JP3049670B2 - Sewage heat recovery heat pump - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sewage waste heat recovery heat pump using waste heat of sewage treatment waste water as a heat source.

[0002]

2. Description of the Related Art FIG. 6 shows a schematic configuration diagram of a conventional sewage waste heat recovery heat pump system. The heat pump 10 includes a compressor 12, a first heat exchanger 14 acting as an evaporator, a second heat exchanger 16 acting as a condenser, and an expansion valve 18. The working medium compressed to a high pressure in the compressor 12 is sent to a second heat exchanger 16 acting as a condenser, where it is condensed and liquefied while releasing heat.

[0003] The liquefied working medium is then sent to an expansion valve 18 where the pressure is reduced to the evaporation pressure. Subsequently, the working medium sent to the first heat exchanger 14 acting as an evaporator evaporates while absorbing heat there. The evaporated working medium is sent to the compressor 12, where it is compressed to a high pressure again, and the same cycle is repeated.

The first heat exchanger 1 of the heat pump 10
A water circulation circuit 22 through which water is circulated by a water circulation pump 20 is connected to 4, and the water supplied to the first heat exchanger 14 is cooled by heat absorption. The second heat exchanger 16 is connected to one end of an exhaust heat recovery circuit 26 in which the exhaust heat recovery water is circulated by an exhaust heat recovery pump 24. Is heated by the heat radiation. An exhaust heat recovery heat exchanger 28 is connected to the other end of the exhaust heat recovery circuit 26. The waste heat recovery heat exchanger 28 is filled with sewage treated water pumped by a drainage pump 30. Therefore, heat exchange is performed between the sewage treatment water and the waste heat recovery water.

[0005] Outgoing path 22a and return path 22b of water circulation circuit 22
Are provided with three-way valves 32 and 34, respectively. The exhaust heat recovery circuit 26 also has a forward path 26a and a return path 26b.
Are fitted with three-way valves 36 and 38, respectively. The three-way valve 32 on the outward path of the water circulation circuit 22 is connected to the outward path 26a of the exhaust heat recovery circuit 26 by a bypass 22c, and the three-way valve 34 on the return path 22b is connected to the return path 26d of the exhaust heat recovery circuit 26 by a bypass 22d. ing. Also,
The three-way valve 36 of the outward path 26a of the exhaust heat recovery circuit 26 is connected to the return path 22b of the water circulation circuit 22 by a bypass 26c, and the three-way valve 38 of the return path is connected to the outward path 22a of the water circulation circuit 22.
Are connected by a bypass 26d.

The operation of this conventional sewage waste heat recovery heat pump system in a cooling cycle will be described. As shown in FIG. 7, the three-way valves 32, 34, 36 and 38 are connected straight with their bypass sides closed. ,
The water circulated by the water circulation pump 20 is supplied to the water circulation circuit 2
It enters the first heat exchanger 14 through the second outward path 22a. Then, heat absorption is performed, so that the cooled water is circulated as cold water through the return path 22b of the water circulation circuit 22 and used for cooling.

On the other hand, the water circulated by the exhaust heat recovery pump 24 enters the second heat exchanger 16 via the outward path 26a of the exhaust heat recovery circuit 26, and is heated by the heat of the exchanger.
The heated water enters the exhaust heat recovery heat exchanger 28 via the return path 26b of the exhaust heat recovery circuit 26. Exhaust heat recovery heat exchanger 2
Since the sewage treatment water is injected into 8 by the pump 30, the heated water is cooled by the exhaust heat recovery heat exchanger 28 and enters the exhaust heat recovery pump 24 again.

Next, the heating cycle will be described.
As shown in FIG. 8, the three-way valves 32, 34, 36, and 38 are switched to the bypass side, respectively, and the water supplied by the water circulation pump 20 is supplied to the exhaust heat recovery circuit 26 by the three-way valve 32 in the water circulation outward path. Flows into the bypass 22c of
It enters the outward path 26 a of the exhaust heat recovery circuit 26 and reaches the second heat exchanger 16. The water that has entered the second heat exchanger 16 is heated there by the heat radiation of the heat exchanger.

