MX2007001457A

MX2007001457A - Heat pump system having auxiliary water heating and heat exchanger bypass

Info

Publication number: MX2007001457A
Application number: MX/A/2007/001457A
Authority: MX
Inventors: Murakami Toshio; Afonso Tesche Carlos; Gustavo Fernandez Roberto
Original assignee: Carrier Corporation; Gustavo Fernandez Roberto; Murakami Toshio; Springer Carrier Ltda; Afonso Tesche Carlos
Filing date: 2007-02-02
Publication date: 2008-10-03

Abstract

A heat pump system (10) includes a compressor (20), a reversing valve (30), an outdoor heat exchanger (40) and an indoor heat exchanger (50) coupled via refrigerant lines (35, 45, 55) in a conventional refrigeration circuit, a refrigerant to liquid heat exchanger (60), a refrigerant to liquid heat exchanger bypass valve (130), an outdoor heat exchanger bypass valve (230), and an indoor heat exchanger bypass valve (330). A controller (100) is provided to selectively control the respective positioning of the valves (30, 130, 230 and 330) between their respective open and closed positions so as to selectively configure the refrigerant circuit for operation in one of an air cooling only mode, an air cooling with liquid heating mode, an air heating only mode, an air heating with liquid heating mode, and a liquid heating only mode.

Description

HEAT PUMP SYSTEM THAT HAS AUXILIARY WATER HEATING AND TERMOINTER CHANGER DERIVATION DESCRIPTION OF THE INVENTION This invention relates generally to heat pump systems and, more particularly to heat pump systems that include auxiliary liquid heating, which include for example heating pool water, domestic water systems and the like. Reversible heat pumps are well known in the art and are commonly used to cool and heat a climate-controlled comfort zone with a residence or a building. A conventional heat pump includes a compressor, a suction accumulator, an inversion valve, an external heat exchanger with an associated fan, an internal heat exchanger with an associated fan, an expansion valve operatively associated with the external heat exchanger and a second temperature valve. expansion operatively associated with the internal heat exchanger. The aforementioned components are typically arranged in a closed coolant circuit pump system employing the well known refrigerant vapor compression cycle. When operating in the cooling mode, the excess heat absorbed by the refrigerant when passing through the internal heat exchanger is rejected to the environment as the refrigerant passes through the external heat exchanger. It is well known in the art that an additional water-to-water heat exchanger can be added to a heat pump system to absorb this excess heat for the purpose of heating water, rather than simply rejecting excess heat to the environment. In addition, heat pumps often have unused heating capacity when operating in the heating medium to heat the climate controlled zone. For example, each of U.S. Patent Nos. 3,188,829; 4,098,092, 4,492,092 and 5,184,472 discloses a heat pump system that includes an auxiliary hot water heat exchanger. However, these systems do not include any device to control the refrigerant charge within the refrigerant circuit. Therefore, while they are functional, these systems can not be optimally efficient in all modes of operation. In heat pump systems, the external heat exchanger and the internal heat exchanger each operate as an evaporator, condenser or subcooler, depending on the mode and point of operation. As such, condensation may occur in any of the heat exchangers, and the suction line may be filled with refrigerant in a gaseous or liquid state. As a consequence, the amount of system refrigerant charge required in each mode of operation to ensure an operation within an acceptable efficacy coverage will be different for each mode. US Patent 4,528,822 discloses a heat pump system that includes an additional liquid refrigerant heat exchanger to heat the liquid using heat that can otherwise be rejected into the environment. The system can be operated in four independent modes of operation: space heating, slow cooling, liquid heating and space cooling simultaneously with the heating of the liquid. In the liquid-only heating mode, the internal heat exchanger fan shuts off while in the space cooling and liquid heating mode, the external heat exchanger fan shuts off. A refrigerant charge tank is provided in which the liquid refrigerant is drained by gravity from the liquid refrigerant heat exchanger during the liquid heating only mode and the simultaneous slow cooling and liquid heating mode. However, with a control procedure they are described to effectively control the refrigerant charge in the refrigerant circuit in all modes of operation. In addition, no mode of space heating and simultaneous liquid heating is described.

Accordingly, it is desirable that the heat pump system with the liquid heating capacity effectively operate in an air-only cooling mode, an air-cooling and liquid-heating mode, an air-only-heating mode, a mode of heating of air and heating of liquid, and a mode of only heating of liquid. In one aspect, it is an object of the invention to provide a heat pump system having a capacity for air cooling, air heating and liquid heating. In one aspect it is an object of the invention to provide a heat pump system having a liquid refrigerant heat exchanger in addition to conventional external and internal heat exchangers, with the ability to selectively divert any of the aforementioned heat exchangers. In one embodiment of the invention, a heat pump system includes a refrigerant compressor, an internal heat exchanger and an external heat exchanger disposed in a refrigerant circuit; a selectively positioned four-port reversing valve having a first position for configuring the refrigerant circuit in an air-cooling mode and a second position for configuring the refrigerant circuit in an air-heating mode; a bypass valve of liquid coolant heat exchanger-a bypass valve of the external heat exchanger; and an internal heat exchanger bypass valve. The refrigerant circuit has a first refrigerant line that establishes a flow path between the discharge port of the compressor and the first port of the reversing valve, a second line of refrigerant that establishes a flow path between the second port of the refrigerant. reversing valve and the third port of the reversing valve, and a third refrigerant line that establishes a flow path between the fourth port of the reversing valve and the suction port of the compressor. The external heat exchanger is arranged in operative association with the second refrigerant line and is adapted to pass the refrigerant passing through the second refrigerant line in heat exchange relationship with the ambient air. The internal heat exchanger is arranged in operative association with the second refrigerant line and is adapted to pass the refrigerant which passes through the second refrigerant line in heat exchange relationship with the air from the comfort zone. The liquid refrigerant heat exchanger is arranged in operative association with the first refrigerant line and is adapted to pass the refrigerant which passes through the first refrigerant line in heat exchange relationship with a liquid. A bypass valve of the refrigerant to liquid heat exchanger that can be selectively disposed is provided in operative association with the first refrigerant line. The bypass valve of the refrigerant-to-liquid heat exchanger has a first position where the refrigerant that passes through the first refrigerant line from the compressor is directed to the first port of the reversing valve without passing through the liquid refrigerant heat exchanger and a second position where the refrigerant passing through the first refrigerant line from the compressor is directed through the refrigerant-to-liquid heat exchanger before passing to the first port of the reversing valve. A bypass valve of the external heat exchanger is provided in operative association with the second line of refrigerant at a location upstream of the external heat exchanger with respect to the flow of refrigerant when the heat pump system is operating in the air-only cooling mode. The valve The bypass of the external heat exchanger has a first position where the refrigerant passing through the second line of refrigerant from the second port of the reversing valve is directed to pass through the external heat exchanger and a second position where the refrigerant passing to the through the second refrigerant line from the second port of the reversing valve is directed to bypass the external heat exchanger. A bypass valve of the internal heat exchanger is provided in operative association with the second line of refrigerant in a location upstream of the internal heat exchanger with respect to the flow of refrigerant when the heat pump system is operating in air-only heating mode, the bypass valve of the internal heat exchanger has a first position where the refrigerant that passes through the second refrigerant line from the third port of the reversing valve is directed to pass through the internal heat exchanger and a second position where the refrigerant which passes through the second line of refrigerant from the third port of the reversing valve is directed to bypass the internal heat exchanger. In one embodiment, the refrigerant circuit may include a fourth refrigerant line connecting a port of the bypass valve of the external exchanger to the second refrigerant line at an intermediate location to the external heat exchanger and the internal heat exchanger and a fifth line of refrigerant which connects a port of the bypass valve of the internal heat exchanger with the second line of refrigerant in an intermediate location to the external heat exchanger and the internal heat exchanger. A controller is provided in operative association with the reversing valve, the bypass valve of the liquid refrigerant heat exchanger, the bypass valve of the external heat exchanger and the bypass valve of the internal heat exchanger, the operating controller to selectively control the respective placement of the aforementioned valves between their respective first and second positions for selectively configuring the refrigerant circuit for operation in one of a single air cooling mode, one air cooling mode with liquid heating, one air only heating mode, an air heating mode with liquid heating, and a liquid heating only mode. In one embodiment, a refrigerant reservoir having an inlet coupled to a fourth refrigerant line in fluid flow communication to the second refrigerant line at an intermediate location to the external heat exchanger and the internal heat exchanger