JPH0739887B2 - Heat pump device - Google Patents

Description

The present invention relates to a heat pump device, particularly a heating / cooling device, in which a non-azeotropic mixed refrigerant is used, and the concentration of the refrigerant flowing in the main circuit is varied to constantly adapt to the load. The present invention relates to a heat pump device that generates cooling and heating capacity.

2. Description of the Related Art Conventionally, as a method of varying the capacity of a heat pump device, a non-azeotropic mixed refrigerant is used as a refrigerant, and a separator is used to separate a high boiling point refrigerant and a low boiling point refrigerant, thereby changing the refrigerant composition of the main circuit. A variable capacity is proposed. This is to change the suction specific volume by changing the refrigerant composition to change the circulation amount.The rectification method is used as the separation method, and a method to add such method to the method of changing the compression rotation speed is proposed. Has been done.

As a prior invention for such a method, we have proposed the one shown in FIG. In FIG. 5, 1 is a compressor,
2 is a four-way valve, 3 is a load side heat exchanger, 4 is a main throttle device, 5
Is a heat source side heat exchanger and constitutes the main cycle.

Further, as a sub-cycle connected in parallel to the main cycle, a pipe 7 that connects the load-side heat exchanger 3 and the main expansion device 4 to the separator 6, a column bottom of the separation device 6 and the main expansion device 4 are connected.
A pipe 8 is provided to connect between the heat source side heat exchanger 5 and the heat source side heat exchanger 5. In addition, the expansion devices 9 and 10 are installed in the pipes 7 and 8.
Are provided in parallel with the check valves 11 and 12. Separation 6
A pipe 13 and a reservoir 14 and a reflux pipe 15 are provided in an annular shape from the top of the column, and a top heat exchanger 16 is attached to the pipe 13.
In addition, the bottom heat exchanger 17 is installed in the pipes 7 and 8 or at the bottom of the tower.
Is attached. Furthermore, from the reservoir 14 to the pipe 8 the pipe 18
Is provided via a solenoid valve 19 that can be opened and closed.

The mode of action in such a prior invention is as follows.
That is, when the solenoid valve 19 is closed during heating, part of the liquid refrigerant condensed in the load side heat exchanger 3 flows into the separator 6 through the check valve 11. At this time, it is heated by the bottom heat exchanger 17 using a high temperature source in the cycle, and mainly the low boiling point component in the refrigerant is vaporized to generate a gas component and enter the separator 6. The gas component entering the separator 6 rises in the separator 6,
Passing through the pipe 13, it is cooled and liquefied by the overhead heat exchanger 16 using a low temperature source in the cycle and stored in the reservoir 14, and the reflux pipe
From 15 the liquid is refluxed to the top of the tower. The liquid refrigerant refluxed to the top of the tower is a gas component that rises while descending in the separator 6,
Gas-liquid contact heat exchange is performed on the surface of the packing material filled in the separator 6, and as a result, low boiling point components are stored in the reservoir 14, and therefore the heat exchange on the heat source side through the expansion device 10 through the pipe 8. The refrigerant entering the vessel 5 becomes a high boiling point refrigerant, and the main cycle can be gradually made to have a high boiling point rich refrigerant composition,
Low heating capacity Highly efficient operation becomes possible.

Further, in order to restore the main cycle to the original composition of the composition rich in low-boiling point components and operate with high heating capacity, the solenoid valve 19 of the pipe 18 connected to the pipe 8 from the reservoir 14 is opened, so that the pipe 7
The inflowing refrigerant is mainly from the separator 6 → the reservoir 14 → the pipe 18 →
It passes through the throttle 10, and the remaining part passes through the bottom of the separator 6 → the pipe 8 → the throttle 10. At this time, the flow of the liquid refrigerant from the top of the column necessary for rectification is hindered in the separator 6 and the separation is stopped, and as a result, the refrigerant composition rich in low boiling point components of the original enclosed composition is obtained during the main cycle. You can

When the cooling operation is performed, the four-way valve 2 is switched, and when the solenoid valve 19 is closed, a part of the liquid refrigerant condensed in the heat source side heat exchanger 5 passes through the check valve 12 to the separator 6 through the pipe 8. Inflow. At this time, if the bottom heat exchanger 17 is configured to be able to heat the pipe 8 as well, the low boiling point component in the refrigerant is mainly vaporized to generate a gas component and enters the separator 6, which has the same effect as during heating separation. The main cycle can have a refrigerant composition rich in high-boiling components.

Also, when operating with a refrigerant composition rich in low boiling point components, which is the same as the enclosed composition, by opening the solenoid valve 19, the refrigerant downflow in the separator 6 increases and the rising gas rises, contrary to the time of warming. The flow is obstructed and the separation is stopped, resulting in a refrigerant composition rich in low boiling components of the original enclosed composition during the main cycle.

