1. The utility model provides a low temperature type constant temperature and humidity freezer unit control system which characterized in that includes:

the air circulation system (1), the air circulation system (1) includes setting up in the indoor air conduit (14) of freezer, the air intake and air outlet of air conduit (14) all communicate the interior space of freezer, the air conduit (14) divide into table cold section (11), heating section (12) and fan section (13), table cold section (11) are used for the air cooling, heating section (12) are located the air-out side of table cold section (11) and are used for the air heating accuse temperature, be provided with the fan that is used for air circulation in fan section (13); the refrigerator comprises a refrigeration system (2), the refrigeration system (2) comprises a surface cooler (21), a refrigerant pipeline (22) and an outdoor unit (23), the surface cooler (21) is arranged in a surface cooling section (11) and used for cooling air, the outdoor unit (23) is arranged outside the refrigerator and used for dissipating heat, the refrigerant pipeline (22) is connected between the outdoor unit (23) and the surface cooler (21) and used for exchanging heat between the outdoor unit and the surface cooler (21), and the glycol heating system (3) comprises a heating heat exchange pipe (39), a heating medium box (31), a heating input pipeline (34) and a heating return pipeline (38); the heating input pipeline (34) and the heating return pipeline (38) are connected between the heating heat exchange pipe (39) and the heating medium box (31); a waste heat exchanger (35), an air energy heat pump (36) and a heating proportional-integral valve (37) are arranged on the heating input pipeline (34) in sequence; the heating heat exchange tube (39) is arranged in the heating section (12) and used for heating air; the waste heat exchanger (35) is arranged in the outdoor unit (23) and used for waste heat recovery, and the air energy heat pump (36) is used for heating the input pipeline (34); the defrosting system (4) comprises a defrosting sprayer (42), a defrosting medium box (43), a defrosting water inlet pipeline and a defrosting water return pipeline (46); the defrosting water inlet pipeline and the defrosting water return pipeline (46) are connected between the defrosting heat exchange pipe and the defrosting medium box (43); a defrosting heat exchanger (45) and a defrosting proportional-integral valve (41) are arranged on the defrosting water inlet pipeline in sequence; the defrosting heat exchange pipe is connected with the heating input pipeline (34) and is used for heating a medium in the defrosting water inlet pipeline; the defrosting sprayer (42) is arranged in the surface cooling section (11) and is used for spraying and defrosting the surface of the surface cooler (21); the temperature and humidity sensing system comprises an indoor temperature and humidity probe, a surface cooling section temperature probe, a heating water temperature sensor and a defrosting water temperature sensor; the surface cooling section temperature probe is arranged on the surface cooler (21); the heating section temperature probe is arranged on the air outlet side of the heating heat exchanger (39); the heating water temperature sensor is arranged in the heating medium box (31); the defrosting water temperature sensor is arranged on the defrosting water inlet pipeline; and the PLC control system is respectively and electrically connected with the temperature and humidity sensing system and controls the air circulation system (1), the refrigerating system (2), the glycol heating system (3) and the defrosting system (4) in a feedback manner.

2. The control system of the low-temperature constant-humidity refrigerator unit according to claim 1, wherein a waste heat control valve (33) and a heating circulating pump (32) are further arranged on the heating input pipeline (34), the waste heat control valve (33) is connected to the water inlet side of the waste heat exchanger (35), the heating circulating pump (32) is connected to the water outlet side of the heating medium tank (31), and the PLC control system is connected with and controls the waste heat control valve (33) and the heating circulating pump (32).

3. The control system of the low-temperature type constant-temperature and constant-humidity refrigerator unit according to claim 2, wherein the defrosting heat exchanger (45) comprises a heat absorption channel and a heat release channel, two ends of the heat release channel are respectively connected to the heating input pipeline (34) and the heating return pipeline (38), and two ends of the heat absorption channel are respectively connected to the defrosting return pipeline (46) and the defrosting water inlet pipeline.

