A heat pump dryer detection system and method thereof

Abstract

The application discloses a heat pump drying machine detection system and method, and relates to the technical field of heat pump systems, which comprises the following: an inner temperature and humidity sensor arranged at an evaporator and a compressor; an outer temperature and humidity sensor arranged at a communication position of a heat pump drying machine and a drying chamber; a temperature loss model for simulating the temperature loss of air flowing in the heat pump drying machine through a condenser, the evaporator, a fan, and the inner and outer temperature and humidity sensors, and calculating the temperature loss generated by the condenser, the evaporator and the air flow; and a scheduling unit for determining the adjustment parameters of the condenser, the evaporator and the fan by combining the set temperature and humidity parameters of the control system and the temperature loss generated by the condenser, the evaporator and the air flow. The power of the evaporator and the condenser can be adjusted according to the set temperature of the heat pump drying machine control system when the frost and dirt on the evaporator and the condenser affect heat conduction.

Description

Technical Field

[0001] This invention relates to the field of heat pump system technology, specifically to a heat pump dryer testing system and method. Background Technology

[0002] Exceeding safety thresholds in temperature, humidity, and exhaust pressure of a heat pump dryer can pose a series of risks and problems to the equipment and operators: Excessive temperature: Temperatures exceeding safety thresholds may cause overheating, affecting drying efficiency, damaging the equipment, and potentially leading to fires or other safety accidents; Excessive humidity: High humidity can affect drying performance and may cause frost buildup inside the equipment, hindering normal operation; Excessive exhaust pressure: Excessive exhaust pressure may damage the exhaust system, even posing an explosion risk, and can also affect the equipment's energy efficiency.

[0003] Publication No. CN109282546B discloses a detection method and system for a heat pump dryer. The detection method includes an exhaust pressure detection device to detect the compressor's exhaust pressure value, and an exhaust temperature detection device to detect the compressor's exhaust temperature value; a judgment device to determine whether the exhaust pressure value is greater than or equal to an exhaust pressure safety threshold, and a judgment device to determine whether the exhaust temperature value is greater than or equal to an exhaust temperature safety threshold. A control device controls the operating status of the heat pump dryer based on the judgment results of the judgment device. The exhaust pressure detection device and the exhaust temperature detection device work together to detect the compressor's exhaust pressure and exhaust temperature values ​​in real time. When either the exhaust pressure value or the exhaust temperature value exceeds a set threshold, the control device controls the heat pump dryer to a shutdown state, preventing damage to the equipment caused by continued operation.

[0004] Heat pump dryers control air temperature through condensers and evaporators. However, condensers and evaporators can experience temperature losses, resulting in a difference between the set temperature of the dryer and the actual temperature inside the drying chamber.

[0005] Temperature control in heat pump dryers can be broadly categorized into two control methods:

[0006] Firstly, based on the set temperature, the condenser and evaporator change parameters such as power to make the air reach the corresponding temperature. However, after the condenser and evaporator are frosted or dirt accumulates, the temperature of the flowing air will be further and further away from the set temperature, resulting in a large difference between the final temperature entering the drying chamber and the set temperature.

[0007] Secondly, it tests the discharge temperature of the heat pump dryer. After the condenser and evaporator are frosted and dirt accumulates, they need to operate at higher power to reach the set discharge temperature. However, the condenser and evaporator may operate at full power, which will accelerate the wear and tear of the equipment and reduce its service life.

[0008] Therefore, simply measuring exhaust pressure and temperature cannot determine the temperature loss of the condenser and evaporator. Summary of the Invention

[0009] One of the objectives of this invention is to provide a heat pump dryer detection system and method, which determines the temperature loss of the condenser and evaporator during the operation of the heat pump dryer, and adjusts the condenser and evaporator according to the set temperature and the temperature loss changes.

[0010] To achieve the above objectives, the present invention is implemented through the following technical solution: a heat pump dryer detection system, wherein the heat pump dryer comprises a condenser for heating air, an evaporator for evaporating refrigerant, a compressor for compressing refrigerant, a fan for air flow, and a control system for controlling the operation of the condenser, evaporator, compressor, and fan, and the heat pump dryer is connected to the drying chamber;

[0011] The detection system includes:

[0012] An internal temperature and humidity sensor is installed at the evaporator and compressor to acquire air temperature and humidity data at the evaporator and compressor locations.

