RU2116460C1 - Method of operation of pneumatic motor and device for its realization (versions) - Google Patents

Abstract

FIELD: mechanical engineering: conversion of thermal energy into mechanical energy. SUBSTANCE: with pneumatic motor operating, working medium is delivered into motor chamber where it expands, then delivery is stopped at moment when piston is in bottom dead center, and cooling agent is injected into closed space surrounding the chamber. When piston reaches top dead center, evaporated cooling agent is discharged. Cooling agent can be subsequently used as working medium in other pneumatic motor. Device has chamber, piston with crank gear, cooling agent nozzle, closed space surrounding the chamber and connected with space between lower cover of chamber and piston. Device can be provided with closed space surrounding the chamber and communicating with chamber of other pneumatic motor mechanically coupled with first pneumatic motor. EFFECT: effective conversion of thermal energy into mechanical energy with no adverse effect on environment. 4 cl, 4 dwg

Description

 The invention relates to engine building and the conversion of thermal energy into mechanical energy without harmful environmental consequences.

 A known method of operation of a pneumatic engine fed by compressed air. Before use in the engine, air is mixed with hydrogen and oxidized in a catalytic chamber, thereby increasing its temperature [1]. But to implement this method, it is necessary to have a supply of compressed air and hydrogen, which is bulky and unsafe.

 During the operation of a piston air motor, ambient heat, in particular air, is used [2]. For this, the air in the working chamber is cooled by injection of refrigerant into the chamber. In this case, the pressure in it drops. The piston moves under the action of the differential pressure, doing useful work. Then the process of filling the working chamber, injection of refrigerant, making the piston's effective stroke and emptying the working chamber are repeated.

 The principal difference of this method is that the process of heating the working fluid in the engine chamber and obtaining useful work by expanding it has been replaced by the process of cooling the working fluid, lowering the pressure in it, as a result of which the environment performs useful work by compressing the working fluid. The absorption of heat in the chamber is carried out using the refrigerant introduced into the chamber, which is the heat accumulator.

 For the effective operation of such an engine, it is necessary to absorb a significant amount of heat of the working fluid. Otherwise, the decrease in temperature and pressure will be insignificant, which will make the engine ineffective from the point of view of obtaining useful work. Therefore, the refrigerant must be highly absorbent, i.e. low heat content and low temperature in relation to the environment, in addition, it must be environmentally friendly. Most suitable for these purposes are cryogenic liquids - liquid air, liquid nitrogen. However, during evaporation, i.e., in the process of heat absorption, the vapors of these liquids occupy a significant volume in the working chamber because of their low density, which leads to a general increase in pressure in the working chamber and to a decrease in the efficiency of the engine.

 To overcome this drawback and increase the efficiency of such an engine, it is proposed to implement the following method of its operation and engine design options.

 In FIG. 1 shows a cyclogram of the working process in the chamber of the air motor; in FIG. 2 - a sequence diagram of the process of obtaining additional useful work when using refrigerant vapor as a working fluid; in FIG. 3 - air motor (option 1); in FIG. 4 - air motor (option 2).

 Consider the sequence diagram of the workflow (Fig. 1).

 In section 2 - 3 (Fig. 1), the chamber is connected to the environment and there is an expansion cycle — the chamber volume increases at constant pressure, then the valve connecting the chamber to the environment is closed and liquid refrigerant is injected into the cavity surrounding the chamber.

 Through the walls of the chamber, heat from the working fluid passes to the refrigerant, the pressure in the chamber drops along isochore 3-4 and the piston, under the influence of environmental pressure, begins to move in the opposite direction, doing useful work and reducing the volume of the working chamber. If this process were adiabatic, then the process would go along the adiabat 4-1 and useful work would be determined by the area of the figure formed by points 2-3-4-1. But since heat is exchanged between the chamber and the cavity, the process proceeds along the 4-1 'isotherm.

 On the site 1 '- 2' is the exhaust of the working fluid from the chamber.

 With this method of engine operation, there is no harmful effect of the evaporated refrigerant on the amount of vacuum in the chamber, since the refrigerant vapor does not enter the chamber. In addition, since the working stroke is carried out with the removal of heat, in the cycle you can get a lot of work (the area of the plot formed by points 2'-3 '- 4' - 1 'in Fig. 1).

 But, besides this, you can get additional work using the evaporated refrigerant in another air motor as a working fluid. In confirmation of this, we consider the sequence diagram shown in FIG. 2.

At point 1 in the cavity surrounding the working chamber, the pressure is atmospheric. At the time of injection of refrigerant in section 1 - 2, the pressure increases due to the supply of heat from the chamber and the evaporation of liquid refrigerant. Then, the evaporated refrigerant from the cavity under pressure p ₂ enters the chamber of the second air motor and expands adiabatically. If the expansion of the refrigerant occurs during the compression cycle in the first air motor, then heat is exchanged between the working fluid of the first air motor and the refrigerant, as a result of which the expansion of the refrigerant vapor expands isothermally (section 2 - 3 '). At section 3 '- 4', the exhaust valve of the second air motor opens and the pressure in its chamber becomes atmospheric (point 4 '). Then the refrigerant is released into the atmosphere (section 4 '- 1). Additional useful work is determined by the area of the figure formed by points 2 - 3'- 4'- 1. Thus, the technical result achieved by the invention is to increase the efficiency of the air motor by increasing the degree of vacuum in the working chamber and the possibility of using refrigerant vapor for getting extra work.

