Liquefied petroleum gas odorization automatic control device

Abstract

The utility model discloses a liquefied petroleum gas odorization automatic control device which is characterized in that liquefied petroleum gas is stored in an LPG storage tank, and the LPG storage tank is connected with an LPG gas cylinder through an LPG filling pipeline; a controller, a detection device and an execution mechanism are arranged in the odorization automatic control device; an odorant output pipeline connected with the LPG filling pipeline is arranged in the executing mechanism; the signal input end of the controller is connected with the output end of each sensor in the detection device, and the signal output end of the controller is connected with the execution mechanism. According to the utility model, the waste of odorant can be reduced, the use safety of liquefied petroleum gas is ensured, the automation level of the odorizing process is improved, and the practicability is strong.

Description

Technical Field

[0001] The utility model relates to the technical field of liquefied petroleum gas odorization, in particular to an automatic control device for liquefied petroleum gas odorization. Background Art

[0002] Liquefied petroleum gas (LPG) is a byproduct of petroleum extraction and processing. Composed primarily of propane, propylene, butane, and butene, it is inherently colorless and odorless. However, to ensure its safety, LPG must be odorized. This helps prevent leaks and allows for prompt action. Therefore, odorization is a crucial component of gas safety.

[0003] According to the national standards "GB 51142-2015, Specification for Design of Liquefied Petroleum Gas Supply Engineering," and "GB 11174-2011, Liquefied Petroleum Gas," when LPG is odorless or has insufficient odor, an odorant formulated with sulfur-containing compounds with a noticeable odor should be added. While the "CJJT148-2010, Technical Specification for Odorization of Urban Gas," provides detailed requirements for odorization control of urban pipeline natural gas, it lacks clear requirements for odorization control of bottled LPG, including guidance on odorant selection and odorization methods.

[0004] According to a survey of the liquefied petroleum gas industry, the main methods of domestic liquefied petroleum gas odorization are mostly based on the odorization method of natural gas. It is mainly carried out by refineries during the tank truck loading process or by adding odorants to the gas station unloading pipeline during the tank truck unloading process. The odorant is mainly tetrahydrothiophene, and the odorization method mainly adopts manual operation.

[0005] The following problems exist in the current liquefied petroleum gas odorization process:

[0006] 1. It is difficult to accurately control the amount of odorant added. During the loading or unloading process of the tank truck, odorization is performed. Since the volatility of tetrahydrothiophene is significantly different from that of liquefied petroleum gas, the amount of odorant added is mainly determined by manual experience. In order to achieve the desired odor effect, the amount of odorant added is often increased based on the theoretical value, making the amount of odorant added difficult to accurately control.

[0007] 2. The actual odorizing concentration in the gas cylinder does not meet the standard. Due to the significant difference in vapor pressure between the odorizer tetrahydrothiophene and liquefied petroleum gas, it easily settles on the bottom of tank trucks and storage tanks, resulting in insufficient odorizing concentration or waste. The lack of odor affects the safety of LPG use.

[0008] 3. Odorants occupy inventory. Odorants accumulate in storage tanks for a long time, occupying already tight inventory capacity and affecting inventory turnover.

[0009] 4. Low level of automation. The odorization process requires a lot of manual operations, making it difficult to accurately control the amount added and the odorization effect cannot be guaranteed. Utility Model Content

[0010] In order to solve the above technical problems, the utility model provides an automatic control device for odorizing liquefied petroleum gas.

[0011] The utility model is realized by adopting the following technical solutions.

[0012] A liquefied petroleum gas (LPG) odorization automatic control device is disclosed. The liquefied petroleum gas is stored in an LPG storage tank, which is connected to an LPG cylinder via an LPG filling pipeline. The odorization automatic control device is provided with a controller, a detection device, and an actuator. The actuator is provided with an odorant output pipeline connected to the LPG filling pipeline. The signal input end of the controller is connected to the output ends of each sensor in the detection device, and the signal output end of the controller is connected to the actuator.

[0013] Furthermore, the actuator includes an odorant storage tank and an odorizing pump, and a control signal of the odorizing pump is input by a controller.

