JPS6144497Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a heating device for an automobile with improved heating performance.

Generally, automobile heating systems use cooling water (hot water) that takes heat from the engine as a heat source, but in cold regions, this alone does not have enough heating capacity, so it is possible to recover exhaust heat when the cooling water temperature is low. There are some that have increased heating capacity.

In addition, in order to ensure high heating capacity for a long time even when the heating is used after the engine has stopped, a heat storage device is installed to store exhaust heat while the engine is running, and this heat storage device is used as a heat exchanger to warm the cooling water for heating. Some have done this.

As a conventional automobile heating system equipped with such a heat storage device, the one shown in FIGS. 1 and 2, for example, has been proposed by the present applicant (Utility Application No.
−161361). This system is installed to connect the exhaust system of the internal combustion engine and the cooling system, and is configured to extract heat from the engine's exhaust gas and supply it to the on-vehicle heater using cooling water as a heat medium.

In FIG. 1, reference numeral 1 denotes an engine body, and a heat storage device 3 is interposed in the middle of an exhaust pipe 2 of the engine body. On the other hand, a heater core 5 of a heater unit 4 installed in the vehicle interior is cyclically connected to a cooling water passage 6 of the engine body 1, forming a heat circulation path when heating is used during engine operation. And, in the middle of the circulation route, via the circulation pump 7 and the switching valve 8,
The heat storage device 3 is connected by bypass, and by switching the switching valve 8, a heat circulation path is formed when heating the cooling water when the temperature is low or after the engine is stopped.

FIGS. 2a and 2b are diagrams showing the internal structure of the heat storage device indicated by 3 in FIG. 1. The inside of the heat storage device 3 is filled with a heat storage material 3b, and a plurality of exhaust tubes 3 forming an exhaust passage pass through the heat storage material 3b.
a are arranged in parallel. A cooling water passage 3d is provided between the heat storage material 3b including these exhaust tubes 3a and the heat insulating material 3c forming the outer shell of the heat storage device 3.

Returning to FIG. 1, reference numeral 9 denotes an exhaust bypass passage, which is used to bypass the heat storage device 3 and discharge the exhaust gas in order to protect the heat storage material 3b when the heat storage device 3 is overheated. At this time, the exhaust passage is switched between the heat storage device 3 and the exhaust bypass passage 9.
This is done using the exhaust bypass valve 10 provided at the branch point between the two.

In the above system, while the engine is operating, cooling water circulates between the engine body 1 and the heater core 5 to heat the passenger compartment, and during this time a part of the exhaust heat is stored in the heat storage device 3. It is becoming more and more popular.

When the cooling water is low or after the engine has stopped, selector valve 8
By switching and connecting the cooling water passage between the heat storage device 3 and the heater core 5, the heat stored in the heat storage device 3 is supplied to the heater core 5 through the cooling water. .

Therefore, heating performance in cold weather can be improved, hot water can be supplied for a relatively long period of time even after the engine has stopped, and heating performance can be maintained satisfactorily when the vehicle is stationary.

However, in the case of such conventional devices, even when heating is not performed and there is no need to extract heat from the heat storage to the cooling water after the engine is stopped, the heat storage material and the adjacent cooling water passage are However, since the cooling water remained in the system, there was a problem in that the heat stored in the heat storage material was radiated to the cooling water completely meaninglessly.

Furthermore, as mentioned above, the heat dissipation from the heat storage material to the cooling water does not simply result in the stored heat not being utilized and becoming a loss, but also because it absorbs this heat and generates high temperatures. High-pressure cooling water may deform or damage the cooling water passages, or antifreeze may be mixed into the cooling water (because heat storage units are used in cold regions, this is often the case). When the cooling water is exposed to high temperatures due to heat dissipated from the heat storage material, the components of the antifreeze may oxidize, decompose, or corrode, leading to deterioration of the cooling water. Furthermore, there are also problems such as the decomposition products and the like causing valve opening/closing failure and route closure.

