ES2657082A1 - GAS ENERGY RECOVERY EQUIPMENT FROM THE COMBUSTION (Machine-translation by Google Translate, not legally binding) - Google Patents

Abstract

Equipment for the recovery of energy from combustion gases. The invention describes a device for recovering the energy of gases coming from combustion in an internal combustion engine. The internal combustion engine comprises a motor block and a post-treatment system for gases coming from combustion. The energy recovery equipment is disposed downstream of the post-treatment system and comprises a first turbogroup consisting of a first turbine and a first compressor to recover energy from the gases evacuated to the atmosphere; an ejector to recover energy from recirculated gases; and an additional compressor. In this way, the pressure of the intake gases to the combustion engine is increased by taking advantage of the energy from the combustion gases both evacuated to the atmosphere and recirculated. (Machine-translation by Google Translate, not legally binding)

Description

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The engine block (1) may have any suitable and displacement number of cylinders capable of operating in low temperature combustion mode (LTC), in particular of the RCCI type. This type of combustion is especially demanding from the point of view of compliance with pollutant emissions regulations since it can lead to a high rate of formation of CO and HC combined with gases from low temperature combustion in order to optimize consumption specific.

The post-treatment system (2) for combustion gases is located just after the engine block (1), upstream of a turbine (4) (pre-turbine location) which will be described later. In this location, the temperature of the gases from combustion is maximum. The post-treatment system (2) comprises at least the functions of filtering particulate material and oxidation of CO and HC. This allows to always work with soot-free recirculated gases and guarantees that the chemical energy released in the oxidation of unburned hydrocarbons is used in the elements located downstream of said post-treatment system (2), in the form of both thermal energy as mechanical according to the process carried out, and both for the recirculated gases and for the gases from the combustion of the engine that will be evacuated to the atmosphere.

According to alternative embodiments of the present invention, other post-treatment systems are also provided for the reduction of NOx emissions, as is known to those skilled in the art. Also, the architecture of this post-treatment system (2) is not particularly limited, and any of the many possibilities known in the prior art can be used. For example, the use of a diesel oxidation catalyst (DOC) can be used together with a filter

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(8)

of the second turbogroup (9). This second turbine (8) is of variable geometry to allow regulating the cost of recirculated gases. The expansion of the recirculated gases allows to obtain mechanical energy to drive to the second compressor

(10)

of the second turbogroup (9) in which the fresh air pressure admitted by the engine is increased. The recirculated gases are then directed to an ejector (7) of fixed geometry in which they expand resulting in their cooling and the increase of fresh air pressure, coming from the second compressor (10), with which they are mixed. With this configuration, the flow of recirculated gases is regulated by the position of the second turbine (8) of variable geometry. This avoids the direct strangulation of the flow of recirculated gases in the intake line, which reduces the pumping work and avoids the penalization of consumption.

From the ejector (7) the mixture of fresh air and recirculated gases is conducted to a condensate separator

(2. 3)

 which protects the impact of condensed liquids on the impeller of the first compressor (20) of the first turbogroup (5) located below. This first compressor (20) increases the pressure of the mixed flow, in what is a third stage of compression, when driven by the mechanical work provided by the expansion of the gases evacuated to the atmosphere in the first turbine (4) of the first turbogroup (5), which can be of fixed geometry (instead of variable geometry) due to the high expansion ratio with which it will work.

This configuration allows small turbines to be available since each of them will move approximately half of the flow of gases from combustion (high rate of recirculated gases in RCCI combustion systems) while the series compressors will also be sized reduced. The second compressor (10)

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Claims (1)

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