and an output coupled through is provided. of a sixth line of refrigerant in fluid flow communication to the third line of refrigerant. A first flow control valve having an open position and a closed position can be provided to control the flow of refrigerants from the second refrigerant line to the inlet of the refrigerant tank and a second flow control valve having an open position and a closed position can be provided to control the flow refrigerant between the outlet of the refrigerant tank and the third refrigerant line. The controller may be operative to selectively control the respective positioning of the first and second flow control valves between their respective open and closed positions to selectively control the refrigerant charge within the refrigerant circuit. The first and second flow control valves may also have at least one partially open position and may comprise pulse-width modulated solenoid valves. The controller may further be operative to selectively modulate the respective placement of the flow control valves between their open, partially open and closed positions. In a further embodiment, a first expansion valve may be provided in the second refrigerant line in operative association with the internal heat exchanger and a second expansion valve may be provided in the second refrigerant line in operative association with the external heat exchanger. A first branch line of the expansion valve operatively associated with the second line of refrigerant provides the bypass of the refrigerant which passes through the second line of refrigerant in one direction from the external heat exchanger to the heat exchanger internally around the first expansion valve and through the second expansion valve. A second branch line of the second expansion valve operatively associated with the second line of refrigerant provides the bypass of the refrigerant passing through the second line of refrigerant in one direction from the internal heat exchanger to the external heat exchanger around the second. expansion valve and through the first expansion valve. BRIEF DESCRIPTION OF THE DRAWINGS For a further understanding of these and the objects of the invention, reference will now be made to the following detailed description of the invention which will be read in conjunction with the accompanying drawings, wherein: Figure 1 is a schematic diagram illustrating a first embodiment of the heat pump system of the invention illustrating the operation in an intimate air cooling only mode. Figure 2 is a schematic diagram illustrating a second embodiment of the heat pump system of the invention illustrating the operation in an internal air cooling only mode.; Figure 3 is a schematic diagram illustrating a first embodiment of the heat pump system of the invention illustrating operation in an indoor air cooling mode with water heating; Figure 4 is a schematic diagram illustrating a second embodiment of the heat pump system of the invention illustrating operation in an indoor air cooling mode with water heating Figure 5 is a schematic diagram illustrating a first embodiment of the system of heat pump of the invention illustrating the operation in a mode of internal air heating only; Figure 6 is a schematic diagram illustrating a second embodiment of a heat pump system of the invention illustrating operation in a single air heating mode; Figure 7 is a schematic diagram illustrating a first embodiment of the heat pump system of the invention illustrating operation in an internal air heating mode with water heating; Figure 8 is a schematic diagram illustrating a second embodiment of the heat pump system of the invention illustrating operation in an internal air heating mode with water heating; Figure 9 is a schematic diagram illustrating a first embodiment of the heat pump system of the invention illustrating the operation in a water-only heating mode; Figure 10A is a schematic drawing illustrating a second embodiment of the heat pump system of the invention illustrating the operation in a water-only heating mode; Figure 10B is a schematic drawing illustrating a third embodiment of the heat pump system of the invention illustrating the operation in a water-only heating mode; Figure 11 is a schematic diagram illustrating one embodiment of a control system arrangement for the heat pump system of the invention; Figure 12 is a block diagram illustrating a first embodiment of a refrigerant charge adjustment procedure at the start in a new mode of operation; Figure 13 is a block diagram illustrating a second embodiment of a refrigerant charge adjustment procedure at the start in a new mode of operation; Figure 14 is a block diagram illustrating a third embodiment of a refrigerant charge adjustment procedure at the start in a new mode of operation; Figure 15 is a block diagram illustrating a discharge temperature limit control method for adjusting the post-start of refrigerant charge; and Figure 16 is a block diagram illustrating a load control procedure for adjusting the postinicio of the refrigerant charge. The refrigerant heat pump system 10, represented in a first embodiment in Figures 1, 3, 5, 7 and 9 and a second embodiment in Figures 2, 4, 6, 8 and 10, not only provides heating or cooling of air in a comfort region, for example in an internal zone located inside a building (not shown), but also auxiliary water heating when desired. The system includes a compressor 20, a suction accumulator 22, a reversing valve 30 ·, an external heat exchanger 40 and associated fan 42 located on the outside of a building in heat transfer relationship with the surrounding environment, an internal heat exchanger 50 and associated fan 52 located in the comfort zone, a first expansion valve 44 operatively associated with the external heat exchanger 40 and a second expansion valve 54 operatively associated with the internal heat exchanger 50, a water-cooled heat exchanger 60, a valve 130. for bypass heat exchanger a first valve 230 bypass / purge and a second valve 330 bypass / purge. A refrigerant circuit including lines 35, 45 and 55 of refrigerant provides a closed-loop refrigerant flow path that couples these components in a conventional manner for a heat pump system employing a conventional refrigerant vapor compression cycle. The refrigerant can be directed through the refrigerant heat exchanger 60 to water where the refrigerant passes in heat exchange relationship with the water to be heated. The water to be heated is pumped by a circulation pump 62 via the line 65 of water circulation from a water tank 64, for example a hot water storage tank or a pool, through the heat exchanger 60 and back to the tank 64. The water-to-water heat exchanger 60 is operatively associated with the section 35B of the refrigerant line 35 whereby the refrigerant flowing through the refrigerant line 35 passes in heat exchange relationship with the water passing to it. through line 65 of water circulation.

The compressor 20, which may comprise a rotary compressor, a volute compressor, an oscillating compressor, a screw compressor or any other type of compressor, has a suction inlet for receiving the refrigerant from the suction accumulator 22 and an outlet to discharge the compressed refrigerant. The reversing valve 30 may comprise a selectively positionable two-position four-port valve having a first port 30-1, a second port 30-2, a third port 30-3 and a fourth port 30-4 . The reversing valve 30 may be placed in a first position for coupling the first port and the second port in fluid flow communication and for simultaneously coupling the third port and the fourth port in fluid flow communication. The reversing valve 30 may be placed in a second position for coupling the first port and the third port in fluid flow communication and for simultaneously coupling the second port and the fourth port in fluid flow communication. Advantageously, the respective port-to-port couplings established in the first and second positions are achieved internally within the valve 30. The outlet 28 of the compressor 20 is connected in fluid flow communication via the refrigerant line 35 to the first port 30. -1 of the reversing valve 30. The second port 30-2 of the reversing valve 30 is externally coupled by the valve in refrigerant flow communication to the third port 30-3 of the reversing valve 30 via the refrigerant line 45. The fourth port 30-4 of the reversing valve 30 is coupled in refrigerant flow communication to the suction inlet of the compressor 20 via the refrigerant line 55. When the heat pump system is operated in an air cooling mode, with or without water heating, the reversing valve 30 is placed in the first position as depicted in Figures 1, 2, 3 and 4. When The heat pump system is operated in an air heating mode, with or without water heating, the reversing valve 30 is placed in the second position as shown in Figures 5, 6, 7 and 8. When the The heat pump system is operated in a water-only heating mode, the reversing valve 30 is placed in the second position as shown in Figures 9 and 10. The external heat exchanger 40 and the internal heat exchanger 50 are operatively arranged in line 45 of refrigerant. The external heat exchanger 50 is connected in fluid flow communication via the section 45A of the refrigerant line 45 with the second port 30-2 of the reversing valve 30. The internal heat exchanger 50 is connected in fluid flow communication to the third port 30-3 of the reversing valve 30 via the section 45C of the refrigerant line 45. The section 45B of the refrigerant line 45 couples the external heat exchanger 40 and the internal heat exchanger 50 in refrigerant flow communication. A suction accumulator 22 can be arranged in the refrigerant line 55 on the suction side of the compressor 20, which has its inlet connected in refrigerant flow communication to the fourth port 30-4 of the reversing valve 30 through the section 55A of the refrigerant line 55 and having its outlet connected in refrigerant flow communication to the suction inlet of the compressor 20 through the section 55B of the refrigerant line 55. Therefore, the refrigerant lines 35, 45 and 55 together couple the compressor 20, the external heat exchanger 40 and the internal exchanger 50 in refrigerant flow communication, thereby creating a circuit for circulation of refrigerant flow through of the heat pump system 10. The first and second expansion valves 44 and 54 are disposed in the section 45B of the refrigerant line 45. In the embodiments shown in the drawings, the first expansion valve 44 is operatively associated with the external heat exchanger 40 and the second expansion valve 54 is operatively associated with the internal heat