EP2187154A1 - Device for splitting a heat distributor circulating in a closed cooling circuit - Google Patents

Abstract

An air conditioning assembly distributes a cold water within a closed circuit. The water is chilled at a cooling station and is then piped to the appropriate user point at the desired temperature. The assembly has primary and secondary feed and return pipe circuits. Each feed circuit (10, 11, 12, 13) has a first container (30) in and a second container (31) is located in the return circuit (14, 15, 16, 17). The return circuit container (31) is located at a point higher than the feed circuit container (30). Both containers are linked by a pipe (32).

Description

The invention relates to a device for distributing a circulating in a closed circuit heat carrier, which is cooled in a cold source and provided according to the requirements of each consumer in terms of the desired temperature, with at least one primary and at least one secondary flow and return circuit.

The invention relates to refrigeration and air conditioning systems for the air conditioning of buildings and also to cooling systems in the commercial sector.

Although different media come into question as heat transfer, the present invention advantageously relates to the so-called water-bound transport of cold air. Such cooling systems provide a high level of comfort at the same time low energy consumption, with a high flexibility is given.

In particular, the invention relates to cold water systems or cold water hydraulic systems.

Before presenting the problem underlying the invention, fundamental differences between a cold water distribution system (cooling) and a hot water distribution system (heating) will be discussed. In a hot water distribution system, the temperature difference between the surface of a radiator and the air may range between 5 to 70 K, while in a cooling system between the active surface and the surrounding air only 5 to 10 K are possible. The so-called. Temperature spread between the supply and the return is in a heating system between 5 to 20 K, while in a cooling system only 2 to 6 K come into question. In a heating system it is possible to vary the flow temperature between plus / minus 5 to plus / minus 15 K for power control. In a cooling system, lowering the flow temperature is not possible because of the risk of condensation and freezing. In addition, the usual chillers should be operated with their specified power in order not to suffer significant losses in efficiency. This applies to all refrigeration variants, ie for compression and absorption refrigeration machines, and also for so-called evaporative cooling.

It is advantageous to construct the so-called. Cold source of chillers of different rated power, thereby adapting to changing and fluctuating requirements of consumers with regard to the reached there cold water temperature. But this complicates the hydraulic conditions in the circuit.

The present invention is a device of the type mentioned in a compact design to be created, ie a small footprint in the engine room, a lower floor load and in particular a lower transport weight of the system parts are possible.

This is achieved in a device of the type mentioned, which is characterized in that in each case a first container in the or in the feed circuits and a second container is arranged in the or in the return circuits, the return circuit container above the flow circuit container is arranged and that both containers are connected to each other via at least one line.

In the apparatus according to the invention is located both in the flow and in the return one container, and these containers are spatially arranged one above the other and connected to each other in a line. This makes it possible, only one part - depending on the requirements of the consumer - to circulate the coming of the cold spring cold water flow in the flow, with another part passes through the line connection between the containers in the return circuit.

In a preferred embodiment of the invention, the line connecting the container is designed for a throughput of 90% of the largest heat transfer stream of the cold source, with flow rates of 0.8 to 1.0 m / s are sought. This can be achieved according to the invention that turbulent flows arise, yet a full hydraulic Decoupling of the individual circuits with low pressure loss remains ensured.

In constructing the cold source from a plurality of refrigerators, the flow rate of the connecting pipe is set at 90% of the largest heat carrier flow of the largest power chiller, and also the advantages in terms of turbulent flow and hydraulic decoupling are ensured.

The cold switch can be operated within the container with turbulent flows. As a result, much smaller containers are required, resulting in a much smaller site and a much smaller operating weight.

This type of construction does not result in any mixing between the cold water (HC supply and return with their very small temperature differences of 4-6 ° K.) Smallest mixing of the HC supply and return means that the efficiency of the refrigeration machines (COP Value, EER value) decreases and thus more electrical energy is consumed at the same cooling capacity for cooling, eg the end units of the heat exchangers of the air handling units, circulating air coolers etc. are designed for a KW temperature of 6 ° C VL and 12 ° C RL to cool rooms, machines and other things.

