JP2004324545A - Cogeneration device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve a thermal efficiency of an engine, and to improve a space saving efficiency and installability. <P>SOLUTION: For example, this cogeneration device comprises, integrally in a casing 5, a generator 11 connected to the engine 10 via a variable speed transmission mechanism 15, a first compressor 23 driven by a driving force of the engine 10, and a second compressor 28 driven by an electric power. The revolution speed of the engine 10 is controlled based on the load on the first compressor 23, an output for making the thermal efficiency of the engine 10 at the revolution speed become the maximum thermal efficiency is calculated based on a table map 40. Since the generator 11 is operated while the variable speed transmission mechanism 15 is controlled to have a load corresponding to the excess output of the output of the engine 10 to the first compressor 23, the thermal efficiency of the engine 10 is improved. Also, since there is no need to install an indoor unit for a refrigerator 2, the space-saving efficiency and the installabilty are improved. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a compressor provided with an engine, and a compressor driven by the engine, and a combined heat and power supply device connected to a generator driven by the engine to supply power and supply cold energy.
[0002]
[Prior art]
A conventional cogeneration system includes an engine and a generator driven by the driving force of the engine. The engine is operated to drive the generator, and the electric power generated by the generator is supplied to a commercial power supply. Power supply is performed in cooperation with the grid, leveling power consumption by reducing power peaks in the daytime, reducing the burden of power charges on users, and further discharging exhaust gas of engine and cooling water. Recovers hot water through a water heat exchanger or the like.For example, in a property that has hot water supply demand, the energy saving effect of storing the hot water in a hot water storage tank for hot water supply and performing hot water supply according to the hot water supply demand is obtained. Had brought.
[0003]
In such a cogeneration system, the engine and the generator are directly connected, and the engine and the compressor are connected via a drive transmission mechanism that intermittently connects the generator and the generator, and power is generated by the generator. In order to keep the power generation constant, the engine is operated at a constant rotation speed. On the other hand, in the compressor, the drive transmission mechanism performs an intermittent operation of the compressor to perform an operation according to an air conditioning load.
[0004]
Further, in this cogeneration system, fuel is burned in the engine, a part of the heat energy is converted into driving force, and the generator is operated to generate power generation. The amount of heat supply that can be recovered from the engine is much larger than the amount of electric power supplied from the engine, making it difficult to introduce the heat supply into a property that does not require hot water supply.
[0005]
For this reason, in a property that does not have the hot water supply demand, the heat supply amount recovered from the engine is used as a heat source of an air conditioner that is operated using heat of a desiccant air conditioner or an absorption refrigerator. In addition, a cogeneration system for performing an air-conditioning operation has been proposed, and an energy saving effect has been brought about similarly to the cogeneration system for supplying the electric power and the hot water. (For example, see Patent Document 1)
[0006]
[Patent Document 1]
JP 2001-324240 A (Page 3-5, FIG. 1)
[0007]
[Problems to be solved by the invention]
However, in the cogeneration system as disclosed in Patent Document 1, even if the number of revolutions at which the generator is operated by the engine is designed to be the highest efficiency point of the engine, the air conditioning operation of the compressor is not performed. By setting the drive transmission mechanism in the connected state in order to perform the operation, the balance between the output of the engine at the rotation speed and the loads of the generator and the compressor is lost. There was a problem that the operation was performed at a point outside the efficiency point.
[0008]
Also, in stores such as supermarkets and convenience stores, it is necessary to install a refrigeration refrigerator for cooling and preserving food and the like in addition to air conditioning even if the cogeneration system is installed. Even if the power consumption can be reduced by installation, the outdoor unit of the refrigerator must be separately installed, and there is also a problem that the installation space of the outdoor unit and the installation work must be separately performed. Was.
[0009]
Therefore, an object of the present invention is to provide a combined heat and power supply device that improves the thermal efficiency of an engine, and also improves space saving and installation workability.
