Heat exchanger

1. A heat exchanger, comprising:

an evaporator for receiving a heat load, the evaporator including a pair of base plates, each base plate having a first surface with channels extending from a manifold at a first end of the evaporator to a manifold at a second end of the evaporator, some of the channels are embedded into the base plate and some of the channels are arranged outside of the base plate, the pair of base plates of the evaporator are arranged with their respective first surfaces towards each other;

a condenser for passing a heat load to surroundings, the condenser including channels extending from a manifold at a first end of the condenser to a manifold at a second end of the condenser;

pipes connecting the evaporator and condenser to each other in order to pass fluid between the evaporator and condenser;

at least one riser pipe connecting the manifold at the second end of the evaporator to the manifold at the second end of the condenser; and

at least one return pipe connecting the manifold at the first end of the condenser to the manifold at the first end of the evaporator; and

wherein at least the first or second end of the evaporator comprises a manifold including two separate tubes, each interconnecting ends of the channels of one base plate to each other, the tubes are connected to each other by communication ports allowing fluid communication between the tubes.

2. The heat exchanger according to claim 1 , wherein at least one of the evaporator and condenser has channels of a capillary dimension.

3. The heat exchanger according to claim 1 , wherein the channels of the respective first surfaces of the pair of base plates are arranged into pipes whose internal walls separate the channels from each other, the pipes partly penetrating into the first surface of the base plate.

4. The heat exchanger according to claim 1 , wherein the manifold at the second end of the evaporator is located at a higher level than the manifold at the first end of the evaporator, and the manifold at the second end of the condenser is located at a higher level than the manifold at the first end of the condenser.

5. The heat exchanger according to claim 1 , comprising:

a cooling gas or liquid for passing between channels of the condenser.

6. The heat exchanger according to claim 1 , wherein

in the evaporator, the manifold at the second end is located higher than the manifold at the first end, some of the channels are evaporation channels embedded into the base plates and some of the channels are arranged outside of the base plates to provide a return path for non-vaporized liquid that comes out of the evaporation channels;

the manifold at the second end of the condenser is higher located than the manifold at the first end; and

the manifold at the first end of the condenser is located at a higher level than the manifold at the second end of the evaporator.

7. A heat exchanger, comprising:

an evaporator for receiving a heat load, the evaporator including a pair of base plates, each base plate having a first surface with channels extending from a manifold at a first end of the evaporator to a manifold at a second end of the evaporator, some of the channels are embedded into the base plate and some of the channels are arranged outside of the base plate, the pair of base plates of the evaporator are arranged with their respective first surfaces towards each other;

a condenser for passing a heat load to surroundings, the condenser including channels extending from a manifold at a first end of the condenser to a manifold at a second end of the condenser;

pipes connecting the evaporator and condenser to each other in order to pass fluid between the evaporator and condenser;

at least one riser pipe connecting the manifold at the second end of the evaporator to the manifold at the second end of the condenser; and

at least one return pipe connecting the manifold at the first end of the condenser to the manifold at the first end of the evaporator, and wherein

the channels of the condenser are arranged into pipes whose internal and external walls separate the channels from each other, and

the condenser comprises at least two rows of pipes whose internal and external walls separate channels from each other, at least the first or second end of the condenser comprises a manifold including two separate tubes, each interconnecting the channels of one row of pipes to each other, the tubes being connected to each other by communication ports for allowing fluid communication between the tubes.

8. The heat exchanger according to claim 7 , wherein the condenser comprises:

fins extending between walls of the pipes.

9. The heat exchanger according to claim 8 , wherein the condenser comprises:

at least two rows of pipes whose internal and external walls separate channels from each other, at least the first or second end of the condenser comprises a manifold including two separate tubes, each interconnecting the channels of one row of pipes to each other, the tubes being connected to each other by communication ports for allowing fluid communication between the tubes.

10. A heat exchanger, comprising:

an evaporator for receiving a heat load, the evaporator including a pair of base plates, each base plate having a first surface with channels extending from a manifold at a first end of the evaporator to a manifold at a second end of the evaporator, some of the channels are embedded into the base plate and some of the channels are arranged outside of the base plate, the pair of base plates of the evaporator are arranged with their respective first surfaces towards each other;

a condenser for passing a heat load to surroundings, the condenser including channels extending from a manifold at a first end of the condenser to a manifold at a second end of the condenser;

pipes connecting the evaporator and condenser to each other in order to pass fluid between the evaporator and condenser;

at least one riser pipe connecting the manifold at the second end of the evaporator to the manifold at the second end of the condenser;

at least one return pipe connecting the manifold at the first end of the condenser to the manifold at the first end of the evaporator;

two riser pipes connecting opposite ends of the manifold at the second end of the evaporator to the opposite ends of the manifold at the second end of the condenser; and

two return pipes connecting opposite ends of the manifold at the first end of the condenser to opposite ends of the manifold at the first end of the evaporator.

11. A heat exchanger, comprising:

an evaporator for receiving a heat load, the evaporator including a pair of base plates, each base plate having a first surface with channels extending from a manifold at a first end of the evaporator to a manifold at a second end of the evaporator, some of the channels are embedded into the base plate and some of the channels are arranged outside of the base plate, the pair of base plates of the evaporator are arranged with their respective first surfaces towards each other;

a condenser for passing a heat load to surroundings, the condenser including channels extending from a manifold at a first end of the condenser to a manifold at a second end of the condenser;

pipes connecting the evaporator and condenser to each other in order to pass fluid between the evaporator and condenser;

at least one riser pipe connecting the manifold at the second end of the evaporator to the manifold at the second end of the condenser; and

at least one return pipe connecting the manifold at the first end of the condenser to the manifold at the first end of the evaporator;

two riser pipes connecting opposite ends of the manifold at an upper end of the evaporator to the opposite ends of the manifold at an upper end of the condenser; and

two return pipes connecting opposite ends of the manifold and a lower end of the condenser to opposite ends of the manifold at a lower end of the evaporator.