JPH025261B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an engine cooling water supply and recovery device installed in an engine test bench for performing various tests by igniting an assembled engine. be.

(Prior art) In order to ignite an engine set on an engine test bench, cooling water adjusted to a predetermined water temperature must be supplied to the test engine, and high-temperature waste water discharged from the test engine must be collected. However, conventional engine cooling water supply and recovery equipment used in such applications does not allow wastewater to be discharged from the engine test bench via the test engine, or discharged from the engine test bench without passing through the test engine. Cooling water recovery means for returning unused cooling water to the tank was constructed using a vacuum pump. That is, the system was configured to suck waste water or unused cooling water from the engine test bench using negative pressure in a vacuum tank (charge tank) with a cooler that is depressurized by a vacuum pump and return it to the tank.

(Problems to be Solved by the Invention) In the conventional engine cooling water supply and recovery device as described above, the cooling water recovery means requires a vacuum pump and a vacuum tank with a cooler, so the equipment cost is extremely high. It is also very noisy when driving. Moreover, the biggest problem is that the recovered engine cooling water is cooled in a vacuum tank with a cooler, which increases the amount of heat required for heating when recirculating it.
The reason is that operating costs are high.

(Means for Solving the Problems) In order to solve the above conventional problems, the present invention provides a cooling water supply means for supplying engine cooling water to an engine test bench, and a cooling water supply means for supplying engine cooling water to an engine test bench, and a cooling water supply means for supplying engine cooling water to an engine test bench. Cooling water recovery means for returning wastewater discharged from the test bench or unused cooling water discharged from the engine test bench without passing through the test engine to the return tank, the cooling water recovery means includes a recovery pipe. The present invention proposes a cooling water supply and recovery device for engine testing, which includes a water ejector interposed therein, and a pump that pumps hot water in the return tank to the water ejector as driving water.

(Operation of the invention) The engine cooling water supplied to the engine test bench by the cooling water supply means is supplied to the engine test bench after passing through the test engine set in the engine test bench, or when the test is stopped, etc., without passing through the test engine. , is sucked into the water ejector and returned to the return tank. At this time, since the hot water in the return tank is used as driving water for the water ejector, the high-temperature waste water or unused cooling water sucked into the water ejector is not cooled, but is returned to the return tank in a high-temperature state. Therefore, when the hot water in the return tank is circulated and used by the cooling water supply means, the amount of heat required for reheating can be reduced.

(Embodiment) An embodiment of the present invention will be described below based on the attached illustrative drawings. In Fig. 1 showing a hot water unit, 1 is a main tank (header tank) installed at a high place. , heaters 2a, 2b, temperature sensors 3a, 3b, and float switch 4a
~4d. Reference numeral 5 denotes a return tank, which is equipped with a heater 6, a temperature sensor 7, and float switches 8a to 8d. Reference numeral 9 denotes a drain pipe from the main tank 1, which is equipped with a main tank drain valve 10, and is arranged so that the drain water is supplied to the return tank 5. 11 is a drainage pipe from the return tank 5, and is equipped with a return tank drainage valve 12. 13 is a water supply pipe from the return tank 5 to the main tank 1, and is equipped with a return pump 14. 15
Numerals a and 15b are water supply pipes that supply water from the water supply connection end 16 to the main tank 1 and the return tank 5, respectively, and are provided with water supply valves 17 and 18, respectively.
Reference numerals 19a to 19e are engine test benches, in which each cooling water supply source connection end 20 and the main tank 1 are connected by a water supply pipe 21, and each test bench 19a to 19e is connected to a drainage suction source connection end 22. The connected recovery pipe 23 opens onto the return tank 5. 24a to 24d are water ejectors, which are interposed in parallel in the recovery pipe 23, and these water ejectors 24
Two ejector pumps 2 that divide a to 24d into two groups and supply driving water to the water ejectors of each group.
5a and 25b are connected to a hot water take-out pipe 26 connected to the return tank 5.

