JPH0427747A - Liquid-storage-tank-fitted exhaust heat utilizing device for plural engines - Google Patents

Abstract

PURPOSE:To reduce the ratio of the surface area of a liquid storage tank to the volume thereof for reducing the radiating heat loss from the tank by providing one liquid storage tank to a plurality of exhaust-heat taking-out parts of a plurality of engines. CONSTITUTION:One liquid storage tank 24 is provided to a plurality of exhaust- heat taking-out parts 15 to 17 of a plurality of engines 11 to 13. The storage capacity of this one liquid storage tank 24 is set to the capacity equivalent to the aggregate of respective heat quantities of engine exhaust heat taken out from a plurality of exhaust-heat taking-out parts 15 to 17 of a plurality of engines 11 to 13, and the total of respective heat quantities of engine exhaust heat taken out from a plurality of exhaust-heat taking-out parts 15 to 17 of a plurality of engines 11 to 13 is supplied to the one liquid storage tank 24.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention is directed to a vehicle equipped with a plurality of engine working machines equipped with exhaust heat recovery devices, such as a fuel generation device and a heat bomb device. This invention relates to a waste heat utilization device with a liquid storage tank, which collects the waste heat into liquid in a liquid storage tank and uses it for hot water supply, space heating, etc.

(Prior art) Conventionally, this type of waste heat utilization device with a liquid storage tank is
There is the following configuration that was previously conceived by the inventor.

For example, as shown in FIG. 9, one cogeneration device 11 is provided with a hot water tank 94, and the other cogeneration device t2 is also provided with a hot water storage tank 94, and each engine of each cogeneration device 1 and 2 is provided with a hot water storage tank 94. 11.1
The engine exhaust heat extracted from each of the exhaust heat extraction sections 15 and 16 of 2 is transferred to each hot water storage tank 94 via each exhaust heat recovery circuit 19 and 20.
(Problem to be Solved by the Invention) According to this conventional structure, even if one of the engines 11 cannot be operated due to maintenance or failure, However, by operating the other engine 12, the power supply and air conditioning operation can be prevented from being interrupted.

However, the following problem remained.

The hot water tanks 94 and 94 are connected to the cogeneration device i1.
Since they are provided for every two engines, the surface area of the tank must be large relative to the total hot water storage capacity that corresponds to the total amount of exhaust heat from both engines 11 and 12. Therefore, there is a lot of heat radiation loss, and the recovery rate of engine exhaust heat is correspondingly low.

In addition, the tap water population of two hot water tanks 94 and 94 is 94a and 9.
4a to each other to the water pipes, and the hot water outlet 94b.
・Since the 94b must be connected to the hot water supply piping, it takes time and effort to connect the piping.

An object of the present invention is to reduce heat radiation loss in a liquid storage tank that stores hot water or the like, and to facilitate piping connection of the liquid storage tank.

(Means for Solving the Problems) In order to achieve the above object, the present invention is characterized in that an exhaust heat utilization device with a liquid storage tank for a plurality of engines is configured as follows.

(Invention of Claim 1) For example, FIG. 1 or FIG. 3, FIG. 4, FIG. 5, FIG.
As shown in FIG. 7 or FIG. 8, each exhaust heat extraction section 15 of a plurality of engines 11, 12, 13
- The exhaust heat from each engine collected from 16 and 17 is supplied to the liquid storage tank 24 via each exhaust heat recovery circuit 19, 20, and 21, and the liquid in the liquid storage tank 24 is heated. , in a waste heat utilization device with a liquid storage tank for a plurality of engines, one liquid storage tank 24 is provided for a plurality of waste heat extraction parts 15, 16, 17 of a plurality of engines 11, 12, 13. The liquid storage capacity of this one liquid storage tank 24 is the same as that of the plurality of exhaust heat extraction parts 15, 16, 1 of the plurality of engines 11, 12, 13.
The capacity is set to correspond to the total amount of heat of each exhaust heat taken out from engine 7, and the amount of heat of each engine exhaust heat taken out from multiple exhaust heat extraction parts 15, 16, and 17 of multiple engines 11, 12, and 13. The configuration is such that all of the liquid is supplied to one liquid storage tank 24.

