Heating and hot water supply apparatus and method of controlling the same

Patent metadata

Field	Value
Publication number	US-10969142-B2
Application number	US-201816033232-A
Country	US
Kind code	B2
Filing date	Jul 12, 2018
Priority date	Jul 27, 2017
Publication date	Apr 6, 2021
Grant date	Apr 6, 2021

Abstract

In a heating and hot water supply apparatus, a heat exchanger for hot water supply includes a primary-side path and a secondary-side path. A bypass path branches from a heating circulation path and is configured such that a heat transfer medium heated by a heating device flows through the primary-side path without passing through a heating terminal when hot water supply operation is performed and then joins the heating circulation path again. A control unit controls a flow rate regulating valve so that a hot water flow rate does not exceed a reference limit flow rate when hot water supply operation is performed. The reference limit flow rate is set on the basis of the smaller one between a maximum heating capacity of the heating device and a heating capacity of the heating device at which an output temperature of the heated heat transfer medium reaches an upper limit temperature.

First claim

What is claimed is:

1. A heating and hot water supply apparatus comprising:
a heating device configured to heat a heat transfer medium;
a heating circulation path for circulating the heat transfer medium heated by the heating device when a heating operation is performed to and from a heating terminal;
a heat exchanger for hot water supply including a primary-side path and a secondary-side path for heat exchange between liquids;
a bypass path which branches from the heating circulation path and through which the heat transfer medium flows through the primary-side path of the heat exchanger for hot water supply without passing through the heating terminal when a hot water supply operation is performed and then joins the heating circulation path again;
a water inlet pipe that is connected to an input side of the secondary-side path;
a hot water delivery pipe that is connected to an output side of the secondary-side path;
a flow rate regulating valve configured to control a hot water flow rate of the hot water delivery pipe; and
a control unit configured to control the flow rate regulating valve so that the hot water flow rate does not exceed a reference limit flow rate when the hot water supply operation is performed,
wherein the reference limit flow rate is set on the basis of the smaller one between a maximum heating capacity of the heating device and a heating capacity of the heating device at which an output temperature of the heated heat transfer medium reaches an upper limit temperature.

2. The heating and hot water supply apparatus according to claim 1 ,
wherein, when the hot water supply operation is performed, the control unit additionally reduces an amount of heat generated in the heating device when the output temperature of the heat transfer medium exceeds the upper limit temperature.

3. The heating and hot water supply apparatus according to claim 1 ,
wherein, when the hot water supply operation is performed, the control unit sets the smaller one between a first limit flow rate set on the basis of the maximum heating capacity of the heating device and a second limit flow rate set on the basis of a heating capacity of the heating device at which the output temperature of the heat transfer medium reaches the upper limit temperature as the reference limit flow rate, and controls the flow rate regulating valve so that the hot water flow rate does not exceed the reference limit flow rate.

4. The heating and hot water supply apparatus according to claim 2 ,
wherein, when the hot water supply operation is performed, the control unit sets the smaller one between a first limit flow rate set on the basis of the maximum heating capacity of the heating device and a second limit flow rate set on the basis of a heating capacity of the heating device at which the output temperature of the heat transfer medium reaches the upper limit temperature as the reference limit flow rate, and controls the flow rate regulating valve so that the hot water flow rate does not exceed the reference limit flow rate.

5. The heating and hot water supply apparatus according to claim 3 , further comprising
a first temperature sensor configured to detect an inlet water temperature of low temperature water introduced into the water inlet pipe; and
a second temperature sensor configured to detect an input temperature of the heat transfer medium in the heating device,
wherein the first limit flow rate is set on the basis of the maximum heating capacity, a hot water supply set temperature in the hot water supply operation, and a temperature detected by the first temperature sensor, and
wherein the second limit flow rate is set on the basis of the upper limit temperature of the heat transfer medium, a temperature detected by the second temperature sensor, a flow rate of the heat transfer medium that flows through the heating device, the hot water supply set temperature, and the temperature detected by the first temperature sensor.

6. The heating and hot water supply apparatus according to claim 4 , further comprising
a first temperature sensor configured to detect an inlet water temperature of low temperature water introduced into the water inlet pipe; and
a second temperature sensor configured to detect an input temperature of the heat transfer medium in the heating device,
wherein the first limit flow rate is set on the basis of the maximum heating capacity, a hot water supply set temperature in the hot water supply operation, and a temperature detected by the first temperature sensor, and
wherein the second limit flow rate is set on the basis of the upper limit temperature of the heat transfer medium, a temperature detected by the second temperature sensor, a flow rate of the heat transfer medium that flows through the heating device, the hot water supply set temperature, and the temperature detected by the first temperature sensor.

7. The heating and hot water supply apparatus according to claim 5 , further comprising
a third temperature sensor configured to detect a hot water temperature of the hot water delivery pipe,
wherein the control unit corrects the reference limit flow rate on the basis of a deviation of a temperature detected by the third temperature sensor with respect to the hot water supply set temperature.

8. The heating and hot water supply apparatus according to claim 6 , further comprising
a third temperature sensor configured to detect a hot water temperature of the hot water delivery pipe,
wherein the control unit corrects the reference limit flow rate on the basis of a deviation of a temperature detected by the third temperature sensor with respect to the hot water supply set temperature.

9. The heating and hot water supply apparatus according to claim 7 ,
wherein the control unit corrects the reference limit flow rate so that the reference limit flow rate decreases when the deviation of the temperature detected by the third temperature sensor with respect to the hot water supply set temperature increases.

10. The heating and hot water supply apparatus according to claim 8 ,
wherein the control unit corrects the reference limit flow rate so that the reference limit flow rate decreases when the deviation of the temperature detected by the third temperature sensor with respect to the hot water supply set temperature increases.

11. The heating and hot water supply apparatus according to claim 7 , further comprising
a bypass pipe which branches from the water inlet pipe and through which the low temperature water joins the hot water delivery pipe without passing through the secondary-side path;
a bypass flow rate valve configured to control a flow rate ratio of the bypass pipe with respect to a flow rate of water input to the water inlet pipe; and
a fourth temperature sensor configured to detect a temperature of high temperature water output from the secondary-side path to the hot water delivery pipe,
wherein the control unit calculates a target temperature of the high temperature water on the basis of a flow rate ratio in the bypass flow rate valve, a temperature detected by the first temperature sensor and the hot water supply set temperature, and corrects the reference limit flow rate on the basis of a deviation of the temperature detected by the fourth temperature sensor with respect to the target temperature of the high temperature water and a deviation of the temperature detected by the third temperature sensor with respect to the hot water supply set temperature.

12. The heating and hot water supply apparatus according to claim 8 , further comprising
a bypass pipe which branches from the water inlet pipe and through which the low temperature w

Assignees

• Noritz Corp

Inventors

• Tsuda Naoki
• Atobe Yoshifumi
• Nakayama Kenichi

Classifications

• F24H9/139

  Continuous flow heaters · CPC title

• F24H1/52

  incorporating heat exchangers for domestic water (F24H1/50 takes precedence) · CPC title

• F24H1/145

  using fluid fuel · CPC title

• F24H9/1836

  using fluid fuel · CPC title

• F24H8/006

  Means for removing condensate from the heater · CPC title