JP2003207226A - Cogeneration system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cogeneration system utilizing exhaust heat capable of increasing a use-side temperature, and being not limited in its use. <P>SOLUTION: The exhaust heat of an external heat source is guided to a heat source-side heat exchanger 7, the exhaust heat is recovered by the heat source-side heat exchanger 7 to heat a heat carrying medium, the heat carrying medium is compressed by a compressor 11, successively guided to a use-side heat exchanger 14 and a pressure reducing device 15, and circulated in the heat source-side heat exchanger 7. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cogeneration system utilizing exhaust heat of an external heat source such as engine cooling water.

[0002]

2. Description of the Related Art Generally, engine cooling water is introduced into a heat exchanger, water is supplied to the heat exchanger through a hot water pump, and the water is heated by the cooling water in the heat exchanger to store a hot water tank or the like. A cogeneration system is known in which heat is transferred to the user side.

[0003]

In this type of cogeneration system, the temperature level of the hot water on the user side does not reach the temperature level on the cooling water side or higher, and the cooling water temperature is usually 85 ° C. or lower. Therefore, the hot water temperature on the use side is about 75 ° C. or less, and the application is limited.

Therefore, an object of the present invention is to solve the above-mentioned problems of the prior art, to raise the temperature on the user side, and to provide a cogeneration system utilizing exhaust heat which is not restricted in its use. To provide.

[0005]

The invention according to claim 1 is
The exhaust heat of the external heat source is guided to the heat source side heat exchanger, the heat source side heat exchanger recovers the exhaust heat and heats the heat carrier medium, and the heat carrier medium is compressed by the compressor to use side heat exchange. A heat transfer cycle in which the heat transfer cycle is introduced into the heat exchanger on the heat source side, and the heat transfer cycle is introduced into the heat exchanger on the heat source side.

According to a second aspect of the present invention, according to the first aspect, the suction side of the compressor is provided with an accumulator, the discharge side of the compressor is provided with an oil separator, and the accumulator, the compressor and the oil separator are designed to have a high pressure. It is characterized by having a structure.

The invention according to claim 3 is the invention according to claim 1 or 2.
In the described one, the exhaust heat is exhaust heat of an engine for driving a generator, the exhaust heat is recovered by engine cooling water, and a part of the cooling water pipe is wound around the compressor. And

The invention according to claim 4 is the same as claims 1 to 3.
In any one of the above items, the exhaust heat is exhaust heat of an engine for driving a generator, and a control means for supplying electric power of the generator to the compressor is provided.

The present invention as defined in claim 5 is any one of claims 1 to 4.
In any one of the above items, the utilization side heat exchanger is wound around a hot water storage tank.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a circuit diagram of a cogeneration system according to this embodiment.

In FIG. 1, reference numeral 1 indicates an engine,
The engine 1 drives a generator 2, and the electricity generated here is supplied to a load via a power control device 3 or a control device 4 such as an inverter.

The engine 1 is provided with an exhaust gas heat exchanger 5, and the cooling water of the engine 1 is guided to the exhaust gas heat exchanger 5 where it is heated and then passes through a wax type switching valve 9 to
It is circulated through either the air heat exchanger 6 or the water-to-refrigerant heat exchanger 7, and returned to the engine 1 via the pump 8. The above is the basic circuit on the primary side (heat source side).

On the other hand, a refrigeration cycle (heat transfer cycle) 10 is provided as a secondary side (use side) circuit.
The refrigeration cycle 10 includes a compressor 11, an oil separator 12, a utilization side heat exchanger (condenser) 14 wound around an outer circumference of a hot water storage tank 13, a pressure reducing device 15, and the water-to-refrigerant heat exchanger ( An evaporator 7 and an accumulator 16 are provided.

The compressor 11, the oil separator 12, and the accumulator 16 are manufactured to withstand a high pressure design pressure based on the High Pressure Gas Safety Act, and have a high pressure design structure that can withstand a temperature level higher than the outside air temperature.

In this case, since the low pressure of the refrigeration cycle 10 becomes high, the refrigerant is R134a and the refrigerating machine oil is synthetic oil.

The length of the refrigerant pipe from the compressor 11 to the heat exchanger 14 on the use side is determined in consideration of the installation of a building and is, for example, about 30 to 50 m one way. Therefore, the oil separator 12 is provided so as not to circulate the oil in the refrigerant pipe, and a pipe line 17 for guiding the cooling water of the engine 1 is wound around the outer periphery of the case of the compressor 11, and this pipe line 17 is provided. Is provided with an on-off valve 18, for example, the compressor 11
For a certain period of time before starting, the on-off valve 18 is opened, a part of the engine cooling water is guided to the pipe line 17, and the cooling water heats the case of the compressor 1 to the compressor 11. Oil spill-out control is performed.

Further, the compressor 11 is provided with an electric motor (not shown) controlled by an inverter, and the electric power from the generator 2 is supplied to the electric motor via the control device 4. The control device 4 includes a temperature sensor 19 provided at the water inlet of the water-refrigerant heat exchanger 7 and the on-off valve 1 described above.
8 and the power control device 3 are connected.

In this cogeneration system,
The user side collects the exhaust heat of the engine 1 and stores it in the hot water storage tank 1
Hot water is stored in 3.

Next, the operation will be described.