4. The control system of the low-temperature type constant-temperature and constant-humidity refrigerator unit according to claim 3, wherein the water inlet side of the heat release channel is connected to the heating input pipeline (34) through a defrosting medium temperature control valve (47); the PLC control system is connected with and controls the opening degree of the defrosting medium temperature control valve (47).

5. The control system of the low-temperature type constant-temperature and constant-humidity refrigerator unit according to claim 4, wherein a defrosting circulating pump (44) is arranged at an outlet of the defrosting medium tank (43), and the PLC control system is connected with and controls the start and stop of the defrosting circulating pump (44).

6. The control system of the low-temperature constant-humidity freezer unit according to claim 1, wherein the PLC control system is electrically connected with the indoor temperature and humidity probe, the surface cooling section temperature probe, the heating water temperature sensor, the defrosting water temperature sensor, the heater leakage prevention protection switch and the air circulation system leakage prevention protection switch respectively, and controls the indoor circulating fan (13), the outdoor unit (23), the heating circulating pump (32), the air energy heat pump (36), the heating proportional-integral valve (37) and the defrosting medium heating proportional-integral valve (47) in a feedback manner.

7. The control system of the low-temperature type constant-temperature and constant-humidity refrigerator unit according to claim 6, wherein the defrosting time of the surface cooler is set by a PLC to be controlled in a timing manner; after the defrosting time is up, the PLC control system starts a defrosting circulating pump (44) and opens a defrosting proportional-integral valve (41) to defrost the surface air cooler, the PLC control system is provided with double CPUs, when the master CPU fails, the system can be automatically switched to a standby CPU to ensure the normal operation of the system; the PLC control system is provided with double power supplies, and when the main power supply is powered off, the control system can be automatically switched to the standby power supply to supply power, so that the normal operation of the system is guaranteed.

8. The low-temperature type constant-temperature and constant-humidity refrigerator unit control system according to claim 7, characterized in that the refrigerator unit control system comprises more than two air circulation systems (1), and each air circulation system (1) is provided with one refrigerating system (2); the ethylene glycol heating system (3) is provided with two waste heat exchangers (35) and two air energy heat pumps (36); the two waste heat exchangers (35) are respectively arranged at the outdoor units (23) of the two refrigeration systems (2), and the two waste heat exchangers (35) are mutually parallel; the two air energy heat pumps (36) are arranged in parallel with each other and are arranged outside the refrigeration house.

9. The control system of the low-temperature type constant-temperature and constant-humidity refrigerator unit according to claim 8, wherein the waste heat exchanger (35), the air energy heat pump (36), the heating proportional-integral valve (37) and the heating medium tank (31) of the glycol heating system (3) are all arranged outside the refrigerator; a defrosting heat exchanger (45), a defrosting medium box (43), a defrosting proportional-integral valve (41) and a defrosting medium temperature control valve (47) of the defrosting system (4) are all arranged outside the refrigeration house.

10. The control system of the low-temperature constant-temperature and constant-humidity refrigerator unit according to claim 1, further comprising an equipment protection system, wherein the equipment protection system comprises a heater water level probe, an air channel water level probe and an outdoor unit high-low pressure protection switch; a sub waterproof tray is arranged right below the heating section (12), and a water level probe of the heater is arranged in the sub waterproof tray; a general waterproof tray is arranged below the air pipeline (14), and the air channel water level probe is arranged in the general waterproof tray; when any liquid level exceeds a set value, the indoor circulating system stops running and sends an alarm signal through the PLC control system to remind relevant personnel of overhauling; the outdoor unit high-low voltage protection switch is arranged in the outdoor unit (23), when the outdoor unit (23) detects that the compressor of the outdoor unit runs and high voltage or low voltage occurs, the outdoor unit (23) stops running, and an alarm signal is sent out through the PLC control system to remind relevant personnel of overhauling.

Background

The cold storage is mainly used for freezing processing and cold storage of foods, medicines, machinery and electronic products, and the cold storage keeps a certain low temperature indoors through artificial refrigeration; along with the development of economy, the construction of the refrigerator is more and more, the defrosting technology of the refrigerator is continuously improved, the heat exchange efficiency is improved, and the refrigerating capacity, the food quality and the like of equipment are directly influenced by the advantages and the disadvantages of the defrosting technology and the refrigerating technology. The continuous technological progress of scientific research personnel and enterprises improves the refrigeration house continuously from the aspects of improving the heat transfer efficiency of the refrigerating device, ensuring the efficient operation of the refrigerating device, having less investment, saving energy and the like.

