Natural gas gate station boiler heating system

Abstract

The utility model discloses a natural gas gate station boiler heating system. The system comprises an in-station pipeline for inputting natural gas, a heat exchanger mounted on the in-station pipeline, and a natural gas pressure regulator connected with the heat exchanger through a pipe body, the outbound pipeline is connected with the natural gas pressure regulator and outputs natural gas; the gas-fired boiler is connected with the heat exchanger and is used for providing high-temperature hot water for the heat exchanger and recycling low-temperature hot water formed after heat exchange of the heat exchanger; gas used by the gas-fired boiler is connected with the outbound pipeline through a gas supply pipeline; the outbound pipeline is provided with a temperature sensor used for detecting the temperature of natural gas in real time when the natural gas is outbound, the temperature sensor is in communication connection with the station control system, and the station control system is further in communication connection with a PLC of the gas-fired boiler so as to be matched with the PLC to control the gas-fired boiler to work, so that the hot gas boiler is automatically controlled, the operation management digital intelligence level is improved, and the working efficiency is improved. The workload of field personnel is reduced, and the probability of manual misoperation is reduced; the gas consumption of the hot-gas boiler is reduced, and the transmission and distribution benefits are improved.

Description

Technical fields:

[0001] This utility model relates to the field of natural gas heating technology, and specifically to a natural gas gate station boiler heating system. Background technology:

[0002] In existing technologies, the incoming gas pressure at natural gas gate stations is relatively high. To meet the gas pressure requirements of downstream customers, the natural gas entering the station needs to be depressurized. However, a significant pressure drop (from 7-8 MPa to 4 MPa) will lower the gas temperature in the pipeline (e.g., below 5°C), causing it to fail to meet safety standards and usage requirements. Therefore, pipeline heating is necessary. Generally, natural gas gate stations use a boiler heat exchanger circulating water system to heat the gas.

[0003] For example Figure 1 The system shown has a heat exchanger 102 installed on the inlet pipe 101. The heat exchanger 102 is located at the front end of the natural gas pressure regulator 103, and the rear end of the natural gas pressure regulator 103 is connected to the outlet pipe 105. The heat exchanger 102 is connected to an indirect gas boiler 104. During operation, natural gas enters the natural gas gate station and flows into the inlet pipe 101, and then enters the heat exchanger 102. At the same time, the gas boiler 104 supplies high-temperature hot water to the heat exchanger 102 to indirectly heat the natural gas passing through the heat exchanger 102, so that the temperature of the natural gas before entering the natural gas pressure regulator 103 is increased, so that the temperature of the natural gas after the pressure regulator 103 is adjusted will not become too low, so that the natural gas entering the outlet pipe 105 will not be blocked by ice due to low temperature, thus meeting the safety standards and usage requirements for leaving the station. The gas boiler 104 is connected to a medium-pressure natural gas pipeline after pressure regulation within the station. It can automatically start and stop based on the outlet water temperature. However, the start and stop temperature settings are manually adjusted by the boiler's built-in PLC controller. The currently used boiler heat exchanger circulating water system (i.e., heating system) has the following problems:

[0004] (1) The temperature of the gas boiler is adjusted manually, which has a low level of automation and is difficult to adjust, which is inconsistent with the user's digital development direction.

[0005] (2) The target control value is the natural gas outlet temperature. However, the gas boiler operates independently using its own PLC controller and is not linked to the natural gas outlet temperature. This results in the inability to effectively control how many degrees Celsius of hot water the gas boiler outputs to the heat exchanger to heat the natural gas before pressure regulation, so that the temperature of the natural gas after pressure regulation meets the safety standards and usage requirements. To achieve this, the gas volume of the gas boiler is usually increased to control the hot water at a higher temperature to the heat exchanger, so that the natural gas before pressure regulation is heated to a higher temperature, so that the temperature of the natural gas after pressure regulation meets the safety standards and usage requirements. Therefore, too much of the gas used for heating water needs to be burned to deliver hot water at a higher temperature to the heat exchanger. This will result in excessive consumption of gas used for heating water, which will lead to waste and higher costs.

