RU2330982C1 - Method of feeding internal combustion engine with cryogenic fuel - Google Patents

Abstract

FIELD: engines and pumps.

SUBSTANCE: invention relates to machine building, particularly, to internal combustion engines firing liquefied cryogenic fuels, e.g. propane-butane, natural gas, hydrogen and the like. In refueling, the cryogenic fuel is fed and kept in heat-insulated vessel in liquid state at cryogenic temperature. In engine operation, the said fuel is fed into a heat accumulator, heated up therein to gaseous state, mixed up with air and fed into the engine combustion chamber. During the first refueling, cryogenic fuel is fed and kept in a heat-insulated tank. In engine operation, with the said fuel heated in the heat accumulator, the accumulator adapter is cooled and kept at cryogenic temperature, during the subsequent refueling, gaseous cryogenic fuel at normal temperature is fed into the heat accumulator to be cooled to cryogenic temperature. The accumulator adaptor is kept at normal temperatures, while cryogenic fuel is fed and kept in heat-insulated tank at cryogenic temperature. Invention allows reducing refueling costs, increasing safety and simplifying engine operation.

EFFECT: higher engine reliability, easier operation, lower refueling costs.

3 ex

Description

The invention relates to mechanical engineering, in particular to internal combustion engines operating on liquefied cryogenic fuels, such as propane-butane, natural gas, hydrogen and others.

Known internal combustion engines operating on gaseous fuels with the conversion of liquid fuel into gaseous by heating.

A device is known (see AU USSR No. 1281720), in which gasification of fuel is carried out in an operating mode in a heat exchanger heated by exhaust gases.

A device is known (see USSR AS No. 1416733), in which fuel gasification is also carried out by the heat of exhaust gases.

A device is known (see AS USSR No. 1638347), in which the fuel is evaporated by electric heating elements before entering the engine intake manifold.

A known power system (see RF patent No. 2001300), in which the compressed gas before being fed into the engine is heated in the evaporator with warm liquid cooling the engine.

There is also a method of powering the Chumakov internal combustion engine (see RF patent No. 2074970), in which gas fuel is taken from the source in the liquid phase, after cleaning, it is heated in the evaporator with warm engine coolant and fed to the intake manifold.

A device is also known (see RF patent No. 2118689) in which gas from a gas-liquid cylinder is heated in the evaporator with warm engine coolant.

The disadvantage of all these engines is the need to place liquefied cryogenic fuel cylinders in the engine.

A liquefied natural gas engine power supply system is also known, comprising an isothermal cryogenic liquid gas cylinder and a sealed gas chamber in which the vapor gas is heated by exhaust gases from the engine (see RF patent No. 2095611). The disadvantage of this engine is the need to refuel the engine only with liquefied cryogenic fuel each time.

A device for heating an internal combustion engine running on liquefied petroleum gas according to the patent of the Russian Federation No. 2190121 is also known. The device for heating liquefied gas uses a heat accumulator connected to the path of the engine cooling system. The method of operation of the latter device is taken as a prototype of the proposed method.

The disadvantage of this engine is the need to refuel only in a liquefied state, as well as the inclusion of a liquefied gas heating system in addition to a heat accumulator. These drawbacks become critical when using low boiling fuels such as natural gas and hydrogen.

The objective of the present invention is to remedy these disadvantages of the prototype, namely obtaining the possibility after the first refueling of several refuelings of the engine with gaseous fuel of normal temperature. In addition, the fuel heating system dependent on it is excluded from the engine. This greatly simplifies the design and operation of the engine and opens up the possibility of using low-boiling fuels.

The essence of the proposed method lies in the fact that the known actions, when cryogenic fuel is supplied and stored in a heat-insulated vessel in a liquid state at a cryogenic temperature during refueling, when the engine is running, cryogenic fuel is fed into a heat accumulator, heated in it to a gaseous state, mixed with air and fed into the combustion chamber of the engine, supplemented with those proposed, when at the first refueling cryogenic fuel is fed and stored in a heat-insulated tank, when the engine is running when the cryogenic fuel is heated willow in the heat accumulator is cooled and stored in the battery nozzle at a cryogenic temperature, and at subsequent refueling, cryogenic fuel in a gaseous state at normal temperature is fed into the heat accumulator and cooled in it to a cryogenic temperature, while the battery nozzle is heated and stored at normal temperature, and cryogenic fuel is supplied and stored in a thermally insulated tank at a cryogenic temperature.

The technical result achieved by the present invention is especially important when using low-boiling fuels, such as natural gas and hydrogen: it becomes possible to refuel the engine with gaseous fuels at normal temperature, reduce the cost of liquefaction, delivery and storage of cryogenic fuels at gas stations, the system is simplified and localized on the engine supply of cryogenic fuel, which increases reliability and simplifies engine operation.

The invention is illustrated by examples.

