water heating system

Abstract

Feedwater to be supplied to a feedwater tank via a feedwater path is passed through a waste heat recovery heat exchanger, a supercooler, and a condenser in sequence. A heat source fluid such as heat source water is passed through an evaporator and the waste heat recovery heat exchanger in sequence. The waste heat recovery heat exchanger is an indirect heat exchanger between the feedwater supplied to the feedwater tank via the feedwater path and the heat source fluid having passed through the evaporator. The supercooler is an indirect heat exchanger between the feedwater supplied to the feedwater tank via the feedwater path and a refrigerant supplied from the condenser to an expansion valve.

Description

technical field [0001] The invention relates to a water supply heating system using a heat pump. this application claims priority based on Japanese Patent Application No. 2012-079191 for which it applied to Japan on March 30, 2012, and uses the content here. Background technique [0002] Conventionally, as disclosed in Patent Document 1 below, there is known a system capable of heating water supplied to a water supply tank (23) of a boiler (24) using a heat pump (12). In addition, as disclosed in the following Patent Document 2, it is also known that a system (S1) for generating steam using a heat pump (10) is divided into a heating section (21 (first heat exchange unit) for heating water until it approaches boiling point). device 40)) and the evaporation part (22 (second heat exchanger 41)) that evaporates water. [0003] prior art literature [0004] patent documents [0005] Patent Document 1: Japanese Unexamined Patent Publication No. 2010-25431 (FIG. 2, FIG. 3) [...

AI Technical Summary

Problems solved by technology

[0008] In the inventions described in the above-mentioned patent documents, there is still available heat remaining in the heat source fluid after passing through the evaporator of the heat pump, and it cannot be utilized.

In addition, if the heat pump bears all the heating of the supplied water, the system will be enlarged, the power consumption of the compressor will also increase, and the efficiency (coefficient of performance COP) of the heat pump will be poor.

[0009] In addition, in the inventions described in the above-mentioned patent documents, the flow rate of the water heated by the heat pump is intended to be constant. Therefore, it is impossible to adjust the flow rate of the water from the heat pump to the water temperature of the water supply source and the temperature change of the heat source fluid leading to the evaporator of the heat pump. The gushing temperature of hot water (in the invention described in Patent Document 2, since the evaporating part 22 becomes the saturation temperature under a predetermined pressure, it is equivalent to the temperature of the water heated by the heating part 21) is maintained at a desired temperature

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