[0006] (3) The operation of the gas boiler did not take into account the effects of natural gas inlet temperature, transmission volume and ambient temperature, resulting in serious waste of self-used gas and reduced transmission and distribution efficiency. For example, in summer and winter, two seasons with large temperature differences, the ambient temperature varies greatly. It is necessary to re-estimate or test the required output temperature of hot water from the gas boiler to better heat the natural gas temperature before pressure regulation, so that the natural gas temperature after pressure regulation meets the requirements for leaving the station. This requires constant debugging, which is time-consuming and inefficient, and extremely inconvenient to operate.

[0007] In view of the above, the inventors propose the following technical solution. Utility model content:

[0008] The purpose of this utility model is to overcome the shortcomings of the existing technology and provide a natural gas gate station boiler heating system.

[0009] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: The natural gas gate station boiler heating system includes an inlet pipeline for inputting natural gas, a heat exchanger installed on the inlet pipeline, a natural gas pressure regulator connected to the heat exchanger through a pipe body, an outlet pipeline connected to the natural gas pressure regulator and outputting natural gas, and a gas-fired boiler connected to the heat exchanger and used to provide high-temperature hot water to the heat exchanger and recover low-temperature hot water formed after heat exchange in the heat exchanger. The gas used by the gas-fired boiler is connected to the outlet pipeline through a gas supply pipeline. The outlet pipeline is equipped with a temperature sensor for real-time detection of the temperature of natural gas when it leaves the station. The temperature sensor is communicatively connected to the station control system, and the station control system is also communicatively connected to the PLC controller of the gas-fired boiler itself to cooperate with the PLC controller to control the operation of the gas-fired boiler.

[0010] Furthermore, in the above technical solution, the station control system is also connected to the intelligent operation center, and all data is transmitted to the intelligent operation center. The intelligent operation center can also send control commands to the station control system to control the PLC controller to work.

[0011] Furthermore, in the above technical solution, the intelligent operation center has a SCADA system.

[0012] Furthermore, in the above technical solution, a protective mesh cover is also installed inside the outlet pipe, which covers the outside of the temperature sensor.

[0013] Furthermore, in the above technical solution, the heat exchanger has a first heat exchange channel and a second heat exchange channel that are isolated from each other. The inlet and outlet of the first heat exchange channel are respectively connected to the inlet pipe and the pipe body. The inlet and outlet of the second heat exchange channel are respectively connected to the inlet pipe and the outlet pipe. The inlet pipe is connected to the outlet of the gas boiler, and the outlet pipe is connected to the circulating water return port of the gas boiler.

[0014] Furthermore, in the above technical solution, the water inlet pipe is also equipped with a water pump, a Y-type filter, a first control valve, and a second control valve, with the Y-type filter located at the water inlet end of the water pump.

[0015] Furthermore, in the above technical solution, the heat exchanger is a tubular heat exchanger, which includes a shell and a heating tube that is meandered and arranged inside the shell. The heating tube has a second heat exchange channel formed inside it, and the outer wall of the heating tube and the inner wall of the shell have a first heat exchange channel formed between them.

[0016] Furthermore, in the above technical solution, the heating tube is a corrugated tube with a concave inner wall and a convex outer wall, and the corrugated tube is also provided with a plurality of spaced fins on its exterior.

[0017] Furthermore, in the above technical solution, a third control valve and a fourth control valve are respectively provided at the inlet and outlet of the second heat exchange channel, and the inlet of the second heat exchange channel is also connected to a backwash pipe, which is provided with a fifth control valve, and the outlet of the second heat exchange channel is also connected to a drain pipe for sewage discharge, which is provided with a sixth control valve.

[0018] Furthermore, in the above technical solution, the heat exchanger is a plate-and-shell heat exchanger, which has a shell-side corrugated heat exchange gap serving as the first heat exchange channel and a plate-side corrugated heat exchange gap serving as the first heat exchange channel.

