CN1979063B - A kind of antifreeze method of air conditioner - Google Patents

Abstract

The invention relates to a method to improve the antifreeze ability for air condition. It includes the following steps: minimum water flow would be controlled by a flow controller at water outlet, setting an antifreeze value, when water temperature lowering than the value, the set would stop running and output alarm. If the water temperature at water intake is lower than a set temperature value, and the temperature difference at outlet and intake exceeding a set value, and lasting for a time span, it would be judged as not enough water flow. The machine would be stopped and output alarm.

Description

A kind of antifreeze method of air conditioner

【Technical field】

The invention belongs to the field of air conditioners, and in particular designs a method for improving the antifreeze ability of the air conditioner by changing the design logic of the air conditioner.

【Background technique】

With the development of technology and the progress of society, air conditioners, as a household appliance, have been widely used in homes and offices. Central air-conditioning generally uses water as the medium for secondary heat exchange. Appropriate water flow is a necessary guarantee for the reliable operation of the central air-conditioning host. Improper water flow may cause freezing of the evaporator of the chiller, high condensation pressure, and "biting" of the compressor. ” and other failures, so the appropriate water flow detection method and detection components are to ensure that the unit only works when the system water flow is greater than the allowable minimum water flow, so as to avoid the failure of the air conditioner host. When there is no water flow or less water flow, for the evaporator, the evaporator load decreases and the evaporation temperature decreases. If the compressor continues to run, the evaporator will freeze. If the evaporator cannot be protected against freezing in time, the evaporator will most likely burst , leading to the collusion between the water side and the refrigerant side of the refrigeration system, and the entire refrigeration system is scrapped. In addition, if the water flow of the water system is too low for a long time, the return air pressure will be too low for a long time, and the lubricating oil discharged from the compressor cannot return to the compressor smoothly, which may cause the compressor to "bite the cylinder". In the Chinese patent 99250859.2 named as an air conditioner antifreeze device, a device consisting of a heating tank and a fin heat exchanger is disclosed. The heating tank and the fin heat exchanger are connected in series to form a circulation loop through pipelines and pumps. , Antifreeze is injected into the circulation loop, and a heating device is installed in the heating tank, which can heat the antifreeze and circulate it through the pump. This kind of antifreeze device for air conditioners is only used in the air conditioners that are heated through pipelines in northern my country, and the north is usually called heating. It does not really use the technology used in heating and cooling air conditioners that use electricity to cool and heat at the same time. As shown in Figure 2, in the existing industry technology, it is more common to use a flow controller at the water outlet 8 to control the minimum water flow, and the water inlet is 9; set an antifreeze temperature value, when the water outlet 8 temperature sensor 7 When it is tested that the water temperature is lower than this value, the controller of the unit stops the operation of the unit and outputs antifreeze. The air conditioner adopting the above-mentioned method can only possess the antifreeze function under normal circumstances. In some relatively cold regions or when the temperature drops suddenly, it is difficult to cope with the air conditioner adopting the above-mentioned technology.

【Content of invention】

In order to solve the above problems, the purpose of the present invention is to provide an air conditioner that does not require too many improvements, but only adds some control methods in its antifreeze control logic to realize the improvement of the antifreeze ability of the air conditioner.

In order to solve the above-mentioned problems, the present invention adopts the following technical solutions: an air-conditioning antifreeze method, including using a flow controller at the water outlet to control the minimum water flow; When this value is reached, the controller of the unit stops the operation of the unit and outputs an antifreeze alarm, and the following content is added to the control logic of the air conditioner:

a. When the inlet water temperature is lower than a set temperature value, and the temperature difference between the inlet and outlet water exceeds a set temperature difference, and lasts for a certain period of time, it will be judged that the water flow is insufficient, stop and output an alarm for insufficient water flow;

b. After the compressor has been running for a certain period of time, when the temperature drop of the outlet water is lower than a set antifreeze limit value, it will be judged that the water pump is not running, stop and output an antifreeze alarm, but this alarm is only detected during the initial stage of compressor operation;

c. The refrigeration and antifreeze temperature setting is valid for both the inlet and outlet water, that is, the compressor must be stopped when the inlet or outlet water temperature reaches the antifreeze temperature;

d. When the compressor runs for a certain period of time and the inlet water temperature is lower than the outlet water temperature, it will stop and output an antifreeze alarm;

e. The above alarms can only be cleared after pressing the shutdown button.