(Invention of Claim 2) For example, as shown in FIG. 1, three or more engines 11, 12, 13 are used, and all these engines 11, 12, 13 are operated alternately with two or more engines. The exhaust heat extraction section 15 of all engines 11, 12, 13 is
The exhaust heat from each engine 16 and 17 is supplied to one liquid storage tank 24 through each exhaust heat recovery circuit 19, 20, and 21, so that the liquid in the liquid storage tank 24 can be heated. Each of the exhaust heat recovery circuits 19, 2o, and 21 is configured such that the heat medium circulating therein can be switched between a supply state and a stop state by means of one stage of supply/stop switching means 27, 28, and 29. The stop switching means 27, 28, and 29 are connected to the switching operation devices 31 and 29.
32, 33 and switching control devices 35, 36, and 37, each engine 11, which is in operation, is connected to the engine operation/stop detection means 39, 40, 41 and the engine temperature detection means 43 in a controllable manner. 12, the switching control devices 135 and 36 are activated based on the engine operation/stop detection means 39 and 40 detecting the engine operation state.
The supply/stop switching means 27 and 28 are driven to the supply state via the switching operation devices f131 and f132, and for the engine 13 that is not operating, the detected temperature detected by the engine temperature detection means 43 is changed to the engine temperature. 13
Depending on whether the starting temperature is higher or lower than the set temperature for starting, the supply/stop switching means 29 is controlled and driven in two ways, a stop state and a supply state, and when the temperature is high, it is controlled and driven to a stop state. Therefore, it was configured to be controlled and driven to the supply state when the temperature is low.

(Invention of Claim 3) For example, as shown in FIG. The engine exhaust heat extracted from the heat extraction parts 65, 66, 67 is transferred to each exhaust heat recovery circuit 69, 70.
- Supplied to one liquid storage tank 74 via 71, and the liquid storage tank 7
The heating medium circulating in the exhaust heat recovery circuit 71 connected to the exhaust heat extraction section 67 of the bank-up engine 63 is supplied to the exhaust heat recovery circuit 71 by means of a supply/stop switching means 79. The supply/stop switching means 79 is connected to the engine operation/stop detection means 91 and the engine temperature detection means 93 via a switching operation device 83 and a switching control device 87 so as to be controllable and driveable. , When the backup engine 63 is in operation, the engine operation/stop detection means 91 detects the engine operation state, and the supply/stop switching means 79 is activated via the switching control device 87 and the switching operation device 83. When the backup engine 63 is in the supply state and the backup engine 63 is stopped, the supply is stopped depending on whether the detected temperature detected by the engine temperature detection means 93 is higher or lower than the set temperature for starting the backup engine 63. The switching means 79 is controlled and driven in two ways, a stopped state and a supply state, and when the temperature is high, it is controlled and driven to the stopped state, whereas when the temperature is low, it is controlled and driven to the supply state. It was configured as follows.

(effect) The invention works as follows.

(Invention of Claim 1) The liquid storage tank 24 is configured to accommodate a plurality of engines 11, 12 (and 13).
), the ratio of the tank surface area to the tank capacity can be made smaller than in the conventional example. Therefore, heat radiation loss from the liquid storage tank 24 can be reduced, and the recovery rate of engine exhaust heat can be improved accordingly.

In addition, piping can be completed by simply connecting the liquid storage tank inlet 24a directly to the water supply pipe and the liquid storage tank outlet 24b directly to the hot water supply pipe, which can reduce the piping cost that requires time and effort to connect the pipes. , requires less piping space.

