JPH08303882A - Method of operating heat pump using new alternative refrigerant gas hfc - Google Patents

Abstract

PURPOSE: To achieve operations of cooling, refrigerating and freezing using a heat pump into which an alternative refrigerant gas HFC(fluorocarbon containing hydrogen) is injected singly or in a mixture. CONSTITUTION: An air-cooled condenser 2A is provided with an air-cooled condenser 2B additionally and the condensing temperature of a refrigerant is set to a low temperature within the atmospheric temperature plus 5 deg.C to perform an operation. A water-cooled condenser 2C1 is provided with a water- cooled condenser 2C2 additionally and the condensing temperature of the refrigerant gas is set to a low temperature, by 1 deg.C or higher than the temperature of cooling water being sent to the water-cooled condenser.

Description

Detailed Description of the Invention

[0001]

INDUSTRIAL APPLICABILITY The present invention enables the operation of a heat pump by using a new alternative refrigerant gas HFC (fluorocarbon containing hydrogen) in place of a refrigerant gas such as a specific CFC CFC and an alternative CFC HCFC. A method for operating a heat pump. It seems that a method of operating a cooler, a refrigerator, etc., using HFC134a as a refrigerant gas has already been established, but in order to further improve efficiency, the temperature inside the refrigerator to be cooled is -20 ° C.
The present invention provides an operation method suitable for cooling to the following low temperatures. In such a case, the HFC-based refrigerant gas can be used alone, but the non-flammable HFC134a
(CH ₂ FCF ₃ ) and HFC125 (CHF ₂ CF ₃ ).
The present invention provides a method for operating a heat pump, in which the operating pressure is adjusted to the operating pressure of the heat pump currently in use, and the structure of the equipment is not significantly changed.

[0002]

2. Description of the Related Art Nowadays, chlorofluorocarbon is almost completely abolished, and the newly developed new alternative refrigerant gas has a boiling point of minus 26.3 ° C. and is used for cooling and fridges.
FC134a and HFC125, which has a boiling point of minus 48.5 ° C and has been developed for refrigerators, are promising, but when these refrigerant gases are used by replacing them with the currently used air conditioner or refrigerator. , It usually does not work properly. The reason for this is that, unlike CFC and HCFC-based CFCs currently used, HFC-based refrigerant gas does not contain chlorine, so it is not compatible with mineral-based lubricating oil,
Refrigerant gas and oil are separated during the operation of the heat pump,
It is said that the cause is that the oil does not return to the compressor together with the refrigerant gas, causing the compressor to burn. Further, it is said that when the heat pump is operated with the HFC-based refrigerant gas for a long time, the refrigerant gas becomes high in temperature and operation becomes impossible.

Therefore, development of an ester oil compatible with HFC type refrigerant gas and research of a mixed refrigerant containing a refrigerant gas which is flammable but has a good compatibility with oil are under way. HCFC22 used for cooling
The HFC three-type mixed gas as an alternative and the HFC three-type mixed gas as an alternative to R502 used for a refrigerator are all mixed with a flammable refrigerant gas. HFC1 for cooling the freezer to -20 ° C or below
No. 25 can not operate alone, HFC125, HFC1
It seems that 43a and HFC134a ternary mixed refrigerant gas does not operate normally even if they are put into the currently used refrigerator.

[0004]

DISCLOSURE OF THE INVENTION The present invention provides a refrigerating operation for cooling and refrigerating an inside of a refrigerator to 5 ° C. or less while performing cooling and refrigerating operations by using HFC type refrigerant gas alone or in combination. This makes it possible to normally perform the refrigerating operation of cooling the inside of the refrigerator to -20 ° C or lower. Also,
Even when the HFC refrigerant gas is mixed and the operating pressure is set to a desired value, only the non-flammable refrigerant gas is mixed and put into the heat pump, which enables normal operation. .

[0005]

The present invention will be described with reference to the drawings. In FIG. 1, an air-cooled condenser is used. The compressor 1, the air-cooled condenser 2A and the expansion valve 3 are connected by a high pressure gas pipe 5, and the expansion valve 3, the evaporator 4 and the compressor 1 are connected by a low pressure gas pipe 6. An air-cooled condenser 2B is additionally provided on the heat pump, and the air-cooled condenser 2A, the air-cooled condenser 2B, and the expansion valve 3 are connected by a high-pressure gas pipe 7, and the air-cooled condenser 2 is connected.
A, the high pressure gas pipe 5 between the expansion valve 3 is eliminated. In this case, even if the high-pressure gas pipe 5 between the air-cooling condenser 2A and the expansion valve 3 is cut and the air-cooling condenser 2B is additionally installed, the high-pressure gas pipe 5 between the compressor 1 and the air-cooling condenser 2A is cut and air-cooling is performed between them. The condenser 2B may be additionally provided. In the operation of the heat pump using the current air-cooled condenser, the condensation temperature of the refrigerant gas that exits the air-cooled condenser and enters the expansion valve is the atmospheric temperature sent to the air-cooled condenser plus 15 ° C. The refrigerant gas that has undergone heat exchange is sent to the air-cooled condenser 2B and exchanges heat with the atmosphere again to increase the amount of heat released and lower the temperature.
The temperature of the condensed refrigerant gas exiting B and entering the expansion valve is set within the atmospheric temperature sent to the air-cooled condenser plus 5 ° C.

