JP4139780B2 - Cogeneration system and electric cooking equipment - Google Patents

Description

  The present invention relates to a cogeneration system configured to be able to supply power to a power load in a grid-connected manner with a commercial power system, and to be able to supply heat energy to a heat load. Regarding generation systems.

Conventionally, energy consumed in ordinary households is supplied in the form of electric power, city gas, etc. from an electric power company or a gas company and is individually consumed. By the way, recently, a distributed energy system aimed at reducing CO ₂ emissions and saving energy has been actively developed and put into practical use, and power is generated in a power consuming area even in ordinary homes, apartment houses, offices, etc. The use of distributed power generation systems is expected to progress rapidly in the future. In particular, gas engine cogeneration systems capable of cogeneration with heat and power are attracting attention because of their high overall energy efficiency because they can effectively use not only electric power but also heat energy generated by the gas engine. As a result of the diversification of energy supply forms in general households, there is room for greatly improving environmental performance such as energy costs and CO ₂ emissions due to the consistency between household energy demand trends and energy supply forms. Occurred.

Therefore, in the past, power supply for electric loads such as electrical equipment was exclusively provided by electric power from commercial power systems such as electric power companies, but by introducing a cogeneration system for home use and grid connection with the commercial power system, In the case of a usage mode in which the shortage of generated power of the cogeneration system is compensated with the power supply from the commercial power system, the cogeneration system can be operated efficiently according to the domestic power demand. Therefore, it has been proposed to perform an operation plan in accordance with the power demand and operate the cogeneration system based on the operation plan (see, for example, Patent Document 1 below).
JP 2003-209994 A

  By the way, the cogeneration system can also supply heat energy by using exhaust heat generated with power generation. Therefore, by effectively using the heat energy, energy utilization efficiency can be further improved. it can. Therefore, in order to efficiently use the cogeneration system, power is generated in accordance with power demand and heat demand, and when the exhaust heat is used, the generated power is completely consumed and the exhaust heat is used. It is important to completely consume the heat energy. However, in general households, electric power demand and heat demand are generated with a certain regularity and concentrated in a specific time of day (for example, from wake-up to breakfast and before and after dinner). However, power demand and heat demand are not completely correlated, and vary depending on individual household characteristics (number of families, equipment used, number of people staying in the daytime, etc.), so both power demand and heat demand However, it was difficult to carry out efficient power generation.

  The present invention has been made in view of the above-described problems, and an object thereof is to provide a cogeneration system capable of solving the above problems and performing efficient power generation with respect to both power demand and heat demand. There is.

In order to achieve this object, a first characteristic configuration of a cogeneration system according to the present invention includes a generator unit capable of outputting AC power, and the AC power is connected to a commercial power system and a grid connection to a power load. A cogeneration system configured to be able to supply power and supply heat energy to a thermal load, with the start of a specific electrical device installed to be able to supply power from the commercial power system A control means for controlling the operation of the generator unit by receiving a specific electric device start signal transmitted in this manner, and the specific electric device is used at least as a feature of the usage form of the specific electric device an electrical equipment heat demand is increased after the start, the heat load is a generated heat load of the heat demand with the use of the particular electrical device, said control means Wherein when receiving a specific electric equipment start signal, on the basis of the occurrence of the power demand in a particular electrical device to predict the heat demand in the heat load, that controls the operation of the generator unit based on the prediction It is.

  According to the first characteristic configuration of the cogeneration system, since the control unit is provided, it is possible to measure the start timing of the cogeneration system by starting the specific electric device. It is possible to efficiently use the exhaust heat generated by the power generation performed to supply power to the heat demand that increases after the start of the use of the electrical equipment, and as a result, the heat energy can be used efficiently. In addition, it is possible to provide a cogeneration system that can generate power efficiently not only for power demand but also for heat demand.

  A second characteristic configuration of the cogeneration system is that, in addition to the first characteristic configuration, the specific electric device is an electric cooking device.

