JPS62206344A - Air conditioner and operation method thereof - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The invention disclosed herein relates generally to refrigeration technology, and more particularly, to a method for initiating an operating cycle of a refrigeration system to minimize cycle losses caused by unsteady state operation. Relating to systems and methods.

As energy costs increase, there is a growing desire for efficient heating and cooling systems of all types and sizes. Heat pumps have rapidly become popular primarily due to their efficiency compared to traditional heating systems. Compressors used in heat pumps,
The efficiency of heat pumps themselves has also been improved in the past, primarily by improving the efficiency of the fans and motors. Larger coils are used in new heat pumps to improve seasonal performance by increasing steady-state operating efficiency.

During steady-state operation of an air conditioning system, approximately 65-85% of the refrigerant charge is located on the high pressure side of the system, and during long downtimes a large amount of refrigerant moves to the evaporator, which is generally It is at a lower room temperature than the condenser. At the start of the next operating cycle, excess refrigerant from the low pressure side of the system must be pumped to the high pressure side of the system to provide steady-state operation; the liquid refrigerant in the evaporator flows to the accumulator and suction The pressure drops to a value low enough to vaporize the liquid and the compressor sends the vapor to the condenser. This process can take several minutes and during this time the air conditioning system is not operating at steady state capacity; the larger the coil dimensions of the system, the greater the amount of refrigerant in such a system, resulting in cycle losses in the system. also becomes larger. -Tactically in heat pumps,
The time required to deliver coolant from the evaporator to the condenser for steady state operation is 6 minutes or more.

Similar problems occur during the defrost cycle of a heat pump, both at the beginning and end of the defrost cycle and at the beginning of heating mode operation. When the cycle is reversed, both at the beginning or at the end of the defrost cycle, the coolant flows into the accumulator and is gradually boiled out of the accumulator for steady state operation. Therefore, the heating efficiency of the heat pump is reduced due to inefficiencies caused by improper positioning of the coolant when reversing the function of the heat exchanger at the beginning of the defrost cycle and at the beginning of heating mode operation. As a result of the cycle loss at the beginning of the defrost cycle, the time required for defrost is longer;
Both cycle losses also increase the amount of supplementary heat required.

Separating each coil from the solenoid valve substantially reduces coolant movement caused by temperature differences.

Although the normal cycle losses caused by coolant movement can be reduced in this way, there is no reduction in the cycle losses of the defrost cycle caused by the reversal of heat exchanger function and the resulting improper positioning of the coolant. Furthermore, as a result of the large pressure differential that occurs across the compressor during startup, such systems must include a hard start device. Therefore, even if cost is saved by reducing cycle loss, separate equipment is required when the coil is separated from the solenoid valve, which is generally undesirable.

SUMMARY OF THE INVENTION Accordingly, it is a principal object of the present invention to provide an air conditioning system and a method of operating the system in which steady-state operating conditions can be quickly achieved, thereby significantly reducing cycle losses caused by unsteady-state operation.

Another object of the present invention is to provide an air conditioning system and method of operating the system that eliminates accumulator overload and compensates for refrigerant movement without the need for a hard start device.

Yet another object of the present invention is to provide a heat pump that results in unsteady state operation caused by improper coolant position due to heat exchanger reversal both at the beginning of the defrost cycle and upon resuming normal heating operation mode. An object of the present invention is to provide a method of operating an air conditioner that significantly reduces cycle loss.

The above and other objects are achieved in the present invention by providing a dual flow expansion valve assembly in the cooling line between the heat exchangers of a conventional air conditioner.

A reversing valve is provided in the discharge line from the compressor and is adjusted to a position that directs the flow of refrigerant opposite the direction of the desired mode of operation at the beginning of a cycle. The process control valve assembly is opened to provide substantially unrestricted flow in the coolant line between the heat exchangers. The liquid refrigerant in the evaporator flows into the condenser, and the double-flow expansion valve is closed for metering.

