JPS6331039B2 - - Google Patents

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to an air-temperature evaporator that vaporizes liquefied gas at low temperatures, and is particularly used for liquefied gases whose consumption fluctuates rapidly (liquefied petroleum gas, ammonia, liquefied carbon dioxide). gas, etc.)
The present invention relates to an evaporator suitable for supplying.

(Prior art) Generally, in factories or residential complexes that consume large amounts of LPG, liquid LPG stored in storage tanks or LPG filled in containers is vaporized in an evaporator and supplied under a predetermined pressure. . There are two types of evaporators used in such cases: one that uses hot water as a heat source to forcefully vaporize it, and the other that uses atmospheric temperature as a heat source, but the former method not only requires a separate heat source but also requires maintenance. The operation is complicated. For this reason, in recent years, air-heated evaporators that use atmospheric heat as a heat source have come into widespread use in order to save energy. An air-heated evaporator is composed of a large number of fin pipes, and has the advantage of not requiring a separate heat source.
Unlike the method of forcibly supplying a heat source, there is a difficulty in continuously supplying gas. In other words, since an air-heated evaporator uses atmospheric heat, the LPG is depressurized and introduced into the evaporator after its boiling point is lowered to increase the temperature difference, so the fin pipe is cooled and the moisture in the atmosphere is removed. Ice builds up on the pipe. This freezing starts from the fin pipe near the liquid inlet and gradually develops, but as this develops, it causes a decrease in evaporation capacity, and as the evaporation function deteriorates significantly after long-term use, it is usually Either the liquid supply is stopped and the ice is removed using hot water, steam, etc., or the evaporator is divided into a liquid evaporating section and a heating section, and two sets of liquid evaporating sections are provided and used alternately.

(Problem to be solved by the invention) However, even in the case of the method of switching and using the liquid evaporator,
The development of ice is affected not only by atmospheric temperature and evaporation, but also by the weather, which can lead to errors in judgment, and detecting gas temperature and automatically switching will increase equipment costs. Become. Furthermore, although there is no problem for demand customers whose gas consumption remains constant, it is not possible to adequately respond to cases where the consumption fluctuates significantly. For example, when supplying LPG to residential complexes, not only does the demand for gas never completely disappear, just like with city gas, but there is also a large disparity in the amount of demand at different times of the day, and the general pattern is that the peak time is around meal times. Although it is self-evident that 70-80% of consumption occurs during dinner, it is said that 20-30% is consumed at other times. Therefore, in order to stably supply gas at the maximum peak time, a liquid evaporation section having an evaporation capacity corresponding to the peak time is required.
For this reason, conventionally, it has been common to install an evaporator with two sets of liquid evaporation sections that match the consumption at peak times, but this inevitably leads to an increase in the size of the device.
Considering non-peak hours, this means that the equipment is extremely inefficient and oversized.

(Means for Solving the Problems) The present invention was proposed in view of the above, and it is possible to easily switch the liquid evaporating section, and to increase the size of the liquid evaporating section to match the consumption at peak times. The feature is that two sets of liquid evaporators each have a liquid supply header pipe at the bottom of the finch tube block and a gas collecting pipe at the top. ,
A branch pipe connected to the liquid supply pipe and equipped with a liquid supply valve is connected, and the gas collecting pipe and a heating part for heating the liquefied gas vaporized in the liquid evaporation part are connected via a gas outlet pipe. In an air-temperature type evaporator that is connected to the above two sets of liquid evaporators, a gas-liquid gas is connected to the gas collecting pipe at the upper part and to the liquid supply header pipe through the liquid balance pipe at the lower part. A separation tank is provided, and the balance pipe is attached to the gas-liquid separation tank at a position that is about ⅓ or more from the bottom of the liquid evaporation section to the top.

