JPH05126402A - Combination device for feeding heat and electric power - Google Patents

Abstract

PURPOSE:To obtain a combination device for feeding heat and electric power, which is small in size and has high performance, and with which surplus power can be utilized effectively. CONSTITUTION:The subject device has a generator 5 to be driven by an engine 4, a power controller 50 for controlling a generation output to be outputted by the generator 5, and electric utilities 53 connected to the power controller 50. Further, said device comprises an engine cooling water circulating path 7 adapted to cool cooling water for the engine 4, a hot water heat exchanger 71 provided in said path, and a hot water circulating path 8 provided between a hot water storage tank 91 and the hot water heat exchanger 71. An electric heater 1 is interposed on the way of the hot water circulating path 8 and, in the power controller 50, a power detector 2 for detecting surplus power is provided between the electric heater 1 and the electric utilities 53. In addition, a heater output controller 3 for supplying surplus power detected by the power detector 2 to the electric heater 1 is provided between the electric heater 1 and the power detector 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a compact and high-performance combined heat and power supply device which can effectively utilize surplus power.

[0002]

2. Description of the Related Art In recent years, a cogeneration system (cogeneration unit) uses electric power generated by a generator (power generation output R) in stores and homes, and heats cooling water and exhaust gas associated with driving an engine and a generator. It is becoming widespread as a relatively small hot water supply system that effectively uses water. As shown in FIG. 5, the combined heat and power supply device includes a power generator 5 driven by an engine 4, a power control device 50 for controlling the power output by the power generator 5, and an electric power control device 50. Electrically connected utility 53
Have and. Further, the power control device 50 has a central processing unit (CPU) 51 and an engine control circuit 52.

Further, the above combined heat and power supply system includes an engine cooling water circulation circuit 7 for circulating cooling water for the engine 4 by a cooling water pump 73, and a hot water heat exchanger 7 provided in this circuit.
1 and an exhaust gas heat exchanger 74. The combined heat and power supply device has a hot water storage tank 91 for storing hot water heated by the hot water heat exchanger 71, and a hot water circulation circuit 8 provided between the hot water storage tank 91 and the hot water heat exchanger 71. ..

The hot water storage tank 91 has a water pressure reducing valve 92. The hot water circulation circuit 8 is
Hot water circulation pump 81, the hot water heat exchanger 71, a mixing valve 82, a hot water circuit switching solenoid valve 83, and a faucet 84.
It has a hot water flow switch 85 and a hot water sensor 86. In the combined heat and power supply device, as shown in FIGS. 5 and 6, the generator 5 driven by the engine 4 generates electricity. Then, about 30% of the primary energy generated from the fuel used for the engine 4 is used as the power generation output R in the electric utility 53 of a factory, a home, a store or the like.

The cooling water which has cooled the engine 4 and has been raised in temperature is used to heat the hot water by a hot water heat exchanger 71 provided in the engine cooling water circulation circuit 7 as shown in FIG. .. Energy equivalent to about 40% of the primary energy is used for this. In addition, FIG.
As shown in (1), about 20% of the primary energy amount is effectively used as a heat source for hot water supply by the heat of the exhaust gas 630 generated from the engine 4. About 10% of the primary energy is radiated as unused energy.

Further, the generator 5 has a 4-pole motor, and its rotation speed is about 1500 to 1800 rpm (times / cycle).
Min.) Is controlled by the engine control circuit 52 in the power control device 50. With this, 50
Alternatively, a current having a frequency of 60 Hz is generated, and is used as a light source or a power source for the electric utility 53 in a factory, a store, a home or the like. The heat of the exhaust gas 630 is recovered by the exhaust gas heat exchanger 74 and is effectively used for hot water supply. However, hot water is not required and the hot water heat exchanger 71
When the cooling of the engine cooling water is insufficient, the three-way valve 72 operates to cool the engine 4 and the exhaust gas 63.
The heat supplied by the 0 is the engine cooling water circulation circuit 7
In, the heat is radiated to the outside by the radiator 61 and the blower 62 or the exhaust gas treatment device 63 (see FIGS. 5 and 6).

On the other hand, the hot water is the hot water storage tank 9
It can be stored in 1. The water temperature T of the hot water in the hot water storage tank 91 is detected by the hot water sensor 86. When the temperature of the hot water becomes equal to or lower than the set temperature T _w , the hot water circulating pump 81 moves the hot water as shown by an arrow, and the hot water circulating circuit 8
Is circulated inside. Then, it is heated by the hot water heat exchanger 71. Next, the heated warm water is stored again in the warm water storage tank 91. The hot water is detected by the hot water sensor 86, and when it reaches the set temperature T _w ,
The hot water circulation pump 81 stops.