[0019] After adopting the above technical solution, this utility model has the following beneficial effects compared with the prior art: This utility model eliminates the current start-stop interlock setting between the PLC controller built into the gas boiler and the gas boiler outlet water temperature, and modifies it to set the start-stop interlock between the gas boiler's own PLC controller and the outlet natural gas temperature of the outlet pipeline. This realizes bidirectional data transmission between the station control system and the PLC controller, achieving the goal of using the outlet temperature as the target control value. The station control system automatically controls the start and stop of the gas boiler, which can better control the operation of the gas boiler, better control the output temperature of hot water to the heat exchanger, and accurately control the natural gas temperature before pressure regulation. As a result, after the natural gas pressure regulator reduces the pressure, the natural gas temperature is not lower than 5°C, in order to meet safety standards and usage requirements. That is, the gas boiler achieves automatic control, improves the level of digitalization in operation and management, reduces the workload of on-site personnel, and reduces the probability of human error. Specifically, during operation, the temperature sensor inside the outlet pipeline first detects the temperature of the natural gas at the outlet in real time. The station control system collects the temperature detected by the temperature sensor and sends control commands to the PLC controller of the gas boiler. The PLC controller then controls the operation of the gas boiler, enabling it to intelligently burn the input natural gas and accurately output hot water at a reasonable temperature to the heat exchanger. This precisely controls the natural gas temperature before pressure regulation, ensuring that the natural gas temperature is not lower than 5°C after the pressure regulator reduces the pressure. This effectively avoids excessive combustion of natural gas by the gas boiler, thus reducing natural gas consumption, improving transmission and distribution efficiency, and lowering operating costs, achieving the goals of environmental protection and energy conservation. Attached image description:

[0020] Figure 1 This is a structural diagram of a natural gas gate station boiler heating system in the existing technology;

[0021] Figure 2 This is a structural diagram of the present invention;

[0022] Figure 3 This is a partial structural diagram of the heating element in this utility model. Detailed implementation method:

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

[0024] See Figure 2-3The diagram shows a natural gas gate station boiler heating system, comprising an inlet pipe 1 for inputting natural gas, a heat exchanger 2 installed on the inlet pipe 1, a natural gas pressure regulator 4 connected to the heat exchanger 2 via a pipe body 3, an outlet pipe 5 connected to the natural gas pressure regulator 4 and outputting natural gas, and a gas-fired boiler 6 connected to the heat exchanger 2 and used to provide high-temperature hot water to the heat exchanger 2 and recover low-temperature hot water formed after heat exchange in the heat exchanger 2. The gas used by the gas-fired boiler 6 is connected to the outlet pipe 5 via a gas supply pipe. During operation, the input natural gas (pressure typically 7-8) The natural gas (MPa) enters the inlet pipeline 1 and passes through the heat exchanger 2. The natural gas passing through the heat exchanger 2 is indirectly heated by the high-temperature hot water in the heat exchanger 2, which is safe. After being heated by the heat exchanger 2, the natural gas enters the natural gas pressure regulator 4 through the pipe body 3, and the pressure is reduced by the natural gas pressure regulator 4 (the pressure is generally reduced to 4MPa). At the same time, the temperature of the natural gas is reduced during the pressure reduction. Since it is heated by the heat exchanger before pressure regulation, the temperature of the natural gas entering the outlet pipeline 5 is controlled to be no less than 5℃ to meet safety standards and usage requirements.

