Temperature control and flame monitoring system for a city gas heater with tank water circulation and use of the heater chimney exhaust heat

Abstract

Temperature control and flame monitoring system of the city gas heater with tank water circulation and use of the heater chimney exhaust heat, \n In the city gas pressure reduction stations CGS and CGS\u0026TBS, due to the gas pressure reduction process and according to the gas fluid law, the gas temperature decreases in proportion to its pressure drop. This temperature decrease leads to problems such as freezing of equipment and formation of hydrate in city gas lines. To solve these problems, before performing the pressure reduction process, the gas is preheated by gas heater equipment. This equipment is indirect and in a water bath. The heater heats the gas in the network. Considering the installation location in a dangerous area, the correct operation and safety of the equipment are very important. In this invention, a system has been designed that uses an intelligent PLC controller, actuators, and modern sensors, and eliminates old mechanical equipment to monitor and control the flame and temperature of the heater equipment accurately and intelligently. Also, by adding a water circulation system in the heater tank and using the heat lost in the heater chimney and controlling the temperature of the station's gas outlet network, the correct operation, safety, and optimization of the equipment are achieved.

Description

Description of the invention Title of the invention Temperature control and flame monitoring system for city gas heating devices with tank water circulation and use of exhaust heat from the heater chimney of CGS / CGS&TBS stations Technical background of the relevant invention In gas pressure reduction stations, at the time and place of reducing gas pressure in regulators, the temperature of the gas fluid also decreases in the same proportion, which leads to problems such as freezing in equipment and also the formation of hydrate in urban gas lines. In order to prevent these problems, the gas is preheated by gas heater equipment first and before performing the pressure reduction process. This process is performed by gas heater equipment. The technical field of the invention is related to intelligent and optimal control of the operation of gas heater equipment in urban gas pressure reduction stations. Technical problem and stating the objectives of the invention In CGS & CGSTBS gas pressure reduction stations, according to the pressure reduction process, at the time and place of gas pressure reduction in the regulators, based on the gas laws P1.V1 / T1=P2.V2 / T2 Boyle's law and the relationship between pressure, temperature and volume, the temperature of the gas fluid also decreases in the same proportion. This temperature reduction sometimes leads to problems such as freezing in the equipment (due to the small amount of water present in the natural gas composition) and also the formation of hydrates in the city gas lines. In order to prevent these problems, first and before performing the gas pressure reduction process, the city gas is preheated by equipping with gas heaters and then the pressure reduction operation is performed, so that the effect of the temperature drop in the regulator and the pressure drop location is reduced. The gas heater is equipped indirectly and the hot water bath heats the gas inside the pipe and network with an atmospheric burner. Therefore, considering the installation location in the station's danger zone and the importance of safety and correct operation of the equipment, precise control and monitoring of the flame and temperature in the heater must be carried out. The existing systems, due to their old age and the use of mechanical equipment, have problems and a high failure rate, including technical problems in the existing systems: -Using control equipment and sensors with old mechanisms such as T-valves and thermocouples with low accuracy and a high failure rate, - Waste of energy due to the lack of precise flame control and mechanisms of existing old systems, - Energy waste due to the lack of uniform distribution of thermal energy and improper temperature transfer in the distilled water intermediate fluid in the heater tank, Based on the above explanations, the goal of this project can be stated in three parts to solve existing problems as follows: A - The first goal of the project is to precisely control the flame stability and temperature control in these heaters, in which in this project, monitoring and control operations of the equipment are carried out using controllers, actuators, sensors and state-of-the-art equipment (in existing systems, this is done with low accuracy). B- The second goal of the design is to achieve uniform distribution of thermal energy and proper temperature transfer in the water medium inside the heater tank, by adding a water circulation system to this equipment to increase the efficiency of the system (not done in existing systems). C- The third goal of the plan is to use the waste heat in the output chimney of this equipment to prevent energy waste and increase efficiency (not done in existing systems). A description of the state of the prior art and the history of developments related to the claimed invention. Currently, gas heater equipment is monitored and controlled in various ways. These old methods were very useful and important at the time of design, but due to technological advances and the emergence of new equipment, as well as the importance of saving energy, these systems have lost their place. The main problems with these systems are the excessive consumption of energy carriers and the use of equipment with simple and manual functions such as T-valves, thermocouples, and physical sensors. In the designed system, the control and monitoring of heaters, energy consumption, and performance accuracy are very important, and sensors and