exchanger 50. Each of the expansion valves 44 and 54 is provided with a branch line equipped with a regulating valve that allows flow in a single direction. The regulating valve 46 and the bypass line 43 associated with the expansion valve 44 of the external heat exchanger passes the refrigerant flowing from the external heat exchanger 40 to the internal heat exchanger 50, thereby bypassing the expansion valve 44 of the external heat exchanger and passing refrigerant to the expansion valve 54 of the internal heat exchanger. Conversely, the regulating valve 56 in the bypass line 53 associated with the expansion valve 54 of the internal heat exchanger passes the refrigerant flowing from the internal heat exchanger 50 to the external heat exchanger 40, thereby bypassing the expansion valve 54 of the internal heat exchanger and passing the refrigerant to the expansion valve 44 of the external heat exchanger. The bypass valve 130 of the water-coolant heat exchanger comprises a four-port, two-position valve, which can be selectively positioned and has a first port 130-1, a second port 130-2, a third port 130-3, and a fourth port 130-4. The valve 130 can be placed in the first position to couple the first port 130-1 and the second port 130-2 in fluid flow communication and to simultaneously couple the third port 130-3 and the fourth port 130-4 in communication of fluid flow. The valve 130 can be placed in a second position to couple the first port 130-1 and the fourth port 130-4 in fluid flow communication and to simultaneously couple the second port 130-2 and the third port 130-3 in communication of fluid flow. Advantageously, the respective ports from port to port set in the first and second positions are achieved internally within the valve 130. The valve 130 is disposed in the refrigerant circuit within the first port 130-1 in fluid flow communication with the output of the compressor 20 through the section 35A upstream of the refrigerant line 35, with the second port 130-2 in fluid flow communication with the downstream section 35B of the refrigerant line 35 via the refrigerant line 35C , with the third port 130-3 in fluid flow communication with the refrigerant line 57, and with the fourth port 130-4 in fluid flow communication with the intermediate section 35B of the refrigerant line 35. A flow regulating valve 22 is arranged in the refrigerant line 35C and the flow regulating valve 24 is disposed in the intermediate section 35B of the refrigerant line 35. The regulating valve 22 allows the flow of refrigerant from the compressor 20 via the bypass valve 130 through the refrigerant line 35C to the section 35D downstream of the refrigerant line 35, but blocks the flow through the line 35C of the refrigerant in the reverse direction. Regulating valve 24 allows refrigerant flow from compressor 20 through port 130-4 of bypass valve 130 through section 35B of refrigerant line 35 to section 35D downstream of refrigerant line 35, but blocks the flow through section 35B of refrigerant line 35 in the reverse direction. The first bypass / purge valve 230 comprises a valve of four ports, of two positions, which are selectively positioned, having a first port 230-1, a second port 230-2, a third port 230-3 and a fourth port 230-4. The first valve 230 bypass / purge it can be placed in a first position for coupling the first port 230-1 and the second port 230-2 in fluid flow communication and for simultaneously coupling the third port 230-3 and the fourth port 230-4 in flow communication fluid.- The first bypass / purge valve 230 can be placed in a second position for coupling the first port 230-1 and the fourth port 230-4 in fluid flow communication and for simultaneously coupling the second port 130-2 and the third port 230-3 in fluid flow communication. Advantageously, the respective ports from port to port set in the first and second positions are achieved internally within valve 230. The first bypass / purge valve 230 is disposed in the refrigerant circuit in section 45A of line 45 of refrigerant with its first port 230-1 and in fluid flow communication via line 45A of refrigerant with the second port 30-2 of the reversing valve 30, and with its second port 230-2 in fluid flow communication with section 45B of line 45 of refrigerant. The second bypass / purge valve 330 comprises a selectively positionable, two position, lumen valve having a first port 330-1, a second port 330-2, a third port 330-3, and a fourth port 330 -4. The second bypass / purge valve 330 can be placed in a first position to couple the first port 330-1 and the second port 330-2 in fluid flow communication and to simultaneously couple the third port 330-3 and the fourth port 330-4 in fluid flow communication. The second bypass / purge valve 330 can be placed in a second position to couple the first port 330-1 and the fourth port 330-4 in fluid flow communication and to couple simultaneously the second port 330-2 and the third port 330-3 in fluid flow communication. Advantageously, the respective ports from port to port set in the first and second positions are internally achieved within the valve 330. The second bypass / purge valve 330 is arranged in the refrigerant circuit in the section 45C of line 45 of refrigerant with the first port 330-1 in fluid flow communication with line 45C of refrigerant, and with its second port 330-2 in fluid flow communication with third port 30-3 of reversing valve 30. The first bypass / purge valve 230 and second bypass valve 330 are connected in fluid flow communication through a bypass / purge circuit comprising refrigerant lines 25, 27 and 29. The third port 230-3 of the first bypass / purge valve 230 is connected in flow communication with the fourth port 330-4 of the second bypass / purge valve 330 by the section 25A of the refrigerant line 25. The fourth ignition 230-4 of the first bypass / purge valve 230 is connected in flow communication with the third port 330-3 of the second bypass / purge valve 330 via the refrigerant line 27. A flow regulating valve 26 and a flow regulating valve 28 are arranged in the refrigerant line 27. The refrigerant line 29 provides fluid flow communication between the refrigerant line 27 and the section 45B of the refrigerant line 45, intersects in fluid flow communication with the refrigerant line 27 at an intermediate location to the valves 26 and 28 flow regulators and crisscrossers in fluid flow communication through line 45 of refrigerant in an intermediate location flow control valves 48 and 58. The regulating valve 26 allows the flow of refrigerant through the section 27A of the refrigerant line 27 to the refrigerant line 29, but blocks the flow through the section 27A of the refrigerant line 27 in the reverse direction. Similarly, the regulating valve 28 allows the flow of refrigerant through the section 27B of the refrigerant line 27 to the refrigerant line 29, but blocks the flow through the section 27B of the refrigerant line 27 in the reverse direction . Additionally, a first flow control valve 48 is disposed in the section 45B of the refrigerant line 45 between the expansion valve 44 and the connection of the refrigerant line 29 in the line 45, and a second control valve 58 flow is arranged in section 45 is disposed in section 45B of refrigerant line 45 between expansion valve 54 and connection of refrigerant line 29 in line 45.

Advantageously, both flow control valves 48 and 58 can be solenoid valves which can be selectively positioned by a system controller (not shown) either the open position or the closed position. When the first bypass / purge valve 230 is placed in its first position, the flow of refrigerant passing through the refrigerant line 45 passes through the external heat exchanger 40. However, when the first bypass / purge valve 230 is placed in its second position, the purge control valve 48 is placed in its closed position, whereby the flow of refrigerant passes through a bypass circuit formed by the section 27A of the refrigerant line 27 and the refrigerant line 29 thus deriving the external heat exchanger 40. When the second bypass / purge valve 330 is placed in its first position, the flow of refrigerant passing through the refrigerant line 45 passes through the internal heat exchanger 50. However, when the second bypass / purge valve 330 is placed in its second position, the flow control valve 58 is placed in its closed position, whereby, the flow of refrigerant passes through a bypass circuit formed by the section 27B of the refrigerant line 27 and the refrigerant line 29 thus deriving the internal heat exchanger 50.

In the embodiment of the heat pump system 10 shown in Figures 2, 4, 6, 8 and 10, the system includes, in addition to the previously mentioned components, a suction line bypass valve 90 having a first position and a second position, a bypass flow control valve 92, such as for example a solenoid valve, having an open valve state and a closed valve state, a bypass line 93, a bypass line 95 and a valve 94 regulator. The suction line bypass valve 90, which may advantageously be a selectively positioned, two-position, four-port valve having a first port 90-1, a second port 90-2, a third port 90 -3 and a fourth port 90-4, the internal cooling circuit 50 and the reversing valve 30 are arranged on line 45C of the intermediate cooling circuit. The first port 90-1 of the suction line branch valve 90 is in flow communication with the refrigerant circuit line 45C. The second port 90-2 of the suction line bypass valve 90 is externally connected in refrigerant flow communication with the first port 330-1 of the second bypass valve 330, whereby the refrigerant line 45C will be in communication of refrigerant flow with the third port 30-3 of the reversing valve 30 provided that the bypass valve 90 of the suction line is in its first position, as illustrated in Figures 2, 4, 6, 10A and 10B. The refrigerant line 93 extends in flow communication between the refrigerant line 73 and the third port 90-3 of the suction line bypass valve 90. The refrigerant line 95 extends in flow communication between a fourth port 90-4 of the suction line bypass valve 90 and the refrigerant line 45C, which opens thereto at an intermediate location to the internal heat exchanger 50 and the bypass flow control valve 92, whereby lines 93 and 95 will also be connected in refrigerant flow communication provided that the discharge flow valve 90 of the suction line is in its first position. The bypass flow control valve 92 is arranged in the refrigerant line 45C and is operative to close the refrigerant line 45C to flow through it when in its closed valve state and to open the refrigerant line 45C to flow through it when it is in its open valve state. The regulating valve 94 is arranged in the refrigerant line 95 to allow the refrigerant to flow through the refrigerant line 95 from the suction line bypass valve 90 to the refrigerant line 45C, but to block the flow of refrigerant through the cooling line 95 from the cooling line 45C to the suction line bypass valve 90. As long as the suction line bypass valve 90 is in its second position, the refrigerant lines 45C and 93 are coupled in refrigerant flow communication, and the refrigerant line 95 will be coupled in refrigerant flow communication through the refrigerant. the first port 330-1 of the bypass valve 330, as illustrated in Figure 8. Because the bypass line 95 is used to convey hot liquid refrigerant to the internal heat exchanger the internal air heating mode with water heating , only the bypass line 95 is dimensioned with a diameter smaller than the section 45C of the refrigerant line 45, whereby the volume of the bypass line 95 will be substantially smaller than the volume of the section 45C of the line 45 of refrigerant, thereby reducing the refrigerant charge required to fill the refrigerant circuit in this mode. In the other modes of operation of the heat pump system, the bypass line regulator valve 92 closes and the refrigerant line 95 is connected only in refrigerant flow communication via the refrigerant lines 93 and 55A to the storage accumulator. suction whereby any refrigerant residing in line 95 is purged back to the suction accumulator 22 to return to the suction inlet of the compressor 20. In the system of the invention, the heat pump operates not only to heat or cool air in a comfort region, but also to heat water on request. Therefore, the system must operate effectively in an air-only cooling mode, an air-cooling and water-heating mode, an air-only mode, an air-heating mode and water heating, and a water heating mode only. Since the external heat exchanger 40 and the internal heat exchanger 50 operate as an evaporator, condenser or subcooler, depending on the mode and point of operation, the condensation can occur in one or two heat exchangers, and the suction line can be filled with the refrigerant in a gaseous or liquid state. As a consequence, the amount of refrigerant charge of the system required in each mode to ensure an operation within an envelope of acceptable efficiency will be different for each mode. When water heating is not required, the amount of refrigerant charge required will also be affected by the amount of heat exchange due to the occurrence of the thermal siphon movement in the water-to-water heat exchanger 60. Accordingly, the system 10 further includes a refrigerant storage tank 70, called a cargo tank, which has an inlet connected in fluid flow communication with the refrigerant line 45 via the refrigerant line 71 and an outlet connected in communication. of fluid flow through line 71 of refrigerant and an outlet connected in fluid flow communication with line 55 of refrigerant through the line 73 of coolant, a first flow control valve 72 disposed in the coolant line 71, and a second flow control valve 74 disposed in the coolant line 73. Each of the first and second valves 72 and 74 flow control has an open position and a closed position so that the flow through them can be controlled selectively so that the refrigerant charge within the refrigerant circuit can be actively controlled. Advantageously, each of the first and second flow control valves 72 and 74 may also have at least a partially open position and may be a pulse amplitude modulated solenoid valve. Additionally, a liquid level meter 80, such as for example a transducer, can be arranged in the cargo tank 70 to monitor the level of refrigerant inside the cargo tank. Referring now to Figure 11, a system controller 100, advantageously a microprocessor, controls the operation of the water pump 62, the compressor 20, the reversing valve 30, the bypass valve 130 of the heat exchanger, the first valve 230 bypass / purge, the second bypass / purge valve 330, and other components of the heat pump, such as the fan 42 of the external heat exchanger and fan 52 of the internal heat exchanger, in response to the cog or heating demand of the region of comfort in a conventional way and / or the demand for water heating. In the embodiment shown in Figures 6-10, the system controller also controls the operation of the suction line bypass valve 90 and the bypass flow control valve 92. In addition, the system controller 100 controls the opening and closing of the flow control valves 72 and 74 to adjust to the refrigerant charge to coordinate with the system requirements for the various modes of operation. The system controller 100 receives input signals indicative of various operational parameters of the system from a plurality of sensors, including without limitation, a suction temperature sensor 81, a suction pressure sensor 83, a discharge temperature sensor 85. , a discharge pressure sensor 87, a water temperature sensor 89, an external heat exchanger coolant temperature sensor 82, an internal heat exchanger coolant temperature sensor 84, and a coolant temperature sensor 86 arranged in association operative with section 45B of refrigerant line 45 at a location between expansion valves 44 and 54. The suction temperature sensor 81 and the suction pressure sensor 83 are arranged in operative association with the refrigerant lines 55 near the suction inlet to the compressor 20 as is the conventional practice for detecting the temperature and pressure of the refrigerant, respectively, the suction inlet of the compressor and to pass respective signals indicative thereof to the system controller 100. The discharge temperature sensor 85 and the discharge pressure sensor 87 are arranged in operative association with the refrigerant line 35 near the discharge outlet to the compressor 20 as in conventional practice to detect the temperature and pressure of the refrigerant, respectively at the compressor discharge outlet and for passing respective signals indicative thereof to the system controller 100. The water temperature sensor 89 is arranged in operative association with the water reservoir 64 to detect the temperature of the water therein and to pass a signal indicative of the detected water temperature to the system controller 100. The temperature sensor 82 is arranged in operative association with the external heat exchanger 40 at an appropriate location to measure the refueling phase change temperature of the refrigerant passing therethrough when the external heat exchanger is operating and to send an indicative signal of this detected temperature to the system controller 100. Similiarly, the temperature sensor 84 is arranged in operative association with the internal heat exchanger 50 at an appropriate location to measure the refrigerant phase change temperature of the refrigerant passing therethrough when the internal heat exchanger is operating and to send an indicative signal of that detected temperature to the system controller 100. The system controller 100 determines the degree of superheating of the refrigerant temperature detected by any of the sensors 82 and 84 that is associated with the heat exchanger that is acting as an evaporator in the current mode of operation. The coolant temperature sensor 86 operatively associated with the refrigerant line 45 detects the temperature of the refrigerant at a location between the expansion valves 44 and 54 and passes a signal indicative of the detected temperature to the system controller 100. The system controller determines the degree of sub-cooling present of the sensed temperature received from the temperature sensor 86. Referring now to Figures 1 and 2, in the indoor air cooling only mode, in response to a cooling demand, the system controller 100 places the reversing valve 30 in its first position, the bypass valve 130 heat exchanger in its first position, the first valve 230 bypass / purge in its first position, the second valve 330 bypass / purge in its first position, and activates the compressor 20-, the fan 42 of external heat exchanger and the fan 52 of internal heat exchanger. Additionally, both flow control valves 48 and 58 are set in their open position. The high-pressure superheated refrigerant of the compressor 20 passes through the refrigerant line 35A to the first port 130-1 of the bypass valve 130 of the heat exchanger where the refrigerant is directed via the second port to and through the lines 35C and 35D of refrigerant to the first port 30-1 of the reversing valve 30, thereby diverting the heat exchanger 60 from coolant to water. In the air cooling only mode, the water pump 62 is turned off so that the water is not flowing through the line 65. With the regulating valve 24 again blocking the flow to the line 35B of refrigerant, any refrigerant residing in the line 35B of refrigerant is again purged through the fourth port 130-4 of the bypass valve 130 to the third port 130-3 of the bypass valve 130 and therefore the refrigerant line 57 to the accumulator 22 to return to the suction inlet of the compressor 20. The refrigerant passing through the refrigerant line 35D to the reversing valve 30 is directed to and through the refrigerant line 45A to the external heat exchanger 40, which in the Air cooling mode works like a condenser. With the external heat exchanger fan 42 operating, the ambient air flows through the external heat exchanger 40 in heat exchange relationship with the refrigerant passing therethrough, whereby the high pressure refrigerant is condensed in a liquid and sub-cool. This high pressure liquid refrigerant passes from the external heat exchanger 40 through the section 45B of the refrigerant line 45 to the internal heat exchanger 50, which in the air cooling mode functions as an evaporator. Upon passing through the section 45B of the refrigerant line 45, the high pressure liquid refrigerant derives the expansion valve 44 through the bypass line 43 and the regulating valve 46 and therefore passes through the valve 54 of expansion where the high pressure liquid refrigerant is extended to a lower pressure, thereby further cooling the refrigerant before the refrigerant enters the internal heat exchanger 50. When the refrigerant crosses the internal heat exchanger 50, the refrigerant evaporates. With the fan 52 of the internal heat exchanger operating, the internal air passes through the internal heat exchanger 50 in heat exchange relationship with the refrigerant so that it evaporates the refrigerant and cools the internal air. In the embodiment of Figure 1 of system 10, the refrigerant vapor passes from the internal heat exchanger 50 through the section 45C of the refrigerant line 45 directly to and through the second bypass / purge valve 330 to the valve 30. of inversion where it is directed through section 55A of refrigerant line 55 to suction accumulator 22 before returning to compressor 20 through section 55B of refrigerant line 55 connecting suction inlet of compressor 20 In the embodiment of Figure 2 of the system 10, however, the purge valve 90 of the suction line is arranged in the refrigerant circuit between the internal heat exchanger 50 and the second bypass / purge valve 330. In this way, the refrigerant vapor passes from the internal heat exchanger 50 through the section 45C of the refrigerant line 45 directly to the first port 90-1, instead of directly to the first port 330-1 of the second valve. 