[0025] This invention mainly makes the following improvements: The outlet pipeline 5 is equipped with a temperature sensor 51 for real-time detection of the natural gas temperature at the outlet. This temperature sensor 51 is communicatively connected to the station control system 7, which is also communicatively connected to the PLC controller 61 of the gas boiler 6 to cooperate in controlling the operation of the gas boiler 6. In other words, this invention removes the current interlocking setting between the gas boiler's built-in PLC controller and the gas boiler's outlet water temperature, and modifies it so that the gas boiler 6's own PLC controller 61 is interlocked with the natural gas outlet temperature of the outlet pipeline 5. This achieves bidirectional data transmission between the station control system 7 and the PLC controller 61, enabling the station control system to automatically control the start and stop of the gas boiler with the outlet temperature as the target control value. This allows for better control of the gas boiler 6's operation, better control of the hot water output to the heat exchanger, and precise control of the natural gas temperature before pressure regulation. Therefore, after the natural gas pressure regulator 4 reduces pressure, the natural gas temperature is not lower than 5°C, meeting safety standards and usage requirements. This achieves automatic control of the gas boiler, improves the level of digital management, reduces the workload of on-site personnel, and lowers the probability of human error. Specifically, during operation, the temperature sensor 51 inside the outlet pipeline 5 first detects the temperature of the natural gas at the outlet in real time. The station control system 7 collects the temperature detected by the temperature sensor 51 and sends control commands to the PLC controller 61 of the gas boiler 6. The PLC controller 61 then controls the operation of the gas boiler 6, enabling it to intelligently burn the input natural gas and accurately output hot water at a suitable temperature to the heat exchanger. This precisely controls the natural gas temperature before pressure regulation, ensuring that the natural gas temperature is not lower than 5°C after the pressure regulator 4 reduces the pressure. This effectively prevents the gas boiler from over-burning natural gas, thus reducing natural gas consumption and improving the efficiency of gas distribution. This invention improves efficiency and reduces operating costs, achieving environmental protection and energy conservation. Furthermore, the operation of the gas boiler in this invention takes into account the influence of natural gas inlet temperature, transmission volume, and ambient temperature. It interlocks the natural gas outlet temperature with the station control system 7 and the gas boiler's PLC controller 61, enabling the gas boiler to operate according to the natural gas outlet temperature. This allows the gas boiler to deliver hot water at a reasonable temperature to the heat exchanger, precisely controlling the natural gas temperature before pressure regulation. After the natural gas pressure regulator 4 reduces the pressure, the natural gas temperature is not lower than 5°C, meeting safety standards and usage requirements. The entire process is automated and requires no constant debugging, is quick and efficient, and extremely convenient to operate.

[0026] The station control system 7 is a conventional system for natural gas gate stations and is also existing technology; it can be a server-like system.

[0027] The station control system 7 is also connected to the intelligent operation center 8, transmitting all data to the intelligent operation center 8. The intelligent operation center 8 can also send control commands to the station control system 7 to control the PLC controller 61. The intelligent operation center has a SCADA system. SCADA systems are existing technology; SCADA (Supervisory Control And Data Acquisition) systems are data acquisition and monitoring control systems widely used in power, metallurgy, chemical, and railway industries. Their main functions include data acquisition, equipment control, measurement, parameter adjustment, and signal alarms, commonly referred to as "four remote" functions. SCADA systems collect data through sensors and actuators and use PLCs and RTUs (Remote Terminal Units) for equipment control. This data is sent to a central computer for processing and management, thereby achieving real-time monitoring and control of industrial processes.

[0028] The outlet pipeline 5 is also equipped with a protective mesh cover 52, which covers the outside of the temperature sensor 51. It can effectively prevent the natural gas in the outlet pipeline 5 from directly impacting the temperature sensor 51, thereby protecting the temperature sensor 51 to a certain extent and enabling the temperature sensor 51 to work normally.

[0029] The heat exchanger 2 has a first heat exchange channel 201 and a second heat exchange channel 202 that are isolated from each other. The inlet and outlet of the first heat exchange channel 201 are respectively connected to the inlet pipe 1 and the pipe body 3. The inlet and outlet of the second heat exchange channel 202 are respectively connected to the inlet pipe 203 and the outlet pipe 204. The inlet pipe 203 is connected to the outlet of the gas boiler 6, and the outlet pipe 204 is connected to the circulating water return port of the gas boiler 6. The inlet pipe 203 is also equipped with a water pump 205, a Y-type filter 206, a first control valve 207, and a second control valve 208. The Y-type filter 206 is located at the inlet end of the water pump 205, and the first control valve 207 and the second control valve 208 are located on both sides of the water pump 205. During normal operation, after the gas boiler outputs hot water, the water pump 205 works to ensure that the hot water can smoothly enter the second heat exchange channel 202 of the heat exchanger. The Y-type filter 206 can play a filtering role, thereby improving the service life of the water pump 205. At the same time, it can reduce the probability of scaling in the heat exchanger, or reduce the scaling cycle, thereby improving the working quality and efficiency of the heat exchanger.

[0030] The heat exchanger 2 is a tubular heat exchanger, which includes a shell 21 and a heating tube 22 that is meandered and arranged inside the shell 21. The heating tube 22 has a second heat exchange channel 202 formed inside it, and the first heat exchange channel 201 is formed between the outer wall of the heating tube 22 and the inner wall of the shell 21.

