JPH0281933A - Carbon dioxide treating device for closed circuit diesel engine - Google Patents

Abstract

PURPOSE:To enable a stable driving of a diesel engine without changing the volume and flow rate of an unwashed working fluid by providing a blower and an intercooler on the upper stream side of a carbon dioxide sucking device, and to enable the temperature control of the working fluid after washed with the cooling water of the diesel engine by providing a heat exchanger for gas temperature control just in the front of an intake port of the diesel engine. CONSTITUTION:An unwashed working fluid A leaving a blower 6 and an intercooler 4a is introduced into a carbon dioxide sucking device 13. The volume and flow rate of the unwashed working fluid within the carbon dioxide sucking device is made constant even when the load of a diesel engine is changed, and the diesel engine can be stably run. Further, as a heat exchanger for gas temperature control 50 controlled by the cooling water of the diesel engine is provided just in the front of an intake port 1B of the diesel engine, an excessive reduction in temperature of the working fluid after washing is prevented, and the combustion performance of the engine can be maintained satisfactorily.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a closed-circuit diesel engine that is mainly used for underwater navigation and the like and therefore needs to be made compact as a whole.

[Conventional technology]

In a closed circuit diesel engine, after cooling the working fluid, which is the exhaust gas, oxygen is supplied,
However, combustion of the fuel increases carbon dioxide gas in the working fluid, making combustion difficult for the engine.

Therefore, some or all of the uncleaned working fluid containing carbon dioxide gas is absorbed into an absorption liquid for absorbing carbon dioxide gas in an absorption tower, and only the components of the working fluid, such as nitrogen, are returned to the intake side. It is recycled and reused as a working fluid.

In that case, the rich absorption liquid that has absorbed carbon dioxide gas is heated to release the absorbed carbon dioxide gas and discharged to the outside of the system, and the lean absorption liquid that has released carbon dioxide gas absorbs carbon dioxide gas. It is sent to an absorption tower for reuse.

The above carbon dioxide absorption liquid is stored in the regeneration tower for a certain period of time.
It is known that the regeneration rate is better when kept at a high temperature, and a tall regeneration tower is generally required, especially for the carbon dioxide treatment equipment of this type of diesel engine used for underwater navigation. There is a problem that it goes against the idea of compactness.

Further, in the above-mentioned conventional apparatus, a high-blue absorption tower is used to spray a lean absorption liquid into the working fluid, which is exhaust gas, and such an absorption tower also becomes an obstacle to miniaturization.

Furthermore, in conventional equipment, a mist of a lean absorption liquid for carbon dioxide absorption is sprayed onto the unwashed working fluid in the absorption tower using a nozzle, and downstream, the absorption liquid mist is separated and collected from the working fluid to create a rich absorption stream. Conventionally, when sending the liquid as a liquid to the regeneration tower, a filter has conventionally been used in the mist separation section.

However, filters inherently have a weak self-cleaning ability, and although they can easily remove large mist particles, including droplets, a large differential pressure must be applied to the filter to remove small mist particles. However, in order to improve the mist removal efficiency, there is a problem in that the equipment cost and maintenance cost of the filter increase.

Therefore, in the carbon dioxide treatment equipment for the unwashed working fluid of a closed circuit diesel engine, we did not use the conventionally required towers and tanks such as regeneration towers and absorption towers, making the entire equipment more compact, and making the rich carbon dioxide gas treatment equipment more compact. The absorption liquid is heated with lean absorption liquid, engine lubricating oil, and uncleaned working fluid from the engine to increase the degree of regeneration of the absorption liquid, and then the unwashed working fluid is sprayed with a mist of IJ-lean absorption liquid. A carbon dioxide treatment device for a closed-circuit diesel engine has been devised, as shown in the system diagram in Figure 2, which separates the working fluid after cleaning and the carbon dioxide-rich absorption liquid easily and with high removal efficiency. The outline will be explained below.

That is, the exhaust gas discharged from the exhaust port IA of the closed-circuit diesel engine I drives the turbine 2 of the supercharger as an unwashed working fluid shown by arrow A, and then passes through the carbon dioxide absorption liquid regeneration device I7. , passes through an exhaust cooling device 14 that sprays cooling water W and a centrifugal separator 5, and enters the carbon dioxide absorption device 13, where a lean absorption liquid for carbon dioxide absorption is sprayed by a nozzle 19, and then this carbon dioxide absorption A centrifugal separator 22 provided on the outlet side of the device 13 separates the washed working fluid J into a rich absorption liquid that has absorbed carbon dioxide gas.

