JP5381084B2 - Cogeneration system and hot water storage system - Google Patents

Description

  The present invention relates to a cogeneration system and a hot water storage system.

  As an example of the cogeneration system, as shown in FIG. 1 of Patent Document 1, a power generation device (a combined heat and power supply device 2 having a fuel cell 6) that supplies power to a load device (electric power load 16), and power generation An operation control device (control means 70) for controlling the power generation device so as to obtain a power generation amount according to the quantity instruction value, a hot water storage tank (hot water storage tank 22) for storing hot water recovered from the exhaust heat of the power generation device, and a hot water storage tank There is known an auxiliary heating device (boiler means 42) that introduces hot water in a hot water tank and heats it out when the amount of hot water in the inside becomes a predetermined amount or less.

  In this cogeneration system, when the predicted hot water storage amount of the hot water storage tank 22 is equal to or less than the set minimum heat storage amount, hot water at a predetermined temperature (for example, 80 ° C.) in the hot water storage tank 22 is consumed and hot water remains. In such a case, the boiler means 42 is operated to generate hot water, the hot water generated by the boiler means 42 is supplied through the hot water discharge channel 40, and fuel is consumed by the boiler means 42. Thus, the increase correction mode is set so as to suppress such useless operation of the boiler means 42, and the temporary correction pattern increase correction is performed (step S11).

In the increase correction of the temporary operation pattern, as shown in FIG. 8 of Patent Document 1, a heat shortage time zone is selected (S11-1), and the heat shortage amount in the heat shortage time zone is the predicted hot water storage heat amount increase. It is calculated as a target value (S11-2), and a predicted energy reduction ratio is calculated for each time zone in the time zone range before the heat shortage time zone (step S11-3). The calculation of the predicted energy reduction ratio is calculated for a power generation output range larger than the power generation output of the temporary operation pattern set using the predicted hot water storage amount. Next, in relation to the calculation of the predicted energy reduction ratio, the predicted increase in hot water storage is calculated (step S11-4). In this calculation, for a power generation output range that is larger than the power generation output of the set temporary operation pattern, an increased heat amount that is larger than the predicted heat output generated by the power generation output of the temporary operation pattern, that is, a predicted increased hot water storage heat amount is calculated. . Next, the predicted energy reduction ratio is picked up (step S11-5). Since this pickup is an increase correction to prevent heat shortage, the time zone range before the heat shortage time zone, that is, the time zone range in which the predicted energy reduction ratio and the predicted increased hot water storage amount are calculated. Thus, the power generation output range is larger than the power generation output of the temporary operation pattern. When picked up in this way, the power generation output of the fuel cell 6 increases (from 300 W to 600 W), and accordingly, the predicted heat output also increases. Therefore, the predicted hot water storage heat storage amount calculation means 80 uses the hot water storage tank as the output increases. The predicted hot water storage amount 22 is calculated (step S11-6). Next, the predicted increased hot water storage heat amount integration means 118 integrates the predicted increased hot water storage heat amount (step S11-8), and it is determined whether this integrated value has reached the predicted hot water storage heat amount increase target value (step S11-9). In this way, the temporary operation pattern is increased and corrected so as to increase the power generation output.
JP 2006-97677 A

  By the way, in the cogeneration system described in Patent Document 1, in order to suppress the wasteful operation of the boiler means 42 which is an auxiliary heating device, the temporary operation pattern is increased and corrected so as to increase the power generation output. Driving is based on driving patterns. In this case, although the wasteful operation of the boiler means 42 can be suppressed and energy saving can be achieved in the entire system, the fuel cell 6 that is a power generation device can generate a relatively high power output (for example, a power output near the maximum power output of the fuel cell 6). ) Has a problem that the load on the fuel cell 6 is increased.

  The present invention has been made to solve the above-described problems, and aims to reduce the burden on the power generation device while suppressing unnecessary operation of the auxiliary heating device in the cogeneration having the auxiliary heating device. .

In order to solve the above-mentioned problems, the structural features of the invention according to claim 1 include a power generator that supplies power to the load device, hot water that collects exhaust heat from the power generator, A hot water storage tank for supplying hot water, an operation control device for controlling the power generation device according to the operation plan and controlling the power generation device so that the power generation amount corresponds to the power generation amount instruction value, and the amount of remaining hot water in the hot water storage tank is below a predetermined amount An auxiliary heating device that introduces and heats hot water from the hot water storage tank and derives it, and the operation control device includes an actual remaining hot water amount deriving means for deriving an actual remaining hot water amount in the hot water storage tank, and an actual remaining hot water amount. Offset residual hot water amount deriving means for deriving the offset residual hot water amount in the hot water tank obtained by subtracting the offset amount from the actual remaining hot water amount in the hot water tank derived by the deriving means, and consumption of the electric energy consumed by the load device Pattern, hot water Based on the consumption pattern of the amount of hot water consumed by the equipment and the amount of remaining hot water derived by the offset remaining water amount deriving means, the power generation stop time zone when the power generation of the power generation device is stopped and the power consumption of the load device An operation plan deriving unit for deriving an operation plan including a power generation operation time zone in which the continuous power generation operation of the following power generation device is performed, and the offset amount is larger than a predetermined amount which is a heating start threshold of the auxiliary heating device Is to be set to a value .

The feature in construction of the invention according to claim 2, Oite to claim 1, the offset amount is to learn from usage per use of the actual hot water quantity of the data used in the hot water used device It is set by.

Further, the structural feature of the invention according to claim 3 is that the offset amount obtained when the offset amount is increased from 0 and the heating operation of the auxiliary heating device according to claim 1 or claim 2 is consumed. The offset amount when the energy amount consumed for the heating operation of the auxiliary heating device becomes constant from the decrease in relation to the amount of energy to be used is set to the offset amount used in the offset remaining hot water amount deriving means It is.

Further, the structural features of the invention according to claim 4 are a hot water generator for generating hot water, a hot water storage tank for storing hot water and supplying the hot water to a hot water use device, and a hot water storage tank for controlling the hot water generator. And an auxiliary heating device that introduces and heats the hot water in the hot water storage tank when the remaining hot water amount in the hot water storage tank reaches a predetermined amount or less . The actual remaining hot water amount deriving means for deriving the actual remaining hot water amount, and the offset remaining hot water amount in the hot water tank obtained by subtracting the offset amount from the actual remaining hot water amount in the hot water tank derived by the actual remaining hot water amount deriving means Based on the offset residual hot water amount deriving means, the consumption pattern of the hot water consumed by the hot water using device, and the offset residual hot water amount derived by the offset residual hot water amount deriving means. Comprising a planning deriving means, the offset amount is to be set to a predetermined amount greater than a heating start threshold of the auxiliary heating device.

  In the invention according to claim 1 configured as described above, the actual remaining hot water amount deriving unit derives the actual remaining hot water amount in the hot water storage tank, and the offset remaining hot water amount deriving unit is derived by the actual remaining hot water amount deriving unit. Deriving the offset remaining hot water amount in the hot water tank obtained by subtracting the offset amount from the actual remaining hot water amount in the hot water tank, and the operation plan deriving means is the consumption pattern of the electric energy consumed by the load device, the hot water usage device Based on the consumption pattern of the amount of hot water consumed and the offset remaining hot water amount derived by the offset remaining hot water amount deriving means, the power generation stop time zone when power generation of the power generation device is stopped, and power generation that follows the power consumption of the load device An operation plan including a power generation operation time zone in which continuous power generation operation of the apparatus is performed is derived. Then, the operation control device controls the power generation device according to the operation plan and controls the power generation device so that the power generation amount corresponds to the power generation amount instruction value.

