CN218349809U

CN218349809U - C-type independent liquid cargo tank cold state evaporation rate measuring system

Info

Publication number: CN218349809U
Application number: CN202120030897.8U
Authority: CN
Inventors: 王璐玭; 樊涛
Original assignee: Jiangnan Shipyard Group Co Ltd
Current assignee: Jiangnan Shipyard Group Co Ltd
Priority date: 2021-01-07
Filing date: 2021-01-07
Publication date: 2023-01-20
Anticipated expiration: 2031-01-07

Abstract

The utility model provides a C type independent cargo tank cold state evaporation rate measurement system, C type independent cargo tank top is equipped with the air chamber, and C type independent cargo tank outer wall is equipped with the heat preservation insulating layer, C type independent cargo tank cold state evaporation rate measurement system is including setting up the thermal current sensor on the heat preservation insulating layer, the thermal current sensor passes through signal amplifier and connects in data recording device; the gas chamber is provided with a gas pressure detection device capable of detecting the pressure of the gas chamber; the utility model discloses can gather the independent cargo tank surface heat preservation insulating layer of C type and spread into the calorific value and the pressure value that the air chamber increases to calculate the vapour quality value because of the heat absorption increases according to the calorific value that spreads into, calculate corresponding vapour quality added value according to air chamber pressure added value, then calculate two kinds of vapour quality added values weighting and obtain more accurate vapour quality added value, then divide the vapour quality added value by the total quality of liquid goods and acquire the evaporation rate, and the measuring result is more accurate.

Description

C-type independent liquid cargo tank cold evaporation rate measuring system

Technical Field

The utility model belongs to the technical field of the liquefied gas carrier, concretely relates to independent cargo tank cold state evaporation rate measurement system of C type.

Background

At present, the world gas energy consumption and the demand of gas chemical raw materials are in a continuous rising trend, which brings great development opportunities for the development of liquefied gas transport ships (liquefied gas ships for short). Under the international situation, research and development efforts on liquefied gas ships are increased by ship design units.

The design and construction of cargo tanks is of central importance in the design and production of lng ships. The cold evaporation rate of the liquid cargo tank is related to the loading rate of the liquefied gas transported by the ship and the safety during sailing, and the cold evaporation rate of the liquid cargo tank is the basis for judging whether the design of the liquid cargo tank is reasonable and whether the production process reaches the standard. In order to ensure that the design and construction of the cargo tank of the liquefied gas carrier meet the expected requirements, the cold evaporation rate of the cargo tank needs to be measured. The C-shaped independent liquid cargo tank is a pressure container which can bear pressure and is widely applied to liquid cargo and gas ships. Because the temperature difference exists inside and outside the C-shaped independent liquid cargo tank, when external heat is transferred into the C-shaped independent liquid cargo tank, the internal energy of liquid cargo in the tank can be increased, and further partial liquid phase is evaporated to be changed into gas phase, so that the pressure in the C-shaped independent liquid cargo tank is increased, the existing evaporation rate measuring system generally adopts a gas mass flowmeter to measure the steam flow to calculate the evaporation rate, but the C-shaped independent liquid cargo tank is a pressure container, so that the measuring precision of the gas mass flowmeter can be influenced, and the accuracy of the evaporation rate is further influenced; in addition, the steam needs to be collected and processed after passing through the gas mass flow meter, otherwise, the steam is discharged to the outside of the measuring system through the gas mass flow meter, and when the steam is flammable and explosive substances, not only the environment is polluted, but also the risk of combustion and explosion exists, so that the cost of the measuring system is increased.

SUMMERY OF THE UTILITY MODEL

In view of the above prior art's shortcoming, the utility model aims to provide an independent cargo tank of C type cold state evaporation rate measurement system can conveniently accurately measure the cold state evaporation rate of the independent cargo tank of C type.

In order to achieve the above and other related objects, the present invention provides a system for measuring the cold state evaporation rate of a C-type independent cargo tank, wherein an air chamber communicated with the C-type independent cargo tank is arranged at the top of the C-type independent cargo tank, a heat insulation layer is arranged on the outer wall of the C-type independent cargo tank, the system for measuring the cold state evaporation rate of the C-type independent cargo tank comprises a heat flow sensor arranged on the heat insulation layer, and the heat flow sensor is connected to a data recording device through a signal amplifier; and the gas chamber is provided with a gas pressure detection device capable of detecting the pressure of the gas chamber. The utility model discloses can gather the independent cargo tank surface heat preservation insulating layer of C type and the pressure value that heat and air chamber increase into to calculate because of the steam quality of endothermic increase according to the heat value that spreads into, calculate corresponding steam quality added value according to air chamber pressure added value, then calculate two kinds of steam quality added values in a weighted manner and obtain more accurate steam quality added value, then divide the steam quality added value that obtains in a weighted manner with the total quality of liquid goods and acquire the evaporation rate, and measuring result is more accurate.

