JPS6256416B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a refrigerator-freezer, and more particularly to a refrigerator-freezer of a two-temperature evaporation type using a multi-effect cycle.

Conventional household refrigerator-freezers generally cool the air in the freezer compartment and refrigerator compartment using one evaporator. For this reason, air at a relatively high temperature level, such as in a refrigerator room, is cooled by a low-temperature evaporator that can be cooled down to a low temperature level, such as in a freezer room, which forces inefficient operation. Ta.

To improve this, a theoretically efficient multi-effect cycle is known.

FIG. 1 is a cycle configuration diagram of a two-temperature evaporative refrigerator-freezer using a conventional multi-effect cycle. In this FIG. 1, 1 is a compressor, 12 is a compressor 1
13 is a roller of the compressor 1; 19 is a vane that moves up and down as the roller 13 rotates and slides and divides the inside of the cylinder 12 into two chambers, a compression chamber and a suction chamber; 18 is a vane; 19 is a vane pressing spring that applies a pressing force.

Reference numeral 25 denotes an injection exit port that opens when the sliding position of the roller 13 escapes near an intermediate pressure during the compression stroke of the cylinder 12.

2 is a discharge pipe, 3 is a condenser, 4 is a first throttle, 5 is a gas-liquid separator provided after the first throttle 4, 6 is a
A high-temperature side evaporator whose inlet 6a and outlet 6b are respectively connected to the liquid-side outlet 5c and gas-side outlet 5b of the gas-liquid separator 5, and the high-temperature side evaporator 6 evaporates air from a refrigerator compartment (not shown). Cooling. 7 is a second throttle provided after the gas-liquid separator 5; 8 is a low-temperature side evaporator; the low-temperature side evaporator 8 cools the air in the freezer compartment (not shown). Note that 9 is a return pipe.

The cooling effect of the conventional two-temperature evaporative refrigerator-freezer using a multi-effect cycle constructed as described above will be explained with reference to FIG.

FIG. 2 is a Mollier diagram of a multi-effect cycle. In FIG. 2, between AB is adiabatic compression of the refrigerant on the low-temperature side evaporator 8, and between CD is adiabatic compression of the mixed refrigerant returned from the low-temperature side and high-temperature side evaporators 8 and 6.
Heat is dissipated by condenser 3 between DE and first throttle 4 between EF
The first expansion due to
They are shown below.

First, when the refrigerant is input to the compressor 1, the refrigerant in the cylinder 12 of the compressor 1 is compressed by the roller 13 which rotates driven by the rotary eccentric shaft 14, and pushes up the discharge valve 17 from the discharge port 15 with a high pressure of _Pd . Then, the high-temperature, high-enthalpy superheated vapor refrigerant D is discharged into the closed container 16 and guided to the condenser 3 via the closed container discharge port 20 and the discharge pipe 2. This refrigerant radiates heat in the condenser 3 and becomes a high-pressure, low-enthalpy liquid refrigerant E.
, the pressure is reduced by the first throttle 4, and it becomes a low enthalpy machine liquid mixed refrigerant F with an intermediate pressure P _n , which flows into the inlet 5.
The refrigerant enters the gas-liquid separator 5 from a and is separated into liquid refrigerant and gas refrigerant. A part of the separated liquid refrigerant G passes through the liquid outlet pipe 22, enters the high temperature side evaporator 6 from the inlet 6a and is evaporated, is separated by the gas-liquid separator 5, and is merged through the gas outlet pipe 21. tube 26
The medium-pressure, high-enthalpy gas refrigerant flows into the cylinder 12 from the injection exit port 25, which opens into the cylinder 12 during the compression stroke, through the injection exit pipe 23 and the injection exit inlet 24. It becomes C and is sucked in. The remaining part of the separated liquid refrigerant is further reduced in pressure by the second throttle 7, becomes a gas-liquid mixed refrigerant H with low pressure _Ps and low enthalpy, and is led to the low-temperature side evaporator 8, where it absorbs heat. The refrigerant A is sucked into the cylinder 12 of the compressor 1 during the suction stroke through the return pipe 9, suction pipe 10, and suction port 11 as a low-pressure, high-enthalpy gas refrigerant A, and then enters the compression stroke again and is circulated.

