Real ship energy efficiency measuring system and method for marine refrigeration system

Abstract

The invention relates to a real ship energy efficiency measuring system and method for a marine refrigeration system. The system comprises a refrigerating unit, a plurality of refrigerators, a cooling water inlet pipe, a cooling water outlet pipe, a first cooling water temperature measuring device, a second cooling water temperature measuring device, a cooling water flow measuring device and a control box. The first cooling water temperature measuring device and the second cooling water temperature measuring device are respectively arranged on the cooling water inlet pipe and the cooling water outlet pipe, and the distance between the first cooling water temperature measuring device and the second cooling water temperature measuring device and the upstream straight pipe is larger than or equal to 4.5 De-7.5 De; the cooling water flow measuring device is arranged on the cooling water outlet pipe, the distance between the cooling water flow measuring device and the upstream straight pipe is larger than or equal to 9 De-12 De, and the distance between the cooling water flow measuring device and the downstream straight pipe is larger than or equal to 4.5 De-7.5 De. In the application, by reasonably arranging the layout position of the measuring device, the measured data deviation caused by the deviation of the test point layout is avoided, the accuracy of the energy efficiency calculation result of the refrigerating system is ensured, and meanwhile, the position of the measuring device can adapt to different refrigerating pipelines, so that the measuring device has a wide application range. Therefore, the method is high in accuracy and good in adaptability.

Description

Technical Field

[0001] The invention relates to energy efficiency measurement means, belongs to the field of marine energy efficiency, and in particular to a real ship energy efficiency measurement system and method for a marine refrigeration system. Background Art

[0002] The distribution of marine refrigeration systems is complex and high-power. They consume a lot of electricity when used on board. The electricity on board is generated by burning fuel in marine auxiliary engines. By improving the energy efficiency of refrigeration units, it is possible to reduce fuel consumption, reduce ship operating costs, and reduce harmful gas emissions. Therefore, improving the energy efficiency of refrigeration systems and reducing the energy consumption of marine refrigeration systems are crucial for energy conservation and emission reduction of ships.

[0003] In the prior art, the energy efficiency test of marine refrigeration systems usually adopts the method of comparing the input power with the cooling capacity generated by the refrigerant. However, this method is relatively simple and can only provide a rough efficiency range. It does not fully consider the distribution differences of refrigeration pipelines on different ship types, as well as the impact of different refrigerant types and their states on system performance. As a result, the accuracy and convenience of the test results are limited, and not only the accuracy is low, but also the scope of application is limited.

[0004] The patent application document with application date of June 6, 2018 and application number 201810577108.5 discloses a method for measuring the energy efficiency of a natural ventilation countercurrent wet cooling tower, which calculates the energy efficiency evaluation index by obtaining the structural parameters and operating parameters of the cooling tower and completes the energy efficiency evaluation; although the scheme can perform energy efficiency evaluation, the scheme can only be performed for natural ventilation countercurrent wet cooling towers, and cannot achieve self-adaptation for the refrigeration pipelines of different ship types, and cannot solve the above-mentioned defects existing in the prior art. Summary of the invention

[0005] The purpose of the present invention is to overcome the defects and problems of low accuracy and poor adaptability in the prior art, and to provide a real ship energy efficiency measurement system and method for a marine refrigeration system with high accuracy and good adaptability.

[0006] To achieve the above objectives, the technical solution of the present invention is: a real ship energy efficiency measurement system for a marine refrigeration system, the refrigeration system comprising a refrigeration unit, a plurality of cold storages, a cooling water inlet pipe, and a cooling water outlet pipe; a plurality of the cold storages are provided with a cooling fan and a temperature measuring device;

[0007] The measurement system includes a first cooling water temperature measuring device, a second cooling water temperature measuring device, a cooling water flow measuring device, and a control box; the control box is electrically connected to the refrigeration unit, and a first voltage and current measuring device, a second voltage and current measuring device, and a power factor measuring device are arranged in the control box; the cooling water inlet pipe and the cooling water outlet pipe are both connected to the refrigeration unit, and the refrigeration unit is connected to a plurality of cold storages;

[0008] The first cooling water temperature measuring device is arranged on the straight water inlet section of the cooling water inlet pipe; the first cooling water temperature measuring device is ≥4.5De-7.5De away from the upstream straight pipe section of the straight water inlet section, and ≥1.5De-4De away from the downstream straight pipe section of the straight water inlet section;

[0009] The second cooling water temperature measuring device and the cooling water flow measuring device are arranged on the water outlet straight pipe section of the cooling water outlet pipe; the second cooling water temperature measuring device is ≥4.5De-7.5De away from the upstream straight pipe length of the water outlet straight pipe section, and is ≥1.5De-4De away from the downstream straight pipe length of the water outlet straight pipe section; the cooling water flow measuring device 7 is ≥9De-12De away from the upstream straight pipe length of the water outlet straight pipe section, and is ≥4.5De-7.5De away from the downstream straight pipe length of the water outlet straight pipe section.