330 bypass / purge. With the bypass / purge valve 90 of the suction line placed in its first position and the bypass flow control valve 92 placed in its first open position, as illustrated in Figure 2, the refrigerant vapor passes through of the suction line bypass / purge valve 90 through the ports 90-1 and 90-2 up and through the second bypass / purge valve 330 to the reversing valve 30 where it is directed through the section 55A of the refrigerant line 55 to the suction accumulator 22 before returning to the compressor 20 through the section 55B of the refrigerant line 55 connecting the suction inlet of the compressor 20. In addition, the lines 93 and 95 are also connected in flow communication by the suction line bypass valve 90 through the ports 90-3 and 90-4 and the flow to the line 95 of the refrigerant line 45C is blocked by the valve 94 regulatory Referring now to Figures 3 and 4, where there is a demand for water-heating together with internal air cooling, the system controller 100 returns the bypass valve 130 of the heat exchanger from its first position to its second position it also returns the first bypass / purge valve 230 from its first position to its second position, while allowing the reversing valve 30 in its first position and the second bypass / purge valve 330 in its first position. The controller also activates the water pump 62 in addition to the compressor 20 and the fan 52 of the internal heat exchanger, but turns off the fan 42 of the external heat exchanger and closes the flow control valve 48. With the bypass valve 130 of the heat exchanger in its second position, the superheated high pressure refrigerant from the compressor 20 passes through the refrigerant line 35A to the first port 130-1 of the bypass valve 130 of the heat exchanger where the refrigerant it is directed through the fourth port 130-4 up to and through the refrigerant lines 35B and 35D to the first port 30-1 of the reversing valve 30, whereby it passes through the refrigerant heat exchanger 60 to water. With the water pump 62 activated, water is pumped via the water line 65 from the storage tank 64 through the heat exchanger 60 in heat exchange relationship with the superheated high pressure refrigerant flowing through the line 35B of refrigerant. As the refrigerant passes through the heat exchanger 60, the refrigerant condenses and cools as it leaves the heat to heat the water flowing through the heat exchanger 60 in heat exchange relationship with the refrigerant. Since in this air cooling mode with water heating, the refrigerant passes into the section 45A of the refrigerant line 45 either condensed and subcooled as it passes through the heat exchanger 60 in heat exchange relationship with the water, there is no need for any significant additional cooling in the external heat exchanger . In addition, the additional subcooling can decrease the heating capacity of the water. When the first bypass / purge valve 230 is in its second position in this internal air cooling mode with water heating, the high pressure liquid refrigerant passing to the first bypass / purge valve 230 through its first port 230-1 is routed through its fourth port 230-4 in the refrigerant line 27A, thereby bypassing the external heat exchanger 40, and therefore through the refrigerant line 29 and the open flow control valve 58 to and through the internal heat exchanger 50 via line 45B of refrigerant. With the flow control valve 48 turned off and the first bypass / purge valve 230 in its second position, any refrigerant residing in the external heat exchanger is again purged through the first bypass / purge valve 230 via its second port 230- 2 and third port 230-3 up and through the lines 25A and 25B of refrigerant to the accumulator 22 to return to the suction inlet of the compressor 20. When passing through the line 45B of refrigerant, the high pressure liquid refrigerant it passes through the expansion valve 54 where the high pressure liquid refrigerant is extended to a lower pressure, thus further cooling the refrigerant before the refrigerant enters the internal heat exchanger 50. As the refrigerant crosses the internal heat exchanger, the refrigerant evaporates. With the fan 52 of the internal heat exchanger operating, the internal air passes through the internal heat exchanger 50 in heat exchange relationship with the refrigerant so that it evaporates the refrigerant and cools the internal air. In the embodiment of Figure 3 of system 10, the refrigerant vapor passes from the internal heat exchanger 50 through the section 45C of the refrigerant line 45 directly to and through the second bypass / purge valve 330 to the valve 30. of inversion where it is directed through section 55A of refrigerant line 55 to suction accumulator 22 before returning to compressor 20 through section 55B of refrigerant line 55 connecting suction inlet of compressor 20 In the embodiment of Figure 4 of the system 10, however, the purge valve 90 of the suction line is disposed in the refrigerant circuit between the internal heat exchanger 50 and the second bypass / purge valve 330. In this way, the refrigerant vapor passes from the internal heat exchanger 50 through the section 45C of the refrigerant line 45 directly to the first port 90-1, instead of directly to the first port 330-1 of the second valve. 330 bypass / purge. In the air-cooling mode with water heating, the suction line purge / bypass valve 90 and the flow control valve 92 are positioned as in the air-only cooling mode, with the bypass valve 90 suction line being placed in its first position and bypass flow control valve 92 being in its open position. Therefore, the refrigerant vapor passes through the suction line bypass / purge valve 90 via the ports 90-1 and 90-2 to and through the second bypass / purge valve 330 to the valve 30 of inversion where it is directed through section 55A of refrigerant line 55 to suction accumulator 22 before returning to compressor 20 through section 55B of refrigerant line 55 which is connected to the suction inlet of the compressor 20. Additionally, lines 93 and 95 are also connected in flow communication via suction line bypass valve 90 via ports 90-3 and 90-4 and flow to line 95 from line 45C of refrigerant is blocked by the regulating valve 94. Referring now to Figures 5 and 6, in the internal air heating only mode, in response to a heating demand, the system controller 100 places the reversing valve 30 in its second position, the bypass valve 130 heat exchanger in its first position, the first valve 230 bypass / purge in its first position, the valve 330 bypass / purge in its first position, and activates the compressor 20, the fan 42 of the external heat exchanger and the fan 52 of the internal heat exchanger . Additionally, both flow control valves 48 and 58 are set in their open position. The superheated high pressure refrigerant from the compressor 20 passes through the refrigerant line 35A to the first port 130-1 of the heat exchanger bypass valve 130 where the refrigerant is directed through the second port to and through the lines 35C and 35D of refrigerant to the first port 30-1 of the reversing valve 30, thereby diverting the heat exchanger 60 from coolant to water. With the reversing valve 30 in its second position, the refrigerant which passes through the refrigerant line 35D to the reversing valve 30 is directed by the first port 30-1 and the second port 30-2 thereof to the second port 330-2 of the second bypass / purge valve 330 where the refrigerant is directed by the second port 330-2 and the first port 330-1 thereof in the section 45C of the refrigerant line 45 and through the same up to the internal heat exchanger 50, which in the air heating mode functions as a condenser. In the air-only mode, the water pump 62 is turned off so that the water is not flowing through the line 65. With the regulating valve 24 again blocking the flow in the line 35B of refrigerant, any refrigerant residing in the refrigerant line 35B is again purged through the fourth port 130-4 of the bypass valve 130 to the third port 130-3 of the bypass valve 130 and therefore the refrigerant line 57 to the accumulator 22 for return to the suction inlet of the compressor 20. With the fan 52 of the internal heat exchanger operating, the internal air passes through the internal heat exchanger 50 in heat exchange relationship with the refrigerant passing therethrough, so the refrigerant High pressure is condensed in a liquid and subcooled, and the internal air is heated. The high pressure liquid refrigerant passes from the internal heat exchanger 50 through the section 45B of the refrigerant line 45 to the external heat exchanger 40, which in the air heating mode functions as an evaporator. Upon passing through the section 45B of the refrigerant line 45, the high pressure liquid derives the expansion valve 54 through the bypass line 53 and the regulating valve 56 and therefore passes through the valve 44 of expansion where the high pressure liquid refrigerant is extended to a lower pressure, thus further cooling the refrigerant before the refrigerant enters the external heat exchanger 40. With the external heat exchanger fan 42 operating, the ambient air passes through the external heat exchanger and as the refrigerant crosses the external heat exchanger, the refrigerant evaporates. The refrigerant passes from the external heat exchanger 40 through the section 45A of the refrigerant line 45 to and through the first bypass / purge valve 230 via the second port 230-2 and the first port 230-1 thereof until the reversing valve 30 where the refrigerant vapor is directed through the second port 30-2 and the fourth port 30-4 thereof up to and through the refrigerant line 55A to the suction accumulator 22 before returning to the compressor 20 through section 55B of the refrigerant line 55 which is connected to the suction inlet of the compressor 20.