[0013] An external temperature and humidity sensor is installed at the connection point between the heat pump dryer and the drying chamber to acquire the outlet gas temperature and humidity data of the heat pump dryer.

[0014] The interaction unit interacts with the control system to obtain the operating parameters of the condenser, evaporator, and fan;

[0015] The processing unit calculates standard temperature and humidity data for the corresponding area based on the operating parameters of the condenser and evaporator.

[0016] The temperature loss model simulates the temperature loss of air flowing in a heat pump dryer by using a condenser, evaporator, fan, and internal and external temperature and humidity sensors, and calculates the temperature loss generated by the condenser, evaporator, and air flow respectively.

[0017] The scheduling unit determines the adjustment parameters of the condenser, evaporator, and fan by controlling the set temperature and humidity parameters of the system, combined with the temperature loss generated by the condenser, evaporator, and air flow.

[0018] Based on the operating parameters of the condenser, evaporator, and fan, the corresponding air temperature and humidity changes in each area are determined. The temperature variation loss of the condenser and evaporator is determined by combining the air temperature and humidity data detected by the internal temperature and humidity sensor. The flow temperature loss is calculated based on the air temperature and humidity data and the gas temperature and humidity data. Based on the temperature and humidity set by the control system, the adjustment parameters of the condenser, evaporator, and fan are determined by combining the temperature variation loss and the flow temperature loss.

[0019] In one or more embodiments of the present invention, air temperature and humidity data and outlet gas temperature and humidity data are used to generate temperature change curves, and the temperature curves record the operating parameters of the evaporator, condenser and fan corresponding to the temperature and humidity data.

[0020] In one or more embodiments of the present invention, standard temperature and humidity data corresponding to different power levels of the evaporator and condenser are calculated using power, air mass flow rate, and specific heat capacity.

[0021] Calculation of evaporator operating power corresponding to standard temperature data:

[0022]

[0023] Where, ΔT z It is the standard air temperature, Q z This refers to the evaporator power, measured in kW; m is the air mass flow rate, measured in kg / s; and c is the evaporator power. p It is the specific heat capacity of air, measured in kJ / kg·K;

[0024] Calculation of standard humidity data corresponding to evaporator operating power:

[0025]

[0026] Wherein, ΔW z It is the standard humidity of the air, h fg It is the latent heat of vaporization of water;

[0027] Calculation of condenser operating power corresponding to standard temperature data:

[0028]

[0029] Where, ΔT l It is the standard air temperature, Q l This refers to the evaporator power, measured in kW.

[0030] In one or more embodiments of the present invention, the temperature flow rate loss generated by the movement of air inside the heat pump dryer is calculated based on the fan operating parameters:

[0031]

[0032] Where ρ is air density, A is pipe cross-sectional area, v is air velocity, ΔP is pressure loss, and Q is volumetric flow rate.

[0033] In one or more embodiments of the present invention, the temperature loss model acquires air temperature and humidity data detected by the internal temperature and humidity sensor, and calculates the temperature loss due to temperature change between the air temperature and humidity data and the standard temperature and humidity data.

[0034] Evaporator temperature loss:

[0035] ΔT zs =ΔT z -ΔT z1 ;

[0036] Where, ΔT z1 The evaporator temperature data is detected by an internal temperature and humidity sensor.

[0037] Condenser temperature loss:

[0038] ΔT ls =ΔT l -ΔT l1 ;

[0039] Where, ΔT l1 This is condenser temperature data detected by an internal temperature and humidity sensor.

[0040] In one or more embodiments of the present invention, the control system sets the target drying temperature of the heat pump dryer and calculates the power of the condenser and evaporator based on temperature loss due to temperature variation:

[0041] Evaporator power: Q z，adj =Q z +(ΔT zs ·m·c p );

[0042] Condenser power: Q l，adj =Q l +(ΔT ls ·m·c p );

[0043] Evaporator power Q z,adj and condenser power Q l,adj The power required to reach the target drying temperature.

