Stirling engine device based on ammonia phase change heat exchange technology

Abstract

The invention discloses a Stirling engine device based on an ammonia phase change heat exchange technology, which belongs to the field of ammonia energy power and comprises a liquid ammonia supply module, an ammonia vaporizer, an ammonia gas ejector, a pure water supply module, an ammonia-water mixing heat exchanger, a Stirling engine, an ammonia water recovery module and a control system. The Stirling engine is composed of an expansion cavity, a heater, a heat regenerator, a cooler and a compression cavity, power is output through working medium cooling, compression, heat absorption and expansion circulation, liquid ammonia in the ammonia vaporizer is vaporized and absorbs heat in a phase change mode to provide cooling capacity for the cooler, ammonia gas in the ammonia-water mixing heat exchanger is dissolved in water to release dissolution heat to supply heat for the heater, and non-combustion energy supply is achieved. The ammonia gas ejector dynamically adjusts the injection amount to meet the thermal load requirement, and the control system cooperatively controls the supply amount and pressure of liquid ammonia / pure water and the power of the engine. The whole machine utilizes the synergistic effect of ammonia vaporization latent heat and dissolution heat, no tail gas pollutant is discharged, an ammonia water mixture can be recycled, and the zero-carbon power requirement is met.

Description

Technical Field

[0001] The present invention relates to the field of ammonia energy power, and particularly to a Stirling engine device based on ammonia phase change heat transfer technology, which is used to develop a zero-carbon emission ammonia energy Stirling engine. Background Art

[0002] Energy crisis and environmental pollution are important issues faced by the survival and development of human society. The global energy system dominated by fossil fuels has led to an increasing amount of CO 2 emissions, resulting in problems such as global climate change. Finding low-carbon and clean new fuels has become an important way for sustainable development in the energy field.

[0003] Hydrogen and ammonia are two carbon-free fuels that do not produce CO 2 during combustion, and they are new fuels with great development prospects for replacing fossil fuels and reducing carbon emissions. Hydrogen energy has long been regarded as the most ideal clean energy and is the focus of research in the energy development strategies of many countries. At present, the development of hydrogen energy still faces key problems such as poor safety and immature storage and transportation technologies. Ammonia has advantages such as high energy density, easy liquefaction for storage and transportation, and high safety; green ammonia can be prepared and synthesized from renewable energy sources such as solar energy, wind energy, and hydropower, and can be used as an important energy storage medium. Therefore, considering economy, safety, carbon neutrality, etc., ammonia as a fuel has a bright future. However, using ammonia as an engine fuel still faces many challenges. Ammonia combustion has problems such as difficult ignition, low laminar flame speed, and narrow flammable range. Moreover, during the combustion of hydrogen and ammonia, toxic NO x is produced, and when ammonia combustion is incomplete, unburned ammonia and NO x and other pollutant tail gas emissions are generated. By utilizing the cold energy generated by the vaporization phase change endothermic of liquid ammonia and the dissolution heat released when ammonia dissolves in water, there is no need to burn ammonia during the energy utilization process, so there is no problem of tail gas pollutant emissions. The ammonia-water mixture generated during the working process can be recycled for scenarios such as fertilizers, and truly zero-carbon and no combustion tail gas pollutant emissions can be achieved.

[0004] A Stirling engine is an external combustion closed-cycle reciprocating piston thermal engine, also known as a hot air engine, and its thermal cycle is the Stirling cycle. When a Stirling engine operates, the working fluid independent of the gas absorbs heat through a heater and does work externally according to the Stirling cycle; thus, it avoids the knocking work and intermittent combustion process similar to internal combustion engines, thereby achieving high efficiency, low noise, and low emission operation. Because the working fluid of the Stirling engine is an independent closed cycle, it can operate as long as there is a heat source or a cold source. It is suitable for ammonia phase change heat transfer technology, comprehensively utilizes the cold energy generated by the vaporization phase change endothermic of liquid ammonia and the dissolution heat released by ammonia dissolving in water, and develops a zero-emission ammonia energy Stirling engine. Summary of the Invention

[0005] The object of the present invention is to provide a Stirling engine device based on ammonia phase change heat exchange technology, and to realize the design and development of a zero-emission ammonia energy Stirling engine.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0007] A Stirling engine device based on ammonia phase change heat exchange technology, the device includes a liquid ammonia supply module, an ammonia vaporizer, an ammonia injector, a pure water supply module, an ammonia-water mixing heat exchanger, a Stirling engine, and an ammonia-water recovery module;

