General Electric Company

William J McCarty

Walter J Pohl

Bruce L Ruark

Frederick E Hicks

Russell L McCreary

Disclosed are apparatus and methods for controlling the defrosting of the outdoor heat exchange coil of a heat pump. In general, the disclosed apparatus and methods use the differencee between the outdoor heat exchanger and the outdoor ambient temperature to determine when to initiate a defrosting operation. Only a single sensor is employed, this single sensor being positioned at least proximate the outdoor heat exchanger such that the sensor responds to ambient temperature when the heat pump is first started and the heat exchanger is free of frost, and such that the sensnor becomes surrounded with frost as frost builds up on the heat exchanger during operation. At the beginning of a run the sensor is employed to read the ambient temperature, which is memorized. As frost builds, the sensor begins to reflect the temperature of the heat exchanger as the sensor becomes increasingly insulated by the frost from the surrounding air. During operation thereafter, the sensor is periodically read, the difference between the prevailing sensor temperature and the stored reference is determined and compared to an established difference reference, and a defrosting operation is initiated if the comparison difference exceeds the difference reference. The single sensor is also employed to determine when to terminate a defrosting operation, and also to determine whether to operate the outdoor fan as an aid to a defrosting operation.

Single-sensor head pump defrost control system

A refrigerator comprising side-by-side freezer and fresh food storage compartments cooled to their respective low and high operating temperatures by the circulation of streams of below-freezing air thereto includes a storage chamber in the fresh food compartment door maintained at an intermediate temperature by conducting air from the freezer compartment through the chamber.

Intermediate temperature storage chamber

A heat pump system comprising a compressor and two heat exchangers connected in a refrigerating circuit is provided with refrigerant flow restricting means between the heat exchangers which imparts relatively high restriction to the flow of refrigerant between the heat exchangers in one direction and a relatively lower restriction to the flow of refrigerant between the heat exchangers in the opposite direction.

Sonic restrictor means for a heat pump system

The present invention relates to a self-contained air conditioning unit and more particularly to a control system having a plurality of sensing means wherein a frost monitoring control is initiated in combination with the outdoor fan in a selected outdoor heat exchanger surface temperature and outdoor ambient temperature range and frost present on the surface of the outdoor heat exchanger, and a second stage defrost initiated in combination with an auxiliary heater at a below preselected temperature.

Air conditioning heat pump system having an initial frost monitoring

The present invention provides a system for effectively managing the refrigerant charge in a heat pump, and for separating a gaseous refrigerant from liquid refrigerant and oil mixture in a manner that allows oil entrapped with the refrigerant to transfer to the compressor, and to insure that only refrigerant in gaseous phase is allowed to enter the compressor through the suction line.

Refrigerant storage system for a heat pump

A refrigeration system for use in an air valve heat pump including a modulating restriction means and method of controlling the level of liquid in the system condenser. The restriction means includes a pair of capillary tubes in series flow arrangement and a sonic restrictor connected at one end to the inlet of the downstream capillary tube and at its other end at a point on the condenser where refrigeration in liquid state is required.

Refrigeration system modulating means

A room air conditioner of the air valve heat pump type wherein a solid state narrow differential thermal sensor is arranged on a heat exchange baffle that senses room ambient. The sensor is insulated to eliminate biasing the sensor with outdoor and component heat transfer. The sensor through the baffle follows room ambients and is cooled when the cooling cycle is terminated by cold air from evaporator located above the baffle and when the heating cycle is terminated the sensor is heated as warm air from the condenser located below the baffle rises over the baffle to raise the temperature of the sensor to prevent short cycling of the air conditioner on either the cooling or heating mode.

Room air conditioner sensor application

A reverse air cycle type heat pump is provided that utilizes a refrigeration system having a unidirection refrigerant flow wherein the condenser and evaporator retain their functions, but the air directed across them is redirected for different operations. The refrigeration system employed in the air cycle type heat pump is further provided with a secondary defrost circuit that includes the system liquid line and a conduit having a valve which permits refrigerant flow to bypass the compressor upon termination of compressor operation. A sensing means associated with the system expansion device is arranged on the suction line in a manner that allows the expansion device to regulate the flow of refrigerant through the liquid line in the normal manner when the compressor is operating, while allowing unrestrictive refrigerant flow through the liquid line when compressor operation terminates and the system pressure differential is equalized. This defrost circuit causes the relatively warm refrigerant in gaseous phase in the condenser to displace the relatively cold refrigerant in liquid phase in the evaporator with the flow continuing until the defrost process is completed.

