RU2741168C1 - Stirling engine with controlled output power - Google Patents

Abstract

FIELD: machine building.SUBSTANCE: invention relates to the field of engine building, namely to external combustion heat engines operating on the Stirling cycle on solid, liquid, gaseous fuel or another heat source. Problem, which is solved by the declared invention, consists in improvement of operational, technical, economic and ecological characteristics. Essence of the invention consists in the fact that the Stirling engine with controlled output power includes at least one cylinder containing working gas, displacing and working pistons arranged in the cylinder, which divide its volume into hot and cold cavities, at the same time the working piston is kinematically connected to the actuator through the working piston rod. Cooler, regenerator and heater are installed in series outside cylinder, and power control system includes control device. At that, the engine contains in the heater a low-temperature flameless burner with possibility of heat transfer to the cylinder, and the low-temperature flameless burner itself has a structure with the possibility of providing the combustion process at temperature not higher than 1200 °C. According to the invention, low-temperature flame-free burner is equipped with radiation tube, for example, from silicon nitride, for insulation of surrounding elements of engine structure from heat of combustion products, heat receiver has a structure with the possibility of preliminary heating of incoming gas and air up to 950 °C, and heat exchanger is used as heat exchanger and an exhauster with the possibility of heat transfer from combustion products to process units at oil fields, for example, for heating of crude oil, process water with subsequent emission of combustion products into atmosphere.EFFECT: technical result is higher energy performance, efficiency and environmental friendliness of spent technical products.1 cl, 3 dwg

Description

The invention relates to the field of engine building, in particular to external combustion heat engines operating according to the Sterling cycle on solid, liquid, gaseous fuels or other heat source.

Based on review and analysis of technical literature and IPC patents F02G 1/043, F25B 9/14, F02G 1/05, F02G 5/02, F02G 5/04, F02G 3/00, F01C 1/344, F02G 1/045 , F02B 71/04, H02K 35/02, H02K 7/18, H02K 35/06, F02G 1/055, F02G 1/053, E03B 3/28, B01D 5/00, F04B 35/01, F02F 3/00 , F02F 3/28, F16J 1/00, F02G 1/04, F01B 29/10, F23D 14/18, F01B 23/10, F25B 27/02, as well as patents for the SEC F16J 1/001, analogues were identified:

- RU No. 162044 dated 05/20/2016 according to IPC F02G 1/05;

- RU No. 2135804 from 27.08.1999 according to IPC F02G 1/04, F01B 29/10, F23D 14/18;

- RU No. 191262 dated July 31, 2019 according to IPC F02G 1/043, F02G 1/045, F02G 5/04, H02K 7/18, F01B 23/10;

- RU No. 2440504 from 20.01.2012 according to IPC F02G 1/043, F02G 5/04, F25B 27/02.

As a prototype, a technical solution was adopted based on the utility model "Stirling Engine with Adjustable Output Power" - patent RU No. 162044 dated 20.05.2016 under IPC F02G 1/05.

According to this technical solution, a Stirling engine with an adjustable output power includes at least one cylinder containing a working gas, a displacement and a working pistons placed in the cylinder, dividing its volume into hot and cold cavities, while the working piston is kinematically connected with by an actuator through the working piston rod; a cooler, a regenerator and a heater installed in series outside the cylinder, as well as a power control system containing a control device, a cylinder with a background working gas, and the engine additionally contains a second cylinder with a working gas other than the background gas, a working gas mixture preparation unit, connected to the control device and including a mixing chamber, a compressor, pressure and temperature sensors, a gas relief solenoid valve and connected via a pipeline through an electromagnetic feed valve, a check valve to the engine cylinder, additionally equipped with an excess gas relief valve; as well as to both cylinders of working gases through pipelines through electromagnetic check valves, and also at the same time the engine contains, as an option, a low-temperature flameless burner in the heater with the possibility of transferring heat to the cylinder, and the low-temperature flameless burner itself is designed to ensure the combustion process at a temperature not higher than 1200 ° C, and also at the same time the engine is equipped, firstly, with a heat receiver with the possibility of partial cooling of the combustion products in it and transfer of heat to the incoming gas and air for their preheating, and, secondly, with a heat recovery unit for combustion products.