[0008] The outlet of the liquid ammonia supply module supplies liquid ammonia with stable pressure to the outside, and the liquid ammonia in the ammonia vaporizer absorbs heat and vaporizes to generate cold energy through a phase change;

[0009] The ammonia injection system supplies ammonia with a set flow rate to the outside;

[0010] The pure water supply module supplies pure water with a set pressure and flow rate to the outside;

[0011] In the ammonia-water mixing heat exchanger, ammonia and water are mixed and dissolved to release the heat of dissolution;

[0012] The Stirling engine includes an expansion chamber, a heater, a regenerator, a cooler, and a compression chamber that are connected in sequence. The expansion chamber, heater, regenerator, cooler, and compression chamber are filled with a working medium; the cooler is internally provided with an ammonia vaporizer, and the liquid ammonia inlet of the ammonia vaporizer is connected to the outlet of the liquid ammonia supply module; the heater is internally provided with an ammonia-water mixing heat exchanger, the pure water inlet of the ammonia-water mixing heat exchanger is connected to the outlet of the pure water supply module, and the ammonia inlet of the ammonia-water mixing heat exchanger is connected to the outlet of the ammonia injector;

[0013] The inlet of the ammonia injector is connected to the outlet of the ammonia vaporizer;

[0014] The inlet of the ammonia-water recovery module is connected to the outlet of the ammonia-water mixture of the ammonia-water mixing heat exchanger.

[0015] Further, the liquid ammonia supply module is composed of a liquid ammonia storage tank, a liquid ammonia pump, and a liquid ammonia pressure stabilizer connected in sequence.

[0016] Further, the range of the liquid ammonia pressure supplied by the liquid ammonia supply module to the outside is 0.1 MPa - 2.5 MPa.

[0017] Further, the pure water supply module is composed of a pure water storage tank, a water pump, and a nozzle connected in sequence.

[0018] Further, the range of the pure water pressure supplied by the pure water supply module to the outside is 0.1 MPa - 2.5 MPa.

[0019] Further, ammonia and water are mixed in the ammonia-water mixer, and ammonia dissolves in water to release the heat of solution.

[0020] Further, the packing of the regenerator is a porous medium, and preferably a wire mesh.

[0021] Further, the Stirling engine includes a crank-link Stirling engine and a free-piston Stirling engine.

[0022] Further, the Stirling engine device based on ammonia phase change heat transfer technology further includes a control system, which is communicatively connected to the ammonia supply module, the ammonia injector, the pure water supply module, the Stirling engine and the ammonia-water recovery module, and is used to realize the operation control of the whole machine and the recovery and storage of the product ammonia water.

[0023] Beneficial effects:

[0024] 1. Utilize the cold generated by the vaporization phase change of liquid ammonia to cool the working medium, further reduce the cold-end temperature and improve the efficiency of the Stirling engine; and utilize the heat of solution released by ammonia dissolving in water to realize the comprehensive utilization of energy.

[0025] 2. There is no ammonia combustion reaction in the energy utilization process of the present invention, and no tail gas pollutants are emitted.

[0026] 3. The present invention fills liquid ammonia and pure water, and the product ammonia water is recycled, achieving zero emissions.

[0027] 4. The control system is suitable for the comprehensive control and calibration of the Stirling engine based on ammonia phase change heat transfer technology, and can cooperate with the load control of the ammonia injector to adjust the operating conditions of the engine device in real time. Description of the drawings

[0028] Figure 1 is a schematic diagram of the principle of a Stirling engine device based on ammonia phase change heat transfer technology of the present invention.

[0029] Wherein: 1 is a liquid ammonia supply module, 2 is a cooler, 2-1 is an ammonia vaporizer, 3 is a regenerator, 4 is a pure water supply module, 5 is a heater, 5-1 is an ammonia-water mixer, 6 is an ammonia injector, 7 is an expansion chamber, 8 is a compression chamber, 9 is an ammonia-water recovery module, and 101 is a control system. Specific embodiments

[0030] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the protection scope of the present invention.