[0044] In one or more embodiments of the present invention, the airflow temperature loss is calculated using an internal temperature and humidity sensor and an external temperature and humidity sensor.

[0045] ΔT c =ΔT l1 -ΔT2;

[0046] Where ΔT2 is the outlet gas temperature data.

[0047] In one or more embodiments of the present invention, the compensation power of the condenser and the dryer is calculated based on the target drying temperature of the control system, and the compensation power is adjusted according to the operating parameters of the fan.

[0048] When the air velocity is high, the air mass flow rate increases, the power loss increases, the heat exchange efficiency improves, and the overall temperature loss is small;

[0049] When the air velocity is high, the air mass flow rate increases, the power loss increases, the heat exchange efficiency improves, and the overall temperature loss is large;

[0050] The appropriate compensation power is determined based on the airflow speed affected by the fan.

[0051] The compensation power is combined with the evaporator power and condenser power to determine the final adjustment parameters.

[0052] This application also provides a testing method for a heat pump dryer, used in the aforementioned heat pump dryer testing system, comprising the following steps:

[0053] The interactive unit obtains the power of the control system for controlling the condenser, evaporator, and fan;

[0054] It obtains air temperature and humidity data detected by the internal temperature and humidity sensor and outlet gas temperature and humidity data detected by the external temperature and humidity sensor.

[0055] Standard temperature and humidity data are calculated based on the power of the condenser and evaporator.

[0056] Calculate the temperature loss due to temperature changes in the condenser and evaporator;

[0057] The power required to reach the target drying temperature of the control system is calculated based on temperature loss due to temperature changes.

[0058] Calculate flow temperature loss;

[0059] The adjustment parameters of the condenser, evaporator and fan are calculated based on the flow temperature loss.

[0060] In one or more embodiments of the present invention, the limit temperature and power of the condenser and evaporator are set, and the maximum duration of the limit temperature and power is determined. The parameters of the condenser and evaporator can be adjusted individually or simultaneously.

[0061] Through the above technical solution, the present invention has the following beneficial effects:

[0062] 1. This application calculates the temperature loss of the evaporator and condenser inside the heat pump dryer. When frost and dirt appear on the evaporator and condenser and affect heat conduction, the power of the evaporator and condenser can be adjusted according to the set temperature of the heat pump dryer control system. Combined with the temperature loss generated by the fan driving the air flow, the drying temperature is ensured to be accurate.

[0063] 2. Based on the power of the evaporator and condenser, the ideal temperature that the evaporator and condenser can achieve at the corresponding power is calculated. The temperature and humidity data at the location of the evaporator and condenser are detected by the internal temperature and humidity sensor to determine the temperature loss of the condenser and evaporator and the impact of frost and dirt on the condenser and evaporator.

[0064] 3. Based on internal and external temperature and humidity sensors, the flow temperature loss caused by airflow is calculated, thereby enabling precise adjustment of the outlet air temperature of the heat pump dryer to ensure accurate outlet air temperature and thus ensure stable drying effect inside the drying chamber.

[0065] 4. Calculate the adjustment parameters of the condenser, evaporator, and fan based on the temperature loss of the condenser, the temperature loss of the evaporator, and the temperature loss of the air flow, and ensure the accuracy of the outlet temperature by changing the power of the evaporator, condenser, and fan.

[0066] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the written description and the accompanying drawings. Attached Figure Description

[0067] Figure 1 This is a schematic diagram showing the configuration positions of the internal and external temperature and humidity sensors of the present invention.

[0068] Figure 2 This is a schematic diagram of the detection system of the present invention;

[0069] In the diagram: 100 Evaporator, 200 Condenser, 300 Fan, 400 Compressor, 500 Drying Chamber, a Inner Temperature and Humidity Sensor, b Outer Temperature and Humidity Sensor. Detailed Implementation

[0070] The following describes several embodiments of the present invention with reference to the accompanying drawings. For clarity, many practical details will be described in the following description. However, it should be understood that these practical details are not intended to limit the invention. That is, in some embodiments of the invention, these practical details are not essential. And, where feasible, features of different embodiments can be used interchangeably.

