KR101487532B1 - Co-generation system and a method of the same - Google Patents

Abstract

In the cogeneration system and control method thereof according to the present invention, when a no flow rate signal is transmitted when there is a request for hot water supply, the heat radiating fan is driven in advance as soon as the no flow rate signal is transmitted. Therefore, since the heat radiation fan is prepared to secure a normal air flow rate before the heat radiation is performed, the heat radiation can be smoothly performed from the time when the heat radiation path is switched. Therefore, a phenomenon that the temperature of the heat fluid inside the system excessively increases during switching of the heat dissipation furnace can be prevented. Further, there is an advantage that the heat dissipation time can be shortened. Further, since the temperature rise of the heat fluid inside the system is prevented, it is possible to set the temperature of the low temperature bath, that is, the hot water supply target temperature to be higher.

Cogeneration, power generation, hot water supply, heat dissipation

Description

The present invention relates to a cogeneration system and a control method thereof,

The present invention relates to a cogeneration system and a control method thereof, and more particularly, it relates to a cogeneration system and a control method thereof, and more particularly, to a cogeneration system and a control method thereof capable of preventing a temperature rise of a thermal fluid inside a system by shortening a heat radiation time by driving a heat radiation fan in advance The present invention relates to a cogeneration system and a control method thereof.

Generally, a cogeneration system is a system that simultaneously produces power and heat from an energy source. The cogeneration system includes a generator and a drive source for driving the generator. An engine or the like may be used as the driving source. The electric power generated by the generator is supplied to a power consumer.

The heat generated from the driving source includes a low-temperature bath in which hot water is stored. The heat generated in the driving source is supplied to the low-temperature bath so that the temperature of the hot water stored in the low-temperature bath is maintained within the set temperature range. The hot water in the hot water tank is used for heat demand such as heating, steam, and the like. Therefore, an increase in the hot water temperature of the low-temperature bath can be an important factor for supplying the heat required for the heat consumer.

On the other hand, when there is no hot water supply request in the low-temperature bath, the heat generated in the drive source is dissipated through the heat dissipation unit.

However, in the cogeneration system according to the related art, since the predetermined time is required for the heat-radiating fan to reach the normal operation upon switching from the hot water supply to the heat-radiating furnace, the temperature of the thermal fluid inside the system increases when the heat- . The maximum temperature of the low-temperature bath is determined according to the degree of temperature rise of the thermal fluid inside the system, so there is a limit to raising the temperature of the low-temperature bath.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a cogeneration system and a control method thereof that can prevent a temperature rise of a thermal fluid inside a system by reducing the heat radiation time by previously driving the heat radiation fan.

A cogeneration system according to the present invention includes a drive source for driving a generator and generating heat, a hot water supply unit for receiving heat generated from the drive source, a heat dissipation unit for dissipating heat generated from the drive source, A flow rate sensor for sensing a flow rate of water circulating through the hot water supply unit; and a flow rate sensor for detecting a flow rate of hot water supplied from the hot water supply unit to the hot water supply unit, And a control unit for driving the heat dissipation unit before the switching unit switches the flow path to the heat dissipation unit when the flow rate sensor transmits the no flow rate signal.

Further, in the present invention, the heat dissipation unit includes a heat dissipation heat exchanger and a heat dissipation fan, and the control unit drives the heat dissipation fan when the no-flow signal is transmitted and the hot water supply request is received.

Further, in the present invention, when the heat dissipation unit is driven, the drive source operates normally in accordance with the required load.

In addition, in the present invention, the controller controls the switching unit so that heat generated from the driving source is supplied to the heat dissipating unit, when the no flow rate signal continues for a predetermined preset time during driving of the heat dissipating unit.

The control method of the cogeneration system according to the present invention further includes a step of detecting a hot water supply request from the hot water supply unit, a step of sensing a flow rate of water circulating through the hot water supply unit, A heat dissipating unit operating step of operating the heat dissipating unit in advance when the no flow rate signal is transmitted in the flow rate sensing step and a heat dissipating unit operating step in which when the no flow rate signal continues for the set time during the operation of the heat dissipating unit, And a flow path switching step of switching the flow path so as to be sent to the heat dissipation unit.

Further, in the present invention, the heat radiating fan is operated in advance in the step of operating the heat radiating unit.

Further, in the present invention, when the heat-radiating fan operates, when the flow rate sensing signal is transmitted in the flow rate sensing step, the operation of the heat-radiating fan is stopped.