(Invention of Claim 2) - See Figure 1 For example, when the engine 11 and the engine 12 are in operation and the engine 13 is not operating, the supply/stop switching means 29 for the engine 13 is operated to the stopped state. At the same time, supply/stop switching means 27 and 28 for engines 11 and 12 are provided.
is operated in the supply state, and the liquid stored in the liquid storage tank 24 is heated by exhaust heat from the engines 11 and 12.

When the surface temperature of the engine body of the engine 13 at rest or the temperature of the outside air falls below the set temperature for engine starting, the engine temperature detection means 43 detects this, and
The supply/stop switching means 29 is operated to the supply state via the switching control device 37 and the switching operation device 33. As a result, the high-temperature liquid in the liquid storage tank 24 is distributed to the exhaust heat extraction section 17 of the engine 13 that is inactive, and the engine 13 is heated by the heat dissipation.

As a result, the idle engine 13 can be easily started when replacing the engine 11 or 12.

(Invention of Ill Claim 3) - See Figure 3 For example, when two regular engines 61 and 62 are in operation and one back-up engine 63 is on standby, the power supply for engine 63 is The stop switching means 79 is operated to the stop state, and the liquid stored in the liquid storage tank 74 is heated by exhaust heat from the engines 61 and 62.

When the surface temperature of the engine body of the standby backup engine 63 or the temperature of the outside air drops below the set temperature for starting the engine, this is detected by the engine temperature detection means 9.
3 detects, the switching control device 87 and the switching operation device 83
The supply/stop switching means 79 is operated to the supply state via. As a result, the high-temperature liquid in the liquid storage tank 74 is distributed to the exhaust heat extraction section 67 of the engine 63 on standby, and the heat is released from the engine 63.
is heated. As a result, the standby bank-up engine 63 can be easily started when backing up the failure of the engine 61 or 62.

(Effects of the Invention) The present invention has the following effects because it is configured and operates as described above.

(Invention of Claim 1) Since the ratio of the tank surface area to the tank capacity can be reduced, the heat radiation loss from the liquid storage tank can be reduced, and the recovery rate of engine exhaust heat can be improved accordingly.

In addition, the inlet of the liquid storage tank is connected directly to the water pipe, and
Piping can be completed by simply connecting the liquid storage tank outlet directly to the hot water supply piping, so piping connections do not take much time and piping costs can be reduced. Moreover, the piping space is small.

(Invention of Claim 2) When the temperature such as the surface temperature of the engine body or the outside air temperature of the engine that is inactive falls below the set temperature for starting the engine, the supply/stop switching means is automatically operated to the supply state. As a result, the high-temperature liquid in the liquid storage tank is distributed to the exhaust heat extraction section of the engine that is inactive, and the engine is heated by the heat dissipation.

As a result, the idle engine can be easily started when replacing the running engine.

(Invention of Claim 3) When the temperature such as the surface temperature of the engine body of the standby backup engine or the temperature of the outside air falls below the set temperature for engine starting, the supply/stop switching means is automatically operated to the supply state. . As a result, the high-temperature liquid in the liquid storage tank is distributed to the exhaust heat extraction section of the engine on standby, and the engine is heated by the heat released.

As a result, the standby backup engine can be easily started when backing up a failure in the running engine.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

(First example) 1 and 2 show a first embodiment.

In the overall system diagram shown in Figure 1, three cogeneration devices 1, 2, and 3 are connected to one liquid storage tank (here, a hot water storage tank).
24 in parallel.

These cogeneration systems 1, 2, and 3 are the following 3
Operated in shifts under street conditions. In other words, there are two situations: operating Units 1 and 2 while stopping Unit 3; operating Units 1 and 3 but stopping Unit 2; and operating Units 2 and 3. On the other hand, the first machine is stopped, and the configuration is such that two machines are operated in turn while one machine is put out of operation.

