JPS6248785B2 - - Google Patents

Description

[Detailed description of the invention]

[Field of Application of the Invention] The present invention relates to an absorption heat pump, and more particularly to an absorption heat pump suitable for saving energy by facilitating switching between cooling and heating. [Background of the Invention] Absorption heat pumps are generally used as air conditioners for buildings and the like because they consume less electricity and are quiet in operation. Conventionally, most of this type of absorption heat pump uses a water-lithium bromide solution, and this cycle is as shown in FIG.
That is, a regenerator 2 is provided which separates a dilute solution into a concentrated solution and refrigerant vapor using a burner 1.
A condenser 3 is connected to the regenerator 2 to condense the separated refrigerant vapor into liquid refrigerant. The liquid refrigerant obtained by the condenser 3 is sent to the evaporator 5 via the pressure reducing valve 4, where it takes away the latent heat of vaporization and performs a cooling effect. An absorber 6 is connected to the evaporator 5, and the absorber 6 absorbs the refrigerant vapor in the evaporator 5 and supplies a dilute solution obtained under pressure to the regenerator 2 using a pump 7. The concentrated solution separated by the regenerator 2 is introduced, and the refrigerant vapor from the evaporator 5 is absorbed at a high capacity. Between the absorber 6 and the regenerator 2, there is heat exchange between the high temperature concentrated solution separated by the regenerator 2 and the low temperature dilute solution fed by the absorber 6, in order to achieve thermal economy. A solution heat exchanger 8 is provided. here,
A cooling water circuit 9 is connected to each of the condenser 3 and absorber 6 in order to condense the refrigerant vapor, and as shown in the figure, the cooling water is passed through the absorber 6 and separated by the regenerator 2. Heat is removed from the concentrated solution that passes through the solution heat exchanger 8, and then from the high temperature separated refrigerant vapor that passes through the condenser 3. In the case of air conditioning, the hot water obtained by absorbing heat is led to a cooling tower or the like. Also, in the case of heating, this hot water is used as is. In this way, thermal efficiency can be improved. On the other hand, from the viewpoint that the above-mentioned absorption heat pump using a water-lithium bromide solution cannot achieve a low temperature below 0°C, a structure using an ammonia-water solution or a fluorocarbon-organic ether solution has been proposed. Things are also known. This is because the solution used is compared to the water-lithium bromide solution mentioned above.
The boiling points of the refrigerant and absorbent are close (about 200°C boiling point difference, 500°C for water and lithium bromide), so special consideration is required. That is, as shown in FIG. 2, in the regenerator 2,
In order to increase the purity of the refrigerant vapor to be separated, a rectifier 10 and a dephlegmator 11 are provided above the rectifier 10, through which the dilute solution fed under pressure from the absorber 6 flows. Although such an absorption heat pump has the disadvantage of requiring a rectifier 10 and a partial condenser 11, on the other hand, the viscosity of the solution is low (1 cp or less, 20 cp for water-lithium bromide), and
Research and development is being carried out on this technology because it has many advantages, such as not having to worry about crystallization and being able to operate at sub-zero temperatures. However, in absorption heat pumps using any solution, the absorber 6 used in these heat pumps is of shell and tube type, liquid can type, multi-tube type, etc., so it can only function as an absorber. Nakatsuta. For this reason,
When performing cooling and heating operations, there is a drawback that separate equipment is required for each cooling cycle and heating cycle. [Object of the Invention] The present invention focuses on these conventional drawbacks, and aims to provide an absorption heat pump that can be used for both cooling and heating operations by making the equipment more compact and allowing the equipment to be shared. . [Summary of the Invention] In order to achieve the above object, the absorption heat pump according to the present invention is capable of switching between a refrigerant circuit and a solution circuit, and uses a double pipe in the heat exchanger to which the heating and cooling load circuit is connected. The structure is such that equipment can be shared. With this configuration, the equipment can be shared, so the equipment itself can be made smaller even if it is used for both cooling and heating operations. [Embodiments of the Invention] Hereinafter, embodiments of the present invention will be described based on the drawings. FIG. 3 is a system diagram showing an embodiment of the absorption heat pump according to the present invention. The reference numeral 31 in the figure is a burner, and the burner 31 is designed to heat the regenerator 32. This regenerator 32 heats the dilute solution 100 and generates a high-pressure concentrated solution 20.
It is designed so that it can be separated into 0H and high temperature steam 300. This concentrated solution 200H is transferred to the solution heat exchanger 3
At step 3, heat is exchanged with the dilute solution 100, and the first pressure reducing valve 35 converts the solution into a low-pressure concentrated solution 200 L. This concentrated solution 200H
and 200L, pipes 36H and 36L constitute a part of the solution circuit. Further, numeral 37 is a first heat exchanger, 38 is a heat exchanger, 39 is a heating and cooling load heat exchanger, 40 is a subcooler, 41 is a solution circulation pump that boosts the pressure of the low-pressure dilute solution and returns it to the regenerator 32;
42, 43, 44 and 45 are the first check valve and the second check valve.
Check valves, third check valve and fourth check valve, 46 and 47 are second pressure reducing valve and third pressure reducing valve, 48, 4
9, 50 and 51 are a first three-way valve, a second three-way valve,
The third three-way valve and the fourth three-way valve 52, 53, and 54 are a first on-off valve, a second on-off valve, and a third on-off valve. These valves are for switching between the solution circuit and the refrigerant circuit. Thus, the piping line 36 is connected to the first check valve 42 , the second on-off valve 53 , and the third three-way valve 50 . One end of the first heat exchanger 37 is connected to the third three-way valve 50, and the other end of the first heat exchanger 37 is connected to the absorption port side of the pump 41 via the first three-way valve 48, and is supercooled. It is connected to one end of the coil of the device 40. The other end of the coil of the supercooler 40 is connected to a heating and cooling load heat exchanger 39. This supercooler 40 has one end connected to one end of the second exchanger 38 and a third three-way valve 50 via a third check valve 44 and a third pressure reducing valve 47 that are connected in parallel. The other end of the second exchanger 38 is connected to the second