In the embodiment of Figure 6 of the system 10, the purge valve 90 of the suction line is arranged in the refrigerant circuit between the internal heat exchanger 50 and the second bypass / purge valve 330. In this way, the refrigerant vapor passing through the second bypass / purge valve 330 through the ports 330-2 and 330-1 thereof passes to the second port 90-2 of the bypass valve 90 of the suction line. In the air-only mode, the suction line bypass / purge valve 90 and the flow control valve 92 are placed as in the air-only cooling mode, with the line 90 bypass valve suction being placed in its first position and bypass flow control valve 92 being in its open position. Therefore, the high pressure liquid refrigerant passes through the suction line bypass / purge valve 90 via the ports 90-2 and 90-1 and therefore through the refrigerant line 45C to the 50 internal heat exchanger. Additionally, lines 93 and 95 are also connected in flow communication by the suction line bypass valve 90 via ports 90-3 and 90-4, and flow to line 95 of line 45C of refrigerant is blocks through the regulator valve 94. Referring now to Figures 7 and 8, when there is a demand for water heating together with the internal air heating mode, the system controller 100 places the reversing valve 30 in its second position, the bypass valve 130 heat exchanger in its second position, the first valve 230 bypass / purge in its first position, and second valve 330 bypass / purge in its first position. The controller also activates the water pump 62 in addition to the compressor 20, the external heat exchanger fan 42 and the internal heat exchanger fan 52. Additionally, both flow control valves 48 and 58 are set in their open position. With the heat exchanger bypass valve 130 in its second position, the superheated high pressure refrigerant from the compressor 20 passes through line 35A of Coolant to the first port 130-1 of the heat exchanger bypass valve 130 where the refrigerant is directed via the fourth port 130-4 to and through the refrigerant lines 35B and 35D to the first port 30-1 of the valve 30 of investment, thus passing through the heat exchanger 60 from coolant to water. The controller 100 also activates the water pump 60 and the water is pumped via the water line 65 from the storage tank 64 through the heat exchanger 60 in heat exchange relationship with the high pressure superheated steam refrigerant flowing to the through line 35B of refrigerant. With the reversing valve 30 in its second position, the refrigerant which passes through the refrigerant line 35D to the reversing valve 30 is directed by the first port 30-1 and the second port 30-2 thereof to the second port 330-2 of the second bypass / purge valve 330 where the refrigerant is directed via the second port 330-2 and the first port 330-1 thereof up to and through the 45C section of the refrigerant line 45 to the internal heat exchanger 50, which in the air heating mode functions as a condenser. With the internal heat exchanger fan 52 operating, the internal air passes through the internal heat exchanger 50 in heat exchange relationship with the refrigerant passing through it, whereby the high pressure refrigerant is condensed in a liquid and sub-cooling and the internal air is heated. The high pressure liquid refrigerant passes from the internal heat exchanger 50 through the section 45B of the refrigerant line 45 to the external heat exchanger 40, which in the air heating mode works as an evaporator. Upon passing through the section 45B of the refrigerant line 45, the high pressure liquid refrigerant derives the expansion valve 54 through the bypass line 53 and the regulating valve 56 and therefore passes through the expansion valve 44 where the high pressure liquid refrigerant is extended to a lower pressure, thus further cooling the refrigerant before the refrigerant enters the external heat exchanger 40. With the external heat exchanger fan 42 operating, the ambient air passes through the external heat exchanger and as the refrigerant crosses the external heat exchanger, the refrigerant evaporates. The refrigerant passes from the external heat exchanger 40 through the section 45A of the refrigerant line 45 to and through the first bypass / purge valve 230 via the second port 230-2 and the first port 230-1 thereof to the reversing valve 30 wherein the refrigerant vapor is directed through the second port 30-2 and the fourth port 30-4 thereof to and through the refrigerant line 55A to the suction accumulator 22 before returning to the compressor 20 through the section 55B of the refrigerant line 55 which is connected to the suction inlet of the compressor 20. In the embodiment of Figure 8 of the system 10, the purge valve 90 of the suction line is disposed in the refrigerant circuit between the internal heat exchanger 50 and the second bypass / purge valve 330. In this way, the refrigerant vapor passing through the second bypass / purge valve 330 through the ports 330-2 and 330-1 thereof passes to the second port 90-2 of the bypass valve 90 of the suction line. In the air heating mode with water heating, the bypass valve 90 of the suction line is placed in its second position and the flow control valve 92 is placed in its closed position. With the suction line bypass valve 90 being placed in its second position, the high pressure liquid refrigerant passes through the bypass / purge valve 90 of the suction line through ports 90-2 and 90- 4 and therefore through line 95 of refrigerant and regulating valve 94 to internal heat exchanger 50. Additionally, line 93 and section 45C of coolant port 45 are connected in flow communication by suction line bypass valve 90 via ports 90-1 and 90-3, and flow to line 45C of the refrigerant line 95 is blocked by the second flow control valve 92. Any refrigerant resident in the 45C section of the refrigerant line 45 is purged to the suction accumulator through the refrigerant lines 93 and 73. Referring now to Figures 9 and 10, when there is a demand for water heating while the heat pump is also not in the internal air cooling or air heating mode, the system controller 10 places the reversing valve 30 in its second position, the heat exchanger bypass valve 130 in its second position, the first bypass / purge valve 230 in its first position, and the second bypass / purge valve 330 in its second position. The controller 100 also activates the water pump 62 in addition to the compressor 20 and the external heat exchanger fan 52, but turns off the internal heat exchanger fan 52 and closes the flow control valve 58. With the heat exchanger bypass valve 130 in its second position, the high-pressure superheated refrigerant of the compressor 20 passes through the refrigerant line 35A to the first port 130-1 of the heat exchanger bypass valve 130 where the refrigerant is directed by the fourth port 130-4 to and through the refrigerant lines 35B and 35D to the first port 30-1 of the reversing valve 30, thus passing through the heat exchanger 60 from coolant to water. With the water pump 62 activated, water is pumped via the water line 65 from the storage tank 64 through the heat exchanger 60 in heat exchange relationship with the superheated high pressure refrigerant flowing through the line 35B of refrigerant. When the refrigerant passes through the heat exchanger 60, the refrigerant is condensed and subcooled as it leaves the heat to heat the water flowing through the heat exchanger 60 in relation to heat exchange with the refrigerant. With the reversing valve 30 in its second position, the refrigerant passing through the refrigerant line 35D to the reversing valve 30 is directed by the first port 30-1 and the third port 30-3 thereof until the second port 330-2 of the second bypass / purge valve 330. When the second bypass / purge valve 330 is in its second position in this water-only mode, the high-pressure liquid refrigerant passing to the second bypass / purge valve 330 through its second port 330-2 it is directed through its third port 330-3 to the refrigerant line 27B, thereby bypassing the internal heat exchanger 50, and therefore through the refrigerant line 29 and the open flow control valve 48 to and through the external heat exchanger 40 via line 45B of refrigerant. Upon passing through the refrigerant line 45B, the high pressure liquid refrigerant passes through the expansion valve 44 where the high pressure liquid refrigerant is extended to a lower pressure, thus further cooling the refrigerant before that the refrigerant enters the external heat exchanger 40. When the refrigerant crosses the external heat exchanger, the refrigerant evaporates. With the fan 42 of the external heat exchanger operating, the ambient air passes through the external heat exchanger 40 in heat exchange relationship with the refrigerant thereby evaporating the refrigerant. The refrigerant vapor passes from the external heat exchanger 40 through the section 45A of the refrigerant line 45 through the first bypass / purge valve 230 through its second port 230-2 and the first port 230-1 to the valve 30 which is directed through its second port 30-2 and the fourth port 30-4 through the refrigerant line 55A to the suction accumulator 22 before returning to the compressor 20 through line 55B of refrigerant which is connects to the suction inlet of the compressor 20. With the flow control valve 58 turned off and the second bypass / purge valve 330 in its second position, any refrigerant residing in the internal heat exchanger 50 is purged again through the second valve 330 bypass / purge through its first port 330-1 and its fourth port 330-4 up and through the line 25B of refrigerant to the accumulator 22 to return to the input suction stroke of the compressor 20. In the embodiments shown in Figures 10A and 10B, where the suction line bleed valve 90 is disposed in the refrigerant circuit between the second bypass / purge valve 330 and the internal heat exchanger 50, any refrigerant residing in the internal heat exchanger 50 is purged again through the line 45C of refrigerant from the open flow control valve 92 to and through the suction line bypass valve 90 through its second port 90-2 which it is externally connected in fluid flow communication with the first port 330-1 of the second bypass / purge valve 330. The suction line bypass valve may be positioned in its first position, as shown in Figure 10A, or in its second position, as shown in Figure 10B. With reference now to Figure 10A, with the suction line bypass valve in its first position, with the flow control valve 58 closed, any refrigerant resident in the internal heat exchanger 50 is again purged through the suction line bypass valve 90 through the ports 90-1 and 90-2 thereof and through the bypass / purge valve 330 through its first port 330-1 and fourth port 330-4 up and through line 25B of refrigerant and line 55A of refrigerant to the accumulator 22 to return to the suction inlet of the compressor 20. Referring now to Figure 10B, with the suction line bypass valve in its second position, with the closed flow control valve 58, any refrigerant residing in the internal heat exchanger 50 is again purged through the suction line bypass valve 90 via ports 90-1 and 90-3 thereof through lines 93 and 55A of Coolant to the suction accumulator 22 to return to the suction inlet of the compressor 20. As noted above, the heat pump system of the invention must operate effectively in an air-only cooling mode, a cooling mode of air and water heating, a mode of air-only heating, a mode of air heating and water heating, and a water-only heating mode. As the external heat exchanger 40 and the internal heat exchanger 50 operate as an evaporator, condenser or subcooler, or are derived depending on the mode and point of operation, the condensation can occur in one or two heat exchangers, and the suction line can be