A supplemental heat-providing system is provided for heating a refrigerant. The system includes an outdoor unit that can act as a heat pump located outside a building and configured to use the refrigerant to condition an indoor space inside the building; a hot water heater located in the building and connected to one or more points of use in the building, the hot water heater being configured to heat water and provide the water to the one or more points of use; a water-refrigerant heat exchanger containing a refrigerant pathway and a water pathway, configured to pass the refrigerant from the outdoor unit through the refrigerant pathway, to pass the water from the hot water heater through the water pathway, and to exchange heat from the water to the refrigerant; and a water pump configured to selectively pump the water from the hot water heater through water pathway.

Systems, apparatus and methods for efficiently operating a chiller plant while minimizing or eliminating the occurrence of centrifugal compressor surge. Taking into account chiller design specifications and current operating conditions, a compressor lift point at which surge is predicted to occur is established. Minima and maxima for various chiller setpoints that avoid or eliminate the occurrence of compressor surge are imposed on setpoints provided by a conventional optimizing chiller controller. The chiller system is operated in accordance with the resultant anti-surge setpoints. Energy savings is realized by modulating coolant tower flow to enable the compressor to operate at near-surge conditions while preventing the onset of actual surge.

A refrigeration unit includes a compressor, a first heat exchanger, a second heat exchanger, a water pump, and a heat exchanging arrangement. The heat exchanging arrangement includes a main casing having a receiving cavity divided into a water atomizing compartment and one water showering compartment, a water atomizing unit, a water showering head, a fill material unit provided underneath the water showering head, and a water collection basin provided underneath the water atomizing unit and the fill material unit. A predetermined amount of heated water from the first heat exchanger is guided to flow to the water showering head and the water in the water showering head is sprinkled on the fill material unit. A predetermined amount of water from the water pump is guided to flow to the water atomizing unit and the water flowing to the water atomizing unit is sprayed and atomized in the water atomizing compartment.

A vapor compression system (20; 120; 220; 320) has: first (22A; 122A; 222A) and second (22B; 122B; 222B) compressors; first (40) and second (46) heat exchangers; and one or more expansion devices (52; 52A, 52B). Means (32A, 32B; 32A, 32B, 126A, 126B; 32A, 32B, 232A, 232B) are provided for switching the system between operation in first and second modes using the respective first and second compressors. In the first mode: the first compressor compresses refrigerant; the compressed refrigerant is cooled in the first heat exchanger; the cooled refrigerant is expanded in at least one of the one or more expansion devices; and the expanded refrigerant absorbs heat in the second heat exchanger. In the second mode: the second compressor compresses refrigerant; the compressed refrigerant is cooled in the second heat exchanger; the cooled refrigerant is expanded in at least one of the one or more expansion devices; and the expanded refrigerant absorbs heat in the first heat exchanger.

A multi-connected heat recovery air conditioning system and a control method thereof. The multi-connected heat recovery air conditioning system includes an indoor unit, an outdoor unit and a hydraulic module, wherein the outdoor unit comprises a compressor, an outdoor heat exchanger, a first four-way valve and a second four-way valve. The multi-connected heat recovery air conditioning system further comprises an indoor unit temperature unit, a water temperature unit, a high-pressure sensor and a low-pressure sensor. The indoor unit temperature unit is arranged in the indoor unit for detecting and obtaining the outlet temperature value of the indoor unit, the water temperature unit is arranged at a heat exchange water tank for detecting and obtaining water temperature, and the high-pressure sensor and the low-pressure sensor are arranged at the output end and the air return end of the compressor respectively.

A method of operating a chiller having a closed refrigerant loop including a compressor, a condenser and an evaporator. The refrigerant used in the loop defining a pressure-enthalpy curve representative of different phases (vapor, liquid and vapor, and liquid) of the refrigerant at different combinations of pressure and enthalpy. The loop defining a process cycle (compression, condensation, expansion, and evaporation) of the refrigerant during operation of the loop relative to the pressure-enthalpy curve of the refrigerant. The method including continuously operating the compressor when a segment of the process cycle corresponds to the refrigerant being in the liquid phase.

A hybrid heat pump system comprising a heat pump loop integrated with a hydronic loop. The hybrid heat pump system offers multiple modes of operation to provide increased versatility and improved performance. Each of the loops can operate independently. In addition, the loops can operate in conjunction with each other in both heating and cooling modes. Still further, the hydronic loop can provide a reheat function when the heat pump loop is operating in the cooling mode to provide improved dehumidification of the air delivered to the conditioned space. The heat pump loop may include a hot gas bypass functionality for capacity control and/or freeze protection. The hydronic heat exchanger and the space heat exchanger of the heat pump loop may be combined in a compact single slab construction with a slit fin preventing cross-conduction between the heat exchanger sections.

One embodiment of LMHPs, as shown in FIG. 10, is a multi-function, grid-interactive heat pump system by alternately charging/discharging thermal energy storage (40) as its heat pump source. The charging process maintains thermal stability to the source. The thermal stability of the source ensures high system performance, and this energy-storage-as-source and its effective use provide system operational versatility. Which takes the forms of availing the system-operation of dual heat sources (10 and 20) for heating application, demand-response management (48), grid-integrated water heating (46) as well as grid-integrated space heating and cooling (48). By transcending the limitations of individual, stand-alone, solar units and heat pump units, the grid-interactive heat pump system performs heating function better than all existing heat pump methods. LMHP principle is applicable to single-function, grid-interactive heat pump operation with similar benefits of high performance and demand-response management. Other embodiments are described and shown.

An air conditioning system can be toggled between a heating mode, in which heat is withdrawn from a source (e.g., a geothermal source) and deposited into a conditioned space (e.g., a building), and a cooling mode, in which heat is withdrawn from the conditioned space and deposited into the source. The air conditioning system uses a combination of efficiency-enhancing technologies, including injection of superheated vapor into the system's compressor from an economizer circuit, adjustable compressor speed, the use of one or coaxial heat exchangers and the use of electronic expansion valves that are continuously adjustable from a fully closed to various open positions. A controller may be used to control the system for optimal performance in both the heating and cooling modes, such as by disabling the economizer circuit and vapor injection when the system is in the cooling mode.

A device for heating by absorbing latent heat of solidification of water, including a compressor (1), a condenser (2) and multiple evaporators (E1, E2) connected in parallel, each evaporator (E1, E2) has an electronic expansion valve (D1, D2) at its inlet, a solenoid valve (V1, V2) at its outlet; after the evaporators (E1, E2) are connected in parallel, outlets of the evaporators (E1, E2) are connected to an inlet of the compressor (1) and inlets of the evaporators (E1, E2) are connected to an outlet of the condenser (2); an outlet of the compressor (1) is connected to an inlet of the condenser (2); the compressor (1), the condenser (2) and the multiple parallel evaporators (E1, E2) form a closed loop system through pipelines; there are circulating refrigerants in the closed loop system, and heating and deicing processes are realized through a circulation of refrigerants; the solenoid valves (V1, V2) at the outlets of the evaporators (E1, E2) are switched between opening or closing to realize switching between evaporating and deicing functions of the evaporators (E1, E2).