JP3980570B2 - Waste heat recovery device - Google Patents

Description

The present invention relates to an exhaust heat recovery device that recovers exhaust heat of an external device such as a power generation device and reuses the heat.

  In a power generation system that generates power using the rotational force of an engine, in a water-cooled engine, heat is absorbed by the cooling water, and the high-temperature cooling water is radiated by a radiator or the like and then used again to cool the engine. If a waste heat recovery device that absorbs waste heat is installed instead of the radiator, the heat energy of the exhaust heat of the engine can be used effectively.

Prior patent documents relating to such exhaust heat recovery include the following.
JP 2003-282108 A Japanese Patent Laid-Open No. 2003-42539 discloses that the heat of a fuel cell is taken out by a cooling pipe, exhaust heat is recovered by a heat exchanger and stored in a hot water storage tank. Water using a circulation pump is circulated in the cooling pipe and the exhaust heat recovery pipe.

Patent Document 2 discloses that waste heat is recovered by drawing heat of waste water stored in a drain buffer tank into a heat recovery unit by a heat pump cycle.

  By the way, Patent Document 1 discloses exhaust heat recovery as a part of the fuel cell system, and this exhaust heat recovery links the power generation device and the exhaust heat recovery device, and makes the exhaust heat recovery device versatile. It is scarce.

  In the exhaust heat recovery disclosed in Patent Document 2, the exhaust heat recovery is performed from the drain buffer tank, and the drain buffer tank unit is indispensable.

Accordingly, an object of the present invention is to provide an exhaust heat recovery apparatus with improved versatility, regarding exhaust heat recovery from an external device.

In order to achieve the above object, the exhaust heat recovery apparatus of the present invention is an exhaust heat recovery apparatus that absorbs and recovers the exhaust heat of the external device into the fluid, and is disposed in the external device to circulate the fluid. A fluid path for absorbing the exhaust heat of the external device in the fluid; a hot water storage means for storing water heated by the heat of the fluid flowing in the fluid path; and storing the exhaust heat by the water; and A circulation path for returning the water taken out from the lower layer part to the upper layer part of the hot water storage means , the fluid flowing in the fluid path, and the water circulating in the circulation path are circulated, and the heat of the fluid is transferred to the water. Heat exchanging means for exchanging heat ; inlet side temperature detecting means for detecting the inlet side temperature of the fluid entering the heat exchanging means; and outlet side temperature detecting means for detecting the outlet side temperature of the fluid exiting from the heat exchanging means. And a fluid path for circulating the fluid in the fluid path Pump and the circulation path side pump for circulating the water in the circulation path, the heat recovery start threshold value and the exhaust heat recovery stop threshold value with respect to the entering-side temperature of the fluid entering the heat exchange means, said The exhaust heat recovery start threshold value and the exhaust heat recovery stop threshold value are set with respect to the outlet temperature of the fluid exiting from the heat exchange means, and the fluid circulating in the fluid path by operating the fluid side pump If the inlet side temperature is equal to or higher than the exhaust heat recovery start threshold value or the outlet side temperature is equal to or higher than the exhaust heat recovery start threshold value, the exhaust heat recovery is maintained by operating the circulation side pump, The circulating flow rate of the water is controlled according to the detected temperature of the inlet side temperature detecting means or the outlet side temperature detecting means, and the inlet side temperature is less than the exhaust heat recovery stop threshold value or the outlet side temperature is the exhaust temperature. If it is below the heat recovery stop threshold, the previous Circulation roadside pump is stopped to end the exhaust heat recovery, in the exhaust heat in the recovery of the fluid, and a control unit for detecting the temperature of the delivery temperature detection means for controlling said circulation path side pump for optimal temperature It is the structure provided with.

  According to such a configuration, it is possible to control the start and stop of exhaust heat according to the state of heat absorption of the fluid circulated in the external device, and to efficiently recover the exhaust heat into water. Since the state of exhaust heat can be grasped through the temperature of the fluid, it is not necessary to be linked to the direct operation of the external device. In other words, the exhaust heat recovery device can be operated independently of the external device, and efficient exhaust heat recovery is possible. A heat recovery device can be connected to perform exhaust heat recovery.

