COMBINED AIR-CONDITIONING AND HOT-WATER SUPPLY SYSTEM

• US 20130213072A1
• Filed: 12/15/2010
• Published: 08/22/2013
• Est. Priority Date: 12/15/2010
• Status: Active Grant

• Current Assignee: Mitsubishi Electric Corporation
• Original Assignee: Mitsubishi Electric Corporation
• Inventors: Kawagoe, Tomokazu, Koge, Hirofumi
• Granted Patent: US 9,625,187 B2
• Time in Patent Office: Days
• US Class Current: 62/238.6
• CPC Class Codes: F25B 13/00 Compression machines, plants or systems, with reversible cycle defrosting cycles F25B47/02
• CPC Class Codes: F25B 2313/003 Indoor unit with water as a heat sink or heat source
• CPC Class Codes: F25B 2313/02334 during heating
• CPC Class Codes: F25B 2313/02741 using one four-way valve
• CPC Class Codes: F25B 2500/27 characterised by the stop of the refrigeration cycle
• CPC Class Codes: F25B 2600/0253 with variable speed
• CPC Class Codes: F25B 2600/23 Time delays
• CPC Class Codes: F25B 2600/2513 Expansion valves
• CPC Class Codes: F25B 30/02 of the compression type
• CPC Class Codes: F25B 49/027 Condenser control arrangements
• CPC Class Codes: Y02B 30/70 Efficient control or regulation technologies, e.g. for control of refrigerant flow, motor or heating

Abstract

A combined air-conditioning and hot-water supply system that, if a temperature that is set in a hot-water supply unit is higher than a temperature of refrigerant discharged from a compressor when the combined air-conditioning and hot-water supply system is in a heating operation cycle state, increases a target condensing temperature of an outdoor unit above the target condensing temperature that has been set, and controls an opening degree of an indoor expansion device to be less than the opening degree that has been set, such that a heating load of an indoor unit is maintained constant.

Claims

1. A combined air-conditioning and hot-water supply system comprising:

at least one outdoor unit including a compressor and an outdoor heat exchanger;

at least one indoor unit connected to the outdoor unit, the indoor unit including an indoor heat exchanger and an indoor expansion device; and

at least one hot-water supply unit connected to the outdoor unit so as to be arranged in parallel to the indoor unit, the hot-water supply unit including a refrigerant-to-water heat exchanger and a hot-water-supply-side expansion device,

the combined air-conditioning and hot-water supply system being operated so as to achieve a target condensing temperature that is set in the outdoor unit,

wherein, when the indoor unit performs a heating operation and the hot-water supply unit performs a hot-water supply operation, if a temperature that is set in the hot-water supply unit is higher than a temperature of refrigerant discharged from the compressor, the target condensing temperature of the outdoor unit is increased above the target condensing temperature that has been set, and an opening degree of the indoor expansion device is controlled to be less than the opening degree that has been set, such that a heating load of the indoor unit is maintained constant.

2. The combined air-conditioning and hot-water supply system of claim 1, wherein, upon individually stopping the indoor unit or the hot-water supply unit, a frequency of the compressor is reduced below a current frequency before stopping the indoor unit or the hot-water supply unit to be stopped, and then the indoor unit or the hot-water supply unit to be stopped is stopped.

3. The combined air-conditioning and hot-water supply system of claim 2, wherein the indoor unit or the hot-water supply unit to be stopped is stopped after information indicating a completion of an operation of reducing the frequency of the compressor below the current frequency is received from the outdoor unit.

4. The combined air-conditioning and hot-water supply system of claim 2, wherein the indoor unit or the hot-water supply unit to be stopped is stopped after a lapse of a time period equal to or greater than a time period taken to complete an operation of reducing the frequency of the compressor below the current frequency.

5. The combined air-conditioning and hot-water supply system of claim 1, wherein a temperature of water flowing out of the refrigerant-to-water heat exchanger is adjusted to be constant by controlling an opening degree of the hot-water-supply-side expansion device.