 As a device that implements the method described above, a pneumatic motor is proposed, the circuit of which is shown in figure 3 (option 1).

 The engine consists of a chamber 1, a valve 2 for the inlet and outlet of the working fluid, a piston 3, a connecting rod 4, a crank 5 forming a crank mechanism, nozzles 6 for refrigerant injection, a closed cavity 7 surrounding the chamber 1, an inlet channel 8 connecting the cavity 7 with a volume 9 of the chamber 1, intended for the evaporated refrigerant and formed by the lower cover 10 of the chamber 1 and the reverse side of the piston 3, valve 11 for the release of refrigerant vapor, flywheel 12.

 The operation of the engine is as follows. In the position of the bottom dead center of the piston 3, the valves 2 and 11 are closed. Through the nozzle 6, refrigerant is injected into the cavity 7. The temperature in the cavity 7 decreases, the heat from the working fluid from the chamber 1 through the walls enters the cavity 7 and the refrigerant evaporates. The pressure in the chamber 1 drops, and in the cavity 7 increases. Under the influence of environmental pressure and refrigerant vapor, the piston 3 moves up, due to which the crank 5 is rotated, i.e., the engine travels. When equalizing the pressure in the chamber 1, cavity 7 and the environment, the valves 2, 11 open, making it possible to discharge the working fluid and refrigerant vapor into the environment. Due to the energy accumulated in the flywheel 12 when the piston 3 moves down with the valves 2 and 11 open, the chamber 1 is filled with a new portion of the working fluid and the refrigerant vapor is ejected. Then the valves 2 and 11 are closed and the process is repeated.

 The device can be made in such a way that a closed cavity surrounding the engine chamber is connected to the working chamber of another engine kinematically connected with the first (option 2).

 In FIG. 4 shows a diagram of such a device consisting of a chamber 1, a valve 2 for inlet and outlet of a working fluid, a piston 3 with a connecting rod 4, a crank 5, a nozzle 6 for refrigerant injection, a cavity 7 surrounding the working chamber 1, an inlet channel 8 connecting the cavity 7 with a chamber 9 for evaporated refrigerant, a piston 13 and a connecting rod 14, mounted on a crank 5, a valve 11 for releasing refrigerant vapor from the engine, flywheel 12.

 The engine operates as follows. In the position of the bottom dead center of the piston 3 and the top dead center of the piston 13, the valves 2 and 11 are closed. Through the nozzle 6, refrigerant is injected into the cavity 7. The temperature in the cavity 7 decreases, the heat from the working fluid from the chamber 1 through the walls enters the cavity 7 and goes to the evaporation of the refrigerant. The pressure in the chamber 1 drops, and the pressure in the cavity 7 increases. Under the influence of environmental pressure, the piston 3 moves up, and under the action of vapor pressure of the refrigerant, the piston 13 moves down, due to which the crank is rotated, i.e., the engine travels. When equalizing the pressure in chambers 1 and 9 and the environment, valves 2 and 11 open, providing the possibility of discharge of the working fluid and refrigerant vapor into the environment. Due to the accumulated energy in the flywheel 12 when the piston 3 moves down with the valve 2 open, the working chamber 1 is filled with a new portion of the working fluid. At the same time, with the valve 11 open, the piston 8 moves upward, pushing the refrigerant vapor out of the chamber 9 into the environment. After that, the valves 2 and 11 are closed and the process is repeated.

 The proposed device allows not less than double the efficiency of the engine compared to the prototype.

 Sources of information.

 1. Serov V. I. The way the machine works. USSR copyright certificate N 663858, cl. F 01 B 23/06, 1979.

 2. Burikov V. S. The method of operation of a piston air motor. USSR author's certificate N 1818478, cl. F 01 B 23/06, 1993.

Claims (4)

 1. The method of operation of the piston air motor, including the supply of the working fluid to the engine chamber, its expansion, the cessation of the flow of the working fluid when the piston is at the bottom dead center (BDC) and the injection of refrigerant, the resumption of the flow of the working fluid when the piston reaches top dead center (TDC) characterized in that the refrigerant is injected into the enclosed chamber in the surrounding chamber, and when the piston reaches the top dead center, the evaporated refrigerant is discharged.  2. The method according to claim 1, characterized in that the evaporated refrigerant is used as a working fluid in another air motor.  3. A device for implementing the method of operation of an air motor, consisting of a chamber with a valve for inlet and outlet of the working fluid, a piston with a crank mechanism and a nozzle for refrigerant injection, characterized in that the nozzle is located in a closed cavity surrounding the chamber connected to the volume formed the bottom cover of the chamber and the reverse side of the piston of the air motor.  4. A device for implementing the method of operation of an air motor, consisting of a chamber with a valve for inlet and outlet of a working fluid, a piston with a crank mechanism and a nozzle for refrigerant injection, characterized in that the nozzle is located in a closed cavity surrounding the chamber connected by a channel to the chamber of another kinematically connected to the first air motor.

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