Each cogeneration device 1, 2, and 3 is
Engines 11, 12, 13 and generator 14 inside the soundproof case
・14 and 14 are arranged, each engine 11 and 12
- By driving each generator 14 at 13, power is supplied to an external power load. At the same time, the engine exhaust heat of the heat retained in the engine coolant and the heat retained in the exhaust gas in each engine 11, 12, 13 is transferred from each exhaust heat extraction section 15, 16, 17 to each exhaust heat recovery circuit 19, 20,
The liquid can be supplied to one liquid storage tank 24 via 21.

Each of the above exhaust heat extraction parts 15, 16, and 17 is connected to each engine 1.
The engine coolant in the water jackets 1, 12, and 13 is circulated from the exhaust gas heat exchanger to the heat supply passage 23a of the exhaust heat recovery heat exchanger 23 using a water pump.

In addition, each exhaust heat recovery circuit 19, 20, 21 is connected to a liquid storage tank 24.
The tap water stored in the interior is circulated through the heat receiving flow path 23b of each heat exchanger 23 for exhaust heat recovery by the circulation pump 46 provided in the main outgoing path 45, where the engine exhaust heat is absorbed and transferred from the main return path 47. By returning the water to the liquid storage tank 24, the tap water stored therein is heated. Each exhaust heat recovery circuit 1
9, 20, and 21 have solenoid valves sv1 and 5v2, respectively.
Sv3 and flow rate regulating valves 48, 48, 48 are provided.

The liquid storage tank 24 is configured to meet the demand for hot water supply by supplying tap water introduced from a tap water inlet 24a and heated by engine exhaust heat to the outside from a hot water supply outlet 24b. and,
The liquid storage capacity of the liquid storage tank 24 is the same as that of the two engines 11 and 12 (
or 13) two waste heat extraction parts 15 and 16 (or 17)
By setting the capacity to match the total amount of exhaust heat extracted from the engine, it is possible to compensate for the peak demand for hot water, which fluctuates over time.

The tap water circulating inside each of the above exhaust heat recovery circuits 19, 20, and 21 is controlled by solenoid valves S■1, sv2, and sv.
The supply/stop switching means 27, 28, and 29 consisting of three on-off valve bodies are configured to be able to switch between a supply state and a stop state. In addition, the supply/stop switching means 27-28-29 made of an on-off valve body includes switching operation devices 31, 32, 33 and switching control devices 35, 36, and 33, each consisting of an electromagnetic filter of the electromagnetic valves 5V1-3V2 and Sv3.
Through 37, engine operation/stop detection means 39 and 40
41 and the engine temperature detection means 43 in a controllable manner. The engine temperature detecting means 43 indirectly detects the temperature of the stopped engine by detecting the outside air temperature.

The switching control device 35 includes an electromagnetic contactor A1 for power debt connection.
, an electromagnetic contactor B for alarm output, an electromagnetic contactor P for starting and stopping the pump, and an electromagnetic relay T for temperature detection. Then, the contact 49b of the electromagnetic contactor A1 is connected to the switching operation device 31.
The contact 50b of the electromagnetic contactor B and the coil 51a of the electromagnetic contactor P are connected, and the contact 53b of the electromagnetic relay T1 is connected in parallel with these. In addition, the switching control devices 36 and 37 also operate the electromagnetic contactors A and A1 in the same way as above.
, Magnetic contactor B, ・B8, Magnetic contactor P t ” P
It is equipped with s. And an electromagnetic contactor P for starting and stopping the pump.
, ·P, ·P, are connected in parallel to the circulation pump 46.

The exhaust heat utilization system having the above-mentioned configuration operates as follows in an operating state in which the cogeneration energy exchange devices 1 and 2 are operated and the cogeneration energy exchange device 3 is stopped.

The cogeneration device 1 starts operating according to the following procedure. First, when the engine 11 is started, the start is detected by the engine operation/stop detection means 39, and the generated voltage of the generator 14 driven by the engine 11 increases, indicating that the voltage has been established. Upon detection by a voltage detection means (not shown), the coil 49a of the electromagnetic contactor A is excited and its contact 49b is closed.