  According to the second characteristic configuration of the cogeneration system, heat demand such as hot water supply demand that increases after the use of the electric cooking equipment and the use of the electric cooking equipment is regular according to the life pattern in a general household, and Since it is performed throughout the year, it is possible to efficiently and more reliably generate power by the cogeneration system not only for power demand but also for heat demand.

  A third characteristic configuration of the cogeneration system is that, in addition to the second characteristic configuration, the specific electric device is an electromagnetic cooking device.

  According to the third characteristic configuration of the above-mentioned cogeneration system, the electromagnetic cooking device corresponds to a device that has an overwhelmingly high power demand among household electric appliances, and the power generation performed to supply power to the electromagnetic cooking device. Since the exhaust heat energy generated in the process becomes higher, it is possible to produce a higher effect of using the exhaust heat energy. Moreover, since the cogeneration system power generation can be effectively used regardless of the operation state of other electric devices, the energy use efficiency can be further increased.

  A fourth characteristic configuration of the cogeneration system is characterized in that, in addition to any one of the above characteristic configurations, the rated power consumption of the specific electrical device is equal to or higher than the rated output of the cogeneration system. is there.

  According to the fourth characteristic configuration of the cogeneration system, since the specific electric device can use all the electric power generated by the cogeneration system, the electric energy generated by the cogeneration system is wasted. As a result, an energy efficient cogeneration system can be provided.

  According to a fifth characteristic configuration of the cogeneration system, in addition to any one of the characteristic configurations described above, the control unit is configured to supply electric power to the specific electrical device from a predicted heat demand of the thermal load for one day. A power generation plan means for creating a power generation plan for covering a shortage of heat energy generated by subtracting the amount of generated heat energy, wherein the power generation plan means determines the amount of power corresponding to the shortage of heat energy as the specific electric device. In a time zone other than the time zone in which there is an operation record of the power generation, a power generation plan is created by dispersing so as not to exceed the predicted power demand by time zone of the power load before the time zone where the thermal energy shortage occurs In the point.

  According to the fifth characteristic configuration of the cogeneration system, by providing the control means with a power generation planning means, supply of heat demand can be achieved only with heat energy generated by power generation performed for the specific electrical equipment. Even if it cannot be covered, it is possible to supplement the thermal energy with the planned power generation that is distributed so that it does not exceed the predicted power demand for each time period predicted from past results. It is possible to supply power and heat energy that meet the heat demand.

  According to a sixth characteristic configuration of the cogeneration system, in addition to any one of the characteristic configurations described above, the control unit has a predetermined cumulative value of the amount of heat energy generated when power is supplied to the specific electrical device. When the heat demand is exceeded, the control is to stop the operation.

  According to the sixth characteristic configuration of the cogeneration system, the heat demand generated by the power generation performed for the specific electrical device is generated within a predetermined time after the start of use of the specific electrical device. When surplus occurs exceeding the amount, wasteful power generation can be suppressed by stopping the operation of the cogeneration system, and high energy efficiency can be maintained.

  According to a seventh feature configuration of the cogeneration system, in addition to any one of the feature configurations described above, the control unit may be configured such that a cumulative value of the amount of heat energy generated when power is supplied to the specific electrical device is a predetermined value. When the heat demand is exceeded, a starting control signal is transmitted to a specific heat load.

  According to the seventh characteristic configuration of the cogeneration system, the heat energy generated by the power generation performed for the specific electric device is generated in a predetermined time after the start of use of the specific electric device. When surplus is generated exceeding the amount, it is possible to efficiently use surplus heat energy by receiving a start control signal transmitted by the control means and starting a specific heat load, so that high energy efficiency Can be maintained.

  In addition, the characteristic configuration of the electric cooking appliance according to the present invention for achieving the above object is that the electric power can be supplied to the electric power load in a grid connection with the commercial electric power system, and the thermal energy is supplied to the thermal load. The point is that a start signal for urging the cogeneration system to start is transmitted to the cogeneration system configured to be able to supply.

