RU2353789C2 - Method for preparation of fuel for combustion in process of internal combustion engine thermal pollutants recycling - Google Patents

Abstract

FIELD: engines and pumps.

SUBSTANCE: invention is related to internal combustion engines (ICE), in which fuel is prepared to combustion due to application of thermal energy in process of deep cooling of combustion products heat, recycling of heat with water of primary circuit and oil. Mixing, heating, evaporation are performed during combined expansion in narrowing part of Laval nozzle of previously compressed liquid fuel and superheated steam that realise suction of primary hot combustion products, oxidation of carbohydrates down to alcohols and aldehydes is realised in expanding part of Laval nozzle during suction of secondary combustion products, electric heating of fuel is introduced for realisation of the same physical and chemical stage of fuel preparation in period of start-up, at that superheated water steam is produced in process of return condensate and initial water heating in condensation stage from hot combustion products, oil cooler, primary circuit water cooler, and also heat of combustion products during boiling and superheating under vacuum pulled by vacuum pump, in evaporating stage and is also sent to heating system, heat exchanger of hot water supply system and to technological consumers, at that it is collected as condensate into condensate return tank.

EFFECT: increased power, thermal efficiency and reduction of amount of ecologically hazardous components produced by internal combustion engine.

1 dwg

Description

The invention relates to internal combustion engines (ICE), in which the preparation of fuel for combustion due to the use of thermal energy during the deep cooling of the heat of the combustion products, utilization of heat with water of the primary circuit and oil is performed.

A device for the integrated heat recovery of the internal combustion engine [1] provides cooling of the primary circuit water in a water-to-water heat exchanger to an intermediate closed-circuit heat carrier, which is then additionally heated in the first gas-water heat exchanger by the engine exhaust heat to a temperature of 95 ° C and sent to heating radiators, the flow rate through which regulated by a locking authority. From the radiator, an intermediate heat carrier with a temperature of 70 ° C is circulated by a circulation pump to a second water-water heat exchanger, where it is cooled to a temperature of about 50 ° C and then again enters the first water-water heat exchanger. Raw water is first heated in a gas-water heat exchanger from 5 to 25 ° C, and then in a second water-water heat exchanger to 45 ° C. The temperature of the combustion products at the outlet of the exhaust pipe is below the dew point temperature.

Exhaust gas cooling is associated with condensation of water vapor. The exhaust pipe is located vertically. After some time, the condensate will fill the exhaust pipe and the engine will stall. Another drawback is that the raw water is heated as part of the internal combustion engine thermal circuit and an additional third pipe is allocated for the needs of hot water supply. The water temperature in the return line before the circulation pump is only theoretically equal to 70 ° C. Due to the losses that are present in heating networks, this temperature is significantly lower, and therefore it is not possible to heat water to 45 ° C for the needs of hot water supply. In addition, the presented device does not cover the heat that is removed when cooling the oil.

During operation of the internal combustion engine [2], part of the fuel is supplied to the cylinders in a liquid state. The remainder, before being fed into the inlet pipe, is gasified and mixed with water vapor. A change in their state of aggregation is achieved due to the heat of the combustion products.

The main disadvantage is that the heat of the combustion products is not fully used. Using the heat of the primary water only allows you to evaporate fuel and water, but to achieve thermal decomposition of the fuel is problematic.

Part of the exhaust gas [3] leaving the exhaust manifold is directed to the receiver, and the other is fed under the fuel layer to the reactor. The fuel is sparged with exhaust gases, heats up and evaporates. This mixture is ejected by the exhaust gases not cooled in the fuel, mixed with them, additionally heated and fed into the reactor. In the reactor, the fuel reacts with CO ₂ , HO ₂ . Under the influence of the heat of combustion products, H ₂ , CO, and radicals are formed. This mixture enters the cylinders and burns together with the main fuel.

In this case, it is difficult to quantitatively control the water vapor entering together into the reactor. Losses of heat with flue gases are still quite large, since they are removed to the atmosphere with high temperature.

The aim of the invention is to increase power, thermal efficiency and reduce the number of environmentally harmful components of an internal combustion engine.