The features of the known Stirling engine with variable power output, coinciding with the features of the claimed invention, are that the claimed Stirling engine with adjustable power output includes at least one cylinder containing a working gas, a displacement and a working pistons placed in the cylinder dividing its volume into hot and cold cavities, while the working piston is kinematically connected to the actuator through the working piston rod; a cooler, a regenerator and a heater installed in series outside the cylinder, as well as a power control system containing a control device, a cylinder with a background working gas, and the engine additionally contains a second cylinder with a working gas other than the background gas, a working gas mixture preparation unit, connected to the control device and including a mixing chamber, a compressor, pressure and temperature sensors, a gas relief solenoid valve and connected via a pipeline through an electromagnetic feed valve, a check valve to the engine cylinder, additionally equipped with an excess gas relief valve; as well as to both cylinders of working gases through pipelines through electromagnetic check valves, and also at the same time the engine contains, as an option, a low-temperature flameless burner in the heater with the possibility of transferring heat to the cylinder, and the low-temperature flameless burner itself is designed to ensure the combustion process at a temperature not higher than 1200 ° C, and also at the same time the engine is equipped, firstly, with a heat receiver with the possibility of partial cooling of the combustion products in it and transfer of heat to the incoming gas and air for their preheating, and, secondly, with a heat recovery unit for combustion products.

The reason that prevents the known technical solution from obtaining the technical result, which is provided by the claimed invention, is that the technical means of the known Stirling engine with adjustable output power do not allow to ensure its high operational, technical, economic and environmental characteristics.

The problem to be solved by the claimed invention is to improve the operational, technical, economic and environmental characteristics.

The technical result, which ensures the solution of this problem, consists in the creation of technical means that make it possible to improve the operational, technical, economic and environmental characteristics of a Stirling engine with a controlled output power, namely, energy efficiency, efficiency and environmental friendliness of spent technical products emitted into the atmosphere.

The technical result is achieved by the fact that in the inventive Stirling engine with adjustable output power, which includes at least one cylinder containing a working gas, a displacement and working pistons placed in the cylinder, dividing its volume into hot and cold cavities, while the working piston is kinematically connected to the actuator through the working piston rod; a cooler, a regenerator and a heater installed in series outside the cylinder, as well as a power control system containing a control device, a cylinder with a background working gas, and the engine additionally contains a second cylinder with a working gas other than the background gas, a working gas mixture preparation unit, connected to the control device and including a mixing chamber, a compressor, pressure and temperature sensors, a gas relief solenoid valve and connected via a pipeline through an electromagnetic feed valve, a check valve to the engine cylinder, additionally equipped with an excess gas relief valve; as well as to both cylinders of working gases through pipelines through electromagnetic check valves, and also at the same time the engine contains, as an option, a low-temperature flameless burner in the heater with the possibility of transferring heat to the cylinder, and the low-temperature flameless burner itself is designed to ensure the combustion process at a temperature not higher than 1200 ° C, and also at the same time, the engine is equipped, firstly, with a heat receiver with the possibility of partial cooling of the combustion products in it and transfer of heat to the incoming gas and air for their preheating, and, secondly, with a heat exchanger for combustion products, and This low-temperature flameless burner is equipped with a radiant tube, for example, made of silicon nitride, to isolate the surrounding engine structural elements from the heat of combustion products, the heat receiver has a design with the ability to preheat the incoming gas and air up to 950 ° C, and heat is used as a heat exchanger exchangers and a smoke exhauster with the ability to transfer heat from combustion products to technological units in oil fields, for example, for heating crude oil, process water with the subsequent release of combustion products into the atmosphere.

The technical result is also achieved by the fact that the heat exchangers and the smoke exhauster are designed with the possibility of ejecting combustion products into the atmosphere at a temperature not exceeding 50 ° C.

The above-described created technical means as part of the inventive Stirling engine with adjustable output power make it possible to do the following.