In addition, in order to prevent the adverse effects caused by thermal decomposition of the antifreeze, a heat exchanger and a heat storage device outside the exhaust passage are connected in a closed loop, and a circulation path is filled with a condensable working fluid such as pure water that does not contain antifreeze. There has also been proposed a system in which heating is performed indirectly by passing heating cooling water through a heat exchanger in this circulation path. However, in conventional systems of this kind, the working fluid freezes at low temperatures, damaging the heat storage device and circulation path, and it takes too long for the fluid to thaw and start circulating, making it impossible to provide quick heating. There was a problem.

The present invention was devised in view of these conventional problems, and it is possible to recover engine exhaust heat from the condensing side heat exchanger of the condensable working fluid circulation path that indirectly heats the cooling water for heating. An intermediate tank is installed outside the exhaust passage to warm the condensate when heating is in use and the working fluid is not circulating, in the middle of the passage leading to the heat storage device in the lower exhaust passage; and an intermediate tank is installed outside the exhaust passage to store condensate when heating is not in use. To provide a heating device for an automobile which solves the above-mentioned problems by having a configuration in which a reservoir tank provided in an exhaust passage is connected in series, and an on-off valve is provided between an intermediate tank and a reservoir tank. With the goal.

The present invention will be explained below based on the embodiment shown in FIG.

However, in FIG. 3, the same components as in FIG. 1 are given the same reference numerals and explained. In the figure,
In the middle of the exhaust pipe 2 of the engine body 1, a reservoir tank 11 and a heat accumulator 12 are arranged side by side in the exhaust flow direction, and fins 11 are provided on the outer walls of each of these.
a, 12a are provided to improve heat transfer performance.
These reservoir tank 11 and heat accumulator 12 are connected by a pipe 15.

Further, the outlet of the evaporator pipe 13 in the heat storage device 12 and the inlet of the condensing pipe 17 in the condenser 16 disposed above the exhaust pipe 2 are connected by a pipe 18.
The outlet of 6 and the reservoir tank 11 are the intermediate tank 1
9 and a pipe 2 with an on-off valve 20 interposed below it
Connected by 1. A condensable working fluid such as pure water that does not contain antifreeze is sealed in the circulation path connected in a closed loop in this manner. The reservoir tank 11 and the intermediate tank 19 are each formed to have a capacity that can store the entire amount of the working fluid condensate in the circulation path.

On the other hand, a water jacket 22 formed outside the condensing pipe 17 of the condenser 16 is connected in series with the outgoing path from the engine body 1 to the heater core 5 in the middle of the heating cooling water passage 23 that passes through the heater core 5 in the heater unit 4. It is connected to the.

Further, water temperature sensors 24 and 25 are provided in the reservoir tank 11 and the heating cooling water passage 23, respectively.
For example, the amount of water in the tank 11 is the set value (for example, 80
℃) and when heating is performed when the engine cooling water temperature is higher than the set value, the on-off valve 20 is opened and the pump 14 is driven. After this period, the valve is opened unconditionally.

Next, the effect will be explained. In cold weather or after the engine has stopped,
When the cooling water temperature falls below the set value and the water temperature in the reservoir tank 11 exceeds the set value, the on-off valve 20 is opened as described above, and the pump 14 is driven to circulate the working fluid. In this case, the vapor of the working fluid heated and vaporized by the heat storage device 12 is passed through the pipe 18 to the condenser 16.
The water flows into the condensing pipe 17, where it radiates heat to the heating cooling water flowing in the adjacent water jacket and is condensed. Returned to 13. In this way, in the condenser 16, the cooling water heated by exchanging heat with the working fluid circulates through the heater core 5, thereby increasing heating efficiency. Furthermore, if the engine is stopped,
Cooling water is forcibly fed to the heater core 5 by an electric pump (not shown) interposed in the heating cooling water passage.