  According to the characteristic configuration of the electric cooking device, since the start signal that prompts the cogeneration system to start is transmitted when the electric cooking device is started, the cogeneration system can start operation in synchronization with the start of the electric cooking device. As a result, it becomes possible to efficiently use the exhaust heat generated by the power generation performed to supply electric power to the electric cooking appliance for heat demand such as hot water supply that increases after the electric cooking appliance starts. Efficient use of the power and heat energy generated by the system is possible, and the cogeneration system can be operated to generate power efficiently not only for power demand but also for heat demand.

  Embodiments of a cogeneration system according to the present invention (hereinafter referred to as “the present invention system” as appropriate) and an electric cooking appliance (hereinafter referred to as “the present invention apparatus” as appropriate) will be described with reference to the drawings.

<First Embodiment>
As shown in FIG. 1, the system 10 of the present invention is a household gas cogeneration system that uses city gas as a fuel source and generates electric power and heat energy at the same time, and outputs mechanical rotational energy by combustion of city gas. A generator unit 3 composed of a gas engine 1 and a generator 2 that converts the rotational energy into electrical energy and outputs AC power, and the first AC power generated by the generator 2 has the same voltage and frequency as the commercial power system 20. The system AC inverter 4 for converting the converted second AC power into the commercial power system 20 and the heat for recovering the exhaust heat generated from the gas engine 1 Operation of the heat exchanger / heater unit 6 using the exhaust heat and the generator unit 3 for using the heat energy recovered by the heat exchanger 5 for hot water supply / heating. Configured with a control unit 7 for controlling.

  During power generation by the system 10 of the present invention, the power generated by the system 10 of the present invention (hereinafter simply referred to as “generated power”) is commercial power supplied from the commercial power system 20 (for example, single-phase three-wire AC 100V / 200V). (50 Hz or 60 Hz)) and the power is supplied to the power load 21 in the home. Here, the electric power load 21 includes home appliances such as refrigerators and televisions and lighting fixtures used in general homes, and electromagnetic cooking equipment 22 (generally called “IH cooking heater”) which is a kind of electric cooking equipment. ) Is included.

  The waste heat utilization hot water supply / heating unit 6 is provided with a hot water storage tank (not shown) for temporarily storing the thermal energy recovered by the heat exchanger 5 in a hot water state, thereby generating hot water supply demand (an example of heat demand). The hot water can be supplied from the hot water storage tank. Further, the exhaust heat utilization hot water supply / heating unit 6 is also provided with a heat exchanger for heating (not shown) and a heat exchanger for bathing (not shown). The heat energy recovered by the heat exchanger 5 can be used. Accordingly, the heat load 23 connected to the exhaust heat utilization hot water supply / heating unit 6 includes various hot water outlets, hot water heaters, bathtubs, and the like.

  Here, for example, 1 kW is assumed as the power generation output of the system 10 of the present invention, and about 3 to 4 kW is assumed as the exhaust heat output. On the other hand, the electric power demand in the state which does not use the electromagnetic cooking appliance 22 in a general home is about 300 W at the minimum and about 1.5 to 2 kW at the maximum throughout the day as illustrated in FIG. . In addition, since the daily heat demand in a general household is lower than the daily power demand, if the system 10 of the present invention with a power generation output of 1 kW is always operated, the output thermal energy is wasted, so the power demand It is necessary to operate with good timing in a time zone with high heat demand.

  The control means 7 is a control means for controlling the start, stop, and output of the operation of the generator unit 3, and is configured using a microcomputer or the like, according to the control procedure of the operation control program stored in the built-in memory. Operation control of the generator unit 3 is executed based on a control signal and a status signal input from the outside.