smart controllers have been used. In the aforementioned equipment, efforts have been made to improve the efficiency of the equipment and ensure optimal use of energy carriers by increasing the accuracy of the equipment's performance (using appropriate sensors, actuators, and controllers) and by adding new mechanisms such as a tank water circulation system and heating it with heat lost in the chimney. A search was conducted on the mentioned sites regarding the mentioned project, but no topic close to this project was found, including: 1. http: / / ipm.ssaa.ir / Search-Invention 2. http: / / patentscope.wipo HYPERLINK "http: / / patentscope.wipo.int / search / en / structuredSearch.jsf". HYPERLINK "http: / / patentscope.wipo.int / search / en / structuredSearch.jsf" int / search / en HYPERLINK "http: / / patentscope.wipo.int / search / en / structuredSearch.jsf" / HYPERLINK "http: / / patentscope.wipo.int / search / en / structuredSearch.jsf" structuredSearch.jsf 3. https: / / worldwide.espacenet.com / beta 4. http: / / www.uspto.gov HYPERLINK "http: / / www.uspto.gov / patents / process / search / index.jsp" / HYPERLINK "http: / / www.uspto.gov / patents / process / search / index.jsp" patents / process / search / index HYPERLINK "http: / / www.uspto.gov / patents / process / search / index.jsp" . HYPERLINK "http: / / www.uspto.gov / patents / process / search / index.jsp" jsp 5. https: / / patents.google.com 6. http: / / www.freepatentsonline.com / search.html 7. https: / / www.lens.org / lens / Most of the cases were related to home water heaters and car heating systems, which were not proportionate to the topic of the proposed project. Providing a solution to the existing technical problem along with an accurate, sufficient and integrated description of the invention. Considering the above and in order to solve the problems mentioned, the performance of the equipment can be introduced and examined in three sections: The first step is to review and introduce how to set up and control the performance of the equipment. The second step is to review and introduce the performance of the water circulation system and improve the efficiency of the equipment. Step three: Review and introduce the system performance control mechanism by monitoring the outlet network gas temperature. The above items are described in detail below. Part One: Review and introduction of how to set up and control the performance of the equipment The fuel (gas) required by the heater is supplied from the outlet network of the Down Stream station and after passing through the water heater tank, it is first filtered by the gas filter 6 and the impurities in it are removed. Then, with the pressure reducing equipment of the regulator 10 and the safety valve 9, the safety valve 12, the required pressure of the fuel of the heater burner is supplied and the gas pressure is reduced to about 20 psi. The gas pressure required by the pilot or spark plug 21 is supplied and lit by the regulator number 13 by controlling the solenoid valve SOV number 17 and valve 19. In this way, the igniter 23 operates with the intelligent relay PLC and the solenoid valve 17 is opened and the spark plug remains lit for 5 seconds. If the flame detection sensor 20 detects the flame, the process continues, otherwise the solenoid valve 17 cuts off the gas and after a few minutes the process is repeated again. This operation is repeated up to five times. If the system does not function properly, the system process is interrupted and an alarm is activated so that the operator can fix the system problem. If the small Pilot 21 burner is operating properly, the system will first light up. After the small burner is lit, the Pilot 21 must meet the conditions for the large Berner 22 burner to light up so that the large burner can also light up. The first condition: If the flame detection sensor 20 detects the flame, the PLC controller issues a command to open the solenoid valve 16 after a few seconds to open the gas path of the control valve 15. The second condition is the water and gas temperature. If the gas and water temperatures controlled by the temperature controllers including the gas temperature controller 1, the water temperature controller 2, and the gas temperature of the outlet network Down Stream Temperature controlled by the sensor 26 are within the defined range, the gas instrumentation signal (3 to 15 psi) from the regulator number 11 reaches the control valve number 14 and the control valve opens the path (Explanation: If the temperature of the tank water or the outlet gas is higher than the defined range, the signal path to the control valve number 14 is cut off and the control valve remains closed and the large burner does not light up). In the event of Establishing these two control conditions opens the gas path for the large Berner burner, and the large burner is also lit andUntil the gas or water temperature reaches the desired range and when the water or gas temperature or both are heated again, the instrument signal path is interrupted by devices 1 and 2. Control valve 14 interrupts the burner gas path and the large burner gradually turns off. This cycle is repeated regularly with a gentle temperature change (according to the above description and according to the air temperature conditions and the amount of gas consumption, the time interval for turning on and off the large burner changes, but the pilot light is always on). It should be noted that if the water level in the tank, which is controlled by sensor number 25, falls below a certain level, the PLC controller, after receiving the data, issues a command to shut off the gas to the large burner through solenoid valve 16. In general, the requirement for the large burner to turn on is that the water and gas temperatures are low, the water level in the tank is sufficient, and the small burner is on. Also, at any stage of the heater's operation and for any reason, if the flame goes