In this cycle, the power source for the drive source of the compressor 1 is connected to a temperature sensor installed in a refrigerator compartment (not shown) that is cooled by the high-temperature side evaporator 6 or in a freezing compartment that is cooled by the low-temperature side evaporator 8. (not shown)
It will run continuously until it is shut off.

By using the multi-effect cycle as described above in a refrigerator-freezer, the air in the relatively high temperature refrigerator compartment is transferred to the high temperature side evaporator 6, and the air in the freezer compartment, which is low in temperature, is transferred to the low temperature side evaporator 8. Since cooling can be performed at an optimally set evaporation temperature, the efficiency is improved compared to the refrigerator-freezer that uses a refrigeration cycle that cools a freezer compartment and a refrigerator compartment with one evaporator.

However, the conventional two-temperature evaporative refrigerator-freezer using a multi-effect cycle shown in Figure 1 has the following drawbacks (a) to (h), so it has not yet been commercialized. be.

(b) Only a part of the circulating refrigerant on the discharge side of the compressor 1 flows into the high temperature side evaporator 6, and the flow rate is small, so the heat transfer coefficient in the pipes of the high temperature side evaporator 6 is low, and the heat transfer coefficient is correspondingly large. Required evaporator.

(b) The vertical relationship between the installation positions of the gas-liquid separator 5 and the high-temperature side evaporator 6 has a great effect on performance.
However, if the high temperature side evaporator 6 is too low, too much liquid refrigerant enters it and cannot be completely evaporated, causing the compressor 1
This causes liquid to return. Conversely, if the high temperature side evaporator 6 is too high, less liquid refrigerant will enter there, and the refrigerant will be superheated, reducing the cooling capacity. For this reason, it has been difficult to accommodate the gas-liquid separator 5 and the high-temperature side evaporator 6 in a narrow space inside the refrigerator while maintaining an appropriate positional relationship.

(c) Due to load fluctuations in the refrigerator and freezer compartments, the amount of refrigerant flowing through the high-temperature side evaporator 6 and the low-temperature side evaporator 8 varies, causing an imbalance. That is, if the load on either one of the evaporators is small, liquid returns to the compressor 1, which is a drawback.

(d) Cooling of the freezer compartment and refrigerator compartment is performed synchronously while the compressor 1 is operating, and in case of excessive cooling, the compressor 1 is stopped, which is an intermittent operation, generally at a rate of about 2 times per hour.
I was walking around. Therefore, when the compressor 1 is stopped, the high-temperature refrigerant remaining in the condenser 3 flows into the high-temperature side and low-temperature side evaporators 6 and 8 through the first throttle 4, the gas-liquid separator 5, and the second throttle 7. There was a drawback that the superheated gas refrigerant and high temperature refrigerating machine oil flowed back from the suction port 11 of the compressor 1 and flowed into the low temperature side evaporator 8, degrading the cooling performance.

(E) In addition, since the freezing and refrigerating compartments are cooled synchronously while the compressor 1 is operating, the cylinder has a large internal volume with a large displacement that allows refrigerant to flow simultaneously to the high-temperature side and low-temperature side evaporators 6 and 8. required.

(F) Simultaneous cooling of the freezer and refrigerator compartments was performed intermittently, starting and stopping approximately twice in an hour, which caused an unpleasant noise when the compressor 1 was started and stopped.

(G) When defrosting the low-temperature side evaporator 8 in the freezer compartment, the compressor 1 is stopped and the defrost heater attached to the evaporator is energized. remains, and it is necessary to heat this liquid refrigerant and frost together, which requires a large amount of heater power.

(H) The refrigeration cycle of a refrigerator is designed based on the maximum load even if the ambient temperature changes from 30°C in the summer to 15°C in the winter, and the internal cylinder volume of the compressor 1 is determined in particular. For this reason, there is excess refrigeration capacity in the winter, and the number of interruptions becomes extremely high.
The above-mentioned drawback (d) will further increase.