When hot water is used, the water pressure reducing valve 92 operates. As a result, the circuit from the water pressure reducing valve 92 to the faucet 84 is maintained at an appropriate pressure (for example, about 0.9 kg / cm). In this state, by opening the water faucet 84, hot water having a predetermined temperature T _w can be used.

[0009]

However, as shown in FIG. 6, in the above combined heat and power device, the thermoelectric ratio (Q / R), which is the ratio of the power generation output R and the hot water supply output Q, is constant (60/3).
0). On the other hand, the generated power constantly fluctuates depending on the demand amount in the electric utility 53. Therefore, when the amount of electric power for hot water supply becomes small, the hot water supply output Q
However, the hot water supply becomes insufficient and the hot water supply becomes insufficient. That is, when the amount of electric power is reduced, the output of the engine 4 is reduced, so that the temperature of engine cooling water is reduced. Therefore, the amount of heat supplied to the hot water heat exchanger 71 decreases. Therefore, when the power generation output R is large, it is necessary to increase the hot water supply output Q as much as possible to obtain a large amount of hot water. Therefore, it is necessary to prepare a relatively large hot water storage tank 91 and store hot water in it. Therefore, in this method, the combined heat and power supply device inevitably needs to be large in size, and a large installation place is required.

Therefore, in order to solve the above problem, it has been proposed to arrange a booster heater device on the downstream side of the hot water circulation circuit for the purpose of supplementing the shortage of the power generation output R (see, for example, Japanese Patent Laid-Open No. Hei 1 (1999) -1). -296042). However, in the above proposal, the booster heater device is composed of a non-conductive tubular body made of a ceramic material or a plastic material.

Therefore, the booster heater device inevitably consumes a large amount of heat, and as shown in the above publication, must use a high voltage (400 to 3000 Volt) power source. Therefore, in the above-mentioned combined heat and power device, a normal voltage (for example, 100 to 200 Volt) is used.
Can not use the power of. Therefore, for home use,
The above-mentioned conventional technique cannot be applied to a comparatively small heat and power cogeneration device used for business use. Therefore, the above-mentioned conventional technique is not practical. In addition, there is no control of the thermoelectric ratio to solve the shortage of hot water supply. The present invention has been made in view of such conventional problems, and an object of the present invention is to provide a compact and high-performance combined heat and power supply device that can effectively use surplus power.

[0012]

The present invention comprises a generator driven by an engine, a power control device for controlling the electric power output by the generator, and an electric utility connected to the power control device. Between the engine cooling water circulation circuit for cooling the engine cooling water, the hot water heat exchanger provided in the engine cooling water circulation circuit, the hot water storage tank, and the hot water storage tank and the hot water heat exchanger. In the combined heat and power supply device provided with the hot water circulation circuit provided in the above, an electric heater is interposed in the hot water circulation circuit, and the power control device has power for detecting surplus power with the electric utility. A heater output controller for supplying a surplus power detected by the electric power detector to the electric heater is provided between the electric heater and the detector. In cogeneration apparatus characterized and.

What is most noticeable in the present invention is that an electric heater is provided in the hot water circulation circuit, an electric power detector is provided between the electric power controller and the electric utility, and an electric heater is provided between the electric power controller and the electric heater. In addition, a heater output controller is provided in order to effectively use the surplus power P to heat the hot water. As the hot water heat exchanger, for example, a double pipe type or multi-plate type heat exchanger is used.

The power detector is for always detecting the power value (power generation output R) generated by the generator and detecting the surplus power P not used in the electric utility.

The heater output controller is for supplying the surplus electric power P detected by the electric power detector to the electric heater. Further, as the electric heater,
For example, there are an electric heater with a built-in hot water circuit, a pipe surface contact type electric heater, and the like.

In the electric heater, the heater output controller calculates the heater output value H based on the power consumption value W detected by the power detector and the water temperature T detected by the water temperature sensor, for example. Control the heater. The power control device has a power detector so as to constantly detect the electric utility power and the surplus power P in the engine control circuit, for example. The surplus power P
Is the surplus power that is not consumed in the electric utility (see FIG. 3). Others are the same as the conventional one.