[0031] The heating tube 22 is a corrugated tube with a concave inner wall and a convex outer wall, which can better achieve the heating effect and at the same time enable the hot water to form turbulence, thus reducing the chance of scaling. In addition, the corrugated tube is provided with a plurality of spaced fins 221 on the outside, which can further improve the heating efficiency.

[0032] The second heat exchange channel 202 is equipped with a third control valve 211 and a fourth control valve 212 at its inlet and outlet, respectively. The inlet of the second heat exchange channel 202 is also connected to a backwash pipe 213, which is equipped with a fifth control valve 214. The outlet of the second heat exchange channel 202 is also connected to a drain pipe 215, which is equipped with a sixth control valve 216. After long-term use, the third and fourth control valves 211 and 212 can be closed, and the sixth control valve 216 can be opened to allow dirt and other contaminants to be drained from the second heat exchange channel 202 through the drain pipe 215. Alternatively, the fifth control valve 214 can be opened, and a high-pressure water pipe can be connected to the backwash pipe 213 to allow high-pressure water to flow into the second heat exchange channel 202, thereby cleaning the second heat exchange channel 202 and ensuring the heat exchange efficiency and quality of the entire heat exchanger.

[0033] The first control valve 207, the second control valve 208, the third control valve 211, the fourth control valve 212, the fifth control valve 214, and the sixth control valve 216 can be ball valves or butterfly valves.

[0034] Alternatively, the heat exchanger 2 is a plate-and-shell heat exchanger, which has a shell-side corrugated heat exchange gap that serves as the first heat exchange channel 201 and a plate-side corrugated heat exchange gap that serves as the first heat exchange channel 201, and can achieve the same heat exchange effect, that is, to heat the natural gas.

[0035] In summary, this utility model eliminates the current interlock setting between the PLC controller built into the gas boiler and the gas boiler outlet water temperature, and modifies it so that the PLC controller 61 of the gas boiler 6 is set to be interlocked with the outlet natural gas temperature of the outlet pipeline 5. This enables bidirectional data transmission between the station control system 7 and the PLC controller 61, achieving automatic control of the gas boiler's start and stop by the station control system with the outlet temperature as the target control value. This allows for better control of the gas boiler 6's operation, better control of the hot water output to the heat exchanger, and precise control of the natural gas temperature before pressure regulation. Consequently, after the natural gas pressure regulator 4 reduces pressure, the natural gas temperature is not lower than 5°C, meeting safety standards and usage requirements. In other words, the gas boiler achieves automatic control, improves the level of digitalization in operation management, reduces the workload of on-site personnel, and lowers the probability of human error. Specifically, during operation, the temperature sensor 51 inside the outlet pipeline 5 first detects the temperature of the natural gas at the outlet in real time. The temperature detected by the temperature sensor 51 is collected by the station control system 7, and a control command is sent to the PLC controller 61 of the gas boiler 6. The PLC controller 61 controls the operation of the gas boiler 6, enabling the gas boiler 6 to intelligently burn the input natural gas and accurately output hot water at a reasonable temperature to the heat exchanger. This accurately controls the temperature of the natural gas before pressure regulation, ensuring that the natural gas temperature is not lower than 5°C after the natural gas pressure regulator 4 reduces the pressure. This effectively avoids the gas boiler from over-burning natural gas, thus reducing natural gas consumption, improving transmission and distribution efficiency, and reducing operating costs, achieving the goal of environmental protection and energy saving. Furthermore, the operation of the gas boiler in this utility model takes into account the influence of natural gas inlet temperature, transmission volume, and ambient temperature. The natural gas outlet temperature is interlocked with the station control system 7 and the PLC controller 61 of the gas boiler, so that the operation of the gas boiler can be controlled according to the natural gas outlet temperature. That is, the gas boiler can be controlled to deliver hot water at a reasonable temperature to the heat exchanger to accurately control the natural gas temperature before pressure regulation. After the natural gas pressure regulator 4 reduces the pressure, the natural gas temperature is not lower than 5°C to meet safety standards and usage requirements. The whole process is automated and does not require constant debugging. It is quick, efficient, and extremely convenient to operate.