[0071] Unless otherwise defined, all terms used herein (including technical and scientific terms) have their ordinary meanings, which are understandable to those skilled in the art. Furthermore, the definitions of the foregoing terms in commonly used dictionaries should be interpreted in the context of this specification as having the meaning consistent with the relevant field of this invention. Unless specifically defined, these terms will not be construed as having idealized or overly formal meanings.

[0072] This invention provides a heat pump dryer testing system for testing a heat pump dryer, obtaining the temperature loss of the condenser 200 and evaporator 100 during the operation of the heat pump dryer, and determining the power parameters of the condenser 200 and evaporator 100 based on the set temperature and temperature loss.

[0073] like Figure 1-2 As shown, in one embodiment, the heat pump dryer comprises a condenser 200 for heating air, an evaporator 100 for evaporating refrigerant, a compressor 400 for compressing refrigerant, a fan 300 for air flow, and a control system for controlling the operation of the condenser 200, evaporator 100, compressor 400 and fan 300, and the heat pump dryer is connected to a drying chamber 500.

[0074] The detection system includes:

[0075] An internal temperature and humidity sensor a is installed at the evaporator 100 and the compressor 400 to acquire air temperature and humidity data at the locations of the evaporator 100 and the compressor 400.

[0076] External temperature and humidity sensor b is installed at the connection point between the heat pump dryer and the drying chamber 500 to acquire the outlet gas temperature and humidity data of the heat pump dryer;

[0077] The interaction unit interacts with the control system to obtain the operating parameters of the condenser 200, evaporator 100, and fan 300.

[0078] The processing unit calculates the standard temperature and humidity data for the corresponding area based on the operating parameters of the condenser 200 and the evaporator 100.

[0079] The temperature loss model simulates the temperature loss of air flowing in the heat pump dryer using condenser 200, evaporator 100, fan 300, internal temperature and humidity sensor a, and external temperature and humidity sensor b, and calculates the temperature loss generated by condenser 200, evaporator 100, and air flow respectively.

[0080] The scheduling unit determines the adjustment parameters of the condenser 200, evaporator 100 and fan 300 by controlling the set temperature and humidity parameters of the control system, combined with the temperature loss generated by the condenser 200, evaporator 100 and air flow.

[0081] Based on the operating parameters of condenser 200, evaporator 100 and fan 300, the air temperature and humidity changes corresponding to each area are determined. Combined with the air temperature and humidity data detected by internal temperature and humidity sensor a, the temperature change loss of condenser 200 and evaporator 100 is determined. The flow temperature loss is calculated based on the air temperature and humidity data and the gas temperature and humidity data. Based on the temperature and humidity set by the control system, combined with the temperature change loss and the flow temperature loss, the adjustment parameters of condenser 200, evaporator 100 and fan 300 are determined.

[0082] In one feasible method, after air enters the dryer, three temperature change zones are created. The first zone is located at the evaporator 100, where hot, humid air flows over its surface, causing water vapor in the air to condense into water droplets and be discharged at a low temperature, thus cooling the air. The second zone is located at the condenser 200, where the cooled air enters and is blown by the fan 300, coming into contact with the high-temperature refrigerant, absorbing its heat, and rising in temperature. The third zone is located between the condenser 200 and the drying chamber 500, where temperature loss occurs during airflow, causing temperature changes.

[0083] The changes in the three temperature variation zones, the frost or dirt accumulation on the surface of evaporator 100, will reduce heat transfer efficiency and lead to temperature loss; the dirt or blockage on the surface of condenser 200 will reduce heat transfer efficiency and lead to temperature loss; the air movement speed corresponds to the rate of temperature change. Therefore, calculations are performed separately for the three temperature variation zones to ensure the accuracy of the adjustment of the operating parameters of evaporator 100, condenser 200 and fan 300.

[0084] The temperature loss of condenser 200 and evaporator 100 is considered. Adjustments to these temperature losses are made to ensure the condenser 200 and evaporator 100 reach the set temperature and humidity, thus guaranteeing the effectiveness of the heat pump dryer. Due to temperature losses, inconsistencies may occur between the internal and external temperatures of condenser 200 and evaporator 100. Determining these temperature losses allows for accurate monitoring of the internal temperature of condenser 200 and evaporator 100, preventing excessively high internal temperatures exceeding safety thresholds or continued heating even when the external temperature has not reached the set threshold, which could damage condenser 200 or evaporator 100.