The heated water enters the return path 26b of the exhaust heat recovery circuit 26, and the three-way valve 38 of the return path is connected to the bypass 26d of the water circulation circuit 22 to the outward path, and is connected to the second heat exchanger 16 side. Is in the closed state, the return path 2 of the water circulation circuit
It flows into the bypass 22d from 2b. This bypass 2
The hot water flowing into 2d is circulated through the three-way valve 34 to the return path 22b of the water circulation circuit 22 and used for heating.

On the other hand, the water that has entered the forward path 26a of the exhaust heat recovery circuit by the exhaust heat recovery pump 24 is switched by the three-way valve 36 to the bypass 30c to the return path 22b of the water circulation circuit. The three-way valve 34 of the return path 22b of the water circulation circuit is switched to the bypass 22d to the return path 26b of the exhaust heat recovery circuit, and the first heat exchanger 14 side is in a closed state. The water that has entered flows backward into the first heat exchanger 14 through the return path 22b of the water circulation circuit. Then, the water is cooled by the endothermic heat of the first heat exchanger 14.

The circulating water cooled in the first heat exchanger 14 reverses the outward path 22a of the water circulation circuit and reaches the three-way valve 34. The three-way valve 34 is bypassed to the outward path 26a of the exhaust heat recovery circuit. Since it is switched to 22c and the first heat exchanger 14 side is in the closed state, the circulating water flows into the bypass 26d from the return path of the exhaust heat recovery circuit. Therefore, since the three-way valve 38 in the return path of the exhaust heat recovery circuit is switched to the exhaust heat recovery heat exchanger 28 side, the circulating water passes through the three-way valve 38 and is recovered by the forward path 26b of the exhaust heat recovery circuit. It flows into the heat exchanger 28.

Since the sewage treatment water is injected into the waste heat recovery heat exchanger 28 by the pump 30, the circulating water is heated by the sewage treatment water in the waste heat recovery heat exchanger 28, and is again returned to the circulation pump 28. Return to

[0013]

However, in the conventional sewage waste heat recovery heat pump system, a waste heat recovery heat exchanger is provided in order to use the sewage treatment waste water as a heat source, and a sewage treatment waste water pump is provided in the heat exchanger. And a waste heat recovery circuit using a waste heat recovery pump between the waste heat recovery heat exchanger and the first heat absorption heat exchanger or the second heat radiation heat exchanger on the heat pump side. Therefore, in addition to the water circulation pump of the water circulation circuit for extracting cold water or hot water from the heat pump, a sewage treatment drainage pump and an exhaust heat recovery pump are required.

Further, since it is necessary to operate four three-way valves to switch between the heating cycle and the cooling cycle, four solenoid valves are required. As a result, the equipment cost is increased, and extra work is required for maintenance and inspection of the equipment. Furthermore, when hot water supply is required in addition to cooling or heating, there is an inconvenience that a separate boiler must be installed.

The present invention has been made to solve the above-mentioned problems of the conventional heat pump system for recovering sewage waste heat, and it is possible to reduce the number of pumps and solenoid valves and to supply hot water as needed. It is an object of the present invention to provide a sewage waste heat recovery heat pump.

[0016]

SUMMARY OF THE INVENTION In order to reduce the number of pumps, the inventor has conceived of exhausting the exhaust heat recovery heat exchanger and directly exchanging heat with sewage treatment wastewater. Furthermore, the present inventors have conceived of using a four-way valve to reduce the number of solenoid valves, and have conducted intensive research on this labor-saving heat pump circuit. As a result, the present invention has been completed.

The heat pump for recovering sewage waste heat according to the present invention has a closed circuit comprising a compressor, a first heat exchanger acting as an evaporator, a second heat exchanger acting as a condenser, and an expansion valve. in the heat pump for circulating the working medium, a heating cycle with 3-way valve and four-way valve circuit in the heat pump circuit having a third heat exchanger comprising direct heat exchange with the sewage effluent a second expansion valve Or hot water
In the cycle, it acts as an evaporator and works as a cooling cycle
, The working medium is circulated by switching between the three-way valve and the four-way valve,
The gist is that the first heat exchanger and the third heat exchanger function as an evaporator or a condenser.

[0018]

In the heating cycle, by switching between the three-way valve and the four-way valve, the first heat exchanger functions as a condenser and the third heat exchanger functions as an evaporator. This first
Water is circulated by the water circulation circuit in the heat exchanger of
The circulating water becomes hot water by the heat radiation of the first heat exchanger and is taken out and used as heating. The third heat exchanger absorbs heat due to the evaporation of the working medium, but directly exchanges heat with the sewage treatment wastewater, so that the sewage waste heat is recovered here.