[0010] The temperature measuring device is arranged at the rear side of the air cooler, 200mm-300mm away from the air cooler, 100mm-200mm away from the rear plate of the cold storage, and 400mm-600mm away from the top plate of the cold storage.

[0011] The first cooling water temperature measuring device is ≥5De away from the upstream straight pipe section of the water inlet straight pipe section, and ≥2De away from the downstream straight pipe section of the water inlet straight pipe section;

[0012] The distance between the second cooling water temperature measuring device and the upstream straight pipe section of the water outlet is ≥5De, and the distance between the second cooling water temperature measuring device and the downstream straight pipe section of the water outlet is ≥2De;

[0013] The cooling water flow measurement device is ≥10De from the upstream straight pipe length of the water outlet straight pipe section, and ≥5De from the downstream straight pipe length of the water outlet straight pipe section.

[0014] A method for measuring the energy efficiency of a real ship for a marine refrigeration system, the method comprising:

[0015] S1, setting the measurement section positions of the first cooling water temperature measuring device and the second cooling water temperature measuring device;

[0016] The measuring section of the first cooling water temperature measuring device is set at a distance of ≥4.5De-7.5De from the upstream straight pipe section of the water inlet straight pipe section, and ≥1.5De-4De from the downstream straight pipe section of the water inlet straight pipe section;

[0017] The measuring section of the second cooling water temperature measuring device is set at a distance of ≥5De-7.5De from the upstream straight pipe section of the water outlet straight pipe section, and ≥2De-4De from the downstream straight pipe section of the water outlet straight pipe section;

[0018] S2. Setting the measuring section position of the cooling water flow measuring device;

[0019] The measuring section of the cooling water flow measuring device is set at a distance of ≥9De-12De from the upstream straight pipe section of the water outlet straight pipe section, and ≥4.5De-7.5De from the downstream straight pipe section of the water outlet straight pipe section;

[0020] S3, setting a temperature measuring device and obtaining the temperatures in several cold storages; if the temperatures in the several cold storages all meet the preset measurement temperature, proceed to step S4;

[0021] S4, obtaining the cooling water inlet temperature and outlet temperature based on the first cooling water temperature measuring device and the second cooling water temperature measuring device; obtaining the cooling water flow rate based on the cooling water flow measuring device; obtaining the motor working voltage and current based on the first voltage and current measuring device and the second voltage and current measuring device; obtaining the power factor based on the power factor measuring device;

[0022] S5. Based on the energy efficiency calculation formula, calculate the energy efficiency of the refrigeration system; the calculation expression is as follows:

[0023]

[0024] Where: η is the energy efficiency of the refrigeration system, Q is the output cooling capacity, P in is the input power;

[0025] S6. Based on steps S4-S5, repeatedly obtain the energy efficiency η of the refrigeration system several times 1 , η 2 ,…,η n , and calculate the comprehensive average energy efficiency of the refrigeration system; the calculation formula of the average energy efficiency is as follows:

[0026]

[0027] Where: η 平均 is the comprehensive average energy efficiency of the refrigeration system, and n is the number of times the energy efficiency of the refrigeration system is obtained.

[0028] The input power P in The calculation formula is as follows:

[0029]

[0030] Among them: U n is the input working voltage of the nth air cooler, In is the average working current of the motor of the nth air cooler, is the power factor;

[0031] The calculation formula of the output cooling capacity Q is as follows:

[0032] Q=Q w -P in ;

[0033] Where: Q w The heat removed by cooling water;

[0034] Q w =C*m*(t out -t in );

[0035] Where: C is the specific heat of water, m is the cooling water flow rate, t out is the cooling water outlet temperature, t in is the cooling water inlet temperature.

[0036] The measuring section of the first cooling water temperature measuring device is set at a distance of ≥5De from the upstream straight pipe section of the water inlet straight pipe section and ≥2De from the downstream straight pipe section of the water inlet straight pipe section;

[0037] The measuring section of the second cooling water temperature measuring device is set at a distance of ≥5De from the upstream straight pipe section of the water outlet straight pipe section and ≥2De from the downstream straight pipe section of the water outlet straight pipe section;

[0038] The measuring section of the cooling water flow measuring device is set at a distance of ≥10De from the upstream straight pipe length of the water outlet straight pipe section and ≥5De from the downstream straight pipe length of the water outlet straight pipe section.

