JPH0247670B2 - NETSUHONPUSOCHI - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a refrigeration cycle for a heat pump device using a non-azeotropic mixed refrigerant.

Conventional technology Conventional heat pump devices using non-azeotropic mixed refrigerants are
Capacity control and performance improvement can be achieved by varying the composition of the refrigerant circulating inside the refrigeration cycle. For example, a conventional example as shown in FIG. 2 of JP-A-59-157448 has been proposed. Figure 2 shows an example in which a heat pump device using a non-azeotropic mixed refrigerant is applied as a heating device, where 1 is a compressor, 2 is a three-way valve, 3 is a high temperature side heat exchanger, and 4 and 5 are throttle devices. ,
6 is a three-way valve, 7 is a low temperature side heat exchanger, 8 is a refrigerant rectification column, 9 is a heat exchanger for heating the rectification column, 10 is a high boiling point liquid reservoir, 11 is a throttle device for cooling the rectification column, 12 is a A heat exchanger for cooling the rectification tower, 13 is a low boiling point liquid reservoir, 14,
15 is a flow control valve, 16 and 17 are check valves,
A non-azeotropic mixed refrigerant is sealed inside the refrigeration cycle.

The operation of the heat pump device configured as described above will be explained below. First, when there is no rectification during normal operation, the three-way valves 2 and 6 are open in the direction shown in FIG. It circulates to the expansion device 4, three-way valve 6, expansion device 5, low-temperature side heat exchanger 7, and compressor 1, and the high-temperature side heat exchanger 3 radiates heat, and the low-temperature side heat exchanger 7 absorbs heat. When separating by so-called rectification, which changes the concentration of the refrigerant circulating in the cycle, first switch the three-way valve 2 90 degrees to the right, and transfer the refrigerant discharged from the compressor 1 to the three-way valve 2, which uses heat for heating the rectifier. The high-boiling point liquid is circulated through the exchanger 9, the rectifying tower cooling throttle device 11, the rectifying tower cooling heat exchanger 12, the check valve 16, and the compressor 1, and the high boiling point liquid is passed through the rectifying tower heating heat exchanger 9. The refrigerant liquid rich in high boiling point components in the reservoir 10 is boiled, the refrigerant vapor rich in low boiling point components generated in the rectification column 8 is condensed in the heat exchanger 12 for cooling the rectification column, and the condensed liquid is stored as a low boiling point liquid reservoir. Save it to 13.
The liquid overflowing from the low boiling point liquid reservoir 13 flows down in the rectification column 8 and comes into contact with the refrigerant vapor rising in the rectification column 8 to enhance the rectification effect. In this manner, rectification separation is carried out, and a refrigerant rich in low boiling points is stored in the low boiling point liquid reservoir 13, and a refrigerant rich in high boiling points is stored in the high boiling point liquid reservoir 10. After that, return the three-way valve 2 to its original position, switch the three-way valve 6 90 degrees to the right from the figure, and open the flow rate control valves 14 and 15.
is adjusted to mix a liquid rich in high-boiling point components and a liquid rich in low-boiling point components at a predetermined ratio and flowed toward the expansion device 5 via the check valve 17, after which the three-way valve 6 is returned to its original position.

With the mode of action described above, the refrigerant concentration in the main circuit is varied, and when the main circuit is rich in low boiling point components, high heating capacity is obtained, while when the main circuit is rich in high boiling point components, low heating capacity is obtained. It controls the refrigeration cycle.

Problems to be Solved by the Invention Although it is basically possible to change the refrigerant composition in the heat pump device of the conventional example described above, the following problems occur.

In the first place, in this conventional example, when a refrigerant is subjected to rectification separation in a separator circuit including a rectification column 8, switching of the three-way valve 2 is used as a heat source for driving the rectification column 8. Therefore, no refrigerant flows into the high-temperature side heat exchanger 3, and therefore no heating capacity can be output, which is extremely inconvenient as a heating device.

The refrigerant concentration in the main circuit can be adjusted by adjusting the flow rate adjustment valves 14 and 15 to mix the high boiling point refrigerant in the high boiling point liquid reservoir 10 and the low boiling point refrigerant in the low boiling point refrigerant reservoir 13 in an arbitrary ratio. In this case, in order to adjust the main circuit concentration to the required concentration, the concentration on the main circuit side, the refrigerant concentration in the high boiling point refrigerant reservoir 10, and the low boiling point refrigerant liquid are This is a very complicated control process in which the refrigerant concentration in the reservoir 13 must be detected and the opening degree or opening/closing time of the flow rate regulating valves 14 and 15 must be controlled based on the detected concentration. Also, at this time, in order to maintain the optimum amount of refrigerant in the main circuit, the three-way valve 6 and the flow rate adjustment valves 14 and 15 must be controlled in the same way as described above, which also adds complexity to the cycle. The structure is as follows.