At present, a conventional low-temperature constant-humidity refrigerator system is composed of: the refrigeration house indoor air circulation system, the low temperature refrigerating unit system and the rotary wheel dehumidifier unit system; there are the following problems: 1) the rotary dehumidifier unit system is complex, large in size, more in air pipes and large in occupied machine room area; 2) the auxiliary heat demand of the rotary wheel dehumidification unit is large, the energy consumption of the electric heating pipe is high, and a large amount of energy consumption is consumed; 3) the refrigeration and defrosting and the auxiliary heating of the rotary wheel dehumidification unit both adopt electric heating pipes, and the long-time operation is easy to cause fire due to line aging, so that the rotary wheel dehumidification unit has great potential safety hazard; 4) if the rotary wheel dehumidification unit needs a standby system, the investment cost is multiplied; 5) the main material consumption of the rotary wheel dehumidification unit is expensive, the order period is long, the maintenance difficulty is high, and the maintenance time is long.

Disclosure of Invention

The invention solves the problems that the refrigeration dehumidification system of the refrigeration house and the refrigeration house unit in the prior art have short service life, the parts are easy to damage and not easy to maintain, and the fireproof safety coefficient is low. The heat pump replaces electric heating, parts in the refrigeration house are simplified, more temperature control parts are arranged on the fire-proof level and the safety in the refrigeration house which is improved outdoors, the maintenance is convenient, the temperature control parts adopt the heating heat exchanger and the surface air cooler, and the refrigeration house has the characteristics of simple structure and long service life, so that the service life of the whole refrigeration house unit can be prolonged. By recycling waste heat of the refrigerating outdoor unit, the energy efficiency ratio of the refrigerator is improved in the operation process, and the operation cost of a user is reduced.

The technical scheme adopted by the invention for solving the technical problems is as follows:

a low-temperature type constant temperature and humidity freezer unit control system comprises:

the air circulation system comprises an air pipeline arranged in a refrigeration house, an air inlet and an air outlet of the air pipeline are both communicated with the indoor space of the refrigeration house, the air pipeline is divided into a surface cooling section, a heating section and a fan section, the surface cooling section is used for cooling air, the heating section is positioned on the air outlet side of the surface cooling section and is used for heating and controlling the temperature of the air, and a fan used for air circulation is arranged in the fan section;

the refrigeration system comprises a surface cooler, a refrigerant pipeline and an outdoor unit, wherein the surface cooler is arranged in a surface cooling section and used for air cooling, the outdoor unit is arranged outside the refrigeration house and used for heat dissipation, and the refrigerant pipeline is connected between the outdoor unit and the surface cooler and used for heat exchange between the outdoor unit and the surface cooler.

The ethylene glycol heating system comprises a heating heat exchange pipe, a heating medium box, a heating input pipeline and a heating return pipeline; the heating input pipeline and the heating return pipeline are connected between the heating heat exchange pipe and the heating medium box; a waste heat exchanger, an air energy heat pump and a heating proportional-integral valve are sequentially arranged on the heating input pipeline; the heating heat exchange pipe is arranged in the heating section and used for heating air; the waste heat exchanger is arranged in the outdoor unit and used for waste heat recovery, and the air energy heat pump is used for heating the input pipeline;

the defrosting system comprises a defrosting sprayer, a defrosting medium box, a defrosting water inlet pipeline and a defrosting water return pipeline; the defrosting water inlet pipeline and the defrosting water return pipeline are connected between the defrosting heat exchange pipe and the defrosting medium tank; a defrosting heat exchanger and a defrosting proportional-integral valve are arranged on the defrosting water inlet pipeline in sequence; the defrosting heat exchange pipe is connected with the heating input pipeline and is used for heating a medium in the defrosting water inlet pipeline; the defrosting sprayer is arranged in the surface cooling section and is used for spraying and defrosting the surface of the surface cooler;