The three-way valve 49 is connected to the rectifier 34 and the fourth three-way valve 51 via the fourth check valve, and the supercooler 40
is connected to one end of the coil. One end of the coil of this supercooler 40 is connected to the piping path 36 via a first on-off valve 52 and a first check valve 42 . The second on-off valve 53 is connected to the fourth three-way valve 51 and one end of the heating and cooling load circuit heat exchanger 39. The other end of this heating and cooling load circuit heat exchanger 39 is connected to the suction of the pump 41 via a third on-off valve 54. The heat exchanger 39 has a double pipe 55 inside it.
The load circuit 56 is connected to the outer pipe of this double pipe 55 so that the fluid for the cooling/heating load circuit 56 flows, and one end of the inner pipe of the pipe 55 is connected to the fourth three-way valve 51. The other end of the inner pipe of the pipe 55 is connected to the other end of the supercooler 40 via a second check valve 43 and a second pressure reducing valve 46 connected in parallel. The load circuit 56 is provided with an indoor unit 57 . The operation of the absorption heat pump configured in this way will be explained. FIG. 4 is a cycle diagram showing the case where the absorption heat pump is used for heating operation. Valves 44, 48, 49, 51, 5 shown in FIG.
2, 53, and 54, the valves filled in black indicate that they are closed, and the valves that are not filled in black indicate that they are open. The dilute solution 100 in the regenerator 32 heated by the burner 31 is converted into a high-pressure concentrated solution 200H in the regenerator 32.
and vapor refrigerant 300. concentrated solution 200
H exchanges heat with the dilute solution 100 in the solution heat exchanger 33, is depressurized by the pressure reducing valve 35, and passes through the on-off valve 53, which is open during heating operation, to act as an absorber for heating and cooling load heat. It enters the exchanger 39, is generated in the regenerator 32, is rectified in the rectifier 34, absorbs vapor refrigerant, and becomes 100 L of dilute solution. This dilute solution 100L is pressurized by the solution circulation pump 41, exchanges heat with the concentrated solution 200H in the solution heat exchanger 33, and returns to the regenerator 32 through the dilute solution 34. On the other hand, the vapor refrigerant 300 exits the regenerator 32 and condenses the evaporated absorption liquid together with the rectifier 34 to become a vapor refrigerant of higher purity and is made to act as a condenser via the fourth three-way valve 51. The heat exchanger 39 enters a double pipe 55 provided in the heat exchanger 39. The refrigerant that has been condensed into a liquid here passes through the second check valve 43 and enters the supercooler 40, where the vapor refrigerant obtained in the first and second heat exchangers 37 and 38, which are functioning as evaporators, passes through the second check valve 43. The first and second heat exchangers 37 and 3 exchange heat with each other and are depressurized by the pressure reducing valve 47, and are divided into two and act as an evaporator.
Enter 8. Here, the refrigerant becomes a vapor refrigerant again, returns to one circuit through the first and second three-way valves 48 and 49, and exchanges heat with the supercooler 40, causing the heat exchanger 3 to act as an absorber.
Enter 9. Here, coming from the regenerator 32, the pressure reducing valve 3
4 and absorbed into 200 L of concentrated solution under reduced pressure. FIG. 5 is a cycle diagram showing the case where the absorption heat pump is used for cooling operation. In this figure as well, the black portions of the valves indicate that they are closed. In FIG. 5, during the cooling operation, the double pipe 55 and the heat exchanger 39, which were operating as a condenser and an absorber during the heating operation, are operated as an evaporator, and the heat exchanger, which was operating as an evaporator, is operated as an evaporator. The vessel 38 acts as a condenser, and the heat exchanger 37 likewise acts as an absorber. The concentrated solution 200H discharged from the regenerator 32 is depressurized by the pressure reducing valve 35 to become a low-pressure concentrated solution 200L,
This enters the first heat exchanger 37 acting as an absorber. At this time, since the on-off valve 53 is closed and the check valve 42 is present, 200 L of the concentrated solution enters the heat exchanger 37 as an absorber through the three-way valve 50. The vapor refrigerant is absorbed in the heat exchanger 37 as an absorber, and the three-way valve 48, the solution circulation pump 41, and the solution heat exchanger 3
3 and returns to the regenerator 32. Since the fourth three-way valve 51 is closed, the vapor refrigerant 300 exits the regenerator 32 and passes through the fourth check valve 45 and the second three-way valve 49 to the heat exchanger 38, which is functioning as a condenser. It enters the air, radiates heat, and becomes a liquid refrigerant. Then, it passes through the check valve 44, exchanges heat with the vapor refrigerant in the subcooler 40, is depressurized by the second pressure reducing valve 46, and enters the heat exchanger 39 as an evaporator. The refrigerant that has become a gas-liquid here passes through the fourth three-way valve 51, enters the heat exchanger 39 as an evaporator, and enters the supercooler 40 as a complete vapor refrigerant. Here, it exchanges heat with the liquid refrigerant, passes through the first on-off valve 52 and the first check valve 42, enters the heat exchanger 37 as an absorber, and is absorbed into 200 L of concentrated solution. Cooling operation is performed in this way. The double pipe 55 used in the heat exchanger 39 shown in FIGS. 4 and 5 has a double pipe structure as shown in FIG. 6. During heating operation, as shown in the table below, in this double pipe 55, the outer surface of the outer pipe acts as an absorber and the inside of the inner pipe acts as a condenser. Hot water is obtained by recovering the heat of absorption and the heat of condensation. Further, by performing cooling operation using the cooling/heating switching means, the heat exchanger 39, which has been operating as an absorber and a condenser, now functions as an evaporator. That is, as shown in the table below, the liquid refrigerant evaporates inside the inner pipe of the double pipe 55 to become a gas-liquid mixed refrigerant, and the liquid refrigerant evaporates to become a vapor refrigerant on the outer surface of the outer pipe. Cold water from which the heat of evaporation has been recovered is obtained between the outer tube and the inner tube of the double tube 55. This embodiment operates as described above and has the following advantages.

