JPS5951112A - Lng heat utilized generating set - Google Patents

Abstract

PURPOSE:To make an almost fixed quantity of liquefied natural gas feed continualy with lesser cost as well as yet narrower space, by installing an LNG pressure regulating valve, which regulates the LNG pressure inside a condenser according to the temperature of seawater, in LNG piping at the downstream side of a medium condenser. CONSTITUTION:A Rankine cycle is composed of a medium condenser 1, a medium pump 2, a medium evaporator 3 and a medium turbine 4. An LNG pressure regulating valve 8 is installed in LNG piping at the downstream side of the medium condenser 1, and according to the evaporating capacity of the medium evaporator 3, namely the temperature of seawater and the flow of LNG, the LNG pressure inside the condenser 1 is regulated. Thus an almost fixed quantity of natual gas feed can be continued throughout the year with lesser cost as well as yet narrower space.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a power generation system using I, NO cold energy.

FIG. 1 shows a conventional Rankine cycle using an intermediate heat medium (hereinafter simply referred to as the medium). In Fig. 1, 1 is a medium condenser (hereinafter abbreviated as condenser), 2 is a medium bomb, 3 is a medium evaporator, 4 is a medium turbine, 5 is a H-G evaporator, and 6 is an LNG flow control valve. . Also, medium evaporator 3 and L
The heat flowing through the NG evaporator 5 is +'frt water, but the seawater temperature changes depending on the season. Focusing on the medium evaporator 3, the question is what seawater temperature is optimal to select as a design point. Now, if the medium is designed at an intermediate seawater temperature between summer and winter, 1 < generator ff. Considering this, in winter, if σ water vortex is lowered by ↓X5 at a fixed time, the evaporation capacity of the medium evaporator is insufficient. Therefore, it is necessary to reduce media flow without reducing I, No flow. However, in general, there are thermal power plants and city gas supply facilities that use NO as fuel downstream of LNG and %i heat utilization optical systems, so such operations are not recommended.
From the standpoint of stable supply of gas, this is an extremely inconvenient darkness. In addition, there will be times when the amount of LNG will be reduced by 3iL.
In order to do so, the generator must be large enough to evaporate even the lowest gL of seawater with a margin. However, the proportion of cost and space that the medium evaporator occupies in the entire plant is unmatched, and this arrangement is extremely wasteful for the entire refrigeration plant, both in terms of installation space and cost. .

The present invention has been made in view of these circumstances, and has seven aspects:
The aim is to provide LN with a stable supply of NG throughout the year with low manufacturing costs or construction space.
The first thing to be done is to provide a power generation device using cold energy.

An embodiment of the present invention will be described below with reference to the drawings. In FIG. 2, 1 is a medium condenser, 2 is a medium pump, 3 is a medium evaporator, 4 is a medium turbine, 5 is an LNG evaporator, and 6
J-j I, NG flow control valve, 7 is LNG surgical pressure pump,
8 is an LNG pressure control valve.

The present invention consists of the above-mentioned features, and its effects can be summarized as follows.
This will be explained below using figures. The 31st odor is L in the condenser l
It is a curve diagram showing the state of NG using isobar lines, the vertical axis is the enthalpy of LNG, and the horizontal axis is the temperature of LNG, Pl, P.
t is the LNG pressure (Pt>p+).

Also, T is the inlet LNG temperature of condenser 1, and T2 is condenser 1
The exit LNG temperature, T, is the medium condensation temperature. LNG
When the pressure of is as low as Pl, L inside the condenser 1
NG's enthalpy Kukasho, Ham■ and Kali, LNG here
If the flow rate is G, LNG used for condensing the medium
N hot/cool is expressed as G×△I. On the other hand, when the pressure of LNG is high like Pt, the LNG cooling and heating temperature used for LNG in the condensing RM device becomes G×Δ■′.

Here, 7H7p6 of the Rankin rifle flowing body is equal to the medium condenser, and the medium condensation 1 has the medium condensation i
It is proportional to the amount of LNG used for NIM.

Therefore, it can be seen that by controlling the pressure of LN(), it is possible to indirectly control the flow rate of the medium. In other words, in winter, when the seawater temperature is low and the evaporation capacity of the medium evaporator 3 decreases, the LNG pressure is increased and the flow rate of the medium is reduced. It is possible to continue flowing 5 volumes of water.

In the example shown in FIG. 2, the LNG pressure is 1°C.
Although the case where the node [8] is located on the L'flL side below the LNG evaporator 5 is shown, the present invention
It can also be applied to the case where it is located between the G evaporator 5 and the G evaporator 5.

As described above, according to the present invention, LNG Fi: force adjustment Jr. is installed in the LNG piping on the downstream side of the medium condenser (support), and the LNG Fi: force adjustment Jr. By adjusting the LNG pressure in the condenser, it is possible to create a power generation system using LNG cold energy that can continue to supply a substantially constant amount of NG air every year at lower costs and in a smaller installation space. .

[Brief explanation of drawings]

FIG. 1 is a system diagram showing a conventional Rankine cycle, FIG. 2 is a system diagram showing an embodiment of the present invention, and FIG. 3 is a curve diagram for explaining the behavior of LNG in a condenser. 1... Medium condenser, 2... Medium pump, 3... Medium evaporator, 4... Medium turbine, 5... LNG evaporator, 6... LNG flow M. M Sesuke, 7...LNG! A pressure pump, 8・LN (J pressure control valve, (7317) Agent Bl' Physician, close aide, Yu (eye or 1 person) Shi every water
Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] In a power generation system using LNG cold energy, LNG is used as a cold heat source for the condenser of the Rankine cycle.
A power generation device utilizing cold energy in the UshiG cold energy system, characterized in that the G pipe is provided with a control valve having a function of regulating the pressure of the LNG in the condenser according to the seawater temperature.