Adjust the reversing valve to flow coolant in the correct direction for the desired mode of operation and begin normal operation.

In heat pumps, a dual-flow expansion valve is opened at the beginning of the defrost cycle to allow coolant to flow from the indoor coil to the outdoor coil. The reversing valve is then switched to defrost mode and the dual flow expansion valve assembly is adjusted to coolant metering to provide defrost.

Upon completion of the defrost cycle, the dual-flow expansion valve assembly is again opened to allow substantially unrestricted flow through the coolant line, flowing liquid coolant to the indoor coil;
Adjust the reversing valve to heating operation mode and close the dual flow expansion valve to coolant metering condition.

These and other objects of the invention will become apparent from the following detailed description and accompanying drawings.

Referring now to the drawings in more detail, reference numeral 10 designates a heat pump. This heat pump is of substantially conventional design, but has a dual flow expansion valve assembly 12 that enables the heat pump to operate according to the method of the present invention.

This dual-flow expansion valve assembly replaces the expansion device and check valve commonly found in the cooling line between the heat exchangers of a heat pump. The operation of the dual flow expansion valve assembly will now be described in more detail. The heat pump further includes a compressor 14, an indoor heat exchanger assembly 16, and an outdoor heat exchanger assembly 18.

An accumulator 20 is installed in the suction line 21 of the compressor.
However, if this method is used to operate the air conditioner, the accumulator can be eliminated.

The indoor heat exchanger assembly 16 includes a coolant-to-air heat exchange coil 22 and a fan 24, and is also provided with a backup electrical resistance heater. The outdoor heat exchanger assembly 18 includes a refrigerant-air heat exchange coil 2
8 and a fan 30. The indoor and outdoor heat exchanger assemblies are of conventional design and will not be described in further detail.

Reversing valve 32 is connected to the compressor discharge boat by a coolant line, to the compressor suction boat by suction line 21, and to coils 22 and 28 by lines 36 and 38, respectively. This reversing valve is also of conventional design and operates as a steamer, directing high pressure refrigerant vapor from the compressor to the outdoor coil during heating mode or defrost operation, and from the compressor to the outdoor coil during cooling operating mode. It is for returning coolant from the coil to the compressor.

A cooling line 4 is provided between the indoor coil 22 and the outdoor coil 28.
0 is located and a twin flow expansion valve assembly 12 is located within the cooling line. Dual-flow expansion valve assemblies include multiple disparate valve structures that cooperate in function or a single complex valve that allows flow to pass without restriction and metered flow in either direction. This assembly may include an indoor coil 22 as shown schematically.
and metering passages 42 and 44 for metering the coolant passing through the passages to and from the outdoor coil 28, respectively. A solenoid valve 46 or the like is disposed within line 40 such that when opened, the valve 46 allows coolant to flow unrestricted through line 40 and when closed, coolant flows only through metering orifice 42 or metering orifice 44. Let it pass. These orifices are connected to coolant line 40 by branch lines 48 and 50 that bypass the flow passage of the valve assembly including solenoid valve 46.

The operation of the heat pump according to the method of the invention in the state of the basic construction of the heat pump of the invention as fully described above will now be explained more fully in connection with each mode of operation.

At the beginning of the cooling mode cycle, the coolant is at the room temperature of the cooler in the indoor unit, so the indoor coil 22
It has moved to . For steady state operation,
Approximately 65-80% of the coolant should be on the high pressure side containing the outdoor coil 28.

To achieve this condition briefly at the beginning of the operating cycle, the dual flow expansion valve assembly 12 is adjusted to a flow passing condition with valve 46 open and coolant flow limited only to the capacity of line 40. The reversing valve 32 is adjusted to a position for heating mode operation in which high pressure refrigerant vapor is directed to the indoor coil 22. The compressor is started and the excess liquid refrigerant in the indoor coil is rapidly pumped through the twin flow expansion valve assembly to the outdoor coil. Once the liquid coolant is pumped out of the indoor coil (which only takes a few seconds), the dual-flow expansion valve assembly 12 is adjusted to a metering condition in which the flow passageway with valve 46 is closed. Adjust the reversing valve 32 to the appropriate position for the cooling mode of operation which directs the refrigerant vapor to the outdoor coil.

