JPS6272999A - Method of adjusting heating value of city gas or the like - Google Patents

Abstract

PURPOSE:To reduce the number of vaporizers and to simplify the installation of a gas line, by providing such a process that LPG having been precooled to a temperature near the liquefied temperature of LNG is mixed with LNG in an LNG tank, and thereafter the thus obtained mixture liquid is evaporated. CONSTITUTION:LPG is introduced from an LPG tank 2 into a heat-exchanger 4 where LPG is cooled down to a temperature near to the liquefied temperature of LNG, and is then introduced into an LNG tank 1. LPG gas whose flow rate is adjusted by a control valve 10 is mixed with LNG and the thus obtained mixture liquid having a heat value adjusted to a desired value is led into a communication pipe line 7 by means of a pump 12. The mixture liquid in the pipe 7 is evaporated by only one vaporizer 6 into gas which is then fed into a supply system of city gas or the like.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is a method for vaporizing liquid-liquid mixed liquefied natural gas (hereinafter referred to as LNG) and liquefied petroleum gas (hereinafter referred to as LPG). This article relates to a method for adjusting the amount of heat in cities such as Su.

[Conventional technology]

In general, city gas etc. supplied by gas companies is a mixture of gas produced from coal, naphtha, purchased gas, LNG, LPG, etc. and adjusted to the calorific value specified in the supply regulations. .

In the case of LNG, which is used in the largest quantity these days,
In order to increase the calorific value of LNG to a desired amount, various methods have been used to mix LNG with LNG.

Typical methods include a method in which LNG is vaporized and gasified, and LPG is vaporized and mixed with this in a sous gas state; There is a method of mixing in the state.

The former is a method that vaporizes LPG for heat increase and mixes the two with LNG that has been vaporized.
In addition to requiring high-temperature thermal energy to vaporize LPG, it also requires equipment such as heat exchangers and heat quantity regulators, which increases variable costs and equipment costs, making it economically disadvantageous.
Since LPG is mixed in liquid form, there is no need for the energy required to directly vaporize LPG, but atomized LPG is mixed into the natural gas obtained by vaporizing LNG and vaporized by the sensible heat of the natural gas. Therefore, as the atomized LPG is vaporized, the temperature of the natural gas is lowered, and therefore, the mixing ratio is limited to a certain range.

[Problem that the invention seeks to solve]

The present invention has a large mixing ratio of LPG to LNG K, which expands the range of heat increase, eliminates the need for large-scale equipment such as a heat exchanger or heat regulator, and furthermore,
Even if the PG dispensing system shuts down due to some kind of trouble, it can be handled with the mixed liquid stored in the LNG tank in advance. The purpose is to provide a method that allows for easier adjustment of the amount of heat.

[Means for solving problems]

In order to solve the above problems, the present invention provides a, LN
After mixing LPG that has been pre-cooled to a temperature close to the liquid temperature of G with LNG in an LNG tank, (b) vaporizing the mixed liquid and producing city gas etc. that has been adjusted to the desired calorific value. be.

The present invention will be described below based on embodiments with reference to the drawings.

〔Example〕

The LNG and LPG applied in this example are as follows. That is, (1) First, LNG has a calorific value of 10 + 200 kazl
/Nrn3. Boiling point -160℃ (latm) (11) Also, LPG is heat! 24,000 kJ
/ Nm3. The boiling point is -42°C (latm).

FIG. 1 is an explanatory diagram showing the method of the present invention. Closed type L
The NG tank 1 may be either an above-ground type or an underground type, but is usually located near the top? It has a small tube of oil-off gas (not shown). LPG enters the heat exchanger 4 through the conduit 3 extending from the similarly closed LPG tank 2.
This heat exchanger cools the LNG to near the liquid temperature, and then it flows into the LNG tank 1 through the mixing nozzle 5. The heat source of the heat exchanger 4 is LNG led to a conduit 8 from a heat-regulated LNG tank (not shown).
After the PG has been cooled and vaporized, the supply is sent to the gas conduit 9 for mixing with the gas.

The expected heat increase based on the mixing of LPG with LNG is L
It is measured from the density measurement value of the mixed liquid by a density meter (not shown) installed in the NG tank 1.

The inflow of LPG is controlled by a valve 10 that opens and closes in response to the measured value. Further, the flow of LNG into the heat exchanger is controlled by a valve 11 that opens and closes in conjunction with the valve 1o.

In this way, the liquid-liquid mixture of LNG and LPG adjusted to the desired amount of heat increase is delivered to the conduit 7 by the bomb 7612, reaches the paperizer 6, is vaporized, and is sent to a supply system such as city gas.

〔Effect of the invention〕

The present invention is based on the above configuration, and only one P1/4 live unit is required, and the heat transfer area is also reduced in total, resulting in a significant reduction in equipment costs and variable costs. Also, L
Since a mixed liquid of NG and LPG is vaporized, it has many advantages, such as requiring only one paperizer, simplifying the system, and increasing reliability.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of an apparatus for carrying out the heat amount adjustment method according to the present invention. 1... LNG tank, 2... LPG tank, 4...
・Heat exchanger, 5...Mixing nozzle, 6...Paperizer, 10.11...Ba rep.

Claims (1)

[Claims] The method is characterized in that liquefied petroleum gas pre-cooled to a temperature close to that of liquefied natural gas is mixed with liquefied natural gas in a liquefied natural gas tank, and then the mixed liquid is vaporized to obtain city gas etc. whose calorific value is adjusted to a desired value. How to adjust the amount of heat of city gas, etc.