JPH0854156A - Cooling and heating device utilizing exhaust heat of engine and operating method thereof - Google Patents

Abstract

PURPOSE:To provide a cooling and heating device utilizing the exhaust heat of an engine and the operating method thereof, which is capable of operating efficiently by a simple and compact device. CONSTITUTION:A cooling and heating device, utilizing the exhaust heat of an engine 5, is provided with an exhaust gas heat exchanger 26, recovering the exhaust heat of a generating engine 24 as hot-water or steam, an absorption type water cooling and heating machine as well as a heat exchanger for heating, employing the recovered exhaust heat as heat sources, and a cold water system 15 for cooling or a hot-water system 15 for heating, which is connected to the absorption type water cooling and heating machine and the heat exchanger for heating. A compression type refrigerating machine 23, utilizing an electric power generated by the generating engine 24, is connected to the cold water system 15 for cooling while an electric heater 22, utilizing an electric power generated by the generating engine 24, is connected to the hot-water system 15 for heating while the compression type refrigerating machine 23 or the electric heater 22 is driven by the electric power, generated by the generating engine, when an electric load is less than a rated load and cooling and heating load is higher than the cooling and heating output, outputted by the exhaust heat of the operating generating engine during cooling and heating operation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heating and cooling system, and more particularly to a cooling and heating system that uses both the exhaust heat of a power generating engine and generated electricity.

[0002]

2. Description of the Related Art In an absorption refrigerator driven by exhaust heat from an engine, if the electric load is small, the amount of exhaust heat is small and the refrigerating output (capacity) is small. In this state, if the cooling load is large, operating the compression refrigerator by consuming electricity will not only back up the cooling load but also increase the exhaust heat (hot water heat amount) due to the increase in the power generation amount, The fact that the output also increases is described in Japanese Patent Publication No. 58-15705. However, this publication describes only the cooling method as the heat recovery method in the power generation equipment.

In the case of heating, it is conceivable to back up the heating with a heat pump, but in this case, what is used for the low temperature side heat source becomes a problem. If there are rooms to be cooled, such as in building air conditioning, use these as the heat source,
Generally, air is often used as a heat source. This method is more efficient than the case of using an electric heater, but the apparatus is complicated and the apparatus is large. The air heat exchanger may be as large as a cooling tower for an absorption refrigerator. Further, depending on the outside air temperature condition, frost may be formed on the air heat exchanger, which requires defrosting operation and complicates the apparatus.

[0004]

SUMMARY OF THE INVENTION In view of the above points, the present invention provides a cooling and heating device that utilizes engine exhaust heat and can be operated efficiently with a simple and compact device for heating and a method of operating the same. Is an issue.

[0005]

In order to solve the above problems, in the present invention, an exhaust gas heat exchanger for recovering exhaust heat of a power generation engine as hot water or steam, and an absorption cold temperature using the recovered exhaust heat as a heat source. A cooling and heating device that has a water machine and a heating heat exchanger, and that uses engine exhaust heat having a cooling cold water system or a heating hot water system that is connected to the absorption chiller-heater and the heating heat exchanger, wherein: In the cold water system for use, a compression type hot and cold water machine that uses electricity generated by the power generation engine is connected, and in the hot water system for heating, an electric heater that uses electricity generated by the power generation engine is connected. is there.

In the above cooling and heating apparatus, the absorption chiller-heater and the compression refrigerator are connected by a cooling tower and a cooling water pipe, and cooling water returns from the cooling tower to the absorption refrigerator and then the compression refrigerator to the cooling tower. It is better to connect as. In the operating method of the engine exhaust heat utilization air conditioner of the present invention described above, when the electric load is less than the rating and the air conditioner load exceeds the air conditioner output by the engine exhaust heat for power generation during operation,
The compression refrigerator or the electric heater is driven by electricity generated by the power generation engine.

As described above, in the present invention, the exhaust heat of the power generation engine is recovered as hot water (or steam, or hot water and steam), and during the cooling operation, it is cooled by the absorption refrigerator using the exhaust heat as a heat source. In the cooling and heating system using engine exhaust heat, which produces cold water for heating and also produces hot water for heating by exchanging heat with the exhaust heat (or via an absorption refrigerator) during heating operation, electricity generated by a power generation engine Is provided in the cooling cold water system, and an electric heater that uses electricity generated by the power generation engine is provided in the heating hot water system. Further, the heat exchanger for heating can also serve as an absorption chiller-heater, and in this case, it is not necessary to separately provide a heat exchanger for heating.