The reversal of the above method for cooling mode operation during heating mode of operation is as follows.

Excess liquid coolant is traveling to the outdoor coil, which is at a cooler ambient temperature than the indoor coil. At the beginning of the heating cycle, adjusting the reversing valve 32 to the cooling mode operating position;
The dual flow expansion valve assembly 12 is adjusted to an unrestricted flow condition with valve 46 fully open and the compressor flows refrigerant from the outdoor coil to the indoor coil. After this is completed, the dual flow expansion valve assembly is adjusted to the coolant metering condition with valve 46 closed. Adjust the reversing valve to the heating mode activation position and continue the conventional heating cycle. The coolant is present within the heat pump within seconds, eliminating the many minutes of unsteady state operation that often occur in conventional systems.

When a defrost cycle is required, first place the reversing valve in the heating mode operating position, then set the
If the reversing valve remains in the heating mode activation position, valve 4
6 is fully open, regulating the dual flow expansion valve assembly to an unrestricted flow condition where the compressor continues to operate and refrigerant from the indoor coil is rapidly pumped to the outdoor coil. Next, the process expansion assembly is adjusted to the coolant metering condition, the reversing valve 32 is adjusted to the defrost cooling mode operation condition, and
Then start the defrost cycle. At the completion of the defrost cycle, the reversing valve 32 remains in the cooling or defrost mode operating position and the dual flow expansion valve assembly 12 is adjusted to an unrestricted flow condition to rapidly pump liquid coolant from the outdoor coil to the indoor coil. Adjust the dual flow expansion valve assembly to the fluid metering position and the reversing valve to the heating mode operating position to complete the cycle.

By utilizing this method, considerable energy can be saved, especially during defrost mode. This eliminates many minutes of unsteady state operation both at the start of the defrost cycle and at the restart of the heat mode cycle. The defrost cycle is now more efficient, requiring less time to defrost and less back-up heat. Due to reduced cycle losses, the basic cooling and heating cycles are also more efficient, resulting in shorter on-cycle times and lower energy consumption.

The invention works equally well with cooling-only air conditioning systems. Such systems require the addition of a reversing valve and self-flow expansion assembly to the system.

At the beginning of each cooling cycle, the system operates as described above for the heat pump cooling cycle.

A dual flow expansion valve assembly can also be used to control the amount of superheat leaving the evaporator. A solid-state controller can be used to control the system at the beginning of the operating cycle, as well as to optimize the amount of superheat for the current operating conditions.

Thus, in addition to improving overall system efficiency by minimizing unsteady state time, the present apparatus can be used to improve steady state operation and further increase the efficiency of the air conditioning system.

Although the air conditioning system and its method of operation have been illustrated and described in detail above with particular reference to a heat pump system, various modifications may be made without departing from the scope of the invention.

[Brief explanation of drawings]

FIG. 1 is a schematic illustration of a heat pump having a dual flow expansion valve assembly operated in accordance with the method of the present invention. 12... Double flow expansion valve assembly, 14... Compressor, 16... Indoor heat exchanger assembly, 18... Outdoor heat exchanger assembly, 20... Accumulator, 22... Indoor coil, 28... ...Outdoor coil, 32...Reversing valve.