As a result, the electromagnetic contactor P is excited, and its contact 51
b opens to drive the circulation pump 46 and open the solenoid valve SVI. Thereby, the tap water in the liquid storage tank 24 is circulated through the exhaust heat extraction part 15 via the exhaust heat recovery circuit 19, and the tap water in the liquid storage tank 24 is heated.

The power generation system 2 is also operated through the same process as described above.

The opening and closing operations of the electromagnetic valves Sv1, SV2, and S3 are summarized as shown in FIG. 2.

That is, first, it is determined whether or not the cogeneration device 1 is operating (S1), and if it is, it is determined whether the operating state of the cogeneration device 1 is normal (S2). When normal, the solenoid valve Svl is opened (S3). If the Sl is determined to be stopped,
If it is determined in S2 that there is an abnormality, the solenoid valve SV1 is closed (S4).

Regarding cogeneration devices 2 and 3, steps S5 to 88 and steps S9 to 312 are performed in the same manner as above.
is controlled based on the steps of

Then, the following operation is automatically performed on the fusier energy injection device 3 whose operation is stopped.

When the outside temperature detected by the engine temperature detection means 43 is higher than the set temperature for starting the engine 13 (for example, 5° C.), the coil 53a of the electromagnetic relay T1 is held in a demagnetized state and its contact 53b is closed. The circuit is opened, and the solenoid valve SV3 is kept closed.

On the other hand, the outside air temperature detected by the engine temperature detection means 43 is the set temperature for starting the engine 13 (for example, 5
℃), coil 5 of electromagnetic relay T,
3a is energized, its contact 53b is closed, and the solenoid valve Sv
3 is opened. As a result, the hot water in the liquid storage tank 24 is passed through the exhaust heat recovery circuit 21 to the exhaust heat extraction section 17, and is radiated from there into the soundproof case. Thereby, the engine 13 is heated and can be started easily.

In addition, the above-mentioned supply/stop switching means 27, 28, and 29 can also be configured with one flow path switching valve instead of being configured with three on-off valve bodies.

In addition, the switching control devices 35, 36, and 37 that operate the supply/stop switching means 27, 28, and 29 are the electromagnetic contactors A1 and A* for power load connection. It is also possible to operate directly with 39, 40, 41.

Furthermore, instead of detecting the outside air temperature, the engine temperature detection means 43 may detect the temperature inside the soundproof case of the cogeneration system, the engine crankcase temperature, and the engine combustion chamber temperature. good.

Further, the engine operation/stop detection means 39, 40, 41 may detect the operating state/stop state of each generator 14.

(Second example) FIG. 3 shows a second embodiment.

This system is equipped with one backup cogeneration device 3 as a standby device for two cogeneration systems 1 and 2 that are constantly operated. If one of the regular cogeneration devices 1 and 2 fails, the backup cogeneration device 3 is automatically started based on the failure detection signal to back up the failed device. There is.

The rest of the structure is almost the same as that of FIG. 1 described above.

That is, each engine exhaust heat extracted from each exhaust heat extraction section 65, 66, 67 of each engine 61, 62, 63 of the cogeneration system 1, 2, 3 is transferred to each exhaust heat recovery circuit 69, 7.
0.71 to one liquid storage tank 74, thereby heating the tap water in the liquid storage tank 74.

The circulating water in the exhaust heat recovery circuit 71 of the backup engine 67 is switched between a supply state and a stopped state by a supply/stop switching means 79 consisting of an on-off valve body of a solenoid valve SV3. This supply/stop switching means 79 is connected to an engine operation/stop detection means 91 and an engine temperature detection means 9 via a switching operation device 83 and a switching control device 87, which are composed of an electromagnetic coil of a solenoid valve Sv3.
3 in a controlled and drivable manner.