[0039] In step S3, the temperature measuring device is arranged at the rear side of the air cooler, and the distance from the air cooler is ≥

[0040] 200mm, and ≥100mm from the rear plate of the cold storage, and ≥500mm from the top plate of the cold storage.

[0041] Compared with the prior art, the present invention has the following beneficial effects:

[0042] 1. In a real ship energy efficiency measurement system and method for a marine refrigeration system of the present invention, the system includes a refrigeration unit, several cold storages, a cooling water inlet pipe, a cooling water outlet pipe, a first and a second cooling water temperature measuring device, a cooling water flow measuring device, and a control box; the first and the second cooling water temperature measuring devices are respectively arranged on the cooling water inlet pipe and the cooling water outlet pipe, and the distance from the upstream straight pipe length is ≥4.5De-7.5De, and the distance from the downstream straight pipe length is ≥1.5De-4De; the cooling water flow measuring device is arranged on the cooling water outlet pipe, and the distance from the upstream straight pipe length is ≥9De-12De, and the distance from the downstream straight pipe length is ≥4.5De-7.5De; in the application of this design, by reasonably setting the layout position of the measuring device, the measurement data deviation caused by the deviation of the test point layout is avoided, so that the measurement data obtained by this scheme is more accurate, thereby ensuring the accuracy of the refrigeration system energy efficiency calculation results, and at the same time, the position of the measuring device can adapt to different refrigeration pipelines, without considering the differences between different refrigeration pipelines, so that it has a wider range of application. Therefore, the present invention is not only highly accurate but also has good adaptability.

[0043] 2. In the actual ship energy efficiency measurement system and method for a marine refrigeration system of the present invention, the temperature measuring device is arranged at the side and rear of the air cooler, 200mm-300mm away from the air cooler, 100mm-200mm away from the rear plate of the cold storage, and 400mm-600mm away from the top plate of the cold storage; in the application of this design, the temperature measuring device is arranged near the return air outlet of the air cooler to monitor the temperature in the cold storage, and the temperature field here is uniform, which can accurately reflect the comprehensive temperature in the storage. Therefore, the accuracy of the present invention is relatively high.

[0044] 3. In the present invention, a real ship energy efficiency measurement system and method for a marine refrigeration system not only considers the relationship between input power and output cooling capacity during calculation, but also fully considers the accuracy and convenience of the test when there are multiple cold storages, so as to more comprehensively analyze the impact of different factors on the energy efficiency of the refrigeration system, better reflect the actual situation, and more conveniently calculate the energy efficiency of the refrigeration system. Therefore, the energy efficiency calculation of the present invention is more convenient. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 It is a schematic diagram of the system structure of the present invention.

[0046] Figure 2 It is a schematic diagram of the relative positions of the cooling water flow measurement device of the present invention.

[0047] Figure 3 It is a schematic diagram of the relative positions of the first and second cooling water temperature measuring devices of the present invention.

[0048] Figure 4This is one of the relative position schematic diagrams of the temperature measuring device of the present invention.

[0049] Figure 5 This is the second schematic diagram of the relative position of the temperature measuring device of the present invention.

[0050] In the figure: a refrigeration unit 1, several cold storages 2, an air cooler 21, a temperature measuring device 22, a rear storage plate 23, a storage top plate 24, a cooling water inlet pipe 3, a water inlet straight pipe section 31, a cooling water outlet pipe 4, a water outlet straight pipe section 41, a first cooling water temperature measuring device 5, a second cooling water temperature measuring device 6, a cooling water flow measuring device 7, a control box 8, a first voltage and current measuring device 81, a second voltage and current measuring device 82, and a power factor measuring device 83. DETAILED DESCRIPTION

[0051] The present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0052] A real ship energy efficiency measurement system for a marine refrigeration system, the refrigeration system comprising a refrigeration unit 1, a plurality of cold storages 2, a cooling water inlet pipe 3, and a cooling water outlet pipe 4; a plurality of the cold storages 2 are each provided with a cooling fan 21 and a temperature measuring device 22;

[0053] The measuring system includes a first cooling water temperature measuring device 5, a second cooling water temperature measuring device 6, a cooling water flow measuring device 7, and a control box 8; the control box 8 is electrically connected to the refrigeration unit 1, and a first voltage and current measuring device 81, a second voltage and current measuring device 82, and a power factor measuring device 83 are arranged in the control box 8; the cooling water inlet pipe 3 and the cooling water outlet pipe 4 are both connected to the refrigeration unit 1, and the refrigeration unit 1 is connected to a plurality of cold storages 2;