[0017]

In the present invention, a power detector for detecting the surplus power P is provided between the power control device and the electric utility. Therefore, the output power R output by the generator can be constantly detected.
Here, the power consumption value W is calculated from the detected output power R. A heater output controller for heating hot water is provided between the electric power detector and the electric heater. Therefore, the surplus power P detected by the power detector is
It can be supplied to an electric heater.

Further, an electric heater is provided in the hot water circulation circuit between the hot water heat exchanger and the hot water storage tank. Therefore, the electric heater can effectively utilize the surplus electric power P supplied by the heater output controller to improve the capacity of the hot water supply output Q. That is, the heater output value H effectively used by the electric heater is determined based on the required maximum power generation amount G output by the generator and the power consumption value W detected by the power detector. The power output value H is the surplus power P.

Therefore, the thermoelectric ratio (Q / R), which is the ratio between the power generation output R and the hot water supply output Q, can always be controlled to an optimum value. That is, the thermoelectric ratio is control-determined by constantly detecting the surplus power P and the varying power consumption value W. In addition, the power consumption value W which is constantly fluctuating in the electric utility and the heater output value H are controlled and determined, and the maximum power generation amount G required by the constant power generator is controlled and determined.
The power value generated by the generator is determined. As a result, the required maximum power generation amount G (G ≧ W + H) can be output by the generator.

Therefore, in the combined heat and power supply device of the present invention, the heater output value H is set so that a large hot water supply capacity is always obtained.
Can make a control decision. Therefore, the combined heat and power supply device can always exhibit the maximum hot water supply capacity (thermoelectric ratio). On the other hand, due to the effect of improving the hot water supply capacity, the hot water storage tank can be made smaller and have higher performance than the conventional hot water storage tank.

Further, in the present combined heat and power device, a normal voltage (100 V to 20 V) is used instead of the booster heater device which has to use a high voltage as a conventional auxiliary heat source.
An electric heater using 0 V) can be used. Therefore, a relatively small combined heat and power supply device can be obtained. As described above, according to the present invention, it is possible to provide a compact and high-performance combined heat and power supply device that can effectively use surplus power.

[0022]

EXAMPLE A combined heat and power supply apparatus according to an example of the present invention will be described with reference to FIGS. As shown in FIG. 1, the combined heat and power supply device of the present embodiment includes a power generator 5 driven by an engine 4, a power control device 50 for controlling the power output by the power generator 5, and a power control device 50. It has a CPU 51 and an electric utility 53 connected to. Further, as shown in the figure, the combined heat and power supply apparatus includes an engine cooling water circulation circuit 7 for circulating cooling water for the engine 4, a hot water heat exchanger 71 provided in the engine cooling water circulation circuit 7, and a hot water storage. It comprises a tank 91 and a hot water circulation circuit 8 provided between the hot water storage tank 91 and the hot water heat exchanger 71.

As shown in FIG. 1, the electric heater 1 is interposed in the hot water circulation circuit 8, and the electric utility 53 and the CPU 5 are provided in the electric power controller 50.
1 and a power detector 2 for detecting the surplus power P. Further, as shown in the figure, a heater output controller 3 for supplying the surplus electric power P detected by the electric power detector 2 to the electric heater 1 is provided between the electric heater 1 and the electric power detector 2. It is provided. As the electric heater 1,
An electric heater with a built-in hot water circuit is used. The electric heater 1 has a power consumption value W detected by the power detector 2.
And the value of the water temperature T detected by the water temperature sensor 86,
The heater is controlled by the calculated heater output value H. That is, the electric heater 1 is controlled by the heater output value H to determine whether or not the hot water should be constantly heated.

The power detector 2 is for always detecting the electric power (power generation output R) generated by the generator 5 and detecting the surplus electric power P thereof. In addition, the power detector 2
A current / voltage detection effective value type wattmeter is used for the measurement.
The heater output controller 3 supplies the surplus electric power P detected by the electric power detector 2 to the electric heater 1.
It is for controlling. Also, heater output controller 3
Is electrically connected to the CPU 51, and the CPU 51
Controlled by. As the hot water heat exchanger 71, a heat exchanger for exchanging the cooling water of the engine 4 is used.