Further, in the present invention, when there is a hot water supply request in the hot water demand sensing step and a flow-presence signal is transmitted in the flow sensing step, the flow path is switched so that heat generated from the drive source is supplied to the hot water supply unit.

Further, in the present invention, when the heat-radiating fan is operated, the drive source controls to operate normally in accordance with the required load.

In the cogeneration system and control method thereof according to the present invention, when a no flow rate signal is transmitted when there is a request for hot water supply, the heat radiating fan is driven in advance as soon as the no flow rate signal is transmitted. Therefore, since the heat radiation fan is prepared to secure a normal air flow rate before the heat radiation is performed, the heat radiation can be smoothly performed from the time when the heat radiation path is switched. Therefore, a phenomenon that the temperature of the heat fluid inside the system excessively increases during switching of the heat dissipation furnace can be prevented. Further, there is an advantage that the heat dissipation time can be shortened. Further, since the temperature rise of the heat fluid inside the system is prevented, it is possible to set the temperature of the low temperature bath, that is, the hot water supply target temperature to be higher.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a schematic configuration diagram of a cogeneration system according to an embodiment of the present invention, and FIG. 2 is a control block diagram of the cogeneration system shown in FIG.

1, the cogeneration system includes a chassis 1 forming an outer appearance, a generator 2 disposed inside the chassis 1, and a generator 2 disposed inside the chassis 1, 2), a heat consumer for receiving heat generated from the drive source, and a heat dissipation unit for dissipating heat generated from the drive source.

The generator (2) is connected to an output shaft of the drive source to produce a rotating electric power of the output shaft. The electric power generated by the generator 2 is directly supplied to a power consumption device such as a lighting in a building or a household appliance through a power line or is stored in a battery 3 installed in the chassis 1, To the power consuming device. Between the generator (2) and the power consuming device, a power load sensing part (4) for sensing a power load of the power consuming device is provided.

The driving source may be a fuel cell, an engine 5, or the like. Hereinafter, in the present embodiment, it is assumed that the drive source is the engine 5.

The engine 5 is driven by fossil fuel such as gas or petroleum to drive the generator 2. The engine 5 is provided with a fuel supply pipe 6 through which fuel is supplied to the engine 5, an intake pipe 7 through which air is sucked into the engine 5, And an exhaust pipe 8 through which the gas passes is connected.

The fuel supply pipe (6) is provided with a fuel control solenoid valve (9) for regulating the supply of fuel.

An exhaust gas heat exchanger (10) is installed in the exhaust pipe (8) to recover the exhaust gas heat of the engine (5). In the present embodiment, two exhaust gas heat exchangers 10 are provided.

On the other hand, the engine 5 has various operation modes according to the heat load of the electric power unit or the heat consumer of the electric power consumption appliance. That is, an engine load corresponding operation mode in which the electric power produced by the generator is supplied to the electric power consuming device or the heat generated from the engine 5 is transmitted to the heat consumer, and the electric power produced by the electric generator 2 An engine no-load operation mode in which the heat generated by the engine 5 is not delivered to the heat consumer, and an engine stop mode in which the engine 5 is not operated.

The amount of fuel supplied to the engine 5 differs according to the operation mode. In the engine load corresponding operation mode, fuel corresponding to at least one of a power unit and a heat load is supplied. The engine no-load operation mode is supplied with less fuel than in the engine load corresponding operation mode. The engine stop mode is not supplied with fuel to the engine 5.

In order to supply the fuel as described above, the opening degree of the fuel control solenoid valve 9 is determined in accordance with the load in the engine load corresponding operation mode, and in the engine no-load operation mode, do. In the engine stop mode, the fuel control solenoid valve 9 is closed.

The engine 5 is connected to a heat fluid circulation passage 20 for circulating the heat generated in the engine 5.

The heat consumer includes a hot water supply unit 30 that receives the heat generated from the engine 5 and supplies hot water into the building or an air conditioner that cools the interior of the building by receiving heat generated from the engine 5 It is possible. Hereinafter, in the present embodiment, it is assumed that the heat consumer is the hot water supply unit 30.

 The hot water supply unit 30 includes a low temperature bath 31 in which water is stored, a hot water supply channel 32 branched from the heat fluid circulation channel 20, and a hot water heat exchanger And a water circulation flow path 34 connecting the low temperature bath 31 and the hot water heat exchanger 33 to receive heat from the hot water heat exchanger 33.