[0085] In one embodiment, air temperature and humidity data and outlet gas temperature and humidity data are used to generate a temperature curve graph, which records the operating parameters of the evaporator 100, condenser 200 and fan 300 corresponding to the temperature and humidity data.

[0086] In one feasible approach, temperature and humidity data, along with the operating parameters of the evaporator 100, condenser 200, and fan 300, are used to generate a temperature variation curve. This curve allows for analysis of the temperature changes corresponding to the evaporator 100, condenser 200, and fan 300. Since the power of the evaporator 100 and condenser 200 affects the overall system efficiency, appropriate power matching ensures optimal heat exchange; excessively low or high power will reduce efficiency.

[0087] Increasing the power of evaporator 100 and condenser 200 usually increases energy consumption, but if drying efficiency can be significantly improved, the overall energy consumption may be reduced. Therefore, the temperature curve can be used to analyze the heating state and consider the overall energy consumption.

[0088] In one embodiment, standard temperature and humidity data corresponding to different power levels of the evaporator 100 and condenser 200 are calculated using power, air mass flow rate, and specific heat capacity.

[0089] Calculation of standard temperature data corresponding to evaporator operating power of 100:

[0090]

[0091] Where, ΔT z It is the standard air temperature, Q z The evaporator power is 100 kW, m is the air mass flow rate, and c is the air mass flow rate. p It is the specific heat capacity of air, measured in kJ / kg·K;

[0092] Calculation of standard humidity data corresponding to evaporator operating power of 100:

[0093]

[0094] Wherein, ΔW z It is the standard humidity of the air, h fg It is the latent heat of vaporization of water;

[0095] Calculation of standard temperature data corresponding to the operating power of a condenser of 200:

[0096]

[0097] Where, ΔT l It is the standard air temperature, Q l This refers to the evaporator's power rating of 100 kW.

[0098] In one feasible approach, standard temperature and humidity data are calculated using the power of the condenser 200 and the evaporator 100, without considering temperature losses caused by frost or dirt buildup in the condenser 200 and the evaporator 100. This allows for the determination of the temperature and humidity conditions that can be changed under ideal power conditions.

[0099] During the actual operation of the condenser 200 and evaporator 100, frost and dirt cause temperature loss. Therefore, the actual air temperature and humidity data differ from the standard temperature and humidity data. To ensure that the air temperature and humidity data can reach the set values, the condenser 200 and evaporator 100 need to output more power.

[0100] For example, the evaporator 100 has a power of 5kW, an air mass flow rate of 0.5kg / s, an air specific heat capacity of 1.005kJ / kg·K, and a latent heat of vaporization of 2257kJ / kg. The corresponding standard temperature and humidity data for the evaporator 100 are as follows:

[0101]

[0102]

[0103] In one embodiment, the temperature flow rate loss caused by the movement of air inside the heat pump dryer is calculated based on the operating parameters of the fan 300:

[0104]

[0105] Where ρ is air density, A is pipe cross-sectional area, v is air velocity, ΔP is pressure loss, and Q is volumetric flow rate.

[0106] In one feasible approach, air encounters resistance during flow, resulting in pressure drop and temperature changes. The greater the resistance, the more significant the temperature loss. By determining the corresponding temperature velocity loss through the change in air flow speed caused by the operation of fan 300, the impact of air temperature changes can be calculated more accurately. This allows for more precise calculation of the temperature loss of condenser 200 and evaporator 100 based on temperature and humidity.

[0107] For example, the airflow conditions are as follows:

[0108] Air density ρ = 1.2 kg / m³ 3 ;

[0109] The pipe cross-sectional area A = 0.1 m² 2 ;

[0110] Air velocity v = 5 m / s;

[0111] specific heat capacity of air cp =1005 J / kg·K;

[0112] Pipe length L = 10m;

[0113] Pipe diameter D = 0.1m;

[0114] Friction factor f = 0.02.