FIG. 2 shows each engine test bench 19a~
Showing the cooling water supply and recovery piping system in 19e,
27 is the engine to be tested; 28 is a water supply pipe between the cooling water supply source connection end 20 and the cooling water inlet of the engine 27; and 29 is between the cooling water outlet of the engine 27 and the drainage suction source connection end 22. 30 is a bypass pipe connecting the water supply pipe 28 and the recovery pipe 29; 31 is the bypass pipe 3;
This is an on-off solenoid valve installed in the valve 0, which shuts off the bypass piping 30 in the OFF state. 32 is located closer to the engine 27 than the connection position of the bypass pipe 30.
A drainage pipe 33 is connected to the recovery pipe 29 on the side, and 33 is a switching solenoid valve installed in the water supply pipe 28, and in the OFF state, the water supply pipe portion on the engine 27 side from the switching solenoid valve 33 is connected to the water supply pipe 33. 28a
is connected to the drainage pipe 32. 34 is an opening/closing solenoid valve interposed in the water supply piping portion 28a on the side of the engine 27 from the switching solenoid valve 33,
In the OFF state, the water supply piping portion 28a is shut off. Reference numeral 35 denotes a differential pressure flow switch installed in the drain pipe 32, which opens and closes the solenoid valve in the water supply pipe 28 when the water flow in the drain pipe 32 is no longer detected. 34
Automatically switches from an ON state (a state in which the water supply pipe 2 is communicated) to an OFF state in which the water supply pipe 28 is cut off. 36 is a switching solenoid valve installed in the recovery pipe 29 on the engine 27 side from the connection position of the drain pipe 32, and in the OFF state, the recovery pipe portion on the engine 27 side from the switching solenoid valve 36. 29a is connected to the atmosphere opening pipe 37. Reference numeral 38 denotes a check valve interposed in the air release pipe 37.

Next, to explain how to operate the hot water unit shown in FIG. 1, the hot water unit is operated in two modes: an initial mode, which mainly adjusts the water volume in the main tank 1 and the return tank 5; Idling mode for adjustment,
Test bench 19 after adjusting water volume and temperature
An operating mode that maintains a state in which water can be supplied to a to 19e is set in advance.

(Initial Mode Operation) Operation control based on the initial mode selected at the start of operation is performed as follows.

(1) For heaters 2a and 2b, float switch 4d, which detects the lower limit water volume of main tank 1, is turned on.
It operates on the condition that heater 6
operates on the condition that the float switch 8d, which detects the lower limit water amount in the return tank 5, is ON.

(2) When the water levels in both tanks 1 and 5 are below the standard water level, that is, the standard water level detection float switch 4
When both b and 8c are OFF, the main tank water supply valve 17 and return tank water supply valve 18 are closed until the respective float switches 4b and 8c are turned ON.
opens, and water supply pipes 15a, 1 are connected to both tanks 1, 5.
Water is supplied through 5b.

(3) When the water level in the main tank 1 is above the standard water level and the water level in the return tank 5 is below the standard level, the main tank drain valve 1 is closed until the float switch 4b for detecting the standard water level in the main tank 1 is turned OFF.
0 is opened and the main tank 1 is drained through the drain pipe 9.
When the water in the return tank 5 is supplied to the return tank 5 and the drain valve 10 is closed, if the water level in the return tank 5 is still below the standard water level, the water supply valve 18 is closed until the standard water level detection float switch 8c is turned on.
is opened, and the return tank 5 is opened from the water supply pipe 15b.
When water is supplied from the main tank 1 and the amount of water in the return tank 5 exceeds the standard water amount, the float switch 8c is activated.
The return tank drain valve 12 opens until it is turned OFF, and the water in the return tank 5 is discharged through the drain pipe 11.