In addition, when the cooling water temperature reaches a predetermined temperature or higher and heating is performed while the engine is operating at a sufficiently high temperature, there is no need to recover exhaust heat, and the on-off valve 20 closes and the pump 14 is stopped, so the operation is stopped. The fluid circulation is stopped and the heat supply from the working fluid to the heating cooling water is cut off, preventing overload operation of the heating.
The condensed liquid of the working fluid cooled by the condenser 16 is stored in the intermediate tank 19 on the upstream side of the on-off valve 20. When the working fluid is not circulated in this way, the condensing pipe is stored in the intermediate tank 19,
Since it is prevented from accumulating in the heat storage device 12, it is possible to prevent unnecessary temperature drop due to heat radiation to the condensate in the heat storage device 12, and it is possible to further improve the heating performance after the engine is stopped and immediately after heating is resumed, and at the same time, the cooling water It is also possible to prevent thermal deformation and damage to the heat storage device 12 due to high temperature and high pressure. Furthermore, since the cooling water is heated via the working fluid, adverse effects such as thermal decomposition of antifreeze in the cooling water in the high-temperature heat storage device 12 can be avoided.

Next, when the engine is stopped and the heating is also stopped, the on-off valve 20 is opened a predetermined time after the engine is stopped, and the condensed liquid flows down into the reservoir tank 11 and accumulates therein. If condensate is stored in the reservoir tank 11 for a long time in cold weather, the condensate flow in the reservoir tank 11 will freeze, but since the reservoir tank 11 is interposed in the exhaust pipe 2, the engine It is quickly thawed by exhaust heat during restart, and heating can be performed by immediately driving the pump 14 to circulate the working fluid. In addition, since the working fluid is stored and frozen in the reservoir tank 11, which has a relatively simple structure, the working fluid pipes and the heat accumulator 1 are
Damage caused by freezing as described in No. 2 can also be effectively prevented.

As explained above, according to the present invention, by providing an intermediate tank to store the condensed liquid when the working fluid is not circulating, the temperature drop due to heat radiation from the condensing pipe of the heat storage device is suppressed, and the temperature can be recovered after the engine is stopped or when the exhaust heat is removed. It is possible to further improve the heating performance when recovery is resumed, and also to prevent thermal deformation and damage to the heat storage device.In addition, since the engine cooling water for heating is heated in the condenser via the working fluid, it is possible to The antifreeze liquid is not exposed to high temperatures in the heat storage device, and thermal decomposition can also be prevented. Furthermore, after the heating stops, the condensate of the working fluid is stored in a reservoir tank installed in the exhaust passage, so even if it freezes in extremely cold weather, it will quickly thaw with the exhaust heat when the engine is started, providing heating by recovering exhaust heat. The start-up performance of the system is also improved, and damage to working fluid pipes and heat storage devices due to freezing can be effectively prevented.

[Brief explanation of drawings]

Fig. 1 is a schematic configuration diagram showing the overall system configuration of a conventional automobile heating device, and Fig. 2a is a vertical sectional view showing an example of the internal structure of a heat storage device used in the device shown in Fig. 1. b is a sectional view taken along the line a in FIG. 3, and FIG. 3 is a block diagram showing the main part of an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1...Engine body, 2...Exhaust pipe, 5...Heater core, 11...Reservoir tank, 12...Regenerator, 16...Condenser, 19...Intermediate tank, 20...Opening/closing valve, 23... ...Cooling water passage for heating.

Claims (1)

[Scope of utility model registration request] A condensable working fluid circulation path formed by cyclically connecting a heat storage device installed in an exhaust passage of an on-vehicle internal combustion engine and a condenser provided above the outside of the exhaust passage, the condensing side heat exchanger, and a heating heater core. In the automotive heating system, the heating system has an engine cooling water circulation path for heating, which is connected to the heating engine cooling water circulation path, and an intermediate tank is provided outside the exhaust path in the path for returning working fluid from the condenser to the heat storage device, and a reservoir is provided in the exhaust path. The tanks are interposed and connected in this order, and an on-off valve is interposed between the intermediate tank and the reservoir tank, which opens when heating is in use and when the working fluid is not circulating or when heating is stopped, and closes at other times. An automotive heating device characterized by: