Apparatus and method for checking conditioning mode of a heat pump system

Abstract

An apparatus for checking conditioning mode of a heat pump system includes: (a) a temperature sensing device coupled with the heat pump system at a sensing locus; (b) a comparing device coupled with the temperature sensing device and configured for comparing a first temperature sensed by the temperature sensing device at a first time with a second temperature sensed by the temperature sensing device at a second time to determine an extant conditioning mode; the extant conditioning mode being a first conditioning mode when the second temperature is greater than the first temperature; the extant conditioning mode being a second conditioning mode when the second temperature is less than the first temperature.

Description

BACKGROUND OF THE INVENTION

The present invention is directed to heat pump systems, and especially to assuring proper operation of heat pump systems as directed by control devices.

A heat pump system is essentially an air conditioning system that can be operated in reverse. When it is desired that a conditioned indoor space be cooled, a reversing valve is oriented in a first position to cause refrigerant fluid to flow in a first direction. When refrigerant flows in the first direction, an indoor coil operates as an evaporator, picking up heat from the conditioned space and removing it to an outdoor coil. The outdoor coil operates as a condenser, losing heat to the atmosphere outside the conditioned space. When it is desired that the conditioned space be heated, the reversing valve is oriented in a second position to cause the refrigerant to flow in a second direction. When the refrigerant flows in the second direction, the indoor coil operates as a condenser, losing heat to the conditioned space. The outdoor coil operates as an evaporator, picking up heat from the atmosphere and providing the heat to the indoor conditioned space.

Movement of the reversing valve between the first position and the second position may be effected by any of several mechanisms. Magnetic attraction to a first position or a second position is one common moving mechanism. Other mechanisms may include, by way of example and not by way of limitation, electrical solenoids, levers, bimetal expansion elements, and similar mechanisms for moving the reversing valve between its first and second positions.

There is a problem in operating the reversing valve in that the valve sometimes becomes stuck. The valve typically becomes stuck in its first position or in its second position, but may become stuck in an interim position between its first and second positions. Whenever the reversing valve is not in a proper position for effecting the operation ordered by a control device, the heat pump system operates incorrectly or inefficiently. For example, if a control device orders a heat pump system to operate in a conditioning mode appropriate to cool a space and the reversing valve does not move to the proper position to effect cooling operations, the heat pump system may actually be heating the space instead of performing the ordered cooling operation. Similarly, if a control device orders a heat pump system to operate in a conditioning mode appropriate to heat a space and the reversing valve does not move to the proper position to effect heating operations, the heat pump system may actually be cooling the space instead of performing the ordered heating operation.

There is a need for an apparatus and method for checking conditioning mode of a heat pump system.

There is a need for an apparatus and method for checking conditioning mode of a heat pump system that can automatically cease operation of the heat pump system when the heat pump system is detected as being in a conditioning mode other than an ordered conditioning mode.

SUMMARY OF THE INVENTION

An apparatus for checking conditioning mode of a heat pump system includes: (a) a temperature sensing device coupled with the heat pump system at a sensing locus; (b) a comparing device coupled with the temperature sensing device and configured for comparing a first temperature sensed by the temperature sensing device at a first time with a second temperature sensed by the temperature sensing device at a second time to determine an extant conditioning mode; the extant conditioning mode being a first conditioning mode when the second temperature is greater than the first temperature; the extant conditioning mode being a second conditioning mode when the second temperature is less than the first temperature.

A method for checking conditioning mode of a heat pump system includes the steps of: (a) in no particular order: (1) providing a temperature sensing device coupled with the heat pump system at a sensing locus; and (2) providing a comparing device coupled with the temperature sensing device; and (b) sensing a first temperature by the temperature sensing device at a first time; (c) sensing a second temperature by the temperature sensing device at a second time; (d) comparing the first temperature with the second temperature to determine an extant conditioning mode; (e) if the second temperature is greater than the first temperature then the extant conditioning mode is a first conditioning mode; and (f) if the second temperature is less than the first temperature then the extant conditioning mode is a second conditioning mode.

The method may include the further step of: (g) if the comparing indicates that the extant conditioning mode is not an ordered conditioning mode established by the heat pump system, ceasing operation of the heat pump system.

It is therefore an object of the present invention to provide an apparatus and method for checking conditioning mode of a heat pump system.

It is a further object of the present invention to provide an apparatus and method for checking conditioning mode of a heat pump system that can automatically cease operation of the heat pump system when the heat pump system is detected as being in a conditioning mode other than an ordered conditioning mode.

Further objects and features of the present invention will be apparent from the following specification and claims when considered in connection with the accompanying drawings, in which like elements are labeled using like reference numerals in the various figures, illustrating the preferred embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of a representative heat pump system employing the apparatus of the present invention.

FIG. 2 is a flow diagram illustrating the method of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 is a schematic diagram of a representative heat pump system employing the apparatus of the present invention. In FIG. 1, a heat pump system 10 is installed for conditioning an interior or inside space 12. A compressor 14 is situated in an exterior or outside space 17 outside a wall 18. An interior or inside coil 20 is situated in interior space 12. Interior coil 12 is in fluid communication with an exterior or outside coil 22 and with compressor 14 in a fluid network involving a reversing valve 24. Exterior coil 22 and reversing valve 24 are situated in exterior space 16. A blower unit 26 urges air across interior coil 20 in a direction indicated by an arrow 28. A blower unit 30 urges air across exterior coil 22 in a direction indicated by an arrow 32.

Heat pump system 10 also includes a thermostat unit 34 and a defrost unit 36 coupled with a control unit 38. Control unit 38 is also coupled with compressor 14 and with reversing valve 24.

Reversing valve 24 has a common input port 40, a common output port 42 and bidirectional ports 44, 46. A directing element 48 is situated inside reversing valve 24. Directing element 48 may be situated in a first position spanning common output port 42 and bidirectional port 44 (indicated by a solid line) or in a second position spanning common output port 42 and bidirectional port 46 (indicated by a dotted line). Details regarding how directing element 48 is moved are not illustrated in FIG. 1.

During cooling operations when heat pump system 10 operates to cool interior space 12, directing element 48 is in its right-hand (dotted line) position in FIG. 1. In this configuration, refrigerant is exhausted from compressor exhaust 13 and enters reversing valve at common input port 40. Because directing element 48 is in its right-hand position bidirectional port 44 is left unmasked and refrigerant exits reversing valve 24 via port 44. Refrigerant exits via port 44 and enters exterior coil 22 in a compressed vapor state. In the cooling operation, exterior coil 22 operates as a condenser and interior coil 20 operates as an evaporator so that as refrigerant traverses exterior coil 22 it is cooled and condenses to a liquid. Air flowing over exterior coil 22 because of blower unit 30 removes heat from refrigerant in exterior coil 22. Liquid refrigerant enters interior coil 20 where it is heated by air forced over interior coil 20 by blower unit 26. In this manner refrigerant in interior coil 20 picks up heat from interior space 12 thereby cooling interior space 12. Refrigerant exits interior coil 20 in a vapor state and enters reversing valve 24 via bidirectional port 46. Because directional element 48 is in a position spanning bidirectional port 46 and output port 42, refrigerant entering reversing valve 24 via bidirectional port 46 is directed to exit reversing valve 24 via output port 42. Thereafter refrigerant in its vapor state returns to compressor 14 via an intake port 15.

During heating operations when heat pump system 10 operates to heat interior space 12, directing element 48 is in its left-hand (solid line) position in FIG. 1. In this configuration, refrigerant is exhausted from compressor exhaust 13 and enters reversing valve at common input port 40. Because directing element 48 is in its left-hand position bidirectional port 46 is left unmasked and refrigerant exits reversing valve 24 via port 46. Refrigerant exits via port 46 and enters interior coil 20 in a compressed vapor state. In the heating operation, interior coil 20 operates as a condenser and exterior coil 22 operates as an evaporator so that as refrigerant traverses interior coil 20 it is cooled and condenses to a liquid. Air flowing over interior coil 20 because of blower unit 26 picks up heat given up by refrigerant in interior coil 20 as the refrigerant condenses and cools. It is this heat that warms interior space 12. Liquid refrigerant enters exterior coil 22 from interior coil 20. In exterior coil 22 refrigerant is heated by air forced over exterior coil 22 by blower unit 30. In this manner refrigerant in exterior coil 22 picks up heat from exterior space 16 thereby returning refrigerant in exterior coil 22 to a vapor state. Refrigerant exits exterior coil 22 in a vapor state and enters reversing valve 24 via bidirectional port 44. Because directional element 48 is in a position spanning bidirectional port 44 and output port 42, refrigerant entering reversing valve 24 via bidirectional port 44 is directed to exit reversing valve 24 via output port 42. Thereafter refrigerant in its vapor state returns to compressor 14 via an intake port 15.

One may observe that there are characteristic loci within heat pump system 10 that exhibit temperatures related to the operation being performed by heat pump system 10. That is, when heat pump system 10 is performing a cooling operation, temperatures at certain loci in heat pump system 10 will be relatively cool and other loci in heat pump system 10 will be relatively warm. By way of example and not by way of limitation, during cooling operations, heat pump system 10 will exhibit cool temperatures at port 23 of exterior coil 22, at port 19 of interior coil 20 and at bidirectional port 46 of reversing valve 24. Providing a temperature sensing device at one or more such characteristic loci permits one to check whether heat pump system 10 is actually performing a cooling operation. An illustration of placing a temperature sensing device according to the present invention is provided by placing a temperature sensing device 50 at bidirectional port 46. Temperature sensing device 50 is coupled with control unit 38. This capability is particularly useful in situations where, by way of example and not by way of limitation, control unit 38 (or another control input) orders heat pump system 10 to cool interior space 12 but directional element 48 malfunctions, such as by sticking or otherwise not completely moving to its proper location for cooling operations. In such circumstances, heat pump system 10 could be performing a heating operation in spite of its having been ordered to perform a cooling operation.

By way of further example and not by way of limitation, during heating operations, heat pump system 10 will exhibit warm temperatures at port 23 of exterior coil 22, at port 19 of interior coil 20 and at bidirectional port 44 of reversing valve 24. Providing a temperature sensing device at one or more such characteristic loci permits one to check whether heat pump system 10 is actually performing a heating operation. This capability is particularly useful in situations where, by way of example and not by way of limitation, control unit 38 (or another control input) orders heat pump system 10 to heat interior space 12 but directional element 48 malfunctions, such as by sticking or otherwise not completely moving to its proper location for heating operations. In such circumstances, heat pump system 10 could be performing a cooling operation in spite of its having been ordered to perform a heating operation.

Eventually an occupant of interior space 12 may notice that heat pump system 10 is not performing an ordered operation—heating or cooling. However it would be better if heat pump system 10 could itself note incorrect performance. It would be particularly advantageous if heat pump system 10 could take action, such as ceasing operation, as by shutting down compressor 14, in the event of noting incorrect performance. Most heat pump systems have an installed defrost control unit, such as defrost unit 36. Defrost units are typically configured for deciding when to cease compressor operation in response to predetermined system conditions. The system conditions that may occasion a compressor shut down vary from system to system. A capability to respond to certain circumstances of incorrect performance that may be noted by the present invention can be programmed into an existing defrost control unit 36, thereby giving heat pump system 10 a capability to respond to noted occasions of incorrect performance without having to provide an additional new feedback unit for implementing a compressor shut down. Simply reprogramming a defrost control device such as defrost control unit 36 to accommodate effecting shut down on the occurrence of additional circumstances (e.g., incorrect performance other than ordered performance) is an economical implementation of the preferred embodiment of the present invention. In such an embodiment, temperature sensing device 50 may be coupled directly with defrost unit 36 (not shown in FIG. 1).

Noting incorrect performance may be effected using a comparing device, preferably located in control unit 38 or in defrost unit 36, to compare temperature sensed by a temperature sensing device at a characteristic locus (an extant temperature) with an expected temperature that should occur if heat pump system 10 is properly performing the ordered operation. Improper performance may alternately be performed on a time-of-performance bases. Thus, by way of example and not by way of limitation, if a temperature sensing device is placed for detecting temperature of exterior coil 22 (or another appropriately situated characteristic locus) one may compare temperature of exterior coil 22 at a steady state condition without compressor 14 operating with temperature of exterior coil 22 at a steady state condition while compressor 14 is operating. If the off-compressor temperature is greater than the running compressor temperature, then it can be surmised that the unit is operating in a heating mode. If, in contrast, the off-compressor temperature is less than the running compressor temperature, then it can be surmised that the unit is operating in a cooling mode.

FIG. 2 is a flow diagram illustrating the method of the present invention. In FIG. 2, a method 100 for checking conditioning mode of a heat pump system begins at a START locus 102. Method 100 continues with the step of, in no particular order: (1) providing a temperature sensing device coupled with the heat pump system at a sensing locus, as indicated by a block 104; and (2) providing a comparing device coupled with the temperature sensing device, as indicated by a block 106.

Method 100 continues with the step of sensing a first temperature by the temperature sensing device at a first time, as indicated by a block 108. Method 100 continues with the step of sensing a second temperature by the temperature sensing device at a second time, as indicated by a block 110. Method 100 continues with the step of comparing the first temperature with the second temperature to determine an extant conditioning mode, as indicated by a block 112. Method 100 continues with the step of determining whether the second temperature is greater than the first temperature, as indicated by a query block 114. If the second temperature is greater than the first temperature, then method 100 continues via YES response line 116 and the extant conditioning mode is a first conditioning mode, as indicated by a block 118. If the second temperature is less than the first temperature, then method 100 continues via NO response line 120 and the extant conditioning mode is a second conditioning mode, as indicated by a block 122.

Method 100 may (the verb “may” being indicated by a dotted line) continue with the step of determining whether the extant conditioning mode is an ordered conditioning mode established by the heat pump system, as indicated by a query block 124. If the extant conditioning mode is an ordered conditioning mode, then method 100 continues via YES response line 126 to a locus 128, and method 100 continues thereafter executing steps indicated by blocks 108, 110, 112, 114, 118, 122, 124. If the extant conditioning mode is not an ordered conditioning mode, then method 100 continues via NO response line 130 and operation of the heat pump system is ceased, as indicated by a block 132. Method 100 terminates as indicated by an END block 134.

Heat pump system 10 (FIG. 1) is an illustration of the preferred embodiment of the present invention. It is important to note that the apparatus and method of the present invention are useful in other heat pump systems, such as systems embodied in what are known in the industry as package units. Package units are heat pump units that have both coils located within a single housing that is situated outside the conditioned space. The package unit is coupled with the conditioned space using air directing structures, such as air ducts.

It is to be understood that, while the detailed drawings and specific examples given describe preferred embodiments of the invention, they are for the purpose of illustration only, that the apparatus and method of the invention are not limited to the precise details and conditions disclosed and that various changes may be made therein without departing from the spirit of the invention which is defined by the following claims:

Claims

1. An apparatus for checking whether extant operation of a heat pump system is an ordered operation directed by a control device coupled with said heat pump system; said heat pump system including a compressor coupled with at least two fluid coils in fluid communication involving a direction-controlling valve; said ordered operation involving a characteristic systemic temperature range at a characteristic locus; the apparatus comprising:

(a) a temperature sensing device coupled with said heat pump system at said characteristic locus for determining a sensed systemic temperature; and

(b) a comparing device coupled with said temperature sensing device and with said heat pump system; said comparing device comparing said sensed systemic temperature with said characteristic systemic temperature range to effect said checking.

2. An apparatus for checking whether extant operation of a heat pump system is an ordered operation directed by a control device coupled with said heat pump system as recited in claim 1 wherein said at least two fluid coils includes an inside coil situated inside an enclosed space being conditioned by said heat pump system, and an outside coil situated outside said space; said characteristic locus being at said outside coil.

3. An apparatus for checking whether extant operation of a heat pump system is an ordered operation directed by a control device coupled with said heat pump system as recited in claim 1 wherein said direction-controlling valve exhausting refrigerant through a first fluid port to said inside coil during heating operations; said direction-controlling valve exhausting refrigerant through a second fluid port to said outside coil during cooling operations; said characteristic locus being at at least one of said first fluid port and said second fluid port.

4. An apparatus for checking whether extant operation of a heat pump system is an ordered operation directed by a control device coupled with said heat pump system as recited in claim 1 wherein said heat pump system responds to said checking by ceasing operation when said checking indicates said extant operation is not said ordered operation.

5. An apparatus for checking whether extant operation of a heat pump system is an ordered operation directed by a control device coupled with said heat pump system as recited in claim 2 wherein said heat pump system responds to said checking by ceasing operation when said checking indicates said extant operation is not said ordered operation.

6. An apparatus for checking whether extant operation of a heat pump system is an ordered operation directed by a control device coupled with said heat pump system as recited in claim 3 wherein said heat pump system responds to said checking by ceasing operation when said checking indicates said extant operation is not said ordered operation.

7. An apparatus for checking conditioning mode of a heat pump system; the apparatus comprising:

(a) a temperature sensing device coupled with said heat pump system at a sensing locus;

(b) a comparing device coupled with said temperature sensing device and configured for comparing a first temperature sensed by said temperature sensing device at a first time with a second temperature sensed by said temperature sensing device at a second time to determine an extant conditioning mode; said extant conditioning mode being a first said conditioning mode when said second temperature is greater than said first temperature; said extant conditioning mode being a second said conditioning mode when said second temperature is less than said first temperature.