In order to achieve the above object, the exhaust heat recovery apparatus of the present invention comprises, in the above configuration, temperature detection means for detecting an outlet side temperature of the water exiting from the heat exchange means, and during the exhaust heat recovery, the control The unit may be configured to control the circulation path-side pump so that the detection temperature of the water exiting the heat exchange means becomes an optimum temperature, or a flow rate detection means for detecting a flow rate of the fluid flowing in the fluid path. And during the exhaust heat recovery of the fluid, the control unit obtains a heat exchange heat quantity from the detected temperature of the inlet temperature detection means and the detected flow rate of the flow rate detection means, and is obtained from this heat exchange heat quantity It is good also as a structure which controls the said circulation path side pump to the optimal circulation flow volume .

In order to achieve the above object, the exhaust heat recovery apparatus of the present invention, in the above configuration, has an inlet side temperature detecting means for detecting an inlet side temperature of the water entering the heat exchanging means, and the water exiting from the heat exchanging means. An outlet side temperature detecting means for detecting the outlet side temperature of the fluid, and a flow rate detecting means for detecting a flow rate of the water flowing in the circulation path, and during the exhaust heat recovery of the fluid, the control unit It is good also as a structure which calculates | requires an optimal circulation flow rate from the heat exchange calorie | heat amount calculated | required from the said inlet side temperature of this, the said outlet side temperature, and the detection flow rate of the said flow volume detection means, and controls the said circulation path side pump to this optimal circulation flow rate .

  With such a configuration, if one of the fluid detection temperature, the water detection temperature, the fluid detection flow rate, or two or more of these is used as control information to control the driving of the pump that circulates water, the exhaust heat state Therefore, it is possible to efficiently perform exhaust heat recovery.

In order to achieve the above object, a configuration may be provided that includes a tank for storing the water that has absorbed the heat from the fluid, and the external device may be a power generation device.

  With such a configuration, the following effects can be obtained according to the present invention.

  (1) Since the exhaust heat recovery control according to the exhaust heat from the external device such as the power generator is realized, the control by the operation with the external device is not necessary. It can be used as an exhaust heat recovery device.

(2) It is not necessary to be linked with the operation of the external device, and is configured independently. When the refrigerant of the external device becomes high temperature, the thermal energy of the refrigerant can be recovered.

  An embodiment of the present invention will be described with reference to FIG. FIG. 1 is a diagram showing an outline of an exhaust heat recovery apparatus according to an embodiment of the present invention.

The power generation device 4 constituting the external device of the exhaust heat recovery device 2 uses an engine or the like as a drive source, and generates heat during the power generation. The power generation device 4 absorbs exhaust heat and incorporates a cooling water pipe 6 as a means for cooling the power generation device 4, and a cooling circuit 8 for cooling the power generation device 4 including the cooling water pipe 6 is configured. Has been. The cooling circuit 8 is cooled water W ₁ is circulated as the fluid constituting the refrigerant, cooling water W ₁ which has absorbed heat is outward from往管10 to the exhaust heat recovery device 2, by the exhaust heat recovery apparatus 2 The cooling water W ₁ after the exhaust heat recovery is circulated to the cooling circuit 8 through the return pipe 12. That is, in this embodiment, the exhaust heat recovery device 2 is connected to the cooling water pipe 6 built in the power generation device 4. With such a configuration, the cooling water W _{1 that} has absorbed the exhaust heat of the power generation device 4 is circulated to the exhaust heat recovery device 2 and recovered after the exhaust heat recovery, that is, after the cooling function is recovered, It will circulate. The exhaust heat recovery device 2 is provided with a hot water storage tank 14 as a heat storage means for exhaust heat recovered by heat exchange, and the exhaust heat is stored as high temperature water (hot water).