[0008]

As described above, in the present invention, when the heating load exceeds the output due to the exhaust heat, the backup system is simplified by using the heater without using the compression refrigerator, that is, without operating as a heat pump. ing. If the electric load is small, the amount of exhaust heat is small, and if the heating load is large in this state, using the heater by consuming electricity serves as a backup for the heating load, and there is also an increase in the exhaust heat due to the increase in the amount of power generation. Will increase.

As described above, in the present invention, the efficiency based on the fuel is higher than that in the case where the electric heater alone is used, because the exhaust heat is used in the fuel-based efficiency. Further, in the present invention, the cooling water can be commonly used for the absorption type and the compression type. Generally, the temperature of exhaust heat is not so high that it is preferable to supply the cooling water as low as possible in the absorption type, and it is preferable that the cooling water from the cooling tower is first made to flow to the compression type in the absorption refrigerator.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below with reference to the drawings, but the present invention is not limited to these embodiments. Embodiment 1 FIG. 1 and FIG. 2 show an overall configuration diagram of an engine exhaust heat utilizing air conditioner / heater of the present invention. FIG. 1 shows the flow rate of hot water to the absorption chiller / heater for the capacity control of the absorption chiller / heater. FIG. 2 is an example in which the control 30 is performed, and FIG. 2 shows the opening of the refrigerant vapor valve 7 between the regenerator / condenser can body and the absorber / evaporator can body in the absorption chiller / heater for the capacity control of the absorption chiller / heater. In this example, the degree control (refrigerant vapor amount control) is performed.

1 and 2, G is a regenerator, A is an absorber, E is an evaporator, C is a condenser, H is a solution heat exchanger,
Pipes 1 to 4 are solution passages, pipes 5 and 6 are refrigerant passages, 7 is a refrigerant valve, 8 is a refrigerant gas bypass passage, 9 is a cooling tower, 10 is a cooling water pump, 11 is a solution pump, 12 is a refrigerant pump, and a pipe. Reference numerals 13 and 14 are heat source passages, and pipes 16 and 17 are cooling water passages, which form an absorption chiller-heater. In addition, a compression refrigerator 23 including a compressor 18, a cooler 19 and an evaporator 20 and a heating water heater including a heat exchanger 21 and a heater 22 are provided adjacent to the absorption chiller / heater.

Further, in order to generate electricity, an exhaust gas heat exchanger 26 is provided which includes an engine 24 and a generator 25 and recovers the heat quantity of the exhaust gas of the engine 24. Then, hot water serving as a heat source of the regenerator G is heated by the exhaust gas heat exchanger 26 of the heat source passage 14 and used as a heat source by the regenerator G, and cooled hot water is used for cooling the engine 24 from the passage 13. After that, it is heated in the exhaust gas heat exchanger 26 and circulated. In such a device, in the cooling cycle, when the cooling load can be covered only by the engine exhaust gas, the regenerator G is operated by hot water recovered from the exhaust gas.

The dilute solution that has absorbed the refrigerant flows from absorber A to tube 1.
Through the pump 11 to the heated side of the heat exchanger H, and the diluted solution heated by the heat exchange is introduced into the regenerator G through the pipe 2. In the regenerator G, the jacket jacket water of the engine from the pipe 14 is heated by the heat source of the exhaust gas,
The absorbed refrigerant vapor is evaporated and concentrated. The concentrated concentrated solution passes from the pipe 3 through the heating side of the heat exchanger H, is introduced from the pipe 4 to the absorber A, absorbs the refrigerant again, and becomes a dilute solution, which is circulated from the pipe 1.

On the other hand, the refrigerant vapor generated in the generator G reaches the condenser C, is cooled and condensed by the cooling water 16 in the condenser C, and is introduced into the evaporator E from the pipe 5. In the evaporator E, the refrigerant takes heat from the cold water, exhibits a freezing effect, and evaporates. The vaporized refrigerant vapor is absorbed by the solution in the absorber A. The absorbed heat at the time of absorption is cooled by the cooling water from the pipe 16 flowing through the absorber. In the heating cycle, the absorption cooling water heater closes the cooling water flowing through the absorber A and the condenser C, and the refrigerant vapor from the regenerator G is directly evaporated by the evaporator E.
And heating the warm water 15 for heating by the heat of condensation.

Then, the backup by electric power is applied to the power generation engine 2 for the cooling load or the heating load.
This is the case where the exhaust heat of 4 cannot cover the cost. However, backup cannot be applied until the electrical load reaches the rated point and above the rated point. During cooling, for example, if the cold water temperature does not drop to a predetermined temperature, the compression type refrigerator 23 is used as a backup because the load is large. At this time, the power generation amount is monitored, and the compression type is operated so as not to exceed the rated power. That is, the capacity of the compression refrigerator is controlled so that the generated current is kept below the rated value. For example, when the capacity of the compression refrigerator is controlled by the rotation speed, the rotation speed is limited so that the current does not exceed.