8. An apparatus for checking conditioning mode of a heat pump system as recited in claim 7 wherein said heat pump system effects said conditioning in an inside space and wherein said heat pump system includes a compressor coupled with at least an inside coil inside said space and an outside coil outside said space; said inside coil and said outside coil being in fluid communication involving direction-controlling valve; said sensing locus being at said outside coil.

9. An apparatus for checking conditioning mode of a heat pump system as recited in claim 7 wherein said heat pump system effects said conditioning in an inside space and wherein said heat pump system includes a compressor coupled with at least an inside coil inside said space and an outside coil outside said space; said inside coil and said outside coil being in fluid communication involving direction-controlling valve; said direction-controlling valve exhausting refrigerant through a first fluid port to said inside coil during heating conditioning operations; said direction-controlling valve exhausting refrigerant through a second fluid port to said outside coil during cooling conditioning operations; said temperature sensing locus being at one of said first fluid port and said second fluid port.

10. An apparatus for checking conditioning mode of a heat pump system as recited in claim 7 wherein said heat pump system establishes an ordered conditioning mode in response to direction from a control device coupled with said heat pump system; said heat pump system ceasing operations when said comparing indicates that said extant conditioning mode is not said ordered conditioning mode.

11. An apparatus for checking conditioning mode of a heat pump system as recited in claim 8 wherein said heat pump system establishes an ordered conditioning mode in response to direction from a control device coupled with said heat pump system; said heat pump system ceasing operations when said comparing indicates that said extant conditioning mode is not said ordered conditioning mode.

12. An apparatus for checking conditioning mode of a heat pump system as recited in claim 9 wherein said heat pump system establishes an ordered conditioning mode in response to direction from a control device coupled with said heat pump system; said heat pump system ceasing operations when said comparing indicates that said extant conditioning mode is not said ordered conditioning mode.

13. A method for checking conditioning mode of a heat pump system; the method comprising the steps of:

(a) in no particular order: (1) providing a temperature sensing device coupled with said heat pump system at a sensing locus; and (2) providing a comparing device coupled with said temperature sensing device; and

(b) sensing a first temperature by said temperature sensing device at a first time;

(c) sensing a second temperature by said temperature sensing device at a second time;

(d) comparing said first temperature with said second temperature to determine an extant conditioning mode;

(e) if said second temperature is greater than said first temperature then said extant conditioning mode is a first said conditioning mode; and

(f) if said second temperature is less than said first temperature then said extant conditioning mode is a second said conditioning mode.

14. A method for checking conditioning mode of a heat pump system as recited in claim 13 wherein said heat pump system effects said conditioning in an inside space and wherein said heat pump system includes a compressor coupled with at least an inside coil inside said space and an outside coil outside said space; said inside coil and said outside coil being in fluid communication involving direction-controlling valve; said sensing locus being at said outside coil.

15. A method for checking conditioning mode of a heat pump system as recited in claim 13 wherein said heat pump system effects said conditioning in an inside space and wherein said heat pump system includes a compressor coupled with at least an inside coil inside said space and an outside coil outside said space; said inside coil and said outside coil being in fluid communication involving direction-controlling valve; said direction-controlling valve exhausting refrigerant through a first fluid port to said inside coil during heating conditioning operations; said direction-controlling valve exhausting refrigerant through a second fluid port to said outside coil during cooling conditioning operations; said temperature sensing locus being at one of said first fluid port and said second fluid port.

16. A method for checking conditioning mode of a heat pump system as recited in claim 13 wherein the method comprises the further step of:

(g) if said comparing indicates that said extant conditioning mode is not an ordered conditioning mode established by said heat pump system, ceasing operation of said heat pump system.

17. A method for checking conditioning mode of a heat pump system as recited in claim 14 wherein the method comprises the further step of:

(g) if said comparing indicates that said extant conditioning mode is not an ordered conditioning mode established by said heat pump system, ceasing operation of said heat pump system.

18. A method for checking conditioning mode of a heat pump system as recited in claim 15 wherein the method comprises the further step of:

(g) if said comparing indicates that said extant conditioning mode is not an ordered conditioning mode established by said heat pump system, ceasing operation of said heat pump system.