Gravity defrost

A reverse air cycle type heat pump is provided that utilizes a refrigeration system having a unidirection refrigerant flow wherein the condenser and evaporator retain their functions, but the air directed across them is redirected for different operations. The refrigeration system is provided with a secondary defrost circuit including a first conduit between the upper portion of the evaporator and the compressor casing and a second conduit having a valve which permits refrigerant flow to by-pass the expansion device only when compresssor operation terminates and the system pressure differential is equalized. This defrost circuit causes the relatively warm refrigerant in gaseous phase in the compressor to displace the relatively cold refrigerant in liquid phase in the evaporator with the flow continuing until the defrost process is completed.

Refrigeration system gravity defrost

The present invention relates to a heat pump that utilizes unidirection refrigerant flow wherein the condenser and evaporator retain their functions, but the air directed across them is redirected for different operations. While the heat pump is operating in the cooling mode, outdoor air is passed in heat exchange relationship with the condenser for liquefying the refrigerant and outside again; and indoor air is passed in heat exchange relationship with the evaporator for cooling the air circulated again. Conversely, in the heating mode, outdoor air passed in heat exchange relationship with the evaporator for vaporizing the refrigerant, then outside again; and indoor air is passed in heat exchange relationship with the condenser for heating the air and circulated again.

Air valve heat pump

The present invention relates to a heat pump that utilizes unidirection refrigerant flow wherein the condenser and evaporator retain their functions, but the air directed across them is redirected for different operations. While the heat pump is operating in the cooling mode, air dampers are positioned so that outdoor air is passed in heat exchange relationship with the condenser for liquefying the refrigerant and outside again; and indoor air is passed in heat exchange relationship with the evaporator for cooling the air circulated again. Conversely, in the heating mode, the air dampers are positioned so that outdoor air passed in heat exchange relationship with the evaporator for vaporizing the refrigerant, then outside again; and indoor air is passed in heat exchange relationship with the condenser for heating the air and circulated again.

A reverse air cycle type heat pump is provided that utilizes unidirection refrigerant flow wherein the condenser and evaporator retain their functions, but the air directed across them is redirected for different operations. The air cycle type heat pump is further provided with a secondary defrost circuit including valves which permit refrigerant flow to by-pass the compressor and the expansion device only when compressor operation terminates and the system pressure differential is equalized. This defrost circuit causes the relatively warm refrigerant in gaseous phase in the condenser to displace the relatively cold refrigerant in liquid phase in the evaporator with the flow continuing until the defrost system is completed.

Self-contained heating and cooling apparatus

The present invention relates to a defrost arrangement for refrigeration systems and in the preferred embodiment to reverse cycle, heat pump refrigeration systems. A secondary defrost circuit is provided including valves which permit refrigerant flow to by-pass the compressor and the expansion device only when compressor operation terminates and the system pressure differential is equalized. The refrigerant flow in the secondary circuits allows refrigerant to flow between the upper portions and lower portions of the indoor and outdoor heat exchangers. This free non-restrictive flow of refrigerant causes the relatively warm refrigerant in gaseous phase when present in the condenser to displace the relatively cold refrigerant in liquid phase when present in the evaporator, with the flow continuing until the system equalizes.

Heat pump defrost system

In a self-contained air conditioner unit of the reversible type having cooling and heating cycles, a no-drain heat pump is provided wherein in the cooling cycle condensate water collected on the indoor heat exchanger operating as an evaporator is transferred to the outdoor section of the unit where it is atomized and directed through the relatively warm outdoor heat exchanger operating as a condenser. In the heating cycle, water collected on the outdoor heat exchanger operating as an evaporator during heating is transferred to the indoor section. The condensate is directed into the air flow circulating through the indoor section where it atomizes and passes through the relatively warm indoor heat exchanger to humidify the air.

Air conditioning apparatus

The present invention relates to a reversible refrigeration system providing a combination of cooling the hermetic motor of the system during the cooling cycle of the system by injecting a portion of refrigerant from the system into the discharge flow of the compressor and storing portion of the refrigerant during the heating cycle.

Growing community of inventors

Louisville, KY, United States of America

William J McCarty