This goal is achieved by the fact that in the method of preparing fuel for combustion during the utilization of thermal emissions of an internal combustion engine by evaporation, gasification, mixing with recirculation gases, which are directed for combustion into the engine cylinders, according to the invention, mixing, heating, evaporation are carried out with joint expansion in the narrowing part of the Laval nozzle of pre-compressed liquid fuel and superheated steam, which carry out the suction of primary hot combustion products, oxidation of hydrocarbons to alcohols and of ice ligides was performed in the expanding part of the Laval nozzle during suction of secondary combustion products, electric heating of the fuel was introduced to implement the same physical and chemical stage of fuel preparation during the start-up period, and superheated water vapor was obtained by heating the return condensate and the source water in the condensation stage from the hot combustion products, oil cooler, water cooler of the primary circuit, as well as from the heat of combustion products during boiling and overheating under vacuum created by a vacuum pump, in the evaporation stage and It is also sent to the heating system, the heat exchanger of the hot water supply system and technological consumers, and is collected in the form of condensate in a condensate return tank.

The scheme for preparing fuel for combustion during utilization of thermal emissions of ICE includes: 1 - generator; 2 - diesel; 3 and 4 - condensation and evaporation stages; 5 - pump; 6 - oil cooler; 7 - oil pump; 8 - water pump of the primary circuit; 9 - water cooler of the primary circuit; 10, 13, 25, 28, 29 - control valves; 11 - a vacuum pump; 12 - air blower; 14 - condensate return tank; 15, 23 - primary and secondary pipeline of combustion products; 16 and 17 - return and direct pipeline; 18 - contact camera; 19 - condensate drain pipe; 20 - condensation heat exchanger; 21 - hot water heater; 22 - heating system; 24, 26 - narrowing and expanding parts of the Laval nozzle; 27 - electric heating element; 30 - manufacturing consumer; 31 - fuel pump.

Diesel 2 together with generator 1 are a stationary, permanent power plant. It includes a water cooling system of the primary circuit 9, an oil cooling system 6, which is part of the lubrication system, and a deep cooling system of the combustion products 20. These systems take about 50-60% of the supplied energy in the form of heat.

Thermal emissions are useful for preparing fuel for burning and receiving steam, which is sent to a heat-receiving complex consisting of a heating system 22, heating water for hot water supply in a heat exchanger 21 and a production consumer 30. The condensate is drained into the condensate return tank 14 and pump 5 together with additional raw water enters the heat transfer complex. Water is heated in the condensation stage 3, oil cooler 6, water cooler of the primary circuit 9. The vacuum pump 11 creates a vacuum in the evaporation stage 4. Water boils at a temperature below 100 ° C. The steam overheats and is compressed by a vacuum pump 11 to a pressure of approximately 0.25 MPa. It enters the heat-receiving complex and at the entrance of the narrowing part of the Laval nozzle 24.

Condensation heat exchanger 20 consists of sequentially along the combustion products located evaporative stage 4, the contact chamber 18 and the condensation stage 3.

The heat exchange from the side of the combustion products in the condensation stage is complex. It includes convection and condensation of water vapor from combustion products. The composition of the combustion products of the condensation stage includes nitrogen, oxygen, carbon dioxide, water vapor and condensate droplets. The movement of the flow is carried out from the bottom up, and the condensate under the influence of gravity falls down. The diffusive mass flow is directed from the gas stream to the inner wall of the pipe. It changes the amount of water vapor along the entire length of the heat-exchange element and, as a result, the specific volumes and the thermophysical properties of the gas stream for i-ro section become variable. The presence of a phase transition of water vapor significantly increases the generalized heat transfer coefficient from the gas side. This entails a significant reduction in the overall dimensions of the stage.

The contact chamber 18 (the device is not shown) is designed to ensure that both types of heat and mass transfer are in 3rd place when the engine load changes in the condensation stage. In this case, the generalized heat and mass transfer coefficient is an order of magnitude larger than just one convective heat transfer coefficient. Condensate flows from the condensation stage to the condensate collector and is removed from the contact chamber by a condensate discharge pipe 19.