[0115] Air mass flow rate:

[0116] m=ρ·A·v=1.2·0.1·5=0.6kg / s;

[0117] Pressure loss:

[0118]

[0119] Power loss:

[0120] P loss =ΔP·Q=ΔP·A·v=0.6·0.5=0.3W;

[0121] Temperature flow rate loss:

[0122]

[0123] In one embodiment, the temperature loss model acquires the air temperature and humidity data detected by the internal temperature and humidity sensor a, and calculates the temperature loss due to temperature variation between the air temperature and humidity data and the standard temperature and humidity data.

[0124] Evaporator temperature loss 100:

[0125] ΔT zs =ΔT z -ΔT z1 ;

[0126] Where, ΔT z1 Temperature data of evaporator 100 detected by internal temperature and humidity sensor;

[0127] Condenser 200 temperature loss:

[0128] ΔT ls =ΔT l -ΔT l1 ;

[0129] Where, ΔT l1 The temperature data for the condenser 200 is detected by an internal temperature and humidity sensor.

[0130] In one feasible approach, by determining the temperature loss of the evaporator 100 and the temperature loss of the condenser 200, it is possible to calculate the temperature difference caused by frost and dirt accumulation in the evaporator 100 and the condenser 200 under the power of the evaporator 100 and the condenser 200, thereby obtaining the frost and dirt status of the evaporator 100 and the condenser 200.

[0131] In one embodiment, the control system sets the target drying temperature of the heat pump dryer and calculates the power of the condenser 200 and evaporator 100 based on temperature variation losses.

[0132] Evaporator power 100: Q z，adj =Q z +(ΔT zs ·m·c p );

[0133] 200 condenser power: Q l，adj =Q l +(ΔT ls ·m·c p );

[0134] Evaporator 100 power Q z,adj 200 power condenser Q l,adj The power required to reach the target drying temperature.

[0135] In this embodiment, based on the temperature loss caused by the effect of frost and dirt on the outer walls of the evaporator 100 and condenser 200 on heat conduction, the power of the evaporator 100 and condenser 200 is increased to compensate for the problem that the temperature of the condenser 200 and evaporator 100 cannot reach the target drying temperature due to frost and dirt. This ensures the drying effect of the heat pump dryer during operation and further achieves precise control of the drying temperature of the heat pump dryer.

[0136] When frost and dirt occur, the internal and external temperatures of the evaporator 100 and condenser 200 will differ. If the internal temperature of the condenser 200 is too high, it will cause damage to the equipment. Therefore, the outlet temperature output is achieved by switching between high power, that is, the evaporator 100 and condenser 200 operate at high power during the switching period.

[0137] Since the condenser 200 and the evaporator 100 correspond to two different areas, and the areas where the air flows are interconnected, temperature loss will also occur during the operation of the fan 300 and the air flow process, resulting in differences in the outlet gas temperature and data of the heat pump dryer. During the operation of the condenser 200 and the evaporator 100, the flow temperature loss caused by the air flow also needs to be considered.

[0138] In one embodiment, the airflow temperature loss is calculated using an internal temperature and humidity sensor a and an external temperature and humidity sensor b.

[0139] ΔT c =ΔT l1 -ΔT2;

[0140] Where ΔT2 is the outlet gas temperature data.

[0141] In one feasible approach, the airflow temperature loss from the condenser 200 to the outlet position is calculated to determine the heat loss of air between the condenser 200 and the drying chamber 500. Based on the heat loss, the power of the condenser 200 and the evaporator 100 is further adjusted to ensure that the outlet temperature of the heat pump dryer is consistent with the set temperature.

[0142] During operation, the temperature of the heat pump dryer varies across three distinct zones. The zones corresponding to the condenser 200 and evaporator 100 are affected by the power of the condenser 200 and evaporator 100. Frost and dirt buildup on the outer surfaces of the condenser 200 and evaporator 100 can lead to heat transfer and temperature loss. Furthermore, air loss also occurs during the flow of air within the heat pump dryer. Therefore, it is necessary to detect and calculate the temperature loss of the condenser 200 and evaporator 100, as well as the temperature loss during air flow, and adjust the power of the condenser 200, evaporator 100, and fan 300 based on the temperature loss to ensure accurate temperature control.