At a low mixing of z. For example, only 1 ° K, i. from 6 ° K to 7 ° K VL temperature, the chiller must be set to a VL temperature of 5 ° K to reach the required 6 ° K at the end user. In this mode of operation, the efficiency of the chiller decreases by at least 5 - 10%.

The chiller can primarily be connected to unlimited refrigerators (refrigerators, chillers) with the same or different outputs, cold water quantities and pump pressures.

Secondarily, consumers with the same or different capacities, cold water quantities and pump pressures can also be connected indefinitely.

In addition, each individual consumer can vary in power, water quantity and pump pressure from 0 to 100%.

The "hydraulic zero point" of the entire system always remains the cold switch. The normally required time-consuming and complicated hydraulic adjustment of individual system parts is eliminated.

The cooling switch is in addition to the function as a hydraulic switch also expandable to the buffer tank by the lower and / or upper container serves as a buffer memory.

This is necessary if cold water systems with low liquid contents are to be operated in order to avoid the so-called "clocking" (frequent switching on and off). to avoid the chiller. If a chiller cycles frequently, it becomes susceptible to failure and wear increases, which results in higher maintenance and repair costs.

The invention will be explained below with reference to the drawing, for example.
The Fig. 1 shows a device according to the invention with two refrigerators and two consumers.
The Fig. 2 to 6 point to the device Fig. 1 Examples of possible operating cases with different load and different power of the cold source.

In the Fig. 1 two chillers or chillers KWS 1 and KWS 2 are shown schematically and these two chillers form the so-called. Cold source.

From the chiller 2, a primary flow 10 to a container 30 and from this via a pump via a secondary flow line 12 to a consumer 20 at the consumer 20 starts the secondary return 17 and this leads to another container 31. The two outputs of Container 31 are the first primary return 14 and the second primary return 15. The line 14 is connected to the refrigerator 2 and the line 15 to the refrigerator 1. In a corresponding manner, a primary flow line 11 is connected to the first refrigerator 1 and the container 30. From the container 30 leads via a further pump, a secondary flow 13 to the consumer 21 and from there via the secondary return 16 to the container 31st

Consumers 20 and 21 have been marked 10 to 100% to express that they may have a demand for cold water between 10% and 100% of a nominal value.

From the foregoing description it is apparent that even more chillers could be used in a corresponding manner, the same applies to other consumers.

According to the invention, the containers 30 and 31 are arranged one above the other, wherein from the lower container 30 in the embodiment shown, a line 32 to the container 31 are guided. In this line, a valve is shown, but this valve is irrelevant in connection with the function of the present invention.

The line 32 is a hydraulic connection between the containers 30 and 31, they are dimensioned so that there speeds of 0.8 to 1.0 m / s of the heat carrier are possible. Incidentally, it is dimensioned so that it can absorb 90% of the media volume of the largest of the chillers.

In the device according to the invention, a plurality of chillers can be used, since the cold water flow generated by the chillers is conveyed from the primary circuit without any mixing in the secondary circuit. The stacked arrangement of the container serves as a "plant O-point" and decouples the fixed volume flows of the cold source, so the primary circuit of the variable network circuits.

The containers 30 and 31 correspond to the buffer tanks and the hydraulic switches in heat engineering systems and can be designed accordingly and sized in size. Advantageous lying elongated container, the upper rests directly on the lower.

Claims (3)

Device for distributing a circulating in a closed circuit heat carrier, which is cooled in a cold source and provided according to the requirements of the respective consumer with respect to the desired temperature, with at least one primary and at least one secondary flow and return circuit, characterized in that each one first container (30) is arranged in the one or more supply circuits (10, 11, 12, 13) and in each case a second container (31) in the or in the return circuits (14, 15, 16, 17), the return circuit container (31) above the flow circuit container (30) is arranged and both containers via at least one line (32) are interconnected. Apparatus according to claim 1, characterized in that the line (32) for a throughput of about 90% of the largest heat carrier stream of the cold source (1,2) is designed with flow rates of 0.8 to 1.0 m / s. Apparatus according to claim 1, characterized in that in the construction of the cold source (1, 2) from a plurality of chillers or chillers, the line (32) for a throughput of about 90% of the largest heat transfer flow of that chiller with the highest performance with flow rates from 0.8 to 1.0 m / s.

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