CN108895735A - A kind of freezer unit automation frost control method - Google Patents

Abstract

The invention discloses a kind of freezer unit automation frost control methods, including：Step 1. detects freezer evaporator disengaging air temperature and unit low pressure in unit refrigerating operaton；Step 2. judges whether that the continuous t1 time detects that the difference of disengaging air temperature is more than or equal to zero, and is less than or equal to a difference, 0≤（T_{Air inlet}‑T_{Outlet air}）≤ △ T, if not, continuing to monitor；If so, then going to step 3；Step 3. judges whether that the continuous t2 time detects P_{It is low}≤ P then enters defrost program if not, continuing to monitor in this way.The present invention comprehensively considers according to the particularity of freezer unit, many factors such as combination pressure, the temperature difference, temperature, is precisely controlled the interior machine automatic defrosting of freezer, works well.

Description

A kind of freezer unit automation frost control method

Technical field

The present invention relates to refrigeration technology field more particularly to a kind of freezer unit automation frost control methods.

Background technique

The defrost pattern that most freezer units use currently on the market is all interval defrost, though this defrost pattern It is so simple, but there is a problem of what interval time was difficult to control, such as：The interval defrost time of one freezer setting is 6 hours, In the case where the amount of stocking up or bigger shipment amount（Freezer door opening times are more）, full frost may have been tied by machine in 4 hours, still According to interval defrost pattern, unit also need to run 2 hours could defrost, be likely to during this evaporator occur to be blocked up by frost It is full, it can not exchange heat, the disorderly closedowns such as low-voltage variation occur.On the contrary, under the premise of small into shipment amount, it may be in 6 hours The also non-frosting of machine, but according to interval defrost pattern, unit can automatically begin to defrost, there have been no white but startingizations at this time The problem of frost operation.

Therefore, how to efficiently solve traditional freezer defrost problem is industry technical problem urgently to be resolved.

Summary of the invention

The present invention is unable to satisfy the technical issues of freezer needs to solve interval defrost existing in the prior art, proposes A kind of freezer unit automation frost control method.

Freezer unit automation frost control method proposed by the present invention includes：

Step 1. detects freezer evaporator disengaging air temperature and unit low pressure in unit refrigerating operaton；

Step 2. judges whether that the continuous t1 time detects that the difference of disengaging air temperature is more than or equal to zero, and is less than or equal to a difference Value, 0≤（T_{Air inlet}- T_{Outlet air}）≤ △ T, if not, continuing to monitor；If so, then going to step 3；

Step 3. judges whether that the continuous t2 time detects P_{It is low}≤ P then enters defrost program if not, continuing to monitor in this way.

Preferably, the time t1 is 3 minutes, and the t2 time is 3 seconds.

The beneficial effects of the invention are as follows：By combining suction pressure of compressor, the conditions such as evaporator air inlet/outlet temperature difference, pressure And temperature various dimensions comprehensively consider, precisely controlling system automatic defrosting, realization has white timelyization, frostless, the automatic defrosting that do not change Control model.

Detailed description of the invention

Fig. 1 is the system diagram of freezer unit；

Fig. 2 is the flow diagram of control method of the present invention.

Specific embodiment

The present invention is described further with reference to the accompanying drawings and examples：

Fig. 1 is the system diagram of freezer unit.Freezer unit includes compressor 1, gs-oil separator 2, condenser 3, expansion valve 4, steams Send out device 5, gas-liquid separator 6 and controller 7.Air inlet/outlet temperature sensor is set on an evaporator, for detecting air inlet and the outlet temperature Degree.Pressure sensor is set in the suction pipe of compressor, for detecting the low pressure of unit.

Fig. 2 is the flow diagram of control method of the present invention.Freezer proposed by the present invention unit automation frost controlling party Method includes：

Step 1. detects freezer evaporator disengaging air temperature and suction pressure of compressor in unit refrigerating operaton；

Step 2. judges whether that the continuous t1 time detects that the difference of disengaging air temperature is more than or equal to zero, is less than or equal to a difference Value, 0≤（T_{Air inlet}- T_{Outlet air}）≤ △ T, if not, continuing to monitor；If so, then going to step 3；

Step 3. judges whether that the continuous t2 time detects P_{It is low}≤ P then enters defrost program if not, continuing to monitor in this way.

