Arrangement and method for converting thermal energy to mechanical energy

摘要

An arrangement and a method for converting thermal energy to mechanical energy. The arrangement has a line circuit (3), circulation device (4) for circulating a zeotropic refrigerant mixture in the line circuit (3), an evaporator (6) in which the refrigerant mixture is vaporized by a heat source (7), a turbine (9) driven by the vaporized refrigerant mixture, and a condenser (12) which cools the refrigerant mixture so that it condenses. A control unit assesses whether the refrigerant mixture does not become fully vaporized in the evaporator (6) and, leads incompletely vaporized refrigerant mixture leaving the evaporator to a separating device (14) in which a liquid portion of the refrigerant mixture is separated from the gaseous portion, after which only the gaseous portion proceeds towards the turbine (9).

主权项

1. An arrangement for converting thermal energy to mechanical energy, the arrangement comprising:
a line circuit; a pump configured for circulating a zeotropic refrigerant mixture in the line circuit; the zeotropic refrigerant mixture comprises a first refrigerant and a second refrigerant, wherein the first refrigerant has a higher vaporisation temperature than the second refrigerant at a similar pressure; an evaporator to which the refrigerant mixture is circulated and where the mixture is vaporised and a heat source for the evaporator and operative for vaporizing the refrigerant mixture; a turbine in the line circuit and located and configured to be driven by the vaporised refrigerant mixture; a condenser in which the refrigerant mixture is cooled so that the vaporised refrigerant mixture condenses; an electronic control unit configured for assessing whether the refrigerant mixture does not become fully vaporised at the evaporator and, when the control unit assesses that the refrigerant mixture is not fully vaporised, the control unit is configured to put the arrangement into a low-effect state, the low-effect state comprising the arrangement leading the incompletely vaporised refrigerant mixture through a first conduit leaving the evaporator; a gas/liquid separating device connected with the first conduit from the evaporator configured for separating a first portion of the refrigerant mixture, which is in liquid form, from a second portion of the refrigerant mixture, which is in gaseous form, wherein the separated liquid refrigerant mixture is prevented from leaving the separating device when the arrangement is in the low-effect state; and a second conduit for transmitting the gaseous portion of the refrigerant mixture from the separating device toward the turbine in the line circuit and when a temperature of the heat source rises back to a higher temperature, the control unit being configured to put the arrangement into a high-effect state, the high-effect state comprising the arrangement leading the separated liquid refrigerant mixture back to the line circuit, wherein the control unit is configured and operable to lead the refrigerant mixture from the evaporator towards the turbine through an ordinary line section of the line circuit bypassing the separating device when the control unit assesses that the arrangement is in the high-effect state, and through an extra line section of the line circuit which contains the separating device when the control unit assesses that the arrangement is in the low-effect state.