The present invention eliminates the drawbacks of the prior art described above, improves the heat transfer coefficient of the high temperature side evaporator, and eliminates restrictions on the positional relationship between the high temperature side evaporator and the gas-liquid separator. A refrigeration cycle configuration that enables downsizing, prevents liquid from returning to the compressor by improving the imbalance in refrigerant flow between the high-temperature side evaporator and the low-temperature side evaporator, and adapts to changes in heat load due to ambient temperature. The objective is to provide a refrigerator-freezer that achieves significant power savings.

The refrigerator-freezer according to the present invention has a configuration in which the discharge port of the compressor is connected to a condenser, a first throttle, and a gas-liquid separator in sequence, and is equipped with a high-temperature side evaporator, a second throttle, and a low-temperature side evaporator. In a two-temperature evaporative refrigerator-freezer,
A gas outlet pipe is provided to connect the gas side outlet of the gas-liquid separator and the inlet of the high-temperature side evaporator, and the outlet side of the high-temperature side evaporator is connected to the injection exit port of the compressor. The liquid side outlet is provided with a valve part that allows flow to only one side and the other side, one of which is connected to the inlet of the high temperature side evaporator, the other to a second throttle, and the outlet of this second throttle is connected to the low temperature side evaporator. A valve part connected to the inlet side and flowing only to one side and the other side is provided on the outlet side of the low-temperature side evaporator, one of which is connected to the suction port of the compressor, and the other is connected to the injection exit port of the compressor. It is connected.

More details are as follows.

In a two-temperature evaporative refrigerator-freezer equipped with at least a compressor, a condenser, a first throttle, a gas-liquid separator, a high-temperature side evaporator, a second throttle, and a low-temperature side evaporator, the outlet of the condenser and the gas-liquid separation The inlet of the gas-liquid separator is connected to the inlet of the gas-liquid separator through a first throttle, the gas-side outlet of the gas-liquid separator is connected to the inlet of the high-temperature side evaporator, and a branch pipe is provided at the liquid-side outlet of the gas-liquid separator. One branch is connected to the inlet of the high temperature side evaporator via an electromagnetic shut-off valve, and the other branch is connected to the low temperature side evaporator via a second throttle. Furthermore, a branch pipe is provided on the outlet side of this low-temperature side evaporator, one branch of which is connected to the injection exit pipe via an electromagnetic on-off valve, and the other branch is connected to the return pipe via an electromagnetic on-off valve. This is how it was done.

This creates an in-jet refrigeration cycle that passes through the high-temperature side evaporator, an in-die extension pipe, and connects to the cylinder that opens in the middle of the compression stroke of the compressor, and a main refrigeration cycle that passes through the low-temperature evaporator and connects to the cylinder from the compressor suction port. It is possible to form an injection refrigeration cycle that passes through the evaporator on the low temperature side, and then the evaporator on the low temperature side, which connects to the cylinder that opens in the middle of the compression stroke of the compressor via the injection pipe and the evaporator on the low temperature side. By switching, the low-temperature side evaporator is cooled by selecting a two-path refrigeration cycle (main refrigeration cycle or injection refrigeration cycle via the low-temperature side evaporator) according to the load caused by the outside temperature, and the electromagnetic on-off valve is By switching, the high temperature side evaporator and the low temperature side evaporator can be cooled alternately.

The present invention will be explained below with reference to Examples.

FIG. 3 is a cycle configuration diagram of a refrigerator-freezer according to an embodiment of the present invention.

In FIG. 3, the same parts as in FIG. 1 are denoted by the same numbers.

In this refrigerator-freezer, a discharge port 15 of a compressor 1 is connected to a condenser 3, a first throttle 4, and a gas-liquid separator 5 in sequence, and a high-temperature side evaporator 6, a second throttle 7, and a low-temperature side evaporator 8. It is a two-temperature evaporation type refrigerator-freezer equipped with a liquid-side outlet 5c provided at the bottom of the container of the gas-liquid separator 5, and a first branch pipe 31, which is connected to a valve part that flows only to one side and only to the other side. An electromagnetic on-off valve 28 and a second electromagnetic on-off valve 27 are provided, and the liquid side outlet 5
One branch of the branch pipe 31 attached to c is connected to the inlet of the high temperature side evaporator 6 via the first electromagnetic on-off valve 28 and the merging pipe 30, and the other branch is connected to the second electromagnetic on-off valve 2.
It is connected to the second diaphragm 7 via 7. The outlet of the second throttle 7 is connected to the inlet of the low-temperature side evaporator 8. On the other hand, the gas side outlet 5b of the gas-liquid separator 5 and the confluence pipe 3 located before the inlet of the high temperature side evaporator 6 are connected by a gas outlet pipe 29. The outlet side of the high temperature side evaporator 6 is
It is connected to an injection exit port 25 of the compressor 1 via an injection exit pipe 23, a merging pipe 35, and an injection exit inlet 24.