In the operation of the current heat pump, the refrigerant gas discharged from the air-cooled condenser is in a bubble state when viewed with a liquid level gauge. However, since the CFC and HCFC type Freon gas contains chlorine, the refrigerant gas and the oil. Are fully compatible. Since the HFC refrigerant gas does not contain chlorine, the refrigerant gas and oil are not compatible with each other in the condensation in the bubble state, but after heat exchange with the atmosphere in the air cooling condenser 2A, heat is exchanged with the atmosphere in the air cooling condenser 2B. By exchanging, the refrigerant gas releases all heat release calories to the atmosphere,
The temperature of the refrigerant gas discharged from the air-cooled condenser 2B drops to within 5 ° C of the atmospheric temperature sent to the air-cooled condenser 2B. When the calorie release is exhausted in this way, the refrigerant gas is completely liquefied and has no bubbles, and the refrigerant gas and the oil are sufficiently compatible with each other. That is, since the amount of heat released by the air-cooled condenser is large and the refrigerant gas is completely liquefied, the temperature of the refrigerant gas becomes high and becomes saturated even when the heat pump is operated for a long time using the HFC refrigerant gas. There is no such thing. Refrigerant gas is easily separated from oil when it evaporates at a low temperature. Therefore, it is necessary to completely liquefy it so that it is compatible with oil and evaporate at a low temperature to make the inside of the chamber minus 20 °
This is particularly important in the operation of a refrigerator that cools to C or lower.

The one shown in FIG. 2 uses a water-cooled condenser, and the compressor 1, the water-cooled condenser 2C1 and the expansion valve 3 are connected by a high pressure gas pipe 5, and the expansion valve 3, the evaporator 4 and the compressor 1 are connected by a low pressure gas pipe 6. A water-cooled condenser 2C2 is added to the heat pump connected by. The water-cooled condenser 2C1, the additionally installed water-cooled condenser 2C2, and the expansion valve 3 are connected by a high-pressure gas pipe 7, and the high-pressure gas pipe 5 between the water-cooled condenser 2C1 and the expansion valve 3 is eliminated. When doing this,
Even if the high-pressure gas pipe 5 between the water-cooled condenser 2C1 and the expansion valve 3 is cut and the water-cooled condenser 2C2 is additionally installed between them, the high-pressure gas pipe between the compressor 1 and the water-cooled condenser 2C1 is cut, and the water-cooled condenser 2 is inserted between them.
C2 may be added. Then, the water cooler 8 such as a cooling tower and a radiator is installed, and the water cooler 8 and the water cooling condenser 2C are connected to the water pipe 10 via the water pump 9.
1. The water cooling condenser 2C2 is reciprocally connected so that the cooling water circulates between the water cooler 8 and the water cooling condenser 2C1 and the water cooling condenser 2C2. Water-cooled condenser 2
The refrigerant gas that has exchanged heat with the cooling water in C1 has a temperature of plus 10 ° C. of the temperature of the cooling water sent to the water-cooled condenser. The refrigerant gas discharged from the water-cooled condenser 2C1 is sent to the water-cooled condenser 2C2, exchanges heat with the cooling water again, and releases all heat radiated calories to the cooling water to lower the temperature of the refrigerant gas. The refrigerant gas condensing temperature that exits the water cooling condenser 2C2 and is sent to the expansion valve 3 is set to be 1 ° C or more lower than the cooling water temperature that is sent to the water cooling condenser 2C2.

At first glance, it seems irrational that the temperature of the refrigerant gas discharged from the water-cooled condenser 2C2 is lower than that of the cooling water before the heat exchange, but the heat exchange with the cooling water was performed by the ordinary water-cooled condenser 2C1. After that, when it enters the additional water-cooled condenser 2C2 and exchanges heat with the cooling water again, it is more efficient to exchange heat with the cooling water than to exchange heat with the refrigerant gas. The gas is completely liquefied and the volume is reduced,
The liquefied gas flows in the vacuum pipe, and a gap of the liquefied gas is created in the pipe, which lowers the temperature of the gas pipe surface. Thus, when completely liquefied, the refrigerant gas and the oil are well compatible with each other, and the refrigerant gas and the oil are not separated even if the heat pump is operated using the HFC refrigerant gas. With the large amount of heat released by the water-cooled condenser,
By completely liquefying, even if the heat pump is operated for a long time using the HFC-based refrigerant gas, the temperature of the refrigerant gas does not rise and the gas is saturated. Refrigerant gas easily separates from oil when evaporated at a low temperature, so it is necessary to completely liquefy it to improve compatibility with oil when operating a refrigerator that evaporates at a low temperature and cools the inside of the refrigerator to -20 ° C or lower. Is especially important.