In the cooling cycle, the three-way valve and the four-way valve
By switching the way valve, the first heat exchanger acts as an evaporator and the third heat exchanger acts as a condenser. Since water is circulating in the first heat exchanger by the water circulation circuit, the circulating water is taken out as heat and absorbed by the first heat exchanger, and is used as cooling. The third heat exchanger radiates heat by solidification of the working medium, but directly exchanges heat with the sewage treatment wastewater, and is cooled here by the sewage treatment water.

In the hot water supply cycle, the three-way valve and the four-way valve
By switching the way valve, the second heat exchanger acts as a condenser and the third heat exchanger acts as an evaporator. Since water is circulated to the second heat exchanger by the hot water supply circuit,
The circulating water becomes hot water by the heat radiation of the second heat exchanger and is taken out. Since the third heat exchanger directly exchanges heat with the sewage treatment wastewater, the sewage waste heat is recovered here.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram of one embodiment of the present invention. Compression side of the compressor 12 of the heat pump 10 is 3-way valve 4
0, is connected to the inlet 42a of the four-way valve 42,
The suction side is connected to the outlet 42c of the four-way valve 42.

One end of the first heat exchanger 14 acting as a condenser or evaporator is connected to the outlet 42b of the four-way valve 42, and the other end is provided with a first check valve 44 for checking the return direction. A first expansion valve 46 having a bypass and a first two-way valve 48
And a second check valve for checking the going direction is connected in sequence, and connected to a second heat exchanger 16 acting as a condenser.
The other end of the second heat exchanger 16 is connected to a three-way valve 40.

The third heat exchanger 60 is for directly exchanging heat with sewage treatment wastewater, and has one end connected to a second two-way valve 52.
Is connected to the outlet 42d of the four-way valve 42 via the. Also, the other end is connected in sequence to a second expansion valve 58 and a third two-way valve 54 having a third check valve 56 for checking the return direction as a bypass. It is connected between the second check valves 50.

The first heat exchanger 14 has a water circulation pump 2
0 is connected to a water circulation circuit 22 that circulates water to take out cold water or hot water, and a second heat exchanger 16 is connected to a hot water supply circuit 62 through which water is supplied by a hot water supply pump 64 to take out hot water. Is directly immersed in sewage treatment wastewater.

The operation of the sewage waste heat recovery heat pump of this embodiment will be described with reference to FIGS. The heating cycle is as shown in FIG. 2, and the three-way valve 40 is
The two side and the four-way valve 42 side are connected, and the four-way valve is
2a and the outlet 42b are connected, and the outlet 42c and the outlet 42d
Are connected. In addition, the first two-way valve 48 and the second
The one-way valve 52 and the third two-way valve 54 are open.

The working medium compressed to a high pressure by the compressor 12 is sent to the first heat exchanger 14 via a three-way valve 40 and a four-way valve 42. Since the first heat exchanger 14 acts as a condenser, the working medium sent to the first heat exchanger 14 condenses and liquefies while releasing heat there. Since water is circulated through the first heat exchanger 14 by the water circulation circuit 22, the circulating water becomes hot water by the heat radiation of the first heat exchanger 14 and is taken out and used as heating.

The liquefied working medium exiting the first heat exchanger 14 reaches a first expansion valve 46 having the first check valve 44 as a bypass, but the first check valve 44 returns in the return direction. , The working medium flows toward the first check valve 44 and passes through the first two-way valve 48. The working medium that has passed through the first two-way valve 48 is blocked in the going direction by the second check valve 50, flows through the third two-way valve 54, and bypasses the third check valve 56. To the second expansion valve 58.

The third check valve 56 checks the working medium in the return direction, that is, the direction returning from the third two-way valve, so that the working medium flows into the second expansion valve 58. In the second expansion valve 58, the liquefied working medium is reduced to the evaporation pressure. Subsequently, the working medium sent to the third heat exchanger 60 acting as an evaporator evaporates while absorbing heat there. Since the third heat exchanger 60 directly exchanges heat with the sewage treatment wastewater, it is cooled by the sewage treatment wastewater.