(Example) The details will be explained below with reference to the figures. The figure shows an example of the device of the present invention using a system diagram.
Reference numeral 1 designates the evaporation section of the LPG evaporator, which is composed of a finch tube block 2, a liquid supply header pipe 3 provided at the bottom of the block 2, and a gas collecting pipe 4 provided at the top. Further, numeral 5 denotes a heating section in which a large number of finch tubes 6 are arranged in series by curved pipes 7, respectively. Next, 8 is a liquid sending pipe connected to a storage tank (not shown), for example, and the liquid sending pipe 8 is connected to the liquid evaporating section 1A provided in the two sets.
and 1B are connected via branch pipes 9 to the liquid supply header pipes 3A and 3B, respectively. 10 is a supply valve provided in each branch pipe 9, 11 is a gas-liquid separation tank, and the lower part of the tank 11 is a liquid balance pipe 12A and 12
B communicates with the liquid supply header pipes 3A and 3B of each liquid evaporation section 1A and 1B, respectively. The mounting positions of the liquid balance pipes 12A and 12B attached to the lower part of the gas-liquid separation tank 11 are the liquid evaporation parts 2A and 2.
It may be anywhere from the bottom to the top of B, but substantially from about 1/3 to the top. Further, the upper part of the gas-liquid separation tank 11 communicates with the aforementioned gas collecting pipes 4A and 4B, respectively, and also communicates with the gas outlet pipe 1.
It is connected to the heating section 5 via 3. Note that 14 is a gas outlet pipe.

In the above configuration, if 1A of the two sets of liquid evaporators is used and 1B is reserved, LPG from the liquid feed pipe 8 will be transferred to the supply valve 10 from the branch pipe 9A.
A, where the pressure is reduced to, for example, 0.9 Kg/cm ² and then sent to the liquid supply header pipe 3A. Next, the gas is introduced into a large number of finch tubes 2A in a distributed manner, and is vaporized by atmospheric heat while rising through the tubes 2A. This gas is collected in the gas collecting pipe 4A and introduced into the gas-liquid separation tank 11. The gas introduced into the gas-liquid separation tank 11 enters the heating section 5 through the gas introduction pipe 13 and is further heated as it flows through the finch tube 6, reaches a predetermined gas temperature, and is led out through the gas outlet pipe 14. The gas is supplied by a gas supply pipe connected to the outlet pipe 14.

In this type of use, the finch tube block 2A is initially covered with soft, thin frost-like ice, which becomes hard and thick ice over time, and this frozen portion gradually develops as it is used continuously for a long period of time. As the process starts from the bottom of the finch tube 2A and proceeds to the top, the liquid evaporation capacity decreases and the introduced liquid cannot be completely vaporized. In other words, the liquid is mixed into the gas introduced into the gas-liquid separation tank 11, but in conventional devices, the temperature is determined empirically based on the frozen state of the finch tube 2A, or by detecting the gas temperature at the outlet of the liquid evaporator. When the temperature drops below the temperature, the liquid supply is switched from the main flow A side to the backup B side. However, if such switching were to be performed manually, constant monitoring would be required. In addition, as mentioned above, the development of freezing depends on the atmospheric temperature,
Since it is affected not only by the amount of evaporation but also by the weather, it is possible to make a mistake in judgment, and detecting the gas temperature and automatically switching will increase equipment costs.
Furthermore, in usage situations where a large amount of liquid is consumed in a short period of time, as mentioned above, one of the liquid evaporators must be stopped for thawing, so the evaporation area must be large enough to accommodate the maximum amount used. Therefore, it was necessary to provide two sets of liquid evaporating sections, making it necessary to increase the size of the device.

In the device of the present invention, when liquid is currently being sent from the liquid supply valve 10A to the liquid evaporator 1A, if the capacity of the liquid evaporator 1A decreases due to continuous use for a long time and the liquid level in the finch tube 2A rises, the air Unevaporated liquid is mixed into the gas introduced into the liquid separation tank 11, but the liquid is separated in the tank 11, introduced into the liquid supply header pipes 3A and 3B through the liquid balance pipes 12A and 12B, and evaporated. be done. When the evaporation capacity of the liquid evaporator 1A further decreases, the liquid level in the finch tube 2A rises accordingly, but the liquid balance tubes 12A and 12B are installed at a predetermined position, specifically at the lower part of the gas-liquid separation tank 11. When it reaches the tank 1
The liquid separated in step 1 does not flow to the liquid balance pipe 12A, but flows from the liquid balance pipe 12B to the liquid supply header pipe 3B, ascends the finch tube 2B, and is evaporated. That is, at this point, evaporation and gas supply are performed from 1B in addition to liquid evaporation section 1A, but intermittent evaporation and gas supply from 1B are not continuous evaporation and gas supply.
When the gas supply state is reached (this state can be easily confirmed, for example, by the constant deposition of ice on the lower part of the liquid evaporation section 1B), open the liquid supply valve 10B,
10A is closed and the liquid is supplied to the liquid evaporator 1B side,
1A is in a standby state and thawing is performed. Therefore, the problems encountered in the conventional device described above during switching can be easily solved.