The boiling point in the evaporation stage 4 (device not shown) depends on the magnitude of the vacuum. It is smaller than 100 ° C. On the part of the combustion products, heat is transferred to the wall of the stage by convection. The scale-like salts dissolved in water on heat exchange surfaces are deposited to a lesser extent than under elevated pressure. They, along with sludge-like salts, are periodically removed from the lowest points of the water volume (not shown). The designs of the condensation stage, the contact chamber and the evaporation stage are determined by thermal calculation.

At the entrance to the narrowing part of the Laval nozzle 24, pipelines of fuel, superheated steam and primary combustion products 15 are connected. The fuel pressure is created by the fuel pump 31. The temperature of the combustion products is approximately 500 ° C. The expansion from the narrowing part of the Laval nozzle 24 of liquid fuel and water vapor creates a vacuum, due to which primary combustion products are sucked in by the pipe 15. The liquid fuel in the narrowing part of the nozzle is heated to about 200 ° C by supplying heat from superheated steam and combustion products. In this case, it completely evaporates. The physical stage of preparing fuel for combustion is nearing completion.

In the transition zone located between the narrowing 24 and expanding 26 parts of the Laval nozzle, the pipeline of secondary products of combustion 23. They have a temperature equal to the temperature of the primary products of combustion. Secondary combustion products are also sucked up due to vacuum. The temperature of the mixture reaches about 300 ° C. The passage time of the mixture is sufficient so that before the mixture flows from the expanding part of the nozzle 26, the process of preliminary oxidation of hydrocarbons, which relates to the chemical stage of preparing the fuel for combustion, is completely completed. At this stage, hydrocarbons add oxygen in the products of combustion to form alcohols and aldehydes. The resulting alcohols and aldehydes are further oxidized to formaldehyde. At the exit of the expanding part of the nozzle, the speed of the mixture decreases, but the pressure increases. Quantitative regulation of the supply of source fuel, superheated steam, primary and secondary combustion products is achieved using the appropriate control valves 25, 13, 28, 29 and 10.

The prepared gas mixture is supplied together with the air compressed in the air blower for combustion into the internal combustion engine cylinder. Thus prepared fuel in the form of formaldehyde burns without the formation of CO and soot. The presence in the fuel mixture of water vapor and recirculated combustion products reduces the amount of nitrogen oxides generated during combustion.

The fuel preparation for combustion at the start of the internal combustion engine is performed using an electric heating element 27 located in the tapering 24 and expanding 26 parts of the Laval nozzle.

The advantages of the proposed method of preparing fuel for combustion during utilization of thermal emissions of an internal combustion engine are that:

1. Thermal emissions of internal combustion engines are fully useful inside the cycle and by various consumers, up to the condensation of water vapor from the combustion products. This increases the thermal efficiency of the cycle by about 50 ... 60%.

2. The preparation of the physical and chemical stages of hydrocarbon liquid fuel is such that it excludes the possibility of its thermal decomposition. Otherwise, the combustion products would have included CO and soot.

Literature

1. Copyright certificate No. 1687834. Device for the integrated utilization of heat of an internal combustion engine.

2. Copyright certificate No. 1545002. The method of operation of the internal combustion engine.

3. Copyright certificate No. 1633155. The method of operation of the internal combustion engine.

Claims (1)

A method of preparing fuel for combustion during utilization of thermal emissions of an internal combustion engine by evaporation, gasification, mixing with recirculation gases, which are directed to combustion into engine cylinders, characterized in that the mixing, heating, and evaporation are performed by joint expansion in the narrowing part of the Laval nozzle, previously compressed liquid fuels and superheated steam, which carry out the suction of primary hot combustion products, oxidation of hydrocarbons to alcohols and aldehydes is performed in an expanding of the Laval nozzle during suction of secondary combustion products, electric heating of the fuel was introduced to implement the same physical and chemical stages of fuel preparation during the start-up period, and superheated water vapor was obtained by heating the return condensate and source water in the condensation stage from the hot combustion products, oil cooler, water cooler primary circuit, as well as from the heat of combustion products during boiling and overheating under vacuum, created by a vacuum pump in the evaporation stage and also sent to the heating system, t ploobmennik hot water system technology and consumers, and collected as a condensate in the condensate return tank.