Further, on the outlet side of the low-temperature side evaporator 8, there are branch pipes 36, which are connected to valve parts that flow only to one side and only to the other side.
A third electromagnetic on-off valve 33 and a fourth electromagnetic on-off valve 34 are provided, and one branch of a branch pipe 36 attached to the outlet side of the low-temperature side evaporator 8 is connected to the third electromagnetic on-off valve 33 and a return pipe 9. The other branch is connected to the suction port 11 of the compressor 1 via a fourth electromagnetic on-off valve 34, a merging pipe 35, and an injection exit port 25 of the compressor 1 via an injection exit inlet 24.

In this way, the injection refrigeration cycle that connects the high temperature side evaporator 6, injection extraction pipe 23, merge pipe 35, injection exit inlet 24, and injection exit port 25, the low temperature side evaporator 8, the branch pipe 36, and the third electromagnetic A main refrigeration cycle connecting the on-off valve 33, the return pipe 9, the suction pipe 10, and the suction port 11, the low-temperature side evaporator 8, the branch pipe 36,
An injection refrigerating cycle is formed via the low-temperature side evaporator that connects the fourth electromagnetic on-off valve 34, the merging pipe 35, the injection exit inlet 24, and the injection exit port 25.

By configuring as described above, first, when the heat load is large in summer, the third solenoid on-off valve 33 is opened and the fourth solenoid on-off valve 34 is closed, and the two systems of the injection refrigeration cycle and the main refrigeration cycle are closed. Form. Then, when the first electromagnetic on-off valve 28 is closed and the second electromagnetic on-off valve 27 is opened to circulate the refrigerant by the compressor 1, the refrigerant passes through the discharge pipe 2, the condenser 3, and is throttled by the first throttle 4. Thereafter, the gas enters the gas-liquid separator 5 through the inlet 5a and is separated into gas and liquid. The separated gas refrigerant exits from the gas side outlet 5b and flows to the high temperature side evaporator 6 via the gas outlet pipe 29 and the merging pipe 30. Here, the high-temperature side evaporator 6 is slightly cooled (pre-cooled) only by the gas refrigerant, and the gas refrigerant is supplied to the injection exit pipe 23 and the confluence pipe 3.
5, enters the cylinder 12 through the injection exit inlet 24 and injection exit port 25.

On the other hand, the liquid refrigerant separated into gas and liquid is transferred to the gas-liquid separator 5.
After passing through the liquid side outlet 5c of the liquid side through the branch pipe 31 and the second electromagnetic on-off valve 27 and being throttled by the second throttle 7, it is evaporated in the low temperature side evaporator 8, and the low temperature side evaporator 8 is cooled by the main refrigeration cycle. , branch pipe 36, third electromagnetic on-off valve 33, return pipe 9, suction pipe 10, compressor 1
is sucked into the cylinder 12 through the suction port 11.

Next, when the freezing compartment (not shown) having the low-temperature side evaporator 8 is sufficiently cooled, the temperature sensor in the freezing compartment opens the first electromagnetic on-off valve 28 and switches the second electromagnetic on-off valve 27 to close. . This allows the liquid refrigerant to flow into the high temperature side evaporator 6, which has a small cooling capacity.
It evaporates and the high temperature side evaporator 6 is cooled by the injection refrigeration cycle. When this refrigerator compartment (not shown) is sufficiently cooled, the compressor 1 is stopped by a temperature sensor in the refrigerator compartment. However, if the temperature of the freezer compartment rises during cooling of the refrigerator compartment and cooling is required, the compressor 1 will continue to operate without stopping.
The first and second electromagnetic on-off valves 2 are activated by the temperature sensor in the freezer compartment.
8 and 27 to return to the previous state and perform cooling.