[0031] Embodiment

[0032] This embodiment discloses a Stirling engine device based on ammonia phase change heat transfer technology, including:

[0033] A liquid ammonia supply module 1, an ammonia vaporizer 2-1, an ammonia injector 6, a pure water supply module 4, an ammonia-water mixing heat exchanger 5-1, a Stirling engine, and an ammonia-water recovery module 9;

[0034] The Stirling engine includes an expansion chamber 7, a heater 5, a regenerator 3, a cooler 2, and a compression chamber 8 that are connected in sequence, and a working fluid is filled therein;

[0035] The cooler 2 integrates an ammonia vaporizer 2-1. The liquid ammonia inlet of the ammonia vaporizer 2-1 is connected to the outlet of the liquid ammonia supply module 1, and its outlet is connected to the inlet of the ammonia injector 6;

[0036] The heater 5 integrates an ammonia-water mixing heat exchanger 5-1. The pure water inlet of the ammonia-water mixing heat exchanger 5-1 is connected to the outlet of the pure water supply module 4, and its ammonia gas inlet is connected to the outlet of the ammonia injector 6;

[0037] The inlet of the ammonia-water recovery module 9 is connected to the ammonia-water mixture outlet of the ammonia-water mixing heat exchanger 5-1;

[0038] Wherein, the ammonia vaporizer 2-1 provides cooling capacity for the cooler 2 by absorbing heat through liquid ammonia vaporization phase change, and the ammonia-water mixing heat exchanger 5-1 provides heat for the heater 5 by releasing dissolution heat when ammonia gas dissolves in water, realizing the combustion-free and zero-emission operation of the Stirling engine.

[0039] The principle and operation process of this embodiment device are further described below with reference to the accompanying drawings:

[0040] As Figure 1As shown in the figure, a Stirling engine device based on ammonia phase change heat transfer technology. The device mainly includes that the outlet of the liquid ammonia supply module 1 can supply liquid ammonia with relatively stable pressure outward, and the optional pressure range is 0.1 MPa - 2.5 MPa, and the flow rate is controllable. The liquid ammonia inlet of the ammonia vaporizer 2-1 in the cooler 2 is connected to the outlet of the liquid ammonia supply module 1, and the outlet end of the ammonia vaporizer 2-1 is connected to the inlet of the ammonia injector 6. The cooling capacity generated by the liquid ammonia vaporization phase change endotherm in the ammonia vaporizer 2-1 is about 16% of the calorific value of ammonia gas, which is used for the cooler 2 to cool down the working medium at the cold end of the Stirling engine. The pure water supply module 4 can supply pure water with set pressure and flow rate outward, and the optional pressure range is 0.1 MPa - 2.5 MPa. The ammonia inlet of the ammonia-water mixing heat exchanger 5-1 in the heater 5 is connected to the outlet of the ammonia injector 6, and the pure water inlet of the ammonia-water mixing heat exchanger 5-1 is connected to the outlet of the pure water supply module 4. The heat of solution generated by ammonia gas dissolving in water in the ammonia-water mixing heat exchanger 5-1 is about 11% of the calorific value of ammonia gas, which is used for the heater 5 to heat up the working medium at the hot end of the Stirling engine. The ammonia-water mixing heat exchanger 5-1 and the heater 5 are designed in combination. The ammonia-water mixture outlet of the ammonia-water mixing heat exchanger 5-1 is connected to the inlet of the ammonia-water recovery module 9, and the ammonia-water recovery module 9 is used to store the ammonia-water mixture generated during the operation of the device. The regenerator 3 is arranged between the cooler 2 and the heater 5 to play a role in heat storage. When the working medium gas absorbs heat and expands, the high-temperature gas flow flows from the hot-end heater 5 and the expansion chamber 7 through the regenerator 3 to the cold-end cooler 2 and the compression chamber 8, and the regenerator 3 stores most of the sensible heat of the gas; when the working medium is cooled and compressed, the low-temperature gas flow then returns from the cold end to the hot end through the regenerator 3, and the regenerator 3 releases the stored heat to the low-temperature gas flow to complete heat regeneration. Good heat regeneration performance can greatly reduce the working load of the heater and the cooler, and improve the power and efficiency of the engine. The commonly used filler of the regenerator 3 is metal wire mesh, which is a typical porous medium component. The Stirling engine mainly consists of five parts: an expansion chamber 7, a heater 5, a regenerator 3, a cooler 2, and a compression chamber 8. The working medium can adopt a gas working medium with good heat transfer performance, usually helium, hydrogen, etc.; the working medium undergoes cooling, compression, heat absorption, and expansion in each part for a cycle of operation to output power. The Stirling engine includes a crank-link Stirling engine and a free-piston Stirling engine. The control system 101 communicates with the liquid ammonia supply module 1, the ammonia injector 6, the pure water supply module 4, the Stirling engine, and the ammonia-water recovery module 9 to jointly form the overall integrated control system of the present invention, and regulates the engine operation power output and the recovery and storage of the product ammonia-water.