Preferably, the heat flow sensor is connected to the signal amplifier via a low temperature-resistant electrical line, and the signal amplifier is connected to the data recording device via a low temperature-resistant electrical line, so that transmission of low temperature impression signals from the C-type individual cargo tank is avoided.

Preferably, the gas pressure detection device is a pressure gauge, and the pressure gauge is connected to the gas chamber through a vapor pipeline so as to display the pressure value of the gas chamber in real time.

Preferably, the measurement range of the pressure gauge is 0 bar-alpha bar, wherein alpha is not less than 120% of the design pressure value of the C-shaped independent liquid cargo tank, and the insufficient range of the pressure gauge is avoided.

Preferably, the contact area of the heat flow sensor and the heat insulation layer is not less than 5% of the area of the outer surface of the heat insulation layer; the installation height of the heat flow sensor is lower than the liquid level height of liquid cargo in the C-shaped independent liquid cargo cabin, so that the added value of the internal energy of the liquid cargo can be conveniently obtained.

As above, the utility model discloses an independent cargo tank cold state evaporation rate measurement system of C type has following beneficial effect:

the utility model discloses a cold evaporation rate measurement system of independent cargo tank of C type, can gather the calorific value that independent cargo tank surface heat preservation insulating layer of C type spreads into and the pressure value that the air chamber increases, the user can calculate because of the steam quality that the heat absorption increases according to the calorific value that spreads into, and calculate corresponding steam quality increase value according to air chamber pressure increase value, then calculate two kinds of steam quality weightings and draw more accurate steam quality increase value, and divide the steam quality increase value that the calculation of weighting obtains the evaporation rate by the total mass of liquid cargo, the measuring result is more accurate; in addition, the measuring device does not need to be moved, is not limited by the shape and the size of the C-shaped independent liquid cargo tank, has wide application occasions, does not need to be provided with a steam collecting and processing device, and reduces the system cost.

Drawings

Fig. 1 is the utility model discloses well independent cargo tank cold state evaporation rate measurement system schematic diagram of C type.

Description of the reference numerals

The device comprises a C-shaped independent liquid cargo tank 1, liquid cargo 2, an air chamber 3, a heat insulation layer 4, a heat flow sensor 11, a signal amplifier 12, a data recording device 13, a low temperature resistant electric lead 14, a gas pressure detection device 21 and a steam pipeline 22.

Detailed Description

The following description is given for illustrative embodiments of the present invention, and other advantages and effects of the present invention will be apparent to those skilled in the art from the disclosure of the present invention.

Please refer to fig. 1. It should be understood that the structure, proportion, size and the like shown in the drawings attached to the present specification are only used for matching with the content disclosed in the specification, so as to be known and read by those skilled in the art, and are not used for limiting the limit conditions of the present invention, so that the present invention does not have the substantial technical significance, and the modification of any structure, the change of the proportion relation or the adjustment of the size should still fall within the scope of the technical content disclosed in the present invention without affecting the function and the achievable purpose of the present invention. Meanwhile, the terms such as "upper", "lower", "left", "right", "middle" and "one" used in the present specification are for convenience of description, and are not intended to limit the scope of the present invention, and changes or adjustments of the relative relationship thereof may be made without substantial technical changes, and the present invention is also regarded as the scope of the present invention.

As shown in fig. 1, the cold evaporation rate measuring system for C-type independent liquid cargo tank of the present invention, wherein liquid cargo 2 with known mass is stored in the C-type independent liquid cargo tank 1, the top of the C-type independent liquid cargo tank 1 is provided with an air chamber 3 for collecting vapor of liquid cargo 2, the outer wall of the C-type independent liquid cargo tank 1 is provided with a heat insulation layer 4, the cold evaporation rate measuring system for C-type independent liquid cargo tank comprises a heat flow sensor 11, a signal amplifier 12, a data recording device 13 and a gas pressure detecting device 21 for detecting the pressure of the air chamber; the heat flow sensor 11 is installed on the heat insulation layer 4 and used for acquiring a heat flow density signal, because the heat flow density signal is a weak voltage signal, the heat flow sensor 11 is connected with the signal amplifier 12 through a low temperature resistant lead 14 so as to amplify the weak voltage signal to an observable voltage signal through the signal amplifier 12, and the signal amplifier 12 is connected with the data recording device 13 through a low temperature resistant lead 14 so as to transmit the amplified signal to the data recording device 13 for recording and processing; the gas pressure detection device 21 is a pressure gauge or a pressure sensor, and the gas pressure detection device 21 is communicated with the gas chamber 3 through a steam pipeline 22; in this embodiment, the gas pressure detection device 21 is a pressure gauge, and the measurement range of the pressure gauge is 0 bar- α bar, where α is not less than 120% of the design pressure value of the C-type independent cargo tank.