The cooling water that has recovered the exhaust heat of the engine 1 reaches the wax type switching valve 9. This wax type switching valve 9
The flow path is switched depending on whether the temperature of the cooling water is 85 ° C. or higher or 85 ° C. or lower, and when the temperature of the cooling water is 85 ° C. or higher, the cooling water passes through the wax type switching valve 9 and the air heat exchanger 6 Then, the air heat exchanger 6 radiates heat, cools it, and returns it to the engine 1.

On the other hand, when the temperature of the cooling water is 85 ° C. or lower,
The cooling water enters the water-to-refrigerant heat exchanger 7 via the wax type switching valve 9.

The temperature of the water entering the water-to-refrigerant heat exchanger 7 is measured by the temperature sensor 19, and if this temperature is below a predetermined temperature, the cooling water does not exchange heat in this water-to-refrigerant heat exchanger 7, It is returned to the engine 1 as it is.

On the other hand, when the temperature of the water entering the water-refrigerant heat exchanger 7 exceeds a predetermined temperature, the compressor 11
Is driven. When driving this, as described above,
The on-off valve 18 is opened for a certain period of time before starting, and a part of the engine cooling water is guided to the pipe line 17. The cooling water heats the case of the compressor 1 and oil to the compressor 11 is supplied. The laying-out control of the person is performed.

When the compressor 11 is driven, the refrigerant circulates in the refrigeration cycle 10. In the process of this circulation, in the water-refrigerant heat exchanger 7, the refrigerant is heated by the cooling water having a temperature close to 85 ° C., so that the evaporation temperature becomes high and becomes high-pressure gas, which is sucked into the compressor 11 and frozen. Cycle 10
Circulate inside.

In this embodiment, since the heat pump is constituted by using the evaporator on the primary side and the condenser on the secondary side, it is possible to raise the temperature even if the cooling water is at a relatively low temperature. If it is 85 ° C., the evaporation temperature can be 70 ° C. or higher, the condensation temperature can be about 100 ° C., and a high temperature can be raised on the use side.

Therefore, it can be used not only for hot water supply but also for drying and sterilization systems and the like, and the applications can be expanded.
In addition to expanding this application, it will be possible to improve the efficiency of hot water storage in the hot water storage tank, reduce the cost of piping work by using copper piping, improve the durability of the piping, and eliminate the need for freeze prevention and other initial costs other than units.

In order to popularize and promote the cogeneration system, it is essential to improve the overall efficiency and the economic efficiency. Therefore, it goes without saying that the efficiency of the engine 1 is improved, and the exhaust heat utilization needs to be expanded by about 70%.

In the present embodiment, the cooling water from which the exhaust heat of the engine is recovered is used to enable a high temperature rise on the user side. Therefore, the range of heat utilization can be widened and the overall efficiency can be improved. Will be possible.

Although the present invention has been described based on the embodiment, it is obvious that the present invention is not limited to this.

[0031]

According to the present invention, since a high temperature can be raised on the side of use, it can be used not only for hot water supply but also for drying and sterilization systems, and the applications can be expanded.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing an embodiment of a cogeneration system according to the present invention.

[Explanation of symbols]

1 engine 2 generator 3 Power control device 4 control device 5 Exhaust gas heat exchanger 9 Wax type switching valve 6 Pneumatic heat exchanger 7 Water-to-refrigerant heat exchanger (evaporator) 10 Refrigeration cycle (heat transfer cycle) 11 compressor 12 Oil separator 13 Hot water storage tank 14 Use side heat exchanger (condenser) 15 Pressure reducing device 16 Accumulator 18 open / close valve 19 Temperature sensor

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Tsukasa Ichikawa             1 Otsuki-cho, Ashikaga City, Tochigi Prefecture Sanyo Electric Air Conditioning             Within the corporation (72) Inventor Kazuo Nomura             1 Otsuki-cho, Ashikaga City, Tochigi Prefecture Sanyo Electric Air Conditioning             Within the corporation (72) Inventor Masashi Takazawa             1 Otsuki-cho, Ashikaga City, Tochigi Prefecture Sanyo Electric Air Conditioning             Within the corporation (72) Inventor Tomio Mogi             1 Otsuki-cho, Ashikaga City, Tochigi Prefecture Sanyo Electric Air Conditioning             Within the corporation (72) Inventor Kuniue Sekigami             1 Otsuki-cho, Ashikaga City, Tochigi Prefecture Sanyo Electric Air Conditioning             Within the corporation

Claims (5)

[Claims] 1. Exhaust heat from an external heat source is guided to a heat source side heat exchanger, the heat source side heat exchanger recovers the waste heat to heat the heat carrier medium, and the heat carrier medium is compressed by a compressor. A cogeneration system comprising a heat transfer cycle in which the heat source side heat exchanger and the pressure reducing device are sequentially introduced and circulated in the heat source side heat exchanger. 2. The coater according to claim 1, wherein an accumulator is provided on a suction side of the compressor, an oil separator is provided on a discharge side of the compressor, and the accumulator, the compressor and the oil separator have a high pressure design structure. Generation system. 3. The exhaust heat is exhaust heat of an engine for driving a generator, the exhaust heat is recovered by engine cooling water, and a part of the cooling water pipe is wound around the compressor. The cogeneration system according to claim 1 or 2. 4. The exhaust heat is exhaust heat of an engine for driving a generator, and control means for supplying electric power of the generator to the compressor is provided. The cogeneration system according to item 1. 5. The cogeneration system according to claim 1, wherein the utilization side heat exchanger is wound around a hot water storage tank.