Firstly, the created technical means make it possible to improve the operational and technical characteristics of the Stirling engine with a controlled output power, namely, to increase the energy efficiency of the engine's working process by achieving high combustion efficiency (gas + air) and maximum use of the thermal energy generated in the engine at the movement of combustion products along the entire thermal path of the engine until they are released into the atmosphere. The foregoing is ensured by the fact that the Stirling engine contains a low-temperature flameless burner in the heater with the possibility of transferring heat to the cylinder, and also by the fact that the low-temperature flameless burner has a design and a combustion process control unit with the ability to ensure the combustion process at a given temperature range, in particular at 1050 -1200 ° C.

And the maximum use of the thermal energy generated in the engine during the movement of combustion products along the entire thermal path of the engine up to their emission into the atmosphere is ensured by the fact that the Stirling engine is equipped with a heat receiver with the possibility of partial cooling of combustion products in it and transfer of heat to the incoming fuel components (gas and air ) to preheat them to an optimum temperature of 950 ° C, as well as the fact that the Stirling engine with adjustable output power is equipped with a heat exchanger for the combustion products (gas + air), which are used, in particular, heat exchangers and a smoke exhauster with the possibility of transferring heat from combustion products to technological units in oil fields (for example, for heating crude oil, process water, etc.) with the subsequent release of combustion products into the atmosphere at a minimum temperature (not higher than 50 ° C).

Secondly, the created technical means make it possible to improve the economic characteristics of a Stirling engine with a variable output power, namely, the economic characteristics of a Stirling engine with a variable output power, which consists in increasing the efficiency (efficiency) of the entire engine due to the presence of a combustion control unit with the possibility ensuring the combustion process at specified parameters (flow rate, temperature, organization of the movement of the initial fuel components and their combustion products) and heat and mass transfer processes.

Thirdly, the created technical means make it possible to improve the environmental characteristics of the Stirling engine with adjustable output power, which consists in ensuring the environmental friendliness of the spent technical products emitted into the atmosphere due to the fact that the low-temperature flameless burner has a design with the ability to ensure the combustion process at a temperature not higher than 1200 ° C ... It has been shown by theory and experiments that at this temperature (and not higher) the percentage of harmful substances in the combustion products is minimal, and at higher temperatures this percentage increases sharply. The combustion process control unit as part of a low-temperature flameless burner ensures the combustion process at an optimal temperature in the range of 1050-1200 ° C, at which both the combustion process is stable and the percentage of harmful substances emitted into the atmosphere is minimal. At the same time, the low-temperature flameless burner is equipped with a radiant tube, for example, made of silicon nitride, to isolate the surrounding engine elements from the heat of combustion products, which also reduces the total flow of thermal emissions into the atmosphere and contributes to an increase in the service life of a Stirling engine with a controlled output power, which is part of operational and technical characteristics of the engine.

New features of the proposed technical solution are that the Stirling engine with adjustable output power contains as an option a low-temperature flameless burner equipped with a radiation tube, for example, silicon nitride, to isolate the surrounding engine elements from the heat of combustion products, with the possibility of transferring heat to the cylinder, the heat receiver has a design with the ability to preheat the incoming gas and air up to 950 ° C, and heat exchangers and a smoke exhauster are used as a heat exchanger with the possibility of transferring heat from combustion products to technological units in oil fields, for example, for heating crude oil, process water with the subsequent release of combustion products into the atmosphere.

At the same time, in a Stirling engine with an adjustable output power, the heat exchangers and the smoke exhauster are designed with the possibility of exhausting combustion products into the atmosphere at a temperature not higher than 50 ° C.

The invention is illustrated in the drawings (Fig. 1 - Fig. 3), which shows a Stirling engine with variable output power and a justification of some of its characteristics.

FIG. 1 is a block diagram of a Stirling engine with adjustable power output with a low temperature flameless burner included in it.

FIG. 2 - a fragment (part) of a Stirling engine with an adjustable output power, namely, a low-temperature flameless burner with devices for supplying fuel components to it and with devices for removing combustion products from it until they are released into the atmosphere.

