NO122024B - - Google Patents

Description

Procedure for capacity regulation of a cooling system.

The present invention relates to a method for capacity regulation of the compressors for cooling systems for cooling one or more objects. Until now, use has been made of one or another secondary control object, such as evaporation pressure or brine temperature, while the capacity according to the invention is controlled directly by the room temperature" The peculiarity of the invention can be seen from the patent claims below"

The invention shall be explained with reference to the drawing which schematically shows a cooling system.

In the drawing, 1 indicates a compressor which forms part of a boiler plant with the known components condenser, expansion valve and evaporator or brine jackets. The rooms to be heated are denoted by 2, 3 and k and in each of these there is a temperature controller 6 which is connected to a temperature controller 5. This gives impulse to a valve 9 in a line from the compressor 1 to an air controller 8 in the relevant room for opening or closing for the supply of cooling medium or coolants to the chiller. The valve 9 can optionally be placed in the return line to the compressor, i.e. after the air cooler.

The regulation takes place in the following way. The rooms' heating period is started in turn and the duration of these periods is proportional to the actual and the set temperature,

however, at least for a certain time, e.g. two minutes. At a certain specified time after this period has begun or ended, the compressor switches to cooling either only this room or also the next room 3 in a similar way", As soon as the cooling of all rooms has been started in this way, a e.g. electronically by means of a device 7 a mean value of the dress periods included in the cycle. This average value is the basis for adjusting the compressor's capacity to a value that is proportional to this average value. According to the example above, the mean value should be two minutes, giving 100% capacity and one minute, i.e. 50% capacity.

In the above way, the cycle is created continuously

with reduction of the temperature deviations in the rooms in turn and order and dressing periods proportional to these deviations. After each round, a correction of the compressor's capacity is obtained to a value that is proportional to the new mean value.

By regulating the compressor's capacity in this way, the following advantages are achieved. 1. No additional setting of any intermediate process value, such as e.g. brine temperature or evaporation pressure for regulation of the compressor's capacity is required. 2. No correction necessary of the set desired value for capacity regulation as a result of changed operating conditions. 3. Small temperature difference is achieved above. the air skirts, which gives small temperature fluctuations.

k0 The capacity regulation works quietly and stably.

These advantages have been confirmed by practical trials. The dressing takes place in the normal way up until now, i.e. dressing all rooms at the same time.

Claims (1)

Procedure for capacity regulation of compressors (1) for cooling systems for cooling one or more objects (2, 3 > ^) to the desired temperature, characterized in that a temperature regulator (5) regulates the supply of a cooling medium or a coolant to the heat exchanger arranged for each object, and this for the initiation of cooling of one or more objects at a time and so that the cooling period for each object is proportional to the difference between the actual temperature and the set desired temperature, which is described by a device (7), for example electronic, which calculates the mean value of these wear periods after each round of all objects and changes the compressor's capacity to a level that is proportional to this mean value