Here, the air-cooled condenser 2A is additionally provided with the air-cooled condenser 2B, that is, the air-cooled condenser 2B may be additionally provided with the air-cooled condenser 2A of the current heat pump, or the air-cooled condenser 2A, the air-cooled condenser 2B. It also means that it may be replaced with a single unit having the combined capabilities. In addition, when a new heat pump is manufactured, it includes the case where a single unit having a combined capability of the air-cooled condenser 2A and the air-cooled condenser 2B is installed. In this way, when a single unit having the combined ability of the air-cooled condenser 2A and the air-cooled condenser 2B is installed, the portion where the refrigerant gas condensation temperature of the current air-cooled condenser is up to the ambient temperature plus 15 ° C is equivalent to the air-cooled condenser 2A. However, from the point where the refrigerant gas temperature becomes lower than that, it corresponds to the air-cooled condenser 2B.

The water-cooled condenser 2C1 is additionally provided with the water-cooled condenser 2C2, which means that the water-cooled condenser 2C2 may be additionally provided with the water-cooled condenser 2C1 of the current heat pump.
It means that the water-cooled condenser 2C2 may be replaced with a single unit having a combined capability. Also,
Even when a new heat pump using a water-cooled condenser is manufactured, the water-cooled condenser 2C1 and the water-cooled condenser 2 are used.
There may be a plurality of C2s, and this includes the case of installing a single unit having a combined capacity of the water-cooled condenser 2C1 and the water-cooled condenser 2C2. The condensing temperature of the refrigerant gas of the heat pump using the current water-cooled condenser is set to plus 10 ° C with the atmospheric temperature. Therefore, the operation of the summer cooler is 43 ° C condensation. The cooling water in the cooling tower was cooled to the same temperature as the atmospheric temperature by the wet bulb temperature and sent to the water-cooled condenser. Therefore, the ambient temperature and the temperature of the cooling water sent to the water-cooled condenser are about the same. In this way, when a single unit with the combined capacity of the water-cooled condenser 2C1 and the water-cooled condenser 2C2 is installed, the condensing temperature of the refrigerant gas of the current water-cooled condenser, the temperature of the cooling water sent to the water-cooled condenser plus 10 ° C Corresponds to the water-cooled condenser 2C1, and from the point where the refrigerant gas temperature becomes lower than that, it corresponds to the water-cooled condenser 2C2.

As described above, the condensation temperature of the refrigerant gas is the atmospheric temperature plus 5 ° C. when the air-cooled condenser is used.
In the case of using a water-cooled condenser, by operating the heat pump at a temperature lower than the temperature of the cooling water sent to the water-cooled condenser by 1 ° C or more, the compatibility of the refrigerant gas and the oil is improved, and the HFC-based refrigerant with good low-temperature characteristics. When gas is used, even if the evaporation temperature in the evaporator is set to a temperature lower than -40 ° C, the gas is always completely evaporated without being separated from the oil.

Here, the condensing temperature of the refrigerant gas means the surface temperature of the gas pipe that exits the condenser and reaches the expansion valve.

When a water-cooled condenser 2C2 is added to the air-cooled condenser 2A, or when the water-cooled condenser 2C is used.
When the air-cooled condenser 2B is additionally provided in C1, if one is an air-cooled condenser, it can be handled as a condition when using the air-cooled condenser.

When the condensing temperature of the refrigerant gas is lowered and the refrigerant gas is completely liquefied to operate the heat pump using the capillary tube as described above, the refrigerant gas has no bubbles, so that the refrigerant gas in the small diameter hole of the capillary tube is removed. And the evaporation pressure and evaporation temperature in the evaporator increase. In the cooling operation at high temperature, there is no problem even if the evaporation pressure and the temperature become high, and the cooling capacity of the cooler is improved by increasing the flow rate of the refrigerant gas, so that it can be used as it is.

When the cooler is operating normally, but the temperature of the refrigerant gas entering the compressor is not higher than 5 ° C., the amount of refrigerant gas passing through the capillary tube is large and the heat absorbing ability of the refrigerant gas remains. So the capacity of the evaporator is 1
When it is increased by 0% or more, the heat absorption amount of the cooler is further increased.