  The exhaust heat recovery device 2 is provided with a control device 16 for performing exhaust heat recovery control independent of the control of the power generation device 4, and a power source 18 independent of the power generation device 4 is connected to the control device 16. ing. That is, the exhaust heat recovery device 2 and the power generation device 4 are connected only by the cooling circuit 8.

  The hot water storage tank 14 includes a hot water supply circuit 20 that uses high-temperature hot water on the upper layer side in the tank, and a water supply circuit 22 that supplies cold water before heat exchange on the lower layer side, so that high-quality and efficient heat use is provided. Is possible.

  Next, the configuration of the exhaust heat recovery apparatus 2 will be described with reference to FIG. FIG. 2 is a block diagram illustrating a configuration of the exhaust heat recovery apparatus 2.

The exhaust heat recovery device 2 includes a hot water storage tank 14, a control device 16, an exhaust heat recovery heat exchanger 24, and the like, and a cooling circuit 8 is connected to the heat exchanger 24. In the cooling circuit 8, a circulation pump 26 is installed on the power generation device 4 side, a flow rate sensor 28 is installed on the exhaust heat recovery device 2 side, and on the heat input side and heat output side of the heat exchanger 24. As the first temperature detection means, temperature sensors 30 and 32 are installed. The cooling water W ₁ of the cooling circuit 8 is forcibly circulated by a circulation pump 26 installed on the cooling water pipe 6 side, and the circulation flow rate is detected by a flow sensor 28. The temperature sensor 30 detects the temperature of the cooling water W ₁ on the heating input side, and the temperature sensor 32 detects the temperature of the cooling water W ₁ on the heating output side. The circulation pump 26 is driven and controlled on the power generation device 4 side, and when the return temperature of the cooling water W ₁ increases, the power generation device 4 decreases the power generation output or stops the power generation.

A circulation circuit 36 is installed between the heat exchanger 24 and the hot water storage tank 14 as a circulation path for circulating the water W _2. The circulation circuit 36 takes out the water W ₂ from the lower layer of the hot water storage tank 14. In this circuit, the water W ₂ is circulated through the heat exchanger 24 to receive heat from the cooling water W ₁ and then returned to the upper layer of the hot water storage tank 14. The circulation circuit 36 is provided with a circulation pump 38 and a flow rate sensor 40 on the outlet side of the hot water storage tank 14, and a temperature sensor as a second temperature detection means on the heat receiving side and the heat receiving side of the heat exchanger 24. 42 and 44 are installed. The water W _{2 in the} hot water storage tank 14 is forcibly circulated by a circulation pump 38, and the circulation flow rate is detected by a flow sensor 40. The temperature sensor 42 detects the temperature of the water W ₂ on the heat receiving side, and the temperature sensor 44 detects the temperature of the water W ₂ on the heat receiving side.

  A plurality of temperature sensors 46, 48, 50, 52, 54 are installed in the hot water storage tank 14 in order to detect the temperature of the layer portion of the hot water storage. Each temperature from the upper layer portion to the lower layer portion is detected by these temperature sensors 46-54.

  The hot water storage tank 14 is connected to a hot water supply circuit 20 that takes out the high-temperature hot water in the upper layer portion to the outside, and a water supply circuit 22 that supplies water to the lower layer portion. The hot water supply circuit 20 is provided with a temperature sensor 56 for detecting the hot water supply temperature, the water supply circuit 22 is provided with a temperature sensor 58 for detecting the water supply temperature, and a flow rate sensor 60 for detecting the amount of water supply.

  Next, the control device 16 will be described with reference to FIG. FIG. 3 is a block diagram showing an outline of the control device 16.