As a result, by carrying out the operation plan derived using the offset remaining hot water amount obtained by subtracting the offset amount from the actual remaining hot water amount in the hot water tank, the remaining hot water amount in the hot water tank is at least offset. Become. That is, at least an offset amount can be secured for the amount of hot water remaining in the hot water tank. Therefore, if the offset amount is set to a value larger than the heating start threshold value of the auxiliary heating device, the heating operation of the auxiliary heating device can be suppressed as much as possible even when the hot water in the hot water tank is used up. Furthermore, the amount of remaining hot water can be increased by increasing the power generation operation time zone by the time corresponding to the offset amount without increasing the output power of the power generation device as in the prior art. Therefore, it is possible to reduce the burden on the power generation device by suppressing the operation of the power generation device with a relatively high power generation output. Thus, according to the cogeneration which concerns on this invention, the burden of an electric power generating apparatus can be reduced, suppressing the useless operation of an auxiliary heating apparatus.
In addition to this, when the amount of remaining hot water in the hot water storage tank becomes a predetermined amount or less, it further includes an auxiliary heating device that introduces and heats hot water from the hot water storage tank, and the offset amount is a heating start threshold value of the auxiliary heating device. It is set to a value larger than a certain predetermined amount. This ensures that the amount of hot water remaining in the hot water tank is greater than the heating start threshold of the auxiliary heating device, and suppresses the heating operation of the auxiliary heating device as much as possible even when the hot water in the hot water tank is exhausted. can do.

In the invention according to Claim 2 as constructed above, Oite to claim 1, the offset amount is learned from usage per use of the actual hot water quantity of the data used in the hot water used device Is set by As a result, even in the case of sudden use that is less than the offset amount and does not appear regularly in the consumption pattern of hot water (for example, using hot water to gargle), such usage is reduced. Can be covered with an offset amount. In this case, since the offset amount can be set according to the amount of use once, energy saving can be improved even when a sudden small amount of hot water is used.

In the invention according to claim 3 configured as described above, for the heating operation of the offset amount and the auxiliary heating device obtained when the offset amount is increased from 0 in claim 1 or claim 2 . In relation to the consumed energy amount, the offset amount when the energy amount consumed for the heating operation of the auxiliary heating device becomes constant from the decrease is set to the offset amount used in the offset remaining hot water amount deriving means. . This makes it possible to use the offset amount with the highest energy saving amount for each of the energy consumed by the auxiliary heating device and the energy for generating hot water for the offset amount. Can be maintained.

In the invention according to claim 4 configured as described above, the actual remaining hot water amount deriving unit derives the actual remaining hot water amount in the hot water storage tank, and the offset remaining hot water amount deriving unit is derived by the actual remaining hot water amount deriving unit. The amount of residual hot water in the hot water tank obtained by subtracting the amount of offset from the actual amount of hot water in the hot water tank is derived, and the operation plan deriving means determines the consumption pattern of the amount of hot water consumed by the hot water usage device and the remaining offset. An operation plan for the hot water generator is derived based on the offset remaining hot water amount derived by the hot water amount deriving means. Then, the operation control device controls the hot water generation device and the hot water storage tank according to the operation plan.

As a result, by carrying out the operation plan derived using the offset remaining hot water amount obtained by subtracting the offset amount from the actual remaining hot water amount in the hot water tank, the remaining hot water amount in the hot water tank is at least offset. Become. That is, at least an offset amount can be secured for the amount of hot water remaining in the hot water tank. Therefore, if the offset amount is set to a value larger than the heating start threshold value of the auxiliary heating device, the heating operation of the auxiliary heating device can be suppressed as much as possible even when the hot water in the hot water tank is used up. As a result, the offset amount can be set appropriately, and the auxiliary heating device itself need not be provided, so that the price of the system can be reduced.
In addition to this, when the amount of remaining hot water in the hot water storage tank becomes a predetermined amount or less, it further includes an auxiliary heating device that introduces and heats hot water from the hot water storage tank, and the offset amount is a heating start threshold value of the auxiliary heating device. It is set to a value larger than a certain predetermined amount. This ensures that the amount of hot water remaining in the hot water tank is greater than the heating start threshold of the auxiliary heating device, and suppresses the heating operation of the auxiliary heating device as much as possible even when the hot water in the hot water tank is exhausted. can do.

  Hereinafter, an embodiment of a cogeneration system according to the present invention will be described. FIG. 1 is a schematic diagram showing an overview of this cogeneration system. The cogeneration system includes a power generator 10 that supplies power to the load device 21, a hot water tank 30 that stores hot water from which the exhaust heat of the power generator 10 has been collected, and hot water from the hot water tank 30 that is introduced and heated to be derived. And an operation control device 50 that controls the power generation device 10 so as to obtain a power generation amount corresponding to the power generation amount instruction value.

  The power generation device 10 is a fuel cell power generation device, and includes a power generator 11 that generates DC power, and a converter (for example, an inverter) 12 that converts the DC power supplied from the power generator 11 into AC power and outputs the AC power. ing. In addition to the fuel cell power generation device, the power generation device 10 may be configured by a prime mover such as a diesel engine, a gas engine, a gas turbine, or a micro gas turbine, and a generator driven by the prime mover.

  The generator 11 includes a reformer, a carbon monoxide reduction device (hereinafter referred to as a CO reduction device), and a fuel cell. In the reformer, the fuel supplied from the fuel supply device 13 is steam-reformed with water supplied from the water supply device 14 to generate a hydrogen-rich reformed gas, which is led to the CO reduction device. The CO reduction device reduces carbon monoxide contained in the reformed gas and leads it to the fuel cell. The fuel cell generates power using hydrogen in the reformed gas supplied to the fuel electrode and air that is an oxidant gas supplied to the air electrode.

  Between the fuel supply device 13 and the power generator 11, a flow meter 13a serving as a fuel input amount detecting means for detecting the amount of fuel input to the power generator 11 is provided. The flow meter 13a detects the detected fuel input amount. Is transmitted to the operation control device 50. Note that the amount of fuel input in the case of a fuel cell power generator refers to the amount of fuel supplied to the reformer.

  The converter 12 is connected to a plurality of load devices 21 installed at the power use place 20 via the power transmission line 15, and the AC power output from the converter 12 is supplied to each load device 21 as necessary. Has been supplied to. The converter 12 is provided with a wattmeter 10a which is a power generation output amount detecting means for detecting a power generation output amount output from the power generation device 10, and the wattmeter 10a sends the detected power generation output amount to the operation control device 50. It is supposed to send.

  The load device 21 is an electric appliance such as an electric lamp, iron, television, washing machine, electric kotatsu, electric carpet, air conditioner, and refrigerator. In addition, the power source 15 of the power company is also connected to the power transmission line 15 that connects the converter 12 and the power use place 20 (system connection), and the total power consumption of the load device 21 is determined by the power generation amount of the power generation device 10. When the amount exceeds, the insufficient power is received from the system power supply 16 and compensated. The wattmeter 22 is power consumption detection means for detecting the power consumption consumed by the load device 21, detects the total power consumption of all the load devices 21 used in the power usage place 20, It is transmitted to the operation control device 50.

