US 5,632,442 AGranted

Engine-driven heat pump apparatus and method for stable operation of heat pump

AssigneeYamaha Hatsudoki Kabushiki Kaisha

InventorsMakoto Misawa, Makoto Oguri

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Abstract

An engine-driven heat pump apparatus having a refrigerant circulation line which includes a pressure-measuring device for measuring the pressure in the refrigerant circulation line downstream of a compressor and upstream of an expansion valve, and an exhaust heat controller for controlling the exhaust heat from the engine based on the pressure by, for example, changing the heat efficiency of the engine, e.g., by controlling at least one of (a) the ignition timing of the engine, (b) the opening and closing timing of an intake port valve and an exhaust port valve, and (c) the opening of a fuel gas-controlling valve, so as to efficiently increase heating power during heating operation at low temperatures, without increasing engine noise or shortening the life of the engine.

Claims13

Dependent claims

An engine-driven heat pump apparatus comprising a refrigerant circulation line through which a refrigerant circulates, said refrigerant circulation line comprising:

an engine-driven compressor for circulating said refrigerant;
a cooling water circulation line through which a cooling water for cooling said engine circulates;
a cooling water-exhaust heat heat-exchanger for exchanging heat between said cooling water and exhaust heat from said engine;
a cooling water-refrigerant heat-exchanger for exchanging heat between said cooling water and said refrigerant;
an inside heat-exchanger for exchanging heat between said refrigerant and the air inside a room;
an outside heat-exchanger for exchanging heat between said refrigerant and the air outside said room;
an expansion valve arranged in series with said inside heat-exchanger;
a four-way valve for reversing the flow of said refrigerant at said inside heat-exchanger and at said outside heat-exchanger;
a pressure-measuring device for measuring the pressure in said refrigerant circulation line downstream of said compressor and upstream of said expansion valve;
and an exhaust heat controller for controlling exhaust heat from said engine based on the pressure measured by said pressure-measuring device so as to adjust the temperature of said cooling water via said cooling water-exhaust heat heat-exchanger.

7 more elements

A method for stable operation of a heat pump apparatus comprising, in a refrigerant circulation line through which a refrigerant circulates, an engine-driven compressor for circulating said refrigerant;

a cooling water circulation line through which a cooling water for cooling said engine circulates;
an inside heat-exchanger for exchanging heat between said refrigerant and the air inside a room;
an outside heat-exchanger for exchanging heat between said refrigerant and the air outside said room;
and an expansion valve arranged in series with said inside heat-exchanger;
a four-way valve for reversing the flow of said refrigerant at said inside heat-exchanger and at said outside heat-exchanger,
said method comprising the steps of:
measuring the pressure in said refrigerant circulation line downstream of said compressor and upstream of said expansion valve;
controlling exhaust heat from said engine based on said measured pressure, thereby adjusting the temperature of said cooling water;
and exchanging heat between said cooling water and said refrigerant, thereby adjusting the conditions of said refrigerant which enters said compressor.

6 more elements

Dependencies are inferred from the claim text.