Hot gas machine

Claim 1

A cyclically operating hot gas machine including: a working fluid; expander means for cyclic expansion of said working fluid, said expander means having an expansion space with a fluid inlet and a fluid outlet and operating means in said expansion space for cyclic expansion of said working fluid; compressor means for cyclic compression of said working fluid, said compressor means having a compression space with a fluid inlet and a fluid outlet and operAting means in said compression space for cyclic compression of said working fluid; first fluid circuit means in said hot gas machine, said first fluid circuit means being a closed circuit containing said working fluid, said expansion space and said compression space being in said closed fluid circuit, a first part of said closed fluid circuit extending from the outlet of said expansion space to the inlet of said compression space, and a second part of said closed fluid circuit extending from the outlet of said compression space to the inlet of said expansion space; first counterflow heat exchanger means in said first part of said closed fluid circuit; second counterflow heat exchanger means in said second part of said closed fluid circuit; second fluid circuit means in said hot gas machine, said second fluid circuit means being connected in series to each of said first and second counterflow heat exchanger means and having a heat exchange fluid flowing therein, the direction of flow of said heat exchange fluid in said second fluid circuit means and said working fluid in said first fluid circuit means being opposite to provide counterflow heat exchange between said fluids; heat source means in said second fluid circuit means; cold source means in said second fluid circuit means; one of said heat or cold source means being in said second fluid circuit means between said first and second counterflow heat exchangers; said expander means and said compressor means cooperating during one part of the operating cycle of the hot gas machine to transfer working fluid from one of said expansion and compression spaces to the other of said spaces through one of said counterflow heat exchangers whereby heat is transferred from said heat exchange fluid to said working fluid to increase the pressure of said working fluid at substantially constant volume of said working fluid, and said expander means and said compressor means cooperating during another part of the operating cycle of the hot gas machine to transfer working fluid from the other of said expansion and compression spaces to said one of said spaces through the other of said counterflow heat exchangers whereby heat is transferred from said working fluid to said heat exchange fluid to reduce the pressure of said working fluid at a substantially constant volume of said working fluid; and check valve means in each of said first and second parts of said first fluid circuit to permit fluid to flow only in one direction serially through said parts of said first fluid circuit to limit the direction of flow of said working fluid in said first fluid circuit to the direction required to effect counterflow heat exchange between said working fluid and said heat exchange fluid in said first and second counterflow heat exchangers.

Claim 9

A method of operating a hot gas machine including the steps of: circulating a working fluid in a first closed circuit in a working cycle which includes serially: cyclically expanding the working fluid in cyclically operating expander means; passing the working fluid through a first counterflow heat exchanger by cooperating action of said expander and a compressor means; cyclically compressing the working fluid in cyclically operating compressor means; and passing the working fluid through a second counterflow heat exchanger by cooperating action of said expander and compressor means; circulating a heat transfer fluid in a second fluid circuit in a cycle which includes: passing said heat transfer fluid from a heat source to a cold source, said heat transfer fluid being passed through one of said counterflow heat exchangers in passing from said heat source to said cold source to increase the pressure of said working fluid at a substantially constant volume of said working fluid; and passing said heat transfer fluid from a cold source to a heat source, said heat transfer fluid being passed through the other of said counterflow heat exchangers in passing from said cold source to said heat source to reduce the pressure of said working fluid at a substantially constant volume of said working fluid; said working fluid and said heat transfer fluid being in counterflow heat exchange in each of said first and second heat exchangers to cool said working fluid and heat said heat transfer fluid in said other of said heat exchangers and heat said working fluid and cool said heat transfer fluid in said one of said heat exchangers; reducing the temperature of said heat transfer fluid at said cold source; increasing the temperature of said heat transfer fluid at said heat source; and limiting the direction of flow of said working fluid to a chosen direction in said first closed circuit.

Claim 10

A method of operating a hot gas machine including the steps of: circulating a working fluid in a first closed circuit in a working cycle which includes serially: cyclically expanding the working fluid in cyclically operating expander means; passing the working fluid through a first counterflow heat exchanger by cooperating action of said expander and a compressor means; cyclically compressing the working fluid in cyclically operating compressor means; and passing the working fluid through a second counterflow heat exchanger by cooperating action of said expander and compressor means; circulating a heat transfer fluid in a second fluid circuit in a cycle which includes: passing said heat transfer fluid from a heat source to a cold source, said heat transfer fluid being passed through one of said counterflow heat exchangers in passing from said heat source to said cold source to increase the pressure of said working fluid at a substantially constant volume of said working fluid; and passing said heat transfer fluid from a cold source to a heat source, said heat transfer fluid being passed through the other of said counterflow heat exchangers in passing from said cold source to said heat source to reduce the pressure of said working fluid at a substantially constant volume of said working fluid; said working fluid and said heat transfer fluid being in counterflow heat exchange in each of said first and second heat exchangers to cool said working fluid and heat said heat transfer fluid in said other of said heat exchangers and heat said working fluid and cool said heat transfer fluid in said one of said heat exchangers; reducing the temperature of said heat transfer fluid at said cold source; increasing the temperature of said heat transfer fluid at said heat source; and limiting the direction of flow of said working fluid to a chosen direction in said first closed circuit.