[0010]
[Means for Solving the Problems]
The invention according to claim 1 includes a power supply generator connected to one end of the engine via a variable speed transmission mechanism, and a compression for cold heat supply driven to the other end by the driving force of the engine. In the combined heat and power supply device that connects the compressor and is provided in the same housing, and supplies electric power and cold heat, the number of revolutions of the engine is controlled according to the load of the compressor, and the number of revolutions at the number of revolutions is controlled. The output of the engine at which the thermal efficiency becomes the highest thermal efficiency is calculated, the surplus output of the engine output applied to the compressor is calculated, and the number of revolutions of the generator is controlled so as to have a load corresponding to the surplus output. And a control means for performing the control.
[0011]
According to a second aspect of the present invention, in the first aspect, when the surplus output decreases, the control means reduces the load on the generator by reducing the speed by the variable speed transmission mechanism. When the surplus output increases, the speed is increased by the variable speed transmission mechanism to increase the load on the generator.
[0012]
According to a third aspect of the present invention, in the first or second aspect, the control means includes a table map containing data of the number of revolutions, output, and thermal efficiency of the engine, and based on the table map. And calculating the output and thermal efficiency of the engine at the rotation speed.
[0013]
According to a fourth aspect of the present invention, in any one of the first to third aspects, a compressor driven by electric power is provided in the housing, and the electric power generated by the electric generator is connected to be used. It is characterized by having done.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to FIGS.
[0015]
A first embodiment of a cogeneration system that improves the thermal efficiency of an engine according to the present invention and also improves space saving and installation workability will be described. First, as shown in FIG. 1, a refrigerator 2 for cooling and preserving foods and the like, a desiccant air conditioner 3, and an indoor unit 4 are connected to a cogeneration system 1 and provided, for example, in a single-phase mode. The cogeneration system 1 is connected by a power supply line 34 to a commercial power supply, which is a 3-wire 100V power line power supply system. The cogeneration system 1 mainly includes a power generation unit 6, a heat recovery unit 7, a first refrigeration circuit unit 8, and a second refrigeration circuit unit 9 housed in a housing 5. The power line power supply system is connected to a light load (not shown).
[0016]
The power generation unit 6 is driven by the driving force of the engine 10, and includes a generator 11 having a variable speed transmission mechanism 15 such as a CVT that is variably controlled by a control unit 34, which will be described later, and power generated by the generator 11. A system linking device 12 for system-linking and outputting power to the power line power supply system, a power supply line 13 for supplying power output from the system linking device 12 to the commercial power supply, and a phase of the power line power supply system , And a power supply sensor 14 for detecting the direction of the power supplied from the system cooperation device 12. The generator 11 is connected to one end of the engine 10. The system cooperation device 12 is configured to supply power to the power line power system as a single-phase three-wire system 100V, and to supply power between the R phase, the S phase, the S phase, and the T phase in the drawing. , And a single-phase 200V power supply between the R-phase and the T-phase.
[0017]
The heat recovery unit 7 includes an exhaust heat exchanger 16 that recovers heat from exhaust gas from the engine 10, an exhaust top 17 that discharges the exhaust gas to the atmosphere, a cooling water pump 18 that circulates the cooling water, A water heat exchanger 19 for supplying heat to the desiccant air conditioner 3, a radiator 20 for radiating excess heat from the water heat exchanger 19 to the atmosphere, and a circulation of the cooling water based on a temperature of the cooling water. It comprises a first three-way valve 21 and a second three-way valve 22 for switching the path.
[0018]
The first refrigeration circuit unit 8 includes a first compressor 23 that is driven by the driving force of the engine 10 to compress the refrigerant, and a first four-way valve that reverses the circulation direction of the refrigerant discharged from the first compressor 23. 24, a first outdoor heat exchanger 25 for exchanging heat between the refrigerant and the atmosphere, a first pressure reducing valve 26 for depressurizing the refrigerant, and gas-liquid separation of the refrigerant circulated through the indoor unit 4 and returned. And a first accumulator 27 for performing the above-mentioned operations are connected by a refrigerant pipe.