The above T_{Air inlet}、T_{Outlet air}For freezer evaporator air inlet, the real-time temperature values of leaving air temp sensor detection, the tool of air inlet/outlet Body position system diagram shown in Figure 1.The temperature difference △ T of above-mentioned disengaging air temperature is setting value.P_{It is low}For the suction of compressor Atmospheric pressure, the real-time pressure value detected by low pressure sensor.P is the setting value higher than low-voltage variation.

Defrosting control method proposed by the present invention must simultaneously meet following two condition, and unit just enters automatic defrosting：

（1）The continuous t1 time under compressor unlocking condition, the embodiment are 3min, detect 0≤T_{Air inlet}- T_Air-supply≤ temperature difference △ T；

（2）Continuous t2 time, the embodiment are 3s, detect P_{It is low}≤P。

Automatic defrosting method proposed by the present invention combines comprehensively considering for pressure, the temperature difference and temperature many factors, can essence Automatic defrosting when quasi- control freezer is full white with interior machine knot.Wherein：

Condition（1）：It is less than or equal to a temperature difference with the evaporator air inlet/outlet temperature difference and locks frosting, is specific to freezer unit Setting.Freezer evaporator generally selects finned tube evaporator.Spacing of fin is bigger than normal（Spacing of fin is generally 4mm or 7mm）, Carry the white ability unit small much larger than household machine or other fins（Spacing of fin is generally 1.6mm）.Because of above-mentioned particularity freezer With interior machine frosting, there are two change procedures, and at frosting initial stage, interior machine windage increase, air quantity reduction, the air inlet/outlet temperature difference becomes larger, to frost knot The exchange capability of heat of Man Hou, whole system are greatly decreased, although air quantity becomes smaller, interior machine no longer exchanges heat substantially at this time, thus into The outlet air temperature difference can also become smaller.So particularly suitable to lock frosting with a temperature difference is less than or equal to.Household machine or other fins Small unit is typically all to lock frosting with a temperature difference is more than or equal to, because spacing is small, a frosting is just changed Frost, otherwise fin frost is stifled, defrost not in time can low-voltage variation shut down, general all only one change procedure.

Condition（2）It is in condition（1）Theoretical basis on the supplement that carries out.Condition（2）The restriction of pressure has further been done, When the full frost of unit knot, the pressure of inspiration(Pi) of unit is bound to very low, and the restriction for doing a pressure at this time is to exclude other and knot The air inlet/outlet temperature difference is less than or equal to other special circumstances of a certain value when full frost, for example, in machine type selecting it is excessive, the air inlet/outlet temperature difference is normal It is less than normal when operation.It is all outer machine defrost when general household machine heating, original condenser is used as evaporator, is generally not present The too small problem of interior machine does not have to then consider pressure qualifications.

The present invention comprehensively considers according to the particularity of freezer unit, many factors such as combination pressure, the temperature difference, temperature, Propose a kind of method of automatic defrosting when being precisely controlled freezer full with interior machine knot frost, through experimental examination, defrosting effect of the present invention Well.

Above embodiments are for illustrating this creating conception of the invention and specific embodiment, it is noted that for For those skilled in the art, without departing from the inventive concept of the premise, various modifications and improvements can be made, These are all within the scope of protection of the present invention.

Claims (2)

1. a kind of freezer unit automation frost control method, which is characterized in that including：

Step 1. detects freezer evaporator disengaging air temperature and unit low pressure in unit refrigerating operaton；

Step 2. judges whether that the continuous t1 time detects that the difference of disengaging air temperature is more than or equal to zero, and is less than or equal to a difference Value, 0≤（T_{Air inlet}- T_{Outlet air}）≤ △ T, if not, continuing to monitor；If so, then going to step 3；

Step 3. judges whether that the continuous t2 time detects P_{It is low}≤ P then enters defrost program if not, continuing to monitor in this way.

2. control method as described in claim 1, which is characterized in that the time t1 is 3 minutes, and the t2 time is 3 seconds Clock.