[0143] In one embodiment, the compensation power of the condenser 200 and the dryer is calculated based on the target drying temperature controlled by the system, and the compensation power is adjusted according to the operating parameters of the fan 300.

[0144] When the air velocity is high, the air mass flow rate increases, the power loss increases, the heat exchange efficiency improves, and the overall temperature loss is small;

[0145] When the air velocity is high, the air mass flow rate increases, the power loss increases, the heat exchange efficiency improves, and the overall temperature loss is large;

[0146] The corresponding compensation power is determined based on the airflow speed affected by the fan 300.

[0147] The compensation power is combined with the power of evaporator 100 and condenser 200 to determine the final adjustment parameters.

[0148] In one feasible approach, the airflow velocity affects the amount of temperature loss. Accordingly, when the condenser 200 and evaporator 100 cannot be increased too much to ensure the outlet temperature, the airflow velocity is adjusted by changing the power of the fan 300 to achieve a stable outlet temperature.

[0149] This application also provides a testing method for a heat pump dryer, used in the aforementioned heat pump dryer testing system, comprising the following steps:

[0150] The interactive unit obtains the power of the control system to control the condenser 200, evaporator 100 and fan 300;

[0151] The system obtains air temperature and humidity data detected by internal temperature and humidity sensor a and outlet gas temperature and humidity data detected by external temperature and humidity sensor b.

[0152] Standard temperature and humidity data are calculated based on the power of condenser 200 and evaporator 100.

[0153] Calculate the temperature loss due to temperature changes in condenser 200 and evaporator 100;

[0154] The power required to reach the target drying temperature of the control system is calculated based on temperature loss due to temperature changes.

[0155] Calculate flow temperature loss;

[0156] The adjustment parameters of condenser 200, evaporator 100 and fan 300 are calculated based on the flow temperature loss.

[0157] In one embodiment, the limiting temperature and power of the condenser 200 and the evaporator 100 are set, and the maximum duration of the limiting temperature and power is determined. The parameters of the condenser 200 and the evaporator 100 can be adjusted individually or simultaneously.

[0158] In summary, the technical solutions disclosed in the above embodiments of the present invention have at least the following advantages:

[0159] 1. This application calculates the temperature loss of the evaporator and condenser inside the heat pump dryer. When frost and dirt appear on the evaporator and condenser and affect heat conduction, the power of the evaporator and condenser can be adjusted according to the set temperature of the heat pump dryer control system. Combined with the temperature loss generated by the fan driving the air flow, the drying temperature is ensured to be accurate.

[0160] 2. Based on the power of the evaporator and condenser, the ideal temperature that the evaporator and condenser can achieve at the corresponding power is calculated. The temperature and humidity data at the location of the evaporator and condenser are detected by the internal temperature and humidity sensor to determine the temperature loss of the condenser and evaporator and the impact of frost and dirt on the condenser and evaporator.

[0161] 3. Based on internal and external temperature and humidity sensors, the flow temperature loss caused by airflow is calculated, thereby enabling precise adjustment of the outlet air temperature of the heat pump dryer to ensure accurate outlet air temperature and thus ensure stable drying effect inside the drying chamber.

[0162] 4. Calculate the adjustment parameters of the condenser, evaporator, and fan based on the temperature loss of the condenser, the temperature loss of the evaporator, and the temperature loss of the air flow, and ensure the accuracy of the outlet temperature by changing the power of the evaporator, condenser, and fan.

[0163] Although the present invention has been disclosed in conjunction with the above embodiments, it is not intended to limit the present invention. Any person skilled in the art can make various modifications and refinements without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be defined by the appended claims.

