JPS6223613Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a hot water heating system for a vehicle, and more particularly to a hot water heating system for a vehicle that can safely operate a hot water heater.

Conventionally, vehicle hot water heating systems used in buses and the like use a water pump 2 to pressurize hot water whose temperature has risen by cooling a main engine 1 for driving the vehicle, as shown in Fig. 1. A circulating circuit is configured in which water is sent to a hot water heater 3, further heated, heat exchanged with a heating heat exchanger 4, and the water whose temperature has decreased is sent to the main engine 1 to cool the engine.

However, since heating is generally required only in the winter, it is necessary to prevent the hot water heating circuit from operating when heating is not required, such as in the summer and intermediate seasons. Therefore, another circulation circuit is provided to circulate cooling water between the main engine 1 and the radiator 5. That is, first, shutoff valves 6 and 7 are provided in the hot water heating circuit to prevent hot water from flowing into this circuit. The main outflow pipe 8 through which hot water flows out from the main engine 1 includes a pipe 8a leading to the radiator 5 and an outflow pipe 9a from the radiator 5. A cooling water circulation circuit is connected to the pipe line 9 and circulates only between the main engine 1 and the radiator 5 during summer or the like. The shutoff valve 7 is a manual valve that is closed during the summer and opened during the winter. To operate the heating circuit, turn on the heating switch on the control panel (not shown), and current is applied to the blower 10 that sends air inside the vehicle to the electromagnetic shutoff valve 6, water pump 2, hot water heater 3, and heat exchanger 4. flows,
The shutoff valve 6 is opened, and the pump 2, hot water heater 3, and blower 10 start operating.

In such a conventional heating device, the manual valve 7 is opened during heating, and the solenoid valve 6 must be opened reliably.

However, if the heating switch is turned on without opening the manual valve 7, or if the solenoid valve 6 is broken and the shutoff valve remains closed, hot water will not circulate even if the water pump 2 is activated. . Therefore, since the hot water inside the hot water heater 3 is stationary, the temperature rises rapidly, causing accidents such as destruction of the boiler, injuring passengers, and cooling water flowing out from the destruction. This can cause problems such as overheating the main engine. Furthermore, if heating becomes impossible during cold weather due to heater damage, the temperature inside the vehicle will drop extremely, which may affect human life depending on regional conditions.

[Purpose of the invention]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a hot water heating system for a vehicle that eliminates the drawbacks of the conventional systems described above and can be operated safely without causing overheating accidents.

[Structure of the idea]

In order to achieve the above object, the vehicle hot water heating system according to the present invention is a circulation type vehicle hot water heating system in which water used to cool the engine is sent to a hot water heater, where it is heated and used for heating. A hot water circulation detection device is provided in the pipe between the engine and the hot water heater,
The hot water heater is operated only when hot water is circulating.

[Example of idea]

Hereinafter, an embodiment of the hot water heating system for a vehicle according to the present invention will be described with reference to FIG. 2, in which the same parts as in FIG. 1 are denoted by the same reference numerals.

As shown in FIG. 1, the hot water circulation circuit used for heating large vehicles such as buses cools the main engine 1 and circulates the coolant whose temperature has risen with the shutoff valves 6 and 7 open. The water is pressurized by the water pump 2, sent to the hot water heater 3, further heated to raise the water temperature, sent to the heat exchanger 4, where it exchanges heat with the cold air in the passenger compartment, and the hot water whose temperature has dropped is returned to the main engine 1. The structure is such that the cycle is repeated. Furthermore, during periods when heating is not required, the electromagnetic shutoff valve 6 and the manual shutoff valve 7 are closed, and a circuit is provided in which cooling water circulates between the main engine 1 and the radiator 5. Note that this cooling water circulation circuit is provided with a bypass pipe and a valve 11 so that the flow rate to the radiator 5 can be adjusted.