  The generator 11 is connected to a cooling circuit 31 through which a heat medium for recovering exhaust heat of the generator 11 and cooling the generator 11 circulates. On the cooling circuit 31, the generator 11, the heat exchanger 32, the radiator 37, and the pump 31a are arrange | positioned. The radiator 37 is a cooling unit that cools the heat medium circulating in the cooling circuit 31, and is controlled to be turned on / off by a command from the operation control device 50. The heat medium is cooled when in the on state, and is cooled when in the off state. It is something that does not. The pump 31a circulates the heat medium of the cooling circuit 31 in the direction of the arrow in the figure, and is controlled by the operation control device 50 to control the discharge amount (delivery amount).

  On the other hand, a hot water circulation circuit 33 for heating hot water (hot water) in the hot water tank 30 is connected to the hot water tank 30 described later. One end of the hot water circulation circuit 33 is connected to the lower part of the hot water tank 30, and the other end is connected to the upper part of the hot water tank 30. On the hot water circulation circuit 33, the hot water tank 30, the pump 33a, and the heat exchanger 32 are arranged in this order starting from the hot water tank 30. The pump 33a sucks hot water in the lower part of the hot water tank 30, passes the hot water circulation circuit 33 in the direction of the arrow in the figure, and sends it out to the upper part of the hot water tank 30. The pump 33a is controlled by the operation control device 50 to discharge the amount. (Sending amount) is controlled. The heat exchanger 32 performs heat exchange between the heat medium circulating in the cooling circuit 31 and the hot water circulating in the hot water circulation circuit 33.

  Thus, during power generation by the generator 11, the pump 31 a is driven to circulate the heat medium through the cooling circuit 31, and the pump 33 a is driven to circulate hot water through the hot water circulating circuit 33. The exhaust heat of the generator 11 is recovered by a heat medium. Heat exchange between the heat medium and hot water is performed by the heat exchanger 32. In the heat exchanger 32, the exhaust heat of the generator 11 recovered in the heat medium is recovered in hot water and the hot water is heated. For example, in the case of a fuel cell power generator, the exhaust heat of the power generator 11 refers to the exhaust heat of a fuel cell stack, the exhaust heat of a reformer, or the like, and in the case of an engine power generator, the exhaust heat of the engine. However, the present invention is not limited to this, and any recoverable exhaust heat such as the heat of the generator itself can be used.

  The hot water tank 30 is provided with one columnar container, in which hot water is stored in a layered manner, that is, hot water in the upper part is the hottest and becomes lower as it goes to the lower part, and the hot water in the lower part is stored at the lowest temperature. It has become so. Hot water stored in the hot water tank 30 is derived from the upper part of the columnar container of the hot water tank 30, and water such as tap water from the water supply device 14 (low temperature water) so as to replenish the derived amount. Is introduced from the lower part of the columnar container of the hot water tank 30. Such a hot water tank 30 is installed near the power generation apparatus 10.

  Inside the hot water tank 30, a temperature sensor group 34 that is a remaining hot water amount detection sensor is provided. The temperature sensor group 34 includes a plurality (ten in the present embodiment) of temperature sensors 34-1, 34-2, 34-3,..., 34-10, and is arranged in the vertical direction (vertical direction). It is arranged at equal intervals (distance of 1/9 of the vertical height in the hot water tank 30). The temperature sensor 34-1 is disposed on the inner upper surface of the hot water tank 30. Each of the temperature sensors 34-1, 34-2, 34-3,..., 34-10 detects the temperature of the liquid (hot water or water) in the hot water storage tank 30 at that position. The amount of remaining hot water in the hot water storage tank 30 is derived based on the detection result of the hot water temperature at each position by the temperature sensor group. The remaining hot water amount represents the amount of heat stored in the hot water tank 30.

  Further, an auxiliary heating circuit 41 for heating hot water (hot water) in the hot water tank 30 is connected to the hot water tank 30. One end of the auxiliary heating circuit 41 is connected to the middle of the hot water storage tank 30 in the vertical direction (in this embodiment, the central part in the vertical direction), and the other end is connected to the upper part of the hot water storage tank 30. On the auxiliary heating circuit 41, the hot water tank 30, the pump 41a, and the auxiliary heating device 40 are arranged in this order starting from the hot water tank 30. The pump 41 a sucks hot water (in many cases, low-temperature hot water) in the center in the vertical direction of the hot water tank 30, passes the auxiliary heating circuit 41 in the direction of the arrow in the figure, and sends it to the upper part of the hot water tank 30. The discharge amount (delivery amount) is controlled by the operation control device 50.

  The auxiliary heating device 40 introduces hot water from the hot water storage tank 30 and heats it out when the remaining hot water amount in the hot water storage tank 30 becomes a predetermined amount or less. In the present embodiment, a gas burner is used as the auxiliary heating device 40, but an electric heating device may be used. The auxiliary heating device 40 is operation-controlled according to a command from the operation control device 50. That is, the operation control device 50 detects the amount of remaining hot water in the hot water storage tank 30, and if the detected value is larger than a predetermined amount, the operation of the auxiliary heating device 40 is not performed (fuel supply is stopped and combustion is not performed).

  On the other hand, the operation control device 50 causes the auxiliary heating device 40 to perform a combustion operation if the detected amount of remaining hot water is equal to or less than a predetermined amount (starts supply of fuel, ignites and burns it). The fuel may be fuel from the fuel supply device 13.

  Specifically, when the remaining hot water amount becomes equal to or less than a predetermined amount, the operation control device 50 causes the auxiliary heating device 40 to perform a combustion operation. That is, when the remaining hot water amount becomes equal to or less than the predetermined amount, the combustion operation of the auxiliary heating device 40 is started and the pump 41a is driven. Thereby, hot water (low-temperature hot water) in the central portion in the vertical direction of the hot water tank 30 is heated when passing through the auxiliary heating device 40, and then returned to the upper part of the hot water tank 30. Thereafter, when the remaining hot water amount reaches a predetermined amount, the operation control device 50 stops the combustion operation of the auxiliary heating device 40 (also stops the pump 41a).

  The auxiliary heating device 40 is not controlled by the operation control device 40, and the device itself has an independent temperature sensor (a sensor capable of detecting the amount of remaining hot water in the hot water tank 30) based on the detected value. You may make it comprise the thing in which the autonomous control which controls a combustion driving | operation is possible.

  Between the hot water storage tank 30 and the water supply device 14, a temperature sensor 38 that detects the temperature of water (for example, tap water) supplied to the hot water storage tank 30 is provided. The detection result (tap water temperature) of the temperature sensor 38 is transmitted to the operation control device 50.

  A hot water supply pipe 35 is connected to the hot water tank 30. The hot water supply pipe 35 is provided with a temperature sensor (not shown) and a flow rate sensor 36 in order from the upstream. The temperature sensor detects the temperature of the hot water after flowing out of the hot water tank 30, and the detection signal is transmitted to the operation control device 50. Although not shown, tap water from the water supply device 14 joins the hot water supply pipe 35 between the outlet of the hot water tank 30 and the temperature sensor. Thereby, when the temperature of the hot water detected by the temperature sensor is equal to or higher than the set hot water temperature, the tap water is supplied so as to be the hot water temperature and the hot water from the hot water tank 30 is lowered. The flow rate sensor 36 detects the amount of hot water consumption (hot water supply amount) supplied from the hot water storage tank 30. A detection signal of the flow sensor 36 is transmitted to the operation control device 50.

