Hot water supply apparatus

Patent metadata

Field	Value
Publication number	US-11739950-B2
Application number	US-201816964238-A
Country	US
Kind code	B2
Filing date	Feb 23, 2018
Priority date	Feb 23, 2018
Publication date	Aug 29, 2023
Grant date	Aug 29, 2023

Abstract

A hot water supply apparatus includes a heat pump device in which a compressor and a heat exchanger are connected, a heat medium circuit connected to the heat pump device via the heat exchanger, a tank that stores water after the water exchanges heat with a heat medium of the heat medium circuit, two tank-temperature detection units attached at different heights to the tank and each detects a temperature of water in the tank, and a controller that controls, by using a value detected by each of the two tank-temperature detection units, a temperature of water in the tank. The controller sets a target hot water supply temperature based on a stored-hot-water temperature detected by one of the two tank temperature detection units and a within-tank temperature difference that is a difference between temperatures within the tank detected by the two tank-temperature detection units.

First claim

The invention claimed is:

1. A hot water supply apparatus, comprising:
a heat pump device in which a compressor and a heat exchanger are connected;
a heat medium circuit connected to the heat pump device via the heat exchanger;
a tank configured to store water after the water exchanges heat with a heat medium of the heat medium circuit;
two tank-temperature sensors attached at different heights to the tank, the two tank-temperature sensors each being configured to detect a temperature of water in the tank; and
a controller configured to, by using a value detected by each of the two tank-temperature sensors, control a temperature of water in the tank,
wherein the controller sets a target hot water supply temperature based on a stored-hot-water temperature and a comparison of a within-tank temperature difference with a first threshold, the target hot water supply temperature being a target temperature at which water in the tank is to be supplied as hot water, the stored-hot-water temperature being a temperature of stored hot water represented by a value detected by one of the two tank-temperature sensors selected by a user, the within-tank temperature difference being a difference between temperatures within the tank individually detected by the two tank-temperature sensors.

2. The hot water supply apparatus of claim 1 ,
wherein if the stored-hot-water temperature is higher than or equal to the first threshold, and the within-tank temperature difference is less than a second threshold, the controller sets the target hot water supply temperature to a temperature lower than the stored-hot-water temperature.

3. The hot water supply apparatus of claim 1 ,
wherein if the stored-hot-water temperature is higher than or equal to the first threshold, and the within-tank temperature difference is less than a second threshold, the controller sets a rotation speed of the compressor to a rotation speed that maximizes operating efficiency.

4. The hot water supply apparatus of claim 1 ,
wherein if the stored-hot-water temperature is lower than the first threshold, or if the within-tank temperature difference is greater than or equal to a second threshold, the controller sets the target hot water supply temperature to a preset hot water supply temperature.

5. The hot water supply apparatus of claim 1 ,
wherein the heat medium circuit includes a tank-side heat exchanger in which a heat medium and water in the tank exchange heat, and
wherein the tank-side heat exchanger is disposed inside the tank.

6. The hot water supply apparatus of claim 1 , further comprising a heating unit, the heating unit being connected to the heat medium circuit and configured to reject heat to an air-conditioned space.

7. The hot water supply apparatus of claim 1 , wherein:
the first threshold is a first temperature threshold, and
the controller is further configured to set the target hot water supply temperature based on the within-tank temperature difference being compared to a second temperature threshold.

Assignees

• Mitsubishi Electric Corp

Inventors

• Yoshida Jun
• Takayama Keisuke

Classifications

• F24H15/38

  Control of compressors of heat pumps · CPC title

• F24D17/02 Primary

  using heat pumps · CPC title

• F24H1/18

  Water-storage heaters · CPC title

• F24H4/04 Primary

  Storage heaters · CPC title

• F24D2200/123

  Compression type heat pumps · CPC title