For the above technical content, the more specific limitation is that the added setting content in the control logic is:

a. When the inlet water temperature is lower than 20°C, and the temperature difference between the inlet and outlet water exceeds 9°C for 3 seconds, it will be judged that the water flow is insufficient, stop and output an alarm for insufficient water flow;

b. After the compressor runs for 20 seconds, if the outlet water temperature drops below 1°C, it will be judged that the water pump is not running, stop and output an antifreeze alarm. This alarm is only detected within 20 seconds of the compressor running;

c. The refrigeration antifreeze temperature setting is valid for both inflow and outflow water, that is, the compressor must be stopped when the inflow or outflow water temperature reaches the antifreeze temperature. If the water comes out 5 times in 1 hour, it will alarm. If it is water ingress, it will call the police immediately as long as it occurs once;

d. If the inlet water temperature is lower than the outlet water temperature after the compressor runs for 20 seconds, it will stop and output an antifreeze alarm;

e. The above alarms can only be cleared after pressing the shutdown button.

Due to the adoption of the above-mentioned technical solution, the present invention has obtained the following positive technical effects and advantages: by adopting when the inlet water temperature is lower than a set temperature value, the temperature difference between the inlet and outlet water exceeds a set temperature difference, and After a certain period of time, it is judged that the water flow is insufficient, shut down and output the control logic of insufficient water flow alarm, which can provide a suitable water flow as a guarantee for the normal operation of the air conditioning unit. Too small water flow will cause the chiller evaporator to freeze and condense If the pressure is too high and the compressor bites the cylinder, accurate measurement of the antifreeze temperature can prevent the above failures of the air conditioner; after the compressor has been running for a certain period of time, when the temperature drop of the outlet water is lower than a set antifreeze limit, it is judged that the water pump is not running. Shut down and output antifreeze alarm, but this alarm is only detected in the initial stage of compressor operation, the function of this function is to detect the failure of the water pump. When the water pump breaks down, it cannot reach the water temperature value lowered per unit time in the normal working state. At this time, the output antifreeze alarm can ensure the normal use of the water pump and timely maintenance; the refrigeration antifreeze temperature setting is valid for both incoming and outgoing water. When the water or outlet water temperature reaches the antifreeze temperature, the compressor must be stopped, which can ensure that when the inlet water temperature is lower than the outlet water temperature or the outlet water temperature is too low, the alarm can prevent the cooling water temperature in the system from being too low or even freezing, which will affect the normal operation of the system. In a word, by adopting the above-mentioned control logic, the present invention greatly improves the anti-freezing performance of the existing air-conditioning equipment without changing the structure, and ensures that the entire air-conditioning unit can run stably for a long time.

【Description of drawings】

Fig. 1 is a schematic diagram of the principle of the present invention;

Fig. 2 is a schematic diagram of the prior art of the present invention.

【Detailed ways】

The present invention is further described below in conjunction with accompanying drawing:

As shown in Figure 1, it is a schematic diagram of a central air-conditioning refrigeration system. Among them, 1 is a compressor, 2 is a condenser, 3 is a dry filter, 4 is a throttling device, 5 is a plate heat exchanger, and 6 is a unit controller.

The operation process of the air-conditioning unit is as follows: after the compressor 1 compresses the refrigerant, it is discharged from the compressor 1, so that the refrigerant flows into the condenser 2, and then flows into the dry filter 3 through the pipeline, and the dry filter 3 After drying and filtering, it enters the throttle valve 4, passes through the throttle valve 4, and then enters the plate heat exchanger 5 for heat exchange with water, and then flows back to the compressor 1 for compression, and returns to the next In the refrigeration cycle, there are two water pipes in the plate heat exchanger 5, which are the water inlet pipe and the water outlet pipe respectively, and the water temperature sensors are respectively installed at the water inlet and the water outlet, and the water temperature sensor inputs the signal to the unit control through the wire 6, and set the following control logic in the unit controller 6 to improve the anti-freezing ability of the whole unit.