Claims

1. A detection system for a heat pump dryer, wherein the heat pump dryer comprises a condenser for heating air, an evaporator for evaporating refrigerant, a compressor for compressing refrigerant, a fan for air flow, and a control system for controlling the operation of the condenser, evaporator, compressor, and fan, and the heat pump dryer is connected to a drying chamber; characterized in that, The detection system includes: An internal temperature and humidity sensor is installed at the evaporator and compressor to obtain air temperature and humidity data inside the evaporator and compressor. An external temperature and humidity sensor is installed at the connection point between the heat pump dryer and the drying chamber to acquire the outlet gas temperature and humidity data of the heat pump dryer. The interaction unit interacts with the control system to obtain the operating parameters of the condenser, evaporator, and fan; The processing unit calculates standard temperature and humidity data for the corresponding area based on the operating parameters of the condenser and evaporator. The temperature loss model simulates the temperature loss of air flowing in a heat pump dryer by using a condenser, evaporator, fan, and internal and external temperature and humidity sensors, and calculates the temperature loss generated by the condenser, evaporator, and air flow respectively. The scheduling unit determines the adjustment parameters of the condenser, evaporator, and fan by controlling the set temperature and humidity parameters of the system, combined with the temperature loss generated by the condenser, evaporator, and air flow. Air temperature and humidity data, as well as outlet gas temperature and humidity data, generate a temperature change curve. The temperature curve records the operating parameters of the evaporator, condenser, and fan corresponding to the temperature and humidity data. The standard temperature and humidity data corresponding to different power ratings of the evaporator and condenser are calculated using power, air mass flow rate, and specific heat capacity. Calculation of evaporator operating power corresponding to standard temperature data: ； Where, ΔT z It is the standard air temperature, Q z This refers to the evaporator power, measured in kW; m is the air mass flow rate, measured in kg / s; and c is the evaporator power. p It is the specific heat capacity of air, measured in kJ / kg·K; Calculation of standard humidity data corresponding to evaporator operating power: ； Wherein, ΔW z It is the standard humidity of the air, h fg It is the latent heat of vaporization of water; Calculation of condenser operating power corresponding to standard temperature data: ； Where, ΔT l It is the standard air temperature, Q l This refers to the evaporator power, measured in kW.

2. The heat pump dryer detection system according to claim 1, characterized in that, Calculation of temperature and velocity losses caused by air movement inside the heat pump dryer based on fan operating parameters: ； in, Here, A is the air density, A is the cross-sectional area of ​​the pipe, and v is the air velocity. Q is pressure loss, and Q is volumetric flow rate.

3. The heat pump dryer detection system according to claim 2, characterized in that, The temperature loss model acquires air temperature and humidity data detected by the internal temperature and humidity sensor, and calculates the temperature loss due to temperature variation between the air temperature and humidity data and the standard temperature and humidity data. Evaporator temperature loss: ； Where, ΔT z1 The evaporator temperature data is detected by an internal temperature and humidity sensor. Condenser temperature loss: ； Where, ΔT l1 This is condenser temperature data detected by an internal temperature and humidity sensor.

4. The heat pump dryer detection system according to claim 3, characterized in that, The control system sets the target drying temperature for the heat pump dryer and calculates the power of the condenser and evaporator based on temperature-varying losses. Evaporator power: ; Condenser power: ; Evaporator power Q z,adj and condenser power Q l,adj The power required to reach the target drying temperature.

5. The heat pump dryer detection system according to claim 4, characterized in that, Airflow temperature loss is calculated using internal and external temperature and humidity sensors. ； Where ΔT2 is the outlet gas temperature data.

6. A method for testing a heat pump dryer, used in the heat pump dryer testing system as described in claim 5, characterized in that, Includes the following steps: The interactive unit obtains the power of the control system for controlling the condenser, evaporator, and fan; It obtains air temperature and humidity data detected by the internal temperature and humidity sensor and outlet gas temperature and humidity data detected by the external temperature and humidity sensor. Standard temperature and humidity data are calculated based on the power of the condenser and evaporator. Calculate the temperature loss due to temperature changes in the condenser and evaporator; The power required to reach the target drying temperature of the control system is calculated based on temperature loss due to temperature changes. Calculate flow temperature loss; The adjustment parameters of the condenser, evaporator and fan are calculated based on the flow temperature loss.

7. The method for testing a heat pump dryer according to claim 6, characterized in that, Set the limit temperature and power of the condenser and evaporator, and determine the maximum duration of the limit temperature and power. The parameters of the condenser and evaporator can be adjusted individually or simultaneously.

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