Claims (12)

[Claims] (1) A method for rapidly reaching steady-state operation of an air conditioner having a compressor, a condenser, and an evaporator, comprising: upon start-up: a) a substantially unrestricted flow path of refrigerant flow from the evaporator to the condenser; b) flowing refrigerant from the evaporator through a non-restrictive flow path to the condenser; c) forming a non-restrictive flow path for metering refrigerant from the condenser to the evaporator. A method consisting of 2. The method of claim 1, further comprising: (2) flowing the refrigerant by operating a compressor and directing compressed refrigerant vapor to an evaporator. (3) forming a substantially unrestricted flow path for refrigerant flow from the condenser to the evaporator; b) refrigerant flow from the condenser to the evaporator; c) refrigerant flow from the evaporator to the condenser; d) operating a compressor to direct compressed refrigerant vapor from the compressor to an evaporator to defrost the evaporator; e) (i) (ii) providing a non-restrictive flow path for refrigerant flow from the evaporator to the condenser; (ii) providing refrigerant flow from the evaporator to the condenser; (iii) directing refrigerant flow from the condenser to the evaporator; A method according to claim 1, comprising repeating the step of forming a non-restrictive flow path for metering. (4) performing the step of flowing the coolant by operating a compressor, directing refrigerant vapor from the compressor to one of the condenser and the evaporator, and flowing the coolant therefrom; Method. (5) refrigerant lines disposed between the compressor, the evaporator, the condenser, between the compressor and the condenser, between the evaporator and the compressor, and between the evaporator and the condenser, and between the evaporator and the condenser; a first valve means disposed in a refrigerant line between the evaporator and the condenser, said valve means allowing refrigerant to flow through said valve means substantially unrestricted by the valve means between the evaporator and the condenser; It has a flow passing portion that is open and a metering portion that is restricted when the valve means is in a condition to meter the refrigerant flow between the condenser and the evaporator, and further has a metering portion that is open to allow the flow to flow between the condenser and the evaporator. A method for operating an air conditioner comprising a reversing valve having first and second operating states for directing refrigerant vapor to a vessel, comprising: a) placing the first valve means in a flow passing operating state; b) refrigerant. adjusting a reversing valve to direct vapor from the compressor to the evaporator; c) operating the compressor to pump excess liquid refrigerant from the evaporator through a flow passage portion of the first valve means to the condenser; d) an air conditioner comprising the steps of: placing a first valve means in a restricted operating state to meter refrigerant flow from the condenser to the evaporator; e) adjusting a reversing valve to direct refrigerant vapor from the compressor to the condenser; how to drive. (6) a) placing the first valve means in a flow-through operation while maintaining the reversing valve in a condition to pump refrigerant vapor to the condenser; b) pumping excess liquid refrigerant from the condenser to the evaporator; c) placing a first valve means in a flow metering condition for metering the flow of refrigerant from the evaporator to the condenser; d) directing refrigerant vapor from the compressor to the evaporator and defrosting the evaporator. e) adjusting the reversing valve to permit unrestricted flow of refrigerant from the evaporator to the condenser while maintaining the reversing valve in a condition to pump refrigerant vapor to the evaporator; f) pumping excess liquid refrigerant from the evaporator to the condenser; g) returning the first valve means to non-restrictive operation; metering the flow of refrigerant from the condenser to the evaporator; 6. The method of claim 5, further comprising: h) repositioning a reversing valve to direct refrigerant vapor from the compressor to the condenser. (7) an indoor and outdoor heat exchanger and a compressor that alternately function as an evaporator and a condenser during cooling and heating modes, respectively; a refrigerant line disposed between the heat exchanger and the compressor; The operating mode directs the refrigerant from the compressor to the outdoor heat exchanger and