The device of the present invention is constructed as described above, but it is particularly advantageous because the evaporation area can be reduced to about half when there is demand fluctuation such that 70 to 80% of the daily demand is concentrated around dinner time. is effective. The embodiment will be explained below. Two sets of liquid evaporating sections 1A,
Let the total evaporation area of 1B be the area corresponding to the maximum demand. That is, the evaporation area is about half that of the conventional device, and the liquid is sent to the liquid evaporation section 1A in the same manner as described above. Until the evening of the maximum peak time, the daily demand is
Since it is 20 to 30%, it can be supplied sufficiently with only 1A, there is little freezing, and there is almost no decline in evaporation function even in winter. When the maximum peak time is reached in such a state, a large amount of liquid is supplied in a short time, so the liquid level in the 1A finch tube rises and reaches the installation position of the liquid balance pipe 12 of the gas-liquid separation tank 11 as described above. Then, the liquid evaporates by the cooperation of the liquid evaporators 1A and 1B. Eventually, the maximum peak time passes and the voltage drops to 1A.
The liquid level in the finch tube has decreased, and no liquid flows into 1B, leaving only 1A, and the 1B side will not be used until the next day's maximum peak time, and the soft and thin frost-like ice that has formed during that time will be melted. be done. On the other hand, in the 1A liquid evaporation section, by repeating the above usage pattern, the initially frosty, soft and thin ice becomes hard and thick ice.
This frozen part gradually develops from the lower part to the upper part, and if it is used continuously for more than one week in winter, for example, it will not be able to meet the maximum peak demand, so the liquid supply is switched to the liquid evaporating part 1B and the same embodiment as described above is repeated.

(Effects of the Invention) The device of the present invention has a simple configuration as described above, and it is possible to implement an embodiment in which all two sets of liquid evaporators can be used. There is no need to configure it in time. Therefore, there is an advantage that the liquid evaporating section is only about half as large as that of the conventional device. Further, the transition from the liquid evaporating section 1A to 1B during gas feeding is automatically performed by the liquid in the finch tube 2A flowing into the 1B side through the gas-liquid separation tank 11, as described above. ,
Compared to a device that has an automatic switching control device that combines a liquid level detector, temperature sensor, control valve, etc., there is no need to worry about maintenance, and it has many features and effects, such as being able to provide a stable gas supply. It is.

[Brief explanation of drawings]

The figure is a system diagram showing an embodiment of the device of the present invention. DESCRIPTION OF SYMBOLS 1...Liquid evaporation section, 2...Finch tube block, 3...Liquid supply header pipe, 4...Gas collecting pipe, 5...Heating section, 11...Gas-liquid separation tank, 12...
...Liquid balance pipe, 13...Gas introduction pipe.

Claims (1)

[Claims] 1 A liquid supply header pipe connected to each of the liquid supply header pipes of two sets of liquid evaporators each having a liquid supply header pipe at the lower part of the finch tube block and a gas collecting pipe at the upper part, and a liquid supply pipe An air-heating evaporator in which a branch pipe equipped with a valve is connected, and the gas collecting pipe and a heating section for heating the liquefied gas vaporized in the liquid evaporator are connected via a gas outlet pipe. In the vessel, a gas-liquid separation tank is provided between the two sets of liquid evaporating sections, the upper part of which is connected to the gas collecting pipe, and the lower part of which is connected to the liquid supply header pipe via a liquid balance pipe; An air-temperature evaporator characterized in that the balance pipe is attached to the separation tank from the bottom of the liquid evaporating section to about 1/3 or more of the way to the top.