Combined Fluid-Air Evaporator And Novel Switching Concept For A Heat Pump In A Ventilating Apparatus

Abstract

A combined fluid-air evaporator having at least two separate duct systems is described, through which separate material flows may be conducted, at least one of the two duct systems having a free surface which may be brought into thermal contact with an air flow, and the at least two duct systems being at least partially in thermal contact with one another. Furthermore, a ventilation arrangement for a building is described using the combined fluid-air evaporator, in which a used air flow directed out of the building, which is in thermal contact with an outside air flow via an air-air heat exchanger, comes into thermal contact with the combined fluid-air evaporator, through which a refrigerant and an exothermic fluid pass, the refrigerant circulating in the loop of a heat pump, whose condenser is connected downstream in the flow direction from the air-air heat exchanger in the heated outside air flow, and the exothermic fluid circulates in the loop of a heat accumulator system.

Description

TECHNICAL AREA [0001] The present invention relates to a combined fluid-air evaporator, which is preferably usable as a refrigerant evaporator for a ventilation arrangement provided for buildings. For this purpose, the term “fluid” comprises, in the expanded definition, all phase states of materials with the exception of the solid phase, and thus particularly the liquid phase and also the gas phase. A preferred integration of the combined fluid-air evaporator with a heat pump is also described. BACKGROUND INFORMATION [0002] In newly constructed apartment houses, strengthened ventilating apparatuses having heat reclamation are increasingly installed, which result in higher living comfort, since the required air exchange is ensured automatically and the temperature level of the intake air is significantly raised by the heat reclamation. Through the targeted exploitation of the used air heat to preheat the intake air using an air-air heat exchanger, the heating operation for a building...

AI Technical Summary

Benefits of technology

[0008] The present invention is based on the object of specifying an achievement of the object specified above, so that changing over between heating and cooling operation of a heat pump integrated in a building ventilation arrangement is possible using means which are as technically simple as possible to implement. The icing occurring in the known heat pumps is to be largely avoided, and the operational reliability and also the service life of the components participating in the loop of heat pumps are particularly to be improved.

[0014] An alternative embodiment of the combined fluid-air evaporator according to the present invention provides a single pipeline, which has an internal partition wall that partitions the pipeline along its entire extension into two pipeline halves. In this case as well, two material flows passing through the particular pipeline halves come into thermal contact with one another through the internal partition wall and, in addition, heat transfer between the individual fluid flows and an air flow flowing around the pipeline is ensured.

[0017] With the aid of the refrigerant evaporator implemented according to the present invention, which may be integrated particularly advantageously as an evaporator unit in a heat pump unit, the heat pump obtains a decisive advantage in regard to reduction of the icing danger at low operating temperatures. In addition, the efficiency of the heat pump increases, since the evaporation temperature is elevated by the additional heat contribution in the evaporator, through which less energy is to be invested in the operation of the heat pump.

[0018] Through integration of a heat pump as described above in a ventilation arrangement for a building, multiple extremely interesting and technically simple building aeration and building ventilation constellations having different heating and cooling variations may be provided.

[0020] The main advantage of the ventilation arrangement described above is that the evaporator of the heat pump in the form of the combined fluid-air evaporator implemented according to the present invention has the refrigerant of the heat pump and also at least one further fluid flowing through it, whose heat content is transferred to the refrigerant of the heat pump through direct thermal coupling. In this way, it is possible to significantly reduce the icing danger of the evaporator, particularly at cold ambient temperatures, and in addition the evaporation temperature may be raised, through which the energy input required for heat pump operation may be reduced and, above all, the cooling performance of the heat pump may thus be increased.

[0022] The suggested integration of the heat pump implemented according to the present invention also allows especially advantageous heating and / or cooling of old buildings, especially since different heat sources may be selected by the combined fluid-air evaporator depending on the outside temperature. For example, the outside air may be used for heating in the transition time (spring / autumn) and at low outside air temperatures, as occur in winter, a ground collector may be put online. The current hottest heat source is used for the industrial water heating. Combinations of both heat sources are also conceivable. In this way, a constant higher evaporation temperature and, connected therewith, a higher heating performance, may be achieved.

Problems solved by technology

Particularly in the case of lower temperatures, at which the cooled building used air flows through the evaporator of the heat pump, icing frequently occurs within the evaporator, through which the function of the heat pump is disadvantageously influenced until breakdown, so that suitable measures are to be taken to counteract corresponding occurrences of icing.

However, for this purpose four-way valves or three-way valves having possible leaks are required within the complicated loop systems in which heat pumps are integrated.

The use of expensive solenoid valves is also known, through which the cooling loop becomes more complicated, more expensive, and more susceptible to breakdown.

In addition, upon changeover between heating and cooling operation of the heat pump, the cooling loop briefly becomes unstable, which results not only in reduction of the performance number of the heat pump, but rather in addition causes reduction of the service life of the compressor.

However, above all in typical air-water heat pumps, the icing of the evaporator represents a large problem.

Thawing must be performed very often below the specified outside temperatures, however, through which the performance number of the heat pump worsens.

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