the temperature and humidity sensing system comprises an indoor temperature and humidity probe, a surface cooling section temperature probe, a heating water temperature sensor and a defrosting water temperature sensor; the surface cooling section temperature probe is arranged on the surface cooler; the heating section temperature probe is arranged on the air outlet side of the heating heat exchanger; the heating water temperature sensor is arranged in the heating medium box; the defrosting water temperature sensor is arranged on the defrosting water inlet pipeline;

and the PLC control system is respectively and electrically connected with the temperature and humidity sensing system and controls the air circulation system, the refrigerating system, the glycol heating system and the defrosting system in a feedback manner.

Optionally, a waste heat control valve and a heating circulating pump are further arranged on the heating input pipeline, the waste heat control valve is connected to the water inlet side of the waste heat exchanger, the heating circulating pump is connected to the water outlet side of the heating medium tank, and the PLC control system is connected with and controls the waste heat control valve and the heating circulating pump.

Optionally, the defrosting heat exchanger includes a heat absorption channel and a heat release channel, two ends of the heat release channel are respectively connected to the heating input pipeline and the heating return pipeline, and two ends of the heat absorption channel are respectively connected to the defrosting water return pipeline and the defrosting water inlet pipeline.

Optionally, the water inlet side of the heat release channel is connected to the heating input pipeline through a defrosting medium temperature control valve; and the PLC control system is connected with and controls the opening degree of the defrosting medium temperature control valve.

Optionally, a defrosting circulating pump is arranged at an outlet of the defrosting medium tank, and the PLC control system is connected with and controls the start and stop of the defrosting circulating pump.

Optionally, the PLC control system is electrically connected to the indoor temperature and humidity probe, the surface cooling section temperature probe, the heating water temperature sensor, the defrosting water temperature sensor, the heater leakage prevention protection switch, the air circulation system leakage prevention protection switch, and the feedback control of the indoor circulation fan (13), the outdoor unit (23), the heating circulation pump (32), the air energy heat pump (36), the heating proportional-integral valve, and the defrosting medium heating proportional-integral valve, respectively.

Optionally, the defrosting time of the surface air cooler is set by the PLC for timing control; after the defrosting time is up, the PLC control system starts a defrosting circulating pump (44) and opens a defrosting proportional-integral valve (41) to defrost the surface air cooler, the PLC control system is provided with double CPUs, when the master CPU fails, the system can be automatically switched to a standby CPU to ensure the normal operation of the system; the PLC control system is provided with double power supplies, and when the main power supply is powered off, the control system can be automatically switched to the standby power supply to supply power, so that the normal operation of the system is guaranteed.

Optionally, the refrigeration storage unit control system comprises more than two air circulation systems, and each air circulation system is provided with a refrigeration system; the ethylene glycol heating system is provided with two waste heat exchangers and two air energy heat pumps; the two waste heat exchangers are respectively arranged at the outdoor units of the two refrigeration systems and are mutually parallel; the two air energy heat pumps are mutually parallel and arranged outside the refrigeration house.

Optionally, the waste heat exchanger, the air energy heat pump, the heating proportional-integral valve and the heating medium tank of the ethylene glycol heating system are all arranged outside the refrigeration house; and a defrosting heat exchanger, a defrosting medium box, a defrosting proportional-integral valve and a defrosting medium temperature control valve of the defrosting system are all arranged outside the refrigeration house.

Optionally, the control system of the refrigeration storage unit further comprises an equipment protection system, wherein the equipment protection system comprises a heater water level probe, an air channel water level probe and an outdoor unit high-low voltage protection switch; a sub waterproof tray is arranged right below the heating section, and a water level probe of the heater is arranged in the sub waterproof tray; a main waterproof tray is arranged below the air pipeline, and an air channel water level probe is arranged in the main waterproof tray; when any liquid level exceeds a set value, the indoor circulating system stops running and sends an alarm signal through the PLC control system to remind relevant personnel of overhauling; the outdoor unit high-low voltage protection switch is arranged in the outdoor unit (23), when the outdoor unit (23) detects that the compressor of the outdoor unit runs and high voltage or low voltage occurs, the outdoor unit (23) stops running, and an alarm signal is sent out through the PLC control system to remind relevant personnel of overhauling.