The above-mentioned cleaning working fluid J is supplied with oxygen gas 02 from the oxygen supply pipe 7, and is pressurized by the blower 6 of the supercharger.
After being cooled by the cooling water W in the intercooler 4a, the fuel F is supplied to the intake port IB of the diesel engine 1, and the fuel F is supplied to the combustion chamber of the diesel engine 1 from the fuel supply pipe 8. The engine 1 is provided with an engine cooling water passage 9 through which cooling water circulates.

Further, the lubricating oil of this diesel engine 1 passes through a lubricating oil flow path shown by arrow C and heats a rich absorption liquid that is sent to a carbon dioxide absorption liquid regeneration device 17 by a heat exchanger 11.

Next, the rich absorption liquid separated by the centrifugal separator 22 is given heat by exchanging heat with the lean absorption liquid in the heat exchanger 3, and is further heated by the heat exchanger 11. Thereafter, it is introduced into a carbon dioxide absorption liquid regeneration device 17, and after releasing carbon dioxide gas, it is discharged as a lean absorption liquid. In addition, in the figure, the reference numeral 20 indicates a pump.

The carbon dioxide treatment equipment described above does not use towers and tanks such as regeneration towers and absorption towers as in the past, so the entire structure can be made compact, and the rich absorption liquid containing carbon dioxide gas can be stored in a lean manner. After being heated by the absorption liquid and the engine's lubricating oil, carbon dioxide gas is released while being heated by the unwashed working fluid, increasing the degree of regeneration of the absorption liquid.
Furthermore, the unwashed working fluid sprayed with a mist of lean absorption liquid can be easily and efficiently separated into the washed working fluid and the carbon dioxide rich absorption liquid using a centrifugal separator. This has the advantage that smooth engine operation can be maintained.

However, in the carbon dioxide treatment device devised above, the pressure of the unwashed working fluid A in the carbon dioxide absorption device 13 is always maintained close to atmospheric pressure, so when the load of the diesel engine 1 changes, Accordingly, the flow rate of the unwashed working fluid A within the carbon dioxide absorption device 13 changes.

This means that the contact time between the lean absorption liquid that absorbs carbon dioxide gas and the unwashed working fluid A changes significantly depending on the main engine load, and that Changes will also occur in the efficiency of gas-liquid separation, and these changes will become a problem when the diesel engine 1 is under high load.

[Purpose of the invention]

The present invention has been made in order to solve the problems in the carbon dioxide treatment equipment described above, and even if the load of the main engine, the diesel engine, changes, the flow rate of the unwashed working fluid remains the same as that of the absorbing liquid. The object of the present invention is to provide a carbon dioxide treatment device for a closed-circuit diesel engine that can maintain stable operation by keeping the contact time with the cleaning working fluid almost constant.

[Summary of the invention]

In order to achieve the above object, the carbon dioxide treatment device for a closed circuit diesel engine of the present invention uses a rich absorption liquid that has absorbed carbon dioxide from an unwashed working fluid, which is exhaust gas from the diesel engine, to the diesel engine. A carbon dioxide absorption liquid regeneration device that regenerates the lean absorption liquid by heating it with lubricating oil and then releasing carbon dioxide gas while heating it with the unwashed working fluid, and the lean absorption liquid sent from the device. A carbon dioxide absorption device that flushes into the unwashed working fluid via the blower of the turbocharger of the diesel engine and the intercooler downstream thereof after exchanging heat with the rich absorption liquid, and the exit side of the device. The diesel engine is equipped with a centrifugal separator that separates the washed working fluid, which is sent to the intake port of the diesel engine via a heat exchanger for gas temperature adjustment, and a rich absorption liquid.

The carbon dioxide treatment device with the above configuration has almost the same functions as the conventional device, but by providing the blower and intercooler upstream of the carbon dioxide absorption device, the main engine, the diesel engine, Even if the load changes, the volume and flow rate of the uncleaned working fluid in the carbon dioxide absorption device do not change, and stable operation is performed.

In addition, when oxygen is supplied from the oxygen supply pipe to the working fluid after cleaning, in a closed circuit diesel engine, the oxygen is supplied as evaporated liquid oxygen, so the temperature is usually below 0°C. A heat exchanger for gas temperature adjustment is installed just before the intake port, and the temperature is adjusted using cooling water from the diesel engine.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the carbon dioxide treatment apparatus of the present invention will be described below with reference to the drawings and the system diagram shown in FIG.

First, like the conventional device shown in Fig. 2, this carbon dioxide treatment device is installed in a closed-circuit diesel engine mainly used for underwater navigation, etc.
It has almost the same configuration and function as the conventional example shown in Fig. 2, and the same parts are indicated by the same part numbers in Figs. 1 and 2, and its flow is also similar to the conventional example shown in Fig. 2. Duplicate explanations will be omitted, and differences from FIG. 2 will be mainly explained.