[0019]
The second refrigeration circuit unit 9 includes a second compressor 28 driven by electric power to compress the refrigerant, a second four-way valve 29 for reversing the circulation direction of the refrigerant discharged from the second compressor 28, A second outdoor heat exchanger 30 for exchanging heat with the atmosphere, a second pressure reducing valve 31 for reducing the pressure of the refrigerant, and a second accumulator for separating the refrigerant returned by circulating through the refrigerator 2 32 are connected by a refrigerant pipe. The second compressor 28 may be a compressor that is operated with a capacitor or a compressor that is operated with a variable capacity by including an inverter.
[0020]
The power of the second compressor 28 is supplied to both phases of the power supply line 13 connected from the output side of the system linking device 12 to the power line power system, that is, the R phase in the figure, the T phase, The power supply sensor 14 is connected to the single-phase 200V side between the power supply line 13 and the power line 14 on the power supply line 13 from a position where the power supply of the second compressor 28 is connected. It is provided at a position on the power supply system side.
[0021]
Further, a control unit 34 for controlling the power generation unit 6, the heat recovery unit 7, the first refrigeration circuit unit 8, the second refrigeration circuit unit 9, and the engine 10 is built in the housing 5.
[0022]
The refrigerator 2 is provided with a second indoor heat exchanger 36 connected to the second refrigeration circuit section 9, and the indoor unit 4 is provided with a first indoor heat exchange connected to the first refrigeration circuit section 8. A device 35 and an indoor temperature sensor 37 are provided.
[0023]
As shown in FIG. 2, the control unit 34 is provided with a table map 40 in which the output of the engine 10 and the data of the thermal efficiency at each rotation speed of the engine 10 are recorded, and based on this table map. The power generation unit 6 is controlled by the control unit 34.
[0024]
The operation of the cogeneration system 1 will be described. First, when the operation of the indoor unit 4 is started, the temperature of the room in which the indoor unit 4 is installed is detected by the indoor temperature sensor 37, and the indoor unit 4 (not shown) is detected. The air-conditioning load KH1 is calculated by the indoor control unit, and an instruction to start the operation of the air-conditioning load KH1 and the engine 10 is transmitted to the control unit 34 via a communication line (not shown). The control unit 34 that has received the transmission from the indoor unit 4 calculates the operating capacity of the compressor 23 from the transmitted air conditioning load KH1 to determine the rotation speed R1 of the engine 10, and determines the rotation speed R1 of the engine 10. The compressor load HC1 at R1 is calculated. At the same time, based on the table map 40 provided in the control unit 34, an output P1 that becomes the maximum thermal efficiency MTH1 at the rotation speed R1 of the engine 10 is calculated, and the output P1 and the compressor load HC1 are calculated. The surplus output Ps1 of the engine 10 is calculated from the difference. Then, the control unit 34 controls the variable speed transmission mechanism 15 so that the load HO1 of the generator 11 becomes a load corresponding to the surplus output Ps1, and starts the operation of the engine 10.
[0025]
Thereby, as shown in FIG. 1, the compressor 23 is driven by the driving force of the engine 10, and when the indoor unit 4 is in the cooling operation, the refrigerant discharged from the compressor 23 operates the first four-way valve 24. Then, the refrigerant flows into the first outdoor heat exchanger 25 via the first outdoor heat exchanger 25, where the refrigerant exchanges heat with the outside air to be condensed, and is decompressed by the first pressure reducing valve 26 to be decompressed by the indoor unit 4 Flows into the indoor heat exchanger 35. Thereafter, the refrigerant exchanges heat with the indoor air in the indoor heat exchanger 35 to evaporate the refrigerant, and circulates again through the first four-way valve 24, through the first accumulator 27, and back to the first compressor 23. Then, the room is cooled.
[0026]
Further, since the variable speed transmission mechanism 15 of the generator 11 is controlled by the control unit 34 to be the load HO1 corresponding to the surplus output Ps1 of the engine 10, the generator 11 generates the amount of power generation corresponding to the load HO1. Based on the phase and the direction of the electric power detected by the electric power supply sensor 14, the electric power is converted into a commercial power supply (for example, the above-mentioned three-phase, AC 100 V) by the system cooperation device 12, Supplied to.
