JPH0336151B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a waste heat recovery device for an internal combustion engine that evaporates the cooling water itself and effectively utilizes it as steam without boiling the cooling water that has absorbed the waste heat of the internal combustion engine.

When an internal combustion engine is operated, waste heat is released into the exhaust gas and cooling water, and one of the current challenges is how to utilize this effectively.

Among these, the temperature of the exhaust gas is high, so it is easy to obtain steam using a waste heat boiler. However, although the most common form of cooling water is heat utilization as hot water, unlike steam, the uses of hot water are narrow. On the other hand, there are the following known methods for obtaining and utilizing steam from cooling water, but each method has its own drawbacks.

One type of boiling cooling method is to boil water in the cylinder jacket of an internal combustion engine and take it out of the engine as a brackish water mixture to separate the brackish water. However, if the control method is poor, the engine may overheat and burn out. There is a danger of inviting Another pressurized water-cooled heat exchange system uses a closed pressurized internal combustion engine cooling water system to raise the water temperature without boiling it, and then exchanges heat with make-up water in a separate system to evaporate the make-up water. However, this method has disadvantages such as temperature differences occurring in the heat exchanger and high equipment costs.

The present invention has been made in view of the above-mentioned drawbacks, and an object of the present invention is to propose a waste heat recovery device for an internal combustion engine that does not allow boiling in the engine and that generates steam from cooling water without a heat exchanger. .

Next, one embodiment of the present invention will be described with reference to the drawings.
The figure is a configuration diagram of an embodiment, where 1 is a cooling water circulation pump, 2 is an internal combustion engine, and 21 is a circulation pump 1.
The pressurized cooling water 22 inputted under pressure is high-temperature cooling water that has absorbed waste heat from the internal combustion engine. 31 and 32 are pressure controllers and regulating valves for keeping the inside of the engine jacket in a pressurized state to prevent water from boiling. 5 is a flash tank into which high-temperature cooling water 22 is introduced and separated into steam and water; 51 is an internal water droplet separator; 52 is water; and 6 is steam obtained by flashing. Reference numerals 71 and 72 are water level control devices and regulating valves in the flush tank, which adjust the make-up water 9 supplied by the make-up cooling water pump 8. Furthermore, 101 is a temperature detector;
2 is a relief valve controlled by the detector,
Note that 103 is an aperture.

Next, the operation of this embodiment will be explained. In the figure, cooling water 21 pressurized by the circulation pump 1
absorbs waste heat after cooling the internal combustion engine 2, becomes high-temperature cooling water 22, and is sent to the flash tank 5. At this time, the inside of the jacket of the internal combustion engine is kept under pressure to prevent the cooling water from boiling. A pressure controller 31 controls a regulating valve 32 . Since the internal pressure in the flash tank 5 is lower than the primary side pressure of the regulating valve 32, the high-temperature cooling water 22 flows into the flash tank 5 and simultaneously flashes and separates into steam and water droplets, and the steam 6 flows through the steam pipe. After that, it is sent to the end of use. On the other hand, the separated water droplets are combined with make-up water 9 sent through make-up water pump 8 and adjustment valve 72 controlled by water level control device 71, and sent to internal combustion engine 2 again by circulation pump 1. The regulating valve 32
is high temperature cooling water 2 to prevent boiling inside the jacket.
2 to maintain the pressure inside the jacket, but in the unlikely event that this malfunctions, the water will drip and the internal combustion engine 2 will be damaged.
In order to prevent the water from burning out, a temperature detector 101 is activated when the water temperature inside the jacket rises too much, and a relief valve 102 is opened in response to a command from the temperature detector 101 to ensure water flow even in an emergency. However, if the flow rate is too large, there is a problem that the water in the internal combustion engine 2 will boil all at once, so the flow rate of the cooling water is restricted by the throttle 103. Of course, it would be even more useful if a known method for recovering heat from the exhaust gas by passing the exhaust gas from the internal combustion engine 2 through a heat exchanger (not shown) provided in the flash tank 5 is used in combination.

As explained above, the present invention provides a waste heat recovery internal combustion engine with a circulation pump for pressurizing cooling water provided on the engine inlet side, a regulating valve for high-temperature cooling water provided on the engine outlet side, and a circulating pump for pressurizing cooling water provided on the engine outlet side. A flush tank has an internal pressure lower than the internal pressure on the inlet side of the valve, separates moisture and steam from high temperature cooling water introduced through the regulating valve to obtain steam, and supplies water to the circulation pump. This waste heat recovery device for an internal combustion engine is equipped with a relief valve with a flow rate restriction that operates when the engine temperature rises between the engine outlet and the cooling water supply path to the engine, so that the cooling water is not released inside the jacket of the internal combustion engine. By evaporating the cooling water itself without boiling it, you can easily obtain steam with high energy utilization.
It has excellent features that effectively save energy.

[Brief explanation of the drawing]

The figure is a configuration diagram showing an embodiment of the present invention. 1 is a circulation pump, 2 is an internal combustion engine, 21 is pressurized cooling water, 22 is high temperature cooling water, 31 is a pressure controller, 3
2 is a regulating valve, 5 is a flush tank, 51 is a water droplet separator, 52 is water, 6 is steam, 71 is a water level control device, 72 is a regulating valve, 8 is a supplementary cooling water pump, and 9 is supplementary water.

Claims (1)

[Claims] 1. In a waste heat recovery internal combustion engine, there is a circulation pump for pressurizing cooling water provided on the engine inlet side, a regulating valve for high-temperature cooling water provided on the engine outlet side, and a pressure lower than the internal pressure on the inlet side of this regulating valve. A flush tank is provided, which has an internal pressure, separates moisture and steam from the high-temperature cooling water introduced through the regulating valve to obtain steam, and supplies water to the circulation pump, and is connected to the engine outlet. A waste heat recovery device for an internal combustion engine, characterized in that a relief valve with a flow rate restriction that is activated when the engine temperature rises is provided between a cooling water supply path to the engine.