In addition, when the heat load is low in winter,
The third electromagnetic on-off valve 33 is closed and the fourth electromagnetic on-off valve 34 is opened to form an injection refrigeration cycle passing through the high temperature side evaporator 6 and an injection refrigeration cycle passing through the low temperature side evaporator. Then, the first electromagnetic on-off valve 28 and the second electromagnetic on-off valve 27 are alternately opened and closed by the temperature sensor in the freezer compartment, and the liquid refrigerant flows to the high-temperature side evaporator 6 or the low-temperature side evaporator 8. Cool the freezer compartment as described above.

Defrosting of the low-temperature side evaporator 8 in the freezer compartment is performed by opening the first electromagnetic on-off valve 28 and closing the second electromagnetic on-off valve 27 when the temperature sensor in the freezing room detects a preset defrosting start temperature. The third electromagnetic on-off valve 33 is opened, the fourth electromagnetic on-off valve 34 is closed, the liquid refrigerant in the low-temperature side evaporator 8 is sucked out by the compressor 1, and while the high-temperature side evaporator 6 is being cooled, the low-temperature side evaporation is performed. This is done by energizing a defrosting heater (not shown) attached to the container 8.

FIG. 4 is a cycle configuration diagram of a refrigerator-freezer according to another embodiment of the present invention.

In FIG. 4, the same parts as in FIG. 3 are denoted by the same numbers. And 32 and 37 are
They are a first electromagnetic on-off three-way valve and a second electromagnetic on-off three-way valve, respectively, which relate to valve parts that flow only to one side and only to the other. It is provided at the position of the flow branch pipes 31 and 36 in the embodiment shown in FIG.

The operation of this embodiment is exactly the same as that of the embodiment shown in FIG. 3 described above.

In the embodiment shown in FIGS. 3 and 4, the gas outlet 5b of the gas-liquid separator 5 and the confluence pipe 30 in front of the inlet of the high-temperature side evaporator 6 are connected by the gas outlet pipe 29. The gas side outlet 5b of the liquid separator 5 and the inlet of the high temperature side evaporator 6 are connected directly to the gas outlet pipe 29.
You can also connect with

The refrigerator-freezer having the refrigeration cycle configuration of each of the embodiments described above has the following effects.

(1) Liquid refrigerant can alternately flow through the low-temperature side evaporator 8 and the high-temperature side evaporator 6, and when only the high-temperature side evaporator 6 is flowing, the compressor 1 sucks only the refrigerant from the injection extraction pipe 23 system. Therefore, a large amount of refrigerant can be circulated. Also, when liquid refrigerant is flowing to the low temperature side evaporator 8 side, gas refrigerant is used to flow to the high temperature side evaporator 6.
can continue to be pre-cooled, the cooling capacity of the high-temperature side evaporator 6 is increased overall. Therefore, the high temperature side evaporator 6 can be downsized.

(2) Since the refrigerant is forced to flow through the high-temperature side evaporator 6, the restriction on the positional relationship between the high-temperature side evaporator 6 and the gas-liquid separator 5, which was a conventional drawback, is also resolved. Therefore, in the narrow space inside the refrigerator-freezer,
Suitable for storing these items.

(3) The imbalance in the amount of refrigerant flowing through the high-temperature side evaporator 6 and the low-temperature side evaporator 8 is also eliminated. That is,
When the load on one of the evaporators decreases, the first and second electromagnetic on-off valves 28 and 27 are switched by detecting the temperature inside the freezing chamber, and the liquid refrigerant flows to the evaporator with a large load, so that it flows into the compressor 1. There is no liquid return. Further, when the load on both evaporators is reduced, the compressor 1 is stopped as in the conventional refrigeration cycle, so there is no liquid return in this case as well.

(4) Since the freezing and refrigerating compartments are alternately and continuously cooled, the operating time of the compressor 1 becomes longer.
As a result, the number of intermittent cycles is reduced by 1/2 compared to the conventional method, which prevents high-temperature refrigerant from flowing back from the suction port 11 toward the low-temperature side evaporator 8 immediately after the compressor stops, increasing the evaporator temperature and reducing the cooling capacity. can be reduced.