(4) When the water volume in the return tank 5 is above the standard water volume and the water volume in the main tank 1 is below the standard water volume,
The water supply valve 17 is opened until the float switch 4b is turned on, and water is supplied to the main tank 1 from the water supply pipe 15a, and the return tank drain valve 1 is opened until the float switch 8c is turned off.
2 opens, and the return tank 5 is discharged from the drainage pipe 11.
The water inside will be drained.

(5) If the water levels in both tanks 1 and 5 are both above the standard water level, the respective float switches 4b and 8c are activated.
The main tank drain valve 10 and the return tank drain valve 12 are opened until it is turned OFF, and each tank 1,
Water in 5 is discharged through drain pipes 9 and 11.

(Idle mode operation) As a result of the water amount adjustment in the initial mode operation, the water supply valves 17 and 18 and the drain valves 10 and 12
When all of the circuits remain closed for a certain period of time (eg, 5 seconds), the initial mode operation is automatically switched to idling operation.

(1) The heaters 2a and 2b of the main tank 1 operate until the main tank water temperature reaches the maximum set temperature (e.g. 68°C, detected by the temperature sensor 3a).
The heater 6 of the return tank 5 operates until the return tank water temperature reaches the minimum set temperature (eg, 50° C., detected by the temperature sensor 7).

(2) Specified water volume for main tank 1 (below the standard water volume)
When the detection float switch 4c is ON and the water temperature in the main tank 1 is above the maximum setting temperature and the water temperature in the return tank 5 is below the minimum setting temperature, the main tank drain valve 1 is activated.
0 is opened, and hot water in the main tank 1 is supplied to the return tank 5 through the drainage pipe 9.

(3) When the float switch 4b for detecting the standard water level of the main tank 1 is OFF and the float switch 8c for detecting the standard water level of the return tank 5 is ON, the flow rate will continue until the float switch 4b is turned ON or the specified water level of the return tank 5 ( Standard water amount or higher) Detection float switch 8b is ON.
When the float switch 4a for detecting the upper limit water level of the main tank 1 is OFF, the return tank 5
The float switch 8c for detecting the standard water amount is
The return pump 14 operates until it is turned off.
Hot water in the return tank 5 is supplied to the main tank 1 through the water supply pipe 13.

(Operating mode operation) When the state in which the hot water in the main tank 1 is higher than the maximum set temperature and the hot water in the return tank 5 is higher than the lowest set temperature continues for a certain period of time (e.g., 5 seconds) due to the idling mode operation. , automatically switches from idling mode to running mode.

(1) The main tank water supply valve 17 opens when the main tank water temperature is higher than the maximum set temperature and the float switch 4c for detecting the specified water amount of the main tank 1 is OFF, and water is supplied to the main tank 1.

(2) The main tank drain valve 10 is connected to the float switch 8c for detecting the reference water level of the return tank 5.
When the float switch 4c for detecting the specified water level in the main tank 1 is OFF and the float switch 4c for detecting the specified water level in the return tank 5 is ON, the float switch 8b for detecting the specified water level in the return tank 5 is turned on.
It opens until it turns on, and the hot water in the main tank 1 is supplied to the return tank 5. Alternatively, when the main tank water temperature is higher than the maximum set temperature, the float switch 4b for detecting the reference water level of the main tank 1 is activated.
When ON, the main tank drain valve 10 can also be opened.

(3) When the return tank water temperature is higher than the maximum set water temperature (e.g. 60°C, detected by the temperature sensor 7), the return tank water supply valve 18 is activated by the float switch 8b for detecting the specified water volume of the return tank 5 or the float switch 8c for detecting the reference water volume. is OFF, the float switch 8b for detecting the specified water amount is ON.
The return tank 5 is opened until water is supplied to the return tank 5.

(4) The return tank drain valve 12 is operated by the float switch 8a for detecting the upper limit water amount of the return tank 5.
When ON, the float switch 8b for detecting the specified water level opens until it turns OFF, and the return tank 5
Drainage is carried out from.