In the hot water circulation circuit configured in this way,
A hot water temperature sensor 12 is installed in a pipe near the engine outlet side of hot water flowing out from the main engine 1, and
A hot water temperature sensor 13 is provided in a conduit downstream of the electromagnetic shutoff valve 6 and close to the hot water inlet side of the hot water heater 3 . Then, the water temperature information detected by both sensors 12 and 13 is transmitted to the line 12a.
The data can be input to the controller 14 via 13a and 13a. The controller 14 compares the water temperatures detected by the temperature sensors 12 and 13, and if the temperature difference is smaller than the preset value Δt, the controller 14 determines that hot water is flowing in the heating hot water circuit, and turns the hot water heater on. Activate 3. If shutoff valve 6 or 7
If it remains closed, hot water will not circulate, and the temperature difference between sensors 12 and 13 will be the set value △
t, the controller 14 immediately stops the operation of the hot water heater 3 via the output line 14a.

Further, when starting the main engine, it takes time for the temperature of the cooling water to rise, so there may be no temperature difference between the sensors 12 and 13 even if water is not flowing in the hot water circuit. Therefore, the controller 14 is provided with a delay means, such as a timer, so that the hot water heater 3 does not operate for T minutes immediately after the main engine 1 starts even if the temperature difference between the sensors 12 and 13 is less than the desired value Δt. A delay time of T minutes is provided.

FIG. 3 shows another embodiment of the present invention,
The hot water flow rate in the hot water piping is detected by the pitot tube 15, and the hot water heater 3 is enabled to operate only when the flow rate is larger than a predetermined value V by the controller 16.
When the flow rate is less than V, it is determined that the hot water circulation is not normal, and the operation of the hot water heater 3 is stopped.

Reference numeral 17 is an engine oil pressure sensor, which is used to detect the start of the engine by an increase in oil pressure and turn on the control system.

As is clear from the above explanation, according to the present invention, temperature sensors are provided on the upstream and downstream sides of the shutoff valve of the hot water heating circuit, and the hot water heater is activated and stopped based on the temperature difference. Since the operation of the hot water heater can be controlled by detecting the flow velocity of operation can be stopped. Therefore, damage caused by overheating of the hot water heater and dangers caused by overheating of hot water, which conventionally occur, can be prevented. Furthermore, secondary disasters such as overheating of the main engine caused by damage can be prevented. Furthermore, as the factors that cause overheating are reduced, the number of replacements of fuses that blow during overheating is reduced, and maintenance costs can be reduced.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram showing a hot water circulation circuit of a conventional vehicle hot water heating system, Fig. 2 is an explanatory diagram of a hot water circulation circuit showing an embodiment of a vehicle hot water heating system according to the present invention, and Fig. 3 is a similar diagram. FIG. 7 is an explanatory diagram of a hot water circulation circuit according to another embodiment. 1...Main engine, 2...Water pump, 3
...Hot water heater, 4...Heat exchanger, 6,7...Closing valve, 12,13...Temperature sensor, 14,1
6... Controller, 15... Pitot tube.

Claims (1)

[Scope of Claim for Utility Model Registration] 1. In a circulation-type vehicle hot water heating system that sends water that has cooled the engine to a hot water heater and further heats it for use in heating, a pipe line between the engine and the hot water heater A hot water heating device for a vehicle, characterized in that a hot water circulation detection device is provided and a hot water heater is operated only while hot water is being circulated. 2 If the temperature difference between the water temperature detected by the sensor that detects the water temperature in the engine outlet side pipe, the sensor that detects the water temperature in the hot water heater inlet side pipe, and the above two sensors is greater than or equal to the set value, the hot water The hot water heating system for a vehicle according to claim 1, characterized in that it is equipped with a device for stopping the operation of the heater. 3. A request for registration of a utility model characterized in that it is equipped with a sensor that detects the flow rate of hot water in a pipe on the inlet side of a hot water heater, and a device that stops the operation of the hot water heater when the flow rate is less than a set value. The hot water heating system for a vehicle according to scope 1. 4. The hot water heating system for a vehicle according to claim 1, which is characterized by being equipped with a delay device that starts the hot water heater after a certain period of time has elapsed after starting the engine.