The control method in the present invention is to set its control logic to the following content. When the inlet water temperature is lower than 20°C, the temperature difference between the inlet and outlet water exceeds 9°C for 3 seconds, it is judged that the water flow is insufficient, the machine is shut down and the output water flow is insufficient to alarm;

b. After the compressor runs for 20 seconds, if the outlet water temperature drops below 1°C, it will be judged that the water pump is not running, stop and output an antifreeze alarm. This alarm is only detected within 20 seconds of the compressor running;

c. The refrigeration antifreeze temperature setting is valid for both inflow and outflow water, that is, the compressor must be stopped when the inflow or outflow water temperature reaches the antifreeze temperature. If the water comes out 5 times in 1 hour, it will alarm. If it is water ingress, it will call the police immediately as long as it occurs once;

d. If the inlet water temperature is lower than the outlet water temperature after the compressor runs for 20 seconds, it will stop and output an antifreeze alarm;

e. The above alarms can only be cleared after pressing the shutdown button.

Through such settings, the antifreeze process of the air conditioner is: when the unit controller 6 detects that the current operating condition of the unit reaches the antifreeze condition, it will input a stop signal to the compressor 1 to stop the compressor 1, and the plate heat exchanger The pressure of the refrigerant in the plate heat exchanger 5 rises rapidly, and the refrigerant in the plate heat exchanger 5 no longer evaporates and exchanges heat. Since the water pump does not stop running at this time, the pressure in the plate heat exchanger 5 is stable, and there will be no more heat exchange caused by the refrigerant in the plate heat exchanger 5. Evaporate and continue to reduce, thereby effectively preventing the plate heat exchanger 5 from being damaged due to low water temperature.

In the present invention, the data listed in the above-mentioned embodiments are not limited to the above-mentioned data in actual use, but their specific values are set according to the operating conditions and specific circumstances of the air-conditioning unit.

Claims (2)

1. An antifreeze method for an air conditioner, including using a flow controller at the water outlet to control the minimum water flow; setting an antifreeze temperature value, and when the outlet water temperature sensor detects that the water temperature is lower than this value, the unit controller stops the unit. Running and outputting an antifreeze alarm, characterized in that the following content is added to the control logic of the air conditioner: a. When the inlet water temperature is lower than a set temperature value, and the temperature difference between the inlet and outlet water exceeds a set temperature difference, and lasts for a certain period of time, it will be judged that the water flow is insufficient, stop and output an alarm for insufficient water flow; b. After the compressor has been running for a certain period of time, when the temperature drop of the outlet water is lower than a set antifreeze limit value, it will be judged that the water pump is not running, stop and output an antifreeze alarm, but this alarm is only detected during the initial stage of compressor operation; c. The refrigeration and antifreeze temperature setting is valid for both the inlet and outlet water, that is, the compressor must be stopped when the inlet or outlet water temperature reaches the antifreeze temperature; d. When the compressor runs for a certain period of time and the inlet water temperature is lower than the outlet water temperature, it will stop and output an antifreeze alarm; e. The above alarms can only be cleared after pressing the shutdown button. 2. The air-conditioning antifreeze method according to claim 1, characterized in that: the added setting content in the control logic is: a. When the inlet water temperature is lower than 20°C, and the temperature difference between the inlet and outlet water exceeds 9°C for 3 seconds, it will be judged that the water flow is insufficient, stop and output an alarm for insufficient water flow; b. After the compressor runs for 20 seconds, if the outlet water temperature drops below 1°C, it will be judged that the water pump is not running, stop and output an antifreeze alarm. This alarm is only detected within 20 seconds of the compressor running; c. The refrigeration antifreeze temperature setting is valid for both inflow and outflow water, that is, the compressor must be stopped when the inflow or outflow water temperature reaches the antifreeze temperature. If the water comes out 5 times in 1 hour, it will alarm. If it is water ingress, it will call the police immediately as long as it occurs once; d. If the inlet water temperature is lower than the outlet water temperature after the compressor runs for 20 seconds, it will stop and output an antifreeze alarm; e. The above alarms can only be cleared after pressing the shutdown button.

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