(5) The heater 2a of the main tank 1 operates when the main tank water temperature is below the minimum set temperature (for example, 62°C, detected by the temperature sensor 3a) until the water temperature reaches the maximum set temperature.

(6) The heater 2b of the main tank 1 is configured such that the main tank water temperature remains at the intermediate set temperature (for example, 65 minutes) even after a certain period of time (for example, 5 minutes) has passed after the heater 2a is activated.
℃, detected by temperature sensor 3b), the water temperature operates until the water temperature reaches the maximum set temperature.

(7) The heater 6 of the return tank 5 operates when the return tank water temperature is below the minimum set temperature until the water temperature reaches the maximum set temperature.

(8) When the float switch 4c for detecting the specified water amount of the main tank 1 is turned OFF, the return pump 14 operates so that the water temperature of the main tank 1 is equal to or higher than the minimum set temperature and the float switch 4c for detecting the lower limit water amount of the return tank 5 is turned off. It operates on the condition that 8d is ON, and stops when the float switch 4a for detecting the upper limit water amount of the main tank 1 is turned ON. Incidentally, when the float switch 4b for detecting the standard water level of the main tank 1 is turned on due to the operation of the return pump 14,
If the main tank water temperature is below the intermediate set temperature, the return pump 14 is stopped by turning on the float switch 4b.

(9) The water ejectors 24a to 24d are constantly operated by ejector pumps 25a and 25b,
Hot water supplied from the main tank 1 to the test benches 19a to 19e via the water supply pipe 21 is sucked by the water ejectors 24a to 24d, and is collected into the return tank 5 via the recovery pipe 23.

While the hot water unit is being operated in the above operation mode, each test bench 19a~
A test operation of the engine 27 is performed at 19e. Of course, even in this operating mode, if the main tank water temperature remains below the minimum set temperature for a certain period of time (e.g. 5 minutes),
Engine test operation on test benches 19a to 19d is disabled.

When the engine 27 is at rest and is not being tested, the switching solenoid valves 33 and 36 and the opening/closing solenoid valve 3
4 in the OFF state as shown in the figure, and only the on-off solenoid valve 31 in the bypass piping 30 is in the ON (open) state to adjust the temperature in the main tank 1 that is supplied from the cooling water supply source connection end 20 at head pressure. The cooled water is circulated through the bypass pipe 30 and returned to the drain suction source connection end 22. When test driving the engine 27, first switch the switching solenoid valve 36 in the recovery pipe 29 to the ON state to connect the recovery pipe 29, and return the open/close solenoid valve 31 in the bypass pipe 30 to the OFF state to close the bypass pipe 30. After that, the switching solenoid valve 33 and the opening/closing solenoid valve 34 in the water supply piping 28 are turned on with a slight delay, and the water supply piping 28 is shut off.
communicate. As a result, the cooling water supply source connection end 2
The cooling water supplied from the engine 27 to the water supply pipe 28 is supplied to the engine 27, and the cooling water discharged from the engine 27 is passed from the recovery pipe 29 to the wastewater suction source connection end 2.
2 through the water ejectors 24a to 24
d and collected in the return tank 5.

After the engine test is completed, only the open/close solenoid valve 34 in the water supply pipe 28 is left in the ON state, and the other switching solenoid valves 33 and 36 are switched to the OFF state. As a result, the recovery piping section 29a connected to the engine 27 is connected to the atmospheric release piping 37, and at the same time, the water supply piping section 29a connected to the engine 27 is connected to the atmosphere release piping 37.
8a communicates with the drainage suction source connection end 22 through a part of the drainage pipe 32 and the recovery pipe 29. Therefore, the water ejectors 24a-2
A suction force of 4d is applied to the water supply pipe portion 28a and the engine 2.
7 and the recovery piping portion 29a, the cooling water remaining in these cooling water supply and recovery paths is forcibly drawn in the opposite direction to that when the cooling water is supplied, and is automatically discharged. At this time, the atmosphere is introduced into the cooling water supply and recovery path from the atmosphere release pipe 37;
When suction and discharge of the residual cooling water is completed and there is no water flow in the drain pipe 32, the differential pressure type flow switch 35 in the drain pipe 32 is activated, and the on-off solenoid valve 34 is automatically switched to the OFF state. Since the water supply piping portion 28a is shut off, air is not drawn into the drainage suction source.