[0027]
When the air-conditioning load HK1 of the indoor unit 4 decreases and becomes the air-conditioning load HK2, the air-conditioning load HK2 is transmitted from the indoor unit 4 to the control unit 34 of the cogeneration system 1 via a communication line (not shown), The control unit 34 having received this transmission again calculates the operating capacity of the compressor 23 from the air-conditioning load HK2, determines the rotational speed R2 of the engine 10, and sets the compressor at the rotational speed R1 of the engine 10 at the rotational speed R1. The load HC2 is calculated. At the same time, based on the table map 40 provided in the control unit 34, an output P2 that becomes the maximum thermal efficiency MTH2 at the rotation speed R2 of the engine 10 is calculated, and a difference between the output P2 and the compressor load HC2 is calculated. Is used to calculate the surplus output Ps2 of the engine 10. Then, the control unit 34 controls the variable speed transmission mechanism 15 so that the load HO2 of the generator 11 becomes a load corresponding to the surplus output Ps2, and continues the operation of the engine 10.
[0028]
As a result, the rotation speed of the engine 10 decreases, and the amount of refrigerant discharged from the compressor 23 decreases. Therefore, the amount of refrigerant condensed in the first outdoor heat exchanger 25 also decreases, and the amount of refrigerant circulating to the indoor unit 4 also decreases. The cooling capacity of the indoor unit 4 is also reduced.
[0029]
Further, since the variable speed transmission mechanism 15 of the generator 11 is controlled by the control unit 34 so as to be the load HO2 corresponding to the surplus output Ps2 of the engine 10, the generator 11 generates the amount of power generation corresponding to the load HO2. Based on the phase and the direction of the electric power detected by the electric power supply sensor 14, the electric power is converted into a commercial power supply (for example, the above-mentioned three-phase, AC 100 V) by the system cooperation device 12, Supplied to.
[0030]
The above description will be described with reference to the table map 40. As shown in FIG. 3, the rotation speed R1 of the engine 10 is determined from the air conditioning load HK1 of the indoor unit 4, and the compressor load HC1 at the rotation speed R1 is reduced. When the calculation is performed, assuming that the rotation speed R1 of the engine 10 is, for example, 1800 rpm and the compressor load HC1 is at the position of the point A, the output that becomes the maximum thermal efficiency MTH1 when the rotation speed R1 of the engine 10 is 1800 rpm. P1 is calculated based on the data recorded in the table map 40. Thereafter, the surplus output Ps1 of the engine 10 is calculated from the difference between the output P1 and the compressor load HC1, and the control unit 34 determines that the load HO1 of the generator 11 becomes a load corresponding to the surplus output Ps1. The transmission mechanism 15 is controlled. Thus, the air conditioning operation corresponding to the air conditioning load HK1 of the indoor unit 4 can be performed, and the engine 10 can be operated at the maximum thermal efficiency MTH1.
[0031]
Then, the air conditioning load HK1 of the indoor unit 4 decreases and becomes the air conditioning load HK2. For example, when the rotation speed R2 of the engine 10 becomes 1500 rpm from the air conditioning load HK2, the compressor load HC2 is located at the point B. Then, the output P2 that becomes the maximum thermal efficiency MTH2 when the rotation speed R2 of the engine 10 is 1500 rpm is calculated based on the data recorded in the table data 40. Thereafter, the surplus output Ps2 of the engine 10 is calculated from the difference between the output P2 and the compressor load HC2, and the control unit 34 determines that the load HO2 of the generator 11 becomes a load corresponding to the surplus output Ps2. The transmission mechanism 15 is controlled. Thus, the air conditioning operation corresponding to the air conditioning load HK2 of the indoor unit 4 can be performed, and the engine 10 can be operated at the maximum thermal efficiency MTH2.