Refrigeration for cooling the interior to plus 5 ° C or lower,
In the freezing operation, if the refrigerant gas is completely liquefied in a bubble-free state, the flow rate of the liquefied gas in the small diameter hole of the capillary tube increases. When using an expansion valve to adjust the flow rate of the refrigerant gas, the flow rate of the refrigerant gas is reduced in accordance with the temperature of the inside of the refrigerator to be cooled, so the refrigerant gas evaporation temperature gradually decreases, and the inside of the refrigerator becomes low temperature over time. become. If only a capillary tube having a small diameter hole through which the refrigerant gas passes is used, if the amount of the refrigerant gas sent to the evaporator increases, the temperature of the refrigerant evaporates at a high temperature and the inside of the refrigerator cannot be cooled. In such a case, the inner diameter of the capillary tube is made smaller than the conventional one by 0.1 mm or more. In this case, the capillaries may be replaced, or one having a smaller inner diameter of 0.1 mm or more may be connected to the existing capillaries. Also, the length of the capillary tube may be doubled to increase the resistance and reduce the flow rate.
Furthermore, reducing the diameter of the capillary tube,
It can also be combined with doubling the length to adjust the refrigerant gas flow rate. When using the refrigerator in the high temperature room, a flow rate control valve may be attached to control the flow rate of the refrigerant gas.

When the condensing temperature of the refrigerant gas discharged from the air-cooled condenser is set to a temperature lower than the atmospheric temperature plus 5 ° C. and completely liquefied to operate the cooler, the refrigerant gas is used even in a high temperature place. Is not saturated. In the summer, the operating pressure is 20 kg / cm ² even if the vehicle is stopped in a high temperature place using the HFC134a in a vehicle cooler.
Since it is not higher than a certain level and the refrigerant gas is not saturated, cooling operation is always possible and it is safe. It is also possible to operate the cab cooler in a hot place and the refrigerator in a hot room.

As described above, when the condensing temperature of the refrigerant gas is lowered to complete liquefaction, the compatibility of the refrigerant gas and the oil is improved, and HFC-based refrigerant gases HFC134a and HF are used.
The heat pump can be operated regardless of whether C125 or the like is mixed and used alone. In the cooling and refrigerating operation, the HFC134a and the inside of the refrigerator are set to 2
0. HFC12 for operation of a freezer that cools to a low temperature below C
5 can be used alone.

Further, the operating pressure of the heat pump can be lowered by lowering the condensing temperature of the refrigerant gas. Generally, a refrigerant gas having a low boiling point has a high operating pressure, and thus is not suitable for cooling and refrigerating operations, but it can be used when the operating pressure is low. Further, since the refrigerant gas having a low boiling point has a low evaporation temperature even if the evaporation pressure is increased, if the flow rate of the refrigerant gas sent to the evaporator is increased and the evaporation pressure is increased, the power value used by the compressor decreases, It saves energy. According to the present invention, HFC125 having a boiling point of −48.5 ° C. can be used alone to perform cooling and refrigerating operations.

It is of course possible to operate the heat pump by mixing various HFC type refrigerant gases. Refrigerant operation CFC substitute refrigerant gas, HFC125, HFC1
It operates normally for a long time in a refrigerating operation in which the inside of the refrigerator is cooled to -25 ° C or lower by using a mixed gas of three kinds of 43a and HFC134a.

If the compatibility between the refrigerant gas and the oil is sufficient, the compatibility with the oil is good, but it is not necessary to mix the flammable refrigerant gas. Non-flammable HFC134a and H
The distribution with FC 125 can be varied and mixed to achieve the required operating pressure. For example, (1) HFC134a 30% or less HFC125 70% or more (2) HFC134a 40% or less HFC125 60% or more (3) HFC134a 50% or less HFC125 50% or more (4) HFC134a 60% or less HFC125 40% or more (5) HFC134a 70 % Or less HFC125 30% or more (6) HFC134a 80% or less HFC125 20% or more Various compounds can be blended to obtain a desired operating pressure and evaporation temperature. As an alternative to the HCFC22, (3),
The mixing ratio of (4) is similar in operating pressure and evaporation temperature. Refrigerant gas that is a mixture of two types of HFC134a and HFC125 leaks from HFC134a, which is a gas with a high boiling point and light when a gas leak occurs, so only HFC134a needs to be replenished when a gas leak occurs, and it is necessary to replace the entire amount of the refrigerant gas. There is no.

[0022]

A method of improving a heat pump using the air-cooled condenser shown in FIG. 1 will be described. The currently used CFC is collected from the current heat pump consisting of the compressor 1, the air-cooled condenser 2A, the expansion valve 3 and the evaporator 4, and the air-cooled condenser 2B is additionally installed. Calculate the releasable ability. Normally, it is necessary to add about 50% to 100% of the capacity of the air-cooled condenser currently used. However, the capacity of this volume may differ depending on the temperature and the air volume of the atmosphere for heat exchange. When an air-cooled condenser 2B is additionally installed between the compressor 1 and the air-cooled condenser 2A, the compressor 1, the air-cooled condenser 2B, the air-cooled condenser 2A and the expansion valve 3 are connected by a high pressure gas pipe. At this time, the order of the air-cooled condenser 2B and the air-cooled condenser 2A may be the order of the air-cooled condenser 2A and the air-cooled condenser 2B. When the air-cooled condenser 2B is additionally provided between the air-cooled condenser 2A and the expansion valve 3, the compressor 1, the air-cooled condenser 2A, the air-cooled condenser 2B and the expansion valve 3 are connected by a high pressure gas pipe. Next, the HFC-based refrigerant gas is introduced. Since the refrigerant gas is completely liquefied and the volume is reduced because the condenser is doubled, the amount of the fluorocarbon gas injected is about twice the conventional amount. inject.