Furthermore, when considering from the perspective of rectification separation, the three-way valve 6
After the high boiling point or low boiling point refrigerant is injected into the main circuit by opening the refrigerant, the refrigerant concentrations in the high boiling point refrigerant reservoir 10 and the low boiling point refrigerant reservoir 13 change, so the three-way valve 2 is then opened. Even if rectification separation is carried out, a problem arises in that the concentrations of the high boiling point refrigerant liquid reservoir 10 and the low boiling point refrigerant liquid reservoir 13 after the rectification separation are different from those during the previous rectification separation.

Therefore, the present invention solves such conventional problems and improves the refrigerant composition to circulate through the main circuit in a heat pump device using a non-azeotropic mixed refrigerant, increasing the reliability of rectification separation without stopping the heating output. The objective is to provide a refrigeration cycle in which the refrigerant can be reliably varied, easily controlled, and the refrigerant on the main circuit side can be adjusted.

Means for Solving the Problems The heat pump device according to the present invention uses a rectifying column that performs a rectifying action as a means for varying the composition of a non-azeotropic mixed refrigerant, and a heat exchanger on the heat source side of the main circuit and a main throttling device. A circuit that branches off from the route between the two and enters the lower part of the rectifying column, and a circuit that enters the route between the main throttle device of the main circuit and the heat source side heat exchanger through the sub-throttle device from the bottom of the rectifying column. It was connected to the main circuit, and the minimum resistance of the sub-throttle device was made greater than the resistance of the main throttle device. Furthermore, the refrigerant concentration in the main circuit is varied by changing the resistance of the sub-throttling device, and when operating with the same main circuit refrigerant concentration as the sealed composition, the resistance of the sub-throttling device is minimized.

By adopting this configuration on the refrigeration cycle, rectification can be performed while obtaining heating output in the main cycle, and the resistance of the sub-throttle device is made greater than the resistance of the main throttling device, so that the circulation Most of the refrigerant flows through the main circuit, allowing stable rectification to occur without disturbing the flow of refrigerant in the rectifier. In addition, by changing the resistance of the sub-throttle device and adjusting the amount of gas generated in the heater, the final concentration of rectification separation can be varied.When rectification is stopped, the amount of gas generated in the heater is eliminated and the rectification is stopped. By disturbing the rectification action in the column with the flow of refrigerant, it is possible to reliably stop the rectification.

Embodiment An embodiment of the heat pump device according to the present invention will be described using the embodiment shown in FIG. 1, which is applied to a heating device.
In FIG. 1, 18 is a compressor, 19 is a load side heat exchanger, 20 is a main throttling device, and 21 is a heat source side heat exchanger, which are connected in order in an annular manner.

On the other hand, the high-pressure outlet of the load-side heat exchanger 19 and the lower part of the rectification column 23 filled with the filler 22 are connected via an intermediate heater 24, and the lower part of the rectification column 23 and the heat source side of the main circuit are exchanged. The inlet of the container 21 is the sub-squeezing device 2.
5. A top cooler 26 and a top reservoir 27 are provided at the top of the rectification column 23 . Although the heat sources of the heater 24 and the cooler 26 are not shown in this embodiment, they are configured so that the discharge gas and suction gas of the compressor 18 are guided, and the refrigerant always flows regardless of the presence or absence of rectification. It is.

In a heat pump device having such a configuration,
The operation will be described with respect to the time of rectification to vary the main circuit refrigerant concentration in heating operation and the time of no rectification to make the main circuit refrigerant concentration the same as the sealed composition.