The invention has the beneficial effects that:

1. in the scheme, a dehumidification mode of condensing redundant moisture in the air on the surface of the surface cooler is adopted, a dehumidification mode of adopting a rotary dehumidifier in the prior art is replaced, the problems that a refrigeration house refrigeration dehumidification system and a refrigeration house unit in the prior art are short in service life and parts are easy to damage and difficult to maintain are solved, more temperature control parts are arranged outdoors by simplifying the parts in the refrigeration house, so that the maintenance is convenient, and the parts for controlling the temperature in the refrigeration house adopt heating heat exchange tubes and the surface cooler, so that the refrigeration house refrigeration dehumidification system has the characteristics of simple structure and long service life, and the service life of the whole refrigeration house unit can be prolonged;

2. the heating heat sources in the scheme are all in a pressurization heating mode, an electric heating mode is not directly used, and heat circulation adopts a heat exchanger structure, so that the waste heat and air heat energy can be fully utilized, the energy efficiency of the refrigeration house is improved, the operating cost of a user is reduced, the use of wearing parts such as an electric heater in the refrigeration house system can be avoided, the influence of the faults of an electric heating device on the service life and the use reliability of the refrigeration house system is avoided, and the fireproof safety coefficient of the refrigeration house is improved;

3. the defrosting heat exchanger in the scheme can directly exchange heat of heat in the glycol heating system to the defrosting system without adding other redundant heat sources, so that the use of an electric heater is further avoided, and defrosting is directly performed by using a medium spraying mode in a surface cooling section;

4. according to the scheme, a mode of heating water in the water tank is not adopted, but a real-time heating mode of the air heat energy pump is adopted, so that the loss in the heat energy storage process can be effectively avoided, the full utilization of heat is ensured, the real-time property of temperature control is increased, and the ethylene glycol heating system can adjust the temperature of the water through the power of the air energy heat pump; in addition, this scheme also does not adopt the electric heater direct heating air duct in the heating section, avoids the conflagration that this type of electrical apparatus circuit of heater caused, also avoids the frequent change of the difference in temperature to the damage of this type of vulnerable component of heater simultaneously.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a pipeline structure diagram of a low-temperature type constant-temperature and constant-humidity refrigerator set;

FIG. 2 is a connection detail structure diagram of a low-temperature type constant-temperature and constant-humidity refrigerator set;

FIG. 3 is a pipeline diagram of a refrigeration storage unit pipeline system added with standby equipment;

fig. 4 is a view showing a position structure of two waterproof trays in an air duct.

Reference numerals: 1-an air circulation system, 11-a surface cooling section, 12-a heating section, 13-a fan section, 14-an air pipeline, 15-a sub waterproof tray, 16-a total waterproof tray, 2-a refrigeration system, 21-a surface cooler, 22-a refrigerant pipeline, 23-an outdoor unit, a 3-ethylene glycol heating system, 31-a heating medium box, 32-a heating circulating pump, 33-a waste heat control valve, 34-a heating input pipeline, 35-a waste heat exchanger, 36-an air energy heat pump, 37-a heating proportional integral valve, 38-a heating return pipeline, 39-a heating heat exchange pipe, 4-a defrosting system, 41-a defrosting proportional integral valve, 42-a defrosting sprayer, 43-a defrosting medium box, 44-a defrosting circulating pump and 45-a defrosting heat exchanger, 46-defrosting return pipe, 47-defrosting medium temperature control valve.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1

As shown in fig. 1-4, the present embodiment designs a low-temperature type constant-temperature and constant-humidity freezer unit control system, which includes an air circulation system 1, a glycol heating system 3, a refrigeration system 2, a defrosting system 4, a temperature and humidity sensing system, and a PLC control system.