[0041] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, makes equivalent substitutions or changes, and all should be covered within the protection scope of the present invention.

Claims

1. A Stirling engine device based on ammonia phase change heat transfer technology, characterized in that: The device comprises a liquid ammonia supply module, an ammonia vaporizer, an ammonia gas injector, a pure water supply module, an ammonia-water mixing heat exchanger, a Stirling engine and an ammonia water recovery module; The outlet of the liquid ammonia supply module supplies liquid ammonia with stable pressure to the outside, and the liquid ammonia in the ammonia vaporizer absorbs heat and vaporizes and changes phase to generate cold energy; The ammonia injector supplies ammonia at a set flow rate to the outside; The pure water supply module supplies pure water with set pressure and flow rate to the outside; Ammonia gas and water are mixed and dissolved in the ammonia-water mixing heat exchanger to release heat of solution; The Stirling engine comprises an expansion chamber, a heater, a regenerator, a cooler and a compression chamber which are connected in sequence, wherein the expansion chamber, the heater, the regenerator, the cooler and the compression chamber are filled with a working medium; the cooler is equipped with an ammonia vaporizer, and the liquid ammonia inlet of the ammonia vaporizer is connected to the outlet of the liquid ammonia supply module; the heater is equipped with an ammonia-water mixing heat exchanger, and the pure water inlet of the ammonia-water mixing heat exchanger is connected to the outlet of the pure water supply module, and the ammonia inlet of the ammonia-water mixing heat exchanger is connected to the outlet of the ammonia injector; The inlet of the ammonia injector is connected to the outlet of the ammonia vaporizer; The inlet of the ammonia water recovery device is connected to the ammonia water mixture outlet of the ammonia-water mixing heat exchanger.

2. A Stirling engine device based on ammonia phase change heat transfer technology according to claim 1, characterized in that: The liquid ammonia supply module is composed of a liquid ammonia storage tank, a liquid ammonia pump and a liquid ammonia pressure stabilizer which are connected in sequence.

3. A Stirling engine device based on ammonia phase change heat transfer technology according to claim 1, characterized in that: The liquid ammonia supply module supplies liquid ammonia at a pressure in the range of 0.1 MPa-2.5 MPa.

4. A Stirling engine device based on ammonia phase change heat transfer technology according to claim 1, characterized in that: The pure water supply module is composed of a pure water storage tank, a water pump and a nozzle which are connected in sequence.

5. A Stirling engine device based on ammonia phase change heat transfer technology according to claim 1, characterized in that: The pure water supply module supplies pure water at a pressure ranging from 0.1 MPa to 2.5 MPa.

6. A Stirling engine device based on ammonia phase change heat transfer technology according to claim 1, characterized in that: The ammonia-water mixing heat exchanger is used to mix ammonia gas with water, and the ammonia gas dissolves in water to release heat of solution.

7. The Stirling engine device based on ammonia phase change heat transfer technology according to claim 1, characterized in that: The filler of the regenerator is a porous medium.

8. The Stirling engine device based on ammonia phase change heat transfer technology according to claim 1, characterized in that: The filler of the regenerator is a metal wire mesh.

9. The Stirling engine device based on ammonia phase change heat transfer technology according to claim 1, characterized in that: The Stirling engine includes a crank-connecting rod Stirling engine and a free piston Stirling engine.

10. The Stirling engine device based on ammonia phase change heat transfer technology according to claim 1, characterized in that: The Stirling engine device based on ammonia phase change heat transfer technology also includes a control system, which is communicatively connected to the liquid ammonia supply module, the ammonia injector, the pure water supply module, the Stirling engine and the ammonia water recovery module, and is used to realize the operating condition control of the whole machine and the recovery and storage of the product ammonia water.

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