〔Effect of the invention〕

As described above, according to the present invention, a double pipe is used for the heat exchanger to which the heating and cooling load circuit is connected, and it functions as a condenser and absorber during heating, and as an evaporator during cooling, so that the equipment This has the effect of making it possible to share the device and downsizing the main body of the device.

[Brief explanation of the drawing]

Figure 1 is a system diagram showing a water-lithium bromide absorption heat pump, Figure 2 is a system diagram showing a fluorocarbon-organic ether absorption heat pump, and Figure 3 is an example of the absorption heat pump according to the present invention. Fig. 4 is a cycle system diagram shown to explain the operation of the absorption heat pump during heating operation.
FIG. 5 is a cycle system diagram shown to explain the operation of the absorption heat pump during cooling operation, and FIG. 6 is a sectional view showing the detailed structure of the double pipe used in the same embodiment. 31... Burner, 32... Regenerator, 33... Solution heat exchanger, 34... Rectifier, 35, 46 and 47... First, second and third pressure reducing valves, 37 and 38... First and second heat exchanger 39... Heat exchanger for heating and cooling load circuit, 40... Supercooler, 42, 43 and 4
4...first, second and third check valves, 48, 49,
50 and 51...first, second, third and fourth three-way valves, 52,53 and 54...first, second and third on-off valves.

Claims (1)

[Scope of Claims] 1. A regenerator that heats a dilute solution and separates it into a concentrated solution and high-temperature vapor, a condenser that condenses the high-temperature vapor into a liquid refrigerant, and a pressure reducing valve that lowers the pressure of the liquid refrigerant. An evaporator converts the low-pressure refrigerant into low-pressure vapor, and a concentrated solution from the regenerator is converted into a low-pressure concentrated solution using a pressure reducing valve, and the low-pressure concentrated solution absorbs the low-pressure vapor from the evaporator to create low-pressure diluted solution. In an absorption heat pump that includes an absorber that converts the solution into a solution, a solution circulation pump that boosts the pressure of the low-pressure dilute solution and returns it to the regenerator, and a solution circuit and a refrigerant circuit that connect these devices, an air conditioning load circuit is connected. The heat exchanger is equipped with double pipes, and switches the solution circuit and refrigerant circuit according to the purpose of cooling and heating, and uses the double pipes as an evaporator during cooling and as a condenser and absorber during heating. An absorption type heat pump that is characterized by being able to function. 2. In claim 1, the heat exchanger to which the heating load circuit is connected is configured to flow a concentrated solution to the outside of the outer pipe of the double pipe, flow refrigerant vapor to the inside of the inner pipe, and flow the refrigerant vapor to the inside of the outer pipe. An absorption heat pump characterized in that a hot fluid can be obtained in the heating load circuit by flowing fluid into the heating load circuit. 3. In claim 1, the heat exchanger to which the cooling load circuit is connected has a structure in which liquid refrigerant is caused to flow inside the outer tube and inside the inner tube of the double tube, and to flow inside the outer tube to the cooling load circuit. An absorption heat pump characterized by flowing fluid so that cold fluid can be obtained in a cooling load circuit.