When the heat pump is operated in this way, the refrigerant gas compressed by the compressor 1 and discharged at high pressure and high temperature is sent to the air-cooling condenser 2A to exchange heat with the atmosphere to radiate heat, and to condense half to form bubbles. It becomes a state. The temperature of the refrigerant gas discharged from the air cooling condenser 2A is about the atmospheric temperature sent to the air cooling condenser 2A plus about 15 ° C. The refrigerant gas that has exchanged heat with the atmosphere in the air-cooled condenser 2A is sent to the air-cooled condenser 2B and exchanges heat with the atmosphere again, so that the heat radiation calorie of the refrigerant gas disappears.
The condensing temperature of the refrigerant gas that has left the air-cooled condenser 2B drops to within the atmospheric temperature sent to the air-cooled condenser plus 5 ° C. When the heat release calorie is exhausted, the refrigerant gas is completely liquefied and is in a bubble-free state, so that it is well compatible with oil, and even if the heat pump is operated using the HFC refrigerant gas, the refrigerant gas becomes No oil separation occurs.

A method of improving the heat pump using the water-cooled condenser shown in FIG. 2 will be described. The currently used CFC is collected from the current heat pump consisting of the compressor 1, the water-cooled condenser 2C1, the expansion valve 3 and the evaporator 4, and the water-cooled condenser 2C2 is additionally installed. Calculate the releasable ability. Generally, it is necessary to add about 50% to 100% of the capacity of the air-cooled condenser currently used. In this case as well, the temperature may vary depending on the temperature and amount of the cooling water to be heat-exchanged. When a water cooling condenser 2C2 is additionally installed between the compressor 1 and the water cooling condenser 2C1, the compressor 1 and the water cooling condenser 2C
2. Connect the water cooling condenser 2C1 and the expansion valve 3 with a gas pipe. At this time, the order of the water-cooled condenser 2C2 and the water-cooled condenser 2C1 may be the order of the water-cooled condenser 2C1 and the water-cooled condenser 2C2. When the water cooling condenser 2C2 is additionally installed between the water cooling condenser 2C1 and the expansion valve 3, the compressor 1, the water cooling condenser 2
C1, the water cooling condenser 2C2 and the expansion valve 3 are connected by a high pressure gas pipe. For the cooling water circuit, the water pipe 10 after the water pump 9 is divided into two water cooling condensers 2C1,
Connect with water-cooled condenser 2C2, water-cooled condenser 2
The water pipes from the C1 and the water cooling condenser 2C2 are merged, or a plurality of water pipes are combined and returned to the water cooler 8 such as a cooling tower or a radiator. Next, the HFC-based refrigerant gas is injected, but since the condenser is doubled and the refrigerant gas is completely liquefied and the volume is reduced, it is about twice the amount of the conventional CFC gas injection. Inject.

The heat pump is operated in this way. The HFC refrigerant gas compressed by the compressor 1 and discharged at high pressure and high temperature is sent to the water cooling condenser 2C1 to exchange heat with the cooling water. It radiates heat and becomes a semi-liquefied foam. At this time, water-cooled condenser 2C1
The temperature of the refrigerant gas exiting from is the temperature of the cooling water entering the water cooling condenser 2C1 plus about 10 ° C. The refrigerant gas that has exchanged heat with the cooling water in the water-cooled condenser 2C1 is sent to the water-cooled condenser 2C2 and again exchanges heat with the cooling water of the same temperature sent to the water-cooled condenser 2C1 to radiate all the calories radiated by the refrigerant gas. Then, it was completely liquefied, and when observed with a liquid level gauge attached after the water-cooled condenser 2C2, there was no bubble. When the liquid gas is completely liquefied in this way, the volume of the refrigerant gas is reduced, a gap is created in the vacuum pipe, and the temperature of the gas pipe surface is lowered.The refrigerant gas condensation temperature measured at the surface of the gas pipe is sent to the water-cooled condenser. The phenomenon occurs that the temperature becomes 1 ° C or more lower than the temperature of water. Conventionally, even HFC refrigerant gas, which is said to be incompatible with oil in normal operation, is sufficiently compatible with oil when the condensation temperature is lowered and completely liquefied. Driving is possible.

It is generally said that the HFC type refrigerant gas is likely to cause a problem at a low temperature. Further, the HFC-based refrigerant gas easily absorbs water and seems to freeze at low temperatures. Therefore, it is necessary to lower the refrigerant gas condensation temperature to the limit. Lowering the condensing temperature of the refrigerant gas by using an air-cooled condenser within 5 ° C of the ambient temperature and a water-cooled condenser of 1 ° C or more lower than the cooling water temperature is effective in normal cooling operation, but This is a critical requirement for the operation of a refrigerator that cools the inside to plus 5 ° C or less, especially the operation of a freezer that cools the inside to minus 20 ° C or less.