The air circulation system 1 comprises an air pipeline 14 and an indoor space of a refrigeration house, the air pipeline 14 is arranged in the refrigeration house, and an air inlet and an air outlet of the air pipeline are both communicated with the indoor space of the refrigeration house; along the conveying direction of air, this air conduit 14 can be divided into table cold section 11, heating section 12 and fan section 13, and table cold section 11 is used for the air cooling, and heating section 12 is located the play wind side of table cold section 11 and is used for the air heating accuse temperature, is provided with the fan that is used for air cycle in fan section 13.

The refrigeration system 2 comprises a surface air cooler 21, a refrigerant pipeline 22 and an outdoor unit 23, wherein the surface air cooler 21 is arranged in the surface air cooling section 11 and used for cooling air, the outdoor unit 23 is arranged outside the refrigeration house and used for dissipating heat, and the refrigerant pipeline 22 is connected between the outdoor unit 23 and the surface air cooler 21 and used for heat exchange between the outdoor unit 23 and the surface air cooler 21.

The glycol heating system 3 comprises a heating heat exchange pipe 39, a heating medium tank 31, a heating input pipe 34 and a heating return pipe 38; the heating heat exchange pipe 39 is arranged in the heating section 12 and used for heating air; the heating input pipeline 34 is connected between the heating medium tank 31 and the heating heat exchange pipe 39, and the heating input pipeline 34 is connected with the heating circulating pump 32, the waste heat control valve 33, the waste heat exchanger 35, the air energy heat pump 36 and the heating proportional-integral valve 37 in sequence. The heating return line 38 is connected between the heating medium tank 31 and the heating heat exchange tube 39 and serves to return water. The air energy heat pump 36 is used for heating water, and the heating circulating pump 32 is used for circulating water; the waste heat exchanger 35 is disposed in the outdoor unit 23 and used for recovering waste heat of the outdoor unit 23, the waste heat control valve 33 is connected to a water inlet side of the waste heat exchanger 35, and the heating circulation pump 32 is connected to a water outlet side of the heating medium tank 31. The medium in the glycol heating system 3 may be 25% glycol.

The defrosting system 4 comprises a defrosting sprayer 42, a defrosting medium box 43, a defrosting water inlet pipeline and a defrosting water return pipeline 46; the defrosting water inlet pipeline and the defrosting water return pipeline 46 are connected between the defrosting heat exchange pipe and the defrosting medium tank 43; a defrosting circulating pump 44, a defrosting heat exchanger 45 and a defrosting proportional-integral valve 41 are arranged on the defrosting water inlet pipeline in sequence; the defrosting heat exchange pipe is connected with the heating input pipeline 34 and is used for heating a medium in the defrosting water inlet pipeline; the defrosting shower 42 is provided at the surface cooling section 11, and is used for performing shower defrosting on the surface of the surface air cooler 21.

The defrosting heat exchanger 45 includes a heat absorption channel and a heat release channel, two ends of the heat release channel are respectively connected to the heating input pipeline 34 and the heating return pipeline 38, and two ends of the heat absorption channel are respectively connected to the defrosting water return pipeline 46 and the defrosting water inlet pipeline; the water inlet side of the heat release channel is connected to the heating input line 34 through a defrosting medium temperature control valve 47; the PLC control system is connected to and controls the degree of opening of the defrost medium temperature control valve 47.

A defrosting circulation pump 44 is arranged at the outlet of the defrosting medium tank 43, and the PLC control system is connected with and controls the start and stop of the defrosting circulation pump 44.

The temperature and humidity sensing system comprises an indoor temperature and humidity probe, an air outlet side temperature and humidity probe, a first water temperature sensor and a second water temperature sensor; the indoor temperature and humidity probe is arranged in the refrigeration house and is used for detecting the temperature and humidity in the refrigeration house; the air outlet side temperature and humidity probe is arranged in the fan section 13 and is positioned on the air outlet side of the fan; the air outlet side temperature and humidity probe is used for detecting the air supply temperature and humidity of the air pipeline 14; the first water temperature sensor is arranged on the water inlet side of the heating proportional-integral valve 37 and used for detecting the water inlet temperature of the heating proportional-integral valve 37; the second water temperature sensor is disposed on the water inlet side of the defrosting proportional-integral valve 41 to detect the water inlet temperature of the heating defrosting proportional-integral valve 41.