filled with refrigerant in a gaseous or liquid state. As a consequence, the amount of refrigerant charge of the system required in each mode to ensure an operation within an envelope of acceptable efficiency will be different for each mode. When water heating is not required, the amount of refrigerant charge required will also be affected by the amount of heat exchange due to the occurrence of thermal siphon movement in the water-to-water heat exchanger 60. Accordingly, the system controller system 100 controls the amount of refrigerant flowing through the refrigerant circuit at any time, i.e. the refrigerant charge, by monitoring and adjusting the level of refrigerant in the cargo tank 70 to the selectively opening and closing the first flow control valve 72 disposed in the refrigerant line 71 and a second flow control valve 74 arranged in the refrigerant line 73. The controller 100 uses the input of the various sensors, which include the coolant temperature sensors 82 and 84 to calculate the degree of superheating and the degree of sub-cooling present in the system, which is used by the controller 100 to place the flow control valves 72 and 74 associated with the loading tank 70 as discussed in the foregoing. In a more advantageous embodiment, the charging tank 70 is provided with a liquid level meter 80 which generates and transmits a signal indicative of refrigerant level within the charging tank 70 to the system controller 100. The liquid level meter 80 can be configured to transmit a liquid level signal to the system controller 100 continuously, on a periodic basis at specific intervals, or only when required by the controller. Referring now to Figure 10, in operation, when the controller changes from one mode of operation to a new mode of operation, the controller 100 turns on the compressor 20 in the block 101, and then, in the block 102, the controller 100 compares the current liquid level then in the loading tank 70 with the last liquid level experienced the last time the system was operated in a mode equivalent to the new mode of operation, the last liquid level experienced when the controller memory was stored. If the current level is the same as the last level experienced for this particular mode of operation, the controller in block 105 activates the discharge temperature control procedure and / or in block 106 the normal load control procedure. However, if the current liquid level is not the same as the last level experienced for this particular mode of operation, the controller 100 will selectively modulate the solenoid valves 72 and 74 to open and close when necessary to adjust the liquid level current to equal the last level experienced for this particular mode of operation. If the current level is below the last experienced level, in block 103 the controller 100 will close the solenoid valve 74 and modulate the open solenoid valve 72 to drain the refrigerant from the refrigerant circuit to the loading tank 70 until the current reach the last level of experience. Conversely, if the current level is below the last experienced level, the controller 100 in block 104 will close the solenoid valve 72 and modulate the open solenoid valve 74 to drain the refrigerant from the charge tank 70 to the refrigerant circuit. until the current liquid level reaches the last experienced level. For example, the controller will open the appropriate valve for a short period of time, for example 2 seconds, close the valve, check the level again and repeat this sequence until the current liquid level is equal to the last level experienced. Once the current level has been matched to the last experienced level, the controller activates the normal load control procedure and / or the discharge temperature control procedure. The system controller 100 may also employ the control procedure discussed herein in embodiments of the heat pump system of the invention that do not include a liquid level sensor in association with the charge tank 70. However, when the heat pump system changes to a new mode of operation, the system controller 100 first fills the cargo tank with refrigerant in the liquid state or with the refrigerant in the gaseous state depending on the particular mode of operation that is applied. enter * If the new mode of operation does not involve water heating, the system controller will proceed according to the procedure illustrated by the block diagram in Figure 11 to fill the tank 70 with refrigerant liquid refrigerant. After turning on the compressor 20 in block 201, the system controller in block 202 closes solenoid valve 74 and opens solenoid valve 72 to allow liquid refrigerant to pass from line 71 to charging tank 70. After a programmed time delay in block 203 sufficient to allow the charging tank 70 to be filled with liquid refrigerant, for example, about 3 minutes, the system controller proceeds to adjust the charge of the refrigerant circuit when needed by the discharge temperature control procedure and / or the load control procedure in block 205 when desired. The solenoid valve 72 can be placed either open or closed at this point. However, if the new mode of operation involves water heating, the system controller will proceed according to the procedure illustrated by the block diagram in Figure 12 to fill the refrigerant tank 70 with gaseous refrigerant. After turning on the compressor 20 in the block 211, the system controller in the block 212 closes the solenoid valve 72 and modulates the on or off of the solenoid valve 74 for a period of time, for example, opened for 3 seconds, closed during 17 seconds repeatedly for two minutes to allow the refrigerant in the gaseous state to pass from line 73 to the loading tank 70. After a programmed time delay in block 213 sufficient to allow filling tank 70 to be filled with liquid refrigerant, for example, about 3 minutes, the system controller proceeds to adjust the charge of the refrigerant circuit when needed by the discharge temperature control method in block 214 and the load control procedure in block 215 when want. Solenoid valve 74 can be placed either open or closed at this point. In any water heating mode, the controller 100 will turn off the pump 62 when the temperature sensor 89 detects that the water temperature in the water tank 64 has reached a value of the desired limit, for example 60 ° C. According to the discharge temperature limit control procedure, illustrated by the block diagram of Figure 13, with the input of a fixed expansion mode, after turning on the compressor 20 in block 301 and a short delay of time, for example, approximately 30 seconds, the system controller in block 302 compares the current discharge temperature, TDC, that is, the temperature of the refrigerant being discharged from the compressor 20, received from the temperature sensor 85 within a limit of discharge temperature, TDL, preprogrammed in the controller 100. A typical compressor discharge limit may be a desired number of degrees, for example about 7 degrees C, conforming to the manufacturer's application guide specification. A typical compressor discharge temperature limit may be approximately 128 degrees C. If the current discharge temperature, TDC, exceeds the discharge temperature limit, the system controller 100 in block 303 disables the load control procedure if it is currently active, and then in block 304 closes the solenoid valve 72 and modulates the open solenoid valve 74 to drain the refrigerant from the charge tank 70 into the refrigerant circuit through the refrigerant line 73. If the current discharge temperature received from the temperature sensor 85 is equal to or less than the discharge temperature limit, the system controller 100 in block 305 activates the load control procedure if it is not currently active and proceeds to follow the load control procedure to adjust the refrigerant charge in the refrigerant circuit when necessary. In the charge control procedure, illustrated in Figure 14, with the refrigerant charge initially established, after ensuring that the compressor 20 is active in the block 400, the system controller 100 in the block 401 closes both valves 72 and 74 solenoids. After a brief time delay, for example about one minute, depending on the particular mode of current operation, the system controller in block 403 will compare either or both of the degree of superheat or the degree of sub-cooling presently present in the system with a pre-programmed allowable superheat allowance in controller 100. For example, in the air-only cooling and air-cooling modes with water heating, the allowable superheat allowance may be 0.5 to 20 degrees C and the allowable allowable Sub-cooling can be from 2 to 15 degrees C. In the modes of only air heating, air heating with water heating and only water heating, the allowable superheat allowance can be 0.5 to 11 degrees C and the margin Allowable sub-cooling can be 0.5 to 10 degrees C, for example. After determining in block 402 that the system is operating in a fixed expansion mode, the system controller, in block 403, compares the current degree of superheating against the allowable pre-programmed superheat in controller 100. If the degree If the current superheat is below the allowable range, in block 404, the system controller 100 will modulate the open solenoid valve 72 to drain the refrigerant from the refrigerant circuit in the charge tank 70. If the current degree of superheating is above the allowable range, in block 405, the system controller 100 will modulate the open solenoid valve 74 to drain the refrigerant from the charge tank 70 into the refrigerant circuit. If the degree of superheating falls within the permissible superheat range, the system controller proceeds to block 406. If operating in a mode without fixed expansion, the system controller, in block 407, compares the current degree of sub-cooling against a permissible sub-cooling allowance programmed into the controller. If the current degree of subcooling is above the allowable range, in block 404, the system controller 100 will modulate the open solenoid valve 72 to drain the refrigerant from the refrigerant circuit in the charge tank 70. If the current degree of sub-cooling is below the allowable range, in block 405, the system controller 100 will modulate the open solenoid to drain the refrigerant from the charge tank 70 into the refrigerant circuit. If the degree of subcooling falls within the allowable under-cooling range, the system controller proceeds to control the refrigerant charge through the charge control procedure and the discharge temperature limit control procedure as described. . The various control parameters presented as examples in the foregoing, such as the compressor discharge temperature limit, the various time delays, the desired superheating margins, the desired sub-cooling ranges, are for a capacity of 5 tons. typical, the divided system heat pump system having a bronze plate water coolant heat exchanger 60, a coolant tank 70 (cargo tank) having a storage capacity of liquid refrigerant of 4 kilograms, a charge of refrigerant system of 8 kilograms, and lines of general refrigerants of 7 meters. These parameters are presented for purposes of illustration and those skilled in the art will understand that these parameters may vary from the examples presented for different configurations and heat pump capacities. Those of ordinary skill in the art will select precise parameters to be used to implement the invention to better suit the operation of any particular heat pump system. While the present invention has been shown and described particularly with reference to the preferred mode as illustrated in the drawings, it will be understood by one skilled in the art that various changes in detail may be made therein without departing from the spirit and scope of the invention. as defined by the claims.