During heating, if the temperature of the hot water does not rise to a predetermined temperature, for example, it is determined that the load is large, and the heater 22 backs up. At this time, the power generation amount is monitored and the heater input is limited so as not to exceed the rated power. The timing of backup is shown in FIG. 3 for the case of cooling.
In this case, it is expressed as performing proportional control. In order to preferentially use the exhaust heat absorption chiller / heater, the control target temperature of the chilled water outlet of the exhaust heat chiller / heater is set lower than the chilled water outlet target temperature of the compression chiller / heater. The target chilled water outlet temperature for controlling the exhaust heat absorption chiller / heater is set to T (for example, 7 ° C.). On the other hand, the target cold water outlet temperature of the compression type is set to T + α (for example, 9 ° C.), the starting temperature of the compression type is T + α + β (for example, 10 ° C.), and the stop temperature is T + α−β (for example, 8 ° C.).

The timing of backup is shown in FIG. 4 for heating. In order to preferentially use the exhaust heat absorption chiller / heater, the control target temperature of the hot water outlet of the exhaust heat chiller / heater is set higher than the hot water outlet target temperature of the heater.
The target hot water outlet temperature for controlling the exhaust heat absorption chiller / heater is set to T (for example, 42 ° C.). On the other hand, the target hot water outlet temperature of the heater is set to T-α (for example, 40 ° C).

The cooling / heating backup is as described above, but in the case of excessive exhaust heat, it is performed as follows. 1 and 2, when the amount of exhaust heat used in the absorption refrigerator decreases, the temperature of hot water in the engine system rises, the fan 28 for air cooling starts, and the flow rate of hot water to the radiator 29 is controlled to radiate heat. are doing. For example, when the hot water temperature of the engine system rises, heat can be radiated to the absorption refrigerator cooling tower 9 without using the air cooling fan.

[0019]

According to the present invention, a backup system in the case where the exhaust heat alone cannot cope with the cooling and heating loads can be performed with a simple and compact device, and the exhaust heat of the engine and the electric power generated by the engine can be effectively used. It can be used for efficient air conditioning operation.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram showing an example of an engine exhaust heat utilizing cooling / heating apparatus of the present invention.

FIG. 2 is an overall configuration diagram showing another example of an engine exhaust heat utilizing cooling / heating apparatus of the present invention.

FIG. 3 is a graph showing a relationship between target set values in a cooling operation.

FIG. 4 is a graph showing a relationship between target set values in the heating operation.

[Explanation of symbols]

G: regenerator, A: absorber, C: condenser, E: evaporator,
H: solution heat exchanger, 1-4: solution passage, 5, 6: refrigerant passage, 7: refrigerant valve, 8: refrigerant vapor passage, 9: cooling tower, 1
0: cooling water pump, 11: solution pump, 12: refrigerant pump, 13, 14: heat source passage, 15: cold / hot water passage, 16,
17: cooling water passage, 18: compressor, 19: cooler, 2
0: evaporator, 21: heat exchanger, 22: heater, 23:
Compression refrigerator, 24: engine, 25: generator, 26:
Exhaust gas heat exchanger, 27: switching valve, 28: air cooling fan,
29: radiator, 30: control valve, 31: exhaust gas,

Claims (3)

[Claims] 1. An exhaust gas heat exchanger that recovers exhaust heat of a power generation engine as hot water or steam, an absorption chiller-heater that uses the recovered exhaust heat as a heat source, and a heating heat exchanger,
In a cooling and heating apparatus that uses engine exhaust heat having a cooling chilled water system or a heating warm water system connected to the absorption chiller-heater and a heating heat exchanger, the cooling chilled water system uses electricity generated by a power generation engine A heating / cooling system using engine exhaust heat, characterized in that an electric heater that uses electricity generated by a power generation engine is connected in the heating hot water system. 2. The absorption chiller-heater and the compression refrigerator are connected by a cooling tower and a cooling water pipe so that the cooling water returns from the cooling tower to the absorption refrigerator, then the compression refrigerator, and then to the cooling tower. The cooling and heating apparatus for exhaust heat from engine according to claim 1, wherein the cooling and heating apparatus is connected. 3. The method for operating an engine exhaust heat utilizing cooling / heating apparatus according to claim 1 or 2, wherein the electric load is less than the rating and the cooling / heating load exceeds the cooling / heating output by the engine exhaust heat for generation during operation. A method for operating a cooling and heating system using engine exhaust heat, characterized in that a compression refrigerator or an electric heater is driven by electricity generated by a power generation engine.