The low temperature bath 31 is provided with a temperature sensing unit 35 for sensing the temperature inside the low temperature bath 31 and a temperature setting unit 36 for setting the hot water temperature target of the low temperature bath 31 by the user do. The detected temperature sensed by the temperature sensing unit 35 and the preset temperature set in the temperature setting unit 36 are transmitted to the control unit 60, which will be described later. If the detected temperature is less than the lower limit value of the set temperature (for example, 50 DEG C), the control unit 60 determines that there is a hot water supply request. If the detected temperature is equal to or higher than the upper limit value of the set temperature (for example, 60 DEG C), the controller 60 determines that there is no hot water supply request.

The temperature sensing part 35 may be provided inside the low-temperature bath 31 and may be installed at the outlet of the low-temperature bath 31 in the water circulation channel 34.

The water circulation flow path 34 is provided with a water supply pump 37 for circulating water to the low temperature bath 31 and the hot water heat exchanger 33.

The water circulation flow path 34 is provided with a flow rate sensor 38 for sensing the flow rate of water circulating on the water circulation flow path 34. The flow rate sensed by the flow sensor 38 is transmitted to the controller 60, which will be described later. When the flow rate detected by the flow rate sensor 38 is less than the predetermined set flow rate, the flow rate sensor 38 transmits a no flow rate signal to the controller 60. If the sensed flow rate is equal to or greater than the set flow rate, a flow rate signal is transmitted to the controller 60.

The heat dissipation unit 40 includes a heat dissipation path 41 branched from the heat fluid circulation path 20 and a heat dissipation heat exchanger 42 disposed on the heat dissipation path 41.

The heat radiating heat exchanger 42 can cool the heat of the heat fluid by the cooling water such as water in a water-cooled manner, and can also be cooled in air by air. Hereinafter, in the present embodiment, it is assumed that the heat fluid is exchanged with the outside air and the heat of the heat fluid is cooled by air-cooling. A heat-radiating fan 43 for blowing outside air to the heat-radiating heat exchanger 42 is disposed around the heat-radiating heat exchanger 42.

The cogeneration system further includes a switching unit for switching the flow path so that heat generated from the engine 5 is supplied to either the hot water supply unit 30 or the heat dissipation unit 40. The switching portion is a three-way valve (44) provided at a point where the hot-water flow path (32) and the heat-radiating flow path (41) are branched from the heat-fluid circulation path (20).

The heat fluid circulation passage 20 includes a first flow path 21 connecting the outlet side of the engine 5 and the three-way valve 44, a hot water flow path 32 and a heat radiation path 41 A second flow path 22 connected to the exhaust gas heat exchanger 10 side from the merged summing point 25 and a second flow path 22 for guiding the heat fluid that has passed through the exhaust gas heat exchanger 10 to the engine 5 And three flow paths 23. The second flow path 22 is provided with a heat fluid circulation pump 24 for circulating and pumping the heat fluid.

The cogeneration system includes a control unit 60 for controlling the three-way valve 44 and the heat radiating fan 43. The control unit 60 controls the three-way valve 44 and the heat radiating fan 43 through the values transmitted from the temperature sensing unit 35, the temperature setting unit 36 and the flow sensor 38, do.

That is, the control unit 60 turns on the heat radiating fan 43 as soon as there is a hot water supply request and the no flow rate signal is transmitted from the flow sensor 38. The predetermined time is required until the heat radiation fan 43 is turned on and the normal air flow rate can be secured. Therefore, the heat radiation fan 43 is turned on before the heat radiation is performed. At this time, the control unit 60 controls the engine 5 to operate normally in accordance with the required load. That is, the engine 5 operates in the load corresponding operation mode.

If the no flow rate signal continues for the set time while the heat radiating fan 43 is turned on, the controller 60 determines that there is no hot water flow rate. That is, even if there is a request for hot water supply, if there is no flow rate of water circulating between the hot water heat exchanger 33 and the low-temperature water tank 31, it is determined that there is no hot water flow rate to be heat-exchanged in the hot water heat exchanger 33. The control unit 60 controls the three-way valve 44 so that the heat generated from the engine 5 is supplied to the heat-radiating flow path 41.

On the other hand, when the control unit 60 has a hot water supply request and a flow rate signal is transmitted from the flow rate sensor 38, it determines that there is a hot water flow rate. Therefore, the heat radiating fan 43 is turned off, and the three-way valve 44 is controlled so that the heat generated in the engine 5 is supplied to the hot water flow path 32.

3 is a flowchart showing a control method of the cogeneration system according to the embodiment of the present invention.

In the control method of the cogeneration system according to the present embodiment, first, a hot water supply request sensing step for sensing a hot water supply request from the hot water supply unit 30 is performed.