  The control device 16 includes a CPU, a memory, an I / O, and the like. In order to monitor the control status by temperature, the control device 16 is input with detection outputs from the sensors 46 and 48 described above, and is connected with an input device 62 for setting operating conditions and the like. Yes. The input device 62 includes a keyboard or the like. The output of the control device 16 is applied to the circulation pump 38 and is also applied to the display device 64 as a means for presenting control information. The display device 64 is configured by an LCD display or the like, and displays input information and output information from the input device 62. The display device 64 includes a warning display means by voice. The input information from the input device 62 includes various information such as operation start temperature setting, cooling water return temperature setting, hot water storage temperature setting, etc., and is stored in the internal memory.

  Next, the exhaust heat recovery control will be described with reference to FIG. FIG. 4 is a flowchart showing exhaust heat recovery control.

In this exhaust heat recovery control,
T ₃₀ : temperature detected by the temperature sensor 30 (inlet temperature of the cooling water W ₁ of the heat exchanger 24),
T ₃₂ : temperature detected by the temperature sensor 32 (outside temperature of the cooling water W ₁ of the heat exchanger 24),
T _aH : waste heat recovery start threshold temperature corresponding to the detected temperature T ₃₀ (starting start threshold of the circulation pump 38: first set temperature),
T _bH : Waste heat recovery start threshold temperature corresponding to the detected temperature T ₃₂ (starting start threshold of the circulation pump 38: first set temperature),
T _aL : Waste heat recovery stop threshold temperature corresponding to the detected temperature T ₃₀ (start / stop threshold of circulation pump 38: second set temperature),
T _bL : Exhaust heat recovery stop threshold temperature corresponding to the detected temperature T ₃₂ (start / stop threshold of the circulation pump 38: second set temperature),
T _S : target temperature of the cooling water W ₁
T _SH : upper limit value of the target temperature of the cooling water W ₁ ,
T _SL : Lower limit value of the target temperature of the cooling water W ₁
ΔT _S : temperature width of target temperature of cooling water W ₁ (T _SH −T _SL ),
Tc: optimum return temperature on the external device side,
T ₄₂ : temperature detected by the temperature sensor 42
T ₄₄ : temperature detected by the temperature sensor 44
Tm: the target temperature of the water W _2.

  Therefore, when the control device 16 is energized by turning on the power switch or the like, device initialization or the like is executed (step S1). For this initialization, it is detected whether or not there is a change in the set value (step S2). The setting value is changed by the input device 62, and the setting content is displayed on a liquid crystal display, an LED display, or the like constituting the display device 64. After the change of the set value or if there is no change of the set value, it is determined whether or not exhaust heat is being recovered (step S4).

Whether or not exhaust heat is being recovered can be determined by whether or not the circulation pump 38 is being driven. If it is not in the exhaust heat recovery, if the detected temperature T ₃₀ it is determined whether or not the exhaust heat recovery start threshold value T _aH more (step S5), and a T ₃₀ <T _aH is the detected temperature T ₃₂ It is determined whether or not the exhaust heat recovery start threshold value T _{bH is} exceeded (step S6). If T ₃₂ <T _bH , the exhaust heat recovery cannot be performed, such as when the power generation device 4 is stopped. Return.

If T ₃₀ ≧ T _aH in step S5 or T ₃₂ ≧ T _bH in step S6, the amount of heat required for exhaust heat recovery is supplied to the heat exchanger 24 through the cooling water W ₁ . The circulation pump 38 is activated to start exhaust heat recovery (step S7), and the process returns to step S2.

Further, when it is in the heat recovery (step S4), the detected temperature T ₃₂ it is determined whether or not higher than the upper limit value T _SH target temperature Ts (step S8), and the detected temperature T ₃₂ is the target temperature Ts It is determined whether or not the lower limit value T _SL is lower than the lower limit value T _SL (step S9). If T ₃₂ ≦ T _SL , the rotational speed of the circulation pump 38 is decreased, and the circulation flow rate of the water W _{2 to} the heat exchanger 24 Decrease. Further, in step S8, when it is T ₃₂ ≧ T _SH raises the rotational speed of the circulating pump 38, to the heat exchanger 24 increases the amount of circulating water W _2, thereby, the heat to water W ₂ Increase the exchange amount. In this case, the target temperature Ts has a certain temperature range ΔTs, and the upper limit value and lower limit value thereof are T _SH = Ts + ΔTs and T _SL = Ts−ΔTs.