As described above, when the refrigerant gas is completely liquefied to eliminate bubbles, the refrigerant gas flow rate in the small-diameter hole of the capillary tube increases, so that the evaporation density in the evaporator increases and the evaporation pressure and the evaporation temperature increase. Becomes higher. In a cooling operation with a high atmospheric temperature for cooling, the performance of the cooler improves as the evaporation temperature rises, but in the refrigeration operation, the flow rate of the refrigerant gas is higher than that of the conventional freon gas that was operated in the condensation of bubbles. Therefore, the evaporation temperature rises by about 5 ° C and the inside of the refrigerator cannot be cooled to the required temperature. Replace the inner diameter of the capillary tube with a smaller one by 0.1 mm or
By connecting those having a size of mm or more, the length is doubled to increase the resistance as necessary, the flow rate of the refrigerant gas is reduced, and the evaporation temperature is lowered. In particular, when the refrigerator is used in a high temperature room, the operating pressure increases and the refrigerant gas flow rate increases, so the refrigerant gas flow rate is adjusted by the control valve.

As described above, even when the HFC refrigerant gas is completely liquefied by lowering the condensation temperature, the refrigerant gas and the oil are well compatible with each other, and the operation of the heat pump can be performed without any trouble. Therefore, the compatibility with the oil is good. However, it is not necessary to mix the flammable refrigerant gas. Current flammable HFC3
2, 3 non-flammable HFC125, non-flammable HFC134a mixed gas is tried, but non-flammable HFC12
5. Incombustible HFC134a can be mixed and used so as to have a desired operating pressure.

When the refrigerant gas condensing temperature is lowered to complete liquefaction, the refrigerant gas is not saturated and the operating pressure does not increase.
A refrigerant gas having a low boiling point can be used for cooling and refrigerating operations. For example, HFC with a boiling point of minus 48.5 ° C
When 125 is used, even if a large amount of refrigerant gas is sent to the evaporator and the evaporation pressure increases, the evaporation temperature does not increase, so that the heat absorption efficiency of the heat pump is improved.

[0030]

[Embodiment] The following shows an operating state of a freezer in which the temperature inside the case is set to a low temperature of -25 ° C or lower. The air-cooled condenser 2B is installed after the air-cooled condenser 2A, and the refrigerant gas exchanges heat with the atmosphere in the air-cooled condenser 2A, and then is sent to the air-cooled condenser 2B and exchanges heat with the atmosphere again to lower the condensation temperature and reduce the temperature of the refrigerator. I drove. Refrigerant gas is HFC125 44%, HFC143a 5
It is a mixed gas of 2% and 4% of HFC134a.

The operating state of the refrigerator is shown. (1) Refrigerant gas high pressure 11.2 kg / cm ² (2) Refrigerant gas low pressure 0.4 kg / cm ² (3) Compressor discharge gas temperature 29.8 ° C (4) Air-cooled condenser 2B discharge gas temperature 15.9 ° C (5) Air temperature with air-cooled condenser 13.2 ° C (6) Gas temperature with compressor 0.5 ° C (7) Temperature in freezer minus 27.5 ° C

The condensation temperature of the refrigerant gas discharged from the air-cooled condenser 2B is the atmospheric temperature plus 2.7 ° C. In the freezer,
It is kept at minus 27.5 ° C, minus 35 °
It was possible to cool to C. The refrigerator is operating normally for a long time in both summer and winter, but is operating normally.

The operation state of a commercial refrigerator using the refrigerant gas HFC134a is shown. The currently used CFC gas R12 is recovered, an air-cooled condenser 2B is added to the existing air-cooled condenser 2A, and a refrigerant gas HFC134a that is twice the amount of the injected CFC gas R12 is charged.
After exchanging heat with the air in the air-cooled condenser 2A, it was sent to the air-cooled condenser 2B and exchanged heat with the atmosphere again to lower the condensation temperature to operate.

The operation state of a commercial refrigerator having a compressor capacity of 180 W is shown. (1) Refrigerant gas high pressure 5.8 kg / cm ² (2) Refrigerant gas low pressure 0.4 kg / cm ² (3) Compressor discharge gas temperature 34.2 ° C (4) Air-cooled condenser 2B discharge gas temperature 17.2 ° C (5) Air temperature with air-cooled condenser 14.9 ° C (6) Gas temperature with compressor 3.2 ° C (7) Refrigerator temperature minus 12.5 ° C

The condensation temperature of the refrigerant gas discharged from the air-cooled condenser 2B is as low as the atmospheric temperature plus 2.3 ° C. The inside of the refrigerator is cooled to -12.5 ° C, and it functions well as a refrigerator. In this refrigerator, minus one
It was possible to cool to 8 ° C.