FIG. 3 is a graph of the dependence of the formation of emissions of toxic substances on the combustion temperature of the fuel (gas + air).

The Stirling engine (Fig. 1) contains a cylinder 1, in which the displacement 2 and the working 3 pistons are installed, dividing the volume of the cylinder 1 into hot and cold cavities, while the working piston 3 is kinematically connected to the actuator 4 through the working piston rod 5. On the outer the surface of the cylinder 1 contains a heater 6 and a cooler 7, between which a regenerator 8 is installed, while the cylinder 1 is filled with a working gas 9 supplied through a pipeline through a check valve 10 and an electromagnetic feed valve 11 from a working gas mixture preparation unit 12, including a mixing chamber, a compressor , pressure and temperature sensors. The unit is connected to the cylinders of background and additional one-component working gases 13 through electromagnetic check valves 14, controlled by the control device 15. In addition, the engine cylinder 1 and the gas mixture preparation unit contain electromagnetic check valves for dumping excess gas 16 and 17, respectively. A Stirling engine with adjustable power output contains a low-temperature flameless burner 18 as part of a heater 6 with the ability to transfer heat to a cylinder 1. A low-temperature flameless burner 18 is equipped with a radiation tube 24, for example, of silicon nitride, to isolate the surrounding engine elements from the heat of combustion products.

The basic principle of the Stirling cycle is the periodic heating and cooling of the working fluid in the engine cylinder, with the extraction of energy from the resulting change in the volume of the working fluid.

The claimed invention uses a device that changes the composition of the working fluid during the operation of the engine. A two-component gas is used as a working fluid, which is a mixture of two gases with different thermodynamic properties, for example, helium and nitrogen. Since the thermal conductivity of helium is much higher than nitrogen, its use as a working fluid will cause a higher frequency of piston movement than when using nitrogen. Thus, by varying their percentage by mass, during operation it becomes possible to adjust the output mechanical characteristics of the engine at the maximum thermodynamic efficiency of the engine.

The device works as follows.

When starting the engine, cylinder 1 is filled with a single-component background gas having the required operating pressure. In this case, the engine operates according to the Stirling cycle, ensuring the generation of the corresponding rated output power on the actuator 4.

If it is necessary to change the engine output power, an external control command is sent to the control device 15 in the form of a digital coded signal about setting the required engine output power. The controller of the control device 15, according to an internal algorithm, calculates the required ratio of gas concentrations, taking into account the subsequent mixing with the background gas in the engine cylinder, and transmits the task to the gas mixture preparation unit 12. The mixing chamber of the gas mixture preparation unit 12 is supplied through the electromagnetic check valves 14 a dosed amount of one-component gases from cylinders 13 required to ensure a given operating mode. The gas parameters inside the mixing chamber are monitored by pressure and temperature sensors. The check valve 17 as part of the gas mixture preparation unit 12 provides an emergency release of pressure in case of exceeding the maximum safe operating level.

After gas preparation in block 12, a prepared mixture of gases is supplied to cylinder 1 through the solenoid feed valve 11 and check valve 10, while the excess background gas is discharged through the solenoid valve 16. minimal.

In connection with a change in the thermodynamic properties of the working fluid, there is a natural change in the rate of compression and expansion of the working fluid in the Stirling cycle, all other conditions being equal (temperatures of heater 6, cooler 7 and their design), thereby changing the frequency of movement of the working piston, which leads to changes in engine power output.

A low-temperature flameless burner with devices for supplying fuel components to it and with devices for removing combustion products from it until they are released into the atmosphere (Fig. 2) consists of a working chamber 19 and a control unit 20 for burner operation. A gas supply pipeline 21 (APG or NG or the like) and an air supply pipeline 22 are connected to the control unit 20. From the burner, a pipeline for the removal of combustion products 23 is diverted. The burner is equipped with a radiant tube 24, for example, made of silicon nitride, which covers the working chamber 19 of the burner in such a way as to shield (protect) the surrounding elements of the engine structure from the heat of combustion products, and also to exclude ( reduce) heat loss of the burner working process.