The power control device 50 has the power detector 2 so as to constantly detect the power consumption value W for the electric utility 53 and the surplus power P thereof.
Examples of the electric utility 53 include household appliances,
There are lighting appliances, home appliances, and office appliances used in commercial homes, stores, etc. As the hot water storage tank 91, a relatively small hot water tank having a smaller capacity than the hot water storage tank 9 in the conventional heat and power supply device is used. As a result, the combined heat and power supply device can be made compact, the installation area of the hot water storage tank 91 can be reduced (space saving), and the dispositionability can be improved.

As shown in FIG. 3, the surplus power P is also a value (GW) obtained by subtracting the power consumption value W consumed by the electric utility 53 from the maximum power generation amount G generated by the generator 5. .. Thereby, the electric heater 1 heats the hot water by making the most effective use of the constantly changing surplus power P. The electric heater 1 is always controlled by the heater output controller 3 to supply hot water. Others are the same as the conventional one.

Next, the function and effect will be described. First, the basic flow of the combined heat and power supply device according to this example is shown in FIG.
This will be described with reference to the flowchart of FIG. First, the hot water supply set temperature T _w (for example, 65 ° C.) is set by the hot water supply user. In the figure, in step S101, the heater output controller 3 is activated at the same time when the driving of the generator 5 is started. Next, in S102, the power detector 2 reads the power consumption value W.

Next, in S103, the heater output value H is
It is calculated as a value (GW) obtained by subtracting the power consumption value W from the required maximum power generation amount G of the generator 5.
Here, when the heater output value H is larger than (GW) (No), the process proceeds to S104. Then, in S104, the electric heater 1 effectively uses the surplus electric power P to heat the warm water. Then, in S104, when the heater output value is H = GW, the process proceeds to the next S106.

On the other hand, when the heater output value H is smaller than (GW) in S104 (Yes), S10 is selected.
It progresses from 3 to S106. In addition, the surplus power P is controlled and determined according to the power consumption value W, and the hot water is heated by effectively utilizing the surplus power P. Then, in S106, the water temperature T is read by the water temperature sensor 86. In S107, when the water temperature T of the warm water is higher than the maximum value T _WH of the set temperature T _W (for example, 67 ° C.) (Yes), the process proceeds to S108. next,
In S108, the heater output controller 3 reduces the heater output value H by the control unit h, and the process returns to S106.

On the other hand, when the water temperature T is lower than the maximum value T _WH (for example, 67 ° C.) of the set temperature T _{w in} the above S107 (No), the process proceeds to S109. And S10
In 9, when the minimum value of the set temperature T _W of the hot water is lower than T _WL , the process proceeds to S110. In S110, the heater output H is increased by the control unit h, and the process returns to S106. When the condition of T _WL <T <T _WH continues, the above S
Return to 102. Then, the hot water is heated again by the electric heater 1.

The above flow will be described below with reference to FIGS. 1, 3 and 4.
Will be specifically described. In this example, a central processing unit (CP) electrically connected to the power control device 50 is used.
The electric power detector 2 for detecting the surplus electric power P is provided between the U) 51 and the electric utility 53. Therefore, the power generation output R output by the generator 5 can be constantly detected. A heater output controller 3 is provided between the electric heater 1 and the power detector 2.

Therefore, the surplus electric power P detected by the electric power detector 2 can be supplied to the electric heater 1.
Further, depending on the power consumption value W detected by the power detector 2 and the water temperature T detected by the water temperature sensor 86, it is control-determined whether or not to heat up to the set temperature T _w . That is, as shown in FIG. 3, when the power consumption value W is detected by the power detector 2, the heater output value H is calculated by the heater output controller 3 so that the electric heater 1 can be calculated.
Is heater controlled. The heater control referred to here is a control for determining whether or not the warm water should be heated by the electric heater 1 by effectively utilizing the surplus power P.

FIG. 3 shows the relationship between the heater output value H (vertical axis) and the power consumption value W (horizontal axis). Here, if the power consumption value W is detected by the power detector 2, the hot water by the electric heater 1 is whether to warm to the set temperature T _W is determined, is determined. Then, the heater output value H
Is determined. On the other hand, the set temperature T _W is a value determined by the user of hot water according to the purpose of use. For example, when hot water is used for the bath, T _W is set to 65 ° C. There is a case where a large amount of hot water supply is required temporarily and the set temperature T _W cannot be controlled. In this case, the mixing valve 82 operates as follows. That is, as shown in FIG. 1, the mixing valve 82 arranged between the hot water heat exchanger 71 and the faucet 84 operates in the following two modes.