[0054] The first cooling water temperature measuring device 5 is arranged on the water inlet straight pipe section 31 of the cooling water inlet pipe 3; the first cooling water temperature measuring device 5 is ≥4.5De-7.5De away from the upstream straight pipe section 31, and ≥1.5De-4De away from the downstream straight pipe section 31;

[0055] The second cooling water temperature measuring device 6 and the cooling water flow measuring device 7 are arranged on the water outlet straight pipe section 41 of the cooling water outlet pipe 4; the second cooling water temperature measuring device 6 is ≥4.5De-7.5De away from the upstream straight pipe length of the water outlet straight pipe section 41, and is ≥1.5De-4De away from the downstream straight pipe length of the water outlet straight pipe section 41; the cooling water flow measuring device 7 is ≥9De-12De away from the upstream straight pipe length of the water outlet straight pipe section 41, and is ≥4.5De-7.5De away from the downstream straight pipe length of the water outlet straight pipe section 41.

[0056] The temperature measuring device 22 is arranged at the rear side of the air cooler 21, 200mm-300mm away from the air cooler, 100mm-200mm away from the rear plate of the cold storage 2, and 400mm-600mm away from the top plate of the cold storage 2.

[0057] The first cooling water temperature measuring device 5 is ≥5De away from the upstream straight pipe section 31 of the water inlet straight pipe section, and ≥2De away from the downstream straight pipe section 31 of the water inlet straight pipe section;

[0058] The distance between the second cooling water temperature measuring device 6 and the upstream straight pipe section 41 is ≥5De, and the distance between the second cooling water temperature measuring device 6 and the downstream straight pipe section 41 is ≥2De;

[0059] The cooling water flow measurement device 7 is ≥10De away from the upstream straight pipe section 41 of the water outlet straight pipe section, and ≥5De away from the downstream straight pipe section 41 of the water outlet straight pipe section.

[0060] A method for measuring the energy efficiency of a real ship for a marine refrigeration system, the method comprising:

[0061] S1, setting the measurement section positions of the first cooling water temperature measuring device 5 and the second cooling water temperature measuring device 6;

[0062] The measuring section of the first cooling water temperature measuring device 5 is set at a distance of ≥4.5De-7.5De from the upstream straight pipe section 31 and ≥1.5De-4De from the downstream straight pipe section 31;

[0063] The measuring section of the second cooling water temperature measuring device 6 is set at a distance of ≥5De-7.5De from the upstream straight pipe section 41 of the water outlet straight pipe section, and ≥2De-4De from the downstream straight pipe section 41 of the water outlet straight pipe section;

[0064] S2, setting the measurement section position of the cooling water flow measurement device 7;

[0065] The measuring section of the cooling water flow measuring device 7 is set at a distance of ≥9De-12De from the upstream straight pipe section 41 of the water outlet straight pipe section, and ≥4.5De-7.5De from the downstream straight pipe section 41 of the water outlet straight pipe section;

[0066] S3, setting a temperature measuring device 22 and obtaining the temperatures in the plurality of cold storages 2; if the temperatures in the plurality of cold storages 2 all meet the preset measurement temperature, proceeding to step S4;

[0067] S4, based on the first cooling water temperature measuring device 5 and the second cooling water temperature measuring device 6, obtain the cooling water inlet temperature and outlet temperature; based on the cooling water flow measuring device 7, obtain the cooling water flow; based on the first voltage and current measuring device 81 and the second voltage and current measuring device 82, obtain the motor working voltage and current; based on the power factor measuring device 83, obtain the power factor;

[0068] S5. Based on the energy efficiency calculation formula, calculate the energy efficiency of the refrigeration system; the calculation expression is as follows:

[0069]

[0070] Where: η is the energy efficiency of the refrigeration system, Q is the output cooling capacity, P in is the input power;

[0071] S6. Based on steps S4-S5, repeatedly obtain the energy efficiency η of the refrigeration system several times 1 , η 2 ,…,η n , and calculate the comprehensive average energy efficiency of the refrigeration system; the calculation formula of the average energy efficiency is as follows:

[0072]

[0073] Where: η 平均 is the comprehensive average energy efficiency of the refrigeration system, and n is the number of times the energy efficiency of the refrigeration system is obtained.

[0074] The input power P in The calculation formula is as follows:

[0075]

[0076] Among them: U n is the input working voltage of the nth air cooler, I n is the average working current of the motor of the nth air cooler, is the power factor;

[0077] The calculation formula of the output cooling capacity Q is as follows:

[0078] Q=Q w -P in ;

[0079] Where: Q w Heat removed by cooling water;

[0080] Q w =C*m*(t out -t in );

[0081] Where: C is the specific heat of water, m is the cooling water flow rate, tout is the cooling water outlet temperature, t in is the cooling water inlet temperature.