In such a waste heat recovery, whether the detected temperature T ₃₀ is less than or equal to the heat recovery stop threshold temperature T _aL (step S12), the detection temperature T ₃₂ is the exhaust heat recovery stop threshold temperature T _bL It is determined whether or not (step S13), and if T ₃₀ ≦ T _aL and T ₃₂ ≦ T _bL , the circulation pump 38 is stopped to end the exhaust heat recovery (step S14). Return to S2.

According to such exhaust heat control, when the power generation device 4 is activated, heat is generated therein, so that the circulation pump 26 in the power generation device 4 is activated and the cooling water W that has absorbed the exhaust heat of the power generation device 4 is absorbed. ₁ circulates in the cooling circuit 8. The temperature of the cooling water W ₁ circulating through the cooling circuit 8 is detected by the temperature sensors 30 and 32 as described above, and the exhaust heat recovery operation is started when the above condition is satisfied. As a result, the heat of the cooling water W ₁ of the cooling circuit 8 is heat-exchanged to the water W ₂ circulating through the circulation circuit 36 by the heat exchanger 24, and heat recovery and heat dissipation of the cooling water W ₁ can be performed simultaneously. it can. That is, the cooling capacity of the cooling water W ₁ can be recovered by heat recovery.

In this exhaust heat recovery, when the cooling water W ₁ circulates through the cooling circuit 8 as the power generation device 4 is started, the temperature of the cooling water W ₁ rises. The temperature of the cooling water W ₁ is detected by the temperature sensors 30 and 32, and the detected temperature T ₃₀ is not less than the exhaust heat recovery start threshold value _{Ta aH} or the detected temperature T ₃₂ is not less than the exhaust heat recovery start threshold value T _bH. At this point, the circulation pump 38 is activated, and the water W ₂ is circulated from the lower layer of the hot water storage tank 14 to the circulation circuit 36 and flows back to the upper layer of the hot water storage tank 14 via the heat exchanger 24. . At this time, in the heat exchanger 24, heat exchange with the cooling water W ₁ flowing in the cooling circuit 8 is performed, and cooling of the cooling water W ₁ and heating and hot water storage of the water W ₂ are performed. The rotational speed of the circulation pump 38 may be controlled so that the detected temperature T ₃₂ of the temperature sensor 32 becomes the optimum return temperature Tc of the power generator 4. The optimum temperature Tc may be set in the control device 16 in advance.

In this exhaust heat recovery, the operation of the power generator 4, that is, the state of exhaust heat, is determined by either one of the detected temperatures T ₃₀ and T ₃₂ of the temperature sensors 30 and 32 of the cooling water W ₁ circulating through the power generator 4. Or both. That is, since the operation state of the power generation device 4 appears in the temperature of the cooling water W ₁ , the detected temperatures T ₃₀ and T ₃₂ are the operation information of the power generation device 4. Based on these information, the temperature sensor If the exhaust heat recovery is performed so that the detected temperature T32 of ₃₂ becomes the optimum temperature, cooling of the power generation device 4 and hot water storage in the hot water storage tank 14 can be performed efficiently. Therefore, it is possible to detect the temperature T ₄₄ of the temperature sensor 44 to adjust the rotational speed of the circulation pump 38 so that the above predetermined target temperature Tm, is controlled to the optimum flow rate circulation flow rate L _W2 of the heat receiving side.