Further, the contact area of the heat flow sensor 11 and the heat insulation layer 4 is not less than 5% of the area of the outer surface of the heat insulation layer 4; the installation height of the heat flow sensor 11 is lower than the liquid level height of the liquid cargo 2 in the C-shaped independent liquid cargo tank 1, and in this embodiment, the installation height of the heat flow sensor 11 is located in the middle of the outer wall of the C-shaped independent liquid cargo tank 1.

When external heat is transmitted into the C-shaped independent liquid cargo tank 1, the temperature in the C-shaped independent liquid cargo tank 1 is increased, so that the middle part of the liquid cargo 2 is evaporated into a gas phase due to heat absorption, and the gas phase pressure is increased along with the increase of the gas phase quality.

The evaporation rate of the C-type independent liquid cargo tank 1 is measured by taking 24h as a limit, and the working principle is as follows:

(1) The liquid cargo 2 with known mass is stored in the C-type independent liquid cargo tank 1, signals collected on the heat insulation layer 4 are amplified by the heat flow sensor 11 through the signal amplifier 12 and then transmitted to the data recording device 13, the signals are continuously collected and recorded for 24h, the starting time and the ending time are recorded, then the average heat flow density of the heat insulation layer 4 in unit area is calculated, the total heat transmitted into the C-type independent liquid cargo tank 1 is obtained, the total heat transmitted into the C-type independent liquid cargo tank 1 is the heat absorption amount (namely the increment of the gas phase heat absorption amount) converted from the liquid phase to the gas phase, and the increment of the vapor mass is obtained through a thermodynamic formula;

(2) Meanwhile, the pressure gauge obtains the initial pressure value and the end pressure value of the air chamber 3 to obtain the pressure increment, and the pressure increment further obtains the vapor quality increment (namely the liquid cargo evaporation capacity);

(3) And (3) carrying out weighted calculation on the vapor mass increase value in the step (1) and the vapor mass increase value in the step (2) to obtain an actual vapor mass increase value, and dividing the actual vapor mass increase value by the total mass of the liquid cargo to obtain an actual evaporation rate.

In the whole measuring process, liquid cargos in the cabin are ensured not to shake, and the inaccuracy of a measuring result caused by the fact that the pressure in the cabin is changed due to shaking is avoided.

To sum up, the utility model discloses an independent cargo tank cold state evaporation rate measurement system of C type carries out the weight calculation with the evaporation rate size that the gas pressure conversion obtained and the actual heat absorption capacity of cargo tank reachs, can obtain more accurate evaporation rate measuring result, improves measurement accuracy, has reduced measuring error. The measuring system does not need to move the liquid cargo tank, is not limited by the capacity and the weight of the C-shaped independent liquid cargo tank, has wide application, does not need to be provided with a vapor collecting and processing device, and reduces the system cost.

The above embodiments are merely illustrative of the principles and effects of the present invention, and are not to be construed as limiting the invention. Modifications and variations can be made to the above-described embodiments by those skilled in the art without departing from the spirit and scope of the present invention. Accordingly, it is intended that all equivalent modifications or changes which may be made by those skilled in the art without departing from the spirit and technical spirit of the present invention shall be covered by the claims of the present invention.

Claims

1. A cold evaporation rate measuring system of a C-shaped independent liquid cargo tank is characterized in that the cold evaporation rate measuring system of the C-shaped independent liquid cargo tank comprises a heat flow sensor (11) arranged on a heat insulation layer (4), and the heat flow sensor (11) is connected to a data recording device (13) through a signal amplifier (12); and a gas pressure detection device (21) capable of detecting the pressure of the gas chamber is arranged on the gas chamber (3).

2. The cold evaporation rate measurement system for a C-type independent cargo tank according to claim 1, wherein the heat flow sensor (11) is connected to the signal amplifier (12) by a low temperature resistant electrical lead (14), and the signal amplifier (12) and the data recording device (13) are connected by a low temperature resistant electrical lead (14).

3. The cold evaporation rate measurement system of a C-type independent cargo tank according to claim 1, wherein the gas pressure detection means (21) is a pressure gauge connected to the gas chamber (3) through a vapor line (22).

4. The system of claim 3, wherein the pressure gauge measures from 0bar to α bar, where α is not less than 120% of a design pressure value for the type C tank.

5. The cold evaporation rate measurement system of a C-type independent cargo tank according to claim 1, wherein the contact area of the heat flow sensor (11) and the thermal insulation layer (4) is not less than 5% of the area of the outer surface of the thermal insulation layer (4); the installation height of the heat flow sensor (11) is lower than the liquid level height of liquid cargos (2) in the C-shaped independent liquid cargo tank (1).