JPS6183448A - Condenser for evaporative cooling type engine - Google Patents

Abstract

PURPOSE:To reduce a pressure loss as well as to improve cooling efficiency ever so better, by forming an upper end of a refrigerant tube interconnecting both upper and lower tanks of a condenser into a nonprojection state to an empty space inside the upper tank. CONSTITUTION:An upper tank 31 and a lower tank 32 of a condenser 3 are interconnected with each other through a refrigerant tube 38. An upper end 38a of this refrigerant tube 38 is inserted into a boss part 34a of a seat plate 34 constituting a bottom wall part of the upper tank 31 and joined together, and projected more upward than the boss part 34a, but a guide plate 40 is set up on top of the seat plate 34 so as to cover this projection part. With this guide plate 40, the upper end 38a of the refrigerant tube 38 is formed into a nonprojection state to an empty space inside the upper tank 31 whereby inflow of steam from the inside of the upper tank to the refrigerant tube becomes smoothed, thus a pressure loss is reducible.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a boiling-cooled engine that stores liquid-phase refrigerant up to a predetermined level in a water jacket and performs efficient cooling by boiling and vaporizing the liquid-phase refrigerant. , relates to a condenser used for condensing generated vapor (vapor phase refrigerant).

<Prior Art> As an engine cooling device, a boiling cooling device that utilizes the boiling and condensing cycle of a refrigerant (cooling water) has been proposed in place of the conventional water-cooled cooling device, for example, in Japanese Patent Application Laid-Open No. 57-62912. This has been proposed, and the present applicant has already filed various applications (Japanese Patent Application No. 145470/1982, etc.). Basically, liquid refrigerant is stored up to a predetermined level in a water jacket formed between the cylinder block and cylinder head, and the liquid refrigerant is boiled and vaporized to cool each part. The vapor is taken out from the top of the water jacket, guided to an external condenser, where it is condensed and liquefied, and then circulated back into the water jacket.

By the way, the condenser for condensing the vapor phase refrigerant in this type of boiling cooling system basically has the same structure as the radiator of the conventional water-cooled cooling system. (Refer to page 44 of “Class 2 Automobile Gasoline Engine” published by the Japan Automobile Maintenance Promotion Association on 20th)
It was as shown in the figure below. In the figure, 51 is an upper tank, 52 is a seat plate, 53 is a refrigerant tube in the core, and 54 is a cooling fin in the core.

<Problems to be Solved by the Invention> However, in such conventional condensers, the upper ends of the refrigerant tubes 53 protrude above the seat plate 52 forming the bottom wall of the upper tank 51, which causes problems in water-cooled engines. When used as a radiator, there is no problem because the flow rate is slow, but in a boil-cooled engine, the steam flow rate is fast, so when the steam that flows into the upper tank 51 branches into a large number of refrigerant tubes 53, as shown in FIG. This tends to generate eddy currents, which causes pressure loss, which makes it easier for steam generated in the water jacket to stay in the water jacket, reducing cooling efficiency and reducing the efficiency of the refrigerant circulation pump. There was a problem that the response rate of the control was deteriorated, and the responsiveness of the control was also deteriorated.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a condenser having a structure suitable for a boiling-cooled engine that can reduce pressure loss when refrigerant vapor branches from an upper tank to a large number of refrigerant tubes.

Means for Solving the Problems In order to achieve the above object, the condenser for a boiling-cooled engine according to the present invention includes an upper upper tank having a vapor inlet, a lower lower tank having a liquefied refrigerant outlet,
and a core section consisting of a plurality of vertical refrigerant tubes that communicate with both tanks, and the upper end of the refrigerant tube connected to the bottom wall of the upper tank does not protrude into the space within the upper tank. is formed.

Therefore, the steam that has flowed into the upper tank flows into the refrigerant tube in a rectified state without creating a vortex or the like, and pressure loss therein can be reduced.

<Example> The present invention will be explained in detail below.

1 to 3 show one embodiment of the capacitor according to the present invention, and FIG. 4, furthermore, FIGS. 5 and 6 show other embodiments. An example of a cooling system for a boiling-cooled engine using a condenser will be described.

In FIG. 7, 1 is an engine equipped with a water jacket 2, 3 is a condenser for condensing vapor phase refrigerant, and 4 is an electric refrigerant supply pump.

The water jacket 2 is formed over both the cylinder pro/liquid 5 and the cylinder head 6 so as to surround the outer periphery of the cylinder and combustion chamber of the engine 1. A ratio is provided. This lower vapor ratio is connected to an upper tank 31 (described later) of the condenser 3 via a connecting pipe 8 and a steam passage 9, and the connecting pipe 8 has a discharge pipe attachment part 10 which is the top of the refrigerant circulation system. is formed in an upwardly erected shape, and its upper end opening is sealed by a cap 1).

The condenser 3 is installed at a position such as the front of the vehicle where it receives wind from the vehicle, and is further provided with an electric cooling fan 12 for forced cooling on the front or back side thereof. A refrigerant circulation passage 13 is connected to a lower tank 32 (described later) of this condenser 3 at a relatively lower portion thereof, and this refrigerant circulation passage 13 is connected to the refrigerant circulation passage 13 via a second electromagnetic valve 21 (described later) and the refrigerant supply pump 4. It is connected to the refrigerant port 14 of the water jacket 2.