[0036] Of course, the above description is only a specific embodiment of the present utility model and is not intended to limit the scope of the present utility model. All equivalent changes or modifications made to the structure, features and principles described in the claims of the present utility model should be included in the scope of the claims of the present utility model.

Claims

1. A natural gas gate station boiler heating system, comprising an inlet pipe (1) for inputting natural gas, a heat exchanger (2) installed on the inlet pipe (1), a natural gas pressure regulator (4) connected to the heat exchanger (2) via a pipe body (3), an outlet pipe (5) connected to the natural gas pressure regulator (4) and outputting natural gas, and a gas boiler (6) connected to the heat exchanger (2) and used to provide high-temperature hot water to the heat exchanger (2) and recover low-temperature hot water formed after heat exchange in the heat exchanger (2), wherein the gas used by the gas boiler (6) is connected to the outlet pipe (5) via a gas supply pipe; Its features are: The outlet pipeline (5) is equipped with a temperature sensor (51) for real-time detection of the temperature of natural gas when it leaves the station. The temperature sensor (51) is connected to the station control system (7). The station control system (7) is also connected to the PLC controller (61) of the gas boiler (6) to cooperate with the PLC controller (61) to control the operation of the gas boiler (6).

2. The natural gas gate station boiler heating system according to claim 1, characterized in that: The station control system (7) is also connected to the intelligent operation center (8) and transmits all data to the intelligent operation center (8). The intelligent operation center (8) can send control commands to the station control system (7) to control the PLC controller (61) to work.

3. The natural gas gate station boiler heating system according to claim 2, characterized in that: The intelligent operation center (8) has a SCADA system.

4. The natural gas gate station boiler heating system according to claim 1, characterized in that: The outlet pipe (5) is also equipped with a protective mesh cover (52), which covers the outside of the temperature sensor (51).

5. The natural gas gate station boiler heating system according to any one of claims 1-4, characterized in that: The heat exchanger (2) has a first heat exchange channel (201) and a second heat exchange channel (202) that are isolated from each other. The inlet and outlet of the first heat exchange channel (201) are respectively connected to the inlet pipe (1) and the pipe body (3). The inlet and outlet of the second heat exchange channel (202) are respectively connected to the inlet pipe (203) and the outlet pipe (204). The inlet pipe (203) is connected to the outlet of the gas boiler (6), and the outlet pipe (204) is connected to the circulating water return port of the gas boiler (6).

6. The natural gas gate station boiler heating system according to claim 5, characterized in that: The inlet pipe (203) is also equipped with a water pump (205), a Y-type filter (206), a first control valve (207) and a second control valve (208), and the Y-type filter (206) is located at the inlet end of the water pump (205).

7. The natural gas gate station boiler heating system according to claim 6, characterized in that: The heat exchanger (2) is a tubular heat exchanger, which includes a shell (21) and a heating tube (22) that is bent and arranged in the shell (21). The heating tube (22) has a second heat exchange channel (202) inside it, and the first heat exchange channel (201) is formed between the outer wall of the heating tube (22) and the inner wall of the shell (21).

8. The natural gas gate station boiler heating system according to claim 7, characterized in that: The heating tube (22) is a corrugated tube with a concave inner wall and a convex outer wall, and the corrugated tube is also provided with a plurality of spaced fins (221) on its exterior.

9. The natural gas gate station boiler heating system according to claim 7, characterized in that: The second heat exchange channel (202) is provided with a third control valve (211) and a fourth control valve (212) at its inlet and outlet, respectively. The inlet of the second heat exchange channel (202) is also connected to a backwash pipe (213), which is provided with a fifth control valve (214). The outlet of the second heat exchange channel (202) is also connected to a drain pipe (215) for sewage discharge, which is provided with a sixth control valve (216).

10. The natural gas gate station boiler heating system according to claim 6, characterized in that: The heat exchanger (2) is a plate-shell heat exchanger, which has a shell-side corrugated heat exchange gap as the first heat exchange channel (201) and a plate-side corrugated heat exchange gap as the first heat exchange channel (201).

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