In addition, the circulating flow rate of the cooling water W ₁ is detected by the flow rate sensor 28 installed in the cooling circuit 8, and the circulating flow rate L _W1 on the heating side is information indicating the operation status of the power generator 4. Therefore, if this circulating flow rate L _W1 is used as control information, the circulating flow rate L _W2 on the heat receiving side can be set easily and efficiently. For example, since the optimum return temperature Tc of the power generator 4 is known (temperature set in advance in the control unit 16), by the circulation flow rate L _W1 detected by the detected temperature T ₃₀ and the flow sensor 28 of the temperature sensor 30 The amount of heat exchange heat can be known. And heat exchange amount of heat, the detected temperature T ₄₂ of the temperature sensor 42, the heat receiving amount of heat which is estimated from the performance of the heat exchanger 24 has, i.e., the detected temperature T ₄₄ temperature sensor 44 for detecting the heat delivery temperature, the heat-receiving side The circulation flow rate L _W2 of can be calculated. Therefore, the circulation flow rate L _W2 on the heat receiving side can be instantaneously controlled to the optimum circulation flow rate by controlling the rotation speed of the circulation pump 38.

  The features and modifications of each embodiment described above are listed below.

  (1) The power generation device 4 as an external device may be a GE, MGT fuel cell, or the like.

  (2) It can be operated between the power generation device 4 and the exhaust heat recovery device 2 without communication means such as direct electrical signal transmission, and is used for exhaust heat recovery of an external device such as the power generation device 4. be able to.

(3) In the above-described embodiment, the configuration has been described in which when the detected temperature reaches the first set temperature, the process shifts to exhaust heat recovery and stops the exhaust heat recovery when the detected temperature falls below the second set temperature. However, the first and second set temperatures can be changed, and the circulating flow rate L _W2 of the water W ₂ is controlled so that the detected temperature falls within a predetermined temperature range set by the first and second set temperatures. You may do it.

  (4) In the above embodiment, one or both of the detected temperatures of the temperature sensors 30 and 32, one or both of the detected temperatures of the temperature sensors 42 and 44, and either one of the detected flow rates of the flow sensors 28 and 40 Alternatively, both may be used as control information, and the drive of the circulation pump 38 may be controlled using one or more selected from the control information.

  (5) In the above embodiment, the exhaust heat recovery device 2 and the cooling water pipe 6 on the power generation device 4 side have been described as separate configurations, but a water cooling jacket or the like including the cooling water pipe 6 is used as one of the exhaust heat recovery devices 2. You may make it comprise as a part.

  (6) In the above embodiment, the constant temperature range ΔTs is set as the target temperature Ts. However, if the temperature range ΔTs is set to be small or 0, the process of step S9 is not necessary.

  As described above, the most preferred embodiment of the present invention has been described. However, the present invention is not limited to the above description, and is described in the claims or disclosed in the detailed description of the invention. It goes without saying that various modifications and changes can be made by those skilled in the art based on the gist of the invention, and such modifications and changes are included in the scope of the present invention.

  Next, experimental results will be described with reference to FIG. FIG. 5 is a graph showing experimental results.

In the experiment, an exhaust heat recovery device was connected to the cooling circuit of the power generation device as an external device, and a series of operations including start-up, rated operation, and stop was performed. As a result, the power generation device was reliably cooled, And the hot water storage of 60 degreeC or more which is the target of waste heat recovery was obtained. In FIG. 5, To is the outlet temperature of the power generator, Ti is the return temperature of the power generator, Tt is the hot water storage temperature in the hot water storage tank, and L _W1 is the cooling circuit flow rate of the power generator.

The present invention collects exhaust heat from an external device such as a power generator and stores hot water, and can use the hot water for domestic water such as heating and bathing, and can perform exhaust heat recovery regardless of the control of the external device. A highly versatile exhaust heat recovery device can be provided.

It is a figure which shows the outline | summary of the waste heat recovery apparatus which concerns on embodiment of this invention. It is a figure which shows the outline | summary of an exhaust heat recovery apparatus. It is a block diagram which shows the structure of a control system. It is a flowchart which shows exhaust heat control. It is a graph which shows the experimental result of waste heat control.