[0082] The measuring section of the first cooling water temperature measuring device 5 is set at a distance of ≥5De from the upstream straight pipe section 31 and ≥2De from the downstream straight pipe section 31;

[0083] The measuring section of the second cooling water temperature measuring device 6 is set at a distance of ≥5De from the upstream straight pipe section 41 of the water outlet straight pipe section, and ≥2De from the downstream straight pipe section 41 of the water outlet straight pipe section;

[0084] The measuring section of the cooling water flow measuring device 7 is set at a distance of ≥10De from the upstream straight pipe section 41 and ≥5De from the downstream straight pipe section 41 .

[0085] In step S3, the temperature measuring device 22 is arranged at the rear side of the air cooler 21, at a distance of ≥200 mm from the air cooler 21, at a distance of ≥100 mm from the rear panel 23 of the cold storage 2, and at a distance of ≥500 mm from the top panel 24 of the cold storage 2.

[0086] Embodiment 1:

[0087] See also Figure 1 A real ship energy efficiency measurement system for a marine refrigeration system, the refrigeration system comprising a refrigeration unit 1, a plurality of cold storages 2, a cooling water inlet pipe 3, and a cooling water outlet pipe 4; a plurality of the cold storages 2 are each provided with a cooling fan 21 and a temperature measuring device 22;

[0088] The measuring system includes a first cooling water temperature measuring device 5, a second cooling water temperature measuring device 6, a cooling water flow measuring device 7, and a control box 8; the control box 8 is electrically connected to the refrigeration unit 1, and a first voltage and current measuring device 81, a second voltage and current measuring device 82, and a power factor measuring device 83 are arranged in the control box 8; the cooling water inlet pipe 3 and the cooling water outlet pipe 4 are both connected to the refrigeration unit 1, and the refrigeration unit 1 is connected to a plurality of cold storages 2;

[0089] The first cooling water temperature measuring device 5 is arranged on the water inlet straight pipe section 31 of the cooling water inlet pipe 3; the first cooling water temperature measuring device 5 is ≥4.5De-7.5De (preferably ≥5De) away from the upstream straight pipe section 31, and ≥1.5De-4De (preferably ≥2De) away from the downstream straight pipe section 31;

[0090] The second cooling water temperature measuring device 6 and the cooling water flow measuring device 7 are arranged on the water outlet straight pipe section 41 of the cooling water outlet pipe 4; the second cooling water temperature measuring device 6 is ≥4.5De-7.5De (preferably ≥5De) away from the upstream straight pipe length of the water outlet straight pipe section 41, and is ≥1.5De-4De (preferably ≥2De) away from the downstream straight pipe length of the water outlet straight pipe section 41; the cooling water flow measuring device 7 is ≥9De-12De (preferably ≥10De) away from the upstream straight pipe length of the water outlet straight pipe section 41, and is ≥4.5De-7.5De (preferably ≥5De) away from the downstream straight pipe length of the water outlet straight pipe section 41.

[0091] In the application, see Figure 1 , cooling water enters from the cooling water inlet pipe 3 and is discharged from the cooling water outlet pipe 4. Therefore, the upstream and downstream in this scheme are based on the water inlet direction as the upstream and the water outlet direction as the downstream; taking the cooling water inlet pipe 3 as an example, the water flow direction is from the outside to the refrigeration unit 1, then its upstream refers to the first cooling water temperature measuring device 5 as the boundary, and the area from the outside to the first cooling water temperature measuring device 5 is called the upstream, and after passing through the first cooling water temperature measuring device 5, it is called the downstream. Taking the cooling water outlet pipe 4 as an example, the water flow direction is from the refrigeration unit 1 to the outside, then its upstream refers to the second cooling water temperature measuring device 6 as the boundary, and the area from the refrigeration unit 1 to the second cooling water temperature measuring device 6 is called the upstream, and after passing through the second cooling water temperature measuring device 6, it is called the downstream.

[0092] In the application, in order to avoid the bends, obstacles and other areas in the pipeline blocking the cooling water, thus affecting the detection accuracy, the upstream and downstream areas of the water temperature and water flow measurement devices should be set as straight pipe sections. After research, the straight pipe length in this scheme can ensure the accuracy of the measurement data. At the same time, the position of the measurement point can be adapted according to different pipelines, making it have a wider range of applications. The De is the hydraulic diameter of the pipeline, which refers to the ratio of four times the flow cross-sectional area to the circumference.