Therefore, in the carbon dioxide treatment device of the present invention, the blower 6 rotated by the turbine 2 of the supercharger of the diesel engine 1
And the unwashed working fluid A exiting the intercooler 4a downstream thereof is introduced into the carbon dioxide absorption device 13, where a lean absorption liquid for carbon dioxide absorption is sprayed by the nozzle 19,
The washed working fluid discharged from the carbon dioxide absorption device 13 is separated by a centrifugal separator 22 into a washed working fluid J and a rich absorption liquid that has absorbed carbon dioxide gas.

Next, immediately before the intake port IB of the diesel engine 1, a gas temperature adjustment heat exchanger 50 whose temperature is adjusted by the cooling water of the diesel engine 1, that is, hot water, is installed in the flow path of the cleaned working fluid J. There is.

The temperature is adjusted in this way because the oxygen added from the oxygen supply pipe 7 is evaporated from liquid oxygen;
This is because the temperature is at a low temperature of .degree.

〔Effect of the invention〕

As explained above, the carbon dioxide treatment device for a closed circuit diesel engine of the present invention does not use towers and tanks such as conventional regeneration towers and absorption towers, so it has the advantage that the entire device can be made compact. In particular, the present invention can be effectively applied to diesel engines and the like used as underwater power sources.

In addition, by effectively using the lean absorption liquid, the lubricating oil of the diesel engine, and the unwashed working fluid that is the exhaust gas as a heat source for regenerating the rich absorption liquid containing carbon dioxide, we can generate energy that is emitted from the diesel engine. This has the advantage that it is possible to make more effective use of carbon dioxide, and to circulate more of the sufficiently regenerated lean absorption liquid, thereby improving the performance of absorbing and removing carbon dioxide gas.

Furthermore, in the device of the present invention, the unwashed working fluid that has been sprayed with a lean absorption liquid in the carbon dioxide absorption device can be efficiently and easily removed by using a centrifugal separator to convert the unwashed working fluid into a washed working fluid and a rich absorption liquid. As a result, it has the effect of increasing the recovery rate of the absorbent, and moreover, the absorbent can be separated advantageously with lower equipment costs and running costs than conventional filters.

In particular, in the carbon dioxide treatment device of the present invention, the volumetric flow rate of the unwashed working fluid in the carbon dioxide absorption device is constant even when the load of the main diesel engine changes, and the lean absorption for carbon dioxide gas absorption is achieved. The contact time between the liquid and the unwashed working fluid is also kept almost constant regardless of the load on the main engine, which provides the advantage of stable operation of this closed-circuit diesel engine.

In addition, by installing a gas temperature adjustment heat exchanger just before the intake port of the diesel engine of the main engine, the temperature can be increased by adding oxygen gas, which is obtained by evaporating liquid oxygen in the working fluid after cleaning, to the intake side of the main engine. Another advantage is that it prevents the fuel from dropping too low and maintains good engine combustion performance.

[Brief explanation of the drawing]

FIG. 1 is a system diagram of a carbon dioxide treatment device for a closed circuit diesel engine according to an embodiment of the present invention, and FIG. 2 is a system diagram of a conventional carbon dioxide treatment device. ■...Diesel engine, IB...Intake port, 3...
Heat exchanger, 4a... intertellar, 6... blower 11... heat exchanger, 13... carbon dioxide absorption device,
17... Carbon dioxide absorption liquid regeneration device, 22... Centrifugal separator, 50... Heat exchanger for gas temperature adjustment, A... Unwashed working fluid, C... Lubricating oil path, J. ...Working fluid after cleaning.

Claims (1)

[Claims] A rich absorption liquid that absorbs carbon dioxide in an unwashed working fluid from a closed-circuit diesel engine is heated with the lubricating oil of the diesel engine, and then carbon dioxide is released while being heated with the unwashed working fluid. A carbon dioxide absorption liquid regeneration device regenerates into a lean absorption liquid, and after the lean absorption liquid sent from the device undergoes heat exchange with the rich absorption liquid, the blower of the turbocharger of the diesel engine and its downstream A carbon dioxide absorption device that flushes into unwashed working fluid that has passed through an intercooler, and a cleaned working fluid that is provided at the outlet side of the device and sent to the intake port of the diesel engine via a gas temperature adjustment heat exchanger. A carbon dioxide treatment device for a closed-circuit diesel engine that consists of a centrifugal separator that separates carbon dioxide from a rich absorption liquid.