The operating state of the cooler using HFC134a as the refrigerant gas and using a water-cooled condenser is shown below. From a conventional cooler using a water-cooled condenser operated by a refrigerant gas HCFC22, a refrigerant gas HCFC2
2 is collected, a water cooling condenser 2C2 is additionally installed after the existing water cooling condenser 2C1, and the cooling water circuit is connected to a water cooler 8 such as a cooling tower or a radiator. The water pipe 10 coming out of the water pump 9 is divided into two and sent to the water-cooling condenser 2C1 and the water-cooling condenser 2C2 in the same amount, and the cooling water coming out of the water-cooling condenser 2C1 and the water-cooling condenser 2C2 is combined to cool the cooling tower, radiator, etc. Return to vessel 8, water cooler 8 and water-cooled condenser 2
Cooling water was circulated between C1 and the water-cooled condenser 2C2. The refrigerant gas that has exchanged heat with the cooling water in the water-cooled condenser 2C1 is sent to the water-cooled condenser 2C2,
The heat was exchanged again with the cooling water having the same temperature as that sent to the water-cooled condenser 2C1. The cooler was 5 HP, and the cooling water heated by the water-cooled condenser was cooled by the cooling tower to the same temperature as the atmospheric temperature. The refrigerant gas HFC134a is the same as the conventional refrigerant gas HCFC22.
The cooler was operated by injecting double the amount.

The operating state of a cooler using this 5 HP water-cooled condenser is shown. (1) Atmospheric temperature 30.5 ° C (2) Refrigerant gas high pressure 9.1 kg / cm ² (3) Refrigerant gas low pressure 2.0 kg / cm ² (4) Compressor discharge gas temperature 72.5 ° C (5) Water cooling Condenser 2C1 outlet gas temperature 36.2 ° C (6) Water-cooled condenser 2C2 outlet gas temperature 28.5 ° C (7) Cooling water temperature with water-cooled condenser 30.5 ° C (8) Water-cooled condenser 2C1, water-cooled condenser 2C2 outlet Combined temperature of the cooling water of 34.7 ° C (9) Atmosphere temperature entering the evaporator 25.6 ° C (10) Atmosphere temperature at the outlet of the evaporator 15.1 ° C (11) Atmosphere temperature sucked in and discharged from the evaporator 10. 5 ° C

From the water temperature of the water-cooled condenser, the condensation temperature of the refrigerant gas discharged from the additional water-cooled condenser 2C2 is 2 °.
The reversal phenomenon of low C is occurring. The atmospheric temperature difference between the intake and the outlet of the evaporator is 10.5 ° C, which is almost the same as when the HCFC22 is used as the refrigerant gas. Refrigerant gas HFC134a is HCFC2
The condensing pressure is 68% compared to 2, and the refrigerant gas does not sufficiently pass through the expansion valve and the capillary tube that match the operating pressure of the HCFC 22, and the required amount of refrigerant gas cannot be sent to the evaporator. Further, the refrigerant gas HFC134a is
Since the molecular weight is smaller than that of the refrigerant gas HCFC22,
Since the capacity of the refrigerant is 61% with the same amount of refrigerant, the refrigerant gas HFC134a is generally considered to be unusable as a substitute for the refrigerant gas HCFC22. However, in the operation of this cooler, the condensation temperature of the refrigerant gas is lowered to completely liquefy and eliminate bubbles, so that the expansion valve,
The amount of refrigerant gas that passes through the capillary tube is about 1.6 times as much, and the refrigerant gas that completely radiates heat in the condenser and is liquefied without any bubbles improves the evaporation state in the evaporator, so the performance of the cooler is improved. Did not decline.

An embodiment of a commercial refrigerator having a compressor capacity of 180 W will be described. The Freon gas CFC12 enclosed in this refrigerator is collected, and the air-cooled condenser 2
An air-cooled condenser 2B is added to A, and H is used as a refrigerant gas.
FC134a was injected about twice as much as CFC12 was injected, and when the existing state of the capillary tube with an inner diameter of 0.8 mm was operated at room temperature of 25 ° C, the evaporation pressure of the refrigerant gas was 1.1 kg. / Cm ² and the inside cannot be lowered to plus 3 ° C or lower. This is because the refrigerant gas is completely liquefied and bubbles are eliminated, the amount of refrigerant gas passing through the capillary tube is large, and the evaporation pressure and the evaporation temperature are high. So, if you use a capillary tube with an inner diameter of 0.1 mm and a small diameter of 0.7 mm, the evaporation pressure drops to 0.4 kg / cm ² and the inside of the refrigerator drops to -12.5 ° C. It was activated and made ice.

