HEAT PUMP HOT-WATER SUPPLY SYSTEM

• US 20120205456A1
• Filed: 08/30/2010
• Published: 08/16/2012
• Est. Priority Date: 09/28/2009
• Status: Active Grant

• Current Assignee: Panasonic Intellectual Property Management Co., Ltd. (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Honma, Masaya, Kobayasi, Susumu
• Granted Patent: US 9,557,068 B2
• Time in Patent Office: Days
• US Class Current: 237/2.B
• CPC Class Codes: F24D 18/00 Small-scale combined heat and power [CHP] generation systems specially adapted for domestic heating, space heating or domestic hot-water supply
• CPC Class Codes: F24D 19/106 the system uses a heat pump and solar energy
• CPC Class Codes: F24D 19/1063 counting of energy consumption
• CPC Class Codes: F24D 2101/40 Photovoltaic [PV] modules
• CPC Class Codes: F24D 2200/02 Photovoltaic energy
• CPC Class Codes: F24D 2200/12 Heat pump
• CPC Class Codes: F24D 2200/14 Solar energy
• CPC Class Codes: F24D 2220/08 Storage tanks
• CPC Class Codes: F24H 2240/01 Batteries, electrical energy storage device
• CPC Class Codes: G05D 23/1923 using thermal energy, the cost of which varies in function of time
• CPC Class Codes: Y02B 10/20 Solar thermal
• CPC Class Codes: Y02B 10/70 Hybrid systems, e.g. uninterruptible or back-up power supplies integrating renewable energies

Abstract

A heat pump hot-water supply system includes a heat pump hot-water supply device, an electricity storage device, and a control device. The control device determines an operating time zone of the heat pump hot-water supply device based on power conversion efficiency of the electricity storage device, coefficients of performance of the heat pump hot-water supply device of a current day and a next day, and an electricity rate structure of a commercial power system.

Claims

1. A heat pump hot-water supply system, comprising a heat pump hot-water supply device, an electricity storage device, and a control device,

wherein the control device determines an operating time zone of the heat pump hot-water supply device based on power conversion efficiency of the electricity storage device, coefficients of performance of the heat pump hot-water supply device of a current day and a next day, and an electricity rate structure of a commercial power system.

2. The heat pump hot-water supply system of claim 1, further comprising a hot-water storage tank for storing hot water obtained by operating the heat pump hot-water supply device, wherein the electricity storage device converts an AC power supplied from the commercial power system into a DC power to store the DC power and also convert the stored DC power into an AC power to supply the AC power, and the control device further determines whether the electricity storage device is to be charged or not based on the power conversion efficiency of the electricity storage device, the coefficients of performance of the heat pump hot-water supply device of the current day and the next day, and the electricity rate structure of the commercial power system.

3. The heat pump hot-water supply system of claim 2, wherein the control device performs a control operation in such a manner that, in accordance with the electricity rate structure wherein a nighttime electricity rate is lower than a daytime electricity rate, a ratio of coefficients of performance obtained by dividing a coefficient of performance of the heat pump hot-water supply device corresponding to an outside air temperature of the nighttime of the current day by a coefficient of performance of the heat pump hot-water supply device corresponding to an estimated value of an outside air temperature of the daytime of the next day is compared with the power conversion efficiency of the electricity storage device, and thus the heat pump hot-water supply device is operated in the daytime of the next day by using power stored in the electricity storage device in the nighttime of the current day if the ratio of coefficients of performance is less than the power conversion efficiency, whereas the heat pump hot-water supply device is operated in the nighttime of the current day by using power supplied from the commercial power system if the ratio of coefficients of performance is equal to or greater than the power conversion efficiency.

4. A heat pump hot-water supply system, comprising a heat pump hot-water supply device, an electricity storage device, a solar light power generation device for generating power by using solar light, and a control device,

wherein the control device compares an estimated amount of power to be generated by the solar light power generation device on a next day with an estimated amount of power required of the heat pump hot-water supply device on the next day, and thus controls operation of the heat pump hot-water supply device by using power supplied from a commercial power system in a nighttime.

5. The heat pump hot-water supply system of claim 4, further comprising a hot-water storage tank for storing hot water obtained by operating the heat pump hot-water supply device, wherein the electricity storage device converts an AC power supplied from the commercial power system into a DC power to store the DC power and also convert the stored DC power into an AC power to supply the AC power, and the control device performs a control operation in such a manner that the amount of power to be generated by the solar light power generation device on the next day and a power demand of other electric devices than the heat pump hot-water supply device are estimated and also a power surplus obtained by subtracting the power demand from the amount of power to be generated is compared with the amount of power required of the heat pump hot-water supply device on the next day, and thus an amount corresponding to a deficit in the amount of power required which cannot be supplemented by the power surplus is stored in the electricity storage device during the nighttime of a current day, or the heat pump hot-water supply device is operated in the nighttime of the current day to generate as much power as the deficit in the amount of power required.

6. A heat pump hot-water supply system, comprising a heat pump hot-water supply device, a solar heat-assisted water heater, an electricity storage device, and a control device,

wherein the control device estimates an amount of hot water required on a next day and an amount of hot water to be supplied from the solar heat-assisted water heater on the next day, and thus controls whether the electricity storage device is to be charged or not.

7. The heat pump hot-water supply system of claim 6, further comprising a hot-water storage tank for storing hot water obtained by operating the heat pump hot-water supply device and hot water obtained by operating the solar heat-assisted water heater, wherein the electricity storage device converts an AC power supplied from a commercial power system into a DC power to store the DC power and also convert the stored DC power into an AC power to supply the AC power, and the control device performs a control operation in such a manner that the amount of hot water required on the next day and the amount of hot water to be supplied from the solar heat-assisted water heater on the next day are estimated, and if the amount of hot water to be supplied is deficient compared to the amount of hot water required, in order to make up for a deficit in the amount of hot water, power required of the heat pump hot-water supply device is stored in the electricity storage device in the a nighttime of a current day and the heat pump hot-water supply device is operated in the daytime of the next day by using the power stored in the electricity storage device.