Thermoacoustic engine

A thermoacoustic engine, comprising:

• a looped tube filled with a gas;
• a first stack and a second stack disposed in the looped tube,
• wherein the first stack has a first end to which heat is inputted and a second end opposite to the first end and to which cooling water is inputted,
• wherein the second stack has a first end to which the cooling water having passed through the second end of the first stack is inputted and a second end opposite to the first end and provided with a cooling device,
• wherein the first stack comprises a first stack element disposed between a first hot side heat exchanger and a first cold side heat exchanger, the first hot side heat exchanger constituting the first end of the first stack and the first cold side heat exchanger constituting the second end of the first stack,
• wherein the second stack comprises a second stack element disposed between a second hot side heat exchanger and a second cold side heat exchanger, the second hot side heat exchanger constituting the first end of the second stack and the second cold side heat exchanger constituting the second end of the second stack, and
• wherein the first hot side heat exchanger constituting the first end of the first stack and the second hot side heat exchanger constituting the first end of the second stack are opposed to each other;
• a cooling water passage for guiding the cooling water to the first cool side heat exchanger constituting the second end of the first stack;
• a flow controller disposed on the cooling water passage for controlling the flow rate of the cooling water;
• and
• a hot water passage connecting the first cold side heat exchanger of the first stack and the second hot side heat exchanger of the second stack and guiding the cooling water from the first cold side heat exchanger to the second hot side heat exchanger such that the cooling water supplied to the first cold side heat exchanger of the first stack is heated by heat released from the first cold side heat exchanger of the first stack and the thus heated cooling water is subsequently guided to the second hot side heat exchanger and reheated by heat released from the second hot side heat exchanger of the second stack,
• wherein the flow controller regulates the flow rate of the cooling water flowing successively through the cooling water passage and the hot water passage to raise or lower temperatures of the first cool side heat exchanger and the second hot side heat exchanger to maintain a condition that a first ratio of a temperature of the first end of the first stack to a temperature of the second end of the first stack is equal to a second ratio of a temperature of the first end of the second stack to a temperature of the second end of the second stack.