When one of the cogeneration devices 1 and 2 is out of order and the backup engine 63 is in operation, the engine operation/stop detection means 91 detects the engine operation state, and the switching is performed. The solenoid valve Sv3 is opened via the control device 87 and the switching device 83 to circulate the tap water in the liquid storage tank 74 to the exhaust heat extraction section 67.

On the other hand, when both cogeneration devices 1 and 2 are operating normally and the backup engine 63 is stopped, the engine temperature detection means 93
Depending on whether the detected temperature is higher or lower than the starting setting (for example, 5° C.) of the backup engine 63, the supply/stop switching means 79 is controlled and driven in two ways: a stop state and a supply state. Ru. When the temperature is high, the solenoid valve Sv3 is kept closed, whereas when the temperature is low, the solenoid valve SV3 is opened and the hot water in the liquid storage tank 74 is supplied to the exhaust heat extraction part 67. is supplied. As a result, the engine 63 is heated and can be started by the customer during backup. (Third Embodiment) FIG. 4 shows a third embodiment.

In this case, two cogeneration systems 1 and 2 are arranged in parallel to one liquid storage tank 24.

FIGS. 5 to 9 show different embodiments, and the third embodiment (see FIG. 4) is modified as follows.

(Fourth example) FIG. 5 shows a fourth embodiment.

A heating circulation circuit 55 is connected to the liquid storage tank 24 . This circulation circuit 55 is provided with a circulation pump 56 and a radiator 57, and the radiator 57 is provided with a heat radiation fan 58.

In this case, the liquid stored in the liquid storage tank 24 may be another type of heat transfer liquid instead of tap water.

(Fifth example) FIG. 6 shows a fifth embodiment.

Name 4 trillion lick 1st stone W menku 1 q, 9 convex l facing
Fist-pulled β candy is configured in a volumetric manner, and has a circulation pump of 75.
- 75 and heat sinks 76, 76 are arranged in series, and both heat sinks 76, 76 are immersed in the liquid storage tank 24.

(6th example) FIG. 7 shows a sixth embodiment.

In this case, the exhaust heat extraction sections 15 and 16 are configured with the respective water jackets of the engines 11 and 12 and an exhaust gas heat exchanger, omitting the heat exchanger 23 for exhaust heat recovery.

Further, a heat radiator 77 is immersed in the liquid storage tank 24.

(Seventh Example) FIG. 8 shows a seventh embodiment.

In this case, the exhaust heat recovery circuits 19 and 20 are respectively equipped with intermediate heat exchangers 97 and 97, and include a first circuit 98 and a second circuit 9.
It consists of 9.

In each of the embodiments described above, an engine installed in a cogeneration device is exemplified, but the present invention can also be applied to an engine installed in other types of engine working machines such as a heat pump device.

[Brief explanation of drawings]

1 to 8 show embodiments of the invention. 1 and 2 show the first embodiment, FIG. 1 is an overall system diagram, and FIG. 2 is a flowchart showing the opening/closing operation state of the solenoid valve. FIG. 3 shows a second embodiment and is a diagram corresponding to FIG. 1. 4 to 8 show the third to seventh embodiments, and are diagrams corresponding to FIG. 1, respectively. FIG. 9 shows a conventional example and is a diagram corresponding to FIG. 4. 11, 12, 13... Engine, 15, 16, 17, 65, 66, 67... Exhaust heat extraction section, 19, 20, 21, 69, 70, 71... Exhaust heat recovery circuit, 24, 74 ...Liquid storage tank, 27, 28, 29, 79... Supply/stop switching means, 31, 3
2・33・83・・Switching operation device, 35・36・37・
87...Switching control device, 39, 40, 41, 91...
Engine operation/stop detection means, 43, 93...Engine noise level detection means, 61, 62...Commonly used engine, 63
...Backup engine.

