Waste heat utilization system

Abstract

To provide a waste heat utilization system which can perform a flexible operation according to a change of a situation, and can effectively collect heat from a heat source hot water.SOLUTION: A waste heat utilization system 10A has a waste heat use device 12A for outputting an output hot fluid W2A by raising a temperature of input water W1A, and a waste heat use device 12B for outputting an output cold fluid W2B by cooling the input water W1B. A path in which heat source hot water Wh flows can be switched by a control unit to a first hot water path R1 in which hot water is supplied from a hot water supply port 14A of the first waste heat use device and discharged from a hot water discharge port 16A, and the hot water is supplied from a hot water supply port 14B and discharged from a hot water discharge port 16B, and a second hot water path R2 in which the hot water is supplied from the hot water supply port 14B and discharged from the hot water discharge port 16B, and the hot water is supplied from the hot water supply port 14A and discharged from the hot water discharge port 16A.SELECTED DRAWING: Figure 3

Claims

1. A waste heat utilization system comprising: a first waste heat utilization device that utilizes the thermal energy of hot water discharged from a heat source by exchanging heat with a refrigerant between a first hot water supply port and a first hot water discharge port, thereby raising the temperature of a first input water and outputting a hot fluid; and a second waste heat utilization device that utilizes the thermal energy of the hot water discharged from the heat source by exchanging heat with a refrigerant between a second hot water supply port and a second hot water discharge port, thereby cooling a second input water and outputting a cold fluid; The control unit determines that the path through which the hot water from the heat source flows is: A first hot water path supplied from the first hot water supply port of the first waste heat utilization device and discharged from the first hot water discharge port of the first waste heat utilization device, and further supplied from the second hot water supply port of the second waste heat utilization device and discharged from the second hot water discharge port of the second waste heat utilization device, A second hot water path is supplied from the second hot water supply port and discharged from the second hot water discharge port, and further supplied from the first hot water supply port and discharged from the first hot water discharge port, It is configured to be switchable. A waste heat utilization system characterized by the following:

2. A first hot water channel through which the heat source hot water is introduced to the first hot water supply port via a first valve, A second hot water channel through which the heat source hot water is introduced to the second hot water supply port via a second valve, A first connecting passage connects the first hot water outlet to the second hot water supply outlet via a third valve, A second connecting passage connects the second hot water outlet to the first hot water supply outlet via a fourth valve, A first discharge passage connects the first hot water outlet to the drainage system via a fifth valve, A second discharge passage connects the second hot water outlet to the drainage system via a sixth valve, The waste heat utilization system according to claim 1, characterized by having the following features.

3. The second waste heat utilization device is supplied with cooling water used to cool the second input water. The control unit sets the path to the first hot water path when the temperature of the cooling water is below the threshold temperature. The waste heat utilization system according to claim 1 or 2, characterized by the above.

4. The aforementioned path is further configured to be switchable to a third hot water path in which the heat source hot water is supplied in parallel to the first hot water supply port and the second hot water supply port, and discharged in parallel from the first hot water discharge port and the second hot water discharge port. The waste heat utilization system according to feature 3.

5. The control unit determines the path to be the second hot water path when the temperature of the cooling water is higher than the threshold temperature and the temperature of the hot water discharged from the second hot water outlet is higher than the lower limit temperature of the first waste heat utilization device, and the third hot water path when it is below the lower limit temperature. The waste heat utilization system according to feature 4.

6. A first heat exchanger provided in the first connection path, A first heat exchanger switching circuit is provided in the output path of the output hot fluid and switches whether to pass part or all of the output hot fluid through the first heat exchanger or to output all of it directly. The waste heat utilization system according to claim 2, characterized by having the following features.

7. The control unit is configured to detect the amount of output hot fluid used in the hot fluid utilization device to which the output hot fluid is supplied, and when the amount used is below a reference value and the temperature of the heat source hot water at the second hot water supply port is below the lower limit of the operating temperature of the second waste heat utilization device, the first heat exchanger switching circuit causes at least a portion of the output hot fluid to pass through the first heat exchanger. The waste heat utilization system according to feature 6.

8. The second waste heat utilization device is supplied with cooling water used to cool the second input water. A second heat exchanger provided in the first connection path, A second heat exchanger switching circuit that can be switched to distribute a portion of the cooling water to the second heat exchanger, The waste heat utilization system according to claim 2, characterized by having the following features.

9. The control unit, when the temperature of the heat source hot water at the second hot water supply port exceeds the upper limit of the operating temperature of the second waste heat utilization device, causes the second heat exchanger switching circuit to distribute a portion of the cooling water to the second heat exchanger. The waste heat utilization system according to feature 8.

10. A third heat exchanger is provided in the drainage system, A third heat exchanger switching circuit that causes the first input water to pass through the third heat exchanger or to be directly input to the first waste heat utilization device, The waste heat utilization system according to claim 2, characterized by having the following features.

11. The control unit, when the temperature of the first input water is less than or equal to the temperature of the wastewater in the drainage system, directs the first input water through the third heat exchanger switching circuit. The waste heat utilization system according to feature 10.

12. A return path for returning the first heat-utilized fluid after the output hot fluid has been used for heat utilization in the hot fluid utilization device, A first return path switching circuit that switches the first heat-utilized fluid in the return path to be input to the first waste heat utilization device as first input water, or to be merged with the second hot water supply port, The waste heat utilization system according to claim 2, characterized by having the following features.

13. The control unit, when the temperature of the heat source hot water at the second hot water supply port is below the lower limit of the operating temperature of the second waste heat utilization device, and the temperature of the first heat-utilized fluid exceeds the lower limit of the operating temperature of the second waste heat utilization device, uses the first return path switching circuit to merge the first heat-utilized fluid into the second hot water supply port. The waste heat utilization system according to feature 12.

14. A fourth heat exchanger provided in the first connection path, A return path for returning the first heat-utilized fluid after the output hot fluid has been used for heat utilization in the hot fluid utilization device, A second return path switching circuit that switches the first heat-utilized fluid in the return path to either pass through the fourth heat exchanger or directly input to the first waste heat utilization device as the first input water, The waste heat utilization system according to claim 2, characterized by having the following features.

15. The control unit, when the temperature of the heat source hot water at the second hot water supply port is below the lower limit of the operating temperature of the second waste heat utilization device, and the temperature of the first heat-utilized fluid exceeds the lower limit of the operating temperature of the second waste heat utilization device, causes the first heat-utilized fluid to pass through the fourth heat exchanger via the second return path switching circuit. The waste heat utilization system according to feature 14.

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