[0032]
Further, in the cogeneration system 1, as shown in FIG. 1 described above, a second refrigerant system 9 having a second compressor 28 driven by the electric power of the commercial power supply is provided. Is connected to a refrigerant heat exchanger 36 of the refrigerator 2 that performs freezing and refrigeration and heating of foods and the like. In the second refrigerant system 9, when the refrigerator 2 performs freezing and refrigeration of food, the refrigerant compressed by the second compressor 28 is passed through the second four-way valve 29 to the second outdoor heat exchanger. The refrigerant is condensed by the second outdoor heat exchanger 30, decompressed by the second pressure reducing valve 31, and flows into the refrigerant heat exchanger 36 of the refrigerator 2. Thereafter, the refrigerant evaporates in the refrigerant heat exchanger 36 to perform freezing and refrigeration of the food and the like, and returns to the second compressor 28 via the second accumulator 32 via the second four-way valve 29. Circulate.
[0033]
When the refrigerator 2 heats food, the refrigerant compressed by the second compressor 28 flows into the refrigerant heat exchanger 36 of the refrigerator 2 via the second four-way valve 29. Then, the refrigerant is condensed in the refrigerant heat exchanger 36 to heat the food, the pressure is reduced by the second pressure reducing valve 31, and the refrigerant is condensed in the second outdoor heat exchanger 30, and the second four-way valve is formed. The air circulates through a path returning to the second compressor 28 through the second accumulator 32 via the second accumulator 32.
[0034]
Here, since the power line that supplies power to the second compressor 28 is connected to the power supply line 13, that is, the output side of the system cooperation device 12, when the engine 10 is operating, The power generated by the generator 11 can be used preferentially to perform freezing and refrigeration or heating of the food or the like, and when the engine 10 is stopped, the power of the commercial power supply is used. It is possible to perform the operation of freezing and refrigeration or heating of the food or the like.
[0035]
That is, for example, in summer, during the daytime when the air-conditioning load increases, the engine 10 is operated, power is generated by the generator 11, and power is supplied to the power line power supply system. The power supplied from the power line power supply system consumed by the compressor 28 is reduced, and during the night when the air conditioning load is reduced, the second compressor 28 is operated with the power supplied from the power line power supply system.
[0036]
As described above, the control unit 34 is provided with the table map 40 in which the data of the thermal efficiency of the engine 10 is recorded, and the variable speed transmission mechanism 15 is controlled based on the table map 40 so that the power generation by the generator 11 is performed. Since the engine 10 can be operated with the best thermal efficiency, economical air-conditioning operation can be performed, and an outdoor unit of the refrigerator 2 is newly installed, and this outdoor unit is connected to a commercial power supply system. Since installation work is not required, space saving and installation workability are improved.
[0037]
Further, such a cogeneration device may be a cogeneration device 50 as shown in the second embodiment in FIG.
[0038]
In the combined heat and power supply device 50 of the second embodiment, the refrigerant discharged from the first compressor 23 of the first refrigerant system 8 and the second compressor 28 of the second refrigerant system 9 are different from the first embodiment. And refrigerant circulated to the refrigerant system 51, and the refrigerant system 51 is connected to the refrigerator 2. The air conditioning of the room is performed by the desiccant air conditioner 3. I have.
[0039]
In the second embodiment, the second compressor 28 is provided as a compressor such as an inverter capable of changing its capacity, and a timer a is provided in the control unit 34 to determine whether or not it is time to use the nighttime power. Then, the first compressor 23 and the second compressor 28 connected to the refrigerant system 51 are respectively controlled to perform freezing / refrigeration or heating of the food or the like in the refrigerator 2.
[0040]
For example, when the timer a provided in the control unit 34 determines that the time period is other than the time period during which nighttime power is available, the control unit 34 stops the second compressor 28 and operates the engine 10. Then, the first compressor 23 is operated, and the first compressor 23 is operated at a capacity corresponding to the refrigerating load of the refrigerator 2. That is, the rotation speed of the engine 10 is controlled according to the refrigerating load of the refrigerator 2. At the same time, based on the table map 40 provided in the control unit 34, the output P at the highest thermal efficiency MTH of the engine 10 is calculated, and the compressor load HC of the first compressor 23 is calculated. The surplus output Ps of the engine 10 is calculated from the compressor load HC. Thereafter, the variable speed transmission mechanism 15 is controlled by the control unit 34 so that the load HO of the generator 11 becomes a load corresponding to the surplus output Ps, and the generator 11 performs power generation to perform the power line power supply. Power is supplied to a light load connected to the grid. As a result, the engine 10 can be operated with the best thermal efficiency, the power consumption during the day can be reduced, and the refrigerator 2 can be operated with little power supplied from the power line power system. Driving can be performed.