[0014] Furthermore, the detection device includes a flow sensor deployed on the LPG filling pipeline, a micro-flow monitoring sensor deployed on the odorant output pipeline, and a liquid level gauge and a pressure sensor deployed in the odorant storage tank.

[0015] Furthermore, the input end of the odorizing pump is connected to the outlet of the odorizing agent storage tank.

[0016] Furthermore, the odorant output pipeline includes a main pipeline connected to two branch pipelines; the main pipeline is connected to the output end of the odorizing pump, one branch pipeline is connected to the LPG filling pipeline, and the other branch pipeline is connected to the odorant storage tank.

[0017] By using intelligent modules to control the odorization process, compared with the current manual operation during the loading and unloading process, the following benefits are achieved:

[0018] 1. Reduce waste: By adjusting the traditional manual odorization method of tank trucks to automatic and precise control during the filling process, the ineffective deposition and waste of odorant in tank trucks and storage tanks is reduced, and the odorant is able to enter the gas cylinders as much as possible, thus reducing the waste of odorant in the process and the waste of storage tank inventory.

[0019] 2. Ensure the safe use of liquefied petroleum gas: The odorizing amount is accurately controlled through the automation module, so that each bottle of LPG can have a sufficient amount of odorizer. When LPG leakage occurs, users can immediately smell the warning odor and take safety measures, thus fully ensuring the safe use of LPG;

[0020] 3. Improve the level of process automation: By changing traditional manual control to intelligent module control, manual intervention and manual workload are reduced. The control module automatically monitors the odorant tank level, pressure and odorization flow during the odorization process, greatly improving the process safety and controllability and improving the process operation quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a structural diagram of the present utility model.

[0022] Among them, 1. Flow sensor; 2. Controller; 3. Odorant storage tank; 4. Odorizing pump; 5. Micro-flow monitoring sensor; 6. LPG filling pipeline. DETAILED DESCRIPTION

[0023] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0024] like Figure 1 As shown, a liquefied petroleum gas odorization automatic control device is provided. The liquefied petroleum gas is stored in an LPG storage tank, which is connected to an LPG cylinder via an LPG filling pipeline 6. The odorization automatic control device is provided with a controller, a detection device, and an actuator. The actuator is provided with an odorant output pipeline connected to the LPG filling pipeline 6. The signal input end of the controller is connected to the output ends of each sensor in the detection device, and the signal output end of the controller is connected to the actuator.

[0025] There are three controller models to choose from: single-chip microcomputers, industrial computers, and programmable logic controllers (PLCs). Single-chip microcomputers have the simplest functions and are the cheapest; industrial computers and PLCs have more functions and are also more expensive. All three controllers have basic control functions: they can receive gas flow signals and automatically control the output flow of the odorizing pump. They differ in other auxiliary functions. Industrial computers are equipped with a backup controller that can operate independently of the main controller. If the main controller fails, the backup controller automatically operates according to the original parameters. The PLC can control the automatic switching between the four odorizing pumps, and the backup pump automatically operates when the working pump fails. However, single-chip microcomputers and industrial computers can only manually switch the odorizing pump 4 by issuing an alarm signal. In actual applications, the controller should be selected according to actual needs.

[0026] The actuator comprises an odorant tank 3 and an odorant pump 4, whose control signal is input by a controller. Tetrahydrothiophene, the most commonly used odorant, is a flammable and explosive chemical and is not suitable for frequent human contact. Therefore, when selecting the volume of the odorant tank 3, a reasonable refilling cycle should be determined based on the odorant usage; generally, at least one quarter is appropriate. This eliminates the need for frequent odorant refills, ensures safety, and reduces operator workload. The output pressure of the odorant pump 4 is determined based on the operating gas pressure, taking 1.2-1.5 times the gas pressure as the output pressure. The maximum gas flow rate of the odorant pump 4 must be greater than the maximum operating gas flow rate. The odorization accuracy of the odorant pump 4 directly affects the gas odorization accuracy. The importance of odorization accuracy is primarily reflected in the following aspects: a stable odorant concentration is a prerequisite for safe gas supply; full utilization of the odorant reduces gas supply costs; and precise odorant dosage, while providing a warning effect, is environmentally friendly. The odorization accuracy specified in CJJ / T 148-2010 shall not exceed ±5%.

