JPH025319Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a refrigeration system that performs stable compressor operation against load fluctuations.

Conventionally, as a speed control means for an outdoor blower that exchanges heat with the outside air by the heat source side evaporator, a method that detects the discharge gas pressure from the compressor (Japanese Patent Application Laid-open No. 49-46243) and a method that detects the outside air temperature have been used. (Jikko 47-
17962), but it is difficult to say that either method alone can accurately control the speed of the outdoor fan.

In other words, although the compressor input is generally approximately proportional to the refrigerant condensing temperature, when the outside air temperature of the air heat source side evaporator is low, the compressor input is relatively small even if the refrigerant condensing temperature (pressure) is high. Although there is no need to lower the speed of the outdoor blower, the former method has the disadvantage that the speed is automatically controlled, which reduces the amount of air drawn from the outside air heat source and shortens the operating range.

Also, when the refrigerant condensing temperature (pressure) is low, the input to the compressor is relatively small even if the outside air temperature is high, and although there is no need to reduce the speed of the outdoor fan, the latter method automatically controls the speed in the same way. This has the drawback of reducing the amount of air drawn from the outside air heat source and shortening the operating range.

On the other hand, as proposed in Japanese Utility Model Application Publication No. 50-114962, the outdoor blower of the heat source side evaporator is switched between strong wind operation and weak wind operation depending on the outside temperature, and when the high pressure exceeds the set value, the In order to prevent the load, attempts have been made to force the blower to operate with a gentle breeze. However, as mentioned above, when the outside temperature is low, even if the high pressure is high, the input to the compressor is relatively small, and to prevent high loads, it is sufficient to simply lower the outdoor blower from strong wind operation to weak wind operation. However, this system had the drawback that the high-pressure switch to prevent high loads was activated and the system was switched to light-air operation, which automatically reduced the amount of air drawn from the outside air heat source and shortened the operating range.

Also, when the high pressure is low, the input to the compressor is relatively small even if the outside temperature is high, and although there is no need to set the outdoor blower to low-air operation, with this method, the high-pressure switch only works to prevent high loads. There was a drawback that the system was switched to low-wind operation based only on the outside air temperature, thereby reducing the amount of air pumped from the outside air heat source and reducing the operating range.

In view of this, the purpose of this proposal is to allow the compressor to operate stably under a constant load even when the load on the heat source side and the load on the user side fluctuate, thereby expanding the operating range. In order to achieve this objective, the present invention connects a compressor, a user-side condenser, a pressure reducing element, and a heat source-side evaporator in a circular manner, and also includes a detector for detecting the temperature or pressure of the refrigerant in the user-side condenser. ,
The evaporator is equipped with a detector that detects the outside air temperature, and a controller that reduces the speed of the blower of the heat source side evaporator when the detected values of both the detectors exceed a set value. .

An embodiment of the present invention will be described below based on the drawings. In the piping system diagram in Fig. 1, 1 is a compressor;
2 is a user side condenser, 3 is a pressure reducing element consisting of an expansion valve or a capillary reach tube, 4 is a heat source side evaporator installed outdoors, and a refrigerant temperature detector 5 is installed at the refrigerant outlet piping of the user side condenser 2. , an outside air temperature detector 6 is provided at the outside air intake side of the heat source side evaporator 4,
A controller 8 is provided which reduces the speed of the blower 7 of the heat source side evaporator 4 when the detected values of both the detectors 5 and 6 exceed their respective set values.

Further, 9 is a main water heat exchanger arranged in a heat exchange relationship with the user side condenser 2, 10 is an auxiliary water heat exchanger that is reheated by a heater 12 of an auxiliary heat source device 11 such as a boiler,
13 is a thermo valve for keeping the temperature of hot water substantially constant; 14 is a hot water storage tank having a hot water outlet 15 for taking out hot water for hot water supply; and a water inlet 16 for introducing city water; and 17 is a circulating water pump.

Next, the operation will be explained with reference to FIG. During hot water tapping operation in which hot water is generated in the main water heat exchanger 9 by drawing a heat source from the outside air by operating the compressor 1 and the blower 7, the amount of hot water used is small and the condensed refrigerant temperature becomes higher than the set value _T3 , and When the outside air temperature becomes higher than the set value _t3 , such as in the summer, the blower 7 is stopped by the AND output signals of both the detectors 5 and 6, and the compressor 1 is allowed to continue operating under a constant load.

Then the condensing refrigerant temperature is higher than the set value T ₂ ,
In addition, when the outside air temperature is higher than the set value _t2 , such as in the middle of spring and autumn, the blower 7 is operated at low wind speed by the AND output signals of both detectors 5 and 6, and the condensed refrigerant temperature is higher than the set value _T1 , and When the outside temperature is higher than the set value _t1 , such as in winter, the blower 7 is operated at medium speed based on the AND output signals of both the detectors 5 and 6. If the temperature is outside the above-mentioned temperature range, the blower 7 is operated with strong wind.

In particular, when the auxiliary heat source device 11 is used together as in the embodiment of the present invention, if the capacity of the auxiliary heat source device 11 is relatively small compared to the amount of heat pumped by the refrigerator, the main water heat exchanger 9 may The water temperature may rise and the condensed refrigerant temperature may rise. At this time,
If the outside air temperature is low, the input to the compressor 1 is not so large, so there is no need to reduce the air volume of the blower 7. Conventionally, the blower 7 was controlled solely by the condensed refrigerant temperature (pressure), regardless of the outside temperature. Defects can be eliminated.

Conversely, when the outside air temperature is high, the input to the compressor 1 may become large even if the condensed refrigerant temperature is low.
In this case as well, with the conventional means of controlling the blower 7 solely based on the temperature (pressure) of the condensed refrigerant, the air volume of the blower 7 would not drop and an overload would be applied to the compressor 1. Stable operation is achieved under a load of

The detector 5 for detecting the condensed refrigerant temperature is most preferably installed at the refrigerant outlet of the user-side condenser 2 as in the above embodiment, but this detector 5 can be replaced with a pressure sensor for detecting the condensed refrigerant pressure. It is also possible. Of course, when used as a pressure sensor, it may be installed at the refrigerant inlet of the user-side condenser 2.

As described above, the present invention separately detects the outside air temperature as the load on the heat source side of the evaporator, and the temperature or pressure of the refrigerant in the condenser section as the load on the user side of the condenser. When either value exceeds the set value, the speed of the fan on the heat source side evaporator is reduced to high, medium, low, and then stopped, so even if both loads fluctuate simultaneously or individually, the It is possible to perform stable operation over a wide range of conditions, and also to secure the maximum amount of heat pumped up from outside air.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a piping system diagram, and FIG. 2 is an operational diagram of the blower. DESCRIPTION OF SYMBOLS 1... Compressor, 2... Utilization side condenser, 3... Pressure reduction element, 4... Heat source side evaporator, 5... Refrigerant temperature (pressure) detector, 6... Outside air temperature detector, 7... Air blower, 8...
controller.

Claims (1)

[Scope of utility model registration request] A detector that connects the compressor, the user-side condenser, the pressure reduction element, and the heat source-side evaporator in a circular manner, and detects the temperature or pressure of the refrigerant in the user-side condenser;
A refrigeration system comprising: a detector that detects outside air temperature; and a controller that reduces the speed of the blower of the heat source side evaporator when the detection values of both detectors exceed a set value.