Example 1. The engine of a truck operating on liquid propane-butane contains a fuel supply system including a thermally insulated tank with a capacity of 80 kg of fuel, refueling, consumable, safety valves, a heat accumulator, a filter, a mixer, and a gas reducer. The fuel volume in the tank is 130 liters. The average heat capacity of propane-butane is 0.52 cal / g · deg. Nickel with an average heat capacity in the range of operating temperatures from 225K to 298K, comprising 0.102 cal / g · deg, was adopted as the material of the battery nozzle. To transfer the cold resource from the fuel to the heat accumulator nozzle, a nozzle mass of 408 kg is required. The volume of the battery nozzle is 46 liters. When using aluminum nozzles with a heat capacity of 0.206 cal / g · deg, the mass of the nozzle is 202 kg and the volume is 74 l.

The propulsion system operates as follows.

At the first refueling, 130 l of propane-butane at a temperature of 225K are poured into the heat-insulated tank through its neck from the refueling tank.

When the engine is running, low pressure nitrogen is supplied to the tank, which displaces the liquid fuel from the tank into the battery, where the fuel is evaporated and heated to the nozzle temperature at the battery outlet. Next, the fuel is passed through a filter, mixed in the mixer with air and, by adjusting the flow rate of the mixture with a gas reducer, is fed to the engine. As a result of heat exchange, the battery nozzle cools and by the end of the liquid fuel supply takes its temperature. After engine operation, the fuel line is shut off to prevent warm air from entering the system. At the second and subsequent refueling, fuel is supplied to the tank from the gas-balloon refueling system. At the same time, fuel at normal temperature is first passed through the nozzle of the battery, condensing the gas and heating the nozzle to normal temperature. Due to heat losses, the volume of subsequent refueling decreases slightly each time. After refueling, before starting the engine, the fuel tank is separated by a valve from the heat accumulator.

Example 2. The engine of a truck operating on liquefied natural gas contains a fuel supply system similar to that described in Example 1. The fuel volume in the tank is 190 l. The average heat capacity of liquid natural gas is 0.82 cal / g · deg. As the material of the battery nozzle, aluminum with an average heat capacity in the range of operating temperatures from 109K to 298K, comprising 0.168 cal / g · deg, was adopted. To transfer the cold resource from the fuel to the heat accumulator nozzle, a nozzle mass of 390 kg with a volume of 145 liters will be required. When using a nozzle made of fluoroplast-4 with a heat capacity of 0.185 cal / g, deg, the mass of the nozzle will be 355 kg, and the volume will be 150 l.

The propulsion system works similarly to that described in Example 1. At the first refueling, 190 l of liquefied natural gas at a temperature of 109K are poured into the heat-insulated tank through its neck from the refueling tank. At the second and subsequent refueling, natural gas is supplied to the tank from the gas network of the gas station. In this case, fuel at normal temperature is first passed through the nozzle of the battery, condensing the gas and heating the nozzle to normal temperature. After refueling, before starting the engine, the fuel tank is separated by a valve from the heat accumulator.

Example 3. An engine of a city bus operating on liquid hydrogen contains a fuel supply system similar to that described in Example 1. Given the high calorific value of hydrogen, the fuel supply in the tank is assumed to be 40 kg. The fuel volume in the tank is 570 liters. The average heat capacity of liquid hydrogen is 2.33 cal / g · deg. Fluoroplast-4 with an average heat capacity in the range of operating temperatures from 20K to 298K of 0.144 cal / g · deg was used as the material of the battery nozzle. To transfer the cold resource from the fuel to the nozzle of the heat accumulator, the mass of the nozzle is 650 kg with a volume of 270 liters.

The propulsion system operates similarly to that described in Example 1. At the first refueling, 570 l of liquid hydrogen at a temperature of 20K is poured into the heat-insulated tank through its neck. When the engine is running, low pressure helium is supplied to the tank for boosting it from a helium cylinder. At the second and subsequent refueling, hydrogen is supplied to the tank from the gas-balloon system of the gas station. In this case, fuel at normal temperature is first passed through the nozzle of the battery, condensing the gas and heating the nozzle to normal temperature. After refueling, before starting the engine, the fuel tank is separated by a valve from the heat accumulator.

Claims (1)

A method of supplying an internal combustion engine with cryogenic fuel, in which cryogenic fuel is supplied and stored in a heat-insulated tank in a liquid state at a cryogenic temperature during refueling, while the engine is running, cryogenic fuel is fed into a heat accumulator, heated in it to a gaseous state, mixed with air and fed into a combustion chamber of an engine, characterized in that during the first refueling, cryogenic fuel is supplied and stored in a thermally insulated tank, while the engine is operating when the cryogenic fuel is heated to heat ohm the battery is cooled and stored the nozzle of the battery at a cryogenic temperature, and at subsequent refills, cryogenic fuel in a gaseous state at normal temperature is supplied to a heat accumulator and cooled in it to a cryogenic temperature, while the battery nozzle is heated and stored at normal temperature, and cryogenic fuel is fed and stored in a thermally insulated tank at a cryogenic temperature.