  Connected to the hot water supply pipe 35 are a plurality of hot water use devices 26a installed in a hot water use place 25 that uses hot water stored in the hot water tank 30 as hot water supply. Examples of the hot water use device 26a include a bathtub, a shower, a kitchen (kitchen faucet), and a washroom (toilet faucet). The hot water supply pipe 35 is connected to a heat utilization device 26b installed in a hot water use place 25 that uses hot water in the hot water tank 30 as a heat source. Examples of the heat utilization device 26b include bathroom heating, floor heating, and a hot water reheating mechanism. The heat utilization device 26b may use the hot water in the hot water tank 30 directly or indirectly use the hot water in the hot water tank 30. The hot water use device 26a and the heat use device 26b are hot water use devices.

  The operation control device 50 has a microcomputer (not shown), and the microcomputer includes an input / output interface, a CPU, a RAM, and a ROM (all not shown) connected via a bus. The CPU executes a program corresponding to the flowcharts of FIGS. 2 to 7, derives and updates the operation plan of the power generation apparatus, operates in accordance with the updated and stored operation plan, and generates power according to the power generation amount instruction value. The power generation device is controlled so that the amount becomes constant. The RAM temporarily stores variables necessary for executing the program, and the ROM stores the program.

  Next, the operation of the above-described cogeneration system will be described with reference to FIGS. When the main power supply (not shown) is turned on, the operation control device 50 starts the program in step 100 and advances the program to step 102. The operation control device 50 derives and updates the operation plan every first predetermined time T1 in the day by the processing of steps 102 to 112 shown in FIG. Further, the operation control device 50 operates the power generation device by the processing of steps 602 to 608 shown in FIG. 7 according to the updated operation plan. That is, the operation (power generation) of the power generation apparatus 10 is stopped or continuously generated according to the operation plan.

  The first predetermined time T1 is set to a time shorter than 24 hours (one day), and is 30 minutes in the present embodiment. This first predetermined time T1 is a time sufficient for the operation control device 50 to derive an operation plan, and heat recovery by the hot water storage tank 30 is used for unscheduled use of hot water that does not follow the consumption pattern of hot water. The time is set so that it can be handled.

  The time necessary and sufficient for the operation control device 50 to derive the operation plan may be 5 minutes or more, 10 minutes or more, or 20 minutes or more, depending on the calculation capability of the operation control device 50. The time that can be used for heat recovery by the hot water storage tank 30 for unscheduled use of hot water that does not follow the consumption pattern of hot water amount is 40 minutes or less, 50 minutes or less, or 60 minutes or less, depending on unscheduled use conditions. It is preferable that Therefore, the first predetermined time T1 is determined by each combination of a time necessary and sufficient for the operation control device 50 to derive the operation plan and a time that can cope with the heat recovery by the hot water tank 30 for unscheduled use of hot water. It can be set as the preferable range.

  In step 102, the operation control device 50 executes the program according to the power consumption pattern creation routine shown in FIG. 3, and creates and updates a power consumption pattern for one day. This power consumption pattern is a prediction of a power consumption pattern from past power consumption data for a certain period (for example, one week).

  The operation control device 50 initializes a matrix Eo_temp for creating a power consumption pattern (step 202). The operation control device 50 substitutes the power consumption of each time zone for 7 days into each element of the matrix Eo_temp. An example of the result of substitution is shown in FIG. At the beginning of installation of this system, a numerical value of an average consumption model pattern created in advance based on conditions such as family composition and region is substituted. Also, after at least one week of operation, the value of the previous power consumption pattern that is created and updated from the power consumption actually measured for each power generation stoppage time period is substituted.

  In the matrix Eo_temp, as shown in FIG. 8, the column indicates how many days ago the data is, and the row indicates the time zone of the day. The element of 1 row and 1 column is the power consumption measured at 0:00 one day ago, that is, the average value of the power consumption measured from 23:30 two days ago to 0:00 one day ago, for example, FIG. Then it is 300W. The element in 2 rows and 1 column is the power consumption measured at 0:30 the day before, that is, the average value of the power consumption measured from 0:00 to 0:30 the day before, for example, 400 W in FIG. is there. The element in the first row and the second column is the power consumption measured at 0:00 two days ago, that is, the average value of the power consumption measured from 23:30 three days ago to 2:00 two days ago. Then it is 250W. Note that the data of the day before and the data for the previous day are mixed in the data of the day before. Similarly, the data of the previous day and the data of the previous day are mixed in the data of two days ago.

  The operation control device 50 measures the power consumption for each control cycle by the wattmeter 22 (step 204), and filters the measured power consumption (step 206). In step 206, the operation control device 50 performs the following equation 1 based on the measured data and the data of the past several cases (29 cases in this embodiment) each time the power consumption is measured. Filtering is being executed. The control cycle is the same as a second predetermined time T2 described later, and is 1 minute in this embodiment.

  Note that u [k] and y [k] are current data, for example, input data and output values (process values) at time k, and z is a delay operator.

  The operation control device 50 continues to determine “NO” in step 208 until 30 minutes have elapsed from the measurement start time of the power consumption, repeatedly execute the measurement of the power consumption and the filter processing, The average value is calculated by filtering the power consumption for 30 minutes.

  Then, the operation control device 50 determines “YES” in step 208 when 30 minutes have elapsed from the measurement start time of power consumption, and reads the current time (step 210). For example, it is assumed that the current time is 0:00 and the filter processing value for 30 minutes (23: 0 to 0:00) is 500 W.

  In the matrix Eo_temp, the operation control device 50 deletes the data at the same time (the time when the power consumption is measured and the filter process is completed) seven days ago, and the remaining data at the same time (the same line) one by one. Move to the right (step 212). For example, since the current time is 0:00, as shown in FIG. 9, 440 W of the element in the first row and the seventh column, which is the data at 0:00 seven days ago, is deleted. Then, 300 W of the element of 1 row and 1 column, which is 0:00 data of 1 day before, is moved to 1 row and 2 columns, and 250 W of the element of 1 row and 2 columns, which is 0:00 data of 2 days ago, is 1 row. The other elements from 1 row 3 columns to 1 row 6 columns are also moved in the same manner.

  Then, as shown in FIG. 9, the operation control device 50 adds the filter processing value (for example, 500 W) derived as described above to an empty 1-by-1 column of the matrix Eo_temp (step 214). The operation control device 50 derives and updates the power consumption predicted value, that is, the power consumption pattern, by averaging the data of each row of the matrix Eo_temp created in this way (step 216). An example of the derived power consumption prediction value is shown in FIG. The power consumption at 0:00 is 340 W, the power consumption at 0:30 is 420 W,..., And the power consumption at 23:30 is 900 W. An example of this power consumption pattern is shown in FIG.

  Next, in step 104, the operation control device 50 executes a program in accordance with the hot water / water consumption pattern creation routine shown in FIG. 4, and creates and updates a hot water consumption pattern for one day. This hot water consumption pattern is a prediction of a hot water consumption pattern from past hot water consumption data for a certain period (for example, one week).

  That is, the operation control device 50 creates a hot water consumption pattern by the processing of Steps 302 to 316, similarly to the processing of Steps 202 to 216 described above. Specifically, the operation control device 50 initializes a matrix Qout_temp for creating a hot water consumption pattern (step 302). As with the matrix Eo_temp, the matrix Qout_temp indicates how many days ago the column is data, and the row indicates the time zone of the day.

  The operation control device 50 measures the hot water consumption for each control cycle by the flow sensor 36 (step 304), and filters the measured hot water consumption (step 306). The operation control device 50 continues to determine “NO” in step 308 until 30 minutes have elapsed from the start of measurement of hot water consumption, repeatedly execute the measurement of the hot water consumption and its filter processing, The average value is calculated by filtering hot water consumption for 30 minutes.