In the present embodiment, an IH start signal (an example of a specific electric device start signal) _SIH that is output during operation of the electromagnetic cooking device 22 is used as one of the control signals input to the control means 7. The IH start signal S _IH is provided when the electromagnetic cooking device 22 starts by providing a dedicated current detector 25 such as a current transformer on the power line 24 branched from the domestic distribution board and connected only to the electromagnetic cooking device 22. Since the alternating current is supplied to the power line 24, the current detector 25 can detect the current supply state and output the IH start signal _SIH . As a result, the control means 7 can detect the operation start and operation state of the electromagnetic cooking device 22 by inputting the IH start signal S _IH. 3 is started.

  The electromagnetic cooking device 22 normally has a rated power consumption of 3 to 4.8 kW, which is larger than the highest power demand of ordinary households, and is larger than the rated output of the generated power of the system 10 of the present invention. For this reason, all the generated electric power of the system 10 of the present invention is effectively used by the electromagnetic cooking device 22. Furthermore, since the use of the electromagnetic cooking device 22 is usually for cooking purposes, the demand for hot water supply is expected to increase during or after cooking, so the thermal energy output in the operation of the system 10 of the present invention is hot water. It is used effectively in the state. More specifically, since the average use time of the electromagnetic cooking device 22 during dinner cooking is about 1 hour, the system 10 of the present invention outputs thermal energy of about 4 kW (= 3440 kcal). Since water temperature changes between 10-30 degreeC, when using 40 degreeC warm water, it becomes the calculation which can use 115-334 liters of warm water with the said thermal energy output. Since the amount of water consumed in the dishwashing after dinner is about 100 liters, the heat energy consumed in the dishwashing and the like is generated along with the power supply to the electromagnetic cooking device 22 during dinner cooking, so the time delay from generation to consumption Therefore, there is almost no heat loss due to the delay, and the generated power and heat energy can be used very efficiently. That is, the user of the present invention system 10 in the home can make effective use of energy without being conscious of efficiently using electric power and thermal energy in a timely manner.

In addition, when dishwashing after dinner is performed in a dishwasher, the amount of hot water consumed is about 13 liters, but since the temperature of the hot water is higher than 40 ° C., a certain amount of heat demand is generated. It may happen that the heat energy generated together with the power supply to the electromagnetic cooking device 22 is not consumed effectively after dinner cooking. In such a case, even if the IH start signal S _IH is input, it is more likely that energy efficiency is better when the operation of the system 10 of the present invention is stopped. Therefore, the control means 7, based on the control state of the generator unit 3, an accumulated value of the thermal energy output from the input of IH start signal S _IH calculated, generated at dinner cooking in the home preset Is controlled so as to stop the operation of the generator unit 3 at the time when the estimated heat demand exceeds. Or when the hot water supply to the bathtub is scheduled after dinner of the day, the control means 7 inputs the said hot water supply demand into the control means 7, and the control means 7 makes the said accumulated value the said estimated heat demand amount. When exceeding, it is preferable to output a start control signal for automatically starting hot water supply to the bathtub to a controller that automatically controls hot water supply to the bathtub.

Second Embodiment
Next, a second embodiment of the system 10 of the present invention will be described. In the first embodiment, the case where the activation of the system 10 of the present invention is performed in synchronization with the start of the electromagnetic cooking device 22 has been described. However, the heat energy consumed in the home is related to the operation of the electromagnetic cooking device 22. In addition to the demand for hot water supply (for example, washing dishes), there are other demands for hot water supply (for example, hot water for bathtubs, showers at the time of bathing, washing surfaces, etc.) or heating demand (for hot water floor heating, etc.). If only the present invention system 10 is operated only when the cooking appliance 22 is operated, there are cases where it is not possible to cover all the heat demand throughout the day. Therefore, in the second embodiment, the function of the power generation planning unit 8 is added to the control unit 7 of the system 10 of the present invention, and the following processing can be executed.

  Similarly to the other functions of the control means 7, the power generation plan means 8 also follows the control procedure of the power generation plan creation program stored in the built-in memory, based on the control signals and data input from the outside, and Create a power generation plan for operation control.

