), and 4a is a condenser 1 that converts low-temperature liquefied gas such as LNG (hereinafter abbreviated as low-temperature liquefied gas). 4b is a pipe that sends the gas heated and vaporized by the condenser 1 to the outside of the system; 5 is a heat medium boost pump (hereinafter referred to as , pump), 7 is a pipe connecting the evaporator 2 and the turbine 3, 8 is a generator connected to the turbine 3, 9 is the turbine 3
This is a pipe that connects the condenser 1 and the condenser 1.

In such a configuration, first, the vaporized heat medium fed from the pipe 9 to the condenser 1 is cooled and liquefied by exchanging heat with the low-temperature liquefied gas fed from the pipe 4a in the condenser 1. The low-temperature liquefied gas is heated and vaporized by a heat medium, and then sent out from the pipe 4b to a place of use such as a power generation boiler (not shown). The liquefied heat medium passes through piping 6 and is increased in pressure to a predetermined pressure by pump 5, and then supplied to evaporator 2. The supplied liquefied heat medium is heated and vaporized by a heating source such as seawater in the evaporator 2, and the vaporized heat medium is sent to the turbine 3 through a pipe 7. The supplied vaporized heat medium is expanded by the turbine 3, and at this time, the cold heat held by the heat medium is converted into mechanical energy, and further converted into electrical energy by the generator 8. As a result, the vaporized heat medium whose temperature and pressure have decreased is sent to the condenser 1 again through the pipe 9.

Note that in actual operation, the above cycle is repeated and continued.

In the conventional cryogenic power generation device described above, in order to feed the heat medium liquefied in the condenser 1 to the evaporator 2, it is necessary to make the inlet pressure of the evaporator 2 higher than the inlet pressure of the turbine 3. A pump 5 is used as a means for this purpose. However, the use of pumps has the disadvantage that, although it depends on the scale of the cold power generation equipment, the power consumption by the pump is relatively large and uneconomical, as the amount of power consumed by the pump is several inches compared to the amount of cold power generation, and the operating costs are high. Also,
In this case, a liquefied gas pump is used because the heat medium is liquefied gas.However, liquefied gas pumps are expensive and require high equipment costs, and there is also a lack of track record and there are concerns about reliability. In many cases, a backup liquefied gas pump is installed in case of failure, which has the disadvantage of further increasing equipment costs.

[Object of the Invention] An object of the present invention is to provide a highly reliable cold-thermal power generation device.

[Summary of the Invention J The present invention provides a heat medium storage tank that connects a plurality of liquefied heat medium storage tanks between a heat medium expansion turbine outlet, a heat medium condenser pipe, and a heat medium supply pipe to a heat medium evaporator. Installed at a higher position than the evaporator, there is a separate pressure equalization system that connects the heat medium expansion turbine inlet piping and the liquefied heat medium storage tank, and a pressure equalization system that connects the heat medium expansion turbine outlet piping and the liquefied heat medium storage tank. , and further characterized in that the heat medium condenser is installed at a higher position than the liquefied heat medium storage tank.

[Embodiments of the Invention] Hereinafter, the present invention will be described in detail based on FIG. 2, which is a specific embodiment. In FIG. 2, devices with the same reference numerals as those in FIG. 1 are the same devices as shown in FIG. 1, and explanations thereof will be omitted. 10a, 10
b is a liquefied heat medium storage tank (hereinafter abbreviated as tank) installed in the middle of the pipe 6, in which liquid level gauges 11a and llb are installed, and check valves 12a to 12d are installed on the entrance and exit sides. . These tanks 10a, 10b are installed at a higher position than the evaporator 2, and the condenser 1 is installed at an even higher position than these tanks 10a, 10b. Moreover, the turbine 3 artificial piping 13 and the tank 10a.

10b, a pressure equalization system with valves 14a and 14b installed, turbine 3 outlet piping 15, and tanks 10a and 10b.
A separate pressure equalization system with valves 14c and 14d is provided. According to such a configuration, the liquefied heat medium from the condenser 1 passes through the pipe 6 and reaches the check valve 1.
2c and stored in tank 10a.