  Then, the operation control device 50 determines “YES” in step 308 when 30 minutes have elapsed from the measurement start time of the hot water consumption, and reads the current time (step 310). In the matrix Qout_temp, the operation control device 50 deletes the data at the same time seven days ago and moves the remaining data at the same time (the same line) one by one to the right (step 312). Then, the operation control device 50 adds the filter processing value derived in step 306 to an empty 1-row 1-column of the matrix Qout_temp (step 314). The operation control device 50 derives and stores the predicted hot water consumption value, that is, the hot water consumption pattern, by averaging the data of each row of the matrix Qout_temp created in this way (step 316). An example of this hot water consumption pattern is shown in FIG.

  Next, in step 106, the operation control device 50 executes a program in accordance with the hot water tank remaining hot water amount estimation routine shown in FIG. 5, and derives and stores the actual remaining hot water amount of the hot water tank 30 at the current time (actual Remaining hot water amount deriving means). Specifically, the operation control device 50 measures the temperature of water (for example, tap water) supplied to the hot water tank 30 by the temperature sensor 38 (step 402). The operation control device 50 measures the temperature of the hot water at each position in the hot water storage tank 30 by the temperature sensors 34-1 to 34-10 (step 404). Then, the operation control device 50 substitutes the temperature of the water to be supplied and the temperature at each position in the hot water storage tank 30 into the following equation 2 to derive the remaining hot water amount in the hot water storage tank 30 (step 406).

Here, Q is the amount of heat [J] stored in the hot water tank 30, Cp is the specific heat of water (4.189 × 10 ⁻³ [J / (kg · K)]), and V is the hot water tank. The volume is 30 (150 l = 150 kg in this embodiment), Tw is the temperature of tap water, and Ti is the i-th temperature from the top in the hot water tank 30.

  Next, in step 108, the operation control device 50 derives the offset remaining hot water amount in the hot water tank 30 obtained by subtracting the offset amount from the actual remaining hot water amount in the hot water tank 30 previously derived in step 106. (Offset remaining hot water amount derivation means). When the actual remaining hot water amount is equal to or less than the offset amount, the offset remaining hot water amount is set to zero. This is to prevent the amount of residual hot water from becoming 0 or less.

  The offset amount is set to a value larger than a predetermined amount that is a heating start threshold of the auxiliary heating device 40. The heating start threshold value is a determination threshold value at which heating of the auxiliary heating device 40 is started.

  A method for determining the offset amount will be described. We took data for multiple households and various seasons, and determined the offset amount based on the collected data. The collected data includes the amount of fuel input to the auxiliary heating device 40, the amount of fuel used for operating the power generation device 10, the amount of power consumed, the amount of hot water used, and the like. Summarizing the collected data, as shown in FIG. 11, the relationship between the offset amount and the amount of energy consumed for the heating operation of the auxiliary heating device 40 (the amount of input fuel) (indicated by a thin line in FIG. 11) The relationship between the offset amount and the energy saving amount of the entire cogeneration (shown by a thick line in FIG. 11) can be obtained. At this time, for the heating operation of the auxiliary heating device 40 in the relationship between the offset amount obtained when the offset amount is increased from 0 and the energy amount consumed for the heating operation of the auxiliary heating device 40. The offset amount when the consumed energy amount (fuel amount) becomes constant from the decrease may be set to the offset amount used to derive the offset remaining hot water amount.

  As can be seen from FIG. 11, when the offset amount is increased from 0, the operation amount of the auxiliary heating device 40 decreases at the beginning, but becomes flat when the offset amount becomes a certain value (Oa) or more. In the previous stage (offset amount is less than Oa), the target heating suppression is effective when the hot water is used up. The reason for the flatness in the later stage (offset amount is greater than Oa) This is because the auxiliary heating device 40 operates as a result of the amount of hot water used greatly exceeding the amount of exhaust heat recovered.

  On the other hand, in terms of the energy saving amount, it has a mountain shape, and its peak coincides with the subscript of the amount of fuel input to the auxiliary heating device 40 (when the offset amount is Oa). The reason for the mountain shape will be described. In the previous stage, as the offset amount increased, the amount of operation of the auxiliary heating device 40 when the hot water was used was reduced, and the energy saving rate was improved. Further, the reason for the reduction in the energy saving rate at the later stage is that it is necessary to boil that much hot water against the increase in the offset amount. Further, although the degree of influence is small, there is also an influence that the amount of heat released to the atmosphere is increased due to the increase in the offset amount.

  Further, the offset amount may be set by learning from the usage amount per use in the actual hot water amount data used in the hot water usage apparatus described above. That is, the amount of offset may be changed by estimating by learning the user's variation in hot water usage. As mentioned above, in the hot water usage pattern, the user's hot water usage method (pattern) is learned from past usage history, but until the daily use of hot water (for example, using hot water to gargle) I can't follow you. In this case, in the past, the auxiliary heating device operated each time such usage, but as a result of providing an offset to the amount of remaining hot water in the hot water tank 30, such usage is covered by the offset amount (hot water is supplied from the tank). It is possible to obtain the effect of improving the energy saving rate. In addition, the usage-amount per use is the usage-amount at the time of using a hot-water-use apparatus once, for example, the usage in the case of using hot water for washing a hand is made into one use. The usage amount per use may be the number of times hot water is used until the system is started and stopped. In this case, for example, the number of times of operation of the auxiliary heating device (number of times of use) during a predetermined period (for example, two weeks) may be detected, and the amount of offset may be increased when the number of times of operation (number of times of use) is large. In this case, an upper limit of the offset amount is provided.

  The description returns to the flowchart of FIG. In step 110, the operation control device 50 executes a program in accordance with the operation plan derivation / update storage routine shown in FIG. 6, derives an operation plan for the power generation device 10, and updates and stores the operation plan. (Operation plan deriving means).

  The operation control device 50 includes the power consumption pattern created and stored in step 102 (pattern shown in FIG. 12), and the hot water consumption pattern created and stored in step 104 (pattern shown in FIG. 13). Is read (step 502), and the offset remaining hot water amount derived in step 108 is read (step 504). And the driving | operation control apparatus 50 makes an optimal driving | operation plan using the newest information read by the process of steps 506-518.

The operation control device 50 sets the power generation stop time zone by changing the stop time for stopping power generation (starting power generation stop) and the start time for starting power generation (ending power generation stop) (step 506). For example, the stop time and the start time are changed every 30 minutes within one day (0:00 to 24:00). Thereby, all combinations of the power generation stop time zone are 0: 00 to 0: 00 (not stopped), 0: 00 to 0:30, 0: 00 to 1: 00, ..., 0: 00 to 24: 00, 0:30 to 10:00, ..., 0:30 to 24:00, ..., 23: 00 to 23:30, ..., 23: 00 to 24:00, and 23:30 ˜24: 00 and 1177 ways (= ₄₉ C ₂ +1) can be set.

  The operation control device 50 derives an energy saving effect index value for each of all the combinations (steps 508 to 514). First, the operation control device 50 determines the power generation stop time zone set in step 506, the power consumption pattern read in step 502, and the following equation 3 for each set time unit (24 hours in this embodiment) of the power consumption pattern. The amount of exhaust heat recovery at the time is derived (step 508). For example, in the first calculation, the exhaust heat recovery amount for the first combination 0:00 to 0:00 is derived. Further, when an operation plan in which the power generation stoppage time period is from 4:00 to 17:00 is derived as an optimal operation plan, the predicted value of the exhaust heat recovery amount is derived as shown in FIG.