In the hot water supply request sensing step, the temperature sensing unit 35 senses the temperature inside the low-temperature bath 31. (S1) The sensed temperature is transmitted to the controller 60. [ Further, the user can set the desired hot water supply target temperature in the temperature setting unit 36. [

(S2) If the sensed temperature is lower than the lower limit of the preset temperature (for example, 50 DEG C), the control unit 60 controls the temperature of the inside of the low- It is judged that it is necessary to raise the temperature. That is, the controller 60 determines that there is a hot water supply request (S3)

On the other hand, if the sensed temperature is equal to or higher than the upper limit value of the set temperature (for example, 60 ° C), the control unit determines that it is not necessary to raise the internal temperature of the low- That is, the controller 60 determines that there is no hot water supply request (S4)

After the presence or absence of the hot water supply request is determined as described above, the flow rate sensing step is performed. In the flow rate sensing step, the flow rate of water circulating in the water circulation channel 34 is sensed. In the flow rate sensing step, the flow rate sensor 38 senses the flow rate on the water circulation channel 34 and transmits it as a signal to the controller 60. (S5) (S6) At this time, if the sensed flow rate sensed by the flow sensor 38 is less than the preset stored flow rate, the flow rate sensor 38 transmits a no flow rate signal (S7).

On the other hand, when the detected flow rate detected by the flow rate sensor 38 is equal to or greater than the set flow rate, the flow rate sensor 38 transmits a flow rate signal. (S8)

The control unit 60 determines that there is no hot water supply flow rate if the hot water supply request is not detected in the hot water demand sensing step and the detected flow rate is less than the set flow rate (S14). The heat generated by the engine 5 is dissipated through the heat radiating heat exchanger 42. (S15) In other words, in this case, there is no request for hot water supply, Since the flow rate of the water circulating through the water circulation channel 34 is almost zero, the control unit 60 directly controls the system by the heat radiation operation.

On the other hand, if there is no hot water supply request in the hot water supply request sensing step and the detected flow rate is equal to or higher than the set flow rate, the control unit 60 transmits a flow rate signal. (S9), it is determined that there is a flow rate of hot water supply (S10). That is, the temperature inside the low-temperature bath is lower than the set hot water target temperature but the water circulating flow path 34 is circulated It is determined that there is a flow rate of hot water to be heat-exchanged in the hot water heat exchanger (33). In the present embodiment, it is assumed that the set time is 10 seconds.

If it is determined that there is a flow rate of hot water, the heat generated in the engine 5 must be transferred to the hot water heat exchanger 33. Therefore, the control unit 60 controls the three-way valve 44 to open the hot water supply flow path 32 and shield the heat radiation flow path 41. (S11) The heat generated in the engine 5 And is supplied to the hot water heat exchanger (33) through the hot water flow path (32).

The control unit 60 determines that there is a hot water supply flow rate when there is a hot water supply request in the hot water demand sensing step and the detected flow rate is equal to or higher than the set flow rate. The heat generated by the engine 5 is supplied to the hot water heat exchanger 33. (S11) In other words, in this case, there is a hot water supply request And the flow rate of the water circulating through the water circulation flow path 34 is sufficient, the control unit 60 directly controls the system by the hot water supply operation.

On the other hand, if there is a hot water supply request in the hot water demand sensing step and the detected flow rate is less than the set flow rate, the control unit 60 transmits a no flow rate signal. (S7) When the no flow rate signal is transmitted, The fan 43 is turned on at step S12. That is, before the heat radiation is performed, the heat radiation fan 43 is turned on in advance so that the heat radiation fan 43 is prepared to secure a normal air flow rate. At this time, the engine 5 is normally operated in response to the required load.

(S13). If the no-flow-rate signal continues for 10 seconds, the control unit 60 determines whether the flow-rate-free signal continues for a predetermined time, i.e., 10 seconds, while the heat-radiating fan 43 is turned on. It is determined that there is no hot water flow rate (S14). That is, the hot water tank 31 is lower in temperature than the set hot water target temperature, It is determined that there is no flow rate of the hot water to be heat-exchanged in the hot water heat exchanger.

Therefore, the control unit 60 controls the three-way valve 44 to block the hot water flow path 32 and open the heat radiation path 41. (S15) When the heat radiation path 41 is opened, The heat generated in the engine 5 is supplied to the heat radiating heat exchanger 42 through the heat radiating flow path 41. In the heat-radiating heat exchanger (42), the heat is dissipated by being cooled by the outside air blown by the heat-radiating fan (43). Here, when the no flow rate signal is first transmitted, since the heat radiation paddle 43 has been operated in advance, the heat radiation fan 43 has secured a normal air flow rate. Therefore, the heat dissipation can be performed more quickly.