a reversing valve having respective first and second positions directing refrigerant from the compressor to the indoor heat exchanger in an operating mode and metering refrigerant flow in either direction between the heat exchanger and the heat exchanger; A method of operating a heat pump having a dual-flow expansion valve assembly forming a substantially unrestricted flow of refrigerant through a refrigerant line between: a) a heat exchanger that functions as an evaporator during a desired mode of operation; placing a reversing valve in a position to direct refrigerant vapor; b) adjusting the twin flow expansion valve assembly to permit substantially unrestricted flow of refrigerant between the heat exchangers; c) d) operating a compressor to flow liquid refrigerant from a heat exchanger acting as an evaporator during a desired mode of operation to a heat exchanger acting as a condenser during a desired mode of operation; d) cooling between the heat exchangers; heat pump operation consisting of placing a dual-flow expansion valve in position to meter the flow of refrigerant; e) placing a reversing valve in position to direct the refrigerant vapor to a heat exchanger that functions as a condenser during the desired mode of operation; Method. (8) With the indoor heat exchanger functioning as a condenser and the outdoor heat exchanger functioning as an evaporator, the heat pump is
operating in a mode of operation, a) regulating the twin flow expansion valve assembly to pass flow in an unrestricted manner from the indoor heat exchanger to the outdoor heat exchanger while maintaining the reversing valve in a second mode of operation; b) twin flow; c) flowing refrigerant from the indoor heat exchanger to the outdoor heat exchanger through the expansion valve assembly; c) placing the reversing valve in a first mode of operation and metering the coolant flow from the outdoor heat exchanger to the indoor heat exchanger; d) operating a compressor to defrost the outdoor heat exchanger; e) cooling from the outdoor heat exchanger to the indoor heat exchanger while maintaining the reversing valve in a first operating mode; f) flowing refrigerant from the outdoor heat exchanger to the indoor heat exchanger through the twin flow expansion valve assembly; g) adjusting the reversing valve to the indoor heat exchanger; 8. The method of claim 7, further comprising the step of returning the twin flow expansion valve assembly to the two mode of operation and metering coolant flow from the indoor heat exchanger to the outdoor heat exchanger. (9) refrigerant lines disposed between the evaporator, the condenser, the compressor, between the compressor and the evaporator, between the compressor and the condenser, and between the evaporator and the condenser; A method of defrosting a heat pump having a restriction means for metering the flow of refrigerant in the flow path from the condenser to the evaporator, comprising: a) not restricting the flow of refrigerant in the flow path from the condenser to the evaporator; b) by flowing liquid refrigerant from the condenser to the evaporator; c) by restricting the flow of refrigerant in the flow path from the evaporator to the condenser; and d) by directing refrigerant vapor from the compressor to the evaporator. , operating the heat pump in conventional defrost mode; e) not restricting the flow of refrigerant in the flow path from the evaporator to the condenser; f) flowing the refrigerant from the evaporator to the condenser; g) from the condenser. A heat pump defrosting method consisting of the successive steps of: restricting the flow of refrigerant in the flow path to the evaporator; h) resuming operation of a conventional heat pump. (10) first and second heat exchangers, one of which operates as an evaporator and the other as a condenser, a compressor, and a refrigerant disposed between the heat exchanger and between the compressor and the heat exchanger. an air conditioner having a line and a reversing valve for directing refrigerant from a compressor to any of said heat exchangers, said heat exchanger acting as an evaporator to said heat exchanger acting as a condenser; air conditioner including means for briefly activating upon start-up to cause the air to flow. (11) the coolant flow means includes a twin-flow expansion valve assembly disposed in a coolant line between the first heat exchanger and the second heat exchanger, the twin-flow expansion valve assembly disposed in the coolant line between the first heat exchanger and the second heat exchanger; a first through-flow path for metering the flow of coolant between the first heat exchanger and the second heat exchanger;
Claim 1 having a second through flow passage allowing coolant to flow between the heat exchanger and the second heat exchanger.
The air conditioner described in item 0. (12) A method for rapidly reaching steady state operation of a heat pump system having a low pressure section and a high pressure section, comprising: a) a substantially unrestricted flow of refrigerant from the low pressure section of the system to the high pressure section of the system; b) flowing refrigerant from said low pressure part of the system to said high pressure part of the system; c) restricted to meter the flow of refrigerant from said high pressure part of the system to said low pressure part of the system; A method that includes, at startup, a continuous step of forming a flow path.