In addition, as in the embodiment, by using a water flow detection switch (differential pressure type flow switch 35 in the embodiment) to prevent air from being sucked during the suction and recovery of residual cooling water after the engine test is completed,
Although a water ejector with low suction capacity is used, an effective suction and recovery action can be performed. Further, even when a plurality of water ejectors are installed in parallel to obtain the necessary suction capacity as in the embodiment, the number of water ejectors used can be reduced.

As part of the heat source for adjusting the temperature of the engine cooling water, high-temperature cooling water recovered from the oil cooler of the hydraulic unit attached to the engine test equipment and high-temperature exhaust gas from the engine being tested are used. By doing so, a heater with a small capacity can be used, resulting in cost reduction and energy saving effects.

Further, in the above embodiment, the cooling water supply means for supplying engine cooling water to the engine test bench is connected to the heaters 2a, 2b and the water supply means (water supply pipe 15a).
It consists of a main tank 1 installed at a high place with a main tank water supply valve 17), and a water supply pipe 21, and is used to discharge wastewater from an engine test bench via a test engine, or to perform an engine test without passing through a test engine. The cooling water recovery means for returning the unused cooling water discharged from the bench to the return tank includes a recovery pipe 23, water ejectors 24a to 24d installed in the recovery pipe 23, and a cooling water recovery unit that returns the unused cooling water discharged from the bench to the return tank. Ejector pump 2 that pumps driving water to the water ejector
5a and 25b, the specific structure is not limited to that of the above embodiment.

(Effects of the Invention) As described above, according to the engine test cooling water supply and recovery device of the present invention, since the cooling water is recovered not by a vacuum pump but by a water ejector, equipment costs can be significantly reduced. This also solves the problem of noise during operation. Moreover,
There is no risk of unduly cooling high-temperature wastewater or unused cooling water when it is sucked in by the water ejector, so the expense required for reheating when recycling the recovered wastewater collected in the return tank is reduced, making it more economical. It is true.

[Brief explanation of drawings]

Fig. 1 is a piping system diagram of the hot water unit, and Fig. 2 is a piping system diagram on the test bench side. 1...Main tank, 2a, 2b, 6...Heater, 3a, 3b, 7...Temperature sensor, 4a~
4d, 8a-8d...Flow switch, 5...Return tank, 10...Main tank drain valve, 1
2...Return tank drain valve, 14...Return pump, 17...Main tank water supply valve, 18...
Return tank water supply valve, 19a-19e...Engine test bench, 20...Cooling water supply source connection end, 22...Drainage suction source connection end, 24a-24d
... Water ejector, 25a, 25b ... Ejector pump, 27 ... Engine, 28 ... Water supply pipe, 29 ... Recovery pipe, 30 ... Bypass pipe, 32 ... Drainage pipe, 35 ... Differential pressure type flow switch, 37... Piping for opening to the atmosphere.

Claims (1)

[Claims] 1 A cooling water supply means for supplying engine cooling water to an engine test bench, and waste water discharged from the engine test bench via the test engine, or unused water discharged from the engine test bench without passing through the test engine. A cooling water recovery means for returning the cooling water to the return tank, the cooling water recovery means includes a water ejector interposed in the recovery piping, and a water ejector for pressurizing hot water in the return tank to the water ejector as driving water. A cooling water supply and recovery device for engine testing, which is equipped with a pump for cooling.