[0027] The detection device includes a flow sensor 1 deployed on the LPG filling pipeline 6 , a micro-flow monitoring sensor 5 deployed on the odorant output pipeline, and a liquid level gauge and a pressure sensor deployed in the odorant storage tank 3 .

[0028] The flow sensor 1 reads the LPG flow rate as a basis for determining the amount of odorant injected.

[0029] The micro flow monitoring sensor 5 is used to monitor the actual flow at the outlet of the odorizing pump 4. If the flow does not meet expectations, the odorizing pump 4 will be adjusted as needed.

[0030] The odorant output pipeline includes a main pipeline connected to two branch pipelines; the main pipeline is connected to the output end of the odorizing pump 4, one branch pipeline is connected to the LPG filling pipeline 6, and the other branch pipeline is connected to the odorant storage tank 3.

[0031] The input end of the odorizing pump 4 is connected to the outlet of the odorizing agent storage tank 3 .

[0032] The working process of the utility model is as follows: a flow sensor 1 provided on the LPG filling pipeline 6 is responsible for real-time monitoring of the flow of the LPG filling pipeline 6, generating a digital signal and feeding it back to the controller 2. The controller 2 analyzes the flow digital signal and calculates the odorization rate corresponding to the odorizer according to the odorizer addition standard. The odorizer addition standard mainly refers to the mass concentration index requirement of the odorizer in CJJ / T 148 "Technical Specification for Odorization of Urban Gas", which is 50mg·m -3(tetrahydrothiophene to liquefied petroleum gas), the controller 2 sends a control signal to the odorizing pump 4, and the odorizing pump 4 adjusts the pump speed according to the control signal to accurately adapt the output flow. The micro-flow monitoring sensor 5 is responsible for monitoring the actual odorizing effect and feeding back the signal to the controller 2 to ensure the implementation effect.

[0033] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the concept and scope of the present invention. Without departing from the design concept of the present invention, various modifications and improvements to the technical solutions of the present invention made by ordinary engineering technicians in this field should fall within the scope of protection of the present invention. The technical contents requested for protection of the present invention have been fully recorded in the technical requirements.

Claims

1. An automatic control device for odorizing liquefied petroleum gas, wherein the liquefied petroleum gas is stored in an LPG storage tank, and the LPG storage tank is connected to an LPG cylinder via an LPG filling pipeline (6); characterized in that The automatic odorization control device is provided with a controller, a detection device, and an actuator; the actuator is provided with an odorant output pipeline connected to an LPG filling pipeline (6); the signal input end of the controller is connected to the output ends of each sensor in the detection device, and the signal output end of the controller is connected to the actuator.

2. The automatic control device for odorizing liquefied petroleum gas according to claim 1, characterized in that: The actuator comprises an odorant storage tank (3) and an odorant pump (4), and a control signal of the odorant pump (4) is input by a controller.

3. The automatic control device for odorizing liquefied petroleum gas according to claim 2, characterized in that: The detection device comprises a flow sensor (1) deployed on an LPG filling pipeline (6), a micro-flow monitoring sensor (5) deployed on an odorant output pipeline, and a liquid level meter and a pressure sensor deployed in an odorant storage tank (3).

4. The automatic control device for odorizing liquefied petroleum gas according to claim 2, characterized in that: The input end of the odorizing pump (4) is connected to the outlet of the odorizing agent storage tank (3).

5. The automatic control device for odorizing liquefied petroleum gas according to claim 1, characterized in that: The odorant output pipeline comprises a main pipeline connected to two branch pipelines; the main pipeline is connected to the output end of the odorant pump (4), one branch pipeline is connected to the LPG filling pipeline (6), and the other branch pipeline is connected to the odorant storage tank (3).

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