The PLC control system is respectively and electrically connected with an indoor temperature and humidity probe, a surface cooling section temperature probe, a heating water temperature sensor, a defrosting water temperature sensor, a heater anti-leakage protection switch and an air circulation system anti-leakage protection switch and controls an indoor circulation fan (13), an outdoor unit (23), a heating circulation pump (32), an air energy heat pump (36), a heating proportional integral valve and a defrosting medium heating proportional integral valve in a feedback manner; the defrosting time of the surface cooler is set by a PLC (programmable logic controller) for timing control; after the defrosting time is up, the PLC control system starts a defrosting circulating pump (44) and opens a defrosting proportional-integral valve (41) to defrost the surface air cooler, the PLC control system is provided with double CPUs, when the master CPU fails, the system can be automatically switched to a standby CPU to ensure the normal operation of the system; the PLC control system is provided with double power supplies, and when the main power supply is powered off, the control system can be automatically switched to the standby power supply to supply power, so that the normal operation of the system is guaranteed.

The PLC control system is in communication connection with the back-end console, and the back-end console can send parameter setting instructions to the PLC control system.

The parameter setting instruction comprises a time setting instruction and a temperature control instruction; the temperature control instruction comprises air supply temperature and humidity, defrosting temperature, indoor temperature and humidity and heating temperature; the PLC control system controls the opening of the thermal proportional integral valve, the defrosting proportional integral valve 41 or the defrosting medium temperature control valve 47 according to the temperature control instruction; the time setting instruction comprises timing action, timing or delay action and other instructions.

Example 2

As shown in fig. 2-4, on the basis of the structure of embodiment 1, a control system for a low-temperature constant-temperature and constant-humidity freezer unit includes more than two air circulation systems 1, each air circulation system 1 is provided with a refrigeration system 2; the ethylene glycol heating system 3 is provided with two parallel heating circulating pumps 32 and two parallel waste heat exchangers 35, and the two waste heat exchangers 35 are respectively arranged at the outdoor units 23 of the two refrigeration systems 2; two parallel air energy heat pumps 36 are located outside the freezer. The defrosting system 4 adopts two parallel defrosting circulating pumps 44, and a defrosting heat exchanger 45, a defrosting medium tank 43, a defrosting proportional-integral valve 41 and a defrosting medium temperature control valve 47 of the defrosting system 4 are all arranged outside the refrigeration house. The two waste heat exchangers 35 and the two air energy heat pumps 36 are respectively arranged in parallel, so that the fault tolerance rate of the equipment is improved, the heat exchangers are provided with the upper limit of the heat exchange speed, and the heat exchangers and the circulating pump are provided with the upper limit of the operation, so that the upper limit of the other heat exchanger can be reached, the other heat exchanger is used as a main parameter for temperature and humidity regulation, and the difficulty in controlling the temperature of the non-electric heating refrigeration house unit is reduced.

The control system of the refrigeration house machine set also comprises an equipment protection system, wherein the equipment protection system comprises a heater water level probe, an air channel water level probe and an outdoor unit high-low voltage protection switch; a sub waterproof tray 15 is arranged right below the heating section, and a water level probe of the heater is arranged in the sub waterproof tray 15; a general waterproof tray 16 is arranged below the air pipeline, and an air channel water level probe is arranged in the general waterproof tray 16; when any liquid level exceeds a set value, the indoor circulating system stops running and sends an alarm signal through the PLC control system to remind relevant personnel of overhauling; the outdoor unit high-low voltage protection switch is arranged in the outdoor unit (23), when the outdoor unit (23) detects that the compressor of the outdoor unit runs and high voltage or low voltage occurs, the outdoor unit (23) stops running, and an alarm signal is sent out through the PLC control system to remind relevant personnel of overhauling.

The above examples are merely examples for clarity of description and are not intended to limit the embodiments; other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. And obvious variations or modifications therefrom are intended to be within the scope of the invention.