Abstract: A tube bundle heat exchanger includes tubes channeling a gas flow and a pressure shell enclosing the tubes channeling a coolant flow. First and second nozzles are disposed at a rear end of the pressure shell and third and fourth nozzles are disposed at a front end of the pressure shell. A feed pipe includes a first three-way valve and a drain pipe includes a second three-way valve. A first bypass pipe is connected to the first three-way valve and the third nozzle, a second bypass pipe is connected to the first three-way valve and the first nozzle, a third bypass pipe is connected to the second three-way valve and the second nozzle, and a fourth bypass pipe is connected to the second three-way valve and the fourth nozzle. One of the three-way valves is controllable.

Abstract: A tube bundle heat exchanger includes tubes channeling a gas flow and a pressure shell enclosing the tubes channeling a coolant flow. First and second nozzles are disposed at a rear end of the pressure shell and third and fourth nozzles are disposed at a front end of the pressure shell. A feed pipe includes a first three-way valve and a drain pipe includes a second three-way valve. A first bypass pipe is connected to the first three-way valve and the third nozzle, a second bypass pipe is connected to the first three-way valve and the first nozzle, a third bypass pipe is connected to the second three-way valve and the second nozzle, and a fourth bypass pipe is connected to the second three-way valve and the fourth nozzle. One of the three-way valves is controllable.

Abstract: A tube bundle heat exchanger has at least one channel that carries a heating or cooling medium, whereby the tubes of the tube bundle extend essentially axis-parallel to the channel longitudinal axis through the channel. The heating or cooling medium is directed through alternating rings and discs fastened to the respective jacket walls of the channel, in a zigzag pattern as seen in the axial direction of the channel. The channel has an essentially annular cross section. In at least one channel, the rings and discs accommodate and position all the tubes of one channel, each by means of cylindrical recesses, and the perimeter contour of the rings and discs on the medium flow-through side follow the mid-points of the outermost or innermost tube bundle tubes. The perimeter contour includes a web that surrounds all of the outermost or innermost tubes.