At this time, the valve 14c is opened to equalize the internal pressure of the tank 10a and the internal pressure of the turbine outlet pipe 15, thereby ensuring that the liquefied heat medium is fed to the tank 10a. Furthermore, in this case, since the internal pressure of the tank 10a is lower than the internal pressure of the pipe 6 on the evaporator 2 side, the check valve 12a closes to prevent the liquefied heat medium from flowing back from the evaporator 2 side. .

On the other hand, the liquefied heat transfer medium in the tank 10b is controlled by opening the valve 14b and equalizing the internal pressure of the tank 10b and the internal pressure of the turbine inlet pipe 13, and by using the check valve due to the head difference between the tank 10b and the evaporator 2. 12be, and is fed to the evaporator 2 through the pipe 6. Note that after that, one cycle is completed by passing through the same route and performing the same actions as in the conventional cold power generation equipment. When the above cycle is repeated and continued for a while, the liquid level in the tank 10a rises, and on the other hand, the liquid level in the tank 10b decreases.
When it is confirmed that the liquid level in either tank 10a or 10b has reached the upper or lower limit, close the valve 14c,
Valve 14a' (I-open and close valve 14b at the same time, valve 14
d to switch between tanks 10a and 10b. By this switching, the internal pressure of the tank 10a is changed to the turbine inlet pipe 1.
3, the liquefied heat medium stored in the tank 10a is supplied to the evaporator 2 through the check valve 12a' (il-) and the piping 6.
Since the internal pressure of b is equal to the internal pressure of the turbine outlet pipe 15, the liquefied heat medium from the condenser 1 is reliably delivered to the tank 10b through the pipe 6 and the check valve 12d and stored therein. As described above, good continuous operation is possible by alternately and appropriately switching between the tanks 10a and 10b.

Although the case where two tanks are installed has been described as an example, there is no particular problem even if more tanks are installed. In addition, although the tank switching point is checked using a liquid level gauge in this embodiment, other methods such as
It is also applicable to switch tanks at regular intervals using a timer or the like.

[Effects of the Invention J] As explained above, the present invention provides a liquefied heat medium storage tank and makes its installation height higher than the heat medium evaporator, thereby effectively heating the liquefied heat medium from the heat medium condenser. Since it can be fed to the medium evaporator, there is no need to install a liquefied gas pump, which is a heat medium pressure boost pump, and this has the effect of significantly reducing operating and equipment costs and improving reliability.

[Brief explanation of the drawing]

FIG. 1 is a system diagram showing an example of a conventional cold power generation facility, and FIG. 2 is a system diagram showing an embodiment of the cold power power generation facility according to the present invention. 1... Heat medium condenser, 2... Heat medium evaporator, 3...
- Heat medium expansion turbine, 5... Heat medium boost pump, 8
... Generator, 10a, 10b ... Liquefied heat medium storage tank, 11a, 1lb-Liquid level gauge, 12a, 12
b, 12c, 12d - check valve, 13-... turbine inlet piping, 14a, 14b, 14c. 14d... Valve, 15... Turbine outlet piping Figure 1 and Figure 2

Claims (1)

[Claims] 1. In a cold-thermal power generation device including a heat medium evaporator, a heat medium expansion turbine, a generator, and a heat medium condenser, from the outlet of the heat medium expansion turbine to a pipe passing through the heat medium condenser and to the heat medium evaporator. A plurality of liquefied heat medium storage tanks are installed at a position higher than the heat medium evaporator in the middle of the connection of the heat medium supply piping, and a plurality of liquefied heat medium storage tanks are installed at a position higher than the heat medium evaporator, and an equalizer connecting the heat medium expansion turbine inlet pipe and the liquefied heat medium storage tank is installed. A pressure system and a pressure equalization system connecting the heat medium expansion turbine outlet piping and the liquefied heat medium storage tank are each provided separately,
Furthermore, the cold-thermal power generation device is characterized in that the heat medium condenser is installed at a higher position than the liquefied heat medium storage tank.