out and the flame detection sensor 20 does not detect the flame, in order to ensure the safety of the system and prevent gas from being released into the equipment, the PLC controller issues a command to completely cut off the gas to the large burner 22 and the small candle burner 21 by means of solenoid valves 16 and 17, and the system goes into safe mode. After a few minutes (the environment is safe from the released gas), the start process is repeated and the heater burners are turned on again. If they do not turn on, it operates in the same way up to five times. If the heater burners do not turn on after five repetitions, it is clear that there is a problem in the system, as a result, the system is shut down and an alarm is activated so that the operator can take care of it and make the necessary repairs. By establishing all the conditions and performing the above steps, the heater burners will be turned on. Part Two: Review and introduction of the performance of the water circulation system, improving equipment efficiency One of the innovations of this system is the addition of a water circulation system in the heater tank, in such a way that the temperature of the intermediate fluid (distilled water) is measured by the temperature sensor 24 and its data is sent to the PLC controller. When this temperature falls below the defined range, the PLC controller issues a command to turn on the pump 4. In this way, the intermediate fluid (distilled water) is pumped by the pump 4 from the bottom of the tank after passing through the heater's Exhaust chimney 30 and heating to the top of the tank. This operation is performed in a repetitive cycle with the command of the PLC controller when the large burner is on (provided that it is on). In this way, firstly, the heat and energy wasted in the chimney are used to heat the tank water, and secondly, by creating circulation in the tank water, the speed of heat distribution in the water increases, which leads to better efficiency in the equipment. Part Three: Review and introduction of the system performance control mechanism by monitoring the outlet network gas temperature. Another innovation of this system is that by using an electrical temperature sensor installed on the station's outlet gas network (Sensor 26 Down Stream Temperature) and converting and sending the output temperature data to the PLC controller, the large burner's on and off interval can be adjusted according to the station's outlet gas network temperature. This prevents the large heater burner from turning on at times when the gas consumption and flow rate through the station are low and the gas outlet temperature (after the regulator and pressure reduction process) does not drop and there is no need to preheat the gas. It should be explained that the temperature control sensors (tank water temperature control, heater outlet gas temperature control, and station outlet gas temperature control) are in series in the circuit, and whichever reaches the defined temperature range first causes the large burner to shut down. Explanation of shapes, maps and diagrams Explanation of the shapes and introduction of the design equipment according to the attached map: 1-Gas temperature controller 2- Water temperature controller 3- Tank water outlet valve 4- Water tank circulation pump 5 – Heater fuel gas inlet valve 6- Heater fuel gas filter 7- Heater fuel gas filter drain valve 8- Valve after heater fuel gas filter 9- Shut off valve for fuel line gas flow 10 Gas Regulator 11- Precision Instrument Pressure Reducing Regulator Gas Regulator 12- Fuel line gas safety valve 13- Gas Regulator: Small burner fuel gas pressure reducing regulator (pilot or spark plug) 14- Temperature control valve 15 – Flame control valve 16- Berner Solenoid valve for large burner control #x200f17 #x200f#x200f–#x200f#x200f solenoid valve #x200f#x200fsmall torch (pilot candle)#x200fPilot Solenoid valve 18- Large burner control valve 19- Small burner control valve (pilot) 20- Flame detector 21- Small torch (pilot) 22- Berner Large Torch 23- Arce ceramic spark plug 24-Low level control 25 – High water level control 26- Electric temperature sensor Sensor 27-Electrical control box Control box 28- Gas input to the heater Input GAS 29- Gas output from heater Output GAS 30- Exhaust heater chimney A clear and precise statement of the advantages of the claimed invention over prior inventions. Among the advantages of the designed equipment compared to previous models: -Using electrical components, smart relays, and modern equipment to automatically and accurately control heater performance (previous systems used old equipment). -Adding a water circulation system mechanism to the heater tank to evenly distribute heat and increase the efficiency of the equipment (this mechanism does not exist in previous systems). -Reuse of the heat lost in the heater chimney to heat the tank water temperature (this mechanism does not exist in previous systems). -Automatic control of all the above steps by a smart relay controller (programmed by the designer) and a combination of electrical and mechanical components to control the equipment. Description of at least one implementation method for implementing the invention This equipment is used in the flame and water temperature control and monitoring system of water heaters, heaters, and boilers, and can usually be used in systems that require heating water in a tank, for example, in the engine room of residential and commercial complexes and in the water heating system of swimming pools. Explicit mention of the industrial application of the invention As mentioned in the above description, this equipment is specifically used in the gas industry and in city gas pressure reduction stations (CGS, CGS&TBS) to preheat the gas before the pressure reduction process and to prevent the phenomenon of freezing and gas hydration in equipment, as well as in residential, commercial and industrial heaters.