A refrigerant circulation system is constituted by the above-mentioned path from water jacket 2 to condenser 3 to refrigerant supply pump 4 to water jacket 2.

Next, reference numeral 15 indicates a reservoir tank, which is provided outside the circulation system to store a preliminary liquid phase refrigerant, and is opened to the atmosphere through a cap 16 having a ventilation function. At the same time, it is installed at a relatively high location in the vehicle so that the liquid level can be secured at a higher position than the uppermost end of the circulation system, that is, the discharge pipe mounting portion 10 of the connecting pipe 8. An air exhaust passage 18 is connected to the exhaust pipe attachment part 10 via a first solenoid valve 17 in order to exhaust the air in the system, and at the same time collects the liquid phase refrigerant that overflows when the air is exhausted. In order to do this, the distal end of the air exhaust passage 18 is inserted into the reservoir tank 15 and opens at a relatively upper portion thereof.

Furthermore, a first auxiliary refrigerant passage 19 and a second auxiliary refrigerant passage 20 are connected to the bottom of the reservoir tank 15 . The first auxiliary refrigerant passage 19 is connected to the upstream side (suction side) of the refrigerant supply pump 4 of the refrigerant circulation passage 13 via a second electromagnetic valve 21 that is a three-way valve. Said second auxiliary refrigerant passage 2
0 is connected to a relatively upper portion of the lower tank 32 via the third solenoid valve 22.

Each of the above solenoid valves 17.21.22. The refrigerant supply pump 4 and the cooling fan 12 are driven and controlled by a control device 23 using a microcomputer. The second liquid level sensor 2 provided
6 and a negative pressure switch 27 provided at the top of the circulation system, control described later is performed based on detection signals from the negative pressure switch 27 provided at the top of the circulation system.

That is, at the start of operation, the first solenoid valve 17 is opened, the second solenoid valve 21 is in the flow path A, and the third solenoid valve 22 is closed, so that the refrigerant supply pump 4 is driven for a certain period of time, and the refrigerant reservoir tank 1 outside the system is driven.
5 into the system through the first auxiliary refrigerant passage 19, and the air in the system is discharged through the air discharge passage 18 to the reservoir tank 15 outside the system. Once the water is full, the first solenoid valve 17 is closed, the second solenoid valve 21 is in the flow path B, and the third solenoid valve 22 is opened, so that the steam generated due to the start of boiling inside the water jacket 2 Using the pressure, surplus liquid phase refrigerant in the system is discharged through the second auxiliary refrigerant passage 20 to the outside of the system to the liquid level sensor 15, and at this time, the third liquid level refrigerant is The liquid level inside the water jacket 2 and the lower tank 32 are controlled by controlling the opening and closing of the solenoid valve 22 and the ON/OFF control of the refrigerant supply pump 4.
The internal liquid level is set to a predetermined level, and the amount of liquid medium sealed in the system is defined.

During normal operation thereafter, the first solenoid valve 17 is closed, the second solenoid valve 21 is closed, and the third solenoid valve 22 is closed, so that the circulation system is in a closed state, and in this state, the water jacket 2 is closed. The engine 1 is cooled by boiling and vaporizing the liquid phase refrigerant. The generated steam is then sent to the condenser 3, where it is condensed and liquefied by forced cooling air from a cooling fan 12 that operates based on the traveling air and a signal from the temperature sensor 25.

The liquefied refrigerant is temporarily stored in the lower tank 32 at the bottom of the condenser 3, and from there it is sent to the first and second liquid level sensors 2.
By operating the refrigerant supply pump 4 based on the 4°26 signal, the refrigerant is circulated and supplied so as to keep the liquid level in the water jacket 2 constant. At the same time, excess or deficiency of the refrigerant is monitored, and based on the signal from the negative pressure switch 27, the negative pressure state within the system is monitored, and refrigerant shortage avoidance, excess refrigerant avoidance, and negative pressure prevention control are performed. , the details of the control are in the patent application 1986-100.
It is described in No. 157, etc.

As shown in FIGS. 1 to 3, the capacitor 3 according to the present invention includes an upper tank 31 on the upper side and a lower tank 3 on the lower side.
2 and a core portion 33 between the two.

The upper tank 31 and lower tank 32 are made of metal such as copper or aluminum, or resin, and the bottom wall of the upper tank 31 and the upper wall of the lower tank 32 are formed by separate metal seat plates 34 and 35. . A steam inlet 36 to which the steam passage 9 is connected is provided on the side surface of one end of the upper tank 31 and near the earthen wall.
A liquefied refrigerant outlet 37 to which the refrigerant circulation passage 13 is connected is provided on the side surface of one end of the lower tank 32 located approximately diagonally therefrom. When applied to the system shown in FIG. 7, it goes without saying that the port tank 32 is further provided with a connection port for the second auxiliary refrigerant passage 20 and a mounting port for the second liquid level sensor 26.