Here, Qin [k] is the exhaust heat recovery amount [J] at time k (time), Eo is the power consumption pattern [W], and td is the prediction interval (30 minutes in this embodiment). is there. a ₁ is the exhaust heat recovery characteristic [W / W], a ₂ is the exhaust heat recovery characteristic [W], and both values are calculated from experimental data obtained using an actual machine. Note that the denominator of the unit of the exhaust heat recovery characteristics a ₁ molecular indicates watt electric represents the watts of heat.

  According to the above formula 3, it is possible to derive the exhausted heat recovery amount every hour on the hour and 30 minutes. Further, if the time is not the set power generation stop time zone (if the power generation operation time zone), the amount of exhaust heat recovery can be derived using the above equation of Equation 3. If the power generation stoppage time period is set, the exhaust heat recovery amount can be derived using the equation below. That is, since no power is generated, the amount of exhaust heat recovery is zero.

  If the power consumption amount of the power consumption pattern does not exceed the maximum power generation amount of the power generator 11, the power consumption pattern Eo can be used as it is in the above equation 3, but if it exceeds, the power consumption pattern Eo in the above equation 3 is used. Is used instead of the maximum power generation amount of the generator 11.

  The operation control device 50 derives (predicts) the transition of the amount of remaining hot water in the hot water tank 30 based on the operation plan based on the power generation stop time period set in step 506 (step 510). The operation control device 50 substitutes the hot water consumption pattern Qout read in step 502, the offset remaining hot water amount read in step 504, and the exhaust heat recovery amount Qin derived in step 508 into the following equation 4, and the offset remaining in the hot water tank 30 is substituted. Deriving the transition of hot water volume. For example, in the first calculation, the transition of the amount of remaining hot water in the hot water storage tank 30 for the first combination 0:00 to 0:00 is derived. Further, when an operation plan in which the power generation stoppage time period is from 4:00 to 17:00 is derived as an optimal operation plan, a predicted value of the offset remaining hot water amount is derived as shown by a thin line in FIG.

  Here, Q [k] is a transition predicted value of the amount of remaining hot water in the hot water tank 30. This transition prediction value is derived in units of time corresponding to the hot water consumption pattern (24 hours in the present embodiment).

  In FIG. 15, a predicted transition value of the remaining hot water amount of the hot water storage tank 30 derived using the actual remaining hot water amount without using the above-described offset remaining hot water amount is indicated by a thick line. The transition predicted value of the remaining hot water amount in the hot water storage tank 30 derived using this actual remaining hot water amount is derived in step 510 using the actual remaining hot water amount (estimated in step 106) instead of the offset remaining hot water amount. do it. A transition predicted value derived using the offset remaining hot water amount and a predicted transition value derived using the actual remaining hot water amount will be described in comparison. The transition predicted value derived using the offset remaining hot water amount is obtained by adding the offset amount to the transition predicted value derived using the actual remaining hot water amount. That is, in the transition prediction, even when it is estimated that the hot water is used up, the hot water can actually be left in the hot water storage tank 30 by an offset amount. Therefore, when the actual amount of remaining hot water is derived, the amount of remaining hot water reaches a predetermined amount (the heating start threshold of the auxiliary heating device 40) at time Ta, so that heating of the auxiliary heating device 40 is started. . On the other hand, when the amount of remaining hot water is derived, even if it is estimated that the hot water has been used up in the transition prediction at the time Ta, the amount of remaining hot water in the hot water storage tank 30 is actually at least an offset amount. Therefore, since the remaining hot water amount does not reach the predetermined amount, the heating start of the auxiliary heating device 40 can be suppressed. Thus, in the transition prediction of the offset remaining hot water amount, since the heating start of the auxiliary heating device 40 is anticipated, unnecessary heating of the auxiliary heating device 40 can be suppressed, and energy saving can be improved.

  The operation control device 50 derives an evaluation function J, which is an energy saving effect index value, in the operation plan based on the power generation stop time period set in Step 506 (Step 512). The operation control device 50 derives the evaluation function J from the predicted transition value Q [k] of the amount of remaining hot water in the hot water tank 30 derived in step 510, the power consumption pattern Eo read in step 502, and the following equation 5. In this evaluation function, J is a value obtained by adding the energy saving effect at each time for one day. For example, in the first calculation, the total energy saving effect for one day for the first combination 0:00 to 0:00 is derived. The evaluation function (energy saving effect index value) of the present embodiment is a reduction amount of primary energy (fuel supplied to the power generation apparatus 10). For example, when the power generation stop time period is 0:00 to 0:00, the evaluation function value is 19686 (J).

Here, J ₁ [k] is the energy saving effect at time k, Eo is the power consumption pattern, and Qfull is the maximum hot water tank heat quantity. b ₁ is an energy saving effect conversion value [J / W], b ₂ is an energy saving effect conversion value [J], and both values are calculated from experimental data obtained using an actual machine. c ₁ is the energy saving effect conversion value [J / W] when the hot water tank 30 is full in temperature, and c ₂ is the energy saving effect conversion value [J / W when the hot water tank 30 is full in temperature. These values are calculated from the experimental data obtained using the actual machine and the characteristics of the radiator 37.

  Qfull is derived by the following equation (6).

Here, Cp is the specific heat of water (4.189 × 10 ⁻³ [J / (kg · K)]), V is the volume of the hot water tank 30 (150 l = 150 kg in this embodiment), and Tmax is The exhaust heat recovery maximum temperature (for example, 70 ° C.), and Tw is the temperature of tap water.

  Then, the operation control device 50 associates the power generation stop time zone set in step 506 with the evaluation function value (energy saving effect index value) derived in step 512 and stores it in the storage device (step 514).

  The operation control device 50 repeatedly performs the above-described processing of Steps 506 to 514 for all combinations of the above-described power generation stop time zones (continues to determine “NO” in Step 516). When the association between the power generation stop time zone and the energy saving effect index value is completed for all the combinations, the operation control device 50 determines “YES” in step 516, and advances the program to step 518.

  In step 518, the operation control device 50 selects the one with the maximum energy saving effect index value from the association between the power generation stop time zone stored so far and the energy saving effect index value. FIG. 16 shows a relationship between the stored power generation stop time zone and the energy saving effect index value in a three-dimensional graph. In FIG. 16, the horizontal axis indicates the power generation stop time, and the vertical axis indicates the power generation start time. Both axes are shown in increments of 30 minutes from 0:00 to 24:00. The energy saving effect index values are indicated by contour lines. The range indicated by the contour line L1 is the range where the energy saving effect index value is the largest. The energy saving effect index value becomes smaller as going outward from the contour line L1.

  As is apparent from FIG. 16, when the stop time is 3: 0 to 5:00 and the start time is 16:00 to 18:00, the energy saving effect index value is maximized. The operation control device 50 derives, as an optimal operation plan, an operation plan having a power generation stoppage time period composed of a combination of a stop time 4:00 and a start time 17:00 that has the largest energy saving effect index value. To do. Then, the operation control device 50 updates and stores the derived operation plan (step 520).

  In step 112, the operation control device 50 derives and updates the operation plan, and then waits for the first predetermined time T1 to elapse to start the next operation plan derivation and update storage processing. .