On the other hand, if the no flow rate signal does not continue for 10 seconds while the heat radiating fan 43 is operated and the flow rate signal is transmitted, the controller 60 determines that there is a flow rate of hot water supply. Therefore, the control unit 60 stops the operation of the heat-dissipating fan 43. The control unit 60 controls the three-way valve 44 to open the hot water flow path 32 and shield the heat radiating flow path 41.

As described above, in the present embodiment, when there is no hot water supply request and the no flow rate signal is transmitted, the controller 60 determines that there is no hot water supply flow rate, and immediately controls the system to the heat radiation operation.

On the other hand, when there is a hot water supply request and the no flow rate signal is transmitted, the controller 60 operates the heat radiating fan 43 once. That is, after the heat radiating fan 43 is operated in advance and the heat radiating fan 43 is prepared to secure a normal air flow rate, it is checked whether the no flow rate signal continues for 10 seconds. That is, it is possible to more accurately determine whether or not there is a flow rate of the hot water supply. Further, even if it is determined that there is no hot water flow rate after the above-mentioned 10 seconds have elapsed, since the heat radiation fan 43 has been operated in advance, the heat radiation can be smoothly performed as soon as the heat radiation operation is started. Therefore, it is possible to prevent the temperature of the heat fluid circulating through the system from rising when the heat radiator is switched from the hot water supply. Also, the heat dissipation time can be shortened.

In addition, since the temperature of the circulating heat fluid can be prevented from rising excessively, the temperature of the low-temperature bath 31, that is, the hot water supply target temperature can be set higher.

1 is a schematic block diagram of a cogeneration system according to an embodiment of the present invention.

2 is a control block diagram of the cogeneration system shown in FIG.

3 is a flowchart showing a control method of the cogeneration system according to the embodiment of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS Fig.

2: generator 5: engine

20: thermal fluid circulation flow path 30:

31: low-temperature bath 32: hot water supply channel

33: Hot water heat exchanger 38: Flow sensor

40: heat dissipating unit 41:

42: heat radiating heat exchanger 44: three-way valve

Claims (9)

A driving source for driving the generator and generating heat; A hot water supply unit for receiving heat generated from the driving source; A heat dissipation unit for dissipating heat generated from the driving source; A switching unit for switching a flow path so that heat generated from the driving source is supplied to either the hot water supply unit or the heat radiation unit; A flow rate sensor disposed in the hot water supply unit for sensing a flow rate of water circulating through the hot water supply unit; And a control unit for driving the heat dissipation unit in advance before the switching unit switches the flow path to the heat dissipation unit when there is a hot water supply request from the hot water supply unit and a flow rate no signal is transmitted from the flow rate sensor. The method according to claim 1, Wherein the heat dissipation unit includes a heat dissipation heat exchanger and a heat dissipation fan, And the control unit drives the heat radiating fan when the flow rate request signal is transmitted and the hot water supply request is received. The method according to claim 1, Wherein the drive source operates normally in response to a required load when the heat dissipation unit is driven. The method according to claim 1, When the flow rate non-existence signal continues for the pre-stored set time during the operation of the heat dissipation unit, And controls the switching unit so that heat generated from the driving source is supplied to the heat radiating unit. A hot water supply request sensing step of sensing a hot water supply request from the hot water supply unit; A flow sensing step of sensing a flow rate of water circulating through the hot water supply unit; A heat dissipating unit operation step of operating a heat dissipating unit that dissipates heat when a hot water supply request is detected in the hot water demand sensing step and a no flow signal is transmitted in the flow sensing step; And a flow path switching step of switching a flow path so that heat generated from a drive source for generating heat is transmitted to the heat dissipation unit when the no flow rate signal continues for a set time during operation of the heat dissipation unit. The method of claim 5, And the heat radiating fan is operated in advance in the operation of the heat radiating unit. The method of claim 6, When the heat-radiating fan is operated, if the flow rate signal is transmitted in the flow rate sensing step, And stopping the operation of the heat radiating fan. The method of claim 6, When there is a hot water supply request in the hot water supply request sensing step and a flow rate signal is transmitted in the flow rate sensing step, And the flow path is switched so that heat generated from the drive source is supplied to the hot water supply unit. The method of claim 6, And controlling the drive source to operate normally in accordance with the required load when the heat radiating fan is operated.

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