Claims

CLAIMS 1. A refrigerant circuit heat pump system that can operate in at least one air cooling mode and one air heating mode and has liquid heating capacity characterized in that it comprises: a refrigerant compressor which has a suction port and a discharge port; a selectively disposable reversing valve having a first port, a second port, a third port and a fourth port, the reversing valve can be placed in a first position for coupling to the first port and the second port in communication of fluid flow and the third port and the fourth port in fluid flow communication, the reversing valve can be placed in a second position to couple the first port and the third port in fluid flow communication and the second port and the fourth port in fluid flow communication; a refrigerant circuit that provides a closed-loop refrigerant circulation flow path, the refrigerant circuit has a first refrigerant line that establishes a flow path between the compressor discharge port and the first port of the reversing valve , a second line of refrigerant that establishes a flow path between the second port of the reversing valve and the third port of the reversing valve, and a third line of refrigerant that establishes a flow path between the fourth port of the valve of investment and the suction port of the compressor; an external heat exchanger operatively associated with the second refrigerant line and adapted to pass the refrigerant passing through the second refrigerant line in heat exchange relationship with the ambient air; an internal heat exchanger operatively associated with the second refrigerant line and adapted to pass the refrigerant passes through the second refrigerant line in heat exchange relationship with the air from the comfort zone, the internal heat exchanger arranged downstream of the external heat exchanger with respect to the flow of refrigerant in the air cooling mode and upstream of the external heat exchanger with respect to the flow of refrigerant through the second line of refrigerant in the air heating mode; a liquid refrigerant heat exchanger operatively associated with the first refrigerant line and adapted to pass the refrigerant passing through the first refrigerant line in heat exchange relationship with a liquid; a liquid refrigerant heat exchanger bypass valve can be selectively placed operatively associated with the first refrigerant line, between the bypass valve of refrigerant to liquid heat exchanger has a first position, where the refrigerant passing through the first line of refrigerant from the compressor is directed to the first port of the reversing valve without passing through the refrigerant heat exchanger to liquid and a second position where the refrigerant passing through the first refrigerant line from the compressor is directed through from the coolant to liquid heat exchanger before passing to the first port of the reversing valve; an external heat exchanger bypass valve operatively associated with the second refrigerant line at a location upstream of the external heat exchanger with respect to the flow of refrigerant when the heat pump system is operating in the air-only cooling mode, the Bypass of external heat exchanger has a first position where the refrigerant that passes through the second line of refrigerant from the second port of the reversing valve is directed to pass through the external heat exchanger and a second position where the refrigerant passing through of the second line of refrigerant from the second port of the reversing valve is directed to bypass the external heat exchanger; and a bypass valve of the internal heat exchanger operatively associated with the second line of refrigerant in a location upstream of the internal heat exchanger with respect to the flow of refrigerant when the heat pump system is operating in the heating only mode, the bypass valve of the internal heat exchanger has a first position where the refrigerant passing through the second refrigerant line from the third port of the reversing valve is directed to pass through the internal heat exchanger and a second position where the refrigerant passing through The second line of refrigerant from the third port of the reversing valve is directed to bypass the internal heat exchanger.
2. The heat pump system according to claim 1, characterized in that the refrigerant circuit further comprises: a fourth line of refrigerant connecting a port of the bypass valve of the external heat exchanger with the second line of refrigerant in a location intermediate to the external heat exchanger and the internal heat exchanger; and a fifth line of refrigerant connecting a port of the bypass valve of the internal heat exchanger with the second line of refrigerant in an intermediate location to the external heat exchanger and the internal heat exchanger.
3. The heat pump system according to claim 2, further characterized in that it comprises: a controller operatively associated with the reversing valve, the bypass valve of the refrigerant to liquid heat exchanger, the bypass valve of the external heat exchanger and the bypass valve of the internal heat exchanger, the operating controller to selectively control the respective positioning of the valves between their respective first and second positions to selectively configure the refrigerant circuit for operation in one of a single air cooling mode, one mode air cooling with liquid heating, a single air heating mode, an air heating mode with liquid heating, and a liquid heating only mode.
4. The heat pump system according to claim 3, further characterized in that it comprises: a first expansion valve arranged in the second line of intermediate coolant to the external heat exchanger and the internal heat exchanger; and a second expansion valve disposed in the second line of intermediate coolant to the internal heat exchanger and the first expansion valve; the first expansion valve is operatively associated with the internal heat exchanger and the second expansion valve is operatively associated with the external heat exchanger.
The heat pump system according to claim 4, further characterized by comprising: a first branch line of the expansion valve operatively associated with the second line of refrigerant to bypass the refrigerant passing through the second line of refrigerant in one direction from the external heat exchanger to the internal heat exchanger around the first expansion valve and through the second expansion valve.
The heat pump system according to claim 4, further characterized by comprising: a second expansion valve bypass line operatively associated with the second refrigerant line to bypass the refrigerant passing through the second line of coolant in one direction from the internal heat exchanger to the external heat exchanger around the second expansion valve and through the first expansion valve.
The heat pump system according to claim 3, further characterized by comprising: a coolant reservoir having an inlet coupled in fluid flow communication in the second refrigerant line at an intermediate location to the external heat exchanger and the internal heat exchanger and having an output coupled in fluid flow communication with the third line of the refrigerant.
8. The heat pump system according to claim 7, further characterized by comprising: a first flow control valve operatively associated with the coolant reservoir for controlling the flow of refrigerant from the second refrigerant line to the inlet of the refrigerant reservoir, the first control valve having an open position and a closed position; and a second flow control valve operatively associated with the coolant reservoir for controlling the flow of refrigerant between the outlet of the refrigerant reservoir and the third refrigerant line, the second control valve having an open position and a closed position; the first and second flow control valves operatively associated with the controller, the controller is operative to selectively control the respective positioning of the first and second flow control valves between their respective open and closed positions to selectively control the refrigerant charge within of the refrigerant circuit.
9. A refrigerant circuit heat pump system that can selectively operate in each of a single air-cooling mode, an air-only mode, a liquid-only-only mode, an air-cooling mode combined and liquid heating, and a mode of air heating and combined liquid heating, characterized in that it comprises: a refrigerant compressor having a suction port and a discharge port; a selectively positioned reversing valve having a first port, a second port, a third port, and a fourth port, the reversing valve can be placed in a first position to couple the first port and the second port in communication of fluid flow and the third port and the fourth port in fluid flow communication, the reversing valve can be placed in a second position to couple the first port and the third port in fluid flow communication and the second port and the fourth port in fluid flow communication; a refrigerant circuit that provides a closed-loop refrigerant circulation flow path, the refrigerant circuit has a first refrigerant line that establishes a flow path between the discharge ports of the compressor and the first port of the reversing valve , a second line of refrigerant that establishes a flow path between the second port of the reversing valve and the third port of the reversing valve, and a third line of refrigerant that establishes the flow path between the fourth port of the valve of investment and the suction port of the compressor; an external heat exchanger operatively associated with the second refrigerant line and adapted to pass the refrigerant passing through the second refrigerant line in heat exchange relationship with the ambient air; an internal heat exchanger operatively associated with the second refrigerant line and adapted to pass the refrigerant passing through the second refrigerant line in heat exchange relationship with the air from a comfort zone, the internal heat exchanger disposed downstream of the heat exchanger external with respect to the refrigerant flow in the air-only cooling mode and upstream of the external heat exchanger with respect to the refrigerant flow through the second refrigerant line in the air-only mode; a liquid refrigerant heat exchanger operatively associated with the first refrigerant line and adapted to pass the refrigerant passing through the first refrigerant line in heat exchange relationship with a liquid-a bypass valve of the refrigerant to liquid heat exchanger which can be selectively associated operatively with the first refrigerant line, the bypass valve of refrigerant to liquid heat exchanger has a first position where the refrigerant passing through the first refrigerant line from the compressor is directed to the first port of the reversing valve without passing through the refrigerant-to-liquid heat exchanger and a second position where the refrigerant passing through the first refrigerant line from the compressor is directed through the refrigerant-to-liquid heat exchanger before passing to the first luminary of the vá investment valve; an external heat exchanger bypass valve operatively associated with the second refrigerant line at a location upstream of the external heat exchanger with respect to the flow of refrigerant when the heat pump system is operating in the air-only cooling mode, the Bypass of the external heat exchanger has a first position where the refrigerant passing through the second refrigerant line from the second port of the reversing valve is directed to pass through the external heat exchanger and a second position where the refrigerant passing through of the second refrigerant line from the second port of the reversing valve is directed to bypass the external heat exchanger; a bypass valve of the internal heat exchanger operatively associated with the second line of refrigerant in a location upstream of the internal heat exchanger with respect to the flow of refrigerant when the heat pump system is operating in the air-only mode of heating, the valve of Bypass of the internal heat exchanger has a first position where the refrigerant that passes through the second refrigerant line from the third port of the reversing valve is directed to pass through the internal heat exchanger and a second position where the refrigerant passing through of the second refrigerant line from the third port of the reversing valve is directed to bypass the internal heat exchanger; and a suction line bypass circuit to direct the flow of refrigerant from the bypass valve of the internal heat exchanger to the internal heat exchanger when the heat pump system is operating in the combined air heating and liquid heating mode. A heat pump system according to claim 9, characterized in that the suction line bypass circuit comprises: a suction bypass valve operatively associated with the third line of refrigerant at an intermediate location to the bypass valve of the internal heat exchanger and the internal heat exchanger and has a first port, a second port, a third port and a fourth port, the bypass valve of the suction line can be selectively placed in a first position for coupling to the first port and the second port in refrigerant flow communication and the third port and fourth port in refrigerant flow communication, the suction bypass valve can be selectively placed in a second position to couple to the first port and the third port in communication of flow of fluid, and the second port and the fourth lumbr was in fluid flow communication, the first port is connected in refrigerant flow communication with the internal heat exchanger by the second refrigerant line, and the second port is connected in refrigerant flow communication with the bypass valve of the internal heat exchanger; a suction line bypass line connecting the fourth port of the suction line bypass valve in refrigerant flow communication, with the internal heat exchanger, the suction line bypass line that is in parallel in flow relation of refrigerant with at least a portion of the second refrigerant line connecting the first port of the bypass valve of the suction line in refrigerant flow communication with the internal heat exchanger.