[0093] Embodiment 2:

[0094] See also Figure 4-Figure 5 The temperature measuring device 22 is arranged at the rear side of the air cooler 21, 200mm-300mm away from the air cooler 21, 100mm-200mm away from the rear plate 23 of the cold storage 2, and 400mm-600mm away from the top plate 24 of the cold storage 2.

[0095] In the application, the temperature measuring device 22 is used to measure the actual temperature in the cold storage. This temperature does not participate in the calculation. However, when measuring other data, it is necessary to collect data at the designed temperature to ensure the accuracy of the data. The setting position is selected to be behind the side of the cold air fan 21 to avoid the influence of the air outlet of the cold air fan 21 on the temperature measurement. The distance to the storage board is to prevent the cold storage wall from affecting the temperature measurement. At the same time, the temperature here is the return air temperature of the cold air fan 21, which has good temperature stability and can reflect the temperature conditions in the storage.

[0096] Embodiment 3:

[0097] A method for measuring the energy efficiency of a real ship for a marine refrigeration system, the method comprising:

[0098] S1, setting the measurement section positions of the first cooling water temperature measuring device 5 and the second cooling water temperature measuring device 6;

[0099] The measuring section of the first cooling water temperature measuring device 5 is set at a distance of ≥4.5De-7.5De from the upstream straight pipe section 31 and ≥1.5De-4De from the downstream straight pipe section 31;

[0100] The measuring section of the second cooling water temperature measuring device 6 is set at a distance of ≥5De-7.5De from the upstream straight pipe section 41 of the water outlet straight pipe section, and ≥2De-4De from the downstream straight pipe section 41 of the water outlet straight pipe section;

[0101] S2, setting the measurement section position of the cooling water flow measurement device 7;

[0102] The measuring section of the cooling water flow measuring device 7 is set at a distance of ≥9De-12De from the upstream straight pipe section 41 of the water outlet straight pipe section, and ≥4.5De-7.5De from the downstream straight pipe section 41 of the water outlet straight pipe section;

[0103] S3, setting a temperature measuring device 22 and obtaining the temperatures in the plurality of cold storages 2; if the temperatures in the plurality of cold storages 2 all meet the preset measurement temperature, proceeding to step S4;

[0104] S4, based on the first cooling water temperature measuring device 5 and the second cooling water temperature measuring device 6, obtain the cooling water inlet temperature and outlet temperature; based on the cooling water flow measuring device 7, obtain the cooling water flow; based on the first voltage and current measuring device 81 and the second voltage and current measuring device 82, obtain the motor working voltage and current; based on the power factor measuring device 83, obtain the power factor;

[0105] S5. Based on the energy efficiency calculation formula, calculate the energy efficiency of the refrigeration system; the calculation expression is as follows:

[0106]

[0107] Where: η is the energy efficiency of the refrigeration system, Q is the output cooling capacity, P in is the input power;

[0108] The input power P in The calculation formula is as follows:

[0109]

[0110] Among them: U n is the input working voltage of the nth air cooler, I n is the average working current of the motor of the nth air cooler, is the power factor;

[0111] The calculation formula of the output cooling capacity Q is as follows:

[0112] Q=Q w -P in ;

[0113] Where: Q w The heat removed by cooling water;

[0114] Q w =C*m*(t out -t in );

[0115] Where: C is the specific heat of water, m is the cooling water flow rate, t out is the cooling water outlet temperature, t in is the cooling water inlet temperature;

[0116] S6. Based on steps S4-S5, repeatedly obtain the energy efficiency η of the refrigeration system several times 1 , η 2 ,…,η n , and calculate the comprehensive average energy efficiency of the refrigeration system; the calculation formula of the average energy efficiency is as follows:

[0117]

[0118] Where: η 平均 is the comprehensive average energy efficiency of the refrigeration system, and n is the number of times the energy efficiency of the refrigeration system is obtained. This average energy efficiency can be used as a reference value for the energy efficiency of the marine refrigeration system.

[0119] In application, the cooling types of marine refrigeration systems include air-cooled refrigeration systems and water-cooled refrigeration systems. The present technical solution is directed to a water-cooled refrigeration unit.

[0120] In application, the first voltage and current measuring device 81 and the second voltage and current measuring device 82 are arranged on the compressor and air cooler circuits corresponding to the main circuit in the control box and are appropriately fixed; the power factor measuring device 83 is arranged on the main circuit in the control box and is appropriately fixed.

[0121] In this embodiment, an example test was conducted based on a ship refrigeration system. There are two types of data required for refrigeration system energy efficiency monitoring. One is the data collection of new sensors, including: compressor current 1 + air cooler current 3 + temperature in the warehouse 3 + cooling water temperature 2 + cooling water flow 1 = 10; the other is to read data directly from the existing system, including: three-phase power supply voltage 3 + power supply power factor = 4, a total of 14 data, the detailed list of data selected for transmission is shown in the following table.