Problems to be Solved by the Invention In the heat pump device of the prior invention described above, basically, the composition of the co-refrigerant during cooling and heating is variable, and the variation is surely performed. However, such a separation action is essentially a substance exchange, which takes a long time to reach the desired separation concentration. In order to accelerate the separation time, it is sufficient to increase the amount of treatment in the separator. The method is to increase the amount of refrigerant flowing into the separator 6, and to increase the amount of heat in the bottom heat exchanger 17 and the heat of the top of the tower. The amount of gas generated at the bottom of the column and the amount of condensate at the top of the column may be increased by increasing the amount of cooling in the exchanger 16, and the amount of treatment in the separator 6 may be increased. However, if the column diameter of the separator 6 is fixed and the amount of inflow is simply increased, the optimum liquid flow and gas rise in the separator 6 are not maintained, and the separation action stops. Further, if the heating amount is simply increased, a so-called flooding phenomenon occurs and the separation action stops, and when a high temperature source of the main cycle such as the discharge gas of the compressor 1 is used as the heating source, heat exchange on the load side is performed. There is a problem in that the temperature of the refrigerant entering the vessel 3 decreases, and the capacity is greatly reduced during heating and cooling. In addition, when the heating amount is increased in this way, the cooling amount must also be increased. Therefore, the bottom heat exchanger
17, There is a problem that the overhead heat exchanger 16 becomes large.

Means for Solving the Problems In the present invention, therefore, an inlet gas is used as a cooling source of the overhead heat exchanger, and the refrigerant at the inlet of the overhead heat exchanger, which serves as a cooler of the separator during the separation operation, is in a wet state. In addition, the opening of the main throttle device is increased for a predetermined time.

Action According to the present invention having the above-described configuration, the opening of the main expansion device is increased at the start of the separation action to make the main cycle a slightly moist cycle, and the refrigerant flow in the cooler when the cooling source is suction gas is controlled. By using two-phase liquid, the heat transfer coefficient is increased, and the degree of supercooling of the refrigerant flowing into the separator from the load side heat exchanger is suppressed to increase the gas generation amount in the separator, and these effects are desirable. The separation time up to the separation concentration of can be shortened.

Example The basic configuration of the heat pump device according to the present invention is shown in FIG.
1 to 19 are the same constituent elements as those of the prior invention of FIG. A feature of the present invention is that the suction gas of the compressor 1 is connected as a cooling source of the overhead heat exchanger 16 and the opening degree of the main expansion device 4 can be adjusted by, for example, a suction temperature sensor 20. FIG. 2 shows the operation of the solenoid valve 19 and the main throttle device 4 during the separation operation. The heating operation will be described. When the heating load becomes small and a command for heating capacity reduction is input to the control circuit (not shown) by the intake temperature sensor 20 of the load side heat exchanger 3, for example, and the main cycle concentration is changed to the high boiling point refrigerant composition, FIG. The solenoid valve 19 that has been opened is closed as shown in FIG. In this case, the separating action proceeds by the following action. That is, a part of the liquid refrigerant condensed in the load side heat exchanger 3 flows into the separator 6 through the check valve 11. At this time, the bottom heat exchanger using a high temperature source during the cycle 17
The low boiling point component in the refrigerant is mainly vaporized to generate gas and enter the separator 6. The gas component that has entered the separator 6 rises in the separator 6, passes through the pipe 13, and is cooled by the overhead heat exchanger 16 that functions as a cooler using the refrigerant sucked in the compressor 1 as a low temperature source during the cycle. Liquefied reservoir 14
And the electromagnetic valve 19 is closed, the liquid is refluxed from the reflux pipe 15 to the top of the tower. The liquid refrigerant recirculated to the top of the tower performs gas-liquid contact heat exchange between the gas components rising in the separator 6 while descending in the separator 6 and the surface of the packing material filled in the separator 6, and as a result, the reservoir 14 The low boiling point component is stored therein, and therefore the refrigerant that enters the heat source side heat exchanger 5 through the expansion device 10 from the pipe 8 becomes a high boiling point refrigerant, and the main cycle gradually becomes a high boiling point refrigerant. It can be a composition.