Claims

Claim What is claimed: Claim 1) It is claimed that the temperature control and flame monitoring system of a city gas heater with tank water circulation and use of the heater chimney outlet heat is a system and process for controlling and monitoring the heater flame, controlling and monitoring the heater water temperature, controlling and monitoring the gas temperature, along with the heater tank water circulation mechanism and reusing the heat lost in the heater chimney outlet, which is automatically performed and controlled by a smart relay, electrical equipment and mechanical equipment. Claim 2) According to claim number 1, in this system, the process of controlling and monitoring the heater flame, controlling the water and gas temperatures inside the heater is carried out intelligently and automatically by the Mini PLC smart relay, with information received from temperature and water level sensors and electrical and mechanical equipment. Claim 3) According to claim number 1 and claim number 2, in this system, the process of controlling the water temperature of the heater tank is carried out by turning on and off the large heater burner by the Mini PLC smart relay. Claim 4) According to claim number 1, in this system, the water circulation process is carried out using an electric pump in order to quickly and uniformly transfer the water temperature inside the tank and better transfer the temperature to the gas network inside the heater. Claim 5) According to claim number 1 and claim number 3, in this system, circulating water passes through the heater chimney and is reheated using the wasted temperature of the heater chimney and added to the water in the tank. Claim 6) According to claim number 1, in this system, in addition to controlling and monitoring the temperature of water and gas inside the heater, the process of controlling and monitoring the temperature of the gas network exiting the station is carried out by an electrical sensor. Claim 7) According to claim number 1 and claim number 5, in this system, the temperature of the station's outlet gas network is measured by an electrical sensor, and this data is sent to the Mini PLC smart relay for automatic control of turning on and off the large burner, so that the system is controlled intelligently and automatically with high safety.

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