[0122] The data acquired by the data acquisition system with the newly added sensors are as follows:

[0123]

[0124] The data directly read from the existing system are:

[0125] Serial number Monitoring data Monitoring location Data collection method Output signal 1 Supply voltage L1-L2 Energy efficiency testing system Read in system Communication data 2 Supply voltage L2-L3 Energy efficiency testing system Read in system Communication data 3 Supply voltage L1-L3 Energy efficiency testing system Read in system Communication data 4 Power Factor Energy efficiency testing system Read in system Communication data

[0126] In this embodiment, based on the technical indicators of a ship refrigeration system, the data measured, input or read is shown in the following table:

[0127]

[0128] Based on the data measured, input or read in the above table, in this embodiment, energy efficiency calculations for three batches are performed for three cold storages, and the specific calculations are as follows:

[0129] The power loss of the first batch of systems is:

[0130]

[0131] The first batch output cooling capacity is:

[0132]

[0133] The energy efficiency of the first batch of refrigeration systems is:

[0134]

[0135] The power loss of the second batch system is:

[0136]

[0137] The second batch output cooling capacity is:

[0138]

[0139] The energy efficiency of the second batch of refrigeration systems is:

[0140]

[0141] The power loss of the third batch system is:

[0142]

[0143] The third batch output cooling capacity is:

[0144]

[0145] The energy efficiency of the third batch of refrigeration systems is:

[0146]

[0147] Combining the energy efficiency of the three batches, the comprehensive average energy efficiency of the refrigeration system is:

[0148]

[0149] By calculating the average value of energy efficiency in multiple batches, the error of single calculation is avoided and the accuracy of energy efficiency calculation is improved.

[0150] In this embodiment, the efficiency of the refrigeration system is effectively obtained through example testing, and a complete theoretical and example basis is provided for the testing, installation, calculation and other processes of the energy efficiency of the refrigeration system of a real ship, ensuring the accuracy of the efficiency results of the refrigeration system.

[0151] Although the embodiments of the present invention have been shown and described above, it should be understood that the above embodiments are exemplary and should not be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A real ship energy efficiency measurement system for a marine refrigeration system, characterized in that: The refrigeration system comprises a refrigeration unit (1), a plurality of cold storages (2), a cooling water inlet pipe (3), and a cooling water outlet pipe (4); a cooling fan (21) and a temperature measuring device (22) are provided in each of the plurality of cold storages (2); The measurement system comprises a first cooling water temperature measuring device (5), a second cooling water temperature measuring device (6), a cooling water flow measuring device (7), and a control box (8); the control box (8) is electrically connected to the refrigeration unit (1), and a first voltage and current measuring device (81), a second voltage and current measuring device (82), and a power factor measuring device (83) are arranged in the control box (8); the cooling water inlet pipe (3) and the cooling water outlet pipe (4) are both connected to the refrigeration unit (1), and the refrigeration unit (1) is connected to a plurality of cold storages (2); The first cooling water temperature measuring device (5) is arranged on the water inlet straight pipe section (31) of the cooling water inlet pipe (3); the first cooling water temperature measuring device (5) is ≥4.5De-7.5De away from the upstream straight pipe section (31) and ≥1.5De-4De away from the downstream straight pipe section (31); The second cooling water temperature measuring device (6) and the cooling water flow measuring device (7) are arranged on the outlet straight pipe section (41) of the cooling water outlet pipe (4); the distance between the second cooling water temperature measuring device (6) and the outlet straight pipe section (41) is ≥4.5De-7.5De upstream, and ≥4.5De downstream. 1.5De-4De; the cooling water flow rate measuring device (7) is ≥9De-12De away from the upstream straight pipe section (41) of the water outlet, and is ≥4.5De-7.5De away from the downstream straight pipe section (41) of the water outlet.

2. The real ship energy efficiency measurement system for a marine refrigeration system according to claim 1 is characterized in that: The temperature measuring device (22) is arranged at the rear side of the cooling fan (21) and at a distance of 1.5 m from the cooling fan (21). 200mm-300mm, and 100mm-200mm away from the rear panel (23) of the cold storage (2), and 400mm-600mm away from the top panel (24) of the cold storage (2).