Here, when the hot water is lower than the set temperature T _W , the wax thermostat installed in the mixing valve 82 is activated. As a result, the hot water discharged from the faucet 84 is mixed with the hot water in the hot water storage tank 91, and the temperature is constantly controlled to the set temperature T _W. The series of controls described above is performed by detecting the opening / closing of the faucet 84 by the flow detection sensor 85. As described above, in controlling the electric heater 1 by the heater output controller 3, hot water is always kept at the set temperature T _W ,
The electric heater 1 and the heater output controller 3 are activated.

On the other hand, in the hot water heat exchanger 71, the cooling water circulating in the engine cooling water circulation circuit 7 is
It is activated when it is sent to the hot water heat exchanger 71 by opening 2. All of these controls are performed by the CPU 51. Then, when it becomes necessary to heat the hot water, the hot water heat exchanger 71 is controlled to preferentially heat the hot water.

At this time, the three-way valve 72 detects the water temperature of the hot water, and when the hot water is heated to the set temperature T _W , the cooling water flows to the radiator 61 which is the auxiliary heat radiating means. This is also controlled by the CPU 51. As mentioned above,
In this example, as shown in FIG. 3, the heater output value H is determined while controlling the required maximum power generation amount G and the power consumption value W detected by the power detector 2. As a result, the electric power heater is controlled by the heater output controller 3 and the CPU 51 so that the thermoelectric ratio always becomes the optimum value.

Therefore, the heater output controller 3 detects the constantly changing power consumption value W in the electric utility 53, and at the same time, requires the maximum power generation amount G.
Is controlled to calculate the heater output value H. By this,
The heater output controller 3 and the CPU 51 control and determine which of the hot water heat exchanger 71 and the electric heater 1 should be operated. Therefore, as shown in FIG. 4, the heater output value H is controlled to be determined with respect to the power consumption value W, and the proper thermoelectric ratio is controlled so that the maximum hot water supply capacity is always obtained (the upper chain line portion in the figure). Hot water supply capacity Q). Here, FIG. 4 is a graph showing the relationship between the hot water supply capacity Q and the power consumption value W.

That is, according to this example, when the power consumption value W is small, the surplus power P is effectively used and is used for hot water supply to control the thermoelectric ratio (Q / R). The electric power output by the generator 5 can be effectively utilized to the maximum extent. Further, since the hot water supply capacity can be improved as described above, a small-sized hot water storage tank having a smaller capacity than the conventional hot water storage tank 91 can be used. Therefore, the installability and workability of the hot water storage tank 91 are improved. Further, according to this example, since the electric heater 1 is used instead of the booster heater device as in the conventional example, a normal voltage can be used, and a small combined heat and power supply device can be obtained.

[Brief description of drawings]

FIG. 1 is a circuit diagram of a combined heat and power supply device according to an embodiment.

FIG. 2 is a flowchart of the combined heat and power supply device according to the embodiment.

FIG. 3 is a graph showing a relationship between a heater output value H and a power consumption value W in the example.

FIG. 4 is a graph showing the relationship between the hot water supply output Q and the power consumption value W in the example.

FIG. 5 is a circuit diagram of a conventional combined heat and power supply device.

FIG. 6 is an explanatory view showing a utilization rate of primary generated energy of fuel used for an engine in a conventional combined heat and power supply device.

[Explanation of symbols]

 1. ． ． Electric heater, 2. ． ． Power detector, 3. ． ． Heater output controller, 4. ． ． Engine, 5. ． ． Generator, 50. ． ． Power control device, 53. ． ． Electric utility, 7. ． ． Engine cooling water circulation circuit, 71. ． ． Hot water heat exchanger, 8. ． ． Hot water circulation circuit, 91. ． ． Hot water storage tank,

Claims (1)

[Claims] 1. A generator driven by an engine,
An engine cooling water circulation circuit for cooling the engine cooling water, comprising an electric power control device for controlling the electric power output by the generator and an electric utility connected to the electric power control device, A combined heat and power supply device comprising a hot water heat exchanger provided in an engine cooling water circulation circuit, a hot water storage tank, and a hot water circulation circuit provided between the hot water storage tank and the hot water heat exchanger, the hot water circulation circuit comprising: An electric heater is provided inside the electric power control device, and an electric power detector for detecting surplus electric power is provided between the electric power control device and the electric utility. A combined heat and power supply device comprising a heater output controller for supplying surplus power to the electric heater.