The core portion 33 includes a large number of flat refrigerant tubes 38 made of a metal with good thermal conductivity such as copper or aluminum along the vertical direction, and a corrugate type or plate type provided between the refrigerant tubes 38. cooling fin 3
The refrigerant tubes 38 are connected to the upper tank 31 and the lower tank 32 at their upper and lower ends, respectively, and the refrigerant tubes 38 communicate with each other.

Here, the upper end 38a of the refrigerant tube 38 is connected to the boss portion 34a of the seat plate 34 that constitutes the bottom wall portion of the upper tank 31.
is inserted into the boss portion 34 and joined by brazing.
A guide plate 40 is arranged on the seat plate 34 so as to cover this protrusion. This guide plate 40 has fitting holes 40a at predetermined intervals as shown in FIG. 3, and the lower part of each fitting hole 40a is fitted into the upper end 38a of the refrigerant tube 38. In addition, each fitting hole 40
A cutout is also provided in the lower part of a to allow the boss portion 34a to escape. Further, the upper portion of each fitting hole 408, that is, the portion above the end surface of the refrigerant tube 38 is expanded into a bell mouth shape. The guide plate 40 is prevented from coming off by a presser 41 fixed to the inner surface of the upper tank 31 and having a cross-sectional shape. Incidentally, instead of this presser 41, as shown in FIG.
It is also possible to form a.

In the condenser 3 configured as described above, refrigerant vapor flows from the vapor inlet 36 of the upper tank 31, is cooled and condensed while passing through each refrigerant tube 38, is collected in the lower tank 32, and then is liquefied at the refrigerant outlet. However, since the upper end 38a of each refrigerant tube 38 is formed in a non-protruding state with respect to the space inside the upper tank 31 by the guide plate 40, vapor from inside the upper tank 31 to each refrigerant tube 38 is extracted from the upper tank 31 as a liquid phase refrigerant. The flow of water becomes smooth and the pressure loss here can be reduced.

In addition, it is only necessary to arrange the guide plate 40 on the seat plate 34 and cover the upper end 38a of the refrigerant tube 38 with its fitting hole 40a, and even with a tube protruding type that is easy to manufacture, the bottom wall surface of the upper tank 31 can be easily processed. can be flattened. Further, since the fitting hole 40a of the guide plate 40 is formed in a bell mouth shape above the end surface of the refrigerant tube 38, the flow of steam can be further rectified.

Next, in the embodiment shown in FIGS. 5 and 6, the upper surface of the guide plate 40 is sloped so that the effective space inside the upper tank 31 becomes smaller as the distance from the steam port 36 increases. It is possible to ensure uniform distribution of the refrigerant to each refrigerant tube 38.

<Effects of the Invention> As explained above, according to the condenser for a boiling-cooled engine according to the present invention, steam flows smoothly from the upper tank to the refrigerant tube in the core portion, and pressure loss can be reduced. This brings about the effect that cooling efficiency and the like can be improved.

[Brief explanation of drawings]

FIG. 1 is a front and side sectional view of main parts of a capacitor showing an embodiment of the present invention, FIG. 2 is an overall view of the same capacitor, FIG. 3 is a perspective view of a guide plate used in the same capacitor, and FIG. Figure 4 is a sectional view showing a modified form of part A in Figure 1;
The figure is a sectional view of the main parts of a condenser showing another embodiment, FIG. 6 is an overall view of the same condenser, and FIG. 7 is a configuration diagram showing an example of the cooling system of a boiling-cooled engine in which the condenser according to the present invention is used. , FIG. 8 is a perspective view showing an example of a conventional capacitor, and FIG. 9 is a sectional view thereof. 3... Capacitor 31... Upper tank 32.
... Lower tank 33 ... Core part 36 ... Steam population 37 ... Liquefied refrigerant outlet 38 ... Refrigerant tube 38a ... Upper end 39 ... Cooling fin
40... Guide plate 40a... Fitting hole patent applicant Nissan Motor Co., Ltd. agent Patent attorney Fujio Sasashima, Figure 2, Figure 3, Figure 4

Claims (4)

[Claims] (1) The upper tank is configured to include an upper upper tank having a vapor inlet, a lower lower tank having a liquefied refrigerant outlet, and a core portion consisting of a plurality of vertical refrigerant tubes that communicate the two tanks, and the bottom of the upper tank. A condenser for an evaporative cooling engine, characterized in that an upper end of the refrigerant tube connected to the wall does not protrude into the space within the upper tank. (2) A guide plate having a fitting hole that fits with the upper end of the refrigerant tube protruding from the bottom wall surface of the upper tank is disposed, and this guide plate allows the upper end of the refrigerant tube to be placed in the space within the upper tank. A condenser for an evaporatively cooled engine according to claim 1, which is in a non-protruding state. (3) The condenser for an evaporative cooling engine according to claim 2, wherein the fitting hole of the guide plate is formed in a bell mouth shape above the end surface of the refrigerant tube. (4) A condenser for an evaporative cooling engine according to claim 2 or 3, wherein the upper surface of the guide plate is sloped so as to reduce the space within the upper tank as it moves away from the steam inlet. .