  In addition to the above-described operation plan derivation and update storage processing, the operation control device 50 performs a power generation stop operation and a continuous power generation operation as shown in FIG. The operation of the power generator 10 is controlled by switching. The operation control device 50 repeatedly executes the processing of steps 602 to 608 every second predetermined time T2 (for example, every 60 seconds). The second predetermined time T2 is set to a relatively short time value, and is sufficiently smaller than the first predetermined time described above.

  Specifically, in step 602, the operation control device 50 determines whether or not the current time is the latest power generation stop time zone derived as described above. If the current time is the power generation stop time zone, operation controller 50 determines “YES” in step 602 and advances the program to step 604. In step 604, the operation control device 50 performs the power generation stop operation of the power generation device 10. That is, the operation control device 50 sets the power generation amount instruction value to 0 and stops the power generation of the power generation device 10.

  On the other hand, when the current time is not the power generation stop time zone (when it is the power generation operation time zone), “NO” is determined in step 602, and the program proceeds to step 606. In step 606, the operation control device 50 performs the continuous power generation operation of the power generation device 10. In other words, the operation control device 50 measures the power consumption by the wattmeter 22 every second predetermined time T2 (control cycle), and filters the measured power consumption. This filtering process is performed each time the power consumption is measured, and based on the measured data and stored data for the past several cases (four cases in the present embodiment), the following number 7 similar to the above number 1. The filtering process is executed.

  The operation control device 50 sets the filter processing value as the power generation amount instruction value, and instructs the power generator 11 of the power generation amount instruction value. As a result, the power generation apparatus 10 basically generates power by following the power consumption. And when the power consumption changes suddenly, it is possible to suppress the vibration of the power generation amount without changing the power generation amount abruptly according to the power consumption by the filter process, so that efficient power generation is possible. It becomes.

  According to the control described above, when the power consumption changes as shown in FIG. 17, the power generation is stopped from 4:00 to 17:00, so the power generation is zero. Electric power is generated following the power consumption between 0:00 and 4:00 and between 17:00 and 24:00. According to this operation plan, it is possible to obtain the maximum energy saving effect. In FIG. 17, the power consumption is indicated by a thick solid line, and the power generation is indicated by a thin thin line.

  As is clear from the above description, in this embodiment, the actual remaining hot water amount deriving means (step 106) derives the actual remaining hot water amount in the hot water storage tank 30, and the offset remaining hot water amount deriving means (step 108) Deriving the offset remaining hot water amount in the hot water tank 30 obtained by subtracting the offset amount from the actual remaining hot water amount in the hot water tank 30 derived by the actual remaining hot water amount deriving means, the operation plan deriving means (step 110) Based on the consumption pattern of the amount of power consumed by the device 21, the consumption pattern of the amount of hot water consumed by the hot water use devices (26a, 26b), and the offset remaining hot water amount derived by the offset remaining hot water amount deriving means. From the power generation stop time zone in which the power generation of the power generation device is stopped and the power generation operation time zone in which the continuous power generation operation of the power generation device 10 following the power consumption of the load device 21 is performed. To derive that operation plan. Then, the operation control device 50 controls the power generation device 10 according to the operation plan, and controls the power generation device 10 so that the power generation amount corresponds to the power generation amount instruction value.

  Thereby, by carrying out the operation plan derived using the offset remaining hot water amount obtained by subtracting the offset amount from the actual remaining hot water amount in the hot water tank 30, the remaining amount of hot water in the hot water tank 30 remains at least. It will be. That is, at least an offset amount can be secured for the remaining hot water amount in the hot water tank 30. Therefore, if this offset amount is set to a value larger than the heating start threshold value of the auxiliary heating device 40, the heating operation of the auxiliary heating device 40 is suppressed as much as possible even when the hot water in the hot water tank 30 is used up. Can do. Furthermore, the amount of remaining hot water can be increased by increasing the power generation operation time zone by the time corresponding to the offset amount without increasing the output power of the power generation apparatus 10 as in the prior art. Therefore, the burden on the power generation device 10 can be reduced by suppressing the power generation device 10 from operating at a relatively high power generation output. Thus, according to the cogeneration which concerns on this invention, the burden of the electric power generating apparatus 10 can be reduced, suppressing the useless operation of the auxiliary heating apparatus 40. FIG.

  Further, the offset amount is set to a value larger than a predetermined amount that is a heating start threshold value of the auxiliary heating device 40. As a result, the amount of hot water remaining in the hot water storage tank 30 can be reliably ensured to be greater than the heating start threshold value of the auxiliary heating device 40, and the auxiliary heating device 40 can be heated even when the hot water in the hot water storage tank 30 is used up. The operation can be suppressed as much as possible.

  The offset amount is set by learning from the usage amount per use in the actual hot water amount data used in the hot water usage devices 26a and 26b. As a result, even in the case of sudden use that is less than the offset amount and does not appear regularly in the consumption pattern of hot water (for example, using hot water to gargle), such usage is reduced. Can be covered with an offset amount. In this case, since the offset amount can be set according to the amount of use once, the operation of the auxiliary heating device 40 can be suppressed as much as possible even when suddenly using a small amount of hot water, and energy saving is improved. Can be made.

  Further, in the relationship between the offset amount obtained when the offset amount is increased from 0 and the energy amount consumed for the heating operation of the auxiliary heating device 40, it is consumed for the heating operation of the auxiliary heating device 40. The offset amount when the amount of energy to be used becomes constant from the decrease is set to the offset amount used in the offset residual hot water amount deriving means (step 108). As a result, the offset amount having the highest energy saving amount for each of the energy consumed by the auxiliary heating device 40 and the energy for generating hot water for the offset amount can be used, so that the entire cogeneration system can save energy. Can be kept high.

  The present invention can also be applied to a hot water storage system. As a hot water storage system, there is a system having a hot water storage tank using electric power such as nighttime electric power or eco-cute, a hot water storage tank using solar heat, and a hot water storage tank using a gas water heater in addition to the above-described cogeneration system. In this case, the hot water storage system includes a hot water generating device (the power generator 11 of the above-described embodiment) that generates hot water, and a hot water storage tank that stores the hot water and supplies the hot water to the hot water use device (of the above-described embodiment). A hot water storage tank 30), a temperature sensor (a plurality of temperature sensors 34-1 to 34-10 in the embodiment described above) that is provided in the vertical direction in the hot water storage tank and detects the temperature of the hot water at that position, and a hot water generator And an operation control device (operation control device 50 of the above-described embodiment) that controls the hot water storage tank. Moreover, this invention is applicable also to the hot water storage tank without an auxiliary heating apparatus.

  In this case, as in the embodiment described above, the actual remaining hot water amount deriving means derives the actual remaining hot water amount in the hot water storage tank, and the offset remaining hot water amount deriving means is derived from the actual remaining hot water amount deriving means in the hot water tank. The amount of offset remaining hot water in the hot water tank obtained by subtracting the offset amount from the actual remaining amount of hot water is derived, and the operation plan deriving means uses the consumption pattern of the amount of hot water consumed by the hot water use device, and the offset remaining hot water amount deriving means. The operation plan of the hot water generator is derived based on the amount of offset remaining hot water derived in (1). Then, the operation control device controls the hot water generation device and the hot water storage tank according to the operation plan.