  As shown in FIG. 3, the power generation planning means 8 includes a heat demand prediction means 11 that is provided in the control means 7 and creates a predicted heat demand for each day of the heat load 23, and a power load 21. The heat generated by the power supply to the electromagnetic cooking appliance 22 from the daily predicted heat demand of the heat load 23 in cooperation with the power demand prediction means 12 for creating the predicted power demand for each time zone of (22). Create a power generation plan to cover the shortage of thermal energy minus energy.

Specifically, the heat demand prediction means 11 receives the measurement data of the hot water supply amount and the hot water supply temperature supplied from the exhaust heat utilization hot water supply and heating unit 6 to the thermal load 23, and calculates the heat energy consumed for each time zone. Then, it is stored in a predetermined storage device as actual heat energy consumption data. Then, for example, based on the actual data of the same day one day ago, two days ago, and one week ago, the heat demand for each time zone is predicted (see FIG. 4A). In addition, the power demand prediction means 12 detects the current provided in the power line 26 before (upstream) branching to the electromagnetic cooking device 22 in order to measure the load power of all the power loads 21 including the electromagnetic cooking device 22. Receiving measurement data from a voltmeter (not shown) provided in the converter 27 and the grid interconnection inverter 4, calculating power consumption for each time zone, and storing a predetermined storage device as actual power consumption data Save to. Then, for example, based on the actual data of the same day one day ago, two days ago, and one week ago, the power demand for each time zone is predicted (see the curve portion in FIG. 4B). In addition, the electric power demand prediction means 12 acquires separately the electric power generation performance data during the driving | operation period of the electromagnetic cooking appliance 22 (refer the black coating part of FIG. 4 (B)). The power generation result data can be derived from the control information of the control means 7 and the IH start signal _SIH .

  First, the power generation plan means 8 starts from the actual power consumption data of the electromagnetic cooking device 22 and generates heat energy generated by the system 10 during the operation period of the electromagnetic cooking device 22 for one day (the black portion of FIG. 4C). ) And the thermal energy generated during the operation period of the electromagnetic cooking appliance 22 from the total daily heat demand of the predicted heat demand (broken line portion in FIG. 4C) created by the heat demand prediction means 11 Subtract and calculate the thermal energy shortage. If the thermal energy shortage is a positive value, it is determined that there is a shortage of thermal energy, and the required amount of power corresponding to the thermal energy shortage is calculated. Next, the required electric energy is set according to the time zone created by the power demand prediction means 12 before the time zone in which the thermal energy shortage occurs in a time zone other than the time zone in which the electromagnetic cooking device 22 has been operated. A power generation plan (blacked portion in FIG. 4D) is created by distributing the power load so as not to exceed it. In addition, the broken line part of FIG.4 (D) shows the electric power generated during the driving | operation of the electromagnetic cooking appliance 22. FIG.

<Third Embodiment>
Next, a third embodiment of the system 10 of the present invention will be described. The difference from the first embodiment is that, as shown in FIG. 5, the IH start signal S _IH input to the control means 7 uses a start signal transmitted from the electromagnetic cooking appliance 28 instead of from the current detector 25. It is a point. That is, in 3rd Embodiment, the electromagnetic cooking appliance 28 which transmits the starting signal which encourages starting of this invention system 10 at the time of starting is used. With this configuration, the operation control of the system 10 of the present invention can be performed just like the configuration of the first embodiment.

  Hereinafter, another embodiment will be described.

  <1> In the above embodiment, an electromagnetic cooking device is used as an example of an electric device whose heat demand increases after the start of use. However, the electric device may be an electric cooking device other than the electromagnetic cooking device, or other similar heat. It may be an electric device with an increase in demand.

  <2> In the above embodiment, the system 10 of the present invention has been described by taking a gas engine cogeneration system in which the generator unit 3 is composed of the gas engine 1 and the generator 2 as an example, but the generator unit 3 uses city gas as fuel. It may be a fuel cell as a source. In the case of the fuel cell cogeneration system, since the generator unit 3 outputs DC power, the grid-connected inverter 4 to be used also uses a type that converts DC power into AC power. In the case of the fuel cell cogeneration system, since the ratio of the generated power to the output thermal energy is approximately 1: 1, the operation stop control of the system 10 according to the present invention or the second Although it is necessary to partially change the power generation plan creation in the embodiment, the basic idea is the same.