(5) Also, since the refrigerant is alternately circulated through the low-temperature side evaporator 8 and the high-temperature side evaporator 6, the compressor 1
The amount of displacement can be matched to the amount of refrigerant circulation required for the low-temperature side evaporator 8, which has a large load.
The displacement amount can be significantly smaller than the conventional displacement amount.

(6) As mentioned above, since the amount of work of the compressor 1 is small and the operating time is long, the abnormal noises made when the compressor 1 starts and stops becomes smaller, and the number of times you hear it is reduced.

(7) Since the liquid refrigerant in the low-temperature side evaporator 8 of the freezer compartment can be sucked out by the compressor 1 and defrosting can be performed while cooling the high-temperature side evaporator 6, efficient defrosting can be performed.

(8) Depending on the ambient temperature conditions in summer and winter, the low-temperature side evaporator 8 can be cooled by selecting either the main refrigeration cycle or the injection refrigeration cycle via the low-temperature side evaporator, especially in winter. When the suction pressure decreases and the input increases, it is possible to switch to the injection refrigeration cycle via the low-temperature side evaporator and perform low input operation, which together with (4) and (5) above result in significant savings. Brings power effect.

As explained in detail above, according to the present invention, the heat transfer coefficient of the high-temperature side evaporator is improved, and the restriction on the positional relationship between the high-temperature side evaporator and the gas-liquid separator is eliminated, thereby reducing the size of the refrigerator-freezer. By improving the unbalance of refrigerant flow between the high-temperature side evaporator and the low-temperature side evaporator, liquid returns to the compressor are prevented, and the refrigeration cycle is configured to adapt to changes in heat load due to ambient temperature. This makes it possible to provide a refrigerator-freezer that achieves significant power savings.

[Brief explanation of the drawing]

Fig. 1 is a cycle configuration diagram of a two-temperature evaporative refrigerator-freezer using a conventional multi-effect cycle, Fig. 2 is a Mollier diagram of a multi-effect cycle, and Fig. 3 is a diagram of an embodiment of the present invention. FIG. 4 is a cycle diagram of a refrigerator-freezer according to another embodiment of the present invention. 1... Compressor, 3... Condenser, 4... First throttle, 5...
Gas-liquid separator, 5b...Gas side outlet, 5c...Liquid side outlet, 6...High temperature side evaporator, 7...Second throttle, 8...Low temperature side evaporator, 11...Suction port, 25...Injection port, 27 ...Second electromagnetic on-off valve, 28...First electromagnetic on-off valve, 29...Gas outlet pipe, 31...Diversion pipe, 32...First electromagnetic on-off three-way valve, 33...Third electromagnetic on-off valve, 34...Fourth electromagnetic on-off valve , 36...Diversion pipe, 37...Second electromagnetic opening/closing three-way valve.

Claims (1)

[Claims] 1. A two-temperature evaporator that is connected sequentially from the discharge port of the compressor to a condenser, a first throttle, and a gas-liquid separator, and is equipped with a high-temperature side evaporator, a second throttle, and a low-temperature side evaporator. In the type refrigerator-freezer, a gas outlet pipe is provided to connect the gas side outlet of the gas-liquid separator and the inlet of the high-temperature side evaporator.
The outlet side of the high-temperature side evaporator is connected to the injection exit port of the compressor, and the liquid-side outlet of the gas-liquid separator is provided with a valve portion that allows flow to only one side and the other side, and one of the valve portions is connected to the high-temperature side evaporator. The inlet of the evaporator is connected to the second throttle, the outlet of the second throttle is connected to the inlet of the low-temperature evaporator, and the outlet of the low-temperature evaporator is provided with a valve that allows flow to only one side and only to the other. and one of which is connected to the suction port of the compressor,
A refrigerator-freezer characterized in that the other end is connected to an injection port of the compressor. 2. The refrigerator-freezer according to claim 1, wherein both of the valve portions that flow only to one side and the valve portions that flow only to the other side are constituted by one branch pipe and two electromagnetic on-off valves. 3. The refrigerator-freezer according to claim 1, wherein both of the valve portions that allow flow only to one side and only to the other side are electromagnetic opening/closing three-way valves.