  As a result, by carrying out the operation plan derived using the offset remaining hot water amount obtained by subtracting the offset amount from the actual remaining hot water amount in the hot water tank, the remaining hot water amount in the hot water tank is at least offset. Become. That is, at least an offset amount can be secured for the amount of hot water remaining in the hot water tank. Therefore, if the offset amount is set to a value larger than the heating start threshold value of the auxiliary heating device, the heating operation of the auxiliary heating device can be suppressed as much as possible even when the hot water in the hot water tank is used up. As a result, the offset amount can be set appropriately, and the auxiliary heating device itself need not be provided, so that the price of the system can be reduced.

  Moreover, in embodiment mentioned above, the auxiliary heating apparatus 40 is provided in the auxiliary heating circuit 41, and when the amount of remaining hot water of the hot water storage tank 30 becomes below a predetermined amount, it assists the low temperature hot water of the vertical center part of the hot water storage tank 30. Although it heated with the heating apparatus 40 and returned to the upper part of the hot water storage tank 30, you may make it provide the auxiliary heating apparatus 40 in the hot water supply pipe 35 (refer FIG. 18).

  In the hot water supply pipe 35, an auxiliary heating device 40, a temperature sensor (not shown), and a flow rate sensor 36 are arranged in order from the upstream. The temperature sensor detects the temperature of the hot water after passing through the auxiliary heating device 40, and the detection signal is transmitted to the operation control device 50. That is, the operation control device 50 heats the auxiliary heating device 40 so that the temperature of the hot water detected by the temperature sensor becomes the set hot water temperature. Therefore, when the amount of remaining hot water in the hot water storage tank 30 becomes a predetermined amount or less, the auxiliary heating device 40 heats the remaining hot water. Although not shown, tap water from the water supply device 14 joins the hot water supply pipe 35 between the outlet of the hot water tank 30 and the temperature sensor. Thereby, the temperature of the hot water from the hot water tank 30 is lowered. In addition, you may make it control the auxiliary | assistant heating apparatus 40 based on the temperature detected with the temperature sensor of the hot water tank 30 instead of the temperature detected after passing the auxiliary | assistant heating apparatus 40. FIG.

In the above-described embodiment, the energy amount is increased as an index of the energy saving effect, but other indexes (for example, CO ₂ reduction amount, household utility cost) may be adopted. Further, as the power generation device 10, there is a power generation device 11 in which the power generator 11 generates AC power and directly outputs it without going through the exchanger 12.

It is a schematic diagram showing an outline of one embodiment of a cogeneration system according to the present invention. It is a flowchart of the control program performed with the operation control apparatus shown in FIG. It is a flowchart of the power consumption pattern creation routine performed with the operation control apparatus shown in FIG. It is a flowchart of the hot water consumption pattern creation routine performed with the operation control apparatus shown in FIG. It is a flowchart of the hot water storage tank remaining hot water amount estimation routine performed with the operation control apparatus shown in FIG. 2 is a flowchart of an operation plan derivation / update storage routine executed by the operation control device shown in FIG. It is a flowchart of the control program performed with the operation control apparatus shown in FIG. It is a figure which shows matrix Eo_temp. It is a figure which shows the update condition of matrix Eo_temp. It is the figure which showed the power consumption prediction value with the matrix. The relationship between the offset amount and the amount of energy consumed for the heating operation of the auxiliary heating device (input fuel amount) is indicated by a thin line, and the relationship between the offset amount and the energy saving amount of the entire cogeneration is indicated by a thick line. is there. It is a graph which shows an example of a power consumption pattern. It is a graph which shows an example of the hot water consumption pattern. It is a graph which shows the predicted value of the waste heat recovery amount when the operation plan whose power generation stoppage time period is from 4:00 to 17:00 is derived as an optimal operation plan. When an operation plan in which the power generation stoppage time period is from 4:00 to 17:00 is derived as an optimal operation plan, the remaining hot water amount prediction value derived using the actual remaining hot water amount (indicated by a thick line) 4 is a graph showing a predicted remaining hot water amount (indicated by a thin line) derived using the offset remaining hot water amount. It is a graph which shows an example of the relationship between the stop time and start time of a power generation stop time zone, and an energy saving effect index value. It is a graph which shows the electric power consumption and electric power generation which are fluctuate | varied. It is a figure which shows the other Example which provided the auxiliary heating apparatus in the hot water supply pipe.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Power generation device, 10a ... Wattmeter, 11 ... Generator, 12 ... Converter, 13 ... Fuel supply device, 13a ... Flow meter, 14 ... Water supply device, 15 ... Transmission line, 16 ... System power supply, 21 ... Load Apparatus, 26a ... Hot water use device, 26b ... Heat use device, 30 ... Hot water storage tank, 34 ... Temperature sensor group, 36 ... Flow rate sensor, 40 ... Auxiliary heating device, 50 ... Operation control device.

Claims (4)

A power generator for supplying power to the load device;
A hot water storage tank for storing hot water recovered from the exhaust heat of the power generation device and supplying the hot water to the hot water use device;
An operation control device that controls the power generation device according to an operation plan and controls the power generation device so as to have a power generation amount corresponding to a power generation amount instruction value;
When the amount of remaining hot water in the hot water storage tank is equal to or less than a predetermined amount, an auxiliary heating device that introduces and heats hot water in the hot water storage tank, and
With
The operation control device includes:
An actual remaining hot water amount deriving means for deriving an actual remaining hot water amount in the hot water storage tank;
Offset residual hot water amount derivation means for deriving an offset residual hot water amount in the hot water tank obtained by subtracting an offset amount from the actual residual hot water amount in the hot water tank derived by the actual residual hot water amount derivation means;
Based on the consumption pattern of the amount of power consumed by the load device, the consumption pattern of the amount of hot water consumed by the hot water usage device, and the amount of remaining hot water derived by the offset remaining hot water amount deriving means, the power generation of the power generation device An operation plan deriving means for deriving the operation plan consisting of a power generation stop time zone in which the power generation device is stopped and a power generation operation time zone in which continuous power generation operation of the power generation device following the power consumption of the load device is performed;
Equipped with a,
The cogeneration system is characterized in that the offset amount is set to a value larger than the predetermined amount which is a heating start threshold of the auxiliary heating device . Oite to claim 1, wherein the offset amount is cogeneration system characterized by being set by learning from usage per use of the actual hot water amount of data used in the hot water used device . 3. The auxiliary heating device according to claim 1 , wherein, in the relationship between the offset amount and the amount of energy consumed for the heating operation of the auxiliary heating device, obtained when the offset amount is increased from 0, The cogeneration system is characterized in that an offset amount when the amount of energy consumed for the heating operation becomes constant from a decrease is set as the offset amount. A hot water generator for generating hot water;
A hot water storage tank for storing the hot water and supplying the hot water to a hot water use device;
An operation control device for controlling the hot water generator and the hot water storage tank;
When the amount of remaining hot water in the hot water storage tank is equal to or less than a predetermined amount, an auxiliary heating device that introduces and heats hot water in the hot water storage tank, and
With
The operation control device includes:
An actual remaining hot water amount deriving means for deriving an actual remaining hot water amount in the hot water storage tank;
Offset residual hot water amount derivation means for deriving an offset residual hot water amount in the hot water tank obtained by subtracting an offset amount from the actual residual hot water amount in the hot water tank derived by the actual residual hot water amount derivation means;
An operation plan deriving unit for deriving an operation plan for the hot water generation device based on a consumption pattern of the amount of hot water consumed in the hot water use device and an offset remaining hot water amount derived by the offset remaining hot water amount deriving unit;
Equipped with a,
The hot water storage system according to claim 1, wherein the offset amount is set to a value larger than the predetermined amount which is a heating start threshold of the auxiliary heating device .

Images