Explanation of symbols

2 Waste heat recovery device 4 Power generation device (external device)
14 Hot water storage tank 16 Control device (control part)
24 heat exchanger 28 flow sensor (flow rate detection means)
30, 32 Temperature sensor (first temperature detecting means)
36 Circulation circuit (circulation path)
38 Circulating pump 42, 44 Temperature sensor (second temperature detecting means)
W ₁ Cooling water (fluid)
W ₂ water

Claims (5)

An exhaust heat recovery device that absorbs and recovers exhaust heat from an external device into a fluid,
A fluid path disposed in the external device to circulate a fluid and allow the fluid to absorb exhaust heat of the external device;
Hot water storage means for storing water heated by heat of the fluid flowing in the fluid path, and storing the exhaust heat by the water;
A circulation path for returning the water taken out from the lower layer of the hot water storage means to the upper layer of the hot water storage means ;
Heat exchange means for circulating the fluid flowing in the fluid path and the water circulating in the circulation path, and exchanging heat of the fluid with the water ;
An inlet temperature detecting means for detecting an inlet temperature of the fluid entering the heat exchanging means ;
Outlet temperature detection means for detecting the outlet temperature of the fluid exiting from the heat exchange means;
A fluid path side pump for circulating the fluid in the fluid path ;
A circulation path side pump for circulating the water in the circulation path;
Exhaust heat recovery start threshold and exhaust heat recovery stop threshold with respect to the inlet temperature of the fluid entering the heat exchange means, and exhaust heat with respect to the outlet temperature of the fluid exiting the heat exchange means A recovery start threshold value and an exhaust heat recovery stop threshold value are set, and the fluid side pump is operated to circulate through the fluid path so that the inlet temperature of the fluid is equal to or higher than the exhaust heat recovery start threshold value or If the outlet side temperature is equal to or higher than the exhaust heat recovery start threshold, the circulation side pump is operated to maintain the exhaust heat recovery, and the detected temperature of the inlet side temperature detecting means or the outlet side temperature detecting means is maintained. Accordingly, the circulation flow rate of the water is controlled, and the circulation side pump is stopped if the inlet side temperature is lower than the exhaust heat recovery stop threshold value or the outlet side temperature is lower than the exhaust heat recovery stop threshold value. To complete exhaust heat recovery, before the fluid During heat recovery, and a control unit for detecting the temperature of the delivery temperature detection means for controlling said circulation path side pump so that the optimum temperature,
An exhaust heat recovery apparatus comprising: The exhaust heat recovery apparatus according to claim 1,
Temperature detecting means for detecting the outlet temperature of the water exiting from the heat exchanging means, and during the exhaust heat recovery, the control unit is configured so that the detected temperature of the water exiting the heat exchanging means becomes an optimum temperature. The exhaust heat recovery apparatus is characterized by controlling the circulation path side pump . The exhaust heat recovery apparatus according to claim 1,
Flow rate detection means for detecting the flow rate of the fluid flowing in the fluid path is provided, and during the exhaust heat recovery of the fluid, the control unit detects the detected temperature of the inlet side temperature detection means and the detection of the flow rate detection means. An exhaust heat recovery apparatus , wherein a heat exchange heat quantity is obtained from a flow rate, and the circulation path side pump is controlled to an optimum circulation flow rate obtained from the heat exchange heat quantity . The exhaust heat recovery apparatus according to claim 1,
Inlet temperature detecting means for detecting the inlet temperature of the water entering the heat exchange means;
Outlet temperature detecting means for detecting the outlet temperature of the water exiting from the heat exchange means;
A flow rate detecting means for detecting a flow rate of the water flowing in the circulation path;
And during the recovery of the exhaust heat of the fluid, the control unit determines the optimum circulation flow rate from the heat exchange heat quantity obtained from the inlet side temperature, the outlet side temperature of the water, and the detected flow rate of the flow rate detecting means. The exhaust heat recovery apparatus is characterized in that the circulation path side pump is controlled to the optimum circulation flow rate . The exhaust heat recovery apparatus according to claim 1 , wherein the external device is a power generation device.

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