The working medium evaporated and vaporized in the third heat exchanger 60 passes through the second two-way valve 52 and exits 42 d of the four-way valve 42.
to go into. However, since the outlets 42c and 42d of the four-way valve communicate with each other, the working medium returns from the outlet 42b to the suction side of the compressor 12. The working medium sucked into the compressor 12 repeats the same cycle.

Next, the cooling cycle of FIG. 3 will be described. The three-way valve 40 is connected between the compressor 12 and the four-way valve 42, and the four-way valve is connected between the inlet 42a and the outlet 42d, and the outlets 42b and 42c. Are connected. Also, the first
Two-way valve 48, second two-way valve 52 and third two-way valve 5
Reference numeral 4 denotes an open state.

The working medium compressed to a high pressure in the compressor 12 reaches the inlet 42 a of the four-way valve 42 via the three-way valve 40.
Since the inlet 42a of the four-way valve is in communication with the outlet 42d, the working medium flows through the third two-way valve 54 and flows into the third heat exchanger 60. Here, since the third heat exchanger 60 acts as a condenser, the working medium condenses and liquefies while releasing heat there. Since the third heat exchanger 60 directly exchanges heat with the sewage treatment wastewater, the sensible heat of the sewage treatment wastewater is used here.

The working medium condensed and liquefied in the third heat exchanger 60 reaches the second expansion valve 58 having the third check valve 56 as a bypass, but the third check valve 56 moves in the forward direction. Therefore, the working medium passes through the third check valve 56 and passes through the third two-way valve 54 to the first two-way valve 48 and the second check valve 56.
To the branch point between the check valves 50.

Then, since the second check valve 50 operates, the working medium flows to the first two-way valve 48 side to reach the first expansion valve 46 having the first check valve 44 as a bypass. Since the first check valve 44 checks the return direction, the working medium passes through the first expansion valve 46. In the first expansion valve 46, the liquefied working medium is reduced to the evaporation pressure.

Subsequently, the working medium sent to the first heat exchanger 14, which acts as an evaporator, evaporates while absorbing heat there. Since water is circulated in the first heat exchanger 14 by the water circulation circuit 22, the circulating water is
The heat is absorbed by the heat exchanger 14 and becomes cold water to be taken out and used as cooling.

The working medium evaporated and vaporized in the first heat exchanger 14 enters the outlet 42 b of the four-way valve 42. However, since the outlets 42b and 42c of the four-way valve communicate with each other, the working medium returns from the outlet 42c to the suction side of the compressor 12. Compressor 1
The working medium sucked in 2 repeats the same cycle.

Next, the hot water supply cycle will be described with reference to FIG. The three-way valve 40 is connected between the compressor 12 and the second heat exchanger 16, and the four-way valve is connected to the outlets 42 c and 42
d is connected. In addition, the first two-way valve 48 is closed, and the second two-way valve 52 and the third two-way valve 54 are open.

The working medium compressed to a high pressure by the compressor 12 flows into the second heat exchanger 16 via the three-way valve 40.
Here, since the second heat exchanger 16 acts as a condenser, the working medium condenses and liquefies while releasing heat there. A hot water supply circuit 62 is connected to the first heat exchanger 16, and the supplied water circulates as hot water.

The liquefied working medium that has exited the second heat exchanger 16 reaches the second check valve 50 but passes through the second check valve 50 because the second check valve 50 does not work in the going direction. The working medium that has passed through the second check valve 50 flows through the third two-way valve 54 because the first two-way valve 48 is in a closed state, and bypasses the third check valve 56. To the second expansion valve 58.

The third check valve 56 checks the working medium in the return direction, that is, the direction returning from the third two-way valve, so that the working medium flows into the second expansion valve 58. In the second expansion valve 58, the liquefied working medium is reduced to the evaporation pressure. Subsequently, the working medium sent to the third heat exchanger 60 acting as an evaporator evaporates while absorbing heat there. Since the third heat exchanger 60 directly exchanges heat with sewage treatment wastewater, sewage waste heat is recovered here.

The working medium vaporized and vaporized in the third heat exchanger 60 passes through the second two-way valve 52 to the outlet 42 c of the four-way valve 42.
to go into. However, since the outlets 42c and 42b of the four-way valve communicate with each other, the working medium returns from the outlet 42b to the suction side of the compressor 12. The working medium sucked into the compressor 12 repeats the same cycle.