First, during rectification, a portion of the high-pressure liquid refrigerant discharged from the load-side heat exchanger 19 is heated by the heater 24 to generate some gas, which flows into the lower part of the rectification column 23 . The gas components generated in the heater 24 are sent to the rectification column 23
It rises inside the tank, condenses and liquefies in the cooler 26, and flows into the reservoir 2.
7 to the upper part of the rectifying column 23 and descending inside the rectifying column 23. At this time, the rising gas and the descending liquid exchange substances and heat to perform a rectifying action, and a low boiling point rich refrigerant is stored in the reservoir 27. Therefore,
From the lower part of the rectification column 23, the high-boiling point rich refrigerant passes through the sub-throttling device 25, merges with the main circuit side refrigerant, and flows into the heat source side heat exchanger 21. At this time, since the resistance of the sub-throttling device 25 is made larger than that of the main throttling device 20, most of the circulating refrigerant flows through the main circuit side, and only a small amount of refrigerant flows into the rectifying column 23. This allows for stable rectification without disturbing the rectification action within the tank. At this time, if the resistance of the sub-throttle device 25 is made variable, the amount of gas generated from the heater 24 will change.For example, by reducing the resistance of the sub-throttle device and increasing the branched flow rate to the rectifier side, the gas generated If the amount is reduced, the separation effect in rectification separation will not proceed, and in the method of storing low boiling point components as in this embodiment, the concentration of low boiling point components in the reservoir 27 will not be high, and therefore the concentration on the main circuit side will decrease. The refrigerant composition is also high in low boiling point components. On the other hand, if the resistance of the sub-throttle device is increased to reduce the branched flow rate to the rectifier side and increase the amount of generated gas, the separation action in rectification separation will proceed, and low boiling point gas will be present in the reservoir 27. The refrigerant is stored, and as a result, the concentration on the main circuit side becomes a refrigerant composition containing many high boiling point components.

Furthermore, as the main circuit concentration changes due to the rectification effect, the optimum amount of refrigerant on the main circuit side changes. When the refrigerant flowing through the main circuit is rich in low-boiling point components, the optimum amount of refrigerant increases; on the other hand, when it is rich in high-boiling point components, the optimum amount of refrigerant decreases. By storing the refrigerant, adjustment can be made by increasing or decreasing the amount of stored refrigerant in proportion to the density difference.

Next, when the rectification separation is stopped and the main circuit concentration is operated with the initially charged refrigerant composition, the sub-throttle device 25
The rectifying action is stopped by opening the valve and increasing the branch flow rate to eliminate the amount of gas emitted by the heater 24.

In this way, in the present invention, the rectification action can be performed even during heating operation in the main circuit, and the concentration in the main circuit can be changed.

In this embodiment, only the heating circuit is described, but it is possible to add a four-way valve or the like to perform the rectifying action even during cooling, and perform the same operation as described above.

Furthermore, although this embodiment describes a case where a low-boiling point refrigerant is stored through rectification, it may also be applied to a refrigeration cycle (not shown) in which a high-boiling point refrigerant is stored in a reservoir placed at the bottom of a separator. It has similar effects.

Effects of the Invention The heat pump device of the present invention uses a non-azeotropic mixed refrigerant, connects the rectification column to the high pressure or intermediate pressure of the main circuit, and connects the return from the rectification column to the low pressure of the main circuit. By making the resistance of the sub-throttle device larger than the resistance of the main throttle device, rectification separation can be reliably performed while heating operation is performed in the main circuit.

In addition, by adding a configuration that changes the resistance of the sub-throttle device according to the desired main circuit concentration and reduces the resistance when rectification is stopped, the main circuit concentration can be adjusted as desired by adjusting the branch flow rate and varying the separation concentration. Can be set. Furthermore, the amount of refrigerant stored in the reservoir can be adjusted according to the separated concentration, and the amount of refrigerant on the main circuit side can be maintained at an optimum level.

[Brief explanation of drawings]

FIG. 1 is a principle diagram of a heat pump device according to an embodiment of the present invention, and FIG. 2 is a principle diagram of a conventional heat pump device. 18...Compressor, 19...Load side heat exchanger, 2
0... Main expansion device, 21... Heat source side heat exchanger, 2
3... Rectification column, 24... Heater, 25... Sub-throttling device, 26... Tower top cooler, 27... Tower top reservoir.

Claims (1)

[Claims] 1. A main circuit in which at least a compressor, a load-side heat exchanger, a main throttling device, and a heat source-side heat exchanger are connected in a ring;
A rectification circuit equipped with a rectification column, a tower top cooler, a reservoir, and a column bottom heater is branched from the path between the load-side heat exchanger and the main throttling device in the main circuit to the lower part of the rectification column. The connecting circuit is connected to the circuit that connects from the lower part of the rectifying column through the sub-throttle device to the path between the main throttling device of the main circuit and the heat source side heat exchanger, and the minimum resistance of the sub-throttling device is A heat pump device characterized in that the resistance is greater than that of a throttle device. 2. The main circuit refrigerant concentration is varied by varying the resistance of the sub-throttling device, and when the main circuit is operated with the same refrigerant concentration as when it was sealed, the resistance of the sub-throttling device is minimized. The heat pump device according to item 1.