3. The real ship energy efficiency measurement system for a marine refrigeration system according to claim 1 is characterized in that: The first cooling water temperature measuring device (5) is at a distance of ≥5De from the upstream straight pipe section (31) of the water inlet straight pipe section, and at a distance of ≥2De from the downstream straight pipe section (31) of the water inlet straight pipe section; The second cooling water temperature measuring device (6) is at a distance of ≥5De from the upstream straight pipe section (41) of the water outlet straight pipe section, and at a distance of ≥2De from the downstream straight pipe section (41) of the water outlet straight pipe section; The cooling water flow measurement device (7) is located at a distance of ≥10 De from the upstream straight pipe section (41) of the water outlet straight pipe section, and is located at a distance of ≥5 De from the downstream straight pipe section (41) of the water outlet straight pipe section.

4. A method for measuring the energy efficiency of a real ship for a marine refrigeration system, characterized in that: The method comprises: S1, setting the measurement section positions of the first cooling water temperature measuring device (5) and the second cooling water temperature measuring device (6); The measuring section of the first cooling water temperature measuring device (5) is arranged at a distance of ≥4.5De-7.5De from the upstream straight pipe section (31) of the water inlet straight pipe section, and at a distance of ≥1.5De-4De from the downstream straight pipe section (31) of the water inlet straight pipe section; The measuring section of the second cooling water temperature measuring device (6) is arranged at a distance of ≥5De-7.5De from the upstream straight pipe section (41) of the water outlet straight pipe section, and at a distance of ≥2De-4De from the downstream straight pipe section (41) of the water outlet straight pipe section; S2, setting the measurement section position of the cooling water flow measurement device (7); The measuring section of the cooling water flow measuring device (7) is arranged at a distance of ≥9De-12De from the upstream straight pipe section (41) of the water outlet straight pipe section, and at a distance of ≥4.5De-7.5De from the downstream straight pipe section (41) of the water outlet straight pipe section; S3, setting a temperature measuring device (22) and obtaining the temperatures in the plurality of cold storages (2); if the temperatures in the plurality of cold storages (2) all meet the preset measurement temperature, proceeding to step S4; S4, obtaining the cooling water inlet temperature and outlet temperature based on the first cooling water temperature measuring device (5) and the second cooling water temperature measuring device (6); obtaining the cooling water flow rate based on the cooling water flow rate measuring device (7); obtaining the motor operating voltage and current based on the first voltage and current measuring device (81) and the second voltage and current measuring device (82); obtaining the power factor based on the power factor measuring device (83); S5. Based on the energy efficiency calculation formula, calculate the energy efficiency of the refrigeration system; the calculation expression is as follows: Where: η is the energy efficiency of the refrigeration system, Q is the output cooling capacity, P in is the input power; S6. Based on steps S4-S5, repeatedly obtain the energy efficiency η1, η2, ..., η of the refrigeration system several times n , and calculate the comprehensive average energy efficiency of the refrigeration system; the calculation formula of the average energy efficiency is as follows: Where: η 平均 is the comprehensive average energy efficiency of the refrigeration system, and n is the number of times the energy efficiency of the refrigeration system is obtained.

5. The actual ship energy efficiency measurement method for a marine refrigeration system according to claim 4 is characterized in that: The input power P in The calculation formula is as follows: Among them: U n is the input working voltage of the nth air cooler, I n is the average working current of the motor of the nth air cooler, is the power factor; The calculation formula of the output cooling capacity Q is as follows: Q=Q w -P in ; Where: Q w The heat removed by cooling water; Q w =C*m*(t ou -t in ); Where: C is the specific heat of water, m is the cooling water flow rate, t out is the cooling water outlet temperature, t in is the cooling water inlet temperature.

6. The actual ship energy efficiency measurement method for a marine refrigeration system according to claim 4 is characterized in that: The measuring section of the first cooling water temperature measuring device (5) is arranged at a distance of ≥5De from the upstream straight pipe section (31) of the water inlet straight pipe section, and at a distance of ≥2De from the downstream straight pipe section (31) of the water inlet straight pipe section; The measuring section of the second cooling water temperature measuring device (6) is arranged at a distance of ≥5De from the upstream straight pipe section (41) of the water outlet straight pipe section, and at a distance of ≥2De from the downstream straight pipe section (41) of the water outlet straight pipe section; The measuring section of the cooling water flow measuring device (7) is arranged at a distance of ≥10De from the upstream straight pipe section (41) of the water outlet straight pipe section, and at a distance of ≥5De from the downstream straight pipe section (41) of the water outlet straight pipe section.

7. The actual ship energy efficiency measurement method for a marine refrigeration system according to claim 4 is characterized in that: In step S3, the temperature measuring device (22) is arranged at the rear side of the air cooler (21), at a distance of ≥200 mm from the air cooler (21), at a distance of ≥100 mm from the rear panel (23) of the cold storage (2), and at a distance of ≥500 mm from the top panel (24) of the cold storage (2).

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