As shown in FIG. 5, the three-way valve 40 connects the compressor 12 side to the second heat exchanger 16 side, and the four-way valve connects the outlets 42b and 42c, and the first two-way valve When the two-way valve 52 is opened and the second two-way valve 52 and the third two-way valve 54 are closed, a cooling and exhaust heat and hot water supply cycle is performed, and the first heat exchanger 14 acts as an evaporator to absorb heat. We, the second
The heat exchanger 16 functions as a condenser and radiates heat, so that cold water is obtained in the water circulation circuit 22 and hot water is obtained in the hot water supply circuit 62.

[0042]

As described above, the heat pump for recovering sewage waste heat according to the present invention has the first function as a compressor and an evaporator.
A heat pump for circulating a working medium through a closed circuit comprising a heat exchanger, a second heat exchanger acting as a condenser and an expansion valve, comprising an expansion valve and directly exchanging heat with sewage treatment wastewater. Circuit having a heat exchanger of the type described above in a heating cycle or a hot water supply cycle using a three-way valve and a four-way valve
Works as an evaporator in the cooling cycle.
Connected to act as a condenser, circulating the working medium by switching between a three-way valve and a four-way valve to cause the first heat exchanger and the third heat exchanger to act as an evaporator or a condenser In this case, cold or hot water for heating or cooling is obtained by heat absorption or heat dissipation of the first heat exchanger, and sewage treatment wastewater can be used as a heat source by the third heat exchanger. Therefore, an extra pump is not required for recovering exhaust heat of the sewage treatment wastewater, and switching between cooling and heating can be performed with a small number of solenoid valves.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an embodiment of the present invention.

FIG. 2 is a schematic configuration diagram illustrating a heating cycle in the embodiment of FIG.

FIG. 3 is a schematic configuration diagram illustrating a cooling cycle in the embodiment of FIG.

FIG. 4 is a schematic configuration diagram illustrating a hot water supply cycle in the embodiment of FIG. 1;

FIG. 5 is a schematic configuration diagram illustrating a cooling hot water supply cycle in the embodiment of FIG. 1;

FIG. 6 is a schematic configuration diagram of a conventional sewage waste heat recovery heat pump system.

FIG. 7 is a schematic configuration diagram illustrating a heating cycle of a conventional sewage waste heat recovery heat pump system.

FIG. 8 is a schematic configuration diagram illustrating a cooling cycle of a conventional sewage waste heat recovery heat pump system.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 Heat pump 12 Compressor 14 1st heat exchanger 16 2nd heat exchanger 18 Expansion valve 20 Water circulation pump 22 Water circulation circuit 24 Exhaust heat recovery pump 26 Exhaust heat recovery circuit 28 Exhaust heat recovery heat exchanger 30 Drainage pump 32 , 34 Three-way valve for water circulation circuit 36, 38 Three-way valve for exhaust heat recovery circuit 40 Three-way valve for heat pump circuit 42 Four-way valve 44 First check valve 46 First expansion valve 48 First two-way valve Reference Signs List 50 second check valve 52 second two-way valve 54 third two-way valve 56 third check valve 58 second expansion valve 60 third heat exchanger 62 hot water supply circuit 64 hot water supply pump

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Yoshitomi Shiba 1-643 Noda, Nakagawa-ku, Nagoya City, Aichi Prefecture General Heat Pump Industry Co., Ltd. (56) References JP-A-60-238661 (JP, A) 59-133972 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) F25B 29/00 F25B 27/02

Claims (1)

(57) [Claims] 1. A heat pump for circulating a working medium through a closed circuit including a compressor, a first heat exchanger acting as an evaporator, a second heat exchanger acting as a condenser, and an expansion valve. A circuit having a third heat exchanger equipped with a second expansion valve and directly exchanging heat with sewage treatment wastewater,
Heating cycle or hot water supply using one-way and four-way valves
In the vehicle, it acts as an evaporator and works in the cooling cycle.
The three-way valve and the four-way valve are switched to circulate a working medium, and the first heat exchanger and the third heat exchanger are connected to an evaporator or a condenser. A sewage heat recovery heat pump characterized by functioning as a heat pump.