At this time, in the present invention, during the separation operation, the opening degree of the expansion device 4 is increased so that the refrigerant entering the overhead heat exchanger 16 is in a wet state for a predetermined time from the start. Further, the movement of the cycle when the opening of the main expansion device 4 is increased and when it is decreased is shown on the Mollier diagram. In the state in which the opening of the main expansion device 4 is made small so that the heat source of the separation top heat exchanger 16 is used as the suction gas of the compressor 1 to ensure an appropriate degree of superheat, the inlet at the top heat exchanger 16 Although the refrigerant state A becomes superheated gas, in the present invention, the opening degree of the main expansion device 4 is increased at the start of separation to shift the refrigerant state at the inlet of the overhead heat exchanger 16 to the wet point B. Further, the state of the refrigerant at the inlet to the separator 6 becomes a large point of the supercooling at the point C when the opening degree of the main expansion device 4 is made small, but it becomes a point by increasing the opening degree of the main expansion device 4 as in the present invention. Transition to a state in which the degree of supercooling of D is small. Further, as shown in the operation diagram of FIG. 2, the opening degree of the main expansion device 4 is increased only for a predetermined time from the start of the separation until the desired concentration is reached, and thereafter, the main expansion device 4 is continued while the separation action is continued. The opening of No. 4 is reduced so that optimum operation can be performed as a cycle.

Thus, opening the main diaphragm device 4 at the start of separation and shifting the cycle as described above has the following effects.

That is, by setting the inlet refrigerant state in the overhead heat exchanger 16 to the wet state point B, the heat transfer coefficient in the overhead heat exchanger 16 can be improved, which is the processing amount at the time of separation action. The reflux amount can be increased and the separation time can be shortened. Further, by shifting the state of the refrigerant inlet to the separator 6 from the state of the point C where the degree of supercooling is large to the point D where the degree of supercooling is small, the gas generation at the inlet of the separator 6 is facilitated, and the amount of generated gas is increased. Can be increased, and as a result, the amount of reflux, which is a processing amount, is increased,
The separation time can be shortened.

FIG. 4 shows a change in concentration of the main cycle when the opening adjustment of the main throttle device 4 of the present invention is applied in comparison with a concentration change when the opening is not adjusted. Is the time that has elapsed since the start of separation and the lower side of the vertical axis indicates the low boiling point component concentration of the main cycle, and the upper side indicates the opening degree of the main expansion device 4, and the solid line indicates the present invention. It has been confirmed that, when the opening is adjusted as described above, the desired concentration achievement time can be shortened to about half by adjusting the opening when the broken line does not adjust the opening. Further, as shown in FIG. 4, the opening of the main expansion device 4 is made small after reaching the separation concentration so that optimum operation can be performed as a cycle, but it was also confirmed that the separation concentration is maintained even in this state. There is. Needless to say, the opening degree of the main expansion device 4 may be adjusted not only by using an electronically controlled expansion valve or the like but also by switching between two expansion devices having different resistances.

Effects of the Invention As described above, in the heat pump device according to the present invention, the opening of the main expansion device is increased for a predetermined time at the start of the separation operation to bring the refrigerant inlet refrigerant into a wet state, and heat in the cooler is increased. Achieving the desired cycle concentration by the dual action of increasing the transfer rate to increase the amount of reflux and further reducing the degree of supercooling of the refrigerant at the inlet of the separator to increase the amount of gas generated at the inlet of the separator to increase the amount of reflux. This has the effect of significantly shortening the time until.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of the present invention, FIG. 2 is a diagram showing a basic operation of a main throttle device opening of the present invention, and FIG. 3 is a diagram showing a cycle operation according to a main throttle device opening, FIG. 4 is a diagram showing a separation concentration change with and without main throttle device opening adjustment,
FIG. 5 is a diagram showing an embodiment of our prior invention. 1 ... Compressor, 3 ... Load side heat exchanger, 4 ... Main throttle device, 5 ... Heat source side heat exchanger, 6 ... Separator, 14 ... Separator, 16 ... Tower heat exchange Container, 19 ... Solenoid valve.

Claims (1)

[Claims] 1. A main cycle in which a non-azeotropic mixed refrigerant is sealed and a compressor, a load side heat exchanger, a main expansion device, and a heat source side heat exchanger are connected in an annular manner, and a cooler and a reservoir are provided in the upper part. And a separator for separating the non-azeotropic mixed refrigerant in the main cycle by constituting a circuit for returning to the upper portion again and connecting one end between the load side heat exchanger and the expansion device. ,
A first pipe having the other end connected to the separator and a heating means provided on the way, and one end connected to the tower bottom of the separator and the other end connected to the expansion device and the heat source side heat exchanger. And a second pipe connected between them, the compressor suction refrigerant in the main cycle is used as a cooling source, and the opening degree of the main expansion device is increased for a predetermined time at the start of the separation operation to perform the cooling. A heat pump device characterized in that the refrigerant state at the inlet of the vessel is in a wet state.