  Further, the system 10 of the present invention may be a cogeneration system other than the gas engine cogeneration system and the fuel cell cogeneration system. Furthermore, the system 10 of the present invention is not limited to a cogeneration system using city gas as a fuel source.

The block block diagram which shows one Embodiment of the cogeneration system which concerns on this invention Explanatory diagram showing the fluctuation pattern of daily power demand in the home The block block diagram which shows one structural example of the control means for the power generation plan preparation of the cogeneration system which concerns on this invention The figure explaining the power generation plan preparation procedure of the cogeneration system which concerns on this invention The block block diagram which shows other embodiment of the cogeneration system which concerns on this invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1: Gas engine 2: Generator 3: Generator unit 4: Grid connection inverter 5: Heat exchanger 6: Waste water use hot water supply heating unit 7: Control means 8: Power generation plan means 9: Computer 10: According to the present invention Cogeneration system 11: Heat demand prediction means 12: Electric power demand prediction means 20: Commercial power system 21: Electric power load 22: Electromagnetic cooking equipment 23: Thermal load 24: Electric power line 25: Current detector 26: Electric power line 27: Current detector 28 : Electromagnetic cooking device (electric cooking device) according to the present invention
S _IH : IH start signal (specific electric equipment start signal)

Claims (8)

An output capable generator unit AC power, the AC power of commercial power system and by the system interconnection possible supply power to the power load, and the heat energy is configured to be supplied to the heat load Cogeneration system,
Comprising a control means for receiving a specific electrical device start signal transmitted with the start of a specific electrical device installed so as to be able to supply power from the commercial power system, and controlling the operation of the generator unit ;
The specific electric device is an electric device whose heat demand increases at least after the start of use as a feature of the use form of the specific electric device ,
The heat load is a heat load that generates a heat demand with the use of the specific electrical device,
When the control means receives the specific electrical equipment start signal, the control means predicts the heat demand in the thermal load based on the generation of power demand in the specific electrical equipment, and based on the prediction, the generator unit A cogeneration system that controls operation .   The cogeneration system according to claim 1, wherein the specific electric device is an electric cooking device.   The cogeneration system according to claim 2, wherein the specific electric device is an electromagnetic cooking device.   The cogeneration system according to any one of claims 1 to 3, wherein a rated power consumption of the specific electrical device is equal to or higher than a rated output of the cogeneration system. The control means generates a power generation plan for covering a shortage of thermal energy generated by subtracting the amount of thermal energy generated with the power supply to the specific electrical equipment from the daily predicted heat demand of the thermal load. With planning means,
The power generation planning means, the amount of electric power corresponding to the shortage of thermal energy, in a time zone other than the time zone in which the specific electric equipment has been operated before the time zone in which the thermal energy shortage occurs, The cogeneration system according to any one of claims 1 to 4, wherein the power generation plan is created by distributing the power load so as not to exceed the predicted power demand by time of the power load.   The said control means performs control which stops a driving | operation, when the cumulative value of the amount of thermal energy generated with the power supply with respect to the said specific electric equipment exceeds predetermined heat demand. The cogeneration system according to any one of 1 to 5.   The control means transmits a start control signal to a specific heat load when a cumulative value of the amount of heat energy generated with power supply to the specific electric device exceeds a predetermined heat demand amount. The cogeneration system according to any one of claims 1 to 5, wherein: The cogeneration system according to any one of claims 1 to 7, wherein the cogeneration system is configured to be capable of supplying power in a grid-connected manner with a commercial power system and to supply heat energy to the heat load. An electric cooking device that transmits a start signal that prompts the system to start the cogeneration system when the system is started.

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