Claims (1)

[Claims] 1. Each engine exhaust heat extracted from each exhaust heat extraction section (15) (16) (17) of a plurality of engines (11) (12) (13) is transferred to each exhaust heat recovery circuit. (19) (20) (21
) is supplied to the liquid storage tank (24) through the liquid storage tank (24).
In a waste heat utilization device with a liquid storage tank for a plurality of engines configured to heat liquid in the engine, a plurality of waste heat extraction parts (15) of the plurality of engines (11) (12) (13) One liquid storage tank (24) is provided for (16) and (17), and the liquid storage capacity of this one liquid storage tank (24) is the same as that of multiple engines (11), (12), and (13). Multiple exhaust heat extraction parts (
15) (16) (17) The capacity is set to match the total amount of engine exhaust heat taken out from the exhaust heat extracting parts (15) ( 16) An exhaust heat utilization device with a liquid storage tank for a plurality of engines configured to supply all of the heat amount of each engine exhaust heat extracted from (17) to one liquid storage tank (24). Two or three or more engines (11) (12) (13) are used, and all these engines (11) (12) (13) are operated alternately with one or more engines being operated while two or more engines are being operated. The engine exhaust heat taken out from each exhaust heat extraction section (15) (16) (17) of all engines (11) (12) (13) is transferred to each exhaust heat recovery circuit (19). ) (20) (21) to one liquid storage tank (24) to heat the liquid in the liquid storage tank (24), and each exhaust heat recovery circuit (19) (20 ) (21), supply/stop switching means (27) (28)
) (29) is configured to be able to switch between a supply state and a stop state, and the supply/stop switching means (27), (28), and (29) are configured to be able to switch between a supply state and a stop state with 35)
(36) and (37), each engine (11) is connected to the engine operation/stop detection means (39), (40), and (41) and the engine temperature detection means (43) in a controllable manner. ) (12), the switching control devices (35) (36) and the switching operating devices (31) (32 ), the supply/stop switching means (27) and (28) are driven to the supply state, and for the engine (13) which is stopped,
Depending on whether the detected temperature detected by the engine temperature detection means (43) is higher or lower than the starting temperature of the engine (13), the supply/stop switching means (29) is divided into two states: a stopped state and a supply state. The plurality of engines according to claim 1, wherein the plurality of engines are configured to be controlled and driven in a stopped state when the temperature is high, and to be controlled and driven in the supply state when the temperature is low. Exhaust heat utilization device with liquid storage tank. 3. Two or more regular engines (61) (62) and one or more backup engines (63) are used, and each exhaust heat extraction part (65) of all these engines (61) (62) (63) is used. ) (66) (67), each exhaust heat recovery circuit (69) (70) (71
) is supplied to one liquid storage tank (74) through the liquid storage tank (
74) is configured to be able to heat the liquid in the exhaust heat extraction section (67) of the backup engine (63).
The exhaust heat recovery circuit (71) connected to the exhaust heat recovery circuit (71) is configured such that the heat medium circulating therein can be switched between a supply state and a stop state by a supply/stop switching means (79), and the supply/stop switching means (79) , is connected to the engine operation/stop detection means (91) and the engine temperature detection means (93) via the switching operation device (83) and the switching control device (87) so that the backup engine (63) can be controlled and driven. In the operating state, based on the engine operation/stop detection means (91) detecting the engine operation state, the supply/stop switching means ( 79) is driven to the supply state and the backup engine (63) is stopped, the detected temperature detected by the engine temperature detection means (93) is lower than the set temperature for starting the backup engine (63). Depending on whether the temperature is high or low, the supply/stop switching means (79)
is controlled and driven in two ways, a stopped state and a supply state, and when the temperature is high, it is controlled and driven to the stopped state, but when the temperature is low, it is controlled and driven to the supply state. An exhaust heat utilization device with a liquid storage tank for a plurality of engines according to claim 1.