The gas in the pipeline 21 and the air in the pipeline 22 are heated by the products of fuel combustion by placing a heat receiver 25 at the inlet sections of these pipelines 21 and 22. The combustion products enter the heat receiver 25 from the outlet of the working chamber 19 of the burner.

The combustion products from the heat receiver 25 enter the heat exchanger 26 and then through the smoke exhauster 27 are discharged into the environment. Heat exchanger 26 heats process products (eg crude oil and / or process water, etc.) typically found in oilfield processes. For this, the heat exchanger has pipelines 28, 29, 30, 31 for the supply and discharge of the named technological products.

The dependence of the formation of emissions of toxic substances (their content in combustion products) on the combustion temperature of the fuel (gas + air) are shown in the graph (Fig. 3). The graph confirms the minimization of NOx and CO emissions into the environment due to the combustion process on a flameless burner at a temperature not exceeding 1200 ° C compared to the open flame process ("Report under contract No. 4-NIR-12519/11" Research, experimental design work on the creation of an experimental technology for the utilization of associated petroleum gas with the receipt of electrical and thermal energy "Stage 1" Search and assessment of existing technological and technical solutions. Review of completed systems. Justification of the selected technical solution "", Scientific and technical report of PJSC, "Proton- PM ", Perm, 2011, p. - 41).

The low-temperature flameless burner makes it possible to solve the issue of reducing the formation of active sulfur-containing compounds due to the formation of passive oxides, including SO _3, and thereby extend the service life of equipment when burning sulfur-containing fuels, including associated petroleum gas (APG). This burner also allows:

- significantly reduce fuel consumption due to deep recovery of the heat of combustion products with its transfer to the fuel and air supplied to the burner;

- to ensure the maintenance of the specified adiabatic temperature of fuel combustion;

- to minimize the emission of NOx and CO into the environment by carrying out the combustion process on a flameless burner at an adiabatic temperature not exceeding 1200 ° C.

Based on the above, it follows that the technical solution, which is the subject of the claimed invention "Stirling engine with adjustable output power", provides a solution to the problem of the invention - improving the operational, technical, economic and environmental characteristics by obtaining a technical result, namely, creating technical means , allowing to improve the named characteristics of the engine, consisting in increasing energy efficiency, efficiency and environmental friendliness of the spent technical products emitted into the atmosphere.

Claims (2)

1. Stirling engine with adjustable output power, including at least one cylinder containing the working gas, the displacement and working pistons placed in the cylinder, dividing its volume into hot and cold cavities, while the working piston is kinematically connected to the actuator through working piston rod; a cooler, a regenerator and a heater installed in series outside the cylinder, as well as a power control system containing a control device, a cylinder with a background working gas, while the engine additionally contains a second cylinder with a working gas other than the background gas, a working gas mixture preparation unit connected to the control device and includes a mixing chamber, a compressor, pressure and temperature sensors, a gas relief solenoid valve and connected via a pipeline through a solenoid feed valve, a check valve to the engine cylinder, additionally equipped with an excess gas relief valve, as well as to both working gas cylinders through pipelines through electromagnetic check valves, while the engine contains a low-temperature flameless burner as part of the heater with the ability to transfer heat to the cylinder, and the low-temperature flameless burner itself is designed to ensure the combustion process at a rate temperature not higher than 1200 ° C, while the engine is equipped with a heat receiver with the possibility of partial cooling of combustion products in it and heat transfer to the incoming gas and air for their preheating, as well as a heat recovery unit for combustion products, characterized in that the low-temperature flameless burner is equipped with a radiation tube , for example, silicon nitride, to isolate the surrounding engine structure from the heat of combustion products, the heat receiver has a design with the ability to preheat the incoming gas and air up to 950 ° C, and heat exchangers and a smoke exhauster are used as a heat exchanger with the ability to transfer heat from the products combustion to technological units in oil fields, for example, for heating crude oil, process water with the subsequent release of combustion products into the atmosphere. 2. A Stirling engine with an adjustable output power according to claim 1, characterized in that the heat exchangers and the smoke exhauster are designed to discharge combustion products into the atmosphere at a temperature not exceeding 50 ° C.

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