The refrigerator described above is kept at a room temperature of 43 ° C. and a humidity of 80.
%, The evaporation pressure is 0.9 kg / cm ²
The inside of the refrigerator does not fall below -3 ° C. Therefore, double the length of the capillary tube to 30
At 0 mm, the evaporation pressure was 0.6 kg / cm ² and the inside of the refrigerator was -8 ° C. When a flow rate control valve was attached to this refrigerator and the evaporation pressure was 0.4 kg / cm ² , the inside of the refrigerator could be lowered to -12.5 ° C.

Even if a non-flammable HFC refrigerant gas is used, the cooling temperature of the refrigerant gas is kept within the ambient temperature plus 5 ° C by the air cooling condenser, and the condensation temperature is sent to the water cooling condenser when the water cooling condenser is used. When the temperature is lower than the water temperature by 1 ° C or more, the refrigerant gas is completely liquefied and the compatibility with the oil is improved, the refrigerant gas flow rate to be sent to the evaporator is reduced, and the refrigerant is evaporated at a low temperature. Refrigerating and freezing operations are possible. As described above, according to the present invention, a non-combustible refrigerant gas, for example, H
FC134a, HFC125, etc. could be used alone. In addition, HFC134a and HFC125
Can be mixed to operate the heat pump at a desired operating pressure.

[0042]

According to the present invention, it is possible to perform a refrigerating operation in which the inside of the refrigerator is cooled to -20 ° C or less by using the HFC type refrigerant gas. Also, using HFC134a,
It becomes possible to perform cooling and refrigerating operation with the current equipment and the current oil that use HCFC22, CFC12, etc. as the refrigerant gas. Further, it has good compatibility with oil, but does not use a flammable refrigerant gas, and uses an incombustible HFC-based refrigerant gas alone or in combination to enable operation of an existing heat pump. is there.

[Brief description of drawings]

[Figure 1] Air-cooled condenser 2A to air-cooled condenser 2B
Is installed, and the condensing temperature of the refrigerant gas is the atmospheric temperature plus 5 ° C.
2 is a schematic configuration diagram of a heat pump that is set to a low temperature within the range and operates using an HFC-based refrigerant gas.

[Figure 2] Water-cooled condenser 2C1 to water-cooled condenser 2
It is a schematic configuration diagram of a heat pump in which C2 is additionally provided, the condensation temperature of the refrigerant gas is set to 1 ° C. or more lower than the water temperature sent to the water-cooled condenser, and the HFC refrigerant gas is used for operation.

[Explanation of symbols]

 1 ・ ・ ・ Compressor 2A ‥‥‥ Existing air-cooled condenser 2B ‥‥‥ Additional air-cooled condenser 2C1 ‥ ‥ Existing water-cooled condenser 2C2 ‥ ‥ Additional water-cooled condenser 3 ‥‥‥‥‥‥ Evaporator 5 ‥‥‥ ‥‥‥ Existing high pressure gas pipe 6 ‥‥‥‥ Low pressure gas pipe 7 ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥ Cooling tower, radiator, etc. Water cooler 9 ‥‥‥‥‥ Water pump 10 ‥‥‥‥‥

Claims (4)

[Claims] 1. A compressor 1 and an air-cooled condenser 2
A, expansion valve 3 (including a capillary tube), evaporator 4
In a heat pump having an air-cooled condenser 2B
Is added to increase the heat dissipation capacity of the refrigerant gas, and the condensing temperature of the refrigerant gas that exits the air cooling condenser and enters the expansion valve 3 is set within the atmospheric temperature plus 5 ° C. entering the air cooling condenser. , A method of operating a heat pump using a new alternative refrigerant gas HFC (fluorocarbon containing hydrogen). 2. A compressor 1 and a water-cooled condenser 2
In a heat pump having C1, expansion valve 3 (including a capillary tube), and evaporator 4, a water-cooled condenser 2
C2 is additionally installed to increase the heat dissipation capacity of the refrigerant gas, and the condensation temperature of the refrigerant gas that exits the water cooling condenser and enters the expansion valve 3 is set to 1 from the temperature of the cooling water sent by the water pump 9 and entering the water cooling condenser. A method of operating a heat pump using a new alternative refrigerant gas HFC (fluorocarbon containing hydrogen), which is characterized in that the temperature is set to a temperature of ° C or higher. 3. A heat pump having a compressor, a condenser, a capillary tube, and an evaporator, which cools the inside of a refrigerator to a low temperature of plus 5 ° C. or less, and the inner diameter of the capillary tube is the same as that of a conventional machine. A method for operating a heat pump using a new alternative refrigerant gas HFC (fluorocarbon containing hydrogen), characterized by having a diameter of 0.1 mm or more smaller than that used. 4. A heat pump comprising a compressor, a condenser, an expansion valve (including a capillary tube) and an evaporator, wherein HFC (fluorocarbon containing hydrogen) 134a (CH ₂ FCF ₃ ) and HFC (fluorocarbon containing hydrogen) are used. ) 125 (CHF ₂ CF ₃ ) non-flammable refrigerant gas is mixed and used,
A method of operating a heat pump using a new alternative refrigerant gas HFC (fluorocarbon containing hydrogen).