[0041]
On the other hand, when the timer a provided in the control unit 34 determines that the time period is during which nighttime power can be used, the control unit 34 stops the engine 10 and the generator 11 and the first compressor The operation of the second compressor 28 is started while the operation of the second compressor 28 is stopped. Thereby, the refrigerator 2 can be operated using the nighttime electric power whose usage fee is low.
[0042]
In the present embodiment, the control unit 34 is provided with the table map 40 in which the data of the thermal efficiency of the engine 10 is recorded, and the load on the engine 10 of the generator 11 is controlled based on the table map 40. However, the present invention is not limited to this. It is also possible to provide a pressure sensor (vacuum or boost) on the intake side of the engine 10 and perform the operation based on a pressure signal detected by the pressure sensor. It is also possible to detect the opening of the throttle to be performed and perform the operation based on the throttle opening signal.
[0043]
【The invention's effect】
From the above description, it is provided with the compressor and the generator driven by the driving force of the engine, and while controlling the rotation speed of the engine according to the load of the compressor, the thermal efficiency of the engine at the rotation speed is reduced. By calculating the output having the highest thermal efficiency and controlling the generator so as to provide a load corresponding to the surplus output of the engine applied to the compressor, the thermal efficiency of the engine is improved.
[0044]
Furthermore, by providing a built-in second compressor driven by electric power, there is no need to install an outdoor unit for operating the refrigerator, so that the installation space can be reduced and installation workability can be improved. it can.
[Brief description of the drawings]
FIG. 1 is a configuration diagram showing a cogeneration system including a first compressor driven by an engine of the present invention and a second compressor driven by electric power.
FIG. 2 is a diagram showing a table map provided in a control unit.
FIG. 3 is a diagram showing the operation of the cogeneration system on the table map.
FIG. 4 is a configuration diagram showing a cogeneration system in which energy saving of the cogeneration system of FIG. 1 is advanced.
[Explanation of symbols]
REFERENCE SIGNS LIST 1 cogeneration system 2 refrigerator 5 housing 6 power generation unit 8 first refrigerant circuit unit 9 second refrigerant circuit unit 10 engine 11 power generator 12 system cooperation device 13 power supply line 14 power supply sensor 15 variable speed transmission mechanism 23 first Compressor 24 First four-way valve 25 First outdoor heat exchanger 26 First pressure reducing valve 27 First accumulator 34 Control unit 35 First indoor heat exchanger 36 Second indoor heat exchanger 37 Indoor temperature sensor 50 Heat transfer supply device 51 Refrigerant system

Claims (4)

One end of the engine is provided with a generator for power supply connected via a variable speed transmission mechanism, and the other end is connected to a compressor for cold heat supply driven by the driving force of the engine. In the combined heat and power supply that performs power supply and cold heat supply, the number of revolutions of the engine is controlled according to the load of the compressor, and the heat efficiency at the number of revolutions of the engine is the highest. Control means for calculating the output, calculating the surplus output of the engine output applied to the compressor, and controlling the number of revolutions of the generator so as to provide a load corresponding to the surplus output. Combined heat and power equipment. The control means reduces the load on the generator by decelerating with the variable speed transmission mechanism when the surplus output decreases, and increases with the variable speed transmission mechanism when the surplus output increases. The heat transfer device according to claim 1, wherein the load of the generator is increased at a high speed. The control means includes a table map recording data of the engine speed, output and thermal efficiency, and calculates the output and thermal efficiency of the engine at the engine speed based on the table map. The cogeneration system according to claim 1. The air conditioner according to any one of